Rectal morbidity after permanent interstitial brachytherapy for prostate cancer—Impact of Day 1 vs. Day 30 computed tomography–based postimplant dosimetry

Pinkawa, Michael; Piroth, Marc D.; Holy, Richard; Klotz, Jens; Nussen, Sandra; Borchers, Holger; Heidenreich, Axel; Eble, Michael J.

doi:10.1016/j.brachy.2009.04.003

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Volume 9, Issue 1 , Pages 1-7, January 2010

Rectal morbidity after permanent interstitial brachytherapy for prostate cancer—Impact of Day 1 vs. Day 30 computed tomography–based postimplant dosimetry

Michael Pinkawa
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
- Corresponding author. Department of Radiation Oncology, RWTH Aachen University, Pauwelsstrasse 30, 52057 Aachen, Germany. Tel.: +49-241-80-35314; fax: +49-241-80-82543.
Marc D. Piroth
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Richard Holy
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Jens Klotz
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Sandra Nussen
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Holger Borchers
- Department of Urology, RWTH Aachen University, Aachen, Germany
Axel Heidenreich
- Department of Urology, RWTH Aachen University, Aachen, Germany
Michael J. Eble
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany

Received 16 March 2009; received in revised form 24 April 2009; accepted 28 April 2009. published online 04 September 2009.

Abstract

Purpose

The aim of the study was to evaluate bowel quality-of-life changes after prostate brachytherapy and the impact of Day 1 vs. Day 30 postimplant dosimetry.

Methods and Materials

In 61 patients, computed tomography (CT) scans were performed at Days 1 and 30 after ¹²⁵I brachytherapy. The patients have been surveyed prospectively before (time A), 1 month (time B), and >1 year after treatment (time C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Different parameters were tested for their predictive value on bowel quality-of-life changes (bowel bother score decrease >20 points at time B=BB20; bowel bother score decrease >10 points at time C=BC10), including seed displacements.

Results

Mean bowel function/bother score decreased 13/13 points at time B (p<0.01) and 1/4 points at time C (change not significant). BB20 and BC10 were found in 25% and 20% of patients, respectively. Bowel bother score declines at time B correlated well with declines at time C (r=0.53; p<0.01). Prostate volume before implantation and the number of seeds per cubic centimeters were found to be predictive for BB20 and BC10. Smaller rectal wall volumes covered by the 60–100% isodoses at Day 1 were (paradoxically) found to be significantly predictive for BC10. Larger posterior seed displacements between Days 1 and 30 were significantly associated with BB20.

Conclusions

Quality-of-life scores have not been found to change significantly >1 year after brachytherapy. Larger rectal wall volumes within higher isodoses at Day 1 or 30 were not found to be predisposing for adverse quality-of-life changes.

Keywords: Prostate neoplasm, Brachytherapy, ¹²⁵I, Postimplant dosimetry, Quality of life