Prostate cancer is the most frequently diagnosed cancer in males and the second leading cause of cancer-related death in men. Assessment of prostate cancer can be divided into detection, localization, and staging; accurate assessment is a prerequisite for optimal clinical management and therapy selection. Magnetic resonance (MR) imaging has been shown to be of particular help in localization and staging of prostate cancer. Traditional prostate MR imaging has been based on morphologic imaging with standard T1-weighted and T2-weighted sequences, which has limited accuracy. Recent advances include additional functional and physiologic MR imaging techniques (diffusionweighted imaging, MR spectroscopy, and perfusion imaging), which allow extension of the obtainable information beyond anatomic assessment. Multiparametric MR imaging provides the highest accuracy in diagnosis and staging of prostate cancer. In addition, improvements in MR imaging hardware and software (3-T vs 1.5-T imaging) continue to improve spatial and temporal resolution and the signal-to-noise ratio of MR imaging examinations. Another recent advancement in the field is MR imaging guidance for targeted prostate biopsy, which is an alternative to the current standard of transrectal ultrasonographyguided systematic biopsy. Abbreviations: ADC = apparent diffusion coefficient, BPH = benign prostatic hyperplasia, DCE = dynamic contrast-enhanced, DRE = digital rectal examination, EES = extracellular-extravascular space, PSA = prostate-specific antigen, ROI = region of interest, SNR = signal-to-noise ratio, TKCM = tracer kinetic compartmental model

A radionuclide methodology and reference values have been developed for a single gastrointestinal transit study including esophageal transit, liquid and solid gastric emptying, and small-and largebowel transit, using 111 In-diethylenetriaminepentaacetic acid (DTPA) with the standardized 99m Tc-labeled solid meal. Methods: Eighteen healthy subjects and 18 patients were investigated. The esophageal transit study was performed with 3.7 MBq (0.1 mCi) of 111 In-DTPA in 15 mL of water. A liquid-only 30-min gastric-emptying study followed, with ingestion of 3.7 MBq (0.1 mCi) of 111 In-DTPA in 300 mL of water. Then, a simultaneous solid-liquid emptying study was acquired after ingestion of a solid 99m Tc-sulfur colloid-labeled meal and 7.4 MBq (0.2 mCi) of 111 In-DTPA in 120 mL of water. Images were acquired intermittently for 4 h. Additional 111 In images were acquired at 5 and 6 h to measure small-bowel transit, and at 24, 48, and 72 h for largebowel transit. Results: Reference values were determined for esophageal transit (transit time, percentage emptying at 10 s), liquid-only gastric emptying (emptying half-time), liquid and solid emptying in a dual-phase solid-liquid study (emptying half-time and percentage emptying at 1, 2, 3, and 4 h), small-bowel transit index (percentage transit to ileocecal valve at 6 h), and colonic transit (geometric center and percentage colonic emptying) at 24, 48, and 72 h. Results from the first 18 patients found abnormal transit in 72% (13/18); clinical management changed in 61% (11/18). Conclusion: We have developed a radionuclide methodology and derived reference values for a comprehensive gastrointestinal transit study using 111 In-DTPA with the standardized 99m Tc-labeled solid meal. Our initial clinical experience suggests clinical value.

Gallium-68 DOTATATE provides physiologic imaging and assists in disease localization for somatostatin receptor (SSTR) positive neuroendocrine tumor (NET) patients. However, questions regarding usefulness of gallium-68 DOTATATE imaging in identifying the primary site in neuroendocrine tumors (NETS) of unknown primary, correlation of NET grade with median Standardized Uptake Value (SUV) and effects of long acting somatostatin analog on gallium-68 DOTATATE imaging quality needs to be evaluated. A single institution retrospective review of the first 200 NET patients with gallium-68 DOTATATE imaging from Dec 2016 to Dec 2017 was conducted. Questions related to NETs of unknown primary, correlation of Standardized Uptake Value (SUV) to Ki-67 (which signifies proliferation rate), the effects of long-acting systemic somatostatin analog (SSA) on SUV were part of our data analysis. From these 200 patients, 59.5% (119) were females, 40.5% (81) were males; the median age was 62 years. The following primary tumor sites were identified: small bowel-37.5%; pancreas-18.5%; bronchial-14%; colon-3.5%; rectum-2%; appendix-1.5%; adrenal-0.5%; prostate-0.5%; others-3% and unknown primary-19%. Mean hepatic SUV of the lesion with the greatest radiolabeled uptake in 96 patients was similar irrespective to exposure to long acting SSA. Patients exposed to long acting SSA had mean SUV of 31.3 vs 27.8 for SSA naïve patients. The difference was not statistically significant. Gallium-68 DOTATATE imaging seems to distinguished G3 NET from G1/G2 based on mean SUV, and also identified the primary tumor site in 17 of 38 (45%) patients with unknown primary. Systemic exposure to long acting SSA does not appear to influence mean SUV of gallium-68 DOTATATE scan.

Solitary fibrous tumor (SFT) is an uncommon neoplasm first described as a tumor of mesenchymal origin that rarely involves the liver. This report presents a rare case of unresectable SFT of the liver and documents the first use of transarterial chemoembolization in its treatment. Three sessions of chemoembolization were performed aiming to reduce the tumor size or at least stabilize it. Subsequent follow-up magnetic resonance imaging examinations were performed to assess imaging response to treatment. We recommend further studies to be done to assess both the use of transarterial chemoembolization in the treatment of unresectable SFT and the use of contrast-enhanced and diffusion-weighted magnetic resonance imaging for assessment of the tumor response to treatment.