Prospective diagnostic test accuracy comparison of computed tomography during arterial portography and Primovist magnetic resonance imaging in the pre-operative assessment of colorectal cancer liver metastases.

OBJECTIVES: To assess and compare the accuracy and inter-observer agreement for the detection of liver lesions using Primovist magnetic resonance imaging (pMRI) and computed tomography during arterial portography (CTAP). METHODS: Patients evaluated at St George Hospital Liver Unit for colorectal liver metastases (CRCLM) underwent CTAP as part of standard staging. pMRI was added to the pre-operative assessment. Two radiologists reported CTAP and two reported pMRI. The sensitivity and specificity of CTAP and pMRI were calculated using histopathology as the gold standard. RESULTS: Complete data were available for 62 patients corresponding to 219 lesions confirmed on histopathology. Agreement on the detection of lesions between the two radiologists that reported pMRI was higher than for CTAP (Kappa = 0.80 versus 0.74). Specificity of lesion detection for pMRI was 0.88 and 0.83 for CTAP (P = 0.112). Sensitivity for pMRI was 0.83 and 0.81 for CTAP. For patients who had chemotherapy before evaluation, pMRI had a significantly higher specificity than CTAP (0.79 versus 0.63, P = 0.011). CONCLUSIONS: pMRI is less invasive, has a good inter-observer agreement, has comparable sensitivity and specificity to CTAP in the pre-chemotherapy population and demonstrates better specificity in patients assessed post-chemotherapy. pMRI is a valid alternative to CTAP in the assessment of CRCLM.

Tumor thickness influences prognosis of T1 and T2 oral cavity cancer--but what thickness?

BACKGROUND: Previous studies have demonstrated that tumor thickness might influence prognosis in oral cancer, but the significant point at which outcome changes has varied from 1.5 mm to 6 mm. The clinical relevance of thickness remains unclear, and a reproducible prognostic "breakpoint" needs to be defined. METHODS: Tumor thickness was measured in 145 oral cavity squamous cancers, clinically staged T1 (n = 62) or T2 (n = 83). Clinical and pathologic data were collected prospectively between 1988 and 2000, but thickness was measured on paraffin sections for this study. Minimum follow-up was 2 years, and thickness was correlated with local control, cervical node involvement, and survival. Patients with clinically positive nodes (n = 21) were not excluded. Overall, 55 patients had pathologic node involvement at some time in their disease. RESULTS: Median tumor thickness was 6.2 mm, and there was little variation between sites: tongue, 6.4 mm; floor of mouth, 6.6 mm; and other sites, 5.7 mm. Median thickness for T1 tumors was 4.3 mm, significantly less than the T2 group, 8 mm (p <.01). Median thickness also varied significantly for tumors with associated nodal disease (8.5 mm) and without nodal disease (5.8 mm) (p <.01). Prognosis changed significantly at a cutoff of 4 mm with local control, nodal disease, and survival rates of 91%, 8%, and 100%, respectively, for tumors <4 mm compared with 84%, 48%, and 74% for those 4 mm or more thick (p <.01). Subgrouping greater than and less than 3 mm and 5 mm also showed a difference but with poorer discrimination. Thickness and pathologic nodal involvement were highly significant independent prognostic factors. CONCLUSIONS: Tumor thickness is a highly significant, objectively measurable prognostic factor in early stage oral cancers. There is a need to standardize techniques of measurement to allow a multi-institutional study to be carried out. This will facilitate the development of strategies aimed at improving the outcome of higher risk patients.