Transrectal ultrasound‐guided biopsy of prostate voxels identified as suspicious of malignancy on three‐dimensional ¹H MR spectroscopic imaging in patients with abnormal digital rectal examination or raised prostate specific antigen level of 4–10 ng/ml

Abstract

Results of the evaluation of transrectal ultrasound (TRUS) guided needle biopsy of voxels identified as suspicious of malignancy on magnetic resonance spectroscopic imaging (MRSI) in a large cohort of men (n = 83) with abnormal digital rectal examination (DRE) [prostate specific antigen (PSA) 0-4 ng/ml] or PSA less than 10 ng/ml, are reported. Three-dimensional (1)H MRSI was carried out at 1.5 T using a pelvic-phased array coil in combination with an endorectal surface coil. Voxels were classified as suspicious of malignancy based on Cit/(Cho + Cr) metabolite ratio. TRUS-guided biopsy of suspicious voxels was performed using the z- and x-coordinates obtained from MR images and two to three cores were taken from the suspected site. A systematic sextant biopsy was also carried out. MRSI showed voxels suspicious of malignancy in 44 patients while biopsy revealed cancer in 11 patients (25%). Patients who were negative for malignancy on MRSI were also negative on biopsy. An overall sensitivity of 100%, specificity of 54%, negative predictive value of 100% and accuracy of 60% were obtained. The site of biopsy was confirmed (n = 20) as a hypo-intense area on repeat MRI while repeat MRSI revealed high choline and low citrate. The overall success rate of MRI-directed TRUS-guided biopsy of 25% was higher compared with a 9% success rate achieved without MR guidance in another group of 120 patients. Our results indicate that TRUS-guided biopsy of suspicious area identified as malignant from MRSI can be performed using the coordinates of the voxel derived from MR images. This increases the detection rate of prostate cancer in men with PSA level <10 ng/ml or abnormal DRE and also demonstrates the potential of MR in routine clinical practice.

Role of magnetic resonance methods in the evaluation of prostate cancer: an Indian perspective

“…Our MRSI data [136] showed voxels suspicious of malignancy in 44 patients, while biopsy revealed cancer in 11 patients (25%). Patients whose biopsy was negative showed negative for malignancy on MRSI.…”

“…Recently, many researchers have reported the use of MRSI to target needle biopsies under TRUS guidance for detection of prostate malignancy in patients with negative TRUS biopsy [120,[133][134][135]. Targeted biopsies may improve the diagnostic yield even more than increasing the number of biopsies [126] We recently reported 3D MRSI-directed TRUS-guided needle biopsy of voxels suspicious of malignancy found on MRSI in 83 men with abnormal DRE and with PSA level less than 10 ng/ml [136]. Voxels were identified as positive or negative for malignancy based on Cit/(Cho + Cr) metabolite ratio (<1.4 for positive) as reported in literature [89,110,137].…”

Prostat Kanserinin Degerlendirilmesinde 3 T Difuzyon Agirlikli MR Goruntuleme

“…MR spektroskopi görüntüleme veya dinamik kontrastlı MR incelemesi, hasta tekrar biyopsiyi almadan önce prostat kanseri saptamada yardımcı olduğu bildirilmiştir [44,45]. Buna karşılık, daha önce negatif olan biyopsi sonuçlarına sahip hastalarda prostat kanseri tespiti için 3T DAG 'nin etkinliği hakkında çok az çalış-ma yayınlanmıştır.…”

“…Prostat DAG, prostat kanseri olan hastaların değerlendirilmesinde faydalı olabilse de, hem 1,5 hem de 3T'de mevcut prostat DAG'inin halen üstesinden gelmesi gereken birkaç sınır-laması vardır [1,45].…”

Role of Endorectal Prostate MRI in Patients with Initial Suspicion of Prostate Cancer

“…However, the sensitivity of conventional endorectal prostate MRI in this subset of patients precludes the use of MRI alone in these patients and makes it necessary to closely monitor (e. g. by PSA testing) those who do not undergo prostate biopsy, regardless of their MRI findings. The sensitivity of conventional endorectal prostate MRI might be improved in the future by the supplementary use of newer techniques such as DWI, DCE-MRI, and 1 H-MRS [9, 26,27]. Once adequate sensitivity can be achieved with MRI, MRI findings can be used to plan targeted biopsies, thus contributing to a marked reduction of core biopsies in the future.…”