Using Indocyanine Green Extraction to Predict Liver Function After Stereotactic Body Radiotherapy for Hepatocellular Carcinoma
Menée auprès de 144 patients atteints d'un carcinome hépatocellulaire traité entre 2006 et 2015, cette étude évalue l'intérêt de mesurer à mi-traitement le niveau de rétention par le foie du vert d'indocyanine, un colorant administré par voie intraveineuse, pour prédire à l'aide de modèles mathématiques le niveau de préservation de la fonction hépatique après une radiothérapie corporelle stéréotaxique
Purpose : Accurate prediction of an individual patient’s risk of decreased liver function is necessary to decide which patients should be treated with SBRT and what dose they should receive. We hypothesized that mid-treatment measures of the retention of indocyanine green after 15 minutes (ICGR15) would improve the prediction of post treatment liver function.
Patients and Methods : Between 2006 and 2015, 144 patients with hepatocellular carcinoma received 175 courses of SBRT. Patient data such as age, gender, portal vein thrombosis, cirrhosis, Child Pugh (CP) score, prior liver directed therapies, and liver function tests including albumin and bilirubin (ALBI), ICG clearance, and dosimetric data such as tumor volume, and radiation dose were collected. Toxicity was evaluated as a 2-point increase in CP or a change in ALBI score at 3 months from start of SBRT. Logistic or linear regression was used to build toxicity prediction models based on patient and tumor characteristics and ICG clearance variables. Performance of the models for the binary CP outcome was summarized using AUC and ROC curves. Likelihood ratio tests were used to evaluate whether the model fit improved after incorporating the ICG variable information.
Results : In multivariable analysis age, baseline ICGR15 and change in ICGR15 were associated with toxicity defined by increased CP. . For the continuous ALBI outcome, being female, having cirrhosis, and increasing radiation dose were associated with increased toxicity. When incorporating ICGR15 into these models, an increase in ICGR15 from baseline to midtreatment was most consistently significantly associated with an increase in toxicity.
Conclusion : Incorporation of ICGR15 variables significantly improves the prediction of post SBRT liver function. The use of ICGR15 can facilitate the delivery of the maximum safe dose of radiation for patients with hepatocellular carcinoma and has the potential to improve uncomplicated tumor control and survival.
International Journal of Radiation Oncology • Biology • Physics , résumé, 2016