Search

Introduction: Gross hematuria (GH) in advanced/inoperable bladder cancer patients causes significant morbidity. Patients frequently need multiple transfusions. Hypofractionated radiotherapy (RT) has been shown to be effective in symptom palliation. In this study, we explore the efficacy of various fractionation regimens in these patients. Methods: This single institute retrospective analysis was conducted on 60 consecutive patients treated with palliative RT. Fractionation (single versus multiple) and biologically equivalent doses (BED; high ≥36 Gy versus low <36 Gy) were used to compare the efficacy of various fractionation regimens. The primary outcome was the difference in objective response rate (ORR) between various strata at 2, 4, 8 and 12 weeks. Major secondary outcomes were differences in ORR according to Eastern Cooperative Oncology Group (ECOG) performance status (PS) and tumour node metastases (TNM) stage, and the proportion of patients requiring re-transfusion(s) at 12 weeks. Data were analysed using SPSS 23. Results: Overall ORR at 2, 4, 8 and 12 weeks was 86%, 77%, 67% and 55%, respectively. There was no statistically significant difference in response rates between single or multifraction, or high versus low BED groups (All p = >0.05). Moreover, ECOG PS (p = 0.11) or TNM stage (p = 0.58) also had no impact on the response rate at 12 weeks. Nearly onethird (31%) of patients required further transfusions at 12 weeks. Conclusion: RT is an effective modality to control GH. No difference in ORR was found between single fractions versus multiple fractions, or high versus low BED regimens. Single fraction RT can be offered to these patients considering low cost, patient convenience and minimal side effects. [ABSTRACT FROM AUTHOR]

Background: To assess the effectiveness of a single fraction dose of radiotherapy (6.25Gy versus 8 Gy) with zoledronic acid in cancer patients with painful bone metastases in treating pain; quality of life; duration of pain response and incidence of skeletal related events (SREs). Material and methods: A total of 80 patients with bone metastases presented in the department of Radiation Oncology, S.M.S hospital were randomly assigned to: Group A, received single dose of 6.25Gy with Zoledronic acid 4mg and Group B, received single dose of 8Gy with Zoledronic acid 4mg. The main variable was pain which was assessed with 11 point Numeric pain Rating Score (NRS). Results: There were total 80 patients, 40 in each group, with mean age 54.6 years and 54.5 years in group A and B respectively. Most frequent primary malignant sites were lung (36.2%), breast (28.7%), and prostate (8.7%). At 4 weeks post radiotherapy, complete response was 25% in group A, 27.5% in group B and overall response was 82.5% in group A, 85% in group B. At 2 months post radiotherapy complete response was observed in 25% of patients in group A, while 30% in group B and overall response in 85 % in group A and 87.5% in group B. Quality of life improved in both groups. Mean duration of pain relief was 13.5 weeks vs. 14.5 weeks respectively in group A and group B. Conclusion: There was improvement in pain relief and quality of life post radiotherapy in both the groups. On comparison between 2 groups, the overall pain relief was insignificant between the two dose schedules. So a lower dose 6.25Gy is almost as effective as 8 Gy single fractions for treatment of painful bone metastases. [ABSTRACT FROM AUTHOR]

To present the outcome and toxicity results of a prospective trial of 21 Gy single fraction high-dose-rate (HDR) brachytherapy for men with low- or intermediate-risk prostate cancer. Patients were treated according to an IRB-approved prospective study of single fraction HDR brachytherapy. Eligible patients had low- or intermediate-risk prostate cancer with tumor stage ≤ T2b, PSA ≤ 15, and Gleason score ≤ 7. Patients underwent trans-rectal ultrasound-guided trans-perineal implant of the prostate followed by single fraction HDR brachytherapy to a dose of 21 Gy. The primary endpoint was grade ≥ 2 urinary/GI toxicity rates. Twenty-six patients were enrolled with a median follow up of 5.1 years and median age of 64 years. 88.5% of patients had T1 disease, 15.4% had Gleason score 6 (84.6% Gleason 7), and median pre-treatment PSA was 5.0 ng/mL. Acute and chronic grade ≥ 2 urinary toxicity rates were 38.5% and 38.5%, respectively. There were no grade ≥ 2 acute or chronic GI toxicities. Six (23.1%) patients experienced biochemical failure, six (23.1%) patients experienced radiographic local failure, and five (19.2%) patients had biopsy-proven local failure. No patients developed regional lymph node recurrence or distant metastasis. 5-year overall survival and cause-specific survival were 96.2% and 100%, respectively. 21 Gy single fraction HDR brachytherapy was associated with modestly higher-than-anticipated chronic urinary toxicity, as well as high biochemical and local failure rates. The results from this prospective pilot study do not support the use of this regimen in standard clinical practice. [ABSTRACT FROM AUTHOR]

The effectiveness of single-fraction 8-Gy radiotherapy for painful bone metastases has been verified in numerous randomized controlled trials. However, few reports have described the effectiveness of single-fraction 8-Gy radiotherapy in painful tumors other than bone metastases. We conducted a retrospective analysis to evaluate the pain response to single-fraction 8-Gy radiotherapy in painful non-bone-metastasis tumors. We included patients who had received single-fraction 8-Gy radiotherapy for such tumors between January 2017 and December 2022, excluding those with brain metastases, hematological tumors and those who received re-irradiation. Pain response assessment was based on the best responses documented in the medical records and conducted by two radiation oncologists. A total of 36 eligible patients were included in this study. The irradiation sites included primary lesions in eight patients, lymph node metastases in eight, muscle metastases in seven, pleural dissemination in four, skin/subcutaneous metastases in four and other sites in five. Pain response was assessed in 24 patients after radiotherapy. Pain response rate was 88% in evaluable patients; 21 of the 24 patients experienced response. The median assessment date for pain response was 37 days (range: 8–156 days) after radiotherapy. Re-irradiation was performed in four patients (11%). Single-fraction 8-Gy radiotherapy seemed to be a promising treatment option for painful non-bone-metastasis tumors and warrants further investigation. [ABSTRACT FROM AUTHOR]

Abstract Background Radiotherapy delivery regimens can vary between a single fraction (SF) and multiple fractions (MF) given daily for up to several weeks depending on the location of the cancer or metastases. With limited evidence comparing fractionation regimens for oligometastases, there is support to explore toxicity levels to nearby organs at risk as a primary outcome while using SF and MF stereotactic ablative radiotherapy (SABR) as well as explore differences in patient-reported quality of life and experience. Methods This study will randomize 598 patients in a 1:1 ratio between the standard arm (MF SABR) and the experimental arm (SF SABR). This trial is designed as two randomized controlled trials within one patient population for resource efficiency. The primary objective of the first randomization is to determine if SF SABR is non-inferior to MF SABR, with respect to healthcare provider (HCP)-reported grade 3-5 adverse events (AEs) that are related to SABR. Primary endpoint is toxicity while secondary endpoints include lesional control rate (LCR), and progression-free survival (PFS). The second randomization (BC Cancer sites only) will allocate participants to either complete quality of life (QoL) questionnaires only; or QoL questionnaires and a symptom-specific survey with symptom-guided HCP intervention. The primary objective of the second randomization is to determine if radiation-related symptom questionnaire-guided HCP intervention results in improved reported QoL as measured by the EuroQoL-5-dimensions-5levels (EQ-5D-5L) instrument. The primary endpoint is patient-reported QoL and secondary endpoints include: persistence/resolution of symptom reporting, QoL, intervention cost effectiveness, resource utilization, and overall survival. Discussion This study will compare SF and MF SABR in the treatment of oligometastases and oligoprogression to determine if there is non-inferior toxicity for SF SABR in selected participants with 1-5 oligometastatic lesions. This study will also compare patient-reported QoL between participants who receive radiation-related symptom-guided HCP intervention and those who complete questionnaires alone. Trial registration Clinicaltrials.gov identifier: NCT05784428. Date of Registration: 23 March 2023.

