Search

Purpose: Stereotactic body radiotherapy is pivotal in the treatment of lung tumors, demonstrating effective local control. However, challenges persist with intra-fractional anatomical changes and organs at risk during delivery. Magnetic resonance-guided online adaptive stereotactic body radiotherapy (MRgSBRT) represents a novel technique promising to achieve safe delivery of ablative doses with improved outcomes for primary lung tumors or lung oligometastases., Methods: In this single-institution retrospective analysis, we evaluated 64 patients (92 lesions) with primary lung cancer or lung oligometastases treated with MRgSBRT. Using Kaplan-Meier method and log-rank test; we estimated local control (LC), local progression-free survival (LPFS), distant progression-free survival (DPFS), and overall survival (OS)., Results: A total of 64 patients (92 lesions) treated with MRgSBRT were included comprising 14.1% primary lung cancer lesions and 85.9% lung oligometastases. Median total dose, fraction number, fraction dose and BED 10 were 50 Gy (range, 21-70 Gy), 5 (range, 1-10), 10 Gy (range, 6-34 Gy), 100 Gy (range, 48-180.0 Gy) respectively. Of the 420 fractions administered, 88.6% (n = 372) involved on-table adapted plans. Median LPFS was not reached and the 1‑ and 3‑year LPFS rates were 96.3% (95% CI 92.4-100.0%) and 86.4% (95% CI 76.9-95.9%), respectively. No local recurrences were observed post-treatment with a total dose of > 50 Gy, BED10 > 100 Gy, fractional dose of > 10 Gy or a CCI > 0.96., Conclusion: Our study of MRgSBRT in 92 lung lesions revealed a 1-year and 3‑year LPFS rates of 96.3 and 86.4%, respectively without ≥ grade 3 toxicity. Future prospective studies evaluating lung MRgSBRT are awaited., Competing Interests: Conflict of interest: G. Ugurluer, N. Dincer, T.Z. Mustafayev, G. Gungor, M.U. Abacioglu, M. Sengoz, E. Ozyar and B. Atalar declare that they have no competing interests., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To investigate the treatment outcomes of extracranial oligometastatic colorectal cancer (CRC) patients treated with stereotactic body radiotherapy (SBRT)., Materials and Methods: The clinical data of 388 extra-cranial oligometastatic CRC (≤ 5 lesions) patients and 463 lesions treated with SBRT at 19 cancer institutions were retrospectively analyzed. The prognostic factors predicting overall survival (OS), progression-free survival (PFS), and local control (LC) were assessed in uni- and multivariable analyses., Results: The median age was 62 years (range, 29-92 years). The majority of the patients (90.5%) received surgery and systemic treatment for their primary tumor, had ≤ 2 metastasis (83.3%), had single organ involvement (90.3%), and staged using flouro-deoxyglucose positron emission tomography (FDG-PET/CT) (76%). The median fraction and total radiation doses were 10 Gy (range: 6-34 Gy) and 50 Gy (range: 8-64 Gy), respectively, delivered in a median of 4 fractions (range: 1-8). The median follow-up time for the entire cohort was 30.7 months (interquartile range: 27.0-34.3 months). The 3‑year OS, PFS, and LC rates were 64.0%, 42.3%, and 72.7%, respectively. The 3‑year LC rate was significantly higher in patients receiving BED 10  ≥ 100 Gy than those receiving BED 10  < 100 Gy (76.0% vs. 67.3%; p = 0.04). The 3‑year PFS and OS rates were higher in patients receiving BED 10  ≥ 100 Gy than those receiving BED 10  < 100 Gy (33.2% vs. 25.2%; p = 0.03; 53.7% vs.  44.8%; p = 0.02). Single metastasis and complete response after SBRT were independent prognostic factors for survival in multivariable analysis., Conclusions: In this multi-center study, we demonstrated that SBRT is an effective treatment option of metastatic lesions in oligometastatic CRC patients by providing promising LC rates. Higher SBRT doses beyond BED 10  ≥ 100 Gy were associated with improved LC and survival. LC of treated lesion and lower tumor burden after SBRT were associated with better outcomes., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The objective of our study is to evaluate breast cancer patients with BRCA1 or BRCA2 gene mutations and compare them with patients without these mutations. Specifically, we aim to assess the acute side effects of radiotherapy in both groups., Methods: Data were collected from four participating centers, comprising information from 73 patients who underwent known mutation analysis and had complete data. Patients were monitored on a weekly basis throughout their treatment for acute toxicity, which was evaluated using the Radiation Therapy Oncology Group (RTOG) acute toxicity criteria., Results: The median age of the 73 patients included in our study was 43. Among them, 17 had BRCA1-positive mutations and 19 had BRCA2-positive mutations. Invasive ductal carcinoma was present in 67 patients, all of whom underwent surgery. Of the patients, 57 received conventional radiotherapy doses, while 16 received hypofractionated radiotherapy doses. During follow-up, metastasis occurred in three patients. In BRCA-positive patients, those under 40 years of age (p<0.001), with high nodal positivity (p=0.008), grade 2-3 (p=0.022), and lymphovascular invasion (p=0.002) were significantly more frequent compared to BRCA-negative patients (p<0.001). The median survival was 35.8 months. Grade 1 dysphagia developed in seven BRCA-negative patients and four BRCA-positive patients, with no significant difference observed between the two groups (p=0.351). There was also no statistical difference observed in the occurrence of grade 2-3 skin reactions, with 11 BRCA-negative patients and eight BRCA-positive patients experiencing these side effects., Conclusion: Our study supports existing literature by identifying an association between the presence of BRCA mutations and young age, nodal status, grade, and lymphovascular invasion. Additionally, we found no significant difference in the occurrence of radiotherapy toxicity between BRCA-positive and BRCA-negative patients. These findings suggest that radiotherapy can be safely administered to BRCA-positive patients after breast-conserving surgery or mastectomy. Keywords for our study include breast cancer, BRCA mutation, radiotherapy, and side effects., Competing Interests: No conflict of interest was declared by the authors.

