Outcome of radiotherapy for metastatic neuroblastoma

Abstract

Background. Neuroblastoma (NB) is a prevalent solid extracranial tumor that primarily affects children. It is the third most common type of cancer in children, following leukemia and brain tumors. Aim. The study aimed to discuss the clinical outcomes after adjuvant radiotherapy to the primary site in case of metastatic NB after good response to chemotherapy. Methods. A retrospective clinical-dosimetric study of 25 patients metastatic NB treated with radiotherapy at Baghdad Radiotherapy and Nuclear Medicine Center, at Baghdad Medical City Complex, Baghdad, Iraq. Data collection begin from December 2023 and March 2024. Data were collected retrospectively with review of records. The following variables were studied: sex, age, date of diagnosis, site of primary tumor, site of metastasis, chemotherapy, surgery, RT, RT sites, doses of RT, fractions of RT, recurrence sites, date of relapse and survival outcome for each patient. Follow-up period include look up to metastasis, site of metastasis, recurrence, site of recurrence and survival rates. Results. In relation to sex, males (14, 56%) were more than females (11, 44%). The mean age of NB cases was 45.64±17.6 months. In NB, suprarenal masses were the most common site of primary in 21 (84%) of patients. The most common site of metastasis of NB was bone marrow in 12 (48). The multi sites of recurrence was the commonest presentation in 48%. The relapse-free survival (RFS) was 22.38 months. 5 out of 25 patients were alive whereas 20 (80%) of cases were dead. The median follow-up time was 6 years, and the OS of NB in this study after optimal treatment was 2.46 years (95%CI= 1.705-3.21) for survivors. The MS was 4.84 years. The OS was 6 yrs for those diagnosed at 2017, 2 yrs for those diagnosed at 2018, 1.5 yrs for those diagnosed at 2019, 1.75 yrs for those diagnosed at 2020, 3 yrs for those diagnosed at 2021 and 1.5 yrs for those diagnosed at 2022. There was a significant difference among doses (Log Rank (Mantel-Cox)= 11.425, p=0.044). Conclusions. This study is the first study in Iraq that examines the clinical results of radiotherapy on the primary site in cases of metastatic neuroblastoma following induction chemotherapy. The suprarenal masses of neuroblastoma are the most often occurring main site. The primary sites of metastases for neuroblastoma (NB) are the bone marrow and bones. Timely detection and proactive treatment of NB can improve overall results. Reoccurrence of skeletal issues and the infiltration of bone marrow are frequently observed. There were no significant differences observed in terms of relapse-free survival and overall survival based on factors such as sex, age, location of the main tumor, chemotherapy, radiation treatment, surgery, and radiation therapy dosages.