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Abstract: A 23-year-old woman underwent a near-total thyroidectomy approximately 4 months prior due to papillary carcinoma. To eliminate residual thyroid tissue, she was administered 130 mCi of 131I during her initial radioiodine therapy session. After receiving therapy for 3 days, a focus of radioiodine uptake was noted in the left pelvic cavity on the posttherapy 131I whole-body image. Further analysis using SPECT/CT imaging pinpointed the uptake to the left ovary. Histopathological findings confirmed the presence of a mature teratoma in the ovary., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Poly (ADP-ribose) polymerase inhibitors (PARPi) have become a new standard of care for the maintenance treatment of advanced epithelial ovarian cancer. This study aims to evaluate the efficacy and safety of combining stereotactic body radiotherapy with PARPi continuation as a strategy to treat ovarian cancer oligoprogression on PARPi., Methods: This is a multicenter retrospective study including ovarian cancer patients treated with stereotactic body radiotherapy and PARPi continuation for oligoprogression under PARPi maintenance therapy between June 2012 and May 2023 in three Italian centers. PARPi treatment was continued until further disease progression or unacceptable toxicity. The primary endpoint was the next-line systemic therapy-free interval. The Kaplan-Meier method was used to assess local control, progression-free survival, and overall survival. Univariate and multivariate Cox regression analyses were performed to evaluate potential clinical outcomes predictors., Results: 46 patients were included, with a total of 89 lesions treated over 63 radiotherapy treatments. Lymph nodes were the most frequently treated lesions (80, 89.9%), followed by visceral lesions (8, 9%) and one case with a bone lesion (1.1%). Median follow-up was 25.9 months (range 2.8-122). The median next-line systemic therapy-free interval was 12.4 months (95% CI 8.3 to 19.5). A number of prior chemotherapy lines greater than five was significantly associated with a reduced next-line systemic therapy-free interval (HR 3.21, 95% CI 1.11 to 9.32, p=0.032). At the time of analysis, 32 (69.6%) patients started a new systemic therapy regimen, while 14 (30.4%) remained on the PARPi regimen. The 2-year progression-free survival, local failure-free survival, and overall survival rates were 10.7%, 78.1%, and 76.5%, respectively. Four patients (8.7%) experienced acute toxicity with G1 gastrointestinal events., Conclusion: Stereotactic body radiotherapy combined with PARPi continuation may be an effective and safe strategy for managing ovarian cancer patients with oligoprogression on PARPi maintenance therapy. Prospective research is warranted to shed more light on this approach., Competing Interests: Competing interests: BAJ-F has received speakers fees from Roche, Bayer, Janssen, Carl Zeiss, Ipsen, Accuray, Astellas, Elekta, and IBA Astra Zeneca, all outside the current project., (© IGCS and ESGO 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Malignant struma ovarii (MSO) is a rare ovarian teratoma composed primarily of thyroid tissue. Common sites of metastasis include peritoneum, bone, liver, lung, gastrointestinal tract and omentum. We present a woman in her 50s with a history of remote oophorectomy presenting with hypopituitarism and a 2.7 cm sellar mass. Trans-sphenoidal surgery for presumed pituitary macroadenoma achieved near total resection and resultant pathology surprisingly showed ectopic thyroid tissue. The patient acquired her ovarian pathology report from Southeast Asia which showed struma ovarii of the left ovary. The pituitary mass was thus determined to be a metastatic lesion from MSO. She underwent total thyroidectomy and radioactive iodine ablation therapy with good initial response and no regrowth of the tissue or emergence of distant metastases after 5 years of annual follow-up. To our knowledge, this is the first reported case of MSO to the pituitary., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Ovarian cancer (OC) is the most lethal gynecologic malignancy (5-y overall survival rate, 46%). OC is generally detected when it has already spread to the peritoneal cavity (peritoneal carcinomatosis). This study investigated whether gadolinium-based nanoparticles (Gd-NPs) increase the efficacy of targeted radionuclide therapy using [ 177 Lu]Lu-DOTA-trastuzumab (an antibody against human epidermal growth factor receptor 2). Gd-NPs have radiosensitizing effects in conventional external-beam radiotherapy and have been tested in clinical phase II trials. Methods: First, the optimal activity of [ 177 Lu]Lu-DOTA-trastuzumab (10, 5, or 2.5 MBq) combined or not with 10 mg of Gd-NPs (single injection) was investigated in athymic mice bearing intraperitoneal OC cell (human epidermal growth factor receptor 2-positive) tumor xenografts. Next, the therapeutic efficacy and toxicity of 5 MBq of [ 177 Lu]Lu-DOTA-trastuzumab with Gd-NPs (3 administration regimens) were evaluated. NaCl, trastuzumab plus Gd-NPs, and [ 177 Lu]Lu-DOTA-trastuzumab alone were used as controls. Biodistribution and dosimetry were determined, and Monte Carlo simulation of energy deposits was performed. Lastly, Gd-NPs' subcellular localization and uptake, and the cytotoxic effects of the combination, were investigated in 3 cancer cell lines to obtain insights into the involved mechanisms. Results: The optimal [ 177 Lu]Lu-DOTA-trastuzumab activity when combined with Gd-NPs was 5 MBq. Moreover, compared with [ 177 Lu]Lu-DOTA-trastuzumab alone, the strongest therapeutic efficacy (tumor mass reduction) was obtained with 2 injections of 5 mg of Gd-NPs/d (separated by 6 h) at 24 and 72 h after injection of 5 MBq of [ 177 Lu]Lu-DOTA-trastuzumab. In vitro experiments showed that Gd-NPs colocalized with lysosomes and that their radiosensitizing effect was mediated by oxidative stress and inhibited by deferiprone, an iron chelator. Exposure of Gd-NPs to 177 Lu increased the Auger electron yield but not the absorbed dose. Conclusion: Targeted radionuclide therapy can be combined with Gd-NPs to increase the therapeutic effect and reduce the injected activities. As Gd-NPs are already used in the clinic, this combination could be a new therapeutic approach for patients with ovarian peritoneal carcinomatosis., (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)

Intramedullary spinal cord metastasis(ISCM)often causes spinal cord neuropathy and should be treated as an oncologic emergency. However, it recurs in most cases after treatment, ISCM is a disease with a very unfavorable prognosis. Herein, we report a successfully treated case of ISCM with emergent and high-dose radiotherapy. A 53-year-old woman had difficulty walking without assistance 2 years after surgery for ovarian cancer. She received emergent radiotherapy at a total dose of 50 Gy in 25 fractions. Her neurological symptoms dramatically improved over 3 weeks after radiotherapy. ISCM has been controlled using the imaging tests at 5 years after radiotherapy. We believe that both emergent and high-dose radiotherapy were effective for ISCM.

