Comparison of contemporary methods for estimating prostate tumour volume in pathological specimens

Abstract

ObjectiveTo evaluate the accuracy of various prostate tumour volume (TV) estimation methods.To determine the most appropriate estimation method for current clinical practice. Patients and MethodsRadical prostatectomy (RP) specimens from multiple institutions were analysed by a single uro-pathologist between September 2009 and May 2011.Tumour properties including thickness, width and length were collected and TV was established using computer-assisted image analysis (CAIA).TV estimation methods including; square, cuboidal and ellipsoidal estimations were calculated using previously reported formulae.The estimation methods were compared against the 'gold-standard' and the accuracy of identifying clinically significant tumours of TV ≥0.5 cc was determined. ResultsIn all, 299 consecutive specimens were analysed by a single uropathologist.The median index TV on CAIA was 1.42 cc.Of the four estimation methods, the ellipsoid methods produced the closest correlation with the gold-standard (r 2 0.91, P = 0.71). This correlation lost accuracy when larger tumours (TV >4 cc) were excluded from the analysis (r 2 = 0.73, P = 0.003).Sensitivity and specificity for identifying clinically significant tumours was 94% and 92% respectively, when using the ellipsoid estimation. ConclusionsIn current uro-pathology, the ellipsoidal estimation method appears to be the most suitable for estimating TV in prostate cancers.This method is cheap, reproducible and sensitive and can be safely used as a surrogate for CAIA volumes when such technology is not available.

Is negative multiparametric magnetic resonance imaging really able to exclude significant prostate cancer? The real‐life experience

“…The areas of tumours were calculated using dedicated software (ImageJ, Bethesda, MD, USA). The volume between two areas of the same tumour was calculated with this formula: (B and b are the two areas, and h is 4 mm [thickness between two whole‐mount sections]): Then a tissue shrinkage correction factor of 1.12 was used for the sum of volumes. Based on this calculation clinically insignificant cancer was defined as organ‐confined disease, no Gleason pattern 4 or 5, and a cancer volume of <0.5 mL .…”

Magnetic Resonance Imaging–Transectal Ultrasound Image-fusion Biopsies Accurately Characterize the Index Tumor: Correlation with Step-sectioned Radical Prostatectomy Specimens in 135 Patients

“…For analyses of three equal trisections of the prostate, the step- [15]. Histologic tumor volume (HTV) was calculated using the simplified 3D estimation method without shrinkage correlation, as described by Perera et al [1]. Clinically significant PCa in RP specimens was defined as a cancer volume of !0.5 ml of Gleason score 6, or any Gleason score !7 [19,21,22].…”

“…However, the protocols for image-fusion prostate TB were identical in the two institutions. Lesion volume measurement using the ellipsoid method has limitations, although Perera et al demonstrated that the ellipsoid method could yield the closest results to planimetry measurements [1]. Our standardized cutting procedure for RP specimens was not prospectively designed to correspond with the validated 27-ROI schema.…”

“…Multifocality and heterogeneity of clinically localized PCa occur in 67-87% of cases [1][2][3]. In the case of multifocality, the dominant cancer lesion, or index tumor, is defined as the cancer lesion with the highest Gleason score, or the largest volume if Gleason scores are the same for more than one lesion.…”

Performance characteristics of prostate-specific antigen density and biopsy core details to predict oncological outcome in patients with intermediate to high-risk prostate cancer underwent robot-assisted radical prostatectomy

“…One specialist of urologic pathology centrally evaluated the histopathology. Prostate cancer volume was estimated from the three-dimensional measurements of the index tumor, using an ellipsoid formula without correction by a shrinkage factor due to formalin fixation [14]: major diameter × minor diameter × anteroposterior diameter × Pi/6. The anteroposterior diameter was estimated from the number of step sections of 4 mm occupied by cancer.…”