Background: To respond to the pandemic, many societies, including the American Society for Radiation Therapy (ASTRO), the United Kingdom’s National Institute for Health and Care Excellence (NICE), and the Philippine Radiation Oncology Society (PROS), recommended guidelines to allow for continued safe delivery of oncologic services. Yet, the delivery of radiotherapy during the COVID-19 pandemic remains a challenge. Objective: To describe the situation of radiotherapy delivery in Metro Manila (NCR) during the COVID-19-related quarantine. Specifically, the objectives were to determine: (1) how the radiotherapy providers implemented the recommended changes, (2) if these implemented changes allowed the hospitals to operate with pre-COVID capacities, and (3) the causative factors of treatment interruptions if these were present. Additionally, in the face of treatment interruptions, the authors sought to put forth recommendations to decrease treatment interruptions. Methods: Investigators gathered data on the prevailing situation of RT services in their respective institutions during the strictest period of quarantine — Enhanced Community Quarantine (ECQ). Patients aged 18-70 years old who missed at least one fraction during the ECQ from March 16 – April 15, 2020, were invited to participate in a phone survey to determine factors contributing to treatment interruptions. Results: All the institutions implemented global recommendations to adapt to the pandemic, including infection control measures, telemedicine, and modification of RT plans. Despite this, most institutions had increased treatment interruptions during ECQ. The percentage of patients with interruptions was also much higher during the ECQ (66.37%) than during the pre-COVID month (30.56%). Among 142 patients unable to continue treatment, there were no significant differences in demographic variable and oncologic profile rates. The majority were more worried about getting COVID-19 than missing RT. The most common factor for treatment interruptions was transportation, followed by fear of getting COVID-19. Conclusion Compliance with global recommendations is not enough to ensure that the patients who require radiotherapy will receive it. Based on institutional and patient results, the causative factors of interruptions included suspension of services, lack of transportation, and anxiety of patients and staff. Especially in low-resource settings, recommendations are to use available resources as efficiently as possible by having an organized referral system, providing transportation or nearby accommodation for patients and staff, and communicating effectively to reassure patients that radiotherapy can be continued safely.
radiotherapy ; radiation therapy ; radiation oncology

OBJECTIVES: Radiation therapy is a main method for female pelvic malignancies, which can cause some adverse reactions, such as radiation proctitis (RP). The incidence of RP is highly positively correlated with radiation dose. There is an urgent need for a scientific method to accurately predict the occurrence of RP to help doctors make clinical decisions. In this study, based on the clinical data of female pelvic tumor patients and dosimetric parameters of radiotherapy, the random forest method was used to screen the hub features related to the occurrence of RP, and then a machine learning algorithm was used to construct a risk prediction model for the occurrence of RP, in order to provide technical support and theoretical basis for the prediction and prevention of RP. METHODS: A total of 100 female patients with pelvic tumors, who received static three-dimensional conformal intensity-modulated radiation therapy in the Department of Radiation Oncology of the Affiliated Hospital of Xiangnan University from January 2019 to December 2020, were retrospectively collected, and their clinically relevant data and radiotherapy planning system data were collected. During radiotherapy and 18 months after radiotherapy, 35 cases developed RP (RP group), and the remaining 65 cases had no RP (non-RP group). The clinical and dosimetric characteristics of patients were ranked by the importance of random forest algorithm, and the independent prognostic characteristics associated with the occurrence of RP were selected for machine learning modeling. A total of 6 machine learning algorithms including support vector machines, random forests, logistic regression, lightweight gradient boosting machines, Gaussian naïve Bayes, and adaptive enhancement were used to build models. The performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score. Finally, the random forest model was determined as the prediction model, and the calibration curve and decision curve of the prediction model were drawn to evaluate the accuracy and clinical benefit of the model. RESULTS: The parameters for random forest prediction model in the training set were as follow: AUC, 1.000, accuracy, 0.988, sensitivity, 1.000, specificity, 1.000, positive predictive value, 1.000, negative predictive value, 0.981, and F1 score, 1.000. In validation set, AUC was 0.713, accuracy was 0.640, sensitivity was 0.618, specificity was 0.822, positive predictive value was 0.500, negative predictive value was 0.656, and F1 score was 0.440. Random forest showed high predictive performance. Moreover, the Brief of the calibration curve for the prediction model was 0.178, the prediction accuracy was high, and the decision curve showed that the prediction model could benefit clinically. CONCLUSIONS Based on the clinical and dosimetric parameters for the female pelvic tumor patients, the prediction model of radiation proctitis constructed by random forest algorithm has high predictive ability and strong clinical usability.
Bayes Theorem ; Female ; Humans ; Machine Learning ; Pelvic Neoplasms/radiotherapy* ; Proctitis/etiology* ; Radiation Oncology ; Retrospective Studies