Background: Efforts have been made to investigate the role of salvage radiotherapy (RT) in treating recurrent ovarian cancer (ROC). Stereotactic ablative radiation therapy (SABR) is a state-of-the-art therapy that uses intensity modulation to increase the fractional dose, decrease the number of fractions, and target tumors with high precision., Methods: The SABR-ROC trial is a phase 3, multicenter, randomized, prospective study to evaluate whether the addition of SABR to the standard of care significantly improves the 3-year overall survival (OS) of patients with ROC. Patients who have completed the standard treatment for primary epithelial ovarian cancer are eligible. In addition, patients with number of metastases ≤ 10 and maximum diameter of each metastatic site of gross tumor ≤ 5 cm are allowed. Randomization will be stratified by (1) No. of the following clinical factors met, platinum sensitivity, absence of ascites, normal level of CA125, and ECOG performance status of 0-1; 0-3 vs. 4; (2) site of recurrence; with vs. without lymph nodes; and (3) PARP inhibitor; use vs. non-use. The target number of patients to be enrolled in this study is 270. Participants will be randomized in a 1:2 ratio. Participants in Arm 2 will receive SABR for recurrent lesions clearly identified in imaging tests as well as the standard of care (Arm 1) based on treatment guidelines and decisions made in multidisciplinary discussions. The RT fraction number can range from 1 to 10, and the accepted dose range is 16-45 Gy. The RT Quality Assurance (QA) program consists of a three-tiered system: general credentialing, trial-specific credentialing, and individual case reviews., Discussion: SABR appears to be preferable as it does not interfere with the schedule of systemic treatment by minimizing the elapsed days of RT. The synergistic effect between systemic treatment and SABR is expected to reduce the tumor burden by eradicating gross tumors identified through imaging with SABR and controlling microscopic cancer with systemic treatment. It might also be beneficial for quality-of-life preservation in older adults or heavily treated patients., Trial Registration: This trial was registered at ClinicalTrials.gov (NCT05444270) on June 29th, 2022., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Purpose: This retrospective, multicenter study analyzes the efficacy and safety of stereotactic body radiation therapy in a large cohort of patients with oligometastatic/persistent/recurrent uterine cancer., Methods and Materials: Clinical and radiation therapy data from several radiation therapy centers treating patients by stereotactic body radiation therapy between March 2006 and October 2021 were collected. Objective response rate was defined as complete and partial response, and clinical benefit included objective response rate plus stable disease. Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Common Terminology Criteria for Adverse Events scales were used to grade toxicities. Primary endpoints were the rate of complete response to stereotactic body radiation therapy, and the 2-year actuarial local control rate "per-lesion" basis. Secondary endpoints were progression-free survival and overall survival, as well as toxicity., Results: In the study, 157 patients with oligometastatic/persistent/recurrent uterine cancer bearing 272 lesions treated by stereotactic body radiation therapy at 14 centers were analyzed. Lymph node metastases (137, 50.4%) were prevalent, followed by parenchyma lesions (135, 49.6%). Median total dose was 35 Gy (10-75.2), in 5 fractions (range, 1-10). Complete and partial responses were 174 (64.0%), and 54 (19.9%), respectively. Stable disease was registered in 29 (10.6%), and 15 (5.5%) lesions progressed. Type of lesion (lymph node), volume (≤13.7 cc) and total dose (BED 10 >59.5 Gy) were significantly associated with a higher probability of achieving complete response. Patients achieving complete response (CR) "per-lesion" basis experienced a 2-year actuarial local control rate of 92.4% versus 33.5% in lesions not achieving complete response (NCR; P < .001). Moreover, the 2-year actuarial progression-free survival rate in patients with CR was 45.4%, and patients with NCR had a 2-year rate of 17.6% (P < .001). Finally, patients who had a CR had a 2-year overall survival rate of 82.7%, compared with 56.5% for NCR patients (P <.001). Severe acute toxicity was around 2%, including one toxic death due to gastric perforation, and severe late toxicity around 4%., Conclusions: The efficacy of stereotactic body radiation therapy in this setting was confirmed. The low toxicity profile and the high local control rate in complete responder patients encourage the wider use of this approach., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Advanced ovarian cancer currently has few therapeutic options. Poly(ADP-ribose) polymerase (PARP) inhibitors bind to nuclear PARP and trap the protein-inhibitor complex to DNA. This work investigates a theranostic PARP inhibitor for targeted radiopharmaceutical therapy of ovarian cancer in vitro and PET imaging of healthy mice in vivo., Methods: [ 77 Br]RD1 was synthesized and assessed for pharmacokinetics and cytotoxicity in human and murine ovarian cancer cell lines. [ 76 Br]RD1 biodistribution and organ uptake in healthy mice were quantified through longitudinal PET/CT imaging and ex vivo radioactivity measurements. Organ-level dosimetry following [ 76/77 Br]RD1 administration was calculated using RAPID, an in-house platform for absorbed dose in mice, and OLINDA for equivalent and effective dose in human., Results: The maximum specific binding (B max ), equilibrium dissociation constant (K d ), and nonspecific binding slope (NS) were calculated for each cell line. These values were used to calculate the cell specific activity uptake for cell viability studies. The half maximal effective concentration (EC 50 ) was measured as 0.17 (95 % CI: 0.13-0.24) nM and 0.46 (0.13-0.24) nM for PARP(+) and PARP(-) expressing cell lines, respectively. The EC 50 was 0.27 (0.21-0.36) nM and 0.30 (0.22-0.41) nM for BRCA1(-) and BRCA1(+) expressing cell lines, respectively. When measuring the EC 50 as a function of cellular activity uptake and nuclear dose, the EC 50 ranges from 0.020 to 0.039 Bq/cell and 3.3-9.2 Gy, respectively. Excretion through the hepatobiliary and renal pathways were observed in mice, with liver uptake of 2.3 ± 0.4 %ID/g after 48 h, contributing to estimated absorbed dose values in mice of 19.3 ± 0.3 mGy/MBq and 290 ± 10 mGy/MBq for [ 77 Br]RD1 and [ 76 Br]RD1, respectively., Conclusion: [ 77 Br]RD1 cytotoxicity was dependent on PARP expression and independent of BRCA1 status. The in vitro results suggest that [ 77 Br]RD1 cytotoxicity is driven by the targeted Meitner-Auger electron (MAe) radiotherapeutic effect of the agent. Further studies investigating the theranostic potential, organ dose, and tumor uptake of [ 76/77 Br]RD1 are warranted., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: To assess the response rate and survival effect of adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) during ovarian clear cell carcinoma (OCCC)., Methods: We searched Web of Science, PubMed, Cochrane library electronic databases, Clinical Trials, WanFang Data and Chinese National Knowledge Infrastructure (CNKI) up to October 2022. We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies., Results: We identified a total of 4259 patients from 14 studies met the inclusion criteria. The pooled response rate of residual tumors for RT/CRT was 80.0%, the pooled 5-year progression-free survival (PFS) ratio during RT/CRT group was 61.0%, and the pooled 5-year overall survival (OS) ratio during RT/CRT group was 68.0%; heterogeneity tests demonstrated significant difference between studies (I 2 >50%). Cumulative results suggested adjuvant RT/CRT improved 5-year PFS ratio of OCCC patients (OR: 0.51 (95% CI: 0.42-.88), I 2 = 22%, P = .009), had no impact on 5-year OS ratio (OR: 0.52 (95% CI: 0.19-1.44), I 2 = 87%, P = .21); meta-regression of studies before and after 2000 found consistent results. Sub-analysis observed that adjuvant RT/CRT had no impact on 5-year OS ratio of early-stage (stage I + II) OCCC patients (OR: 0.67 (95% CI: 0.25-1.83), I 2 = 85%, P = .44), but might improve 5-year OS ratio of advanced and recurrent OCCC patients (OR: 0.13(95% CI: 0.04-.44), P = .001)., Conclusion: This analysis suggested that adjuvant RT/CRT might improve oncologic outcomes of OCCC, especially for advanced and recurrent cases. Due to the inherent selective biases of retrospective studies enrolled in the meta-analysis, more convincing evidences based on prospective randomized controlled trials (RCTs) are urgently needed.

Background: Radiation therapy is regarded as an effective treatment for early ovarian cancer (OC). However, due to radiation resistance caused by DNA double-strand breaks (DSBs) and angiogenesis, the efficacy of radiotherapy for advanced OC is limited and controversial., Purpose: To explore whether ultrasound-stimulated microbubbles (USMBs) can enhance the radiosensitivity of OC., Material and Methods: OC cells (ES-2) were respectively irradiated with 5-Gy and 10-Gy radiation doses with or without exposure to USMB. Methyl thiazolyltetrazolium (MTT) and colony-formation assays were conducted to detect the viability and proliferation of ES-2 cells after USMBs and ionizing radiation (IR) treatment. Immunofluorescence assays were conducted to examine levels of gamma-H2A histone family member X (γ-H2AX), an indicator for DSBs. Flow cytometry analyses were carried out to assess the apoptosis of ES-2 cells. The angiogenic activity of human umbilical vein endothelial cells (HUVECs) was measured by tube formation assays., Results: USMBs enhanced IR-induced suppressive effect on the viability and proliferation of OC cells. The protein levels of phosphorylated γ-H2AX and CHK1 were significantly upregulated after IR treatment and further enhanced by USMBs. In addition, USMBs enhanced the promotion of IR-mediated OC cell apoptosis. The inhibitory effect of IR on angiogenesis was further enhanced by USMBs, and protein levels of AT1R, VEGFA, and EGFR were downregulated by IR in a dose-dependent way and then enhanced by USMB treatment in HUVECs., Conclusions: USMB exposure significantly enhances the radiosensitivity of OC by suppressing cell proliferation, promoting OC cell apoptosis, and inhibiting angiogenesis.

Introduction: Malignant struma ovarii (MSO) is a rare thyroid cancer arising within an ovarian teratoma. While surgical excision of the primary tumor is widely accepted as standard of care, recommendations for adjuvant treatment of MSO-whether or not to administer radioactive iodine (RAI)-are based largely on case reports and remain debated. In this study, we aimed to propose a risk stratification and analyze RAI utilization patterns in MSO cases. Methods: The National Cancer Database (NCDB) was queried for patients with MSO between 2004 and 2016. Demographic, oncological, and clinicopathologic data were compared between groups using Fisher's exact test. Kaplan-Meier curves were used to estimate overall survival (OS), and variables associated with OS were assessed via univariate Cox regression. We adapted the 2015 American Thyroid Association risk guidelines for MSO patients. We stratified patients into low-, intermediate-, and high-risk groups using metastasis, extraovarian extension, lymphovascular invasion, lymph node status, surgical margins, tumor size, and grade. Risk stratification, demographic, oncological, and clinicopathologic data were compared between the groups receiving and not receiving RAI therapy. We then queried the Surveillance, Epidemiology, and End Results (SEER) 18 registry for patients with MSO between 2000 and 2018 to confirm our risk stratification analysis. Results: In the NCDB analysis, a total of 158 patients were identified, and 19 received RAI. RAI therapy was associated with distant metastasis ( p  = 0.005) and lymph node status ( p  = 0.012). Twenty-one NCDB patients were stratified as high risk, and 30% of high-risk patients received RAI. High-risk stratification was associated with decreased OS via univariate Cox regression (hazard ratio = 4.0 [95% confidence interval 1.11-14.26], p  = 0.034). In our subsequent analysis using the SEER registry, there were 95 MSO patients, and 18 received RAI. Again, the majority of high-risk patients did not receive RAI, with only 41% of high-risk patients receiving RAI. Conclusions: MSO is a rare malignancy with apparently variable and inconsistent patterns of postoperative RAI administration. The risk stratification described here provides a framework to identify patients potentially at risk for mortality, and utilization of RAI in this group should be studied further.

