Evaluation of stage 4 neuroblastoma patients by means of MIBG and 99mTc-MDP scintigraphy.

Abstract

In a group of 22 patients with a stage 4 neuroblastoma, MIBG and 99mTc-MDP scintigraphy and radiological skeletal survey were performed at diagnosis to assess the presence of metastatic skeletal disease. In 20 out of 22 patients the MIBG scan was repeated during follow-up at a time when maximum tumoral regression was expected, i.e. after 3-4 cycles of chemotherapy; scan results were correlated to clinical and laboratory data. At diagnosis MIBG scan showed bone involvement in 19/22 patients, 99mTc-MDP in 20/22 and radiological skeletal survey in 11/22. In 1 patient only marrow aspirate revealed diffusion of disease beyond the primitive lesion. A total of 117/161 (72%) bone lesions were detected by MIBG, 89/161 (55%) by 99mTc-MDP and 47/161 (29%) by radiological skeletal survey. MIBG scintigraphy revealed bone marrow involvement in 11/22 patients in whom either marrow aspirate or bone biopsy were positive. In 5 patients 14 soft tissue lesions were also discovered and all but one primitive lesion accumulated MIBG. Although MIBG scan detected a greater number of bone lesions than 99mTc-MDP, in two patients in whom MIBG scan was negative 99mTc-MDP revealed the presence of bone involvement. Therefore we conclude that 99mTc-MDP scan is necessary to fully assess bone involvement in neuroblastoma at diagnosis. When MIBG scan was repeated after chemotherapy there was a general reduction of the number of detected lesions and in 8/17 patients both bone metastases and marrow involvement could no longer be detected.(ABSTRACT TRUNCATED AT 250 WORDS)