MRI sensitivity in detecting macroscopic local recurrences in prostate cancer:an observational study
PO-1489
Abstract
MRI sensitivity in detecting macroscopic local recurrences in prostate cancer:an observational study
Authors: Letizia Cavallini1, Caterina Gaudiano2, Alessandra Arcelli3, Erika Galietta1, Filippo Mammini1, Daria Vallerossa1, Viola Laghi1, Silvia Paolinelli1, Elena Natoli1, Giorgio Tolento3, Silvia Cammelli1, Alessio Giuseppe Morganti1, Maria Ntreta3
1Radiation Oncology, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Alma Mater Studiorum University of Bologna, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 2Department of Radiology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 3Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
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Purpose or Objective
Biochemical recurrence of prostate cancer after radical prostatectomy are recorded in approximately 15 to 30% of cases. Treatment options are represented by salvage radiotherapy (SRT), hormonal therapy, or observation with PSA level monitoring. In patients eligible for SRT, current guidelines recommend PSMA PET to exclude distant metastases. An observational study of our centre (ICAROS) was carried out to evaluate a possible role of MRI before SRT. Aim of this report was to describe the preliminary results.
Material and Methods
Over a 4-year period, all patients eligible to SRT without contraindications to MRI underwent clinical and instrumental examination including pelvic multi-parametric MRI with endorectal coil, possibly associated with choline or PSMA PET. The following data were prospectively collected: PSA at biochemical relapse, PSA doubling time, ISUP score, SRT treatment plan, site and of any macroscopic recurrence, outcome.
Results
Fifty-eight patients were evaluated in this study. Median age was 64 years (range: 41-78), median PSA level at biochemical recurrence was 0.66 ng/ml (range: 0.12-6.24), and most patients (68.9%) had ISUP 3-5. Pre-SRT MRI was positive for local recurrence in 40/58 patients (68.9%), for pelvic nodal metastases in 1/58 (1.7%), and for pelvic bone metastases in 1/58 (1.7%). The site of local recurrence was as follows: bladder neck 30/42 (71.4%), vesicourethral anastomosis 7/42 (16.7%), rectovesical space 2/42 (4.8%), prostatic fossa 1/42 (2.4%). Twenty-eight patients (66.7%) with positive MRI also underwent choline or PSMA PET. Of these, only 9 patients (21.4%) showed the same uptake at the same sites as evidenced by MRI. Conversely, in 19 patients (45.2%) MRI results did not match the PET result.
Conclusion
An unexpectedly high rate of macroscopic local relapse was recorded in a cohort of patients with biochemical recurrence after radical prostatectomy and prospectively assessed with MRI. These results challenge current recommendations on the most appropriate imaging exams in this clinical setting.