Radiation oncology journal最新文献

Purpose: Cardiac radioablation is a novel, non-invasive treatment for ventricular tachycardia (VT), involving a single fractional stereotactic ablative body radiotherapy (SABR) session with a prescribed dose of 25 Gy. This complex procedure requires a detailed workflow and stringent dose constraints compared to conventional radiation therapy. This study aims to establish a consistent institutional workflow for single-fraction cardiac VT-SABR, emphasizing robust plan evaluation and quality assurance.

Materials and methods: The study developed a consistent institutional workflow for VT-SABR, including computed tomography (CT) simulation, target volume definition, treatment planning, robust plan evaluation, quality assurance, and image-guided strategy. The workflow was implemented for two patients with cardiac arrhythmia. Accurate target volume definition using planning CT images and electronic anatomical mapping was critical. A four-dimensional (4D) cone-beam CT (CBCT) and breath-hold electrocardiographic gated CT images reliably detected target motion.

Results: The resulting plans exhibited a conformity index greater than 0.7 and a gradient index around G4.0. Dose constraints for the planning target volume (PTV) aimed for 95% or higher PTV dose coverage, with a maximum dose of 200% or lower. However, one case did not meet the PTV dose coverage due to the proximity of the PTV to gastrointestinal organs. Plans adhered to dose constraints for organs at risk near the heart, but meeting constraints for specific cardiac sub-structures was challenging and dependent on PTV location.

Conclusion: The plans demonstrated robustness against respiratory motion and patient positional uncertainty through a robust evaluation function. The 4D and intra-fractional CBCT were effective in verifying target motion and setup stability.

Cardiac myxomas, the most common primary cardiac tumors, are believed to originate from multipotent mesenchymal cells. Approximately 75% of myxomas occur within the left atrium, increasing the risk of systemic thromboembolic events. While typically benign, atrial myxomas can rarely metastasize to the brain, with fewer than 60 cases reported. We present a case of a 56-year-old woman with a history of left atrial myxoma who developed headaches, right arm weakness, and blurry vision three months post-cardiac surgery. Imaging showed multiple hemorrhagic brain lesions, and she was treated with whole brain radiotherapy (20 Gy/5 fractions). Four years later, she remains stable with no new lesions and has fully regained function. Currently, there is no standard management for cardiac myxoma metastases. This case highlights the potential role of radiotherapy in managing brain metastases from left atrial myxomas, suggesting a possible treatment strategy based on this case and a review of the literature.

Purpose: After primary systemic therapy (PST), agreement on the extent of locoregional therapy is lacking in breast cancer patients who convert from a node-positive to a node-negative status. The aim of this survey was to investigate radiation therapy approaches after PST according to different axillary surgical strategies and disease responses.

Materials and methods: The European Breast Cancer Research Association of Surgical Trialists developed a web-based survey containing 39 questions on locoregional management based on clinical scenarios in initially node positive breast cancer patients undergoing PST. Twelve international breast cancer societies distributed the link to breast surgeons and radiation oncologists.

Results: Responses from 349 breast specialists were recorded, 72 of whom (20.6%) were radiation oncologists from 17 countries. Nodal status at diagnosis informed the decision for postoperative regional nodal irradiation (RNI) for 44/72 (61.1%) responders. RNI in node positive patients having undergone axillary lymph node dissection (ALND) is delivered in selected cases by 30/72 (41.7%) responders and systemically recommended by 26/72 (36.1%) responders. In case of macrometastases found on ALND, 43/72 (59.7%) responders always deliver RNI. In case of micrometastases in the sentinel lymph node(s) or targeted lymph node(s), 45/72 (62.5%) responders prefer RNI to completion ALND. A majority of responders (59.7%) determine the target volume for RNI according to European Society for Radiotherapy and Oncology guidelines. Significant heterogeneity was observed regarding nodal basins and volumes of interest for dose coverage by RNI.

Conclusions: There is significant heterogeneity in radiation-therapy delivered to the axilla after PST. A more standardized approach engaging both radiation oncologists and breast surgeons will help to optimize the harm-benefit equilibrium of axillary surgery and RNI.