Background: Stereotactic body radiotherapy (SBRT) has shown promising results in the clinical setting of oligometastatic, persistent, or recurrent disease in several malignancies including ovarian cancer., Primary Objective: The MITO-RT3/RAD trial is a prospective, multicenter phase II study aimed at identifying potential predictors of response and clinical outcome after SBRT treatment., Study Hypothesis: Radiotherapy delivered by pre-defined SBRT treatment schedules and shared constraints could improve the rate of complete response., Trial Design: All patients accrued will be treated with a radiotherapy dose in the range of 30-50 Gy by 1, 3, or 5 SBRT daily fractions to all sites of active metastatic disease according to diagnostic imaging. Schedules of treatment and dose prescription have been established before considering target sites and healthy organ dose constraints. Follow-up and monitoring of side effects will be carried out every 3 months for the first year with imaging and clinical evalutation, and every 4 months within the second year; thereafter, surveillance will be carried out every 6 months. The best response on a per lesion basis will be evaluated by computed tomographic (CT) scan, positron emission tomography/CT, or magnetic resonance imaging in case of brain lesions, every 3 months., Major Inclusion/exclusion Criteria: The study includes patients with oligometastatic, persistent, or recurrent ovarian cancer for which salvage surgery or other local therapies are not feasible due to any relative contra-indication to further systemic therapy because of serious co-morbidities, previous severe toxicity, unavailability of potentially active systemic therapy, or patient refusal., Primary Endpoint: The primary endpoint of the study is the clinical complete response rate to SBRT by imaging on a per lesion basis., Sample Size: Approximately 205 lesions will be treated (90 lymph nodes and 115 parenchyma lesions)., Estimated Dates for Completing Accrual and Presenting Results: Fifty-two centers have expressed their intention to participate. Enrollment should be completed by March 2023 and analysis will be completed in September 2023., Trial Registration: NCT04593381., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Oral administration (gavage) of a second-generation probiotic, Lactobacillus reuteri (L. reuteri), that releases interleukin-22 (LR-IL-22) at 24 h after total-body irradiation (TBI) mitigates damage to the intestine. We determined that LR-IL-22 also mitigates partial-body irradiation (PBI) and whole-abdomen irradiation (WAI). Irradiation can be an effective treatment for ovarian cancer, but its use is limited by intestinal toxicity. Strategies to mitigate toxicity are important and can revitalize this modality to treat ovarian cancer. In the present studies, we evaluated whether LR-IL-22 facilitates fractionated WAI in female C57BL/6 mice with disseminated ovarian cancer given a single fraction of either 15.75 Gy or 19.75 Gy or 4 daily fractions of 6 Gy or 6.5 Gy. Mice receiving single or multiple administrations of LR-IL-22 during WAI showed improved intestinal barrier integrity (P = 0.0167), reduced levels of radiation-induced intestinal cytokines including KC/CXCL1 (P = 0.002) and IFN-γ (P = 0.0024), and reduced levels of plasma, Eotaxin/CCL11 (P = 0.0088). LR-IL-22 significantly preserved the numbers of Lgr5+GFP+ intestinal stem cells (P = 0.0010) and improved survival (P < 0.0343). Female C57BL/6MUC-1 mice with widespread abdominal syngeneic 2F8cis ovarian cancer that received LR-IL-22 during 6.5 Gy WAI in 4 fractions had reduced tumor burden, less intestinal toxicity, and improved 30-day survival. Furthermore, LR-IL-22 facilitated WAI when added to Paclitaxel and Carboplatin chemotherapy and further increased survival. Oral administration (gavage) of LR-IL-22 is a potentially valuable intestinal radioprotector, which can facilitate therapeutic WAI for widespread intra-abdominal ovarian cancer., (©2022 by Radiation Research Society. All rights of reproduction in any form reserved.)

Background: The overexpression of human epidermal growth factor receptor 2 (HER2) is commonly associated with metastatic breast cancer and epithelial ovarian cancer. The U.S. Food and Drug Administration (FDA) has approved Trastuzumab as an anti-HER2 agent for the metastatic breast and epithelial ovarian cancer. However, Trastuzumab has severe limitations in the treatment of metastatic breast cancer associated with ligand-dependent dimerization of HER2 receptor at the extracellular domain-II (ECD-II) region. The therapeutic approach in combination of pertuzumab and trastuzumab is found to be effective in preventing HER2 dimerization at the ECD-II region. The radioimmunotherapeutic approach, utilizing both these anti-HER2 agents (trastuzumab/pertuzumab), radiolabeled with [ 177 Lu]Lu 3+ , has proved to be clinically efficacious with promising potential. Toward this, the formulation for clinical doses of [ 177 Lu]Lu-DOTA-pertuzumab has been optimized using medium specific activity (0.81 GBq/μg) [ 177 Lu]LuCl 3 . Materials and Methods: Preconcentrated pertuzumab was conjugated with p -NCS-benzyl-DOTA. Purified DOTA-benzyl-pertuzumab conjugate was radiolabeled with carrier-added [ 177 Lu]LuCl 3 . Quality control parameters were evaluated for the [ 177 Lu]Lu-DOTA-pertuzumab. In vivo biodistribution was carried out at different time points postadministration. Specific cell binding, immunoreactivity, and internalization were investigated by using SKOV3 and SKBR3 cells. Results: In this study, the authors reported a consistent and reproducible protocol for clinical dose formulations of [ 177 Lu]Lu-DOTA-pertuzumab, with a radiochemical yield of 86.67% ± 1.03% and radiochemical purity (RCP) of 99.36% ± 0.36% ( n  = 10). Preclinical cell binding studies of [ 177 Lu]Lu-DOTA-pertuzumab revealed specific binding with SKOV3 and SKBR3 cells up to 24.4% ± 1.4% and 23.2% ± 0.8%, respectively. The uptakes in SKOV3- and SKBR3-xenografted tumor in severe combined immunodeficiency mice were observed to be 25.9% ± 0.8% and 25.2% ± 1.2% ID/g at 48 and 120 h postinjection, respectively. Conclusions: A protocol was optimized for the preparation of ready-to-use clinical dose of [ 177 Lu]Lu-DOTA-pertuzumab, in hospital radiopharmacy settings. The retention of RCP of the radiopharmaceutical, on storage in saline and serum, at -20°C, up to 120 h postradiolabeling, confirmed its in vitro stability.

Treatment of advanced ovarian cancer using PD-1/PD-L1 immune checkpoint blockade shows promise; however, current clinical trials are limited by modest response rates. Radiotherapy has been shown to synergize with PD-1/PD-L1 blockade in some cancers but has not been utilized in advanced ovarian cancer due to toxicity associated with conventional abdominopelvic irradiation. Ultrahigh-dose rate (FLASH) irradiation has emerged as a strategy to reduce radiation-induced toxicity, however, the immunomodulatory properties of FLASH irradiation remain unknown. Here, we demonstrate that single high-dose abdominopelvic FLASH irradiation promoted intestinal regeneration and maintained tumor control in a preclinical mouse model of ovarian cancer. Reduced tumor burden in conventional and FLASH-treated mice was associated with an early decrease in intratumoral regulatory T cells and a late increase in cytolytic CD8 + T cells. Compared with conventional irradiation, FLASH irradiation increased intratumoral T-cell infiltration at early timepoints. Moreover, FLASH irradiation maintained the ability to increase intratumoral CD8 + T-cell infiltration and enhance the efficacy of αPD-1 therapy in preclinical models of ovarian cancer. These data highlight the potential for FLASH irradiation to improve the therapeutic efficacy of checkpoint inhibition in the treatment of ovarian cancer., (©2021 American Association for Cancer Research.)

Purpose: Stereotactic body radiation therapy is increasingly used to treat a variety of oligometastatic histologies, but few data exist for ovarian cancer. Ablative stereotactic body radiation therapy dosing is challenging in sites like the abdomen, pelvis, and central thorax due to proximity and motion of organs at risk. A novel radiation delivery method, stereotactic magnetic-resonance-guided online-adaptive radiation therapy (SMART), may improve the therapeutic index of stereotactic body radiation therapy through enhanced soft-tissue visualization, real-time nonionizing imaging, and ability to adapt to the anatomy-of-the-day, with the goal of producing systemic-therapy-free intervals. This phase I trial assessed feasibility, safety, and dosimetric advantage of SMART to treat ovarian oligometastases., Methods and Materials: Ten patients with recurrent oligometastatic ovarian cancer underwent SMART for oligometastasis ablation. Initial plans prescribed 35 Gy/5 fractions with goal 95% planning target volume coverage by 95% of prescription, with dose escalation permitted, subject to strict organ-at-risk dose constraints. Daily adaptive planning was used to protect organs-at-risk and/or increase target dose. Feasibility (successful delivery of >80% of fractions in the first on-table attempt) and safety of this approach was evaluated, in addition to efficacy, survival metrics, quality-of-life, prospective timing and dosimetric outcomes., Results: Ten women with seventeen ovarian oligometastases were treated with SMART, and 100% of treatment fractions were successfully delivered. Online adaptive plans were selected at time of treatment for 58% of fractions, due to initial plan violation of organs-at-risk constraints (84% of adapted fractions) or observed opportunity for planning target volume dose escalation (16% of adapted fractions), with a median on-table time of 64 minutes. A single Grade ≥3 acute (within 6 months of SMART) treatment-related toxicity (duodenal ulcer) was observed. Local control at 3 months was 94%; median progression-free survival was 10.9 months. Median Kaplan-Meier estimated systemic-therapy-free survival after radiation completion was 11.5 months, with concomitant quality-of-life improvements., Conclusions: SMART is feasible and safe for high-dose radiation therapy ablation of ovarian oligometastases of the abdomen, pelvis, and central thorax with minimal toxicity, high rates of local control, and prolonged systemic-therapy-free survival translating into improved quality-of-life., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Epithelial ovarian cancer is extremely difficult to treat due to its high recurrence rate and acquired tolerance to chemotherapy. Immune checkpoint inhibitors (ICIs) are expected to be promising solutions for treatment failure. However, the low response rate to a single ICI agent was demonstrated in approximately all published clinical trials. Surprisingly patients with complete response were also noticed as an anecdote. Proper indicators of treatment response were urgently required. Programmed death- ligand 1 expression levels in the tumor tissues provide relatively limited discrimination. Tumor mutation burden (TMB) serves as a more reliable parameter. Here we presented an ovarian cancer case with multiple gene mutations and high TMB, who benefited from a short-term treatment of pembrolizumab and experienced a long-lasting complete response of 2 years till now. The patient was irradiated in the pelvic before pembrolizumab. Our study demonstrated that ICIs might provide survival benefits for ovarian cancer with high TMB and that pelvic radiation might have synergistical effects with immunotherapy., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Developing strategies to inflame tumors is critical for increasing response to immunotherapy. Here, we report that low-dose radiotherapy (LDRT) of murine tumors promotes T-cell infiltration and enables responsiveness to combinatorial immunotherapy in an IFN-dependent manner. Treatment efficacy relied upon mobilizing both adaptive and innate immunity and depended on both cytotoxic CD4 + and CD8 + T cells. LDRT elicited predominantly CD4 + cells with features of exhausted effector cytotoxic cells, with a subset expressing NKG2D and exhibiting proliferative capacity, as well as a unique subset of activated dendritic cells expressing the NKG2D ligand RAE1. We translated these findings to a phase I clinical trial administering LDRT, low-dose cyclophosphamide, and immune checkpoint blockade to patients with immune-desert tumors. In responsive patients, the combinatorial treatment triggered T-cell infiltration, predominantly of CD4 + cells with Th1 signatures. Our data support the rational combination of LDRT with immunotherapy for effectively treating low T cell-infiltrated tumors. SIGNIFICANCE: Low-dose radiation reprogrammed the tumor microenvironment of tumors with scarce immune infiltration and together with immunotherapy induced simultaneous mobilization of innate and adaptive immunity, predominantly CD4 + effector T cells, to achieve tumor control dependent on NKG2D. The combination induced important responses in patients with metastatic immune-cold tumors. This article is highlighted in the In This Issue feature, p. 1 ., (©2021 The Authors; Published by the American Association for Cancer Research.)

