Top Line: Does whole lung irradiation improve outcomes for patients with rhabdomyosarcoma lung metastases.
The Study: Whole lung irradiation (WLI) is used in several pediatric malignancies, including rhabdomyosarcoma (RMS), to reduce the risk of pulmonary progression in patients with lung metastases. Though often well tolerated, the idea of WLI can raise questions for some providers, and noncompliance with WLI on clinical trials is a known problem. The purpose of this study was to establish the benefit of WLI in patients with RMS lung metastases treated on prospective Children’s Oncology Group (COG) trials. It included data from 143 patients treated on 4 different trials between 1999 and 2013. Even though all 4 trials mandated 15 Gy in 10 fractions WLI, only 45.5% of patients actually received WLI. Clinical and prognostic variables were similar between those who did and those who didn’t receive WLI. At 5 years, the rate of event free survival was significantly higher among those who received WLI (38.3% v 25.2%), and OS trended towards an improvement with WLI (45.5% v 32.4%, p=.08). The benefit of WLI was seen across subgroups, but patients aged 10 and older had significantly higher EFS and OS with WLI. This study highlights the challenges we often face in dealing with bias (usually unfounded) against radiation, and it underscores the importance of being a vocal proponent of the benefits of radiation for our patients.
TBL: Across multiple COG trials that mandated WLI for lung metastases, less than half of patients actually received per-protocol treatment. Those who did had superior EFS and numeric improvement in OS. | Luo, J Clin Oncol 2024
The Study: Whole lung irradiation (WLI) is used in several pediatric malignancies, including rhabdomyosarcoma (RMS), to reduce the risk of pulmonary progression in patients with lung metastases. Though often well tolerated, the idea of WLI can raise questions for some providers, and noncompliance with WLI on clinical trials is a known problem. The purpose of this study was to establish the benefit of WLI in patients with RMS lung metastases treated on prospective Children’s Oncology Group (COG) trials. It included data from 143 patients treated on 4 different trials between 1999 and 2013. Even though all 4 trials mandated 15 Gy in 10 fractions WLI, only 45.5% of patients actually received WLI. Clinical and prognostic variables were similar between those who did and those who didn’t receive WLI. At 5 years, the rate of event free survival was significantly higher among those who received WLI (38.3% v 25.2%), and OS trended towards an improvement with WLI (45.5% v 32.4%, p=.08). The benefit of WLI was seen across subgroups, but patients aged 10 and older had significantly higher EFS and OS with WLI. This study highlights the challenges we often face in dealing with bias (usually unfounded) against radiation, and it underscores the importance of being a vocal proponent of the benefits of radiation for our patients.
TBL: Across multiple COG trials that mandated WLI for lung metastases, less than half of patients actually received per-protocol treatment. Those who did had superior EFS and numeric improvement in OS. | Luo, J Clin Oncol 2024