Cancer Management and Research (Dec 2022)
A Dosimetric Study Comparing Different Radiotherapy Planning Techniques With and Without Deep Inspiratory Breath Hold for Breast Cancer
Abstract
Sarath S Nair,1,2 V N Meena Devi,1 Krishna Sharan,2 Jyothi Nagesh,2 Brahmaiah Nallapati,2 Shambhavi Kotian3 1Department of Physics, Noorul Islam Centre for Higher Education Kumaracoil, Tamilnadu, India; 2Department of Radiotherapy & Oncology, Kasturba Medical College Manipal, Manipal Academy of Higher Education, Manipal, India; 3Department of Medical Physics, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, IndiaCorrespondence: Sarath S Nair, Email [email protected]: To analyze whether deep inspiratory breath hold (DIBH) would be dosimetrically beneficial irrespective of radiotherapy planning techniques for patients with left breast cancers requiring adjuvant radiotherapy.Methods: Planning CT scans were taken in free-breathing (FB) as well as deep-inspiration breath hold (DIBH) for patients requiring adjuvant radiotherapy for left breast cancers. After registration, three radiotherapy plans – 3D-conformal radiotherapy (3DCRT), intensity modulated RT (IMRT), and volumetric modulated arc-therapy (VMAT) – were generated for both FB and DIBH scans for each patient. The dose-volume parameters were collected from the dose-volume histogram and analyzed. A paired t-test is used for statistical analysis of the parameters.Findings: The study was conducted on thirteen patients. The mean dose of the left lung was reduced with DIBH by 32%, 24%, and 6% (8.6 Gy, 6.6 Gy, and 6.4 Gy) with 3DCRT, IMRT, and VMAT, respectively. The mean heart dose was reduced by 3.3 Gy (2.2 vs 5.5 Gy), 2.2 Gy (7.5 vs 9.7 Gy), and 1.2 Gy (5.8 vs 7 Gy) with 3DCRT, IMRT, and VMAT with DIBH. Similarly, the left anterior descending artery (LAD) mean dose was relatively reduced by 80%, 34%, and 20% when compared with the FB scans for 3DCRT, IMRT, and VMAT respectively, with max dose in the 3DCRT plan.Novelty/Applications: DIBH appears to have maximum benefit in achieving a better sparing of organs-at-risk for patients being considered for 3DCRT, and to a lesser extent with even IMRT and VMAT techniques.Keywords: deep inspiration breath hold, DIBH, active breath coordinator, ABC, volumetric modulated arc therapy, VMAT, intensity modulated radiation therapy, IMRT, left anterior descending coronary artery, LAD
