The complementary role of sequential ^99mTc-MDP and ⁶⁷Ga-citrate scanning in the diagnosis and follow-up of neuroblastoma

Abstract

Fourteen children with histopathologically confirmed neuroblastoma underwent 38 studies using ^99mTc-methylene-diphosphonate (MDP) and galliumcitrate Ga67 whole-body scintigraphy during various stages of the disease. Ten patients (71%) showed ^99mTc-MDP accumulation in the primary tumoral site, whereas 11 patients (78.6%) showed ⁶⁷Ga concentration. In 12 patients (86%), at least one of these two radiopharmaceuticals concentrated in the primary tumor. Nine patients had osseous or extraosseous metastases. All of these metastases (100%) were positive on ^99mTc-MDP sctintigraphy. No ⁶⁷Ga-citrate uptake was demonstrable in osseous metastases; only one extraosseous lung metastasis concentrated this radiopharmaceutical. ⁶⁷Ga-citrate was superior to ^99mTc-MDP with regard to accurately demonstrating the extent of primary tumors. Only ^99mTc-MDP indicated the relationship of the tumor to the kidneys and neighbouring osseous structures, prividing early screening of kidney compression and possible damage caused by the tumor. From these results, we found these two methods to be complementary for the diagnosis and follow-up of neuroblastoma; their combined use resulted in high diagnostic accuracy and a considerable gain of information. We therefore recommend sequential ^99mTc-MDP and ⁶⁷Ga-citrate scans for the diagnosis and evaluation of the primary tumor; periodic ^99mTc-MDP wholebody scans should be used in the follow-up of treatment, and for discovering disease exacerbations and metastases.