Radiation Oncology/Prostate/Workup

Endorectal Magnetic Resonance Imaging

 * On axial T1 gland appears homogeneous and the zonal anatomy is not well appreciated
 * Postbiopsy hemorrhage is evident on T1-weighted images as high T1 signal intensity (important because hemorrhage may mimic tumor on T2 and greatly interferes with assessment of ECE)
 * zonal anatomy is best seen on axial and coronal T2 as are the vas deferens and SV
 * neurovascular bundles best seen on axials
 * penile root is better imaged on T2 coronals
 * peripheral zone is hyperintense whereas tumor appears is HYPOINTENSE (other causes of low T2: hemorrhage, prostatitis, hormone treatment, and RT)
 * Hemorrhage: high T1, low T2

Bone Metastases Detection

 * Brussels, 2007 (Belgium) PMID 17664475 -- "Magnetic resonance imaging of the axial skeleton for detecting bone metastases in patients with high-risk prostate cancer: diagnostic and cost-effectiveness and comparison with current detection strategies." (Lecouvet FE, J Clin Oncol. 2007 Aug 1;25(22):3281-7.)
 * Prospective. 66 patients with high-risk PCA (newly diagnosed PCA with GS >=8 and PSA >=20; PSA recurrence after RP with PSADT <12 months; on ADT and PSADT <12 months). Evaluated by bone scan + targetedplain films (BS/TXR) vs. bone scan + targeted plain films + MRI-on request (BS/TXR/MRIor) vs. axial MRI (MRIas)
 * Outcome: 62% bone mets. MRIas more sensitive than current sequence of sequential workup (bone scan, targeted XR, MRI of area at risk)

Role of Bone Scan

 * ""Columbia University, 2000"" PMID 11121646 -- "Which patients with newly diagnosed prostate cancer need a radionuclide bone scan? An analysis based on 631 patients" (Lee, N, Int J Radiat Oncol Biol Phys. 2000 vol. 48 (5) pp. 1443-6)
 * Retrospective review of 631 consecutive patients treated at Columbia Presbyterian Medical Center between 1990-1996 who had both a Gleason score and a bone scan. Reviewed clinical factors associated with positive bone scan.
 * Results: 14% with positive bone scan. Multivariate analysis: only Gleason 8-10, PSA>50, and clinical T-category >T2b predicted positive bone scan. All 237 patients with Gleason 2-7, PSA<15 and T-category50, 49.5% had positive bone scan.