Achieving esthetically pleasing results for helical keloids can be challenging. This study aims to share the results of a treatment approach for helical keloids, which involves complete excision and reconstruction using an omega variant keystone flap, followed by a single fractional radiotherapy. The current study is a retrospective review of 25 helical keloids in 21 patients from May 2021 to March 2023. All keloid cases were excised entirely. We covered the defect with an omega variant keystone flap followed by a single fraction of 9.5 or 10 Gy radiotherapy within 24 h after surgery. The mean follow-up period was 12 months. The primary outcome was recorded as recurrence versus non-recurrence. The secondary outcome was scores assessed by the Patient and Observer Scar Assessment Scale. All 25 keloids in 21 patients completed the treatment protocol, with a follow-up interval of 12 months. Of these patients, 100% had successful treatment of their keloids without any keloid recurrence. The postoperative course was uneventful except for one case of early postoperative flap congestion, which was spontaneously healed without any interventions. Scores obtained from the Patient and Observer Scar Assessment Scale showed that pain, itchiness, color, stiffness, thickness, irregularity, vascularity, pigmentation, thickness, relief, and pliability significantly improved. (p < 0.001). We successfully reconstructed helical keloids using an omega variant keystone flap after keloid removal followed by 9.5 or 10 Gy single fractional radiotherapy without any keloid recurrence in one-year follow-ups. [ABSTRACT FROM AUTHOR]

Background: Radiotherapy delivery regimens can vary between a single fraction (SF) and multiple fractions (MF) given daily for up to several weeks depending on the location of the cancer or metastases. With limited evidence comparing fractionation regimens for oligometastases, there is support to explore toxicity levels to nearby organs at risk as a primary outcome while using SF and MF stereotactic ablative radiotherapy (SABR) as well as explore differences in patient-reported quality of life and experience. Methods: This study will randomize 598 patients in a 1:1 ratio between the standard arm (MF SABR) and the experimental arm (SF SABR). This trial is designed as two randomized controlled trials within one patient population for resource efficiency. The primary objective of the first randomization is to determine if SF SABR is non-inferior to MF SABR, with respect to healthcare provider (HCP)-reported grade 3-5 adverse events (AEs) that are related to SABR. Primary endpoint is toxicity while secondary endpoints include lesional control rate (LCR), and progression-free survival (PFS). The second randomization (BC Cancer sites only) will allocate participants to either complete quality of life (QoL) questionnaires only; or QoL questionnaires and a symptom-specific survey with symptom-guided HCP intervention. The primary objective of the second randomization is to determine if radiation-related symptom questionnaire-guided HCP intervention results in improved reported QoL as measured by the EuroQoL-5-dimensions-5levels (EQ-5D-5L) instrument. The primary endpoint is patient-reported QoL and secondary endpoints include: persistence/resolution of symptom reporting, QoL, intervention cost effectiveness, resource utilization, and overall survival. Discussion: This study will compare SF and MF SABR in the treatment of oligometastases and oligoprogression to determine if there is non-inferior toxicity for SF SABR in selected participants with 1-5 oligometastatic lesions. This study will also compare patient-reported QoL between participants who receive radiation-related symptom-guided HCP intervention and those who complete questionnaires alone. Trial registration: Clinicaltrials.gov identifier: NCT05784428. Date of Registration: 23 March 2023. [ABSTRACT FROM AUTHOR]

Stereotactic ablative body radiotherapy (SABR) consists of delivering high doses of ionising radiation, typically across three to eight fractions with high precision and conformity. SABR has become increasingly commonplace throughout the last quarter of a century and is offered for the treatment of various primary and metastatic tumour types. Delivering SABR in a single fraction has arisen as an appealing possibility for several reasons. These include fewer hospital visits, greater patient convenience, improved sustainability and lower costs. However, these factors must be balanced against considerations such as toxicity, side-effects and, most importantly, progression-free and overall survival. In this review we seek to analyse the results of studies looking at the efficacy of single-fraction SABR for lung, prostate, renal and pancreas primary tumours, as well as oligometastases. The tumour type to be most widely treated with single-fraction SABR is lung, but its remit continues to expand. We also look at the biological rationale underpinning SABR and how this can be extended to single-fraction regimens. Finally, we turn our attention towards the future directions of SABR and specifically single-fraction regimens. These include the possibility of combining SABR with immunotherapy and technological advances in the field, which could serve to expand the scope of SABR. We conclude by summarising the current clinical studies of single-fraction SABR. [ABSTRACT FROM AUTHOR]

For low-risk breast cancer, accelerated partial breast irradiation (APBI) is a level 1 evidence procedure. Brachytherapy based very APBI (vAPBI) makes it possible to perform adjuvant irradiation in 4 to 1 fraction. However, vAPBI organization is critical. The aim of this technical note is to report on its optimization. To offer to low-risk breast cancer patient an efficient, simple, rapid adjuvant irradiation with a reduced number of hospital visits, a new organization of vAPBI based on a single fraction was established, merging all the different steps (from first consultation to irradiation) into a 4–5-consecutive-hour period. This therapeutic program was developed in strong collaboration with radiation oncologists, medical physicists, radiation therapists, and the medical secretary. After the validation of adjuvant breast irradiation, the patient was offered a telemedicine consultation with the radiation oncologist. Then, the day of vAPBI, the patient arrived at the brachytherapy unit at 08:00 AM for an in-person consultation followed by a preimplant CT scan (defining catheter number and position). After breast local anesthesia, catheter placement was performed followed by a postimplant CT scan for planning purposes. A total dose of 16 Gy in 1 fraction was delivered before removing the catheters. The patient was discharged from the brachytherapy unit around 12:30 PM with an upcoming surveillance consultation date. VAPBI organization optimization makes it possible to propose a short 5-h procedure from medical consultation to treatment with only one round trip. Strict organization among staff is required. [ABSTRACT FROM AUTHOR]

Purpose: To report the results of the Single Fraction Early Prostate Irradiation (SiFEPI) phase 2 prospective trial. Materials/Methods: The SiFEPI trial (NCT02104362) evaluated a single fraction of high-dose rate brachytherapy (HDB) for low- (LR) and favorable-intermediate (FIR) risk prostate cancers. After rectal spacer placement, a single fraction of 20 Gy was delivered to the prostate. Oncological outcome (biochemical (bRFS) and local (lRFS) relapses, disease-free (DFS) and overall (OS) survivals and toxicity (acute/late genito-urinary (GU), gastro-intestinal (GI) and sexual (S) toxicities were investigated. Results: From 03/2014 to 10/2017, 35 pts were enrolled, of whom 33 were evaluable. With a median age of 66 y [46–79], 25 (76 %) and 8 (24 %) pts were LR and FIR respectively. With a MFU of 72.8 months [64–86], 6y-bRFS, lRFS and mRFS were 62 % [45–85], 61 % [44–85] and 93 % [85–100] respectively while 6y-DFS, CSS and OS were 54 % [37–77], 100 % and 89 % [77–100] respectively. Late GU, GI and S toxicities were observed in 11 pts (33 %;18G1), 4 pts (12 %;4G1) and 7 pts (21 %;1G1,5G2,1G3) respectively. Biochemical relapse (BR) was observed in 11 pts (33 %;7LR,4FIR) with a median time interval between HDB and BR of 51 months [24–69]. Nine of these pts (82 %) presented a histologically proven isolated local recurrence. Conclusions: Long-term results of the SiFEPI trial show that a single fraction of 20 Gy leads to sub-optimal biochemical control for LR/FIR prostate cancers. The late GU and GI toxicity profile is encouraging, leading to consideration of HDB as a safe irradiation technique.

