Varied Head Position in Supraclavicular Nodal Irradiation using IMRT Technique and its Effect on Dysphagia in Breast Cancer Patients

Abstract

Introduction: Locally advanced breast cancer patients undergo a tri-modality therapy in which radiotherapy has a significant role. Toxicities associated with adjuvant radiotherapy are reduced to a minimum with the advancement of techniques, but the acute toxicities that occur during supraclavicular field radiation, like pharyngitis and esophagitis, need to be addressed. To reduce the severity of the dysphagia, variation in head position during radiation is also a commonly used and scarcely studied method. The purpose of the study is to compare the dose received by the Pharyngo-Esophageal Segment in the head-straight and head-turn positions and its correlation with dysphagia.

Methods: One hundred patients were randomized into head-straight or head-turn positions during immobilization. After the simulation scan, the targets and organs at risk were contoured in both groups according to the guidelines, and additionally, the Pharyngo-Esophageal Segment was contoured. Both groups received the same radiation dose to the supraclavicular field using the intensity modulated radiotherapy technique and were assessed for dysphagia.

Result: Fifty-three right-sided and 47 left-sided breast cancers were accrued with their age ranging from 30 to 82 years. The average Pharyngo-Esophageal Segment length, of mean dose, maximum dose, and dose of 2cc volume in head straight position group were 4.5 cm, 24 Gy, 40.4 Gy, and 25.9 Gy, respectively; whereas in head turn group the values were 5.5 cm, 30.3 Gy, 41.2 Gy, and 34.4 Gy, respectively. These parameters were significantly lower in the head straight position than head turn position, with the p-value being p=0.005, p<0.001, p=0.04, p<0.001, respectively.

Conclusion: The head straight immobilization can be considered during supraclavicular irradiation, as it significantly reduces dose to the Pharyngo-Esophageal Segment.