HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: 2213010130v1 221/3/623    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Beyer, D. C. Articles by Gurgoze, E. M. Search for Related Content PubMed PubMed Citation Articles by Beyer, D. C. Articles by Gurgoze, E. M.

Prostate Brachytherapy: Comparison of Dose Distribution with Different ¹²⁵I Source Designs¹

¹ From Arizona Oncology Services, 8994 E Desert Cove Ave, Suite 100, Scottsdale, AZ 85260. From the 2000 RSNA scientific assembly. Received December 13, 2000; revision requested February 3, 2001; revision received April 9; accepted May 1. Address correspondence to D.C.B. (e-mail: dbeyer@azoncology.com).

PURPOSE: To evaluate the interchangeability of various commercially available iodine 125 (¹²⁵I) sources and to assess the dosimetric effect of a change in source.

MATERIALS AND METHODS: A modified peripherally loading prostate brachytherapy plan to deliver 145 Gy was devised by using a model ¹²⁵I source, which until recently was the only available ¹²⁵I source. A dose-volume histogram was generated. By using the available radial dose functions and anisotropy distributions for eight other currently commercially available sources, the same implant placement was planned and dose-volume histogram distributions tabulated. This exercise was performed for 15-, 45-, and 60-cm³ glands. No implants were placed, and no physical radiation measurements were made. Dose calculations were theoretic: They were generated by using a widely available treatment planning system.

RESULTS: There was little difference in dose distribution to the volume receiving 100% of the prescribed dose (<6%); only one source showed a difference greater than 2%. Large differences, up to -40% to +60%, were seen in the volume of tissue encompassed within internal high-dose regions receiving 150% or 200% of the prescribed dose. These findings held true, irrespective of gland size, within a clinically relevant range (15–60 cm³) and for a uniformly loaded radionuclide distribution.

CONCLUSION: Reviewing only peripheral dose at or near the prescription dose of 145 Gy revealed little difference in doses for various source designs. Marked differences in high-dose regions were seen and may affect the dose received by internal sites. Effects of these changes on cure and/or complications remain speculative.

Index terms: Prostate neoplasms, therapeutic radiology, 844.12168, 844.1299, 844.452 • Radiations, exposure to patients and personnel, 844.452