A dosimetric and centeredness comparison of the conventional and novel endobronchial applicators: A preliminary study.

Abstract

PURPOSE:

This study compared the applicator position relative to the tracheal wall and dosimetric parameters between conventional and novel applicators among patients receiving endobronchial brachytherapy (EBBT) for intratracheal tumors.

METHODS AND MATERIALS:

Data from 7 patients who received EBBT for intratracheal tumors were retrospectively analyzed; 4 and 3 patients were treated with conventional (2-wing) or novel (5-wing) applicators, respectively. Applicator centrality was evaluated using the distance between the center of the trachea and main bronchus (TMB) lumen and path of source (L). Dosimetric parameters, including plans normalized to D2cc of the TMB = 45 Gy (normalized plan), were compared between the applicators.

RESULTS:

The mean and maximum values of L in cases of the 2-wing applicator group were approximately 5.0 mm and 10.0 mm, respectively. In the novel applicator group, the corresponding values were approximately 3.0 and 6.0 mm, respectively. In the normalized plan of the 2-wing applicator group, the ranges of median V90% of clinical target volume (CTV) and D0.1cc of the TMB in all cases were 23.0-91.9% and 66.3-153.1 Gy, respectively. In the 5-wing applicator group, the corresponding values were 69.2-83.8% and 60.4-84.5 Gy, respectively.

CONCLUSIONS:

In the 5-wing applicator group, the range was narrow in all dose-volume parameters except for D2cc of the TMB. Compared to the conventional applicator, the 5-wing applicator can give a stable dose to the CTV and can reduce the maximum dose of the TMB. This suggests that stable EBBT can be given to any patient using the 5-wing applicator.

• Authors: Kotaro Iijima, Naoya Murakami, Hiroyuki Okamoto, Satoshi Nakamura, Shie Nishioka, Takahito Chiba, Junichi Kuwahara, Hiroki Nakayama, Mihiro Takemori, Ako Aikawa, Shibata Yoshihiro, Tairo Kashihara, Kana Takahashi, Koji Inaba, Kae Okuma, Hiroshi Igaki, Yuko Nakayama, Jun Itami
• Journal: Brachytherapy (Brachytherapy) 2021 Mar-Apr Vol. 20 Issue 2 Pg. 467-477 ISSN: 1873-1449 [Electronic] United States
• PMID: 33353847 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Topics

• Brachytherapy (methods)
• Humans
• Radiometry
• Radiotherapy Dosage
• Radiotherapy Planning, Computer-Assisted
• Retrospective Studies