Characterisation of indeterminate pulmonary nodules in colorectal cancer.

BACKGROUND: Management of indeterminate pulmonary nodules (IPN) in colorectal cancer (CRC) is challenging, with no clear guidance for management. We aimed to study whether certain patient and disease based factors can be used to give guidance about further investigation, treatment and outcome of these lesions. METHODS: Data was collected via a 2-year retrospective case-note review of patients discussed at the multi-disciplinary meeting with a confirmed diagnosis of CRC and IPN on CT scan. Further studies were identified by a Pubmed search with no limitations and a review of references within those papers. Pooled analysis was performed where the data was available. RESULTS: Over the two year period, 539 new cases of CRC were discussed locally. Of these, 28 (5.2%) were found to have IPN. Malignancy was more likely when multiple nodules were detected at presentation (p<0.05). Pooled analysis of a further 7 studies was performed where data was available. This confirmed the significance of multiple nodules in terms of predicting malignancy (p<0.01) and additionally demonstrated the significance of nodal disease (p<0.01). CONCLUSION: This study demonstrates the difficulties of determining the nature of IPN using either patient or tumour characteristics. Significant factors appear to be the presence of multiple nodules and nodal disease. In such cases we recommend further imaging at time of detection. If absent, we recommend an interval CT scan at six months.

Effect of epithelial and stromal edema on the light scattering properties of the cornea.

Transparency of the cornea is dependent on normal metabolism. Any disturbance in function, e.g., corneal edema, results in increased light scattering, reducing contrast sensitivity, and increasing glare susceptibility. A psychophysical method was developed to quantify this visual disability and to separate sources of light scatter within the cornea using three conditions: a no glare condition, a 30 degree angular radius glare condition, and a 3.5 degrees angular radius glare condition. Corneal edema was induced (N = 7) and contrast threshold measurements were recorded for 15 min during edema recovery using a clinically available technique. Retinal contrast attenuation was expressed in terms of light scattering factors (LSFs). Results show that the technique devised separates attenuation of retinal image contrast caused by epithelial and stromal edema and provides quantifiable values for normal light scatter and for that due to epithelial and stromal elements.