preventive effect of enoxaparin, pentoxifylline and ursodeoxycholic acid to radiation induced liver toxicity

Conditions: Colorectal Cancer; Liver Metastases; Irradiation Damage; Radiation Induced Liver Disease

Summary: to evaluate whether a combination regimen of pentoxifylline, ursodeoxycholic acid and enoxaparin provides a protective effect on the liver parenchyma after high dose rate (hdr) brachytherapy.

a preventive effect of pentoxifylline, ursodeoxycholic acid and low dose low molecular weight heparin on pathological processes in healthy tissue after irradiation is described in clinical studies on percutaneous liver irradiation and on bone marrow transplantation. however, data remains inconclusive. this exploratory study aims at assessing whether a protective effect of the combination of pentoxifylline, ursodeoxycholic acid and enoxaparin can be demonstrated in a limited number of patients with liver metastases of colorectal cancer after hdr brachytherapy. all patients receive a single fraction ct/mri-guided hdr-brachytherapy of colorectal liver metastases using iridium-192 as a standard therapy. the follow-up consists of 4 mri controls of the abdomen using the hepatocyte-specific contrast agent gd-eob-dtpa (primovist) after 3 days, 6 weeks, 3 months and 6 months as well as blood samples and a questionnaire taken the same time.within the study, 22 patients are given low dose low molecular weight heparin, pentoxifylline and ursodeoxycholic acid for 8 weeks starting with the preinterventional day. another 22 patient will receive the standard therapy without the medication. after completion of the follow-up, mri volume data of the lesion will be acquired and compared to the dosimetric treatment plan. blood samples are tested for liver-specific and inflammatory laboratory parameters.

Eligibility criteria:
inclusion criteria: * age 18 to 80 * if female, postmenopausal or surgically sterilized * liver metastases from colorectal carcinoma scheduled for a ct/mri-guided single-fraction interstitial hdr brachytherapy * non-cirrhotic liver * life expectancy longer than 6 months * willing and able to undergo all study procedures * having voluntarily provided written and fully informed consent exclusion criteria: * women who are pregnant, lactating or who are of childbearing potential * liver cirrhosis * hepatitis b * hepatitis c * patients being clinically unstable * uncooperative, in the investigator's opinion * having been previously enrolled in this study * participating in another therapy-modulating clinical trial * contraindication for mri * contraindication or hypersensitivity to one or more components of gd-eob-dtpa, enoxaparin, ursodeoxycholic acid and/or pentoxifylline * any prior irradiation therapy of the liver * close affiliation with the investigational site; e.g. a close relative of the investigator * severe coronary artery disease * autoimmune diseases * acute bacterial endocarditis * active major bleedings and high rish of uncontrolled haemorrhage * patients with severe or moderate renal impairment (gfr below 60 ml/min/1.73 m2 according to the mdrd or cockroft-gault formula, calculated from a creatinine value obtained within 1 week before each planned primovist-enhanced mr examination)

Keywords: brachytherapy liver metastases irradiation radiation induced liver disease dosimetry