ABSTRACT
Introduction@#18F-PSMA-1007 is a novel prostate-specific membrane antigen (PSMA)-based radiopharmaceutical for imaging prostate cancer. The recommended imaging time is 60 minutes post-injection of the radiotracer. However, during this time there is a physiologic accumulation of the radiotracer in the urinary bladder which sometimes may obscure lesions adjacent to it. @*Objective@#This study aims to determine if early dynamic imaging in addition to the recommended 60-minute postinjection static imaging can improve the detection of PSMA-avid lesions in the staging and restaging of prostate cancer. @*Methods@#This is a retrospective cross-sectional study of the detection rate of early dynamic and static imaging using 18F-PSMA-1007 PET/CT scan in patients with prostate cancer (PCa) who were referred for initial staging or restaging. The McNemar test was used to compare the detection rate between the two imaging. Spearman correlation was used to determine the correlation of Gleason score (GS), PSA, and SUVmax values.@*Results@#18F-PSMA-1007 PET/CT scans of 53 patients with prostate cancer, were referred for either staging (22/53) or restaging (31/53), all of whom had undergone both early dynamic and static imaging. Among the 53 patients, 5 had 2 lesions each, for a total of 58 lesions were included in the analysis. There were 48/58 lesions detected on both early dynamic and static imaging, 2/58 lesions were only detected in the early imaging, 1/58 lesions was only detected in the static imaging, and 7/58 were not detected on both imaging. McNemar the test was not statistically significant (p = 1.000) in the detection rate of the two methods. There is a positive correlation between serum PSA levels and SUVmax measurements for all the patients. Only the correlation between the GS and SUVmax in the static imaging of the staging group was statistically significant. @*Conclusion@#Early dynamic imaging may be an adjunctive procedure in detecting PSMA-avid lesions, particularly in the basal segment of the prostate gland near the urinary bladder. However, it is not recommended as a standard component of the comprehensive protocol for imaging using 18F-PSMA-1007 PET/CT in patients with PCa.
Subject(s)
Prostatic NeoplasmsABSTRACT
@#Primary malignant melanoma of the esophagus (PMME) is an exceptionally rare condition, representing a mere 0.1 to 0.2% of esophageal cancers, and accounting for just 0.1 to 0.5% of all melanomas. This case involves a 39 -year-old Filipino male who sought medical attention after an episode of choking. Subsequently, endoscopy with biopsy revealed a mass in the distal third of the esophagus, ultimately diagnosed as PMME based on histopathology and immunohistochemistry. FDG-PET/CT scan revealed a hypermetabolic distal esophageal mass and a confluent upper paratracheal lymphadenopathy. He was initially treated with Pembrolizumab, Nivolumab, and Ipilimumab immunotherapy. However, post-treatment FDG PET/CT scans unveiled metabolic progression of the esophageal mass with new hypermetabolic cervical lymph nodes, necessitating a shift to carboplatin and paclitaxel chemotherapy. After two cycles, there was a notable metabolic regression of the mass and paratracheal node with metabolic resolution of the cervical lymph node. An additional 2 cycles of chemotherapy were given, aimed to further reduce the size of the tumor, however, a succeeding follow-up study revealed metabolic progression of the mass. Surgical resection of both the esophageal mass and paratracheal nodes became imperative. The aggressive characteristics, metastasis at early diagnosis, and lack of effective treatment have contributed to the poor prognosis of PMME. Total esophagectomy is the preferred method of treatment. Chemotherapy and immunotherapy may be used in advanced diseases but with variable efficacy. The utilization of FDG PET/CT scans plays a crucial role in both the initial staging and the ongoing assessment of treatment response in patients diagnosed with PMME. This advanced imaging modality offers valuable insights into the extent of the disease and aids clinicians in evaluating the effectiveness of the chosen therapeutic interventions. Given the rarity and challenges associated with PMME, a multidisciplinary approach integrating surgical, medical, and imaging strategies is essential for comprehensive patient care.