Metastasis is the leading cause of cancer patient death, which is closely correlated with reactive oxygen species (ROS) levels. It is well known that the effects of ROS on tumors are diverse, depending on ROS concentration and cell type. We found that ovarian cancer cells have significantly lower levels of ROS than normal ovarian cells. Moreover, increased ROS levels in ovarian cancer cells can substantially inhibit their migration and invasion ability. Furthermore, the results show that moderate static magnetic field (SMF) can inhibit ovarian cancer cell migration, invasion, and stemness in a ROS-dependent manner. RNA sequencing results confirm that SMFs increased the oxidative stress level and reduced the stemness of ovarian cancer cells. Consistently, the expressions of stemness-related genes were significantly decreased, including hyaluronan receptor (CD44), SRY-box transcription factor 2 (Sox2), and cell myc proto-oncogene protein (C-myc). Furthermore, moderate SMFs provided by a superconducting magnet and permanent magnet have good biosafety and can both inhibit ovarian cancer metastasis in mice. Therefore, our study demonstrates the effects of SMFs on oxidative stress and metastasis in the ovarian cancer cells, which reveals the potential of applying SMF as a physical method in cancer therapy in the future., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Chao Song et al.)

The photophysical and photochemical properties of two Pt(IV)Re(I) conjugates were studied via both experimental and computational methods. Both conjugates exhibit modest photocytotoxicity against ovarian cancer cells. X-ray fluorescence microscopy showed that Pt and Re colocalize in cells whether they had been irradiated or not. This work demonstrates the potential of photoactivated multilimetallic agents for combating cancer.

Objective: Female patients treated with alkylating agents in childhood are at risk for ovarian impairment. We aimed at describing the pattern of residual ovarian function in a cohort of survivors of hematological malignancies and/or hematopoietic stem cell transplantation (HSCT) and assessing the relationship between cyclophosphamide equivalent dose (CED) and anti-Müllerian hormone (AMH)., Design and Methods: Gonadal health was clinically and biochemically assessed in 124 post-menarchal survivors who underwent treatment for pediatric hematological malignancies and/or HSCT between 1992 and 2019., Results: Overt 'premature ovarian insufficiency' (POI) was detected in 72.1 and 3.7% of transplanted and non-transplanted patients, respectively; milder 'diminished ovarian reserve' (DOR) in 16.3 and 22.2%. In non-transplanted patients, increasing CED values were associated with lower AMH-SDS (P = 0.04), with the threshold of 7200 g/m2 being the best discriminator between DOR/POI and normal ovarian function (AUC: 0.75 on ROC analysis) and with an observed decrease of 0.14 AMH-SDS for each CED increase of 1 g/m2. In addition, age at diagnosis ≥10 years played a detrimental role on ovarian reserve (P = 0.003). In the HSCT group, irradiation was associated with a statistically significant reduction in AMH-SDS (P = 0.04)., Conclusions: In non-transplanted patients, CED ≥ 7200 mg/m2 was associated with a DOR, while younger age at diagnosis played a protective role on ovarian reserve. As a result of the data collected, we propose a systematic algorithm to assess iatrogenic gonadal impairment in young female patients exposed to chemo-radiotherapy in childhood for hematological disorders.

Radiotherapy resistance is one of the key factors of poor prognosis of ovarian cancer clinical treatment. The search for key targets of ovarian cancer radiotherapy resistance has become a high priority. Long noncoding RNA plays an important role in tumor development. However, the key lncRNA in ovarian cancer radiotherapy resistance is not identified. Our finding that lncRNA CRNDE is highly expressed in the radiotherapy resistance cell line CAOV3/R drew our attention. Therefore, in this study, we targeted lncRNA CRNDE to analyze whether it is a key factor of radiotherapy resistance in ovarian cancer. Ultimately, we found that silencing lncRNA CRNDE could reverse CAOV3/R radiotherapy resistance, which would be a boon to clinical treatment., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wencui Yang et al.)

Background: Paclitaxel (Taxol) is a microtubule-stabilizing drug used to treat several solid tumors, including ovarian, breast, non-small cell lung, and pancreatic cancers. The current treatment of ovarian cancer is chemotherapy using paclitaxel in combination with carboplatin as a frontline agent, and paclitaxel is also used in salvage treatment as a second line drug with a dose intensive regimen following recurrence. More recently, a dose dense approach for paclitaxel has been used to treat metastatic breast cancer with success. Paclitaxel binds to beta tubulin with high affinity and stabilizes microtubule bundles. As a consequence of targeting microtubules, paclitaxel kills cancer cells through inhibition of mitosis, causing mitotic catastrophes, and by additional, not yet well defined non-mitotic mechanism(s)., Results: In exploring methods to modulate activity of paclitaxel in causing cancer cell death, we unexpectedly found that a brief exposure of paclitaxel-treated cells in culture to low intensity ultrasound waves prevented the paclitaxel-induced cytotoxicity and death of the cancer cells. The treatment with ultrasound shock waves was found to transiently disrupt the microtubule cytoskeleton and to eliminate paclitaxel-induced rigid microtubule bundles. When cellular microtubules were labelled with a fluorescent paclitaxel analog, exposure to ultrasound waves led to the disassembly of the labeled microtubules and localization of the signals to perinuclear compartments, which were determined to be lysosomes., Conclusions: We suggest that ultrasound disrupts the paclitaxel-induced rigid microtubule cytoskeleton, generating paclitaxel bound fragments that undergo degradation. A new microtubule network forms from tubulins that are not bound by paclitaxel. Hence, ultrasound shock waves are able to abolish paclitaxel impact on microtubules. Thus, our results demonstrate that a brief exposure to low intensity ultrasound can reduce and/or eliminate cytotoxicity associated with paclitaxel treatment of cancer cells in cultures., (© 2021. The Author(s).)

Objective: This study aimed to investigate incidence and risk for venous thromboembolism (VTE) according to primary treatment in women with ovarian cancer., Methods: We selected 26,863 women newly diagnosed with ovarian cancer between 2009 and 2018 from the Korean Health Insurance Review and Assessment Service databases. During the total follow-up period and the first six months after initiation of primary treatments, incidence and risk of VTE were evaluated according to primary treatment as no treatment, surgery, radiotherapy, or chemotherapy., Results: The mean follow-up period was 1285.5±6 days. The VTE incidence was highest in women who underwent chemotherapy (306 per 10,000 women). Among women who underwent surgery, VTE was highest in surgery with neoadjuvant chemotherapy (536 per 10,000 women), followed by surgery with adjuvant chemotherapy (360 per 10,000 women) and surgery alone (132 per 10,000 women). During the first 12 months, monthly incidence of VTE decreased. Compared with women with no treatment, risk of VTE significantly increased in women undergoing chemotherapy (HR 1.297; 95% CI, 1.08-1.557; P = 0.005) during the total follow-up period and decreased in women undergoing surgery (HR 0.557; 95% CI, 0.401-0.775; P<0.001) and radiotherapy (HR 0.289; 95% CI, 0.119-0.701; P = 0.006) during the first six months. Among women who underwent surgery, VTE risk significantly increased in surgery with neoadjuvant chemotherapy (HR 4.848; 95% CI, 1.86-12.632; P = 0.001) followed by surgery with adjuvant chemotherapy (HR 2.807; 95% CI, 1.757-4.485; P<0.001) compared with surgery alone during the total follow-up period and in surgery with neoadjuvant chemotherapy (HR 4.223; 95% CI, 1.37-13.022; P = 0.012) during the first six months., Conclusions: In this large Korean cohort study, incidence and risk of VTE were highest in women with ovarian cancer who underwent chemotherapy and surgery with neoadjuvant chemotherapy as a primary cancer treatment. Incidence of VTE decreased over time., Competing Interests: The authors have declared that no competing interests exist.

