Commissioning and clinical implementation of low dose dual-field rotational TSET

IF 2 4区医学 Q3 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Journal of Applied Clinical Medical Physics Pub Date : 2025-07-15 DOI:10.1002/acm2.70180

Broderick Ivan McCallum-Hee, Mounir Ibrahim, Godfrey Mukwada, Pejman Rowshanfarzad, Joshua Dass, Jude Dewitt, Robert Parin, Gregory Withey, Zaid Alkhatib

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引用次数: 0

Abstract

Background

Total skin electron therapy (TSET) is a specialized technique for treating cutaneous T-cell lymphomas, such as mycosis fungoides. While traditional TSET regimens prescribe 30–36 Gy, low dose TSET at 12 Gy has gained attention due to its reduced toxicity. The dual-field rotational TSET technique, utilizing a standard linac, offers a practical solution for improved dose distribution. However, limited studies exist on its commissioning and clinical implementation.

Purpose

This study aimed to commission and clinically implement a low dose dual-field rotational TSET technique. The primary objectives were to optimize beam geometry, characterize dosimetry, and ensure treatment uniformity while maintaining compliance with ACPSEM, EORTC, and AAPM guidance.

Methods

A Varian TrueBeam linac equipped with a 6 MeV high-dose-rate total skin electron beam was commissioned for TSET. Dosimetric measurements included beam output calibration, relative dosimetry, and dose uniformity assessment using an ion chamber and Gafchromic film, with verification using an anthropomorphic phantom. A treatment dose calculation methodology was developed. Shielding, ozone generation, and quality assurance were assessed. In vivo dosimetry was performed for treatment validation.

Results

The optimal dual-field beam geometry was determined to be ± 18° from the horizontal, achieving vertical uniformity within ± 2.9% and an overall treatment plane uniformity of ± 8.6%. Under rotation, the depth dose is delivered 100% at the surface, with bremsstrahlung contamination of 0.2 Gy. Custom eye shielding was developed, and ozone concentrations remained below the NCRP 0.1 parts per million (ppm) safety thresholds. In vivo dosimetry confirmed treatment uniformity within EORTC guidelines and identified three regions requiring dose boosts: the shoulders, palms, and inner thighs.

Conclusions

The commissioned dual-field rotational TSET technique provides a viable treatment option, achieving clinically acceptable dose distribution.

Abstract Image

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低剂量双场旋转TSET的调试与临床实施

背景：全皮肤电子治疗（TSET）是一种治疗皮肤t细胞淋巴瘤的专门技术，如蕈样真菌病。虽然传统的TSET方案规定30-36 Gy，但12 Gy的低剂量TSET因其毒性降低而受到关注。双场旋转TSET技术，利用标准直线加速器，为改善剂量分布提供了实用的解决方案。然而，关于其调试和临床应用的研究有限。目的研究低剂量双视场旋转TSET技术的临床应用。主要目的是优化光束几何形状，表征剂量学，并确保治疗均匀性，同时保持ACPSEM， EORTC和AAPM指导的依从性。方法采用瓦里安TrueBeam直线加速器，配备6mev高剂量率全皮肤电子束进行TSET试验。剂量测量包括光束输出校准、相对剂量测量和使用离子室和变色膜的剂量均匀性评估，并使用拟人化幻影进行验证。提出了一种治疗剂量计算方法。对屏蔽、臭氧生成和质量保证进行了评估。进行体内剂量测定以验证治疗效果。结果最佳双场光束几何形状为水平方向±18°，垂直均匀度在±2.9%以内，整体治疗平面均匀度为±8.6%。旋转时，深度剂量100%在表面释放，轫致辐射污染为0.2 Gy。定制的眼罩被开发出来，臭氧浓度保持在NCRP规定的百万分之0.1的安全阈值以下。体内剂量测定证实了EORTC指南中治疗的一致性，并确定了三个需要增加剂量的区域：肩膀、手掌和大腿内侧。结论双场旋转TSET技术是一种可行的治疗方案，可实现临床可接受的剂量分布。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Applied Clinical Medical Physics 医学-核医学

CiteScore

3.60

自引率

19.00%

发文量

331

审稿时长

3 months

期刊介绍： Journal of Applied Clinical Medical Physics is an international Open Access publication dedicated to clinical medical physics. JACMP welcomes original contributions dealing with all aspects of medical physics from scientists working in the clinical medical physics around the world. JACMP accepts only online submission. JACMP will publish: -Original Contributions: Peer-reviewed, investigations that represent new and significant contributions to the field. Recommended word count: up to 7500. -Review Articles: Reviews of major areas or sub-areas in the field of clinical medical physics. These articles may be of any length and are peer reviewed. -Technical Notes: These should be no longer than 3000 words, including key references. -Letters to the Editor: Comments on papers published in JACMP or on any other matters of interest to clinical medical physics. These should not be more than 1250 (including the literature) and their publication is only based on the decision of the editor, who occasionally asks experts on the merit of the contents. -Book Reviews: The editorial office solicits Book Reviews. -Announcements of Forthcoming Meetings: The Editor may provide notice of forthcoming meetings, course offerings, and other events relevant to clinical medical physics. -Parallel Opposed Editorial: We welcome topics relevant to clinical practice and medical physics profession. The contents can be controversial debate or opposed aspects of an issue. One author argues for the position and the other against. Each side of the debate contains an opening statement up to 800 words, followed by a rebuttal up to 500 words. Readers interested in participating in this series should contact the moderator with a proposed title and a short description of the topic