Purpose: The purpose of this multicenter retrospective study was to analyze the clinical and radiological effects of bevacizumab (BV) on radionecrosis (RN) that developed after stereotactic radiotherapy (SRT) for brain metastasis., Methods: Forty patients with SRT related symptomatic brain RN treated in 10 radiation oncology centers were analyzed. The clinical response to BV treatment was categorized as follows: complete (no additional treatment required), partial (requiring either steroids or repeat BV), and unresponsive (requiring surgery). The radiological features of brain RN were analyzed in 10 patients whose serial MRI scans were available after corticosteroid and BV treatments., Results: BV was used as a first line treatment in 11 (27.5%) and as a second line treatment in 29 (72.5%) of patients. The neurological symptoms regressed in 77.5% of patients after treatment with BV (45% complete response, 32.5% partial response). The median edema volume increased from 75.9 cc (range: 5.9-125.8 cc) at RN to 113.65 cc (range: 1.5-382.1 cc) after use of corticosteroids, representing a rate of 39.8% increase (p = 0.074). However, after BV treatment the median volume of edema decreased to 19.5 cc (range: 0-163.3 cc) which represents a difference of 62.2% (p = 0.041) from RN., Conclusion: The use of BV caused clinical response rate of 77.5% and a good radiological response in corticosteroid unresponsive patients. The role of BV should be further investigated in prospective studies., (© 2024. The Author(s).)