Background and Purpose: Magnetic resonance-guided radiotherapy (MRgRT) with real-time intra-fraction tumor motion monitoring allows for high precision Stereotactic Ablative Radiotherapy (SABR). This study aimed to investigate the clinical feasibility, patient satisfaction and delivery accuracy of single-fraction MR-guided SABR in a single day (one-stop-shop, OSS). Methods and Materials: Ten patients with small lung tumors eligible for single fraction treatments were included. The OSS procedure consisted of consultation, treatment simulation, treatment planning and delivery. Following SABR delivery, patients completed a reported experience measure (PREM) questionnaire. Prescribed doses ranged 28–34 Gy. Median GTV was 2.2 cm3 (range 1.3–22.9 cm3). A gating boundary of 3 mm, and PTV margin of 5 mm around the GTV, were used with auto-beam delivery control. Accuracy of SABR delivery was studied by analyzing delivered MR-cines reconstructed from machine log files. Results: All 10 patients completed the OSS procedure in a single day, and all reported satisfaction with the process. Median time for the treatment planning step and the whole procedure were 2.8 h and 6.6 h, respectively. With optimization of the procedure, treatment could be completed in half a day. During beam-on, the 3 mm tracking boundary encompassed between 78.0 and 100 % of the GTV across all patients, with corresponding PTV values being 94.4–100 % (5th-95th percentiles). On average, system-latency for triggering a beam-off event comprised 5.3 % of the delivery time. Latency reduced GTV coverage by an average of −0.3 %. Duty-cycles during treatment delivery ranged from 26.1 to 64.7 %. Conclusions: An OSS procedure with MR-guided SABR for lung cancer led to good patient satisfaction. Gated treatment delivery was highly accurate with little impact of system-latency.

Simple Summary: Patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT) often receive different treatment regimens based on the location of the tumor to minimize the risk of severe side effects. The aim of our study was to examine survival outcomes of patients treated with single-fraction SBRT for peripheral tumors and five-fraction SBRT for central tumors. In a cohort of 265 patients with NSCLC, we found no differences in patients treated for peripheral versus central tumors in progression-free survival, overall survival, local failure, nodal failure, or distant failure. These findings were confirmed upon propensity score matching. Our study demonstrated survival outcomes of patients treated with SBRT for early-stage NSCLC were equivalent for central and peripheral tumors. Background: The treatment of early-stage non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT) frequently involves different fractionation schemes for peripheral and central tumors due to concerns with toxicity. We performed an observational cohort study to determine survival outcomes for patients with peripheral and central NSCLC treated with SBRT. Methods: A single-institutional database of patients with early-stage NSCLC treated with SBRT from September 2008 to December 2018 was evaluated. Outcomes were progression-free survival (PFS), overall survival (OS), local failure (LF), nodal failure (NF), and distant failure (DF). Cox multivariable analysis (MVA), Kaplan–Meier plotting, Fine–Gray competing risk MVA, and propensity score matching were performed. Results: A total of 265 patients were included with a median follow-up of 44.2 months. There were 191 (72%) and 74 (28%) patients with peripheral and central tumors treated with single-fraction SBRT to a dose of 27 Gy and five-fraction SBRT to a dose of 50 Gy, respectively. On Cox MVA, there was no difference in OS (adjusted hazards ratio (aHR) of 1.04, 95% CI of 0.74–1.46) or PFS (aHR of 1.05, 95% CI of 0.76–1.45). On Fine–Gray competing risk MVA, there were no differences in LF, NF, or DF. Propensity matching confirmed these findings. Conclusion: The survival outcomes of patients treated with SBRT for early-stage NSCLC were equivalent for central and peripheral tumors. [ABSTRACT FROM AUTHOR]

This study aims to assess efficacy of a 15-Gy margin dose in terms with the hypothesis that efficacy will be comparable with historical controls with fewer radiation-related side effects. Patients who received single-fraction stereotactic radiosurgery (SRS) for metastatic brain tumors (prescribed 1500 cGy with 2-mm planning tumor volume) at the University of Missouri Hospital between 2004 and 2018 with at least 3 months of follow-up were retrospectively reviewed. Demographics, lesion dimensions, concurrent therapy, and treatment history before SRS were assessed. Outcomes included local control, distant control, radiation-related changes, survival, repeat SRS or whole-brain radiation therapy, and side effects. Data from the literature were pooled for a meta-analysis. A total of 142 patients had at least 3 months of follow-up data available. The 12-month actual local control rate among these patients was 92% per tumor. The overall intracranial control rate was 66.9% per patient. Radiation-related side effects occurred in 32.4% of patients (n = 46), with some patients having more than 1 side effect. Radiation-related radiographic changes occurred in 48 lesions (10.6%) in 37 patients (26%). Pathologically confirmed radiation necrosis occurred in 19 lesions (4%) and in 18 patients (12.6%). Local and distant control rates for this population was comparable with historical controls. Side effects in the literature are inconsistently reported, so rigorous comparative analysis is not possible. A single-fraction radiosurgery margin dose of 15 Gy to the planning tumor volume can effectively provide local control and distant control and is comparable with historical controls, which use 18–25 Gy, with a good toxicity profile. [ABSTRACT FROM AUTHOR]

• Doses exceeding 30 Gy in rats and 50 Gy in mice result in radionecrosis, with higher doses yielding earlier onset. • Larger irradiated volumes are associated with increased probability of radionecrosis. • Fractionation schedules fail to prevent radionecrosis even with a sub-necrotic single-fraction equivalent dose. • White matter, the hippocampus, and the subventricular zone are highly sensitive to irradiation. • More evolved mammals, BALB/c mice, and younger animals are more prone to radiation injury, whereas sex appears irrelevant. Radionecrosis is a common complication in radiation oncology, while mechanisms and risk factors have yet to be fully explored. We therefore conducted a systematic review to understand the pathogenesis and identify factors that significantly affect the development. We performed a systematic literature search based on the PRISMA guidelines using PubMed, Ovid, and Web of Science databases. The complete search strategy can be found as a preregistered protocol on PROSPERO (CRD42023361662). We included 83 studies, most involving healthy animals (n = 72, 86.75 %). High doses of hemispherical irradiation of 30 Gy in rats and 50 Gy in mice led repeatedly to radionecrosis among different studies and set-ups. Higher dose and larger irradiated volume were associated with earlier onset. Fractionated schedules showed limited effectiveness in the prevention of radionecrosis. Distinct anatomical brain structures respond to irradiation in various ways. White matter appears to be more vulnerable than gray matter. Younger age, more evolved animal species, and genetic background were also significant factors, whereas sex was irrelevant. Only 13.25 % of the studies were performed on primary brain tumor bearing animals, no studies on brain metastases are currently available. This systematic review identified various factors that significantly affect the induction of radionecrosis. The current state of research neglects the utilization of animal models of brain tumors, even though patients with brain malignancies constitute the largest group receiving brain irradiation. This latter aspect should be primarily addressed when developing an experimental radionecrosis model for translational implementation. [ABSTRACT FROM AUTHOR]

