A Delphi study and International Consensus Recommendations: The use of bolus in the setting of postmastectomy radiation therapy for early breast cancer.

Bolus serves as a tissue equivalent material that shifts the 95-100% isodose line towards the skin and subcutaneous tissue. The need for bolus for all breast cancer patients planned for postmastectomy radiation therapy (PMRT) has been questioned. The work was initiated by the faculty of the European SocieTy for Radiotherapy & Oncology (ESTRO) breast cancer courses and represents a multidisciplinary international breast cancer expert collaboration to optimize PMRT. Due to the lack of randomised trials evaluating the benefits of bolus, we designed a stepwise project to evaluate the existing evidence about the use of bolus in the setting of PMRT to achieve an international consensus for the indications of bolus in PMRT, based on the Delphi method.

The use of bolus in postmastectomy radiation therapy for breast cancer: A systematic review.

PURPOSE: Post mastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and breast cancer mortality for selected patients. Bolus overcomes the skin-sparing effect of external-beam radiotherapy, ensuring adequate dose to superficial regions at risk of local recurrence (LR). This systematic review summarizes the current evidence regarding the impact of bolus on LR and acute toxicity in the setting of PMRT. RESULTS: 27 studies were included. The use of bolus led to higher rates of acute grade 3 radiation dermatitis (pooled rates of 9.6% with bolus vs. 1.2% without). Pooled crude LR rates from thirteen studies (n = 3756) were similar with (3.5%) and without (3.6%) bolus. CONCLUSIONS: Bolus may be indicated in cases with a high risk of LR in the skin, but seems not to be necessary for all patients. Further work is needed to define the role of bolus in PMRT.

Attitudes Towards Research During Residency Training: a Survey of Canadian Radiation Oncology Residents and Program Directors.

Radiation oncologists require clinical appraisal and research methodology skills, yet it is unclear how to develop these competencies during residency. We sought to attain a deeper understanding of the barriers that limit, as well as the factors that promote, engaging in research/scholarly activity during radiation oncology residency training in Canada. Following ethics approval, online surveys were circulated to all Canadian Radiation Oncology program directors and residents. Unidentifiable demographics, prior research experience, and descriptions of current research environment and barriers to engaging in research and scholarly activities were collected. Thirty-three percent (35/105) of residents and 71% (10/14) of program directors responded. Ninety-seven percent of residents, and 90% of program directors, agreed or strongly agreed that research/scholarly activity was an important part of residency training. While 66% of residents felt that there was a lack of protected time for research/scholarly activity, only 20% of program directors agreed this was a barrier (p = 0.011). While 94% of residents thought mentorship was important to completing high-quality research/scholarly activity, only 48% of respondents had a mentor. The highest barriers to completing research/scholarly activity projects were lack of protected time (for both residents and faculty), high resident clinical workload, and lack of experience in research skills. Canadian Radiation Oncology residents expressed strong enthusiasm to participate in research/scholarly activity, yet lack of protected time and competing demands were identified as major barriers. We suggest programs offer more protected time for research/scholarly activity, provide optional research methodology training, and support meaningful mentorship relationships.

Individualized Dose-Escalation of HDR Prostate Brachytherapy Implant to Decrease Required External Beam Radiation Dose: A Retrospective Feasibility Study.

PURPOSE: High-dose-rate brachytherapy (HDR-BT) is commonly combined with external beam radiation therapy (EBRT) for the treatment of localized prostate cancer. Escalating the HDR-BT dose as far as organ-at-risk (OAR) constraints allow, on a personalized basis, would allow for a reduction in EBRT dose while achieving similar total biologic equivalence. The primary objective of this study was to determine the dosimetric feasibility of escalating the HDR-BT dose from 15 Gy to 16 or 17 Gy while continuing to meet OAR constraints from the original 15 Gy plan on an individualized basis. METHODS AND MATERIALS: A total of 53 consecutive HDR-BT plans were retrospectively assessed to determine what percentage of plans could be reoptimized to deliver a dose of 16 Gy or 17 Gy, while meeting defined 15-Gy OAR constraints. Factors independently associated with dose escalation were examined. RESULTS: Thirty-nine plans (74%) and 2 plans (4%) were successfully escalated to a dose of 16 Gy and 17 Gy, respectively. Rectum V80 and urethra Dmax were independently predictive of the ability to dose escalate to 16 Gy. CONCLUSIONS: Individualized HDR-BT dose escalation beyond 15 Gy without compromising OAR constraints is dosimetrically feasible. This approach could allow for a corresponding reduction of EBRT fractions (ie, from 15 to 12 fractions) and would be beneficial in terms of resource savings for departments, convenience for patients, and potentially better tolerance of treatment with the expected reduction in biologically equivalent doses to OARs. A clinical trial is being developed to investigate the efficacy and tolerance of personalized HDR-BT/EBRT dose fractionation for localized intracapsular prostate cancer.