Alpha-particle emitting radionuclides continue to be the subject of medical research because of their high energy and short range of action that facilitate effective cancer therapies. Radium-224 (224Ra) is one such candidate that has been considered for use in combating micrometastatic disease. In our prior studies, a suspension of 224Ra-labeled calcium carbonate (CaCO3) microparticles was designed as a local therapy for disseminated cancers in the peritoneal cavity. The progenies of 224Ra, of which radon-220 (220Rn) is the first, together contribute three of the four alpha particles in the decay chain. The proximity of the progenies to the delivery site at the time of decay of the 224Ra-CaCO3 microparticles can impact its therapeutic efficacy. In this study, we show that the diffusion of 220Rn was reduced in labeled CaCO3 suspensions as compared with cationic 224Ra solutions, both in air and liquid volumes. Furthermore, free-floating lead-212 (212Pb), which is generated from released 220Rn, had the potential to be re-adsorbed onto CaCO3 microparticles. Under conditions mimicking an in vivo environment, more than 70% of the 212Pb was adsorbed onto the CaCO3 at microparticle concentrations above 1 mg/mL. Further, the diffusion of 220Rn seemed to occur whether the microparticles were labeled by the surface adsorption of 224Ra or if the 224Ra was incorporated into the bulk of the microparticles. The therapeutic benefit of differently labeled 224Ra-CaCO3 microparticles after intraperitoneal administration was similar when examined in mice bearing intraperitoneal ovarian cancer xenografts. In conclusion, both the release of 220Rn and re-adsorption of 212Pb are features that have implications for the radiotherapeutic use of 224Ra-labeled CaCO3 microparticles. The release of 220Rn through diffusion may extend the effective range of alpha-particle dose deposition, and the re-adsorption of the longer lived 212Pb onto the CaCO3 microparticles may enhance the retention of this nuclide in the peritoneal cavity., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: EN was employed by Oncoinvent AS at the time when her contribution to the research article occurred, and owns stock in Oncoinvent AS. ISJ, TBB and SW are employed and own stock in Oncoinvent AS. ØSB is a part-time consultant for and owns stock in Oncoinvent AS. RHL is chairman of the board of Oncoinvent AS and a shareholder. Oncoinvent AS holds intellectual property rights to the presented technology (patent name: Radiotherapeutic particles and suspensions. Patent number: US9539346 B1 and EP3111959 B1, inventors: RHL and SW). This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: To evaluate the initial experience and clinical utility of first-line adjuvant intensity-modulated whole abdominal radiation therapy (WART) in women with ovarian clear cell cancer (OCCC) referred to an academic center., Methods: Progression-free and overall survival was analyzed in a pragmatic observational cohort study of histologically pure OCCC patients over-expressing HNF-1ß treated between 2013 and end-December 2018. An in-house intensity-modulated WART program was developed from a published pre-clinical model. Radiation dose-volume data was curated to American Association of Physics in Medicine (AAPM) Task Group 263 recommendations. A dedicated database prospectively recorded presenting characteristics and outcomes in a standardized fashion., Results: Five women with FIGO (2018) stage IA to IIIA2 OCCC were treated with first-line WART. Median age was 58 years (range 47-68 years). At diagnosis CA-125 was elevated in 4 cases (median 56 kU/L: range 18.4-370 kU/L) before primary de-bulking surgery. Severe premorbid endometriosis was documented in 3 patients. At a median follow-up of 77 months (range 16-83 mo.), all patients remain alive and progression-free on clinical, biochemical (CA-125), and 18 Fluoro-deoxyglucose (FDG) PET/CT re-evaluation. Late radiation toxicity was significant (G3) in 1 case who required a limited bowel resection and chronic nutritional support at 9 months post-WART; 2 further patients had asymptomatic (G2) osteoporotic fragility fractures of axial skeleton at 12 months post-radiation treated with anti-resorptive agents (denosumab)., Conclusions: The clinical utility of intensity-modulated WART in OCCC over-expressing HNF-1β was suggested in this small observational cohort study. The hypothesis that HNF-1β is a portent of platinum-resistance and an important predictive biomarker in OCCC needs further confirmation. Curating multi-institutional cohort studies utilizing WART by means of "Big Data" may improve OCCC care standards in the future.

Background: Patients with advanced-stage ovarian cancer face a poor prognosis because of recurrent peritoneal cavity metastases following surgery and chemotherapy. Alpha-emitters may enable the efficient treatment of such disseminated diseases because of their short range and highly energetic radiation. Radium-224 is a candidate α-emitter due to its convenient 3.6-day half-life, with more than 90% of the decay energy originating from α-particles. However, its inherent skeletal accumulation must be overcome to facilitate intraperitoneal delivery of the radiation dose. Therefore, 224 Ra-labeled CaCO 3 microparticles have been developed., Objective: The antitumor effect of CaCO 3 microparticles as a carrier for 224 Ra was investigated, with an emphasis on the ratio of activity to mass dose of CaCO 3 , that is, specific activity., Methods: Nude athymic mice were inoculated intraperitoneally with human ovarian cancer cells (ES-2) and treated with a single intraperitoneal injection of 224 Ra-labeled CaCO 3 microparticles with varying combinations of mass and activity dose, or cationic 224 Ra in solution. Survival and ascites volume at sacrifice were evaluated., Results: Significant therapeutic effect was achieved for all tested specific activities ranging from 0.4 to 4.6 kBq/mg. Although treatment with a mean activity dose of 1305 kBq/kg of cationic 224 Ra prolonged the survival compared with the control, equivalent median survival could be achieved with 224 Ra-labeled microparticles with a mean dose of only 420 kBq/kg. The best outcome was achieved with the highest specific activities (2.6 and 4.6 kBq/mg)., Conclusion: Radium-224-labeled CaCO 3 microparticles present a promising therapy against cancer dissemination in body cavities., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: The development of Cancer Stem-like Cells (CSCs) is one of the main causes of ovarian cancer tolerance to radiotherapy. Autophagy is an adaptive process by which cells damage due to radiation. As a metabolite of riboflavin, lumiflavin can enhance the chemotherapeutic effects of cisplatin on ovarian cancer CSCs., Objective: This study aimed to investigate the synergistic effects of lumiflavin and ionising radiation on ovarian cancer CSCs and explore the association of this metabolite with autophagy., Methods: CSCs of human ovarian cancer cell lines HO8910 were treated with lumiflavin and rapamycin and then subjected to irradiation at a cumulative dose of 8 Gy. Cell proliferation ability, clonal formation ability, apoptosis rate, autophagy changes and autophagy-related protein changes were detected., Results: Lumiflavin and ionising radiation synergistically reduced cell vitality and clone formation and increased the apoptosis of CSCs compared with irradiation alone. In addition, ionising radiation increased autophagy and the expression of associated proteins, whereas lumiflavin reduced those changes in autophagy progression. Moreover, rapamycin, an autophagy inhibitor, was observed to block the synergistic effects of lumiflavin and ionising radiation on CSC apoptosis., Conclusion: Lumiflavin can enhance the effects of ionising radiation on ovarian cancer CSCs. The mechanism by which these effects are exerted is related to blocking the autophagy pathway., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose: Although radiotherapy is a common treatment option for all kinds of cancer patients, including ovarian cancer, a major obstacle limiting its application in the development of resistance. Therefore, it is urgently needed to clarify the mechanism of radiosensitivity modulation., Materials and Methods: We obtained open datasets and analyzed the expression of collagen type XI alpha 1 (COL11A1) in ovarian cancer patients with different stages. Meanwhile, the correlation of COL11A1 and survival outcomes is determined by Kaplan-Meier analysis. The role of COL11A1 in cell proliferation was observed in an in vitro knockdown system. SKOV3 radioresistant cells were established to determine the role of COL11A1 on radioresistant in ovarian cancer., Results and Discussion: COL11A1 were highly enriched in late-stage ovarian cancer tumor tissues and negatively correlated with survival outcomes in ovarian cancer. The functional analysis found that COL11A1 promoted ovarian cancer cell proliferation in vitro. Importantly, COL11A1 decreased radiosensitivity in ovarian cancer by AKT activation. Paired related homeobox 1 (PRRX1) acted as an upstream transcription factor to regulate COL11A1 expression in ovarian cancer. Increased COL11A1 expression is related to low survival outcomes and radiosensitivity in ovarian cancer., Conclusions: Targeting COL11A1 is a promising strategy for improving radiotherapy efficiency.

