Moderate Hypofractionated Radiotherapy for Lung Cancer

The purpose of this study is to evaluate the incidences of Grade III and above radiation-reduced esophagitis and radiation-reduced pneumonia of patients with advanced lung cancer treated with moderate hypofractionated (3Gy/f) radiotherapy, and their predictors. Efficacies are also evaluated.

Radiotherapy plays an irreplaceable role in lung cancer. However, due to the long duration of conventional fractionation irradiation, tumor cells will accelerate repopulation after 3 to 4 weeks during radiotherapy, resulting in decreased efficacy. Hypofractionated radiation is increasingly used in radiotherapy of lung cancer. It can shorten the overall treatment time, and can potentially reduce the effect of tumor accelerated repopulation. Compared with conventional radiotherapy, hypofractionated radiotherapy can theoretically obtain a higher biological effective dose (BED). The application of Stereotactic Body Radiation Therapy (SBRT) or Stereotactic Ablative Radiotherapy (SABR) in advanced or central lung cancer is restricted when the tumors are adjacent to important organs. Moderate hypofractionated radiotherapy can not only shorten the overall total treatment time, but also reduce the severe toxicities. It is widely used in lung cancer nowadays. However, most data of the tolerated doses for normal tissue and organs comes from conventional radiotherapy. Whether or not it is suitable for hypofractionated radiotherapy has not been determined. In our study, the incidences of Grade III and above radiation-reduced esophagitis and radiation-reduced pneumonia, as well as their predictors, were obtained by retrospective analysis of patients received moderate hypofractionated radiotherapy of 3Gy/f. At the same time, the efficacies of this scheme are also evaluated.

Hypofractionated radiotherapy;, Radiation-reduced esophagitis;, Radiation-reduced pneumonitis;Predictor

The patients received daily accelerated radiotherapy with a total dose of 60Gy, delivered at 3Gy per fraction, five fractions per week, completed within 4 weeks.

Inclusion Criteria: Patients with previously untreated advanced lung cancer were recruited, who were confirmed pathologically or cytologically. The Karnofsky performance status (KPS) score ≥60. The expected survival time was≥3 months. The laboratory examination results showed a neutrophil count ≥2.0 × 109, a hemoglobin level ≥100 g/L, a platelet count ≥100 × 109, and enough liver and kidney functions. The patients did not show abnormal electrocardiogram (ECG) results. They did not have other combined diseases that required hospitalization. Informed consent required before enrollment. Exclusion Criteria: Patients who were pregnant or breastfeeding. Patients who had another malignant tumor history (with the exception of patients with cervical carcinoma in situ and non-malignant melanoma skin cancer that had been clinically cured for at least 5 years), could not receive concurrent chemotherapy due to medical reasons. Superior vena cava syndrome. Syndrome and severe lung diseases that affected lung function were excluded.