Intensity-Modulated Radiotherapy with Regional Hyperthermia for High-Risk Localized Prostate Carcinoma

SIMPLE SUMMARY: Several randomized controlled trials have shown that concurrent use of deep regional hyperthermia and radiotherapy results in a significant increase in local control of cervical and rectal cancer. Intensity-modulated radiotherapy (IMRT) plus androgen deprivation therapy (ADT) has recently become standard treatment for high-risk localized prostate carcinoma; however, as there is room for improvement in outcomes, we have been using hyperthermia to improve the effect of IMRT. This retrospective analysis shows that addition of regional hyperthermia to IMRT plus ADT is a promising approach as it improves clinical outcomes with acceptable toxicity. Importantly, a higher thermal dose was significantly correlated with better biochemical disease-free survival. Further investigations, including prospective trials with detailed treatment protocols, are needed. ABSTRACT: Background: The purpose of this study was to evaluate the efficacy and toxicity of adding regional hyperthermia to intensity-modulated radiotherapy (IMRT) plus neoadjuvant androgen deprivation therapy (ADT) for high-risk localized prostate carcinoma. Methods: Data from 121 consecutive patients with high-risk prostate carcinoma who were treated with IMRT were retrospectively analyzed. The total planned dose of IMRT was 76 Gy in 38 fractions for all patients; hyperthermia was used in 70 of 121 patients. Intra-rectal temperatures at the prostate level were measured to evaluate thermal dose. Results: Median number of heating sessions was five and the median total thermal dose of CEM43T90 was 7.5 min. Median follow-up duration was 64 months. Addition of hyperthermia to IMRT predicted better clinical relapse-free survival. Higher thermal dose with CEM43T90 (>7 min) predicted improved biochemical disease-free survival. The occurrence of acute and delayed toxicity ≥Grade 2 was not significantly different between patients with or without hyperthermia. Conclusions: IMRT plus regional hyperthermia represents a promising approach with acceptable toxicity for high-risk localized prostate carcinoma. Further studies are needed to verify the efficacy of this combined treatment.