Objective: The objective of this study is to explore the role of miR-210 in the growth of ovarian cancer cells and the correlation with radiotherapy and to elucidate underlying molecular mechanisms., Methods: Human ovarian cancer cell lines OVCAR3 and SKOV3 were cultured in vitro, and miR-210 over-expression and low-expression ovarian cancer cell models were established by cell transfection. MTT assay was used to detect the proliferation activity. Transwell was used to detect the migration and invasion abilities. Western blot measured the expression of proteins related to cell proliferation, migration, and invasion. The cells were treated with different doses of ionizing radiation, and then the cell proliferation activity was detected by MTT. The expression of apoptosis-related proteins was detected by Western blot. The Caspase-Glo® Kit was used to detect the activity of cellular caspase 3/7 enzymes., Results: The proliferation, migration, and invasion abilities of miR-210 over-expression ovarian cancer cells were increased (p < 0.05), the expressions of PTEN and E-cadherin were decreased, and the expression of p-Protein kinase B (AKT), N-cadherin, Snail, and Vimentin were elevated. After ionizing radiation, the sensitivity of miR-210 over-expression cells to radiotherapy was decreased, the expression of apoptosis-related protein Bax was decreased, the expression of Bcl-2 was increased, and the activity of cellular caspase 3/7 enzyme was reduced (p < 0.05)., Conclusion: miR-210 can promote the proliferation, migration, and invasion of ovarian cancer cells by activating the AKT signaling pathway and regulating the expression of Epithelial-mesenchymal transition-related proteins. miR-210 can reduce the sensitivity of ovarian cancer cells to radiotherapy by inhibiting apoptosis, which might serve as a potential target for the treatment of ovarian tumors., (© 2020 S. Karger AG, Basel.)

Radioimmunotherapy, an approach using radiolabeled antibodies, has had minimal success in the clinic with several β-emitting radionuclides for the treatment of ovarian cancer. Alternatively, radioimmunotherapy with α-emitters offers the advantage of depositing much higher energy over shorter distances but was thought to be inappropriate for the treatment of solid tumors, for which antibody penetration is limited to a few cell diameters around the vascular system. However, the deposition of high-energy α-emitters to tumor markers adjacent to a typical leaky tumor vascular system may have large antitumor effects at the tumor vascular level, and their reduced penetration in normal tissue would be expected to lower off-target toxicity. Methods: To evaluate this concept, DOTAylated-huCC49 was labeled with the α-emitter 225 Ac to target tumor-associated glycoprotein 72-positive xenografts in a murine model of ovarian cancer. Results: 225 Ac-labeled DOTAylated-huCC49 radioimmunotherapy significantly reduced tumor growth in a dose-dependent manner (1.85, 3.7, and 7.4 kBq), with the 7.4-kBq dose extending survival by more than 3-fold compared with the untreated control. Additionally, a multitreatment regime (1.85 kBq followed by 5 weekly doses of 0.70 kBq for a total of 5.4 kBq) extended survival almost 3-fold compared with the untreated control group, without significant off-target toxicity. Conclusion: These results establish the potential for antibody-targeted α-radionuclide therapy for ovarian cancer, which may be generalized to α-radioimmunotherapy in other solid tumors., (© 2021 by the Society of Nuclear Medicine and Molecular Imaging.)

Radiation therapy is the most effective cytotoxic therapy for localized tumors. However, normal tissue toxicity limits the radiation dose and the curative potential of radiation therapy when treating larger target volumes. In particular, the highly radiosensitive intestine limits the use of radiation for patients with intra-abdominal tumors. In metastatic ovarian cancer, total abdominal irradiation (TAI) was used as an effective postsurgical adjuvant therapy in the management of abdominal metastases. However, TAI fell out of favor due to high toxicity of the intestine. Here we utilized an innovative preclinical irradiation platform to compare the safety and efficacy of TAI ultra-high dose rate FLASH irradiation to conventional dose rate (CONV) irradiation in mice. We demonstrate that single high dose TAI-FLASH produced less mortality from gastrointestinal syndrome, spared gut function and epithelial integrity, and spared cell death in crypt base columnar cells compared to TAI-CONV irradiation. Importantly, TAI-FLASH and TAI-CONV irradiation had similar efficacy in reducing tumor burden while improving intestinal function in a preclinical model of ovarian cancer metastasis. These findings suggest that FLASH irradiation may be an effective strategy to enhance the therapeutic index of abdominal radiotherapy, with potential application to metastatic ovarian cancer.

Introduction: Oligometastatic disease has emerged as an intermediate state between localized and systemic cancer. Improvements in diagnostic modalities such as functional imaging allow a greater frequency of oligometastases diagnosis. Patients with selected oligometastatic epithelial ovarian carcinoma (EOC) may be treated with metastasis-directed stereotactic body radiotherapy (SBRT) rather than chemotherapy., Case Description: We describe a 58-year-old woman who underwent surgery and chemotherapy for an EOC. The patient underwent 3 chemotherapy lines for recurrence of disease, but had allergic reactions and serious hematologic toxicity. During follow-up, lymph node oligometastases were diagnosed and treated with repeated SBRT because the patient refused further chemotherapy. No side effects were observed after each course of SBRT and the patient obtained complete response of all irradiated sites., Conclusions: SBRT is a promising treatment approach for recurrent oligometastatic EOC with a high control rate and irrelevant iatrogenic toxicity. The possibility to repeat SBRT courses when new oligometastases are encountered in other sites resulted in an adequate long-term palliation approach.

We aimed to provide evidence for radiotherapy treatment regimens in patients with clinically recurrent ovarian cancer. We analyzed the survival and prognostic factors in 43 patients who were treated for recurrent ovarian cancer at 58 tumor sites using three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) during January 2006-December 2017. t years 1, 2, and 3, overall survival (OS) rate was 82.4%, 68.4%, and 57.9%; local control (LC) rate was 100%, 100% and 80%; recurrence free survival (RFS) rate was 86.8%, 66.6%, and 61.1%; and disease-free survival (DFS) rate was 79.7%, 56.7%, and 46.8%, respectively. The radiotherapy technique was determined to be an independent prognostic factor for survival; the survival rate of patients was significantly improved with IMRT compared to 3D-CRT (P = 0.035). Radiotherapy dose was an independent prognostic factor; survival rate improved when patients were treated with a radiation dose ≥ 60 Gy as compared to < 60 Gy (P = 0.046). Elective nodal prophylactic radiation therapy (ENRT) did not lead to a significant improvement in survival when compared to involved-field radiation therapy (IFRT). The toxicities of 3D-CRT and IMRT were tolerable. One patient (2.3%) had grade 3 acute gastrointestinal (GI) toxicity, 2 (4.6%) grade 3 late GI toxicity, 5 (11.6%) grade 3 hematological toxicity, and 2 (4.6%) had grade 4 hematological toxicity. IMRT improved LC and OS in patients with recurrent ovarian cancer after surgery and multiple chemotherapy; toxicities were tolerable. The IMRT technique and radiotherapy dose of ≥ 60 Gy had independent prognostic significance for the survival of such patients.

Background: Adjuvant treatment in early ovarian clear cell carcinoma (OCCC) is not yet standardized. The objective of this population-based study was to compare the outcome of patients with early OCCC treated with adjuvant chemotherapy versus chemoradiotherapy (chemoRT) and evaluate the association of adjuvant radiotherapy regimens (whole abdominal radiotherapy [WART] versus pelvic nodal radiotherapy [PRT]) with outcome., Patients and Methods: Chart review was conducted to identify patients with stage I and II OCCC with complete information on staging. Patients with stage IA, IB, or IC OCCC purely resulting from capsular rupture were excluded because the provincial protocol does not recommend adjuvant treatment., Results: Overall, 403 patients were identified and 343 received adjuvant treatment, of whom 255 had stage IC or II OCCC and 153 were eligible for final analysis. On Cox multivariable regression, receipt of chemoRT (n=90) was associated with an improvement in failure-free survival (FFS) (hazard ratio [HR], 0.57; 95% CI, 0.34-0.94) compared with chemotherapy alone (n=63). Use of chemoRT also resulted in 54% reduction in the cumulative incidence of cancer-specific mortality (subdistribution HR, 0.46; 95% CI, 0.24-0.89). However, there was no significant difference in the HR for overall survival (OS) between the chemoRT (HR, 0.70; 95% CI, 0.43-1.13) and chemotherapy group. Relative to chemotherapy + WART (chemo-WART), chemotherapy + PRT (chemo-PRT) was not associated with any significant difference in HR for FFS (HR, 1.34; 95% CI, 0.40-4.44) or OS (HR, 1.13; 95% CI, 0.37-3.46)., Conclusions: Adjuvant chemoRT was associated with a lower risk of failure compared with chemotherapy alone. However, there was no difference in OS between the adjuvant chemotherapy and chemoRT regimens. Additionally, no significant difference in terms of FFS or OS was found between the chemo-WART and chemo-PRT groups.

