Current studies on salvage radiotherapy (sRT) for biochemically recurrent prostate cancer after radical prostatectomy investigate timing, dose-escalation and androgen deprivation therapy (ADT) for recurrent prostate cancer. These approaches could either be limited by radiation-related susceptibility of the anastomosis or by suspected side-effects of ADT. A phase II protocol was developed to investigate the benefit and tolerability of regional hyperthermia with moderately dose-escalated sRT. The study hypothesis is that hyperthermic sRT is a safe and feasible salvage treatment modality. The primary endpoint is safety measured by frequency of grade 3+ genitourinary (GU) and gastrointestinal (GI) adverse events (AE) according to Common Toxicity Criteria (CTC) version 4. Feasibility is defined by number of hyperthermia treatments (n ≥ 7) and feasibility of sRT according to protocol. Target volume delineation is performed according to the EORTC guidelines. sRT is administered with single doses of 2 Gy 5×/week to a total dose of 70 Gy to the prostate bed, or alternatively the total dose only to the area of highest risk and a lower dose to the remaining prostate bed using a simultaneous boost (SIB) technique. Regional hyperthermia is given 2×/week to a total of 10 treatments. German centres participate in the phase II trial using intensity modulated RT (IMRT), volumetric modulated arc technique (VMAT) or tomotherapy. The initiating centres were participants of the SAKK 09/10 study, where the same patient criteria and target volume definition (mandatory successful performed dummy run) were applied insuring a high standardisation of the study procedures.~The introduced phase II study implements modern sRT and regional hyperthermia. If the phase II study is found to be safe and feasible, a multicenter phase III study might be performed to test whether the addition of regional hyperthermia to dose-intensified sRT improves biochemical control.
The combination of regional hyperthermia and salvage radiotherapy is being tested in patients with biochemically recurrent prostate cancer after radical prostatectomy.