Purpose: Prostate cancer has emerged as a significant public health challenge in the Middle East, characterized by rising incidence rates and a concerning mortality-to-incidence ratio. Yet, despite these alarming trends, data regarding prostate cancer awareness in the region remain limited. To address this critical knowledge gap, this study investigates prostate cancer awareness within the Middle East., Materials and Methods: A cross-sectional survey was performed among 5,913 men age 40 years and older across 14 Middle Eastern countries between January 1, 2022, and July 31, 2023. Excluding those with a history of prostate cancer, a validated questionnaire assessed prostate cancer awareness. Data were analyzed using frequencies and percentages for categorical variables, medians and ranges for continuous variables, and Pearson chi-square analysis for relationships between education levels and awareness of prostate cancer., Results: The survey achieved a 74.9% response rate, with 4,431 male participants. Regarding prostate cancer awareness, 83.8% of participants had heard of the disease. However, only 31.0% correctly identified it as the most common malignancy in men, and 21.8% believed it affects both sex. Awareness of screening was limited, with just 19.1% recognizing the prostate-specific antigen test's role. Additionally, participants had a pessimistic view, with a mean perception that 75% of patients with prostate cancer die from the disease, rather than from other causes. Higher education levels were associated with significantly increased awareness of prostate cancer ( P < .001)., Conclusion: This study reveals that while general awareness of the disease exists, crucial knowledge deficits regarding risk factors, screening, and prognosis are evident. Addressing these knowledge gaps through culturally tailored education may improve early detection rates, treatment outcomes, and ultimately reduce the burden of prostate cancer in the Middle East.

Stereotactic body radiotherapy is a highly effective form of radiation therapy for palliation of bone metastases, but it can also lead to rare but severe side effects, such as myonecrosis. According to the literature, the incidence of myonecrosis after stereotactic body radiotherapy is low and mostly dose dependent. It is crucial to consider the potential impact of immunotherapy and other systemic therapies in the assessment. The course of radiation myonecrosis can vary, and corticosteroids or vascular endothelial growth factor inhibitors may potentially play a role in its treatment. Herein, we report two patients presenting with myonecrosis after stereotactic body radiotherapy for bone metastasis., (Copyright © 2024. Published by Elsevier Masson SAS.)

Purpose: Stereotactic body radiotherapy (SBRT) is an effective treatment for adrenal gland metastases, but it is technically challenging and there are concerns about toxicity. We performed a multi-institutional pooled retrospective analysis to study clinical outcomes and toxicities after MR-guided SBRT (MRgSBRT) using for adrenal gland metastases., Methods and Materials: Clinical and dosimetric data of patients treated with MRgSBRT on a 0.35 T MR-Linac at 11 institutions between 2016 and 2022 were analyzed. Local control (LC), local progression-free survival (LPFS), distant progression-free survival (DPFS) and overall survival (OS) were estimated using Kaplan-Meier method and log-rank test., Results: A total of 255 patients (269 adrenal metastases) were included. Metastatic pattern was solitary in 25.9 % and oligometastatic in 58.0 % of patients. Median total dose was 45 Gy (range, 16-60 Gy) in a median of 5 fractions, and the median BED10 was 100 Gy (range, 37.5-132.0 Gy). Adaptation was done in 87.4 % of delivered fractions based on the individual clinicians' judgement. The 1- and 2- year LPFS rates were 94.0 % (95 % CI: 90.7-97.3 %) and 88.3 % (95 % CI: 82.4-94.2 %), respectively and only 2 patients (0.8 %) experienced grade 3 + toxicity. No local recurrences were observed after treatment to a total dose of BED10 > 100 Gy, with single fraction or fractional dose of > 10 Gy., Conclusions: This is a large retrospective multi-institutional study to evaluate the treatment outcomes and toxicities with MRgSBRT in over 250 patients, demonstrating the need for frequent adaptation in 87.4 % of delivered fractions to achieve a 1- year LPFS rate of 94 % and less than 1 % rate of grade 3 + toxicity. Outcomes analysis in 269 adrenal lesions revealed improved outcomes with delivery of a BED 10  > 100 Gy, use of single fraction SBRT and with fraction doses > 10 Gy, providing benchmarks for future clinical trials., (© 2024 The Authors.)

