2509 Role of EUS in Prostate Cancer Recurrence

Abstract

INTRODUCTION: We describe the first documented case of the use of EUS for evaluation, biopsy, and placement of fiducial markers in the same setting by an advanced interventional endoscopist for recurrent prostate cancer. CASE DESCRIPTION/METHODS: A 56 yrs old Caucasian male with history of prostate cancer status post radical robotic prostatectomy in 2008. The pathology revealed moderately differentiated adenocarcinoma with focal mucinous change, Gleason Score 7. Stage T3a N0 M0. The right posterolateral 6 mm superficial to the apex, capsular incision were positive. Zero of the nine lymph nodes removed were positive. His post op PSA remained low till January of 2015. The PSA starts to show an upward trend from May 2017 and rose to 2.07 ng/ml in December 2017. He didn't have any clinical complaints. A PET scan in January 2018 was negative for recurrence. An MRI in February 2018 showed some enhancement of soft tissue in the prostatic bed favoring post-surgical changes (Figure 1). The patient was referred for EUS due to concerns regarding the rising PSA levels. We used a radial EUS to evaluate the prostatic bed, which was difficult due to post prostatectomy echogenic artifact. However we noticed a slightly prominent hypoechoic area in the prostatic bed (Figure 2). We then used a linear EUS scope (Figure 3) and a 22G core needle to biopsy this area, which on touch prep cytology was positive for adenocarcinoma. We then placed fiducial markers in the surgical bed under EUS guidance. Patient then underwent radiotherapy with complete response to treatment. DISCUSSION: Any rising PSA levels of any magnitude (biochemical recurrence) should be followed and evaluated further after prostatectomy to ensure complete cure of prostate cancer. Although different imaging modalities are available to tackle these issues, they lack specificity. It's a common practice to place fiducials in a prostate cancer prior to radiation treatment. The role of EUS in the surveillance and diagnosis of patients after prostatectomy has not been validated. Once patient undergo prostatectomy or radiation, the prostatic bed develop significant fibrosis. This is a challenge for future radiological imaging to identify the recurrent disease. A rising PSA level of any is worrisome in a prostatectomy patient and EUS guided FNB of the prostatic bed will be a great tool to issue accusation and, confirming the diagnosis. Furthermore the fiducials can be placed in the same session for stereotactic salvage radiation with limited peripheral injury.