当前位置： SCI文献检索 > Brachytherapy期刊下所有文献 > A detailed examination of the difference between planned and treated margins in 125I permanent prostate brachytherapy.

A detailed examination of the difference between planned and treated margins in 125I permanent prostate brachytherapy.

Abstract：

PURPOSE:To determine whether potential extraprostatic extension (EPE) of prostate adenocarcinoma is covered by the prescribed dose when permanent 125I implants are planned with a 5-mm treatment margin. METHODS AND MATERIALS:The postimplant dosimetry of 60 consecutive 125I prostate implants was analyzed to determine whether there was a residual 3-mm margin, adequate for treatment of potential EPE. The implants were peripherally loaded and planned with a nominal 5-mm symmetric dose margin. Extraprostatic seeds were not used at midgland, although extraprostatic seeds were placed at the base and apex. The radial distance between the edge of the prostate and the prescription isodose line (145 Gy) was measured at the left lateral, left posterolateral, posterior, right posterolateral, and right lateral positions at the base, midgland, and apex in both the preplan and postimplant dosimetry. RESULTS:The mean postimplant margin at the base (4 +/- 2 mm) was significantly less (p < 0.01) than planned (6 +/- 2 mm) by 2 mm. The planned and postimplant margins at the midgland (5 +/- 1 mm and 5 +/- 2 mm) and apex (7 +/- 2 mm and 7 +/- 3 mm) were indistinguishable (p = 0.31 and p = 0.69, respectively). At the base, 69% of the measurements were > or = 3 mm compared with 89% and 91% at the midgland and apex, respectively. Overall, 83% of the margin measurements were > or = 3 mm. The prostate postimplant V100 and D90 were 96 +/- 4% and 193 +/- 27 Gy, respectively. CONCLUSIONS:A 5-mm planning dose margin can potentially treat most EPE. However, the postimplant margin, like other dosimetric parameters, is sensitive to source placement errors and the percentage of EPE treated depends upon how well the plan is executed. Because implant quality is operator dependent, we would not recommend brachytherapy alone for patients with a high risk of EPE.

journal_name

Brachytherapy

journal_title

Brachytherapy

authors

Patel AB,Waterman FM,Dicker AP

doi

10.1016/j.brachy.2003.09.002

keywords:

subject

Has Abstract

pub_date

2003-01-01 00:00:00

pages

223-8

issue

eissn

1538-4721

issn

1873-1449

pii

S1538472103001582

journal_volume

pub_type

杂志文章

在线工具

A detailed examination of the difference between planned and treated margins in 125I permanent prostate brachytherapy.