The assessment of efficacy of radionuclide therapy in patients with bone metastases after qualification based on NaF PET/CT only – Initial results

Abstract

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Objectives: It is well known that basic for radionuclide bone metastases therapy is proven metastatic disease confirmed by bone scan. Its efficacy , according to the literature, is about 80%. Because overall bone scan’s specificity is rather low it may be the reason of this efficacy. The sensitivity and specificity of PE/CT made by fluorine (NaF) is near 100% . We tried to asses the efficacy of bone metastases palliation therapy in patients whom qualification based on NaF PET/CT.

Methods: From 129 patients treated in 2006 and 2007 with samarium we selected 21 patients with bone metastases: 16 with prostate cancer 5 with other cancers. In this group the qualification to the treatment based on the ( 18F) NaF PET/CT only. PET/CT studies were made on the Siemens Biograph LSO scanner 60 min after the iv. injection of the 6 MBq/kg( 18F) NaF. The radiopharmaceutical was produced in our own laboratory. 37MBq/kg 153Sm was injected i.v. Pain was assessed before and 12 weeks after injection. Positive results were considered as pain relieving or opiates’ discontinuation.

Results: Positive results of the treatment were achieved in 17 patients - 81% (15 with prostate cancer( 93,75%), 2 with cervix cancer) The negative results were achieved in patients with prostate cancer-2, breast cancer- 1 and ovarian cancer-1.

Conclusions: 1. There could be some advantages in using NaF PET/CT as the base for therapy qualification in case of prostate cancer but the number of the patient is to low to draw final conclusions. 2. In overall population there is no difference between effects of the therapy based on bone scan and NaF PET/CT. 3. Taking into consideration higher cost of the PET/CT there is no reason to change the present way of patients qualification to this therapy.