Re-Irradiation in Lung Disease

The loco regional relapse is frequent in the lung disease after definitive radiotherapy or multimodal treatments. Stereotactic body radiation-therapy (SBRT) is a treatment for re-irradiation in primary or secondary lung tumors after previous radical radiotherapy or SBRT. However, high-dose re-irradiation with overlapping volumes is not without risks. Potential damage may occur by injury to surrounding normal thoracic structure. Aim of this study is to evaluate the outcomes of re-irradiation in terms of Local Control (LC), Progression Free Survival (PFS) and Overall Survival (OS) and to assess the toxicities. From April 2011 to December 2016, 18 patients received a second course of radiotherapy by SBRT. Twenty-four lesions were treated. The medium volume was 22,49cc (range 2,76- 64,9cc).Seven lesions received only one fraction of radiotherapy, 3 lesions (12%) received 23 Gy and 4 lesions (17%) received 30 Gy. Seventeen lesions received multiple fractions. Seven lesions (29%) received 45 Gy in 3 fractions, 6 lesions (25%) received 48 Gy in 8 fractions and 4 lesions (17%) received 50 Gy in 5 fractions. Previous treatment included SBRT; eleven lesions were treated with one fraction of SBRT, 2 lesions (10%) with 23 Gy and 9 lesions (43%) with 30 Gy. Six lesions (28%) received multiple fraction of SBRT: 50 Gy in 5 fractions. Three lesions (14%) received a radical course of RT, 60 Gy in 20 fractions and 1 lesion (5%) received a course of adjuvant RT, 50 Gy in 25 fractions. The median interval from the first treatment and re-irradiation was 18 months (range 3-66 months). The LC was reached in 17 out of 24 lesions re-irradiated (71%), the progression free survival (PFS) was detected in 8 out of 18 patients (44%). The median interval of PFS was 9 months (range 1-42 months). The median interval of overall survival was 12 months (range 1-54 months). At last follow up there were 13 out of 18 patients (72%) alive. The median follow-up for patients alive was 12 months (range 1-39 months). Acute toxicities were: dyspnea G1 in 2 patients (11%), 1 patients (5%) had dyspnea G2, 1 patient (5%) had retrosternal pain, 1 patient (5%) had hemoptysis G1, 1 patient (5%) had sensory neuropathy G2 and neuralgia G1, 1 patient (5%) had productive cough G2 and 1 patient (5%) had dry cough G1. Late toxicities were dyspnea G1 in 1 patient (5%), dyspnea G3 in 2 patients (11%), one of this had also, asthenia, pulmonary fibrosis G2 and rib fracture. One patient (5%) had chest wall pain, 2 patients (11%) had pulmonary fibrosis G1, and one of this had also pneumothorax G2. One patient (5%) had pulmonary fibrosis G2 and pleural effusion G1. One patient (5%) had perilesional necrosis of soft tissues. Re- irradiation of primary or secondary disease in the lung is a feasible option of treatment. We obtained good results in terms of LC, PFS and OS, with acceptable toxicity. Further studies occur to identify the doses and the best fractionation, according to the volume and the localization of the lesion.