The clinical and financial burden of nonhepatocellular carcinoma focal lesions detected during the surveillance of patients with cirrhosis

BACKGROUND AND AIMS

HCC surveillance is challenged by the detection of hepatic focal lesions (HFLs) of other types. This study aimed to describe the incidence, characteristics, outcomes, and costs of non-HCC HFL detected during surveillance.

APPROACH AND RESULTS

We retrospectively analyzed nonstandardized workup performed in French patients included in HCC surveillance programs recruited in 57 French tertiary centers (ANRS CirVir and CIRRAL cohorts, HCC 2000 trial). The overall cost of workup was evaluated, with an estimation of an average cost per patient for the entire population and per lesion detected. A total of 3295 patients were followed up for 59.8 months, 391 (11.9%) patients developed HCCs (5-year incidence: 12.1%), and 633 (19.2%) developed non-HCC HFLs (5-year incidence: 21.8%). Characterization of non-HCC HFL required a median additional of 0.7 exams per year. A total of 11.8% of non-HCC HFLs were not confirmed on recall procedures, and 19.6% of non-HCC HFLs remained undetermined. A definite diagnosis of benign liver lesions was made in 65.1%, and malignant tumors were diagnosed in 3.5%. The survival of patients with benign or undetermined non-HCC HFL was similar to that of patients who never developed any HFL (5-year survival 92% vs. 88%, p = 0.07). The average cost of the diagnostic workup was 1087€ for non-HCC HFL and €1572 for HCC.

CONCLUSIONS

Non-HCC HFLs are frequently detected in patients with cirrhosis, and do not impact prognosis, but trigger substantial costs. This burden must be considered in cost-effectiveness analyses of future personalized surveillance strategies.

In-vacuum optical isolation changes by heating in a Faraday isolator

We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient convection cooling of the magneto-optic crystal of the Faraday isolator. An isolation decrease by a factor of 10 is experimentally observed in a Faraday isolator that is used in a gravitational wave experiment (Virgo) with a 10 W input laser when going from air to vacuum. A finite element model simulation reproduces with a great accuracy the experimental data measured on Virgo and on a test bench. A first set of measurements of the thermal lensing has been used to characterize the losses of the crystal, which depend on the sample. The isolation factor measured on Virgo confirms the simulation model and the absorption losses of 0.0016 +/- 0.0002/cm for the TGG magneto-optic crystal used in the Faraday isolator.