Abstract
Biliary tract cancers, encompassing gallbladder cancer, intrahepatic cholangiocarcinoma
(IHCC), and extrahepatic cholangiocarcinoma (EHCC), are rare malignancies with limited
prospective studies guiding their management. Radiation therapy has evolved significantly
over the years, advancing from conventional fractionated approaches to innovative
modalities such as stereotactic body radiation therapy (SBRT) and hypofractionated
radiation therapy. This review explores the role of radiation therapy in biliary tract
cancers, with a particular focus on IHCC and EHCC, highlighting its historical evolution,
current applications, and future directions. For IHCC, external beam radiation therapy
has demonstrated benefits in retrospective analyses, with modern conformal techniques
such as intensity-modulated radiation therapy and volumetric modulated arc therapy
enabling safe dose escalation and improved local control. SBRT and hypofractionated
radiation therapy offer promising alternatives for unresectable or recurrent IHCC,
with high local control rates and manageable toxicity profiles reported in retrospective
and early-phase prospective studies. Despite these advancements, the need for robust
phase III comparative trials remains critical. In EHCC, radiation therapy plays a
pivotal role in adjuvant and definitive settings. Additionally, radiation therapy
is increasingly utilized as part of neoadjuvant protocols for liver transplantation
candidates with unresectable hilar cholangiocarcinoma, improving outcomes when combined
with strict selection criteria and modern systemic therapies. This review underscores
the importance of a multidisciplinary approach to the management of biliary tract
cancers, integrating radiation therapy advancements with systemic and surgical therapies.
Future research should focus on personalized treatment strategies, leveraging novel
technologies and biomarker-driven approaches to optimize outcomes for this challenging
patient population.
Keywords
cholangiocarcinoma - radiation therapy - stereotactic body radiation therapy - biliary
tract cancer
