Evaluation of magnetic resonance imaging for bladder cancer detection following transurethral resection of bladder tumour (TURBT).

PURPOSE: To evaluate the performance of MRI for detection of bladder cancer following transurethral resection of bladder tumour (TURBT). METHODS: This single-centre retrospective study included forty-one consecutive patients with bladder cancer who underwent bladder MRI after TURBT. Two uroradiologists retrospectively assessed the presence of tumour using bladder MRI with and without DWI (diffusion weighted imaging) using a five-point Likert scale. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated and inter-reader agreement was assessed. Histopathology was used as the reference standard. RESULTS: 24 out of 41 patients (58.5%) had no residual tumour or Tis (carcinoma in situ) after TURBT. Sensitivity, specificity, PPV and NPV for detection of tumour using T1WI (T1-weighted imaging) and T2WI (T2-weighted imaging) was 50.0%, 54.6%, 21.1%, and 81.8%, respectively and for T1WI, T2WI and DWI combined was 100%, 76.5%, 50.0% and 100%, respectively. Overestimation of tumour was more common than underestimation. MRI showed high accuracy for patients in whom there was no residual tumour (78.9%). Inter-reader agreement for tumour detection improved from fair (κ = 0.54) to moderate (κ = 0.70) when DWI was included. CONCLUSION: Non-contrast MRI with DWI showed high sensitivity and relatively high specificity for detection of residual tumour after TURBT. Inter-reader agreement improved from fair to moderate with the addition of DWI. MRI can be useful after TURBT in order to guide further management.

Evaluation of a multiparametric MRI scoring system for histopathologic treatment response following preoperative chemoradiotherapy for rectal cancer.

PURPOSE: To evaluate the performance of a multiparametric (mp) MRI scoring system for assessment of tumour response in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (CRT). METHOD: Fifty-nine consecutive patients with LARC who had rectal MRI before and after CRT followed by surgery were included. Two radiologists retrospectively assessed tumour response using a proposed mpMRI scoring system. Treatment response was classified as complete, near complete, partial or poor. Accuracy, sensitivity, specificity, positive predictive value and negative predictive values were calculated and inter-reader agreements were assessed. Pathologic tumour regression grade (pTRG) was the reference standard. RESULTS: Treatment response was correctly predicted by both readers in 32.2%-40.7% of patients. Overestimation was more common than underestimation. Sensitivity, specificity, PPV and NPV for pathologic complete response (pCR) among both readers was 16.7-33.0 %, 88.7-94.2 %, 14.3-40.0 % and 92.5-94.2 % respectively. Sensitivity and PPV for both readers improved to 56.0-60.0 % and 53.6-66.7 % respectively when complete response and near complete response categories (good responders) were combined. Inter-reader agreement using the scoring system was fair (κ = 0.383). Agreement between mpMRI score and pathological tumour response was poor to fair for both readers (κ = 0.050 to 0.258) but improved when complete and near complete response categories (good responders) were combined (κ = 0.214 to 0.362). CONCLUSIONS: Despite low agreement between radiological tumour response and pTRG, the proposed mpMRI-based scoring system appears useful in identifying good responders who may benefit from nonoperative management strategies.

Endometriosis: a rare cause of small bowel obstruction.

Although endometriosis is a common condition in young women, symptomatic involvement of the small bowel is rare. The authors report the case of a 44-year-old lady initially thought to have irritable bowel syndrome who presented 1 month later with acute small bowel obstruction. A CT scan showed small bowel dilatation with a transition point in the ileum, but no distinct lesion. The patient had an exploratory laparotomy where an obstructing lesion in the terminal ileum and several enlarged mesenteric lymph nodes were identified. Consequently, a right hemicolectomy was performed. Pathology specimens showed multiple endometriotic foci in the bowel with stricturing of terminal ileum and appendiceal intussusception. This likely resulted in subocclusive episodes and intestinal obstruction. This case highlights the difficulty in establishing a preoperative diagnosis of endometriosis. Small bowel endometriosis should, therefore, be considered in the differential diagnosis of women of childbearing age who present with symptoms of obstruction.