Keywords:
Oncology, Urinary Tract / Bladder, MR, Ultrasound, Biopsy, Cancer
Authors:
S. J. Pattiarachchi, W. Thambavitage, M. Lozinskiy, Y. Yuminaga, Y. Weerakkody; Perth, WA/AU
DOI:
10.26044/ranzcr2021/R-0469
Results
A total of 98 cases were biopsied with the preceding MRI reporting:
- a lesion greater than PI-RADS 3 in 78 (79.6 %) cases
- a lesion greater than PI-RADS 4 in 61 (62.2 %) cases.
- a lesion of PI-RADS 5 in 28 (28.6 %) cases.
Of the 98 biopsied cases, a positive histology result for a tumour of Gleason 6 or above was present in 71 % of cases.
In 15 of the 78 cases (19.2 %) having lesions reported as PI-RADS 3 or above on MRI, had a distinct sonographic correspondance. 63 of the 78 MRI suspected cases (80.7 %) did not show a distinct lesion on ultrasound. These cases had cognitive targeted sampling to a position approximately matching the clock face location of the suspected lesion on the MRI scan.
Positive histology (Gleason 6 or above) for a core aimed at or adjacent (taken as one clock face location within the reported lesion) to a target lesion on MRI was present in 93 % of cases.
Approximately 9.8 % (6/61) of patients who had an MRI score of PI-RADS 4 or above had negative results on all cores.
Around 29.6 % (29/98) of cases had a histology result positive for tumour (Gleason 6 or above) outside the region of the suspected lesion on MRI (when located > 1 clock face position outside or beyond).
Our study had a few limitations which include:
- When target positivity was assessed, a positive hit rate was taken as a core positive for a tumour within 1 clock face position around the target lesion. As the boundaries of the clock face are not clear cut, this carries some level of subjectivity.
- Clock face assessment towards the apex becomes even less accurate as all clock positions tend to converge/cluster.
- Interobserver variation in reporting of MRI (some of the MRI scans were reported outside our institution).
- Small sample size