Intensity Modulated Proton Therapy with Advanced Planning Techniques in a Challenging Hepatocellular Carcinoma Patient

Abstract

The use of radiation therapy has been increasing over recent years for the treatment of hepatocellular carcinoma (HCC). Proton beam therapy (PBT) has emerged as a promising treatment option for HCC patients due to its dosimetric advantages of sparing more normal liver tissue from radiation at low to moderate doses compared to photon-based treatments while still delivering high doses of radiation to tumors. The PBT therapy may be particularly beneficial in high-risk HCC cirrhotic patients with large, bulky tumors and/or vascular invasion complicated by surrounding perfusion abnormalities. We present a case of a 62-year-old male with an unresectable 13 cm diffusely infiltrative HCC tumor with main portal vein invasion and elevated alpha-feta protein (AFP) of 37,200 that was intolerant of standard sorafenib treatment. He was treated with hypofractionated PBT to 67.5 GyE in 15 fractions using a novel combination of simultaneously integrated boost intensity modulated proton therapy (SIB-IMPT), breath hold technique, and functional liver imaging with technetium-99m [99mTc] sulfur colloid single-photon emission computed tomography (SPECT/CT) to assist in the differentiation of tumor and normal liver. He had a complete radiographic and biochemical response by AFP normalization by seven months post-treatment without evidence of radiation hepatotoxicity.

Radiation-Induced Liver Disease and Modern Radiotherapy

“…The University of Washington group has also published a number of planning studies looking at avoidance of high functioning liver using both proton and VMAT photon plans. 58, 59 Most recently, they have published a series on 87 patients treated with liver SBRT using functional optimization with 99m Tc-sulfur colloid SPECT-CT in which no grade 3 and above toxicity was seen while maintaining excellent local control. 51 Building on these promising results, they currently have a trial open evaluating the role of SPECT-CT for radiation therapy and surgical planning for primary and metastatic liver cancers (NCT02881554).…”

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

“…Utilizing PBS-IMPT, a simultaneous integrated boost (SIB) and protection (SIP) technique may be more feasible than with photon-based IMRT and allow for dose escalation to the part of the tumor with lower-dose levels near critical OARs. 78 , 88 Kim et al reported results of a PBT-IMPT SIB approach in patients with advanced HCC with tumor vascular thrombosis (TVT): 2-yr local progression-free survival of 88%, OS of 51%, and no grade ≥3 toxicity. 78 Higher biologic equivalent dose was associated with better TVT response, which was an independent prognostic factor for improved OS.…”

Dosimetric comparison of proton therapy and CyberKnife in stereotactic body radiation therapy for liver cancers

“…This is equivalent to the use of respiratory gating/breath hold for PBT. However, the nature of PBT using pencil beam scanning techniques could require a significant number of breath holds which may be difficult for patients to comply as discussed by Apisarnthanarax et al (2017) [20]. Therefore, it may be more practical for some patients to be treated under free breathing conditions, so that the PBT is planned using the ITV.…”