• Single-fraction SABR offers high local control and low toxicity in inoperable stage I lung cancer and lung oligometastases. • Excess toxicity with central lung lesions has been reported. • Proximity to brachial plexus and chest wall are not relative contraindications; risks are similar to multi-fraction SABR. • Single-fraction SABR plans require additional technical considerations to balance treatment time and interplay effects. • Prospective studies are needed for central targets, interstitial lung disease, and to maximise immunomodulatory effects. Stereotactic ablative radiotherapy (SABR) is a well-established treatment for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) and pulmonary oligometastases. The use of single-fraction SABR in this setting is supported by excellent local control and safety profiles which appear equivalent to multi-fraction SABR based on the available data. The resource efficiency and reduction in hospital outpatient visits associated with single-fraction SABR have been particularly advantageous during the COVID-19 pandemic. Despite the increased interest, single-fraction SABR in subgroups of patients remains controversial, including those with centrally located tumours, synchronous targets, proximity to dose-limiting organs at risk, and concomitant severe respiratory illness. This review provides an overview of the published randomised evidence evaluating single-fraction SABR in primary lung cancer and pulmonary oligometastases, the common clinical challenges faced, immunogenic effect of SABR, as well as technical and cost-utility considerations. [ABSTRACT FROM AUTHOR]

Abstract For tumor‐stage mycosis fungoides, systemic therapy in combination with skin‐directed local therapy is the mainstay of treatment. Here, we report a case where a tumor‐stage mycosis fungoides of the scalp showed a remarkable response to single fraction palliative radiotherapy.

• Prospective, multicenter, phase I/II trial of 19 Gy single fraction prostate SBRT. • Urinary and rectal toxicity was mild at the 18-month follow-up. • Impact on quality of life was minimal and biochemical response rate acceptable. • Longer follow-up is needed to assess long-term toxicity and disease control. To assess in a prospective, multicenter, single-arm phase I/II study the early safety and efficacy profile of single fraction urethra-sparing stereotactic body radiotherapy (SBRT) for men with localized prostate cancer. Patients with low- and intermediate-risk localized prostate cancer without significant tumor in the transitional zone were recruited. A single-fraction of 19 Gy was delivered to the prostate, with 17 Gy dose-reduction to the urethra. Intrafraction motion was monitored using intraprostatic electromagnetic transponders with intra-fraction correction of displacements exceeding 3 mm. Genitourinary (GU), gastrointestinal (GI), and sexual toxicity during the first 18 months were evaluated using the CTCAE v4.0 grading scale. Quality of life was assessed using the International Prostate Symptom Score, the Expanded Prostate Cancer Index composite 26 score, and the International Index of Erectile Function score. Among the 45 patients recruited in 5 centers between 2017 and 2022, 43 received the single fraction without protocol deviations, and 34 had a minimal follow-up of 18 months. The worst GU toxicity was observed at day-5 after SBRT (42.5 % and 20 % with grade 1 and 2, respectively), returning to baseline at week-12 and month-6 (<3% with grade 2), with a 12 % grade 2 flare at month 18. Gl toxicity was mild in the acute phase, with no grade ≥ 2 events (12 % grade 1 at month 6). Grade-3 proctitis was observed in one patient at month 12, with < 3 % grade 2 toxicity at month 18. Mean GU and GI bother scores showed a decline at day 5, a complete recovery at month 6, and a flare between month 12 and 18. Mean PSA dropped from 6.2 ng/ml to 1.2 ng/ml at month 18 and 0.7 ng/ml at month 24. After a median follow-up time of 26 months, 3 biochemical failures (7 %) were observed at month 17, 21 and 30. In this multicenter phase I/II trial, we demonstrated that a 19 Gy single-fraction urethra-sparing SBRT is feasible and associated with an acceptable toxicity rate, mostly returning to the baseline at week-12 and with a symptoms flare between months 12 and 18. Longer follow-up is needed to assess the potential long-term adverse effects and the disease control efficacy. [ABSTRACT FROM AUTHOR]

• Continuous fluoroscopy during MV delivery allows for markerless real time tumor tracking. • 3D lung tumor position monitoring was based on template matching and triangulation. • Lung tumor tracking was possible for >70% of the time during single fraction 34Gy lung SBRT. • Longitudinal, lateral and vertical position of the tumor was within 3 mm PTV margin 85.3% of the time. • The total time from first set-up imaging to end of the last arc was 18.3–31.4 min (mean = 23.4, SD = 4.1). Positional verification during single fraction lung SBRT could increase confidence and reduce the chance of geographic miss. As planar 2DkV imaging during VMAT irradiation is already available on current linear accelerators, markerless tracking based on these images could offer widely available and low-cost verification. We evaluated treatment delivery data and template matching and triangulation for 3D-positional verification during free-breathing, single fraction (34 Gy), 10 MV flattening-filter-free VMAT lung SBRT. Tumor tracking based on kV imaging at 7 frames/second was performed during irradiation in 6 consecutive patients (7 lesions). Tumor characteristics, tracking ability, comparison of tracking displacements with CBCT-based shifts, tumor position relative to the PTV margin, and treatment times are reported. For all 7 lesions combined, 3D tumor position could be determined for, on average, 71% (51–84%) of the total irradiation time. Visually estimated tracked and automated match +/− manually-corrected CBCT-derived displacements generally agreed within 1 mm. During the tracked period, the longitudinal, lateral and vertical position of the tumor was within a 5 mm/3 mm PTV margin 95.5/85.3% of the time. The PTV was derived from the ITV including all tumor motion. The total time from first set-up imaging to end of the last arc was 18.3–31.4 min (mean = 23.4, SD = 4.1). 3D positional verification during irradiation of small lung targets with limited motion, was feasible. However, tumor position could not be determined for on average 29% of the time. Improvements are needed. Margin reduction may be feasible. Imaging and delivery of a single 34 Gy fraction was fast. [ABSTRACT FROM AUTHOR]

Background and Purpose: Magnetic resonance imaging (MRI)-guided focal salvage high-dose-rate brachytherapy (FS-HDR-BT) is one of the treatment options for radiorecurrent localized prostate cancer. However, due to the invasive nature of the treatment, not all patients are eligible. Magnetic resonance linear accelerator (MR-Linac) systems open up new treatment possibilities and could potentially replace FS-HDR-BT treatment. We conducted a planning study to investigate the feasibility of delivering a single 19 Gy dose to the recurrent lesion using a 1.5 Tesla MR-Linac system. Materials and Methods: Thirty patients who underwent FS-HDR-BT were included. The clinical target volume (CTV) encompassed the visible lesion plus a 5 mm margin. Treatment plans were created for a 1.5 Tesla MR-Linac system using a 1 mm planning target volume (PTV) margin. A dose of 19 Gy was prescribed to ≥ 95% of the PTV. In case this target could not be reached, i.e. when organs-at-risk (OAR) constraints were violated, a dose of ≥ 17 Gy to ≥ 90% of the PTV was accepted. MR-Linac plans were compared to clinical FS-HDR-BT plans. Results: Target dose coverage was achieved in 14/30 (47%) FS-HDR-BT plans and 17/30 (57%) MR-Linac plans, with comparable median D95% and D90%. In FS-HDR-BT plans, a larger volume reached ≥ 150% of the prescribed dose. Urethra D10%, rectum D1cm3, and rectum D2cm3 were lower in the FS-HDR-BT plans, while bladder dose was comparable for both modalities. Conclusion: Single fraction treatment of recurrent prostate cancer lesions may be feasible using stereotactic body radiotherapy (SBRT) on a MR-Linac system.

