Transitions of Liver and Biliary Enzymes during Proton Beam Therapy for Hepatocellular Carcinoma

Abstract

<jats:p>Proton beam therapy (PBT) is a curative treatment for hepatocellular carcinoma (HCC), because it can preserve liver function due to dose targeting via the Bragg peak. However, the degree of direct liver damage by PBT is unclear. In this study, we retrospectively analyzed liver/biliary enzymes and total bilirubin (T-Bil) as markers of direct liver damage during and early after PBT in 300 patients. The levels of these enzymes and bilirubin were almost stable throughout the treatment period. In patients with normal pretreatment levels, aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), and T-Bil were abnormally elevated in only 2 (1.2%), 1 (0.4%), 0, 2 (1.2%), and 8 (3.5%) patients, respectively, and in 8 of these 13 patients (61.5%) the elevations were temporary. In patients with abnormal pretreatment levels, the levels tended to decrease during PBT. GGT and T-Bil were elevated by 1.62 and 1.57 times in patients who received 66 Gy (RBE) in 10 fractions and 74 Gy (RBE) in 37 fractions, respectively, but again these changes were temporary. These results suggest that direct damage to normal liver caused by PBT is minimal, even if a patient has abnormal pretreatment enzyme levels.</jats:p>

Proton Beam Therapy for Multifocal Hepatocellular Carcinoma (HCC) Showing Complete Response in Pathological Anatomy After Liver Transplantation

“…In contrast, PBT has a unique dose distribution defined by the Bragg peak, allowing the sparing of normal tissues and focusing the dose on the tumor area [28]. Sumiya et al showed that PBT can protect against and prevent deterioration of liver function through accurate targeting, based on the almost constant levels of liver/biliary enzymes and total bilirubin (T-Bil) related to liver function during PBT, and minimal direct damage to the normal liver even in cases with abnormal pre-treatment enzyme levels [29]. A review at the University of Tsukuba [18] showed that PBT has superior therapeutic performance and encompasses a wide range of indications for HCC, including large tumors, tumor thrombosis, and cases with poor liver function.…”

Proton Therapy in the Management of Hepatocellular Carcinoma

“…A retrospective analysis of 300 patients with HCC noted only minor, transient variations in liver and biliary enzymes over the course of PBT [ 63 ]. Another retrospective analysis observed radiologic biliary abnormalities in only 7.2% of patients undergoing PBT with doses of 75 Gy RBE and above.…”