Purpose: Neoadjuvant radiotherapy (RT) or chemoradiotherapy (CRT) is the standard treatment for locally advanced rectal adenocarcinoma. The recent emerging data on preoperative immunotherapy as an effective therapeutic modality for mismatch repair deficient rectal carcinomas suggests that the immune system plays a significant role in tumor eradication. Although RT has been shown to stimulate anti-tumor immunity, it also leads to substantial lymphopenia, hindering the effect of immune response.

Materials and methods: We retrospectively analyzed 33 rectal adenocarcinoma patients who underwent CRT in our department, aiming to identify the effects of CRT on the peripheral blood lymphocyte counts (LC) and the potential impact of CRT-induced lymphopenia on tumor response and prognosis of patients.

Results: A statistically significant decrease in the LC of patients was observed after CRT (median values of 2,184/μL and 517/μL before and after treatment, respectively; p < 0.001). While no correlation between ypT-stage, ypN status, and LC was found, poor tumor regression grade was significantly associated with lower LC (p = 0.036). Moreover, lymphopenia was associated with poorer distant metastasis-free survival (p = 0.003). Distant metastases were documented in 0% of patients with post-CRT LC above 518/μL vs. 44.5% of patients with lower LC values.

Conclusion: Although further investigation is demanded, given the limited number of patients analyzed in the study, lymphopenia emerges as a significant adverse event that rectal adenocarcinoma patients face during treatment with neoadjuvant CRT, with subsequent implications on tumor response and prognosis. Protection of the immune system during CRT emerges as an important target for clinical research.

In this paper, we review the use of hypofractionated radiotherapy for gastrointestinal malignancies, focusing on primary and metastatic liver cancer, and recurrent rectal cancer. Technological advancements in radiotherapy have facilitated the direct delivery of high-dose radiation to tumors, while limiting normal tissue exposure, supporting the use of hypofractionation. Hypofractionated radiotherapy is particularly effective for primary and metastatic liver cancer where high-dose irradiation is crucial to achieve effective local control. For recurrent rectal cancer, the use of stereotactic body radiotherapy offers a promising approach for re-irradiation, balancing efficacy and safety in patients who have been administered previous pelvic radiotherapy and in whom salvage surgery is not applicable. Nevertheless, the potential for radiation-induced liver disease and gastrointestinal complications presents challenges when applying hypofractionation to gastrointestinal organs. Given the lack of universal consensus on hypofractionation regimens and the dose constraints for primary and metastatic liver cancer, as well as for recurrent rectal cancer, this review aims to facilitate clinical decision-making by pointing to potential regimens and dose constraints, underpinned by a comprehensive review of existing clinical studies and guidelines.

Purpose: Treatment outcomes of locally advanced rectal cancer have improved significantly in recent decades. This retrospective study aimed to assess the efficacy of neoadjuvant chemoradiotherapy (nCRT) followed by surgery in patients with T4 rectal cancer and the different outcomes between T4a and T4b patients.

Materials and methods: A total of 60 clinically T4 rectal cancer patients who underwent nCRT were included in the analysis. Patient characteristics, treatment regimens, down-staging rates, pathological response, and overall survival (OS) were evaluated.

Results: Both T4a and T4b patients experienced down-staging following nCRT (36.6% and 6.2% respectively; p = 0.021). T4a patients exhibited a higher rate of pathological complete response (pCR) than T4b patients (13.3% in T4a vs. 0% in T4b; p = 0.122). After a median follow-up of 36 months, the OS and recurrence-free survival (RFS) of T4a patients were significantly higher compared to T4b patients (hazard ratio [HR] = 2.52, 95% confidence interval [CI] 1.05-6.05, p = 0.038 for OS; HR = 2.32, 95% CI 1.09-4.92, p = 0.025 for RFS).

Conclusion: This study provides valuable insights into the effectiveness of nCRT in T4 rectal cancer patients. Although down-staging was observed in both T4a and T4b subgroups, achieving a pCR remains a challenge, particularly in T4b patients. Further research is needed to optimize treatment strategies and enhance pCR rates in T4 rectal cancer patients to improve oncologic outcomes.

