Long-term outcomes from dose-escalated image-guided intensity-modulated radiotherapy with androgen deprivation: encouraging results for intermediate- and high-risk prostate cancer

Abstract

PurposeDose-escalated (DE) radiotherapy in the setting of localized prostate cancer has been shown to improve biochemical disease-free survival (bDFS) in several studies. In the same group of patients, androgen deprivation therapy (ADT) has been shown to confer a survival benefit when combined with radiotherapy doses of up to 70 Gy; however, there is currently little long-term data on patients who have received high-dose intensity-modulated radiotherapy (IMRT) with ADT. We report the long-term outcomes in a large cohort of patients treated with the combination of DE image-guided IMRT (IG-IMRT) and ADT.Methods and materialsPatients with localized prostate cancer were identified from a centralized database across an integrated cancer center. All patients received DE IG-IMRT, combined with ADT, and had a minimum follow up of 12 months post-radiotherapy. All relapse and toxicity data were collected prospectively. Actuarial bDFS, metastasis-free survival, prostate cancer-specific survival, and multivariate analyses were calculated using the SPSS v20.0 statistical package.ResultsSeven hundred and eighty-two eligible patients were identified with a median follow up of 46 months. Overall, 4.3% of patients relapsed, 2.0% developed distant metastases, and 0.6% died from metastatic prostate cancer. At 5-years, bDFS was 88%, metastasis-free survival was 95%, and prostate cancer-specific survival was 98%. Five-year grade 2 genitourinary and gastrointestinal toxicity was 2.1% and 3.4%, respectively. No grade 3 or 4 late toxicities were reported. Pretreatment prostate specific antigen (P=0.001) and Gleason score (P=0.03) were significant in predicting biochemical failure on multivariate analysis.ConclusionThere is a high probability of tumor control with DE IG-IMRT combined with androgen deprivation, and this is a technique with a low probability of significant late toxicity. Our long term results corroborate the safety and efficacy of treating with IG-IMRT to high doses and compares favorably with published series for the treatment of prostate cancer.

Definitive intensity‐modulated radiotherapy concurrent with systemic therapy for oropharyngeal squamous cell carcinoma: Outcomes from an integrated regional Australian cancer centre

“…Finally, our experience and results demonstrate that ‘Not all rural and regional centres are low‐volume centres’. The NCCI has previously published IMRT outcomes for other cancer sites, which support our notion that providing IMRT in rural or regional centres can produce comparable outcomes as large tertiary centres …”

Can a peri‐rectal hydrogel spaceOAR programme for prostate cancer intensity‐modulated radiotherapy be successfully implemented in a regional setting?

“…Of interest in our study was that there was no significant benefit seen for SpaceOAR patients in terms of proctitis or faecal incontinence. However, the baseline rates of these toxicities in our patients is very low (as previously reported), and it is possible larger numbers of patients would be required to determine any differences. In addition, we do not report long‐term late toxicity which may better demonstrate any potential benefits of SpaceOAR rectal dose reductions.…”

Prostate intensity-modulated radiotherapy planning in seven mouse clicks: Development of a class solution for cancer

“…This final stage of the class solution demonstrated that 89% of prostate patients met treatment criteria outright (S. Greenham, personal communication). Further research is required to determine whether prostate class solutions can maintain or improve upon the clinical and patient-reported outcomes 5,6,15 of dose-escalated image-guided IMRT.…”

“…These patients were volumed using magnetic resonance imaging (MRI) and computed tomography (CT) fusion 4 and treated to 81 Gy as previously described. 5,6 Planning criteria and OAR constraints are summarised in Tables 1 and 2 and were based on evidencebased guidelines (EviQ recommendations). 7 Minor violations were acceptable when all reasonable efforts to achieve ideal constraints had been made.…”