Monitoring the Maintainability of Deep Inspiration Phase with Cine Acquisition in Patients with Left-Sided Breast Carcinoma Receiving Radiotherapy

Abstract

Objectives: This prospective study aimed to investigate whether left-sided breast carcinoma patients could maintain deep inspiration (DI) during radiotherapy in order to reduce exposed heart volume. Methods: Twenty-one patients with left breast carcinoma receiving adjuvant breast radiotherapy were included in this study. Breath hold time was monitored using the cine acquisition mode (CAM) of a linear accelerator during treatment in every fraction. Simulated kV and treatment field images were compared to determine whether the patient could achieve the same “breath holding level” (BHD). Maintenance of BHD during beam on time was referred as “maintenance of intrafraction breath holding level” (BHM), and chest wall displacement during each treatment was measured in order to verify the BHM. Furthermore, the relation between treatment time and patient compliance was studied. Results: Sixteen patients were treated according to the deep inspiration breath hold (DIBH) protocol while 5 patients, excluded due to noncompliance, received their treatment without breath control. For the patients treated with DIBH protocol, maximum heart doses without breath control and DI phases were 3044 cGy and 1347 cGy, while mean heart doses were 348 cGy and 239 cGy, respectively. Median BHD and BHM displacements were 0.2 cm (0– 0.86 cm) and 0.07 cm (0–0.31 cm), respectively. BHD differences were <0.4 cm in all but 2 patients. Treatment time did not affect patient compliance. Conclusions: DI phase was successful in reducing heart dose and 76.2% of the patients were eligible for DIBH. Treatment during moderate DI phase can be used for selected left-sided breast carcinoma patients and CAM could monitor safe execution.