Pentavalent 99mTc DMSA: uptake into a variety of human rhabdomyosarcoma xenografts.

BACKGROUND

Rhabdomyosarcoma is a common soft tissue sarcoma of childhood. While Ga is currently the most accurate modality for imaging residual or recurrent tumour its dosimetry is unfavourable. Pentavalent 99mTc DMSA [99mTc (V) DMSA] has been shown to accumulate in this tumour in a limited number of clinical cases.

METHODS

Biodistribution of 99mTc (V) DMSA was determined in non-tumour bearing BALB-C mice. Operative specimens from four clinically 67Ga avid tumours were xenografted into nude mice and allowed to reach a significant size. Biodistribution studies were performed after the injection of 99mTc (V) DMSA in all animals and 125I HSA and 67Ga in a limited number of animals.

RESULTS

None of the tumours investigated demonstrated significant 99mTc (V) DMSA accumulation. Biodistribution was identical in tumour and non-tumour bearing animals.

CONCLUSIONS

Rhabdomyo-sarcoma xenografts do not demonstrate significant uptake of 99mTc (V) DMSA.