Fig. 29
From: Post-treatment MRI aspects of photodynamic therapy for prostate cancer
Mismatch. PSA increase in a patient treated by left photodynamic therapy 1 year earlier. MRI was performed: axial T2 (a), axial ADC (b) and axial T1 dynamic contrast-enhanced (c) MR images show a suspicious left median focus with T2 hyposignal, early enhancement and mild diffusion restriction on ADC map (arrowhead). The location of suspicious lesion seen on MRI is indicated on a prostate map. Targeted biopsy was performed with TRUS. Pathology slide at high magnification (d) shows a 1-mm tumour focus in a scar tissue. Crushed appearance of several glands (circled), suspect, confirmed by immunohistochemical study, and surrounded by thick collagen fibres (fibrous scar). The nodule on MRI corresponds to the scar tissue; the tumour focus is too small to be seen on MRI