PSMA-PET/CT provided superior detection of prostate cancer lesions with better sensitivity than mpMRI. PSMA-PET/CT can be used to enhance locoregional mpMRI to provide improved detection and characterization of lesions.

The novel Gallium-68 prostate-specific membrane antigen (PSMA)-bis [2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-diacetic acid positron emission tomography (PET) tracer is increasingly used in the evaluation of prostate cancer, particularly in the detection of recurrent disease. However, PSMA is expressed in nonprostatic tissues, as well as in other pathologic conditions. Here we illustrate such interpretive pitfalls with relevant images that one may encounter while reporting PSMA PET/CT. This study aims to show variation in physiological distribution of PSMA activity and uptake in various benign and neoplastic disorders that may be misinterpreted as prostatic metastatic disease. These pitfalls are illustrated to enhance awareness, aiding a more accurate interpretation of the study. Retrospective database of all (68)Ga PSMA PET/CT was created and reviewed. In total, 1115 PSMA PET/CT studies performed between February 27, 2015, and May 31, 2017, were reviewed. Any unusual uptake of PSMA was documented, described, and followed up. All cases were then subdivided into the following 4 categories: physiological uptake, benign pathological uptake, nonprostatic neoplastic uptake, and miscellaneous uptake. A variety of nonprostatic tissues and lesions, including accessory salivary gland, celiac ganglion, gall bladder, Paget's bone disease, reactive lymph nodes, non–small cell lung cancer, renal cell cancer, and neuroendocrine tumor, were found to show PSMA uptake. PSMA uptake is not prostate-specific and can be taken up physiologically and pathologically in nonprostatic tissue. It is important for reporting physicians to recognize these findings and instigate appropriate investigations when required while avoiding unnecessary procedures in physiological variation.

A 71-year-old man with a background of treated stage IIIB non-small cell lung cancer was referred for Ga prostate-specific membrane antigen (PSMA) PET/CT for staging of prostate cancer. In addition to the PSMA uptake in the known prostate malignancy, the study also demonstrated increased PSMA uptake in an enlarging left lower lobe lung mass with diffusely increased PSMA uptake in an enlarged thyroid gland and bilateral enlarged supraclavicular lymph nodes. Fine-needle aspiration biopsy of the thyroid gland and a left supraclavicular lymph node demonstrated metastatic adenocarcinoma from a primary lung cancer.

Ga-PSMA PET/CT is increasingly used to evaluate recurrent prostatic malignancy due to its high specificity. A 75-year-old man with a previous history of treated prostate cancer 3 years earlier presented with rising prostate-specific antigen (PSA) level and underwent Ga-PSMA PET/CT which demonstrated a PSMA-avid focus in the neck of the pancreas. Triple-phase abdominal CT demonstrated enhancement in the arterial phase and to a lesser extent the venous phase of a soft tissue mass in the neck of the pancreas. Cytological and histopathological examination of the soft tissue mass confirmed a low-grade pancreatic neuroendocrine tumor.

Ga-prostate-specific membrane antigen (PSMA) PET/CT is increasingly used to evaluate recurrent prostatic malignancy due to its high specificity. A 56-year-old man with previous history of treated prostate cancer 4 years earlier presented with rising prostate-specific antigen level and underwent Ga-PSMA PET/CT, which demonstrated an enlarging pulmonary nodule without PSMA avidity. The pulmonary nodule, however, showed moderate uptake on a corresponding FDG PET/CT study, suspicious of primary lung malignancy. Cytological and histopathological examination of the pulmonary nodule confirmed a metastatic deposit from ductal prostatic adenocarcinoma, an uncommon variant of prostatic malignancy.

A 33-year-old woman with McCune-Albright syndrome was referred for a Ga-DOTATATE PET/CT study for evaluation and staging of a biopsy-proven pancreatic tail neuroendocrine tumor. The scan demonstrated intense focal octreopeptide uptake corresponding to the known neuroendocrine tumor at the pancreatic tail/splenic hilum. There was no evidence of octreopeptide-avid metastases. Diffuse octreopeptide uptake was demonstrated in multiple bones involving the right side of the skeleton. The concurrent CT demonstrated corresponding expansile lucent changes consistent with the known fibrous dysplasia.