Abstract Background To update the clinical outcome of an elderly women cohort with early breast cancer who underwent accelerated partial breast irradiation (APBI) based on a post-operative single fraction of multicatheter interstitial high dose–rate brachytherapy (MIB). Material and methods A single institution retrospective cohort study was performed focusing on elderly patients (≥ 65 years old) presenting a low-risk breast carcinoma treated by lumpectomy plus axillary evaluation followed by MIB APBI. A single fraction of 16 Gy was prescribed on the 100% isodose. Clinical outcome at 5 years was reported based on local relapse free survival (LRFS), specific survival (SS) and overall survival (OS). Late toxicity was evaluated. Cosmetic results were evaluated clinically by the physician. Results Between January 2012 and August 2015, 48 women (51 lesions) were treated. Median age was 77.7 years (range: 65–92) with a median tumor size of 12 mm (range: 3–32). Five patients (pts) presented an axillary lymph node involvement (4 Nmic, 1 N1). Invasive ductal carcinoma was the most frequent histology type (86.3%). With a median follow–up of 64 months (range: 56–71), no local relapse occurred while 1 pt. developed an axillary relapse (2.1%). No Grade 3 or higher late toxicity was observed while 16 late toxicities occurred (G1: 14 events [87.5%) mainly G1 breast fibrosis). The rate of excellent cosmetic outcome was 76.4%. Conclusion We confirmed the safety of the process and remained encouraging clinical outcome of a post-operative single fraction of MIB ABPI in the elderly. This approach leads to consider a very APBI as an attractive alternative to intra-operative radiation therapy while all the patients will be good candidates for APBI in regards to the post-operative pathological report.

Objectives: Stereotactic body radiotherapy (SBRT) is a consolidate treatment for inoperable early-stage lung tumors, usually delivered in single or multi-fraction regimens. We aimed to compare these two approaches in terms of local effectiveness, safety and survival. Materials and methods: Patients affected by medically inoperable early-stage lung tumor were treated at two Institutions with two different schedules: 70 Gy in ten fractions (TF) (BED10: 119 Gy) or 30 Gy in single fraction (SF) (BED10: 120 Gy). Results: 73 patients were treated with SBRT delivered with two biological equivalent schedules: SF (44) and TF (29). The median follow-up was 34 months (range 3–81 months). Three-year Overall survival (OS) was 57.9%, 3-year cancer-specific survival (CSS) was 77.2%, with no difference between treatment groups. Three-year progression-free survival (LPFS) was 88.9% and did not differs between SF and TF. Overall, four cases (5.4%) of acute grade ≥ 3 pneumonitis occurred. No differences in acute and late toxicity between the two groups were detected. Conclusion: SF and TF seems to be equally safe and effective in the treatment of primary inoperable lung tumors especially for smaller lesion. The SF may be preferentially offered to reduce patient access to hospital with no negative impact on tumor control and survival. [ABSTRACT FROM AUTHOR]

Purpose: Accelerated partial breast irradiation (APBI) represents a validated technique for low-risk breast cancer. Recently, ultra-APBI (uAPBI) using fewer than 5 fractions was described in the literature. We compared clinical outcomes and late toxicity after APBI or uAPBI in older patients.Methods and Materials: Two cohorts of older patients (aged ≥70 years) with low-risk breast cancer treated with APBI (interstitial brachytherapy) were analyzed retrospectively. A total dose of 34 Gy in10 fractions (APBI) or 16 Gy in 1 fraction (uAPBI) was delivered from 2004 to 2012 and from 2013 to 2018, respectively. Oncologic outcome analyzed the cumulative incidence of local relapse, regional relapse, and distant metastases with disease-free survival, cause-specific survival, and overall survival. Late toxicity and cosmetic results were investigated.Results: One hundred fifty-seven patients (APBI, n = 109 patients; uAPBI, n = 48 patients) underwent APBI according to the same selection criteria. Apart from the median follow-up (97 vs 72 months for APBI and uAPBI; P < .002), no significant difference was noted between the 2 groups. Regarding 6-year oncologic outcome, no significant difference was observed between APBI and uAPBI for local recurrence (1.3% vs 0%; P = .4), regional recurrence (2.5% vs 2.3%; P = .9), distant metastases (4.3% vs. 2.4%; P = .6), disease-free survival (85.2% vs. 82.2%; P = .8), cause-specific survival (96.7% vs. 96.2%; P = .9), and overall survival (86.7% vs. 82.2%; P = .7). Regarding late toxicity, no significant difference was observed between APBI and uAPBI (total complication number, 45 vs 33%; P = .173) with only grade 1 (88.4% vs. 95%) and grade 2 (11.6% vs. 5%) late toxicities (P = .677). Similarly, no significant difference was observed for excellent/good cosmetic results between the 2 cohorts (P = .98).Conclusions: We report the first study comparing APBI versus uAPBI in a cohort of older patients with low-risk breast cancer. No significant difference was found between the 2 treatment groups regarding oncologic outcome, late toxicity, and cosmetic result. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients with breast cancer. [ABSTRACT FROM AUTHOR]

Stereotactic ablative body radiation therapy (SABR) is a well-established alternative to surgery for early stage non–small-cell lung cancer (NSCLC). While SABR is typically delivered in 3 to 5 fractions, randomized trials have shown single-fraction SABR to be a reasonable alternative. We present the case of a 66-year-old male with history of cholangiocarcinoma who was subsequently diagnosed with peripheral early stage NSCLC and treated in mid-inspiration breath hold (BH) to 34 Gy in 1 fraction on a magnetic resonance (MR)-guided linear accelerator, with treatment delivery completed in 17 minutes. Visual biofeedback was utilized to maximize patient compliance with appropriate depth of inspiration BH and improve overall treatment delivery time efficiency. The benefits of single- vs multifraction SABR and unique advantages of MR guidance that are particularly well-suited for single-fraction SABR are reviewed. [ABSTRACT FROM AUTHOR]

