Retrospective analysis of toxicities and clinical efficacy of postoperative radiotherapy for pediatric nephroblastoma / 中华放射肿瘤学杂志

ABSTRACT

Objective:To evaluate the toxicities and clinical efficacy of postoperative radiotherapy for children with nephroblastoma (Wilms’ tumor).Methods:In total, 116 WT Children (≤14-year-old) treated with radiotherapy (RT) in our center from 2005 to 2018 were recruited in this retrospective analysis. RT-induced toxicities and clinical efficacy were analyzed. RT was performed guided by Children′s Oncology Group (COG) protocol. The overall survival (OS), flank-field control (LC), abdominal control (AC), and distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method. pathologically proved.Results:From January, 2005 to August, 2018, 116 pathologically proved WT patients were enrolled. Most of them were diagnosed with favorable WT (94.8%) and stage Ⅲ WT (87.1%). With a median follow-up time of 30.4(0.7-185.7) months, the 3-year OS, LC, AC and DMFS were 83.9%, 78.2%, 75.2% and 82.8%, respectively. Sixty-four (55.2%) patients suffered from Grade I to Ⅱ gastrointestinal toxicities and Grade I to IV hematological toxicities. Only 5 patients (4.3%) had Grade Ⅱ late toxicities. For 96 patients who received adjuvant RT, the median surgery-RT interval time was 1.2(0.5 to 7.1) months. The 3-year OS, LC, AC and DMFS were 88.1%, 96.7%, 92.7% and 86.9%, respectively. Patients with tumor rupture without whole abdomen irradiation (WAI) tended to have lower AC, DMFS and OS. Twenty children received salvage RT when they had disease relapse. The 3-year OS and DMFS of patients with salvage RT were significantly worse than those receiving adjuvant RT (OS 68.2% vs. 88%, P=0.012; DMFS 64.3% vs. 86.9%, P=0.032). Conclusions:Tumor bed irradiation for WT patients as per COG protocol can be well tolerated and achieve high efficacy. Salvage RT yields poor efficacy for tumor bed recurrence. Furthermore, tumor rupture without WAI possibly increases the abdominal and distant recurrence and the risk of death.