Unenhanced whole-body MRI versus PET-CT for the detection of prostate cancer metastases after primary treatment.

OBJECTIVE: The aim of this study was to evaluate the accuracy of unenhanced whole-body MRI, including whole-body Diffusion Weighted Imaging (DWI), used as a diagnostic modality to detect  pathologic lymph nodes and skeletal metastases in patients with prostate cancer (PCa) undergoing restaging after primary treatment. PATIENTS AND METHODS: 152 male patients with biochemical recurrence after radical prostatectomy (RP) or external beam radiation therapy (EBRT) underwent MRI at a 1.5 Tesla magnet with whole spinal sagittal T2-weighted, sagittal T1-weighted, sagittal STIR images, axial T1 and T2-weighted and STIR images of the pelvis and whole-body. 18Fcholine-PET/CT exam was used as the reference standard. RESULTS: MRI protocol including whole-body combined T1-weighted+T2-weighted+STIR+DWI showed a sensitivity (Se) of 99%, a specificity (Spe) of 98%, a positive predictive value (PPV) of 98%, a negative predictive value (NPV) of 96%, an accuracy of 98% and an area under the receiver operating characteristic curve (AUC) of 0.971 for identification of bone metastatic lesion. The same protocol, displayed a Se of 98%, a Spe of 99%, a PPV of 97%, a NPV of 98%, an accuracy of 98 % and an AUC of 0.960 in the detection of pathologic lymph nodes. CONCLUSIONS: Unenhanced whole-body MRI, including whole-body-DWI, is an accurate and cost-effective diagnostic tool which is able to detect lymph node involvement and bone metastases in patients with biochemically recurrent PCa after RP or EBRT. Thanks to its lack of ionizing radiation, excellent soft tissue contrast, high spatial resolution, no need of contrast agent, high Se and Spe, it could play a role in the restaging procedure of such patients.

Incidental discovery of testicular microlithiasis: what is the importance of ultrasound surveillance? Two case reports.

Many studies have demonstrated an association between diffuse bilateral testicular microlithiasis (TM) and gonadal and extragonadal germ cell tumors. Nevertheless, it is still uncertain whether ultrasound surveillance is really necessary in patients with TM in the absence of other risk factors such as previous testicular cancer, a history of cryptorchidism or testicular atrophy. We report the cases of a 33- and a 39-year-old man presenting with a retroperitoneal extragonadal tumor. The first patient underwent an MRI examination in order to rule out a lumbosacral hernia: MRI images showed no slipped disks but a voluminous retroperitoneal solid mass. The histological analysis revealed an immature teratoma. The second patient came to the emergency department complaining of abdominal pain, vomiting, weight loss and mild jaundice: ultrasound examination showed a large, ill-defined heterogeneous abdominal mass, confirmed by CT and MRI examination. The histology diagnosed a yolk sac tumor. In both patients, the testicular sonography was performed to rule out a focal lesion, but it displayed bilateral TM without a focal testicular mass. Based on our direct experience, we highlight the importance of annual ultrasonographic surveillance of the testis and the retroperitoneal space in patients with occasionally detected TM.