• Of 180 patients who received 19 Gy high-dose-rate brachytherapy (HDR-BT) for localised prostate cancer, with a median follow up of 36 months, 19 (10.6%) patients developed biochemical recurrence of which 13 had a local relapse, including 7 at the site of dominant intraprostatic nodule (DIL). • The 19 biochemical recurrences (failures) were matched to 19 control patients, who were matched to pre-treatment CTV size, Gleason score, T stage, risk category and presence of a DIL. For these patients, clinical and dosimetric parameters were analysed to see if there were any predictors for biochemical recurrence, local recurrence or recurrence within the DIL. • There were no statistically significant differences in all OARs, CTV, PTV and DIL dosimetric parameters between the failures and controls. • In univariate analysis, there were no statistically significant clinical or dosimetric parameters that predicted for biochemical progression free survival, local recurrence free survival or DIL recurrence free survival. • Whilst a large proportion of patients recur at the site of original disease, and these results may support rationale for further dose escalation, in our cohort actual dose delivered to DIL was around 26 Gy. Other studies employing dose escalation to whole gland or focal boost have failed to show improved clinical outcomes to justify this approach, hence HDR-BT should be undertaken using a minimum of two fractions. Long-term follow up of single dose high-dose rate brachytherapy (HDR BT) for localised prostate cancer has revealed higher than expected rates of biochemical and local failure. This study aimed (i) to investigate the pattern of relapse within the prostate with reference to the initial site of disease in those patients; and (ii) to examine if there were any relationships between the HDR BT dosimetric parameters to these areas of recurrence. A retrospective review of treatment records of patients who received 19 Gy single fraction of HDR BT was carried out. A matched pair analysis used one control for each biochemical recurrence case matched with pre-treatment Clinical target volume (CTV) size, Gleason score, T stage, risk category and presence of an identifiable dominant intraprostatic nodule (DIL) for each biochemical recurrence case identified. For all datasets, the pre HDR BT DILs were delineated on the diagnostic pre-treatment T2-weighted MRI and planning CT images. For patients with local recurrence post HDR BT, the recurrent nodules were contoured on the diagnostic T2-weighted MRI and choline PET which were registered to the original HDR BT planning CT. Dosimetric parameters of CTV, planning target volume (PTV), DIL and organs at risk (OARs) were evaluated. Wilcoxon signed-rank test was performed to investigate if there were any significant differences in dosimetric parameters between cases and controls. Cox regression analysis was performed to explore if there were any clinical and dosimetric parameters predicting for biochemical progression free survival (bPFS), local recurrence free survival (LR-PFS) and DIL recurrence free survival (DIL-PFS). Between 2013 and 2018, 180 patients received 19 Gy HDR-BT monotherapy. With a median follow up of 36 months, 19 (10.6%) patients developed biochemical recurrence. Of the 19 patients with biochemical failure, 13 had a local recurrence, including 7 who occurred at the site of DIL. Thirty-eight intermediate/high risk patients were included in the matched pair analysis. No statistically significant differences were found in all CTV, PTV, DIL and OAR dosimetric parameters between cases and controls (p > 0.05). For the Cox regression analysis, none of the covariates investigated were found to be statistically significant factors to predict for bPFS, LC-PFS and DIL-PFS. No associations between biochemical recurrences and HDR BT dosimetry were identified in our cohort of patients receiving 19 Gy single fraction HDR BT. A large proportion of recurrences occurred at the site of original disease. HDR BT for intermediate/high risk prostate cancer should be undertaken using a minimum of two fractions. [ABSTRACT FROM AUTHOR]

Background This study aimed to assess the efficacy of different radiation therapy regimens in treating patients with symptomatic bone metastases. Methodology A retrospective study was conducted by assigning patients with symptomatic bone metastases from different primary cancers into three groups, namely, Arms A, B, and C. The radiation dose delivered in each arm was as follows: 8 Gray (Gy) in a single fraction for Arm A, 20 Gy in five fractions at the rate of 4 Gy per fraction for Arm B, and 30 Gy in 10 fractions at the rate of 3 Gy per fraction for Arm C. Each arm consisted of 15 patients. A comparison was conducted across all three arms to evaluate pain relief based on the Visual Analog Scale (VAS), performance score improvement based on the Eastern Cooperative Oncology Group (ECOG), and analgesic requirement based on the World Health Organization (WHO) step ladder at one week, one month, and three months. Results The pain relief was measured using the VAS in three different arms, i.e., Arm A, B, and C. After one week, the pain relief was 66.67%, 60%, and 60%, respectively. After one month, it was 73.33% in all three arms. At three months, it was 80%, 86.67%, and 86.67%, respectively. The study also measured the improvement in the ECOG performance score. The improvement in all three arms was 60% after one week and 66.67% in Arm A and 73.33% in Arms B and C after one month. After three months, the improvement was 73.33%, 80%, and 80% in Arms A, B, and C, respectively. The decrease in analgesic usage was also measured in all three arms. After one week, it was 60% in all three arms. After one month, it was 66.67%, 73.33%, and 73.33% in Arms A, B, and C, respectively. At three months, it was 73.33%, 80%, and 80% in Arms A, B, and C, respectively. No significant statistical difference was found between the three arms. Conclusions The efficacy of a single 8 Gy arm was almost equivalent to that of other arms of multifractionated regimens in terms of improvement in pain and performance score and decreased use of analgesics for a short duration of follow-up. For high-volume cancer centers and patients with economic constraints, a single-fraction regime provides effective palliation for painful bone metastases., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Ahmed et al.)

Numerous nonmalignant diseases can be treated with radiation therapy (RT). Among them, Heterotopic Ossification (HO) is a benign condition resulting from several causes that can be successfully managed with ionizing radiation. More often seen in the hip area after major surgical procedures, HO is of major concern as it can lead to functional disorders, pain and even to joint ankylosis. We retrospectively analyzed the outcome of therapeutic irradiation for the prevention of HO in 14 patients treated in our hospital between 2005 and 2011. All patients were irradiated with a dose ranging from 7 to10 Gy in a single fraction for prevention of HO after surgery. After a median follow up of 126 months (range 96 – 156 months) none of our patients developed HO. Impaired wound healing or other post surgery complications like trochanteric nonunion were not observed. A single fraction of RT seems to be a sufficient, cost effective and safe treatment regimen. In our study we report excellent results as none of our patients developed HO.

Abstract Background Stereotactic body radiotherapy (SBRT) is an emerging treatment alternative for patients with localized prostate cancer. Promising results in terms of disease control and toxicity have been reported with 4 to 5 SBRT fractions. However, question of how far can the number of fractions with SBRT be reduced is a challenging research matter. As already explored by some authors in the context of brachytherapy, monotherapy appears to be feasible with an acceptable toxicity profile and a promising outcome. The aim of this multicenter phase I/II prospective trialis to demonstrate early evidence of safety and efficacy of a single-fraction SBRT approach for the treatment of localized disease. Methods Patients with low- and intermediate-risk localized prostate cancer without significant tumor in the transitional zone will be treated with a single SBRT fraction of 19 Gy to the whole prostate gland with urethra-sparing (17 Gy). Intrafractional motion will be monitored with intraprostatic electromagnetic transponders. The primary endpoint of the phase I part of the study will be safety as assessed by CTCAE 4.03 grading scale, while biochemical relapse-free survival will be the endpoint for the phase II. The secondary endpoints include acute and late toxicity, quality of life, progression-free survival, and prostate-cancer specific survival. Discussion This is the first multicenter phase I/II trial assessing the efficacy and safety of a single-dose SBRT treatment for patients with localized prostate cancer. If positive, results of ONE SHOT may help to design subsequent phase III trials exploring the role of SBRT monotherapy in the exclusive radiotherapy treatment of localized disease. Trial registration Clinicaltrials.gov identifier: NCT03294889; Registered 27 September 2017.

