Hypofractionated simultaneous integrated boost (IMRT-SIB) with pelvic nodal irradiation and concurrent androgen deprivation therapy for high-risk prostate cancer: results of a prospective phase II trial

Abstract

Objective The approach for treating high-risk prostate cancer still presents different unresolved issues. We report the safety and efficacy of a radiation therapy strategy based on the combination of moderate hypofractioned simultaneous integrated boost (SIB) and Image Guidance. Materials and methods In this phase II trial of patients with high-risk prostate cancer, Image Guided SIB-IMRT plans (Simultaneous Intensity Modulated -Intensity Modulated Radiotherapy) were delivered between 2009 and 2012. All patients enrolled (41) received in 25 fractions a total dose of 67.5 Gy (2.7 Gy/fraction) to the prostatic volume, 56.25 Gy (2.25 Gy/ fraction) to the seminal vescicles, and 50 Gy (2.0 Gy/fraction) to the pelvic lymph nodes (LN) chains with concurrent androgen deprivation therapy (ADT). The image-guided radiotherapy (IGRT) procedure was performed using three gold seeds. RTOG late gastrointestinal and genitourinary toxicities and 6-year biochemical relapse-free survival (BRFS) were assessed in combination of their statistical correlation with clinical factors and dosimetric parameters. Results Rate of late genitourinary toxicity grade 2 was 9.8%, while rates of late gastrointestinal toxicity were 14.6% and 2.4%, for grade 1 and 2, respectively. Diabetes and maximum doses to rectum appeared to be statistically relevant risk factors for late rectal toxicity. Five-year BRFS was 95.1%. Conclusions In our study, we observed positive results in terms of toxicity and good efficacy in a cohort of high-risk prostate cancer patients treated with a multimodality therapy approach comprising hypofractionation, irradiation of pelvic nodes (common iliac nodes included), and concurrent ADT. These favorable results may merit further investigation in a phase III randomized trial to confirm that whole pelvic radiation therapy (WPRT) combined with moderate hypofractionation and ADT could be performed safely and effectively.

Neoadjuvant chemoradiotherapy delivered with helical tomotherapy under daily image guidance for rectal cancer patients: efficacy and safety in a large, multi-institutional series

“…The interest of the SIB is that improves the dosimetry of the treatment plan, could shorten the treatment time and it could allow the reduction of the toxicity of the treatments. All these data on the SIB in the treatment of rectal cancer patients confirm the interest of this approach also in this clinical setting, as it has been already shown in other tumor sites (Lupattelli et al 2017 ; Franco et al 2014 , 2015 , 2016 , 2018 ; But-Hadzic et al 2016 ; De Rose et al 2018 ; Chatterjee et al 2019 ; Magli et al 2018 ).…”

Moderately Hypofractionated Intensity Modulated Radiation Therapy with Simultaneous Integrated Boost for Prostate Cancer: Five-Year Toxicity Results from a Prospective Phase I/II Trial

“…While this technique for treating pelvic nodes was rst pioneered in the RTOG 0529 trial in 2005 in the setting of anal cancer 17 , our trial was one of few to include SIB of pelvic nodes in the prostate cancer setting and is one of only three trials so far with median follow up of 5 years or longer. [18][19][20] Although the bene t of pelvic nodal treatment has yet to be established, it may play a larger role in the management of prostate cancer as recent RTOG clinical trials continue to accrue and completed trials' data mature. 21,22 It would be expected to see higher rates of late GI toxicity in the nodal treatment cohort, however we instead saw a trend towards less toxicity.…”

Moderately Hypofractionated Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost for Prostate Cancer: Five-Year Toxicity Results From a Prospective Phase I/II Trial

“…A unique feature of the current trial is its inclusion of pelvic nodal treatment in a subset of patients utilizing a SIB technique. While this technique for treating pelvic nodes was first pioneered in the RTOG 0529 trial in 2005 in the setting of anal cancer (23), our trial was one of few to include SIB of pelvic nodes in the prostate cancer setting and is one of only three trials so far with median follow up of 5 years or longer (24)(25)(26).…”

“…While our rates of GU toxicities are comparable, our rate of GI toxicity is numerically lower and could be explained by larger PTV expansions or complete SV coverage in the Di Muzio trial. In addition, there have been other smaller trials confirming that SIB treatment of pelvic lymph nodes is safe, at various fraction sizes from 1.56 Gy to 2 Gy (total doses from 50 Gy to 56 Gy) with all trials showing acute grade 3 or higher GI toxicity <3% and late grade 3 or higher GI toxicity <10% (26,(30)(31)(32)(33)(34)(35)(36).…”