Preliminary Results of the American Brachytherapy Society Survey of Practice Patterns for Vaginal Brachytherapy for Postoperative Endometrial Cancer

Abstract

ControlNumber: 5 Category: Endometrial Preliminary Results of the American Brachytherapy Society Survey of Practice Patterns for Vaginal Brachytherapy for Postoperative Endometrial Cancer Matthew Harkenrider, MD, Beth Erickson, MD, Akila Viswanathan, MD, MPH, Surbhi Grover, MD, William Small, MD. Department of Radiation Oncology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA; Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Radiation Oncology, Dana-Farber Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA; Department of Radiation Oncology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA. Purpose: To provide preliminary results of the current practice patterns for the treatment of postoperative endometrial cancer with a focus on vaginal brachytherapy (VB). Materials and Methods: In January 2014, a 42-item survey was electronically mailed twice 2 weeks apart to 1598 members of the American Brachytherapy Society. Practice patterns of brachytherapy for cervical cancer were jointly surveyed. Practitioners who do not deliver VB or had not treated in the recent 12 months were excluded from the remainder of the survey. Only users reporting use of high dose rate (HDR) answered HDR questions, and low dose rate (LDR) users answered LDR questions. Responses were tabulated to determine the relative frequency distribution. Results: Upon preliminary analysis of 1598 surveys emailed, 114 were completed for a response rate of 7.1%. Of those who had responded, 109 (96%) treated patients with VB and 108 (95%) performed VB in the recent 12 months. 54% of responders work in an academic hospital-based facility. 83% make treatment decisions based on whether a lymph node dissection was performed and 65% based on the number of nodes removed. HDR is delivered by 98%, LDR 2%, and PDR 0%. The most common prescription length of the vagina is 4cm (48%) and most common fractional length of the vagina is the proximal 1⁄2 (65%). 25% place radio-opaque markers at the vaginal apex. 75% always use the same applicator. Doses to normal pelvic structures are reported by 78%. Aggressive histologies (clear cell/ UPSC) are treated with VB without EBRT by 66%, most of whom (77%) do so only if in combination with chemotherapy. For HDR responders, the most common applicators are single channel cylinder (81%) and multi-channel cylinder (15%). 3D planning is used by 80%, and 71% of those do so for the first fraction only. About half (49%) optimize the plan to the target and/or normal structures. 45% take localization X-rays prior to each treatment, and 83% adjust positioning as needed. 57% prescribe to 0.5cm depth with the most common prescription being 7 Gy x3 fractions (64%). 27% prescribe to vaginal surface with the most common prescription being 6 Gy x5 fractions (45%). If combined with EBRT, the most common prescriptions are 5.0-5.5 Gy x3 fractions (55%) to 0.5cm depth and 6 Gy x3 fractions (39%) to the surface. 47% deliver 2 fractions per week while 36% deliver 1 per week and 17% deliver 3 or more per week. 72% place optimization points at both the apex and lateral vaginal mucosa and 99% perform QA secondary check. Conclusions: VB is a common adjuvant therapy for endometrial cancer patients. HDR continues to be the most common modality. Fractionation and planning processes are variable, but in general, they align with ABS recommendations. Final updates will be presented at the time of the meeting. Abstract.ControlNumber: 8ControlNumber: 8 Category: Endometrial Effect Dose Treatment Planning Brachytherapy for Result Radiotherapy of Endometrial Cancer Vladimir G. Turkevich, MD. Radiation oncology and radiology, N.N.Petrov Research Institute of Oncology, Saint-Petersburg, Russian