Aims: To present the preliminary results on the clinical utilisation of an online daily adaptive magnetic resonance-guided radiation therapy (MRgRT) for various gynaecological cancers., Materials and Methods: Twelve patients treated between September 2018 and June 2022 were included. Six patients (50%) were treated with pelvic radiation therapy followed by MRgRT boost as brachytherapy boost was ineligible or unavailable, three patients (25%) were treated with pelvic MRgRT followed by high dose rate brachytherapy, two patients (16.7%) were treated with only MRgRT, one patient (8.3%) was treated with linear accelerator-based radiation therapy followed by MRgRT boost for bulky iliac lymph nodes., Results: The median age was 56.5 years (range 31-86 years). Eight patients (66.7%) had a complete response, three patients (25%) had a partial response and one patient (8.3%) died due to acute renal failure. The mean follow-up time was 11.2 months (range 3.1-42.6 months). The estimated 1-year overall survival was 88.9%. The median treatment time was 47 days (range 10-87 days). During external beam radiation therapy, 10 (83.3%) patients had concomitant chemoradiotherapy. Pelvic external beam radiation therapy doses for all cohorts were 45-50.4 Gy with a fraction dose of 1.8 Gy. The median magnetic resonance-guided boost dose was 32 Gy (range 20-50 Gy) and fraction doses ranged between 4 and 10 Gy. Three patients were treated with intracavitary high dose rate brachytherapy (26-28 Gy in four to five fractions). None of the patients had grade >3 late genitourinary toxicities., Conclusion: MRgRT is reliable and clinically feasible for treating patients with gynaecological cancers alone or in combination with brachytherapy with an acceptable toxicity and outcome. MRgRT boost could be an option when brachytherapy is not available or ineligible., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: The standard of care in locally advanced cervical cancer (LACC) is concomitant chemoradiotherapy followed by high-dose-rate brachytherapy (HDR-BT). Although previous studies compared HDR-BT with stereotactic body radiotherapy (SBRT), there is scarce data regarding the dosimetric outcomes of stereotactic MR-guided adaptive radiation therapy (SMART) boost in lieu of HDR-BT., Methods and Materials: In this single-institutional in-silico comparative study, LACC patients who were definitively treated with external beam radiotherapy followed by HDR-BT were selected. Target volumes and organs at risk (OARs) were delineated in MRI and HDR-planning CT. An HDR-BT and a SMART boost plan were generated with a prescribed dose of 28 Gy in four fractions for all patients. The HDR-BT and SMART boost plans were compared in regard to target coverage as well OARs doses., Results: Mean EQD2 D90 to HR-CTV and IR-CTV for HDR-BT plans were 89.7 and 70.5 Gy, respectively. For SMART, the mean EQD2 D90 to HR-PTV, HR-CTV, and IR-CTV were 82.9, 95.4, and 70.2 Gy, respectively. The mean D 2cc EQD2 of bladder, rectum, and sigmoid colon for HDR-BT plans were 86.4, 70.7, and 65.7 Gy, respectively. The mean D 2cc EQD2 of bladder, rectum, and sigmoid colon for SMART plans were 81.4, 70.8, and 73.6 Gy, respectively. All dose constraints in terms of target coverage and OARs constraints were met for both HDR-BT and SMART plans., Conclusions: This dosimetric study demonstrates that SMART can be applied in cases where HDR-BT is not available or ineligible with acceptable target coverage and OAR sparing. However, prospective clinical studies are needed to validate these results., (Copyright © 2023 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To report the utilization of radiation therapy in Syrian refugee patients with prostate cancer residing in Turkey., Methods and Materials: A multi-institutional retrospective review including 14 cancer centers in Turkey was conducted to include 137 Syrian refugee patients with prostate cancer treated with radiation therapy (RT). Toxicity data was scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Noncompliance was defined as a patient missing two or more scheduled RT appointments., Results: Advanced disease, defined as stage III or IV, was reported in 64.2% of patients while androgen deprivation therapy (ADT) was only administrated to 20% of patients. Conventionally fractionated RT with a median number of 44 fractions was delivered to all patients with curative intent ( n = 61) while palliative RT ( n = 76) was delivered with a median number of 10 fractions. The acute grade 3-4 toxicity rate for the entire cohort was 16%. Noncompliance rate was 42%., Conclusion: Most Syrian refugee prostate cancer patients presented with advanced disease however ADT was seldom used. Despite the low treatment compliance rate, conventional fractionation was used in all patients. Interventions are critically needed to improve screening and increase the use of standard-of-care treatment paradigms, including hypofractionated RT and ADT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Eren, Kilic, Eren, Kaplan, Teke, Kutuk, Bicakci, Hathout, Moningi, Orio, Atalar and Sayan.)

