Prospective assessment of MRI for imaging retroperitoneal metastases from testicular germ cell tumours.

AIM: To determine the sensitivity of magnetic resonance imaging (MRI) in the detection of retroperitoneal lymph nodes in patients with testicular germ cell tumours (TGCT). METHODS AND MATERIALS: A prospective study of 52 patients (mean age 34 years, range 18-54 years) was performed. Imaging of the retroperitoneum was performed using multidetector computed tomography (CT) and 1.5 T MRI systems. The CT and MRI images were read independently by three observers. The number, size, and site of enlarged nodes (> or =10 mm maximum short axis diameter) were recorded. Retroperitoneal nodal detection on MRI was compared to CT. RESULTS: Twenty-two (42%) of the 52 patients had no retroperitoneal disease; in remaining 30 patients 51 enlarged nodes were identified. On a per patient basis readers 1, 2, and 3 identified nodal disease in 28 of 29, 29 of 30, and 24 of 30 patients, respectively, using MRI compared to CT. Thus for experienced radiologists (readers 1 and 2) MRI is comparable to CT for nodal detection (i.e., this study excludes MRI being inferior to CT with 80% power and 5% type 1 error). CONCLUSION: MRI offers an alternative method for staging the retroperitoneum in young patients being followed for TGCT and has the major advantage of avoiding exposure to ionizing radiation.

CT detection of hydronephrosis in resected colorectal cancer: a predictor of recurrent disease.

AIM: To investigate the causes and significance of hydronephrosis in follow-up of colorectal cancer. METHODS AND MATERIALS: Case notes and serial computed tomography (CT) examinations were reviewed of 75 patients (250 CT examinations) after resection for colorectal cancer in whom hydronephrosis developed on follow-up. RESULTS: The most common cause of hydronephrosis was a focal plaque-like mass centred on the peritoneum, demonstrated in 37 cases (49%). Patients with R1 (microscopic residual tumour) or R2 (macroscopic residual tumour) disease developed hydronephrosis at a median time of 13 months (90% CI: 9-18 months) compared with 22 months (90% CI: 17-26 months) for those having (R0) curative resection. Patients with pT4 invasion of peritoneum or adjacent organs developed hydronephrosis at a median of 14 months (90% CI: 6-16 months) compared with a median of 22 months in patients with pT3 tumours (90% CI: 11-27 months). Of 26 patients without an obvious cause of hydronephrosis on initial CT examination, follow-up CT demonstrated a definite mass lesion in 50%. Median survival after the onset of hydronephrosis was 6 months (range 1-34 months) with a 1-year mortality of 62%. CONCLUSIONS: Hydronephrosis is an important early indicator of colorectal cancer recurrence, even in the absence of a mass.