Radiation therapy in the management of neuroblastoma: The Duke University medical center experience 1967–1984

Abstract

We have evaluated the role of radiotherapy in providing local control of primary tumors and to palliate metastases from neuroblastoma (NB). Fifty-five children with histologically verified NB were evaluated and treated from 1967 to 1984. In univariate analysis, the actuarial survival of eight children with thoracic primaries (85%) was significantly better than the survival of 39 children with intra-abdominal primaries (35%, p = 0.0287). The survival of 28 children less than or equal to 18 months of age at diagnoses was 73%, whereas 27 children older than 18 months had a survival probability of 10% ( p = 0.0001). The survival by Evans stage was: I 100% (2 patients), II 85% (7), III 60% (13), IV 4% (27) and IV-S 100% (6). According to the Pediatric Oncology Group (POG) staging system, the survival was: A 100% (3), B 66% (9), C 66% (9), D 23% (34). A multivariable analysis indicated that the Evans staging system was a more powerful indicator of prognosis than the POG system. The analysis also indicated that Evans stage and patient age were independent determinants of survival. The primary tumor site did not add significant prognostic information beyond these two factors. Children with Stage I disease were treated with surgery alone. Most children with Stages II and III disease were treated with surgery, irradiation, and Cyclophosphamide or Cyclophosphamide plus Vincristine. All seven patients with Stage 11 disease received post-operative irradiation to the primary tumor and were locally controlled with doses of 4.8 to 26.5 Gy. Eleven of the 13 patients with Stage III disease were irradiated post-operatively. Seven of these 11 patients were locally controlled with doses of 12 to 48.4 Gy. The four Stage III patients with in-field recurrences were older children with large radiotherapy fields and/or low doses administered. The Radiation Therapy Oncology Group pain score system was used to evaluate response of painful bony metastases to irradiation. A response was observed in 65% of the sites irradiated. A response was observed at 67% of the soft tissue metastases irradiated. Hepatomegaly causing respiratory embarrassment or inferior vena cava obstruction was treated with irradiation in seven patients. All patients responded with doses ranging from 5 to 24.4 Gy. Five of the 17 children who survived for more than 5 years following treatment had significant scoliosis or kyphosis secondary to vertebral body abnormalities in irradiated bones. All five children were irradiated at a young age with megavoltage equipment. Three of the five were irradiated to the full width of the vertebral body. We conclude that (a) the experience at Duke confirms previous reports that young age and early Evans stage are favorable prognostic signs in NB. (b) Stage III disease was not uniformly controlled locally by irradiation. It is not clear if this was caused by low doses or tumor biology (failures occurring in older children). (c) Post-operative wide-field irradiation and chemotherapy were used in almost all node positive (POG C) and node negative (POG B) patients. Survival in Stages B and C were equivalent. The lack of influence of nodal involvement on survival in irradiated patients is discussed.