[Radiologic diagnosis of bone metastases recurrence in patients with prostate cancer treated strontium-89]

Aiming to evaluate efficiency of 89SrCl (Metastron) in patients with metastatic lesion of the skeleton in prostate cancer we have performed a follow-up scintigraphy of the skeleton with 99mTc-methylendiphosphonate (MDP) and MRI with quantitative study of metastatic foci. 12 patients with prostate cancer (on the average 11 +/- 6 bone metastases were examined using scintigraphy of the skeleton with 99mTc-MDP and MRI study in T1, T2 and proton density modes. Investigations were performed before injected as a single dose of 150 MBq (4 mCi). At all the stages there was made a quantitative study of foci of pathological uptake of 99mTc-MDP compromising numbers of foci, focus parameters, intensity of 99mTc-MDP accumulation in the pathological part relatively the contralateral region as well as quantification of MRI signals from metastatic areas in signal intensity units. In 3 month 4 patients with extensive metastatic skeletal lesion (> 12) showed a considerable decrease of number of foci of pathological 99mTc-MDP uptake (on average to 6 +/- 3). In the remained metastatic foci there was noted a decrease of dimensions and 99mTc-MDP uptake intensity at an average by 29.8 +/- 15%, improvement in T1 intensity by 113 +/- 55.6 units. In 2 patients who initially presented a "superscan" pattern on 99mTc-MDP bone scintigraphy the 89SrCl treatment converted this of low intensity had demonstrated their complete regression. Results of radiologic follow-up of bone metastases in prostate cancer using MRI and bone scintigraphy with 99mTc-MDP argue that systemic radiotherapy with 89SrCl induces significant regress of metastatic process that involves all volume of the metastases.