Radiation oncology is a field of medicine that has been rapidly growing with advances in technology, radiobiology, treatment algorithms and quality of life of modern radiotherapy over the last century. In the context of these advances, it is critical to be aware of the role of the young radiation oncologists and enable them to discover new perspectives. For this purpose, "The Young Radiation Oncologists Group" (GROG) has been established by the Turkish Society for Radiation Oncology (TROD), a subgroup which has focused on the professional developments, early career and integrating into the TROD family while supporting education and innovative research of young radiation oncologists. The purpose of this paper was to outline the structure and responsibilities of GROG and its scientific and social activities within TROD and in its own right., Competing Interests: Conflict of interest None declared., (© 2023 Greater Poland Cancer Centre.)

Lymphoid neoplasia derived from mucosa-associated lymphoid tissue (MALT; also abbreviated as MALToma) is most commonly seen in the stomach. Radiotherapy (RT) is indicated in early-stage disease as a standard of care. With the advent of RT techniques, large field irradiation was replaced by involved site and involved field approaches. Magnetic resonance imaging-guided online adaptive RT (MRgRT) has the advantage of better soft tissue visualization, adaptive planning before each fraction, and online tumor tracking during treatment; hence, it could be a safe and effective choice for gastric MALToma patients. Herein, we investigated the interfractional changes in target and the impact of MRgRT on daily dosimetry in a gastric MALToma case. A patient diagnosed with MALToma who failed to respond to antibacterial treatment was referred to our clinic for RT. He was found to be suitable for MRgRT. We treated the patient with MRgRT in 20 fractions to a total dose of 30 Gy. Reoptimized adaptive plans were generated before each fraction since the coverages of the original plan were inadequate in each fraction. The patient showed good compliance and tolerated the treatment well. To our knowledge, this is the first documented case of a gastric MALToma treated with MRgRT. MRgRT is safe and feasible for this patient group with improved target coverage using small planning target volume margins. Without online adaptive planning, the target coverages would be inadequate and we would risk surrounding tissues to get higher doses., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Dincer et al.)

Background: To assess and report clinical outcomes after carotid sparing intensity-modulated radiotherapy for early stage laryngeal cancer., Methods: We retrospectively analyzed 201 patients with early stage glottic laryngeal cancer treated with carotid sparing intensity-modulated radiotherapy (IMRT)/volumetric modulated arc therapy (VMAT) techniques in six TROD centers., Results: After a median follow-up of 31 months the actuarial 1- and 3-year local and locoregional control rates were 99.4% and 94.7%, 98.4% and 93%, respectively. T classification, anterior commissure involvement, IMRT technique, and type of fractionation were not found to be prognostic for local control. Overall, eight patients had lost their organ function due to recurrence or toxicity. Grade 3 and 4 acute laryngeal edema was seen in eight (4%) and one (0.5%) of patients, respectively. Grade 3 and 4 late laryngeal edema developed in two (1%) and one patient (0.5%), respectively., Conclusion: Oncologic outcomes of patients treated with carotid sparing IMRT were excellent; comparable with historical series, with acceptable side effects. Longer follow-up is needed to estimate long term effect on stroke., (© 2022 Wiley Periodicals LLC.)

