Dual-tracer PET/CT scan after injection of combined [18 F]NaF and [18 F]FDG outperforms MRI in the detection of myeloma lesions.

The detection rates of whole-body combined [18 F]NaF/[18 F]FDG positron emission tomography combined with computed tomography (PET/CT), CT alone, whole-body magnetic resonance imaging (WB-MRI), and X-ray were prospectively studied in patients with treatment-requiring plasma cell disorders The detection rates of imaging techniques were compared, and focal lesions were classified according to their anatomic location. Twenty-six out of 30 initially included patients were assessable. The number of focal lesions detected in newly diagnosed patients (n = 13) and in relapsed patients (n = 13) were 296 and 234, respectively. The detection rate of PET/CT was significantly higher than those of WB-MRI (P < 0.05) and CT (P < 0.0001) both in patients with newly diagnosed and in those with relapsed multiple myeloma (MM). The X-ray detection rate was significantly lower than those of all other techniques, while CT detected more lesions compared with WB-MRI at diagnosis (P = 0.025). With regard to the infiltration patters, relapsed patients presented more diffuse patterns, and more focal lesions located in the limbs compared with newly diagnosed patients. In conclusion, the detection rate of [18 F]NaF/[18 F]FDG PET/CT was significantly higher than those of CT, MRI, and X-ray, while the detection rate of X-rays was significantly lower than those of all other imaging techniques except for focal lesions located in the skull.

¹8F-fluoride PET/CT for assessing bone involvement in prostate and breast cancers.

OBJECTIVE: To evaluate the accuracy of ¹8F-fluoride PET/computed tomography (CT) to detect bone metastases (BMs) in a breast and prostate cancer population, using magnetic resonance imaging (MRI) or thin-slice CT as a gold standard. METHODS: We have prospectively included 34 patients with breast (N=24) or prostate cancer (N=10) at high risk of BMs. Whole-body PET/CT (low-dose CT) and bone scintigraphy (BS) with single photon emission CT were obtained for all 34 patients and the results compared with a radiological gold standard. RESULTS: Out of the 386 foci detected by PET/CT, 219 (56.7%) could be verified by CT or MRI. Eighty-six additional foci were detected by BS (n=46) or seen only by CT (n=9), MRI (n=23), or both CT and MRI (n=8). The total number of verified lesions was therefore 274 (58.1%), including 119 (43.4%) benign and 155 (56.6%) BM. The sensitivity, specificity, and accuracy of ¹8F-fluoride PET/CT were 76, 84.2, and 80%, respectively. For BS, they were 44.8, 79.2, and 60%, respectively. Sensitivity significantly decreased for the lytic lesions. The accuracy of PET/CT was significantly superior to BS for pelvic and lumbar lesions. PET/CT provided a correct diagnosis (M+/M0) in 32 of 33 patients (one false positive) compared with 28 of 33 with BS (four false positive, one false positive). CONCLUSION: ¹8F-fluoride PET/CT is significantly more accurate than BS for detecting BMs from breast and prostate cancers.

Liver Metastases.

Many imaging techniques are available to evaluate metastatic spread to the liver. This article discusses the diagnostic performances of ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography and the dual modality PET/CT. Comparative data will be highlighted, and an attempt at defining new diagnostic algorithm will be made.