PURPOSE: The purpose of this study was to evaluate the risk of central nervous system (CNS) failure in Korean patients with human epidermal growth factor receptor 2 (HER2)-enriched breast cancer treated with surgery followed by postoperative radiotherapy (RT). METHODS: A total of 749 patients from eight institutions were enrolled in this study. All of them underwent surgery followed by postoperative RT from 2003 to 2011; 246 (32.8%) received neoadjuvant chemotherapy and 649 (81.7%) received adjuvant chemotherapy. Adjuvant trastuzumab was administered to 386 patients (48.6%). RESULTS: The median follow-up duration was 84 (range, 8–171) months. The 7-year disease-free and overall survival rates were 79.0% and 84.2%, respectively. On multivariate analysis, mastectomy, nodal involvement, and presence of lymphatic invasion were correlated with poor overall survival (p = 0.004, 0.022, and 0.011, respectively), whereas T stage and lymphatic invasion were associated with disease-free survival (p = 0.018 and 0.005, respectively). Regarding CNS failures, 30 brain metastases, 2 leptomeningeal metastases, and 8 brain and leptomeningeal metastases were noted. The 7-year CNS relapse-free survival rates in patients receiving and not receiving trastuzumab were 91.2% and 96.9%, respectively (p = 0.005). On multivariate analysis, the administration of adjuvant trastuzumab was the only prognostic factor in predicting a higher CNS failure rate (hazard ratio, 2.260; 95% confidence interval, 1.076–4.746; p = 0.031). CONCLUSION: Adjuvant trastuzumab was associated with higher CNS failure rate in Korean patients with HER2-enriched breast cancer. Close monitoring and reasonable approaches such as CNS penetrating HER2 blockades combined with the current standard therapy could contribute to improving intracranial tumor control and quality of life in patients with CNS metastasis from HER2-enriched breast cancer.
Brain ; Breast Neoplasms ; Breast ; Central Nervous System Neoplasms ; Central Nervous System ; Chemotherapy, Adjuvant ; Disease-Free Survival ; Drug Therapy ; Follow-Up Studies ; Humans ; Mastectomy ; Multivariate Analysis ; Neoplasm Metastasis ; Quality of Life ; Radiation Oncology ; Radiotherapy ; Receptor, Epidermal Growth Factor ; Retrospective Studies ; Survival Rate ; Trastuzumab

PURPOSE: The aim of this retrospective study was to investigate the use of a radiopaque tissue fiducial marker (TFM) in the treatment of prostate cancer patients who undergo post-prostatectomy radiotherapy (PPRT). TFM safety, its role and benefit in quantifying the set-up uncertainties in patients undergoing PPRT image-guided radiotherapy were assessed. MATERIALS AND METHODS: A total of 45 consecutive PPRT patients underwent transperineal implantation of TFM at the level of vesicourethral anastomosis in the retrovesical tissue prior to intensity-modulated radiotherapy. Prostate bed motion was calculated by measuring the position of the TFM relative to the pelvic bony anatomy on daily cone-beam computed tomography. The stability and visibility of the TFM were assessed in the initial 10 patients. RESULTS: No postoperative complications were recorded. A total of 3,500 images were analysed. The calculated prostate bed motion for bony landmark matching relative to TFM were 2.25 mm in the left-right, 5.89 mm in the superior-inferior, and 6.59 mm in the anterior-posterior directions. A significant 36% reduction in the mean volume of rectum receiving 70 Gy (rV₇₀) was achieved for a uniform planning target volume (PTV) margin of 7 mm compared with the Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group recommended PTV margin of 10 mm. CONCLUSION: The use of TFM was safe and can potentially eliminate set-up errors associated with bony landmark matching, thereby allowing for tighter PTV margins and a consequent favourable reduction in dose delivered to the bladder and rectum, with potential improvements in toxicities.
Clothing ; Cone-Beam Computed Tomography ; Fiducial Markers ; Humans ; New Zealand ; Postoperative Complications ; Prostate ; Prostatectomy ; Prostatic Neoplasms ; Radiation Oncology ; Radiotherapy ; Radiotherapy, Image-Guided ; Radiotherapy, Intensity-Modulated ; Rectum ; Retrospective Studies ; Urinary Bladder

PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.
Brain ; Carcinoma, Non-Small-Cell Lung ; Compliance ; Hippocampus ; Lung Neoplasms ; Neoplasm Metastasis ; Prospective Studies ; Radiation Oncology ; Radiotherapy

PURPOSE: The benefit of post-mastectomy radiation therapy (PMRT) in patients with breast cancer who achieve ypN0 following neoadjuvant chemotherapy (NAC) has not yet been established. This study aimed to identify the role of PMRT in patients who achieve ypN0 according to molecular subtype. METHODS: We identified patients initially suspected with axillary disease who achieved ypN0 following NAC. From 13 institutions of the Korean Radiation Oncology Group between 2005 and 2011, a total of 189 patients were included in the analysis. Effects of PMRT on loco-regional control (LRC), disease-free survival (DFS), and overall survival (OS) were evaluated for different molecular subtypes. RESULTS: In all patients, the prognostic effect of PMRT on LRC, DFS, or OS was not significant. Subgroups analysis showed that the effect of PMRT on LRC was different according to molecular subtype (p for interaction = 0.019). PMRT was associated with greater LRC in the luminal subtype (p = 0.046), but not in other subtypes. CONCLUSION: In patients who achieve ypN0 following NAC and mastectomy, PMRT shows no additional survival benefits for any molecular subtype.
Breast Neoplasms ; Disease-Free Survival ; Drug Therapy ; Humans ; Mastectomy ; Neoadjuvant Therapy ; Phenobarbital ; Radiation Oncology ; Radiotherapy

Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.
Radiation Oncology ; Radiotherapy, Conformal

In 2017, 10 topics were selected as major clinical research advances in gynecologic oncology. For cervical cancer, efficacy and safety analysis results of a 9-valent human papillomavirus (HPV) vaccine and long-term impact of reduced dose of quadrivalent vaccine were updated. Brief introduction of KEYNOTE trials of pembrolizumab, a monoclonal antibody that blocks the interaction between programmed death (PD)-1 and its ligands, PD-L1 and PD-L2, followed. Tailored surveillance programs for gynecologic cancer related with Lynch syndrome and update on sentinel lymph node mapping were reviewed for uterine corpus cancer. For ovarian cancer, 5 topics were selected including poly(ADP-ribose) polymerases inhibitors and immunotherapy. The other potential practice changers covered in this review were lymphadenectomy in advanced disease, secondary cytoreductive surgery in recurrent disease, weekly dose-dense regimen for first-line chemotherapy, incorporation of bevacizumab maintenance in platinum-sensitive recurrent disease, and effect of platinum-free interval prolongation. Conflicting opinions of academic societies on periodic pelvic examination were introduced in conjunction with relevant literature review. For the field of radiation oncology, results of 2 big trials, The Postoperative Radiation Therapy in Endometrial Carcinoma-3 and Gynecologic Oncology Group-258, for endometrial cancer and recent advance in high-dose-rate brachytherapy for cervical cancer were reported. Topics for breast cancer covered adjuvant capecitabine after preoperative chemotherapy, adjuvant pertuzumab and trastuzumab in early human epidermal growth factor receptor 2-positive disease, olaparib for metastatic cancer in patients with a germline BRCA mutation, 20-year risks of recurrence after stopping endocrine therapy at 5 years, and contemporary hormonal contraception and the risk of breast cancer.
Bevacizumab ; Brachytherapy ; Breast Neoplasms ; Capecitabine ; Chemotherapy, Adjuvant ; Colorectal Neoplasms, Hereditary Nonpolyposis ; Contraception ; Drug Therapy ; Endometrial Neoplasms ; Female ; Gynecological Examination ; Humans ; Immunotherapy ; Ligands ; Lymph Node Excision ; Lymph Nodes ; Molecular Targeted Therapy ; Ovarian Neoplasms ; Poly(ADP-ribose) Polymerase Inhibitors ; Poly(ADP-ribose) Polymerases ; Radiation Oncology ; Receptor, Epidermal Growth Factor ; Recurrence ; Trastuzumab ; Uterine Cervical Neoplasms

