Nangia Sapna, Burela Nagarjuna, Sawant Mayur, Aishwarya G, Joshua Patrick, Thiyagarajan Vijay, Gaikwad Utpal, Sharma Dayananda S
Dept of Radiation Oncology, Apollo Proton Cancer Centre, Chennai, Tamil Nadu, India.
Clinical Physics, Accuray Medical Equipment Pvt Ltd, India.
Tech Innov Patient Support Radiat Oncol. 2024 Mar 17;30:100244. doi: 10.1016/j.tipsro.2024.100244. eCollection 2024 Jun.
The clinical implementation of deep inspiratory breath-hold (DIBH) radiotherapy to reduce cardiac exposure in patients with left-sided breast cancer is challenging with helical tomotherapy(HT) and has received little attention. We describe our novel approach to DIBH irradiation in HT using a specially designed frame and manual gating, and compare cardiac substructure doses with the free-breathing (FB) technique.
The workflow incorporates staggered junctions and a frame that provides tactile feedback to the patient and monitoring for manual cut-off. The treatment parameters and clinical outcome of 20 patients with left-sided breast cancer who have undergone DIBH radiotherapy as a part of an ongoing prospective registry are reported. All patients underwent CT scans in Free Breathing (FB) and DIBH using the in-house Respiframe, which incorporates a tactile feedback-based system with an indicator pencil. Plans compared target coverage, cardiac doses, synchronizing treatment with breath-hold and avoiding junction repetition. MVCT scans are used for patient alignment.
The mean dose (Dmean) to the heart was reduced by an average of 34 % in DIBH-HT compared to FB-HT plans (3.8 Gy vs 5.7 Gy). Similarly, 32 % and 67.8 % dose reduction were noted in the maximum dose (D0.02 cc) of the left anterior descending artery, mean 12.3 Gy vs 18.1 Gy, and mean left ventricle V5Gy 13.2 % vs 41.1 %, respectively. The mean treatment duration was 451.5 sec with a median 8 breath-holds; 3 % junction locations between successive breath-holds were replicated. No locoregional or distant recurrences were observed in the 9-month median follow-up.
Our workflow for DIBH with Helical-Tomotherapy addresses patient safety, treatment precision and challenges specific to this treatment unit. The workflow prevents junction issues by varying daily breath-hold durations and avoiding junction locations, providing a practical solution for left-sided breast cancer treatment with HT.
在左侧乳腺癌患者中，采用深吸气屏气（DIBH）放疗以减少心脏受照剂量，对于螺旋断层放疗（HT）来说具有挑战性，且很少受到关注。我们描述了一种在HT中使用特殊设计的框架和手动门控进行DIBH照射的新方法，并将心脏亚结构剂量与自由呼吸（FB）技术进行比较。
该工作流程采用交错连接和一个能为患者提供触觉反馈并监测手动切断的框架。报告了20例接受DIBH放疗的左侧乳腺癌患者的治疗参数和临床结果，这些患者是正在进行的前瞻性登记研究的一部分。所有患者使用内部的呼吸框架在自由呼吸（FB）和DIBH状态下进行CT扫描，该框架包含一个基于触觉反馈的系统和一支指示笔。计划比较了靶区覆盖情况、心脏剂量、屏气同步治疗以及避免连接重复。MVCT扫描用于患者定位。
与FB-HT计划相比，DIBH-HT中平均心脏剂量（Dmean）平均降低了34%（3.8 Gy对5.7 Gy）。同样，左前降支动脉的最大剂量（D0.02 cc）分别降低了32%和67.8%，平均为12.3 Gy对18.1 Gy，左心室平均V5Gy分别为13.2%对41.1%。平均治疗持续时间为451.5秒，平均屏气8次；连续屏气之间3%的连接位置重复。在9个月的中位随访期内未观察到局部或远处复发。
我们的螺旋断层放疗DIBH工作流程解决了患者安全、治疗精度以及该治疗设备特有的挑战。该工作流程通过改变每日屏气持续时间和避免连接位置来防止连接问题，为HT治疗左侧乳腺癌提供了一种实用的解决方案。
