E2483. Sites of Post Prostatectomy Recurrence on Multiparametric Pelvic Magnetic Resonance Imaging with Endorectal Coil
  1. Diana Kaya; UT Texas MD Anderson Cancer Center
  2. Cihan Duran; UT Texas Health Science Center; UT Texas MD Anderson Cancer Center
  3. Usama Salem; UT Texas MD Anderson Cancer Center
  4. Jia Sun; UT Texas Health Science Center; UT Texas MD Anderson Cancer Center
  5. Vikas Kundra; UT Texas Health Science Center; UT Texas MD Anderson Cancer Center
We aimed to investigate different anatomical sites of prostate cancer (PCa) recurrence on mutliparametric magnetic resonance imaging (mpMRI) in patients with PCa who had biochemical recurrence following prostatectomy, and investigate correlation of recurrence site with prostate specific antigen (PSA) at the time of mpMRI scan and Gleason score at the time of prostatectomy.

Materials and Methods:
Retrospective review of 1416 mpMRI scanned in 2010-2017 for biochemical recurrence following prostatectomy yielded 255 patients with positive for recurrent disease imaging findings on mpMRI. Presence of recurrent disease was confirmed by biopsy, radiologically abnormal lymph nodes or bone lesions, or clinical disposition. Specific sites of recurrent disease were correlated with PSA at the time of MRI scan and Gleason score at surgery.

Mean PSA for recurrence at prostatectomy bed was 2.3±4.5 ng/ml, lymph node metastasis 3.0±5.9 ng/ml and bone metastases 23.8±77.0 ng/ml. Most of recurrences in the prostatectomy bed occurred in perianastomotic location (49.6%). Rising level of PSA was correlated with trend towards having more lymph node and bone metastases using the Kruskal-Wallis Test (p = .0018). In all patients with PSA>40 ng/ml, bone metastases were found. Increasing Gleason score was associated with less frequent prostatectomy bed recurrences and higher incidence of lymph node and bone metastasis using a chi-square test (p = .017) (Figure 1). There was a distinction in biological behavior between Gleason 3+4 and 4+3 PCa; Gleason 4+3 recurrent tumors demonstrate features of Gleason 8,9 or 10 with more frequent metastasis to lymph nodes and bones and less frequent recurrences in prostatectomy bed whereas Gleason 3+4 distribution was different from Gleason 8, 9 or 10.

PSA and Gleason score are associated with sites of recurrence and Gleason 3+4 appear to have more prostatectomy bed and less bone metastases.