Histopathologische Qualität von Prostatastanzzylindern: Vergleich einer MR-kompatiblen Biopsienadel mit einer im Ultraschall eingesetzten ferromagnetischen Biopsienadel

Abstract

The histopathologic quality of core biopsy specimens obtained via MRI-guided prostate biopsy using a 16G MR-compatible needle was compared to that of biopsies obtained via ultrasound-guided biopsy using a conventional 18G stainless steel biopsy needle. A retrospective analysis was performed for a total of 247 transrectal prostate biopsy specimens obtained from 32 patients. A total of 117 tissue cores were obtained from 15 patients (PSA of 10.8 ng/ml, age 64 years) who underwent an MRI-guided prostate biopsy using a 16G (1.7 mm) MR-compatible biopsy needle made of titanium alloy. The remaining 130 tissue cores were obtained from 17 patients (PSA of 6.7 ng/ml, age 68 years) who underwent a transrectal ultrasound-guided prostate biopsy using an 18G (1.3 mm) ferromagnetic stainless steel biopsy needle. The length and width of the histologic sections prepared from the tissue cores were measured to calculate the area. The histopathologic quality of the specimens was assessed microscopically using tissue fragmentation, the presence of crush artifacts, and the overall accessibility as criteria. Each of these features was assigned a score from 0 to 3. All 3 features contributed equally to the overall score which ranged from 0 (no tissue) to 9 (optimal quality). The overall quality scores assigned to the biopsies obtained with a 16G MR-compatible needle and an 18G ferromagnetic needle can be considered to be equivalent to a mean difference between patient related median scores of the specimens of - 0.05 (95 % confidence interval [- 0.46; 0.36]) and a given equivalence limit of 1. The MRI biopsies showed more tissue fragmentation (p = 0.001) but fewer crush artifacts (p = 0.022) while the accessibility did not differ significantly between the two needle types (p = 0.064). There was also no significant difference in the calculated areas of the tissue cores (p = 0.236). According to the different calibers of the biopsy needles, the lengths (p = 0.008) and widths (p = 0.000) of the biopsy specimens differed significantly. The core biopsy specimens obtained with an MR-compatible 16G titanium alloy biopsy needle are of the same histopathologic quality as specimens obtained with a ferromagnetic 18G stainless steel needle.