Assessment of Doses in Critical Organs of Lung Cancer Patients During the Transition to a Hypofractionation Regime

Abstract

Purpose: To evaluate the dose loads during radiation planning for critical structures of lung cancer patients during the transition from standard RT with SD = 2 Gy to a regimen with a single dose of SD = 3 Gy.

Materials and methods: The study included a group of 53 patients who received radiation therapy using the modern IMRT (intensive modulated radiation therapy) technique. The group receiving a single dose of SD = 2 Gy included 35 patients, and the group with SD = 3 Gy included 18 patients.

Results: The group with a single dose of SD = 2 Gy is characterized by a higher dose in the target volume, as well as improved planning quality parameters HI and CI. The dose loads on critical organs in the group with SD = 2 Gy (spinal cord, heart, lungs, esophagus) are slightly higher than in the group with SD = 3 Gy, however, they remain within acceptable values. The group with SD = 3 Gy demonstrates a more gentle profile of the dose load on the risk organs, which makes this regimen preferable for patients with limited somatic reserve, especially with cardiopulmonary disorders. In addition, the SD = 3 Gy regimen is used as part of an accelerated course of treatment, which reduces the overall duration of therapy.