Assessing Risk of Cardiac and Pulmonary Toxicity Profiles in VMAT Compared with 3DCRT for Esophageal Cancer

Abstract

Background: According to multiple studies, when RT is administered to any thoracic cancer, pulmonary toxicities are far more common than cardiac toxicities. Both acute and chronic cardiac toxicities are possible; the latter can build over the course of a year and cause confusion between long-term cardiac morbidity and tumour growth. In order to predict the acute and long-term effects of thoracic radiation, such as esophageal carcinoma, our study compares the dosimetric parameters between VMAT and 3DCRT technique for combined lung and heart. It also evaluates and compares the risk profile and chances associated with radiation-induced cardiac and pulmonary toxicity. Study Design: Prospective longitudinal observational study. Place and Duration of Study: 21 patients from Father Muller Medical College, Mangalore for a period of 18 months from 2023 to 2025 were included in this study. Methods: Twenty-one histologically confirmed Esophageal cancer patients received final chemoradiation. The subjects were staged using TNM (AJCC Cancer Staging Manual, 8th edition). After giving informed consent, participants joined this trial. Participants received 50.4 to 54 Gy of radiation in 25 to 28 fractions of 1.8 to 2 Gy each, five times a week, using VMAT. Offline 3D conformal radiation therapy plans for the same patients were produced to evaluate dosimetry. Esophageal and gastro-oesophageal junction cancer IMRT target volumes are determined by expert consensus. All patients received Halcyon Elite Model 6 MV Linear Accelerator treatment. Results: Combined lung V20 in VMAT is 21.50 ± 6.6% and in 3DCRT is 27.75 ± 7.36%, p value is 0.001. mean lung dose was lower with VMAT (14.9 ± 2.28 Gy) compared with 3DCRT (15.78 ± 3.1 Gy) (p = 0.136). Cardiac dose was 17.51 ± 5.4 Gy, while for 3DCRT, it was 23.2 ± 6.4 Gy (p < 0.001). Also, compared to 3DCRT (42.31 ± 15.13%), heart V25 was significantly lower with VMAT (24.38 ± 11.7%), (p < 0.001). Interpretation and Conclusion: With a reduced risk of potentially fatal cardiac and pulmonary toxicity as well as long-term morbidities, VMAT is a definitive treatment for non-operable locally advanced esophageal cancer.