Is there a correlation between Prostate Specific Antigen (PSA) and imaging modalities that may aid in detecting disease progression in patients with prostate cancer post prostatectomy?

Objectives: The purpose of this retrospective review is to suggest which imaging modality is best suitable for a patient with elevated PSA. Various imaging is performed on patients with history of prostate cancer who have undergone a prostatectomy but have rising PSA levels in their blood work. Typically, the use of imaging modalities used to try and localize the site of PSA can include a combination of CT chest-abdomen-pelvis, MRI pelvic-whole body, nuclear medicine bone scan, and PET/CT. Newer advances in diagnostic imaging could be suggestive to which course of action should be taken to localize PSA in tissue, based on a patients PSA.

Methods: Chart reviews will be conducted at my clinical site on patients who have a history of prostate cancer and have had a prostatectomy. I will assess PSA level, imaging results and biopsy results when applicable.

Results: In a similar retrospective study, a chart review was conducted on 142 patients with a history of prostate cancer who underwent a prostatectomy and now have an elevating PSA level. The median PSA level among these patients was 0.21 ng/ml. Imaging results for this population revealed a greater association between high PSA levels and positive imaging outcomes. Pelvic MRI was performed on all patients and was positive 15/142 patients, the median PSA level in these 15 patients was 0.18 ng/ml. Of these 15 patients, 14 patients showed recurrence in the prostate bed, 1 showed pelvic osseous metastasis. Biopsies were performed in the prostate bed on 5/14 of these patients and 4/5 were positive for recurrence. The 127 patients who received negative MRI results, 54/127 underwent additional imaging. 1/28 patients had a positive NM bone scan with a negative biopsy. 0/18 patients had a positive CT. 0/14 patients had a positive whole-body MRI. 1/4 patients had a positive 18-F FDG PET study with a negative biopsy result. The median PSA level of patients with negative imaging findings was 0.14 ng/ml (2). The above-mentioned study was conducted in 2016. Since 2016, 18-F-fluciclovine has been FDA approve for localization of PSA in tissue using PET/CT. The study mentioned does not include data since 18-F-fluciclovine was approve for clinical use in PET/CT. With this advancement, I predict my collected data will show PSA in tissue could be better localized in patients with a lower elevation in PSA. These advances could be suggestive to which imaging exam future patients would benefit more from based on their level of PSA.

Conclusions: A retrospective review revealed in 142 patients, imaging is more successful when PSA levels are higher. Local recurrence was identified on 14/142 patients and distant metastatic disease was located on 1/142. The study reviewed was conducted in 2016. Since there have been a number of advances in diagnostic imaging since the above-mentioned study was concluded, I predict present imaging exams are more sensitive to patients who have a lower elevation in PSA. “18-F-fluciclovine PET/CT, which was found to have a high sensitivity and specificity of 92.5% and 90.1% for the focus of primary disease” (1). Chart reviews will be completed at my clinical site following IRB approval and the results will be ready to present at the annual meeting. Works Cited 1. Parent, E. E., Schuster, M. D. (2018). Update on 18-F-fluciclovine PET for prostate cancer imaging. Journal of Nuclear Medicine. 2. Vargas, H. A., Martin-Malburet, A. G., Takeda, T., Corradi, R. B., Eastham, J., Wibmer, A., Sala, E., Zelefsky, M. J., Weber, W. A., ⋯ Hricak, H. (2016). Localizing sites of disease in patients with rising serum prostate-specific antigen up to 1ng/ml following prostatectomy: How much information can conventional imaging provide? Urologic oncology, 34(11), 482.e5-482.e10.