Multi-parametric magnetic resonance imaging (mpMRI) may identify radio-recurrent intra-prostatic cancer accurately. We aimed to compare visually directed MRI-targeted biopsies (MRI-TB) to an accurate reference standard - transperineal prostate mapping (TPM) biopsies with 5 mm sampling - in the detection of clinically significant cancer in men with biochemical failure after radiotherapy.
A retrospective registry analysis between 2006 and 2014 identified 77 men who had undergone mpMRI followed by MRI-TB and TPM. Clinical significance was set at two definitions of disease. Definition 1 was Gleason ≥ 4+3 and/or maximum cancer core length ≥ 6 mm. Definition 2 was Gleason ≥ 3+4 and/or maximum cancer core length ≥ 4 mm.
Of the 77 patients included, the mean age was 70 years (range 61-82; standard deviation 5.03). The median prostate-specific antigen (PSA) at the time of external beam radiotherapy (EBRT) was 14 ng/ml (interquartile range 7.83-32.50). The most frequent EBRT dose given was 74 Gy over 37 fractions. Eight patients had iodine-seed implant brachytherapy or high dose rate brachytherapy. Neoadjuvant/adjuvant hormonal therapy use was reported in 38. The time from EBRT to biochemical recurrence was a median of 60 months (interquartile range 36.75-85.00). The median PSA at the time of mpMRI was 4.68 ng/ml (interquartile range 2.68-7.60). The median time between mpMRI and biopsy was 2.76 months (interquartile range 1.58-4.34). In total, 2392 TPM and 381 MRI-TB cores were taken with 18% and 50% cancer detection, respectively. Detection rates of definition 1 clinically significant cancer were 52/77 (68%) versus 55/77 (71%) for MRI-TB and TPM, respectively. MRI-TB was more efficient requiring 1 core versus 2.8 cores to detect definition 2 cancer.
MRI-TB seems to have encouraging detection rates for clinically significant cancer with fewer cores compared with TPM, although TPM had higher detection rates for smaller lower grade lesions.
Clinical oncology (Royal College of Radiologists (Great Britain)). 2016 Jun 15 [Epub ahead of print]
A Kanthabalan, M Abd-Alazeez, M Arya, C Allen, A Freeman, C Jameson, A Kirkham, A V Mitra, H Payne, S Punwani, N Ramachandran, M Walkden, M Emberton, H U Ahmed
Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK. Electronic address: ., Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK; Faculty of Medicine, Fayoum University, Fayoum, Egypt., Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Histopathology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Histopathology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Clinical Oncology University College London Hospitals NHS Foundation Trust, London, UK., Department of Clinical Oncology University College London Hospitals NHS Foundation Trust, London, UK., Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK; Department of Histopathology, University College London Hospitals NHS Foundation Trust, London, UK; Centre for Medical Imaging, Division of Medicine, University College London, London, UK., Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK., Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK., Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK., Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.