INTRODUCTION AND OBJECTIVES: Current standard of care for prostate cancer detection is multiparametric MRI (mpMRI) and biopsy prior to active treatment. In recent years, prostate-specific membrane antigen (PSMA) ligands have been used in positron emission tomography (PET) to target prostate cancer cells for detection, however guidelines on its use are limited by its infancy. PSMA PET is a highly sensitive and specific scan that has been primarily used in detecting prostate cancer recurrence. PSMA PET may be combined with computed tomography (CT) or MRI, although few centres have access to PET/MRI machines. There is a growing role for PSMA PET/CT in primary staging. We aimed to examine how PSMA PET/CT could contribute to current standards of care by comparing mpMRI and PSMA PET/CT to prostatectomy histopathology.METHODS: We conducted a chart review from February 2015 to January 2017 of 50 male patients staged for prostate cancer using PSMA PET/CT and mpMRI who then underwent radical prostatectomy. Pre-operative PSMA PET/CT and mpMRI were paired with their corresponding histological tumor.RESULTS: A total of 50 male patients were included in this study, with a mean age of 64.9 years (AE 5.6), and PSA of 10.6 (AE 8.1). The median time between PSMA PET/CT and surgery was 5 weeks (range 0-21 weeks), and the median time between mpMRI and surgery was 18 weeks (IQR 13-25 weeks). The median time between mpMRI and PSMA PET/CT was 12 weeks (IQR 3-12.25 weeks). A total of 81 lesions were confirmed by histopathology. Fifty index lesions were confirmed by histopathology, all of which were detected by PSMA PET/ CT and 47 by mpMRI (100% vs. 94%). Thirty-one secondary lesions were confirmed by histopathology, 29 of which were detected by PSMA PET/CT and 16 by mpMRI (93.5% vs. 51.6%). PSMA had better sensitivity for index lesion localization than mpMRI (81.1% vs. 64.8%). Specificity was similar for PSMA PET/CT and mpMRI (84.6% vs. 82.7%). Forty-five patients (90%) were found to have multifocal disease on histopathology. PSMA predicted multifocal disease in 43 (86%) of patients (88.9% sensitivity, 40.0% specificity); mpMRI predicted multifocal disease poorly (10% sensitivity, 10% specificity).CONCLUSIONS: PSMA-PET/CT provided superior detection of prostate cancer lesions with better sensitivity than mpMRI. PSMA-PET/ CT can be used to enhance locoregional mpMRI to provide improved detection and characterization of lesions.

Background: Intrapulmonary percussive ventilation is used in various clinical settings to promote secretion clearance, reverse or treat atelectasis and improve gas exchange. Despite a few studies reporting the use of intrapulmonary percussive ventilation in critical care, the available data remain insufficient, contributing to weaker evidence toward its effectiveness. Also, there is a paucity of studies evaluating the safety and feasibility of intrapulmonary percussive ventilation application in critical care. This retrospective pilot study has evaluated the safety and feasibility of intrapulmonary percussive ventilation intervention in non-intubated patients admitted to an intensive care unit. Methods: The medical records of 35 subjects were reviewed, including 22 subjects who received intrapulmonary percussive ventilation intervention and 13 subjects matched for age, sex, and primary diagnosis who received chest physiotherapy. The records were audited for feasibility, safety, changes in oxygen saturation, chest X-ray changes, and intensive care unit length of stay. Results: A total of 104 treatment sessions (IPV 65 and CPT 39) were delivered to subjects admitted with a range of respiratory conditions in critical care. Subjects completed 97% of IPV sessions. No major adverse events were reported with intrapulmonary percussive ventilation intervention. Intensive care unit length of stay in the intrapulmonary percussive ventilation group was 9.6 AE 6 days, and in the CPT group, it was 11 AE 9 days (p ¼ 0.59). Peripheral oxygen saturation pre to post intervention was 92% AE 4 to 96% AE 4 in IPV group and 95% AE 4 to 95% AE 3 in the CPT group. Conclusion: Application of intrapulmonary percussive ventilation intervention was feasible and safe in non-ventilated adult patients in critical care.