ABSTRACT
PURPOSE: To analyze toxicity and outcome predictors in Ewing sarcoma patients with lung metastases treated with busulfan and melphalan (BU-MEL) followed by whole-lung irradiation (WLI). METHODS: This retrospective study included 68 lung metastatic Ewing Sarcoma patients who underwent WLI after BU-MEL with autologous stem cell transplantation, as part of two prospective and consecutive treatment protocols. WLI 12 Gy for <14 years old and 15 Gy for ≥14 years old patients were applied at least eight weeks after BU-MEL. Toxicity, overall survival (OS), event-free survival (EFS) and pulmonary relapse-free survival (PRFS) were estimated and analyzed. RESULTS: After WLI, grade 1-2 and grade 3 clinical toxicity was reported in 16.2% and 5.9% patients, respectively. The five-year OS, EFS and PRFS with 95% confidence interval (CI) were 69.8% (57.1-79.3), 61.2% (48.4-71.7) and 70.5% (56.3-80.8), respectively. Patients with good histological necrosis of the primary tumor after neoadjuvant chemotherapy showed a significant decreased risk of pulmonary relapse or death compared to patients with poor histological necrosis. CONCLUSIONS: WLI at recommended doses and time interval after BU-MEL is feasible and might contribute to the disease control in Ewing sarcoma with lung metastases and responsive disease. Further studies are needed to explore the treatment stratification based on the histological response of the primary tumor.
ABSTRACT
BACKGROUND/AIM: Whole lung irradiation (WLI) represents standard therapy for patients with pulmonary metastases from Ewing sarcoma although the impact on clinical outcomes and toxicity is still unclear. The aim of this study was to evaluate toxicity after WLI in patients with Ewing sarcoma and osteosarcoma as well as overall survival (OS) and event-free survival (EFS). MATERIALS AND METHODS: A systematic review of studies on bilateral pulmonary irradiation treatments for prophylactic or curative therapy was performed based on PRISMA methodology. Data base searches on PubMed and Cochrane Library from the earliest time possible through 31st March 2018 were carried out. Combination with other treatments, such as chemotherapy and surgery were allowed. Only articles published in English were considered. RESULTS: Toxicity was evaluated in 13 of the 14 analyzed studies (640 patients). Reported lung acute toxicity grade ≥3 ranged between 0.0 and 12.2%. Three studies reported 12 cases (1.8%) of severe pneumonitis. Grade ≥2 late toxicity was mainly recorded in patients who received boost irradiation, previous thoracic surgery, chemotherapy or who were smokers. Lack of a significant impact of WLI on OS was reported in comparative studies although patients treated with WLI showed higher survival in most individual studies. CONCLUSION: Although the rate of severe toxicity was very low, the real impact of WLI on patients' outcomes remains unproven, probably due to the narrow dose limits that can be delivered to the whole lung parenchyma. New strategies to prevent or treat lung metastases in these patients should be tested. Ultra-fractionated radiotherapy concurrent with modern chemotherapy protocols could be tested in this setting due to the chemo-sensitizing effect and negligible radio-induced toxicity of fraction doses <0.5 Gy.