Introduction: Data supporting stereotactic body radiotherapy for oligometastatic patients are increasing; however, the outcomes for gynecological cancer patients have yet to be fully explored. Our aim is to analyze the clinical outcomes of stereotactic body radiotherapy in the treatment of patients with recurrent or oligometastatic ovarian cancer or cervical cancer., Methods: The clinical data of 29 patients (35 lesions) with oligometastatic cervical cancer (21 patients, 72%) and ovarian carcinoma (8 patients, 28%) who were treated with stereotactic body radiotherapy for metastatic sites were retrospectively evaluated. All patients had <5 metastases at diagnosis or during progression, and were treated with stereotactic body radiotherapy for oligometastatic disease. Patients with ≥5 metastases or with brain metastases and those who underwent re-irradiation for primary site were excluded. Age, progression time, mean biologically effective dose, and treatment response were compared for overall survival and progression-free survival., Results: A total of 29 patients were included in the study. De novo oligometastatic disease was observed in 7 patients (24%), and 22 patients (76%) had oligoprogression. The median follow-up was 15.3 months (range 1.9-95.2). The 1 and 2 year overall survival rates were 85% and 62%, respectively, and the 1 and 2 year progression-free survival rates were 27% and 18%, respectively. The 1 and 2 year local control rates for all patients were 84% and 84%, respectively. All disease progressions were observed at a median time of 7.7 months (range 1.0-16.0) after the completion of stereotactic body radiotherapy. Patients with a complete response after stereotactic body radiotherapy for oligometastasis had a significantly higher 2 year overall survival and progression-free survival compared with their counterparts. In multivariate analysis, early progression (≤12 months) and complete response after stereotactic body radiotherapy for oligometastasis were the significant prognostic factors for improved overall survival. However, no significant factor was found for progression-free survival in the multivariable analysis. No patients experienced grade 3 or higher acute or late toxicities., Conclusions: Patients with early detection of oligometastasis (≤12 months) and with complete response observed at the stereotactic body radiotherapy site had a better survival compared with their counterparts. Stereotactic body radiotherapy at the oligometastatic site resulted in excellent local control rates with minimal toxicity, and can potentially contribute to long-term survival., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: This study evaluates the outcomes and toxicity of stereotactic body radiation therapy (SBRT) in ovarian cancer., Methods: This retrospective analysis considered all patients treated with SBRT from 2009 to 2018 with a primary ovarian tumor. Follow-up included PET-CT and CT scans at 2-3 month intervals. Statistical analysis primarily consisted of univariate analysis, Cox proportional hazards analysis, and the Kaplan-Meier method., Results: The study included 35 patients with 98 treatments for lymph nodes (51), local recurrence (21), and de novo solid metastases (26). Median biologically effective dose (BED), gross tumor volume, and planning target volume were 38.40 Gy, 10.41 cc, and 25.21 cc, respectively. 52 lesions showed complete radiographic response, and two-year local control was 80%. Median overall survival (OS) was 35.2 months, and two-year progression-free survival (PFS) was 12%. On univariate analysis, Eastern Cooperative Oncology Group performance status > 0 was predictive of decreased OS (p = 0.0024) and PFS (p = 0.044). Factors predictive of local failure included lower BED (p = 0.016), treatment for recurrence (p = 0.029), and higher pre-treatment SUV (p = 0.026). Kaplan-Meier analysis showed BED ≤35 Gy (p < 0.005) and treatment for recurrence (p = 0.01) to be predictive of local failure. On Cox proportional hazards analysis, treatment of lymph nodes was predictive of complete radiographic response (hazard ratio (HR) = 4.95), as was higher BED (HR = 1.03). Toxicity included 27 cases of grade < 3 toxicity, and one grade 5 late toxicity of GI bleed from a radiation therapy-induced duodenal ulcer., Conclusions: SBRT provides durable local control with minimal toxicity in ovarian cancer, especially with BED > 35 Gy and treatment for lymph nodes.

Ovarian cancer is the fifth most common cancer in women in France with 4714 new cases in 2017. More than 70% of patients whose disease is initially locally advanced will present locoregional or distant recurrence. Therapeutic options in this situation are not consensual. They are based on chemotherapy possibly associated with an iterative cytoreductive surgery when it is bearable by the patient. The place of radiotherapy in the management of the disease is hidden in the vast majority of national or international standards. We conducted a general review of the literature to clarify the role of irradiation in the global management of ovarian cancers, particularly in recurrence., (Copyright © 2020 Société française de radiothérapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.)

Background: Recent studies have reported improvement of outcomes (progression-free survival, overall survival, and prolongation of androgen deprivation treatment-free survival) with stereotactic body radiotherapy (SBRT) in non-small cell lung cancer and prostate cancer. The aim of this retrospective, multicenter study (MITO RT-01) was to define activity and safety of SBRT in a very large, real-world data set of patients with metastatic, persistent, and recurrent ovarian cancer (MPR-OC)., Materials and Methods: The endpoints of the study were the rate of complete response (CR) to SBRT and the 24-month actuarial local control (LC) rate on "per-lesion" basis. The secondary endpoints were acute and late toxicities and the 24-month actuarial late toxicity-free survival. Objective response rate (ORR) included CR and partial response (PR). Clinical benefit (CB) included ORR and stable disease (SD). Toxicity was evaluated by the Radiation Therapy Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC) and Common Terminology Criteria for Adverse Events (CTCAE) scales, according to center policy. Logistic and Cox regression were used for the uni- and multivariate analysis of factors predicting clinical CR and actuarial outcomes., Results: CR, PR, and SD were observed in 291 (65.2%), 106 (23.8%), and 33 (7.4%) lesions, giving a rate of CB of 96.4%. Patient aged ≤60 years, planning target volume (PTV) ≤18 cm 3 , lymph node disease, and biologically effective dose α/β10 > 70 Gy were associated with higher chance of CR in the multivariate analysis. With a median follow-up of 22 months (range, 3-120), the 24-month actuarial LC rate was 81.9%. Achievement of CR and total dose >25 Gy were associated with better LC rate in the multivariate analysis. Mild toxicity was experienced in 54 (20.7%) patients; of 63 side effects, 48 were grade 1, and 15 were grade 2. The 24-month late toxicity-free survival rate was 95.1%., Conclusions: This study confirms the activity and safety of SBRT in patients with MPR-OC and identifies clinical and treatment parameters able to predict CR and LC rate., Implications for Practice: This study aimed to define activity and safety of stereotactic body radiotherapy (SBRT) in a very large, real life data set of patients with metastatic, persistent, recurrent ovarian cancer (MPR-OC). Patient age <60 years, PTV <18 cm 3 , lymph node disease, and biologically effective dose α/β10 >70 Gy were associated with higher chance of complete response (CR). Achievement of CR and total dose >25 Gy were associated with better local control (LC) rate. Mild toxicity was experienced in 20.7% of patients. In conclusion, this study confirms the activity and safety of SBRT in MPR-OC patients and identifies clinical and treatment parameters able to predict CR and LC rate., (© AlphaMed Press 2019.)

Objectives: In patients with advanced ovarian, fallopian and primary peritoneal carcinoma, complete interval debulking surgery (IDS) is often performed after neoadjuvant chemotherapy (NAC) to achieve long progression-free survival (PFS) and overall survival (OS). We aimed to investigate the utility of 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) PET/CT in patients with these malignancies who underwent complete IDS., Methods: Between 2009 and 2017, twenty-two patients underwent FDG PET/CT scans before and after NAC. The highest SUVmax/peak (standardized uptake value), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for whole lesions were defined as target SUVmax/peak, tMTV and tTLG, respectively. We also calculated these reduction rates during NAC. These parameters were compared between the groups with platinum-free interval (PFI) > 12 months (n = 10) and those with PFI ≤ 12 months (n = 12). The PFS and OS were evaluated using these quantitative parameters, and in terms of the presence of visually detectable residual lesions after NAC., Results: The target SUVmax/peak before NAC, the reduction rates in the target SUVmax, tMTV and tTLG were significantly higher in the group with PFI > 12 months than the shorter PFI group (p < 0.05). Especially in PFS, the higher reduction rates in the target SUVmax/peak, tMTV, and tTLG had an excellent prognostic stratification (p < 0.05) and the FDG visually negative group after NAC had a significantly better prognosis than the other group (p < 0.01)., Conclusions: The reduction rate of FDG PET-based quantitative values and visual analysis after NAC demonstrated prognostic potential, especially in PFS.

Objective: To establish the technique of intratumoral combination therapy of radiofrequency hyperthermia (RFH) with herpes simplex virus-thymidine kinase/ganciclovir (HSV-TK/GCV) gene therapy for rat ovarian cancers. Material and methods: This study consisted of three parts: (1) in vitro experiments to establish the 'proof of principal' that combination of RFH and HSV-TK gene therapy has the synergistic effect on human ovarian cancer cells; (2) creation of bioluminescence imaging-detectable rat ovarian cancer model; and (3) in vivo experiments using this rat model to validate the technical feasibility of the combination therapy. Cells and nude rats were divided into four groups: (i) combination therapy (HSV-TK/GCV + RFH); (ii) RFH; (iii) HSV-TK/GCV; and (iv) phosphate-buffered saline (PBS). Data were analyzed using Dunnett t -test or Kruskal-Wallis test. Results: Cell proliferation assay demonstrated significantly greater reduction in viable cells with the combination therapy [0.52 (0.43, 0.61)] compared to other treatments [RFH 0.90 (0.84, 0.96), HSV-TK/GCV 0.71 (0.53, 0.88), PBS 1 (1, 1); p  < .05]. For 24 rat models with bioluminescence imaging-detectable orthotopic ovarian cancer ( n  = 6 per group), optical imaging demonstrated significantly decreased relative bioluminescence signal with the combination therapy [0.81 (0.52, 1.08)] compared to other treatments [RFH 3.60 (2.34, 4.86), HSV-TK/GCV 2.21 (1.71, 2.71), PBS 3.74 (3.19, 4.29); p  < .001]. Ultrasound imaging demonstrated the smallest relative tumor volume with the combination therapy [0.78 (0.45, 1.11) versus 3.50 (2.67, 4.33), 2.10 (0.83, 3.37), 3.70 (1.79, 5.61); p  < .05]. Conclusion: The feasibility of intratumoral RFH-enhanced HSV-TK/GCV gene therapy was established on a unique rat model with molecular imaging-detectable orthotopic ovarian cancer.

