How accurately can multiparametric magnetic resonance imaging measure the tumour volume of a prostate cancer? Results of a systematic review

Abstract

Summary The tumour volume of a cancer within the prostate gland is commonly measured with multiparametric MRI. The measurement has a role in many clinical scenarios including focal therapy, but the accuracy of it has never been systematically reviewed. We included articles if they compared tumour volume measurements obtained by mpMRI with a reference volume measurement obtained after radical prostatectomy. Correlation and concordance statistics were summarised. A simple accuracy score was derived by dividing the given mean or median mpMRI volume by the histopathological reference volume. Factors affecting the accuracy were noted. Scores for potential bias and quality were calculated for each article. A total of 18 articles describing 1438 patients were identified. Nine articles gave Pearson’s correlation scores, with a median value of 0.75 but the range was wide (0.42–0.97). A total of 11 articles reported mean values for volume while 9 reported median values. For all 18 articles, the mean or median values for MRI volumes were lower than the corresponding reference values suggesting consistent underestimation. For articles reporting mean and median values for volume, the median accuracy scores were 0.83 and 0.80, respectively. The accuracy was higher for tumours of greater volume, higher grade and when an endorectal coil was used. Accuracy did not seem to improve over time, with a 3 Tesla magnet or by applying a shrinkage factor to the reference measurement. Most studies showed evidence of at least moderate bias, and their quality was highly variable, but neither of these appeared to affect accuracy.

Prediction and Mapping of Intraprostatic Tumor Extent with Artificial Intelligence

“…Precision management of PCa has the potential to optimize therapy while preserving quality of life, but targeted treatment first requires accurate tumor localization. PI-RADS ROIs are known to underestimate tumor extent [8] , [9] , [10] , and in our study, treatment of the original ROI would have resulted in positive margins for every patient. It is clear that current multiparametric MRI contouring protocols, which were developed for diagnosis, are not suitable for targeted treatment.…”

“…Leveraging a variety of ablative technologies [2] , [3] , [4] , [5] , [6] , FT has the potential to preserve quality of life while conferring metastasis-free and overall survival rates comparable with radical prostatectomy [7] . Most FT studies rely upon magnetic resonance imaging (MRI) to identify and delineate PCa foci, but MRI-visible regions of interest (ROIs) consistently underestimate the true size and extent of PCa [8] , [9] , [10] . Thus, treatment margins beyond MRI-visible tumor boundaries are critical to the success of FT.…”

Comparison of prostate volume measured by transabdominal ultrasound and MRI with the radical prostatectomy specimen volume: a retrospective observational study

“…Bezinque et al reported an excellent correlation between the PV calculated by the ellipsoid formula and MRI-R3D (manual segmentation by a radiologist) (ICC = 0.90), indicating that MRI using the ellipsoid formula provided an accurate measurement of PV [ 19 ]. In conclusion, PV estimation on MRI using the ellipsoid formula was a rapid technique with reasonable accuracy and reproducibility, and its general availability made it feasible for routine clinical use [ 23 ]. As in previous studies, our results demonstrated that the specimen volume for the entire cohort was highly associated with and underestimated by the volume measured by MRI [ 24 , 25 ].…”

Can contralateral lymph-node metastases be ruled out in prostate cancer patients with only unilaterally positive prostate biopsy?

“…However, our data reflect the current situation whereby magnetic resonance imaging is not yet a diagnostic standard in prostate cancer care. Furthermore, there is accumulating evidence for the underestimation of prostate cancer expansion by multiparametric magnetic resonance imaging [ 27 ].…”