Introduction: The Gamma Knife® planning software (TMR 10, Elekta Instruments, AB, Sweden) affords two ways of defining the skull volume, the "historical" one using manual measurements (still perform in some centers) and the new one using image-based skull contours. Our objective was to assess the potential variation of the dose delivery calculation using consecutively in the same patients the two above-mentioned techniques. Materials and methods: We included in this self-case-control study, 50 patients, treated with GKRS between July 2016 and January 2017 in Lausanne University Hospital, Switzerland, distributed among four groups: convexity targets (n = 18), deep-seated targets (n = 13), vestibular schwannomas (n = 11), and trigeminal neuralgias (n = 8). Each planning was performed consecutively with the 2 skull definition techniques. For each treatment, we recorded the beam-on time (min), target volume coverage (%), prescription isodose volume (cm3), and maximal dose (Gy) to the nearest organ at risk if relevant, according to each of the 2 skull definition techniques. The image-based contours were performed using CT scan segmentation, based upon a standardized windowing for all patients. Results: The median difference in beam-on time between manual measures and image-based contouring was + 0.45 min (IQR; 0.2–0.6) and was statistically significant (p < 0.0001), corresponding to an increase of 1.28% beam-on time per treatment, when using image-based contouring. The target location was not associated with beam-on time variation (p = 0.15). Regarding target volume coverage (p = 0.13), prescription isodose volume (p = 0.2), and maximal dose to organs at risk (p = 0.85), no statistical difference was reported between the two skull contour definition techniques. Conclusion: The beam-on time significantly increased using image-based contouring, resulting in an increase of the total dose delivery per treatment with the new TMR 10 algorithm. Other dosimetric parameters did not differ significantly. This raises the question of other potential impacts. One is potential dose modulation that should be performed as an adjustment to new techniques developments. The second is how this changes the biologically equivalent dose per case, as related to an increased beam on time, delivered dose, etc., and how this potentially changes the radiobiological effects of GKRS in an individual patient. [ABSTRACT FROM AUTHOR]

Purpose: We sought to evaluate the feasibility and tolerability of a novel accelerated partial breast irradiation regimen delivered in a single fraction postoperatively.Methods and Materials: We enrolled 50 patients with low-risk, hormone-sensitive breast cancer from 2015 to 2018 on a prospective phase 1/2 trial to receive single-fraction, high-gradient partial-breast irradiation (SFHGPBI) 2 to 8 weeks after lumpectomy for node-negative, invasive, or in situ breast cancer. The high gradient was achieved by prescribing 20 Gy to the surgical bed and 5 Gy to the breast tissue within 1 cm of the surgical bed simultaneously in 1 fraction using external beam.Results: The median age was 65 (range, 52-84). Ten patients (20%) had small-volume ductal carcinoma in situ while the remainder had stage I disease. At a median follow-up of 25 months, we evaluated toxicity, patient- and physician-reported cosmesis, patient-reported quality of life (QOL), and initial tumor control. There was no Common Terminology Criteria for Adverse Events v4.0 grade 3+ toxicity. Only 34% of patients experienced grade 1 erythema. Good-to-excellent pretreatment cosmesis was present in 100% and 98% per physicians and patients, respectively, and did not change post-SFHGPBI. Quantitative cosmesis by percentage of breast retraction assessment significantly improved over time during the post-SFHGPBI period per mixed repeated measures modeling (P = .0026). QOL per European Organization for Research and Treatment of Cancer QOL Questionnaires C30 and BR-23 did not decline other than temporarily in the systemic therapy effects and hair loss domains, both of which returned to pretreatment values. There was 1 noninvasive in-breast recurrence in a separate untreated quadrant 18 months post-SFHGPBI and 1 isolated axillary recurrence 30 months post-SFHGPBI, both salvaged successfully. There were no distant recurrences or cancer-related deaths observed.Conclusions: Accelerated partial-breast irradiation delivered in a single fraction postoperatively using external beam techniques is a novel, feasible, well-tolerated regimen. SFHGPBI does not adversely affect cosmesis or QOL as reported by both physicians and patients. Initial tumor control rates are excellent, with longer follow-up required to confirm efficacy. [ABSTRACT FROM AUTHOR]

Numerous nonmalignant diseases can be treated with radiation therapy (RT). Among them, Heterotopic Ossification (HO) is a benign condition resulting from several causes that can be successfully managed with ionizing radiation. More often seen in the hip area after major surgical procedures, HO is of major concern as it can lead to functional disorders, pain and even to joint ankylosis. We retrospectively analyzed the outcome of therapeutic irradiation for the prevention of HO in 14 patients treated in our hospital between 2005 and 2011. All patients were irradiated with a dose ranging from 7 to 10 Gy in a single fraction for prevention of HO after surgery. After a median follow up of 126 months (range 96 – 156 months) none of our patients developed HO. Impaired wound healing or other post surgery complications like trochanteric nonunion were not observed. A single fraction of RT seems to be a sufficient, cost effective and safe treatment regimen. In our study we report excellent results as none of our patients developed HO. [ABSTRACT FROM AUTHOR]

To evaluate the clinical outcomes of a very-accelerated partial breast irradiation (vAPBI) in the elderly based on a single fraction of multicatheter interstitial high-dose rate brachytherapy (MIB). Mature results with a median follow-up of 5 years. From November 2012 to September 2014, 26 patients (pts) (≥70) with early breast cancer were enrolled in a prospective phase II trial (NCT01727011). After lumpectomy, intraoperative catheter implant was performed for postoperative APBI (single fraction 16 Gy). Surveillance was performed twice a year after APBI. Oncologic outcome (local [LRFS], metastasis-free survival, cancer-specific survival, and overall survival [OS]) as well as late toxicity and cosmetic outcome were investigated. Median age was 77 years [69–89]. After a median follow-up of 63 months [60–68], 5-year LRFS, metastasis-free survival, cancer-specific survival, and overall survival rates were 100%, 95.5%, 100%, and 88.5%, respectively. Late toxicity was observed in 5 pts (19.2%) with a total of five events: 3 pts G1 (60%); and 2 pts G2 (40%). The observed late side effects were breast pain in 1 pt (G2 cytosteatonecrosis with occasional acetaminophen consumption), hypopigmentation (puncture site) in 2 pts (G1) and breast fibrosis in 2 pts (G1: 1 pt; G2: 1 pt). Cosmetic evaluation was excellent for 21 pts (81%) and good for 2 pts (19%). For elderly with early breast cancer, a vAPBI using a single fraction of postoperative MIB (16 Gy) provides excellent oncologic results, mainly in terms of local control and cancer death. Late toxicity and cosmetic profile are acceptable. [ABSTRACT FROM AUTHOR]

Background: To update the clinical outcome of an elderly women cohort with early breast cancer who underwent accelerated partial breast irradiation (APBI) based on a post-operative single fraction of multicatheter interstitial high dose-rate brachytherapy (MIB).Material and Methods: A single institution retrospective cohort study was performed focusing on elderly patients (≥ 65 years old) presenting a low-risk breast carcinoma treated by lumpectomy plus axillary evaluation followed by MIB APBI. A single fraction of 16 Gy was prescribed on the 100% isodose. Clinical outcome at 5 years was reported based on local relapse free survival (LRFS), specific survival (SS) and overall survival (OS). Late toxicity was evaluated. Cosmetic results were evaluated clinically by the physician.Results: Between January 2012 and August 2015, 48 women (51 lesions) were treated. Median age was 77.7 years (range: 65-92) with a median tumor size of 12 mm (range: 3-32). Five patients (pts) presented an axillary lymph node involvement (4 Nmic, 1 N1). Invasive ductal carcinoma was the most frequent histology type (86.3%). With a median follow-up of 64 months (range: 56-71), no local relapse occurred while 1 pt. developed an axillary relapse (2.1%). No Grade 3 or higher late toxicity was observed while 16 late toxicities occurred (G1: 14 events [87.5%) mainly G1 breast fibrosis). The rate of excellent cosmetic outcome was 76.4%.Conclusion: We confirmed the safety of the process and remained encouraging clinical outcome of a post-operative single fraction of MIB ABPI in the elderly. This approach leads to consider a very APBI as an attractive alternative to intra-operative radiation therapy while all the patients will be good candidates for APBI in regards to the post-operative pathological report. [ABSTRACT FROM AUTHOR]