Purpose: This report offers a detailed examination of the inception and current state of the Heavy-ion Therapy Center (HITC) at the Yonsei Cancer Center (YCC), setting it apart as the world's first center equipped with a fixed beam and two superconducting gantries for carbon-ion radiation therapy (CIRT).

Materials and methods: Preparations for CIRT at YCC began in 2013; accordingly, this center has completed a decade of meticulous planning and culminating since the operational commencement of the HITC in April 2023.

Results: This report elaborates on the clinical preparation for adopting CIRT in Korea. It includes an extensive description of HITC's facility layout at YCC, which comprises the accelerator and treatment rooms. Furthermore, this report delineates the clinical workflow, criteria for CIRT application, and the rigorous quality assurance processes implemented at YCC. It highlights YCC's sophisticated radiation therapy infrastructure, collaborative initiatives, and the efficacious treatment of >200 prostate cancer cases utilizing CIRT.

Conclusion: This manuscript concludes by discussing the prospective influence of CIRT on the medical domain within Korea, spotlighting YCC's pioneering contribution and forecasting the widespread integration of this groundbreaking technology.

Purpose: Cervical cancer is a significant global health issue affecting approximately 600,000 women each year. This study aimed to address the knowledge gaps surrounding the influence of treatment time parameters, including the duration of external beam radiotherapy (EBRT) to brachytherapy and overall treatment duration, on early recurrences.

Materials and methods: Details on demographics, tumor characteristics, treatment details, and outcomes in patients undergoing chemoradiation and brachytherapy for cervical cancer were collected from the medical records. Early recurrence was defined as tumor reappearance within 6 months after treatment in patients with an initial complete response. Statistical analyses included descriptive statistics chi-square tests, independent t-tests, and logistic regression.

Results: A total of 288 cervical cancer patients were included. Stage IIB was the most common stage and 93% of patients had a complete response, 4.5% partial response, and 3.1% had progressive disease at 3rd month. At 6 months, 8% experienced early. The average interval between EBRT and brachytherapy was 10.4 ± 4.2 days among the no recurrence group and 12.3 ± 4.5 days among early recurrence group. A total of 203 patients had a gap of 10 or fewer days and 123 patients had a gap of more than 10 days between EBRT and brachytherapy. Difference was observed in the overall treatment time between the two groups had significant differences (no recurrence group, 61.6 ± 11.5 days; early recurrence group, 73.8 ± 8.8 days; p < 0.001).

Conclusion: The study revealed that longer overall treatment durations were associated with a higher risk of early recurrences, highlighting the need for further investigation and optimized treatment strategies.

Purpose: Identifying comprehensively the evidence of neuroprotective effects of memantine for preserving cognitive function in brain metastasis patients receiving whole brain radiotherapy (WBRT).

Methods: We searched randomized clinical trials (RCTs) analyzing the effects of memantine to preserve cognitive function in patients with brain metastasis treated with WBRT, performed in some databases, including PubMed, Embase, and Cochrane Library. The protocol was registered at PROSPERO (CRD42023476632). We reported the selection process according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guideline. The studies were appraised by using the revised Cochrane Risk of Bias tool for randomized trials (RoB 2.0).

Results: We included three RCTs that met the eligibility criteria. No high risk of bias was found. Two articles compared WBRT + memantine to WBRT + placebo, and the other one compared hippocampal avoidance (HA)-WBRT + memantine to WBRT + memantine. There was no significant difference in characteristics among groups of treatment arms. The differences in cognitive function deterioration between treatment arms began to appear four months after initiated the treatment. The risk of cognitive failure was lower in patients receiving memantine compared to placebo. Moreover, combining HA-WBRT + memantine lowered the cognitive failure compared to standard WBRT + memantine. No article stated significant difference in quality of life (QoL) and survival outcomes in patients receiving memantine.

Conclusion: Although the evidence was still limited, memantine was reported to have the potential to mitigate radiation-induced cognitive dysfunction in patients with brain metastasis receiving WBRT. However, there was no evidence revealing the benefit of memantine for enhancing QoL and prolonging survival.