Ovarian cancer relapses have been traditionally classified according to the platinum-free interval, leading to an arbitrary categorization of possible scenarios and treatment options. Its relevance in assessing treatment strategies has been revised in the last several years, as the panorama is constantly changing in the era of personalized medicine and targeted therapies. Factors to be considered while defining the best management of recurrent disease, and, consequently, the available treatment alternatives are increasing. Platinum remains one of the milestones of ovarian cancer treatment, but for some patients it might not be an ideal choice for several reasons other than limited platinum sensitivity. This review aims to analyze the scenarios in which platinum is not considered suitable in the management of patients with recurrent ovarian cancer, and the currently available alternatives., Competing Interests: Competing interests: AB and GM report personal fees and non-financial support from Tesaro, AstraZeneca, Pharmamar and Roche, outside the submitted work; LB reports personal fees and non-financial support from Tesaro, AstraZeneca, and Pharmamar outside the submitted work., (© IGCS and ESGO 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: To assess late toxicity, quality of life and oncological outcome after consolidative whole abdominal radiotherapy (WART) following cytoreductive surgery and carboplatin/paclitaxel chemotherapy in high risk patients with advanced ovarian cancer FIGO stage III using IMRT (Intensity modulated radiation therapy)., Methods: The OVAR-IMRT-02 study is a multi-center single-arm phase-II-trial. Twenty patients with optimally debulked ovarian cancer stage FIGO III with complete remission after chemotherapy were treated with intensity modulated WART. A total dose of 30 Gy in 20 fractions was applied to the entire peritoneal cavity. Primary endpoint was treatment tolerability; secondary objectives were acute and chronic toxicities, quality of life, rates of therapy disruption/abortion, progression-free survival (PFS) and overall survival (OS)., Results: All patients completed treatment and 10/20 patients (50%) reached the final study follow-up of 36 months. Late side effects consisted of °1-°2 lower limb edema (44.5%), with one patient (5.6%) showing °3 edema. Three patients (16.7%) showed elevated gamma-Glutamyltransferase. There were no severe late side effects regarding renal or hepatic function or any gastrointestinal toxicity greater than °2. During WART, mean global health status decreased by 18.1 points (95%-CI: 7.1-29.0), but completely normalized after 6 months. The same trend was observed for the function scale scores. Kaplan-Meier-estimated 1-, 2- and 3-year PFS was 74, 51 and 40%, respectively. 1-, 2- and 3-year OS was 89, 83 and 83%, respectively., Conclusions: Intensity modulated WART after aggressive surgery and carboplatin/paclitaxel chemotherapy is associated with an acceptable risk of acute and late toxicity and minor impact on long-term quality of life. Together with the promising results for PFS and OS, intensity modulated WART could offer a new therapeutic option for consolidation treatment of patients with advanced ovarian cancer., Trial Registration: The study is registered with ClinicalTrials.gov ( NCT01180504 ). Registered 12 August 2010 - retrospectively registered.

Synchrotron generated monochromatic X-rays can be precisely tuned to the K-shell energy of high Z materials resulting in the release of the Auger electrons. In this work, we have employed this mechanism to destruct tumor spheroids. We first loaded gadolinium onto the surface of mesoporous silica nanoparticles (MSNs) producing gadolinium-loaded MSN (Gd-MSN). When Gd-MSN was added to the tumor spheroids, we observed efficient uptake and uniform distribution of Gd-MSN. Gd-MSN also can be taken up into cancer cells and localize to a site just outside of the cell nucleus. Exposure of the Gd-MSN containing tumor spheroids to monochromatic X-ray beams resulted in almost complete destruction. Importantly, this effect was observed at an energy level of 50.25 keV, but not with 50.0 keV. These results suggest that it is possible to use precisely tuned monochromatic X-rays to destruct tumor mass loaded with high Z materials, while sparing other cells. Our experiments point to the importance of nanoparticles to facilitate loading of gadolinium to tumor spheroids and to localize at a site close to the nucleus. Because the nanoparticles can target to tumor, our study opens up the possibility of developing a new type of radiation therapy for cancer.

Objectives: In our institutional experience, involved-field radiation therapy (IFRT) yields favorable outcomes in patients with recurrent epithelial ovarian cancer (EOC). This retrospective study aimed to investigate the clinical benefits of IFRT in this patient population., Methods: Among patients treated with IFRT for recurrent EOC between 2010 and 2017, 61 patients with 90 treatments were included. IFRT encompassed all treatable lesions identified via imaging studies with 10-15-mm margins. Prescribed doses were ≥45 Gy (equivalent dose in 2 Gy/fraction)., Results: Patients were followed up for a median of 19.0 (Interquartile range, 8.6-34.9) months after IFRT. The 2-year in-field control, progression-free survival, and overall survival (OS) rates were 42.7%, 24.2%, and 78.9%, respectively. Fifty-three IFRT sessions (58.9%) were followed by systemic chemotherapy, and the median chemotherapy-free interval (CFI) was 10.5 (95% confidence interval=7.3-13.7) months. A higher carbohydrate antigen-125 (CA-125) level correlated with a worse 2-year OS (69.2% vs. 91.0%; p=0.001) and shorter median CFI (4.7 vs. 11.9 months; p<0.001). Twenty-eight (31.1%) of 90 treatments yielded a long-term CFI >12 months. For patients with a normal CA-125 level and/or platinum-sensitive tumor, IFRT prolonged CFI regardless of pre-existing carcinomatosis, gross tumor volume, and number of treatment sites., Conclusion: Our early experience demonstrates the safety and feasibility of IFRT as an effective salvage therapy and enables a "chemotherapy holiday" in selected recurrent EOC settings. The CA-125 value before IFRT (within normal range) and/or platinum sensitivity could be used as selection criteria for IFRT., Competing Interests: No potential conflict of interest relevant to this article was reported., (Copyright © 2019. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology.)

The use of nanobodies (Nbs) as vehicles in targeted alpha therapy (TAT) has gained great interest because of their excellent properties. They combine high in vivo affinity and specificity of binding with fast kinetics. This research investigates a novel targeted therapy that combines the α-particle emitter astatine-211 ( 211 At) and the anti-HER2 Nb 2Rs15d to selectively target HER2+ cancer cells. Two distinctive radiochemical methodologies are investigated using three different coupling reagents. The first method uses the coupling reagents, N -succinimidyl 4-(1,2-bis- tert -butoxycarbonyl)guanidinomethyl-3-(trimethylstannyl)benzoate (Boc 2 -SGMTB) and N -succinimidyl-3-(trimethylstannyl)benzoate ( m -MeATE), which are both directed to amino groups on the Nb, resulting in random conjugation. The second method aims at obtaining a homogeneous tracer population, via a site-specific conjugation of the N -[2-(maleimido)ethyl]-3-(trimethylstannyl)benzamide (MSB) reagent onto the carboxyl-terminal cysteine of the Nb. The resulting radioconjugates are evaluated in vitro and in vivo. 2Rs15d is labeled with 211 At using Boc 2 -SGMTB, m -MeATE, and MSB. After astatination and purification, the binding specificity of the radioconjugates is validated on HER2+ cells, followed by an in vivo biodistribution assessment in SKOV-3 xenografted mice. α-camera imaging is performed to determine uptake and activity distribution in kidneys/tumors. 2Rs15d astatination resulted in a high radiochemical purity >95% for all radioconjugates. The biodistribution studies of all radioconjugates revealed comparable tumor uptake (higher than 8% ID/g at 1 h). [ 211 At]SAGMB-2Rs15d showed minor uptake in normal tissues. Only in the kidneys, a higher uptake was measured after 1 h, but decreased rapidly after 3 h. Astatinated Nbs consisting of m -MeATE or MSB reagents revealed elevated uptake in lungs and stomach, indicating the presence of released 211 At. α-Camera imaging of tumors revealed a homogeneous activity distribution. The radioactivity in the kidneys was initially concentrated in the renal cortex, while after 3 h most radioactivity was measured in the medulla, confirming the fast washout into urine. Changing the reagents for Nb astatination resulted in different in vivo biodistribution profiles, while keeping the targeting moiety identical. Boc 2 -SGMTB is the preferred reagent for Nb astatination because of its high tumor uptake, its low background signals, and its fast renal excretion. We envision [ 211 At]SAGMB-2Rs15d to be a promising therapeutic agent for TAT and aim toward efficacy evaluation.

Eliminating microscopic residual disease with α-particle radiation is theoretically appealing. After extensive preclinical work with α-particle-emitting 211 At, we performed a phase I trial with intraperitoneal α-particle therapy in epithelial ovarian cancer using 211 At conjugated to MX35, the antigen-binding fragments-F(ab') 2 -of a mouse monoclonal antibody. We now present clinical outcome data and toxicity in a long-term follow-up with individual absorbed dose estimations. Methods: Twelve patients with relapsed epithelial ovarian cancer, achieving a second complete or nearly complete response with chemotherapy, received intraperitoneal treatment with escalating (20-215 MBq/L) activity concentrations of 211 At-MX35 F(ab') 2. Results: The activity concentration was escalated to 215 MBq/L without any dose-limiting toxicities. Most toxicities were low-grade and likely related to the treatment procedure, not clearly linked to the α-particle irradiation, with no observed hematologic toxicity. One grade 3 fatigue and 1 grade 4 intestinal perforation during catheter implantation were observed. Four patients had a survival of more than 6 y, one of whom did not relapse. At progression, chemotherapy was given without signs of reduced tolerability. Overall median survival was 35 mo, with a 1-, 2-, 5-, and 10-y survival of 100%, 83%, 50%, and 25%, respectively. Calculations of the absorbed doses showed that a lower specific activity is associated with a lower single-cell dose, whereas a high specific activity may result in a lower central dose in microtumors. Individual differences in absorbed dose to possible microtumors were due to variations in administered activity and the specific activity. Conclusion : No apparent signs of radiation-induced toxicity or decreased tolerance to relapse therapy were observed. The dosimetric calculations show that further optimization is advisable to increase the efficacy and reduce possible long-term toxicity., (© 2019 by the Society of Nuclear Medicine and Molecular Imaging.)