Purpose: High-dose-rate brachytherapy (HDR-BT) delivered in a single fraction as monotherapy is a potential treatment modality for low- and intermediate-risk prostate cancer (LIR-PC); however, outcome data with this technique remain limited. Here we describe our institutional HDR monotherapy experience and report the efficacy and toxicity of this treatment. Material and methods: LIR-PC patients who received a definitive single fraction HDR-BT during 2013-2017 were retrospectively identified. The intended HDR monotherapy dose was 19 Gy in one fraction. Acute (< 90 days) and late (≥ 90 days) toxicity was assessed using CTCAE version 4.03. Trends in prostate-specific antigen (PSA) and American Urological Association (AUA) symptom scores after treatment were assessed using Bayesian linear mixed models. The Kaplan-Meier method was used to evaluate biochemical failure-free survival (BFFS). Results: 28 patients with median follow-up of 23.6 months were identified. The median age at treatment was 65 years (48-83). The NCCN risk groups were low in 14, favorable intermediate in 10, and unfavorable intermediate in 4 patients. There were 5 (18%) and 0 (0%) acute grade 2 genitourinary (GU) and gastrointestinal (GI) toxicities, respectively, and one (4%) acute grade 3 GU toxicity. There were no late grade 3 toxicities, and 5 (18%) and 0 (0%) late grade 2 GU and GI toxicities respectively. PSA values and AUA symptom scores decreased significantly after treatment. There were 3 biochemical failures with the two- and three-year BFFS of 90.7% and 80.6%, respectively. Conclusions: Early results from a single institution suggest that single fraction HDR-BT with 19 Gy has limited toxicity, although with suboptimal biochemical control. [ABSTRACT FROM AUTHOR]

Abstract Purpose To evaluate acute and late genitourinary toxicity, the gastrointestinal toxicity, and the long-term biochemical control after high-dose-rate (HDR) monotherapy in one fraction (20.5 Gy). Materials and Methods Between May 2011 and October 2014, 60 consecutive patients with low- and intermediate-risk prostate cancer were treated; the median followup was 51 months (range 30–79). All patients received one implant and one fraction of 20.5 Gy HDR real-time U/S planned with transperineal hyaluronic acid injection into the perirectal. Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, Version 4.0 (CTAE v4.03) by the National Cancer Institute. Biochemical failure was defined according to the "Phoenix definition". Results Our experience in a single fraction of 20.5 Gy HDR brachytherapy is well-tolerated. No intraoperative or perioperative complications occurred. Grade 1 acute genitourinary toxicity occurred in 36% of patients, Grade 2 or more was not observed, only 1 patient requiring the use of a catheter for 7 days in the immediate postoperative period. No gastrointestinal toxicity was observed. No chronic toxicity has been observed after treatment. Morbidity is practically the same as that obtained with 19 Gy in our previously published article but the actuarial biochemical control was better, 82% (±3%) at 6 years. Conclusions A single dose of 20.5 Gy resulted in a low genitourinary morbidity and no gastrointestinal toxicity and achieves good levels of biochemical disease control. [ABSTRACT FROM AUTHOR]

• Delivery of single-fraction SABR to lung tumors on a 0.35 T MR-linac resulted in a 3-year local control rate of 97%. • Only 1 patient (2%) developed grade ≥3 toxicity, which was chest wall pain. • MR-guided SABR delivered using repeated breath-holds and with automatic beam gating, achieves good tumor control and low toxicity. Magnetic resonance imaging (MR)-guided radiotherapy permits continuous intrafraction visualization and use of automatic triggered beam delivery, with use of smaller planning target volumes (PTV). We report on long-term clinical outcomes following MR-guided single fraction (SF) lung SABR on a 0.35 T linac. Details of patients treated with SF-SABR for lung tumors were accessed from an ethics approved institutional database. A breath-hold 3D MR simulation scan was performed using a true FISP sequence, followed by a breath-hold 3D CT scan. The gross tumor volume (GTV) was first contoured on the breath-hold CT scan, which was then compared with contours on the 3D MR scan, before the GTV was finalized. SABR plans used step-and-shoot IMRT beams to a PTV derived by adding a 5 mm margin to the breath-hold GTV, and a 3 mm gating window was used. SABR was delivered during repeated breath-holds, using automatic beam gating with continuous visualization of the GTV in a sagittal MR plane. Between 2018–2022, 50 consecutive patients were treated, and 69% had a primary non-small cell lung cancer. Median PTV was 11.2 cc (range 3.9–53.5); 80% of GTV's were located ≤2.5 cm from the chest wall. Prescribed doses were 34 Gy (in 58%), 30 Gy (32%), or between 20–28 Gy (10%). After a median follow-up of 18.1 months (95% CI 12.8–23.5), the 2-year survival was 82% (89% for primary NSCLC and 62% for metastases). After a median follow-up of 16.1 months (95% CI 11.2–21.1), local recurrences developed in 2 patients (4%). The 3-year local control rate was 97%, and just 1 patient developed grade ≥3 toxicity (chest wall pain). MR-guided SF-SABR delivery to lung tumors on a 0.35 T linac, using repeated breath-holds with automatic beam gating, achieves good tumor control and low toxicity. [ABSTRACT FROM AUTHOR]

Purpose : To validate the feasibility of a single-fraction high-dose-rate brachytherapy (HDRBT) boost for prostate cancer using real-time transrectal ultrasound (TRUS) based planning. Material and methods : From August 2012 to September 2015, 126 patients underwent a single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning. External beam radiation therapy (EBRT) (37.5 Gy/15 fractions, 44 Gy/22 fractions, or 45 Gy/25 fractions) was performed before (31%) or after (69%) HDRBT boost. Genito-urinary (GU) and gastro-intestinal (GI) toxicity were assessed 4 and 12 months after the end of combined treatment using the international prostate symptom score scale (IPSS) and the common terminology criteria for adverse events (CTCAE) v3.0. Results : All dose-planning objectives were achieved in 90% of patients. Prostate D 90 ≥ 105% and ≤ 115% was achieved in 99% of patients, prostate V 150 ≤ 40% in 99%, prostate V 200 < 11% in 96%, urethra D 10 < 120% for 99%, urethra V 125 = 0% in 100%, and rectal V 75 < 1 cc in 93% of patients. Median IPSS score was 4 at baseline and did not change at 4 and 12 months after combined treatment. No patients developed ≥ grade 2 GI toxicity. With a median follow-up of 10 months, only two patients experienced biochemical failure. Among patients who didn’t receive ADT, cumulative percentage of patients with PSA ≤ 1 ng/ml at 4 and 18 months was respectively 23% and 66%. Conclusions : Single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning achieves consistently high dosimetry quality. In combination with EBRT, toxicity outcomes appear promising. A longer follow-up is needed to assess long-term outcome and toxicities.