Bone imaging with⁹⁹Tc^mpolyphosphate: a comparison with¹⁸F and skeletal radiography

Abstract

A comparative study of 18F as fluoride, 99Tcm-polyphosphate (TcPP) and radiology for detecting metastases in patients with cancer is reported. Ninety patients were studied using 18F and TcPP and 96 lesions were detected in the views included in the comparison. 99 per cent of the lesions were detected using TcPP and 56 per cent using 18F. There was only one site where the l8F was positive and the TcPP equivocal and none where the 18F scan was positive and TcPP negative. Radiographs or reports on the radiographs were available on 74 of the patients and showed that radiological changes were only seen in 29 per cent (20/70) of the lesions detected by scanning. In six special situations radiological changes were seen but no lesions were reported from the isotope studies. Blood and urine measurements and serial scintigrams were carried out on a small number of patients and they indicate that the optimum time for scanning with TcPP is three to five hours after injection. It is concluded that TcPP is a superior bone scanning agent to 18F and that, although all lesions should be X-rayed, only in certain special cases should further radiological investigation be necessary in the management of cancer patients.