Toxicity and early treatment outcomes in low- and intermediate-risk prostate cancer managed by high-dose-rate brachytherapy as a monotherapy

Ghadjar, Pirus; Keller, Tamara; Rentsch, Cyrill A.; Isaak, Bernhard; Behrensmeier, Frank; Stroux, Andrea; Thalmann, George N.; Aebersold, Daniel M.

doi:10.1016/j.brachy.2008.09.004

« Previous Next »Brachytherapy
Volume 8, Issue 1 , Pages 45-51, January 2009

Toxicity and early treatment outcomes in low- and intermediate-risk prostate cancer managed by high-dose-rate brachytherapy as a monotherapy

Pirus Ghadjar
- Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland
Tamara Keller
- Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland
Cyrill A. Rentsch
- Department of Urology, University of Bern, Inselspital, Bern, Switzerland
Bernhard Isaak
- Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland
Frank Behrensmeier
- Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland
Andrea Stroux
- Charité University Medicine Berlin, Institute for Biometry and Clinical Epidemiology, Berlin, Germany
George N. Thalmann
- Department of Urology, University of Bern, Inselspital, Bern, Switzerland
Daniel M. Aebersold
- Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland
- Corresponding author. Department of Radiation Oncology, University of Bern, Inselspital, Freiburgstrasse, 3011 Bern, Switzerland. Tel.: +41-31-632-2431; fax: +41-31-382-2342.

Received 11 June 2008; received in revised form 24 September 2008; accepted 26 September 2008. published online 27 November 2008.

Abstract

Purpose

To determine the acute and late genitourinary (GU) and gastrointestinal (GI) toxicity and present short-term biochemical no evidence of disease (bNED) rates after high-dose-rate brachytherapy (HDR-B) monotherapy.

Methods and Materials

Between October 2003 and June 2006, 36 patients with low (28) and intermediate (8) risk prostate cancer (PCA) were treated by HDR-B monotherapy. All patients received one implant and four fractions of 9.5Gy within 48h for a total prescribed dose (PD) of 38Gy. Five patients received hormonal therapy (HT). Median age was 63.5 years and median followup was 3 years (range, 0.4–4 years). Toxicity was scored according to the CTCAE version 3.0. Biochemical failure was defined according to the Phoenix criteria.

Results

Acute and late Grade 3 GU toxicity was observed in 1 (3%) and 4 (11%) patients, respectively. Grade 3 GI toxicity was absent. The three- year bNED survival rate was 100%. The sexual preservation rate in patients without HT was 75%. Late Grade 3 GU toxicity was associated with the planning target volume (PTV) V₁₀₀ (% PTV receiving ≥100% of the PD; p=0.036), D₉₀ (dose delivered to 90% of the PTV; p=0.02), and the urethral V₁₂₀ (urethral volume receiving ≥120% of the PD; p=0.043). The urethral V₁₂₀ was associated with increased PTV V₁₀₀ (p<0.001) and D₉₀ (p=0.003).

Conclusions

After HDR-B monotherapy, late Grade 3 GU toxicity is associated with the urethral V₁₂₀ and the V₁₀₀ and D₉₀ of the PTV. Decrease of the irradiated urethral volume may reduce the GU toxicity and potentially improve the therapeutic ratio of this treatment.

Keywords: HDR-brachytherapy, Monotherapy, Prostate cancer, Urethral dose