For over 10 years, the Syrian conflict has caused millions of people to leave their homeland, causing one of the biggest refugee crises in modern history. Considering its prevalence, cancer is an important care burden among Syrian refugees. Radiation therapy is one of the essential parts of cancer treatment, and radiation oncology departments must guarantee optimal cancer treatments even in such a challenging setting when patients are displaced forcefully from their homes. National and institutional measures are highlighted in this manuscript to provide suggestions for the delivery of care during refugee crises. There are two issues creating barriers to serving refugee populations: the loss of access to their original care records in Syria for those with a previous diagnosis of cancer referred for continuation of radiation therapy or reirradiation, and the effect of acute radiation therapy toxicity on treatment compliance., (© 2022 The Authors.)

Background: The objective of this study was to determine how long to wait in locally advanced rectal tumor (LARC) patients who receive total neoadjuvant therapy (TNT) and achieve a clinical complete response (cCR), and to identify the clinical parameters that affect the waiting period for the watch-and-wait strategy (W &W)., Materials and Methods: The data of patients who achieved cCR between February 2015 and June 2020 were examined retrospectively. The week in which patients with cCR at the end of TNT achieved clearance was determined by reanalyzing recorded endoscopy video images. In the assessment at the time of the initial diagnosis, tumor characteristics, such as digital rectal examination findings, MRI stage, location with respect to the puborectalis muscle, annularity, and tumor size, were recorded prospectively., Results: A total of 54 patients were included in this study. According to the MRI-T stage, 14 cases were cT3a, 22 were cT3b, and 18 were cT3c-T4. Forty-four percent of the cases achieved cCR at 8-10 weeks, 19% at 12-16 weeks, 20% at 16-22 weeks, and 17% at 20-26 weeks. Patients with tumors that were early MRI-T stage (cT3a), negative clinical circumferential resection margin, mobile, small (≤4 cm), located above the puborectalis muscle and showed <180 degrees annularity achieved cCR significantly earlier than those with other tumors (p<0.05)., Conclusion: In this study, cCR was achieved in less than half (44%) of the cases during the 8-10 week waiting period. In the W&W strategy, the initial assessment for cCR seems insufficient, and we may need to wait up to 26-30 weeks, especially in patients with advanced-stage tumors.

Background: Access to cancer care is a problem that continues to plague refugees displaced from their home countries. The turbulent political crisis in Syria, which has led to millions of refugees seeking asylum in Turkey, merits further attention. We aimed to study the rate of utilization of radiation therapy among Syrian refugees with cancer living in Turkey in an attempt to identify the contributing factors predictive of non-compliance with prescribed RT., Methods: In this retrospective review of 14 institutional databases, Syrian refugee patients in Turkey with a cancer diagnosis from January 2015 to December 2019 who were treated with RT were identified. The demographic data, treatment compliance rates, and toxicity outcomes in these patients were surveyed. Variable predictors of noncompliance such as age, sex, diagnosis, treatment length, and toxicity were studied. The association between these variables and patient noncompliance was determined., Results: We identified 10,537 patients who were diagnosed with cancer during the study period, of whom 1010 (9.6%) patients were treated with RT. Breast cancer (30%) and lung cancer (14%) were the most common diagnoses with up to 68% of patients diagnosed at an advanced stage (Stage III, IV). 20% of the patients were deemed noncompliant. Treatment with concurrent chemoradiotherapy (OR 1.61, 95% CI 1.06-2.46, p = 0.023) and living in a refugee camp (OR 3.62, 95% CI 2.43-5.19, p < 0.001) were associated with noncompliance. Age, sex and treatment length were not significantly associated with noncompliance., Conclusions: Noncompliance with radiotherapy among Syrian refugees in Turkey remains an area of concern with a multitude of factors contributing to these alarming numbers. Further studies to better ascertain the finer nuances of this intricately complex problem and a global combination of efforts can pave the way to providing a solution., (© 2022. The Author(s).)

