Is modern external beam radiotherapy with androgen deprivation therapy still a viable alternative for prostate cancer in an era of robotic surgery and brachytherapy: a comparison of Australian series

Abstract

Introduction: We compare the results of modern external-beam radiotherapy (EBRT), using combined androgen deprivation and dose-escalated intensity-modulated radiotherapy with MRI-CT fusion and daily image guidance with fiducial markers (DE-IG-IMRT), with recently published Australian series of brachytherapy and surgery.

Methods: Five-year actuarial biochemical disease-free survival (bDFS), metastasis-free survival (MFS) and prostate cancer-specific survival (PCaSS) were calculated for 675 patients treated with DE-IG-IMRT and androgen deprivation therapy (ADT). Patients had intermediate-risk (IR) and high-risk (HR) disease. A search was conducted identifying Australian reports from 2005 onwards of IR and HR patients treated with surgery or brachytherapy, reporting actuarial outcomes at 3 years or later.

Results: With a median follow-up of 59 months, our 5-year bDFS was 93.3% overall: 95.5% for IR and 91.3% for HR disease. MFS was 96.9% overall (99.0% IR, 94.9% HR), and PCaSS was 98.8% overall (100% IR, 97.7% HR). Prevalence of Grade 2 genitourinary and gastrointestinal toxicity at 5 years was 1.3% and 1.6%, with 0.3% Grade 3 genitourinary toxicity and no Grade 3 gastrointestinal toxicity. Eight reports of brachytherapy and surgery were identified. The HDR brachytherapy series' median 5-year bDFS was 82.5%, MFS 90.0% and PCaSS 97.9%. One surgical series reported 5-year bDFS of 65.5% for HR patients. One LDR series reported 5-year bDFS of 85% for IR patients.

Conclusions: Modern EBRT is at least as effective as modern Australian surgical and brachytherapy techniques. All patients considering treatment for localised prostate cancer should be referred to a radiation oncologist to discuss EBRT as an equivalent option.

Keywords: brachytherapy; external beam radiotherapy; intensity-modulated radiotherapy prostate cancer; radical prostatectomy.