Adjuvant radiotherapy (RT) is a well-established treatment for breast cancer. However, there is a large degree of variation and controversy in practice patterns. A nationwide survey on the patterns of practice in breast RT was designed by the Division for Breast Cancer of the Korean Radiation Oncology Group. All board-certified members of the Korean Society for Radiation Oncology were sent a questionnaire comprising 39 questions on six domains: hypofractionated whole breast RT, accelerated partial breast RT, postmastectomy RT (PMRT), regional nodal RT, RT for ductal carcinoma in situ, and RT toxicity. Sixty-four radiation oncologists from 54 of 86 (62.8%) hospitals responded. Twenty-three respondents (35.9%) used hypofractionated whole breast RT, and the most common schedule was 43.2 Gy in 16 fractions. Only three (4.7%) used accelerated partial breast RT. Five (7.8%) used hypofractionated PMRT, and 40 (62.5%) had never used boost RT after chest wall irradiation. Indications for regional nodal RT varied; ≥pN2 (n=7) versus ≥pN1 (n=17) versus ≥pN1 with pathologic risk factors (n=40). Selection criteria for internal mammary lymph node (IMN) irradiation also varied; only four (6.3%) always treated IMN when regional nodal RT was administered and 30 (46.9%) treated IMN only if IMN involvement was identified through imaging. Thirty-one (48.4%) considered omission of whole breast RT after breast-conserving surgery for ductal carcinoma in situ based on clinical and pathologic risk factors. Fifty-two (81.3%) used heart-sparing techniques. Overall, there were wide variations in the patterns of practice in breast RT in Korea. Standard guidelines are needed, especially for regional nodal RT and omission of RT for ductal carcinoma in situ.
Appointments and Schedules ; Breast Neoplasms* ; Breast* ; Carcinoma, Intraductal, Noninfiltrating ; Korea* ; Lymph Nodes ; Mastectomy, Segmental ; Patient Selection ; Practice Patterns, Physicians' ; Radiation Oncology ; Radiotherapy* ; Radiotherapy, Adjuvant ; Risk Factors ; Surveys and Questionnaires ; Thoracic Wall

OBJECTIVE: To determine and compare treatment outcomes between cobalt-60 (Co-60) and iridium-192 (Ir-192) high dose rate (HDR) brachytherapy in stage IB2–IIIB cervical cancer patients at Department of Radiology, Faculty of Medicine Vajira Hospital, Navamindrahiraj University. METHODS: A retrospective cohort study of patients diagnosed with cervical cancer and treated with radiotherapy at the Department of Radiation Oncology, Faculty of Medicine Vajira Hospital between 2004 and 2014. Survival rate was analyzed by Kaplan-Meier method and were compared between groups with log-rank test. Multivariate analysis was performed using Cox proportional hazards model. RESULTS: A total of 480 patients with cervical cancer and treated with radiotherapy were included, 274 patients for Ir-192 group and 206 patients for Co-60 group. The 2- and 5-year disease-free survival rate in Ir-192 group were 80.4% and 73.1% and in Co-60 group were 82.5% and 74.7%, respectively (p = 0.365). Overall survival rates at 2 and 5 years were 89.4% and 77% of the Ir-192 group, and 91.6% and 81.9% in the Co-60 group, respectively (p = 0.238). The complications were primarily grade 1 or 2. Grade 3 and 4 complications were found in 13 of 274 and 7 of 206 in Ir-192 and Co-60 groups, respectively (p = 0.232). Grade and clinical stage of cancer significantly affected the survival outcome. CONCLUSION: Cervical cancer patients who were treated with HDR Co-60 brachytherapy were comparable in survival and toxicity outcomes of those with HDR Ir-192 brachytherapy. Co-60 source has lots of economic advantages over Ir-192 and hence suitable for low resource radiotherapy setting.
Brachytherapy* ; Cohort Studies ; Disease-Free Survival ; Humans ; Methods ; Multivariate Analysis ; Proportional Hazards Models ; Radiation Oncology ; Radiotherapy ; Retrospective Studies ; Survival Rate ; Uterine Cervical Neoplasms*