Extracapsular Extension

July 19, 2012

MRI-guided biopsy can solve a diagnostic dilemma in patients with elevated or rising PSA with negative trans-rectal ultrasound-guided (TRUS) biopsy. In this case study, a 70 year-old man presented with a clinical history of elevated, persistently rising PSA (table 1 below).He had undergone two TRUS biopsy sessions in May 2008 and April 2011. Both were negative. His prostate gland measured 4.6 x 3.9 x 3.5 = 33 cc gland volume.

Figure 1. A: DCE with parametric overlay; B.Kinetic curve; C. T1 Axial; D. Subtraction

Figure 2. A. DWI Axial; B.T2 Axial; C. T2 Sagittal; D.T2 CoronalFindings: At MR imaging, there was a 3.1 cm area in the ventral transition zone (TZ) which demonstrated evidence of abnormally decreased T2 signal, restricted diffusion (figure 1) and suspicious (wash-in/wash-out) contrast kinetics (figure 2), findings compatible with prostate cancer (PCa). No gross invasion of the neurovascular bundles (NVBs), periprostatic venous plexus or seminal vesicles (SVs) was seen. There was no evidence of pelvic lymphadenopathy nor were there signal abnormalities in the visualized marrow spaces.The large lesion in the TZ extended beyond the capsule; however, there was no evidence of bony or distant metastatic disease. Staging was T3a, N0, M0.

This case represents an excellent example of a situation where a lesion detected with MRI was also biopsied under MRI guidance (figure 3).Figure 3. A.Axial needle confirmation; B.Axial T2; C. DynaLOC planning software; D. Sagittal calibration scanWhen the patient returned for his MRI-guided biopsy, only four cores were obtained, all positive for adenocarcinoma and Perineural invasion (table 2, below).LocationGleason ScoreTumor Size% Cancer InvolvementLeft Base Lateral8 (4+4)13.6mm85%Left Base Medial8 (4+4)17mm100%Right Base Medial8 (4+4)14mm100%Right Base Lateral8 (4+4)14mm100%Dan Sperling, MD, president and CEO, Sperling Prostate Center; medical director, New Jersey Institute of Radiology