Estimating the Probability of Not Completing the Intended Course of Thoracic Radiotherapy for Lung Cancer

Background/Aim: In some patients with lung cancer scheduled for thoracic radiotherapy (RT), treatment is discontinued before reaching the planned dose. For optimal treatment personalization, a tool estimating whether a patient can complete radiotherapy would be helpful. Patients and Methods: Eleven pre-RT characteristics were analyzed in 170 patients receiving local RT for lung cancer. Characteristics included age, sex, tumor site, histology, tumor and nodal stage, distant metastasis, surgery, systemic treatment, pulmonary function, and smoking history. Results: Age >75 years (p=0.038), distant metastasis (p=0.009), and forced expiratory volume in 1 second <1.2 l (p=0.038) were significantly associated with discontinuation of RT. A prognostic instrument was developed in 126 patients with complete data regarding these characteristics. It included three groups (0, 1, and 2-3 points) with non-completion rates of 33.3%, 55.0% and 75.0% (p=0.004). Conclusion: This new instrument can help estimating the probability that lung cancer patients assigned to local RT cannot complete the planned course of RT.