Patterns of care for prostate cancer radiotherapy-results from a survey among German-speaking radiation oncologists

Background Emerging moderately hypofractionated and ultra-hypofractionated schemes for radiotherapy (RT) of prostate cancer (PC) have resulted in various treatment options. The aim of this survey was to evaluate recent patterns of care of German-speaking radiation oncologists for RT of PC. Methods We developed an online survey which we distributed via e-mail to all registered members of the German Society of Radiation Oncology (DEGRO). The survey was completed by 109 participants between March 3 and April 3, 2020. For evaluation of radiation dose, we used the equivalent dose at fractionation of 2 Gy with alpha/beta = 1.5 Gy, equivalent dose (EQD2 [1.5 Gy]). Results Median EQD2(1.5 Gy) for definitive RT of the prostate is 77.60 Gy (range: 64.49-84.00) with median single doses (SD) of 2.00 Gy (range: 1.80-3.00), while for postoperative RT of the prostate bed, median EQD2(1.5 Gy) is 66.00 Gy (range: 60.00-74.00) with median SD of 2.00 Gy (range: 1.80-2.00). For definitive RT, the pelvic lymph nodes (LNs) are treated in case of suspect findings in imaging (82.6%) and/or according to risk formulas/tables (78.0%). In the postoperative setting, 78.9% use imaging and 78.0% use the postoperative tumor stage for LN irradiation. In the definitive and postoperative situation, LNs are irradiated with a median EQD2(1.5 Gy) of 47.52 Gy with a range of 42.43-66.00 and 41.76-62.79, respectively. Conclusion German-speaking radiation oncologists' patterns of care for patients with PC are mainly in line with the published data and treatment recommendation guidelines. However, dose prescription is highly heterogenous for RT of the prostate/prostate bed, while the dose to the pelvic LNs is mainly consistent.