Purpose: Randomized data show a survival benefit of stereotactic ablative body radiation therapy in selected patients with oligometastases (OM). Stereotactic magnetic resonance guided adaptive radiation therapy (SMART) may facilitate the delivery of ablative dose for OM lesions, especially those adjacent to historically dose-limiting organs at risk, where conventional approaches preclude ablative dosing., Methods and Materials: The RSSearch Registry was queried for OM patients (1-5 metastatic lesions) treated with SMART. Freedom from local progression (FFLP), freedom from distant progression (FFDP), progression-free survival (PFS), and overall survival (LS) were estimated using the Kaplan-Meier method. FFLP was evaluated using RECIST 1.1 criteria. Toxicity was evaluated using Common Terminology Criteria for Adverse Events version 4 criteria., Results: Ninety-six patients with 108 OM lesions were treated on a 0.35 T MR Linac at 2 institutions between 2018 and 2020. SMART was delivered to mostly abdominal or pelvic lymph nodes (48.1%), lung (18.5%), liver and intrahepatic bile ducts (16.7%), and adrenal gland (11.1%). The median prescribed radiation therapy dose was 48.5 Gy (range, 30-60 Gy) in 5 fractions (range, 3-15). The median biologically effective dose corrected using an alpha/beta value of 10 was 100 Gy 10 (range, 48-180). No acute or late grade 3+ toxicities were observed with median 10 months (range, 3-25) follow-up. Estimated 1-year FFLP, FFDP, PFS, and OS were 92.3%, 41.1%, 39.3%, and 89.6%, respectively. Median FFDP and PFS were 8.9 months (95% confidence interval, 5.2-12.6 months) and 7.6 months (95% confidence interval, 4.5-10.6 months), respectively., Conclusions: To our knowledge, this represents the largest analysis of SMART using ablative dosing for non-bone OM. A median prescribed biologically effective dose of 100 Gy 10 resulted in excellent early FFLP and no significant toxicity, likely facilitated by continuous intrafraction MR visualization, breath hold delivery, and online adaptive replanning. Additional prospective evaluation of dose-escalated SMART for OM is warranted., (© 2022 The Author(s).)

Lattice Radiotherapy (LRT) is a technique in which heterogeneous doses are delivered to the target so large tumors can have optimal doses of radiation without compromising healthy tissue sparing. To date, case reports and case series documented its application for bulky tumors mainly in the pelvic region. LRT not only provides dosimetric advantages but also promotes tumor control by triggering some radiobiological and immunological pathways. We report two cases of giant liver metastases for whom other treatment options were not suitable. We treated both patients with Magnetic Resonance Image-Guided Radiotherapy (MRgRT) with online adaptive LRT (OALRT) technique. Adaptive plans were generated before each fraction. Tumors were observed to have regressed interfractionally so the location and number of spheres were adapted to tumor size and daily anatomy of the surrounding organs at risk (OAR). Both patients had good treatment compliance without any Grade 3+ side effects. They are both under follow-up and report improvement. By reporting the first application of OALRT by using MRgRT in liver metastases, we show that MRgRT is a promising modality for LRT technique with better target and OAR visualization as well as online adaptive planning before each fraction according to the daily anatomy of the patient., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Dincer et al.)

Hepatocellular carcinoma (HCC) presenting with tumor thrombus (TT) and inferior vena cava (IVC)/right atrium (RA) infringement point to an advanced-stage disease that is deemed inoperable. Stereotactic body radiotherapy is an emerging treatment option for this group of patients with promising outcomes in recent studies that are comparable to conventional treatment methods, namely, transarterial chemoembolization and transarterial radioembolization. Here, we report a case of HCC with RA extension through the IVC. The patient was referred to our clinic for treatment options, and he was found suitable for magnetic resonance imaging-guided radiotherapy (MRgRT). We treated the patient with MRgRT in five fractions to a total dose of 40 Gray. The tumor was tracked during the treatment sessions, and adaptive treatment planning was performed before each fraction. The patient tolerated the treatment well with no acute grade 3-4 toxicities. The last follow-up showed that the patient had a complete biochemical response and is now a candidate for an orthotopic liver transplant. To our knowledge, this report is the first to document the MRgRT treatment of an HCC with TT and RA extension. MRgRT is safe and feasible for this patient group and can be an effective bridging therapy for liver transplants., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Dincer et al.)