Effect of hypofractionated radiotherapy on lung functions in breast cancer patients

Background Adjuvant hypofractionated radiotherapy (RT) used in the management of breast cancer cases, although reduce time and cost, may have serious effects due to the increased dose of radiation. Radiation-induced lung injury is an important side effect of thoracic radiation. Aim In our study, patients assessed by spirometry to detect acute changes in lung functions resulted from radiation exposure during the treatment of breast cancer. Patients and methods In this prospective study, 31 patients with breast cancer, who received adjuvant RT in Ain Shams University Hospitals, were assessed by spirometry before and 8 weeks after the end of RT. Radiation pneumonitis (RP) was graded using the Common Terminology Criteria for Adverse Events, version 5. Pulmonary function was evaluated by spirometry before and 8 weeks after finishing RT to detect changes in forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC ratio, forced expiratory flow at 25–75% of FVC (FEF25%–75%), and FEF50% of . Results Five (16.1%) patients developed symptomatic RP. Significant reduction was noticed in FVC and FEV1, while FEV1/FVC ratio, FEF25%–75%, and FEF50% were not significantly affected. It was also observed that FEV1 was sensitive in anticipating RP. Conclusion Spirometry parameters, FEV1 and FVC, significantly decreased after 8 weeks of RT ending, without significant decrease in other parameters, favoring restrictive lung injury pattern. Since most cancer breast patients who developed RP were asymptomatic, spirometry was found to be beneficial in identifying patients with risk of radiation-induced lung injury (RP).