Date Published: November 30, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Valérie Fonteyne, Nicolaas Lumen, Geert Villeirs, Piet Ost, Gert De Meerleer.
Purpose. Patients with high-risk prostate cancer (PC) can be treated with high-dose intensity-modulated radiotherapy (IMRT) and long-term androgen deprivation (AD). In this paper we report on (i) late toxicity and (ii) biochemical (bRFS) and clinical relapse-free survival (cRFS) of this combined treatment. Methods. 126 patients with high-risk PC (T3-4 or PSA >20 ng/mL or Gleason 8–10) and ≥24 months of followup were treated with high-dose IMRT and AD. Late toxicity was recorded. Biochemical relapse was defined as PSA nadir +2 ng/mL. Clinical relapse was defined as local failure or metastases. Results. The incidence of late grade 3 gastrointestinal and genitourinary toxicity was 2 and 6%, respectively. Five-year bRFS and cRFS were 73% and 86% respectively. AD was a significant predictor of bRFS (P = 0.001) and cRFS (P = 0.01). Conclusion. High-dose IMRT and AD for high-risk PC offers excellent biochemical and clinical control with low toxicity.
The of PSA screening has resulted in an increased detection rate of prostate cancer (PC) with stage migration towards lower-stage prostate cancer (PC). Nevertheless, still 12% of the patients with PC will have locally advanced (T3-4 N0 M0 or Tx N1 M0) or metastatic disease at diagnosis . More aggressive therapies are indicated for these patients as they are at increased risk of PC death . External beam radiotherapy (EBRT) is one of the standard treatment options of choice for those patients. However, when conventional low-dose (<72 Gy) EBRT is applied in patients with clinical stage T3-T4 PC, local recurrence rates mount to 30% at 10 years . Improvement of local control is important as local failure is directly correlated with distant metastasis [3, 4] and survival . Extensive evidence exists that high-dose radiotherapy (dose ≥ 74 Gy) is superior to conventional dose radiotherapy (dose 64–70 Gy) [6–8]. For high-risk patients, an increase in 5-year biochemical relapse-free survival (bRFS) of 19% has been reported when increasing the dose from 70 Gy to 80 Gy . Zelefsky et al. demonstrated that the rate of positive biopsies after EBRT dropped with 30% when the dose was increased from <70.2 Gy to >81 Gy . With modern radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT), dose escalation can safely be performed . Randomized trials support the combined use of EBRT and androgen deprivation (AD) with superior disease-specific and overall survival outcomes in patients with locally advanced-stage or high-risk disease [12, 13].
Patient characteristics and planning parameters are shown in Tables 2 and 3, respectively. Significantly fewer patients received AD in prescription group 74R72 (P = 0.002). Except for follow-up time, all other parameters were equally balanced between the different prescription groups. Median followup was 48 months.
Multiple treatment options are available for patients with high-risk PC such as surgery, high-dose EBRT, and AD.
High-dose IMRT and AD for high-risk PC offers excellent biochemical and clinical control with low toxicity.