Interstitial hyperthermia of the prostate in combination with brachytherapy : An evaluation of feasibility and early tolerance

A retrospective study to evaluate the feasibility and toxicity of interstitial hyperthermia (IHT) combined with high-dose-rate (HDR) brachytherapy as the initial treatment for low- and intermediate-risk prostate cancer, and as a salvage therapy in previously irradiated patients with local recurrence.

Between 18 December 2008 and 5 September 2012, 73  prostate cancer patients were treated with interstitial HDR brachytherapy of the prostate combined with IHT. In 54 patients this was the initial therapy for prostate cancer, while the other 19 were treated for local recurrence after previously undergoing external beam radiotherapy (EBRT). Toxicity for the organs of the genitourinary system and rectum was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v. 4.03 within 3 months after treatment.

Median follow-up was 15 months (range 3-46). The combination of HDR brachytherapy and IHT was well tolerated. The toxicity profile was similar to that of HDR brachytherapy when not combined with hyperthermia. The most common minor complications were urinary frequency (grade 1: 37 %; grade 2: 22 %), nocturia (three times per night: 29 %; four- or more times per night: 20 %) and transient weakening of the urine stream (grade 1: 36 %; grade 2: 11 %). No early rectal complications were observed in the patient group and the severity of genitourinary toxicity was only grade 1-2.

Early tolerance of IHT in combination with HDR brachytherapy is good. Further prospective clinical studies should focus on the effects of combining IHT with HDR brachytherapy and the influence of this adjuvant therapy on biochemical disease-free survival, local control and overall survival.