Early Tolerance Outcomes of Stereotactic Hypofractionated Accelerated Radiation Therapy Concomitant with Pelvic Node Irradiation in High-risk Prostate Cancer

Abstract

Purpose This study aimed to evaluate the toxicity of prostate and pelvic lymph node stereotactic body radiation therapy (SBRT) for high-risk prostate cancer. Methods and Materials Twenty-three patients with high-risk or lymph node-positive prostate cancer were treated with SBRT that delivered 37.5 to 40 Gy in 5 fractions to the prostate and seminal vesicles, with concomitant treatment of the pelvic nodes to 25 Gy. In general, patients received neoadjuvant, concurrent, and adjuvant androgen deprivation therapy for a duration of 18 months. Toxicities were evaluated with the Common Terminology Criteria for Adverse Events, version 3.0. The median follow-up was 19 months (range, 3-48 months). Results Acute grade 1 gastrointestinal (GI) toxicities were noted in 2 patients (9.1%). No patient experienced acute grade ≥2 GI toxicity. Acute genitourinary (GU) grade 1, 2, and 3 toxicities were observed in 7 patients (31.8%), 8 patients (36.4%), and 1 patient (4.5%), respectively. Late grade 2 GI and GU toxicities were observed in 2 patients (9.1%) and 6 patients (27.3%), respectively. No late grade ≥3 GI toxicity was noted. Late grade ≥3 GU (hemorrhagic cystitis) was noted in 1 patient (4.5%), which responded to laser fulguration. Conclusions SBRT with pelvic lymph node radiation therapy was feasible and well tolerated. The incidence of grade ≥3 GU and GI toxicities was uncommon. Continued follow-up will be required to determine the long-term safety and efficacy of this approach for high-risk patients.

A Prospective Study of Stereotactic Body Radiotherapy (SBRT) with Concomitant Whole-Pelvic Radiotherapy (WPRT) for High-Risk Localized Prostate Cancer Patients Using 1.5 Tesla Magnetic Resonance Guidance: The Preliminary Clinical Outcome

“…With a low α/β value of PC cells, hypofractionated RT or ultra-hypofractionation may result in more substantial radiobiological responsiveness, and the clinical outcome in PC patients may be further enhanced as a consequence [ 51 , 52 , 53 ]. With the potential radiobiological advantage, as well as the promising outcome with ultra-hypofractionated RT for LR- and IR-PC, SBRT has been actively investigated for HR-PC with or without ADT in recent years [ 24 , 27 , 28 , 29 , 30 , 38 , 39 , 40 , 54 , 55 , 56 ]. In the meantime, conventionally fractionated WPRT in addition to prostate-alone RT has been shown to improve the clinical outcome for HR-PC in the POP-RT study.…”

“…In the meantime, conventionally fractionated WPRT in addition to prostate-alone RT has been shown to improve the clinical outcome for HR-PC in the POP-RT study. Nonetheless, among those SBRT studies in HR-PC patients, concomitant WPRT and prostate SBRT were evaluated in only a few of them [ 27 , 38 , 39 , 40 , 56 ].…”

“…As in the subset of LR- or IR-PC, SBRT might potentially lead to similar or improved oncological outcomes to conventionally fractionated RT. Few studies [ 27 , 38 , 39 , 40 ] have been conducted to explore the feasibility and safety of this novel approach. Most of these studies [ 27 , 38 , 39 ] preliminarily showed good early tolerance and low toxicity except for the phase I FASTR study [ 40 ].…”

“…Few studies [ 27 , 38 , 39 , 40 ] have been conducted to explore the feasibility and safety of this novel approach. Most of these studies [ 27 , 38 , 39 ] preliminarily showed good early tolerance and low toxicity except for the phase I FASTR study [ 40 ]. Higher-than-anticipated late toxicities were observed in the phase I FASTR study, and it was terminated before the phase 2 accrual.…”

Safety and Efficacy of Ultra-hypofractionation in Node-positive Prostate Cancer

“…There were no grade 3 gastrointestinal toxicities and only one patient (4.5%) had grade 3 genitourinary toxicity. They attributed lower toxicities to the use of tight PTV margins and MRI-based contouring and planning [28].…”