Solutions that enable ablative radiotherapy for large liver tumors: Fractionated dose painting, simultaneous integrated protection, motion management, and computed tomography image guidance

Abstract

The emergence and success of stereotactic body radiation therapy (SBRT) in lung cancer has led to its rapid adoption for liver cancers. SBRT can achieve excellent results for small liver tumors. However, the vast majority of physicians interpret SBRT as meaning doses of radiation (4 to 20 Gy) that may not be ablative, but are delivered within about 1 week (i.e., in 3 to 6 fractions). Adherence to this approach has limited the effectiveness of SBRT for large liver tumors (> 7 cm) owing to the need to reduce doses to meet organ constraints. The prognosis for patients who present with large liver tumors is poor with median survival times of 12 months or less, and most such patients die from tumor-related liver failure. Herein, we present a comprehensive solution to achieve stereotactic ablative body radiation (SABR) doses for patients with large liver tumors by using a combination of classical, modern, and novel concepts of radiotherapy: fractionation, dose painting, motion management, image guidance, and simultaneous integrated protection. We discuss these concepts in the context of large inoperable liver tumors and review how this approach can substantially prolong survival for patients, most of whom otherwise have a very poor prognosis and few effective treatment options.

Significant symptoms alleviation and tumor volume reduction after combined simultaneously integrated inner-escalated boost and volumetric-modulated arc radiotherapy in a patient with unresectable bulky hepatocellular carcinoma

“…[53] In the present case, we used a similar modified SIB by incorporating VMAT, i.e., SIEB-VMAT. When compared with the published modified-SIB, [50–52] a similar point was that a larger fraction size is delivered to the geometrically central region of a bulky tumor (in the same treatment fractions), intending to gain a better tumor control.…”

Local therapy reduces the risk of liver failure and improves survival in patients with intrahepatic cholangiocarcinoma: A comprehensive analysis of 362 consecutive patients

“…11 Since 2010, radiation was more frequently delivered using a simultaneous integrated boost (doses of 60-75 Gy in 15 fractions or 75-100 Gy in 25 fractions) with simultaneous integrated protection of the adjacent organs, achieving biologic equivalent doses above 80.5 Gy. 23 Systemic chemotherapy continues to vary; most regimens prior to 2000 contained 5-fluorouracil and leucovorin, and newer regimens often contained gemcitabine and other non-5-fluorouracil-based compounds. 13, 14, 20, 24 Patients who were medically unfit for or refused the treatments described above received best supportive care.…”

Cholangiocarcinoma — evolving concepts and therapeutic strategies

“…Technological advances have improved the safety and effectiveness of radiation therapy for cholangiocarcinoma 75 . High-resolution, multiphase helical CT and multiparametric MRI of the liver and biliary tree have enabled more-precise determination of cancer location and the extent of radiotherapy targeting.…”