Table 4Local radiotherapies for primary hepatocellular carcinoma reviewed in this report*

Treatment StrategyMechanism of Cell DeathSettingPerformed BySpecific Harms
External-beam three-dimensional conformal radiation therapy (3D-CRT)This type of radiotherapy uses computer-assisted tomography (CT or CAT) and/or magnetic resonance imaging (MR or MRI), or both to create detailed, 3D representations of the tumor and the surrounding organs. The radiation oncologist uses these computer-generated images to shape radiation beams to the exact size and shape of the tumor, which is intended to spare nearby healthy tissues.Each treatment lasts only a few minutes, although the setup time usually takes longer. Most often, radiation treatments are given 5 days a week for several weeks. The patient's diagnosis determines the total duration of treatment.31,32Radiation oncologist, medical physicist, dosimetrist, radiation therapist, and radiation therapy nursePossible side effects of external radiation therapy include: sunburn-like skin problems, nausea, vomiting, and fatigue. These typically diminish posttreatment. Radiation might also make the side effects of chemotherapy worse.25 Radiation-induced liver disease is the major dose limiting toxicity.23
External-beam intensity-modulated radiotherapy (IMRT)This approach to radiotherapy allows the radiation oncologist to vary both the intensity of a radiation beam and the angle at which it is delivered to the patient. This is intended to deliver a high dose of radiation to a tumor while significantly reducing the dose to surrounding normal tissue. IMRT offers a better defined radiation dose over traditional 3D-CRT.Same as 3D-CRT, but IMRT requires slightly longer daily treatment times and additional planning and safety checks before the patient can start the treatment.33Radiation oncologist, medical physicist, dosimetrist, radiation therapist, and radiation therapy nurseSame as for 3D-CRT.
Stereotactic body radiation therapy (SBRT)This type of external-beam radiation therapy delivers a high dose of radiation with high targeting accuracy to an extracranial target within the body in either a single dose or a small number of dose fractions.34SBRT typically consists of one to five treatment sessions over the course of 1 to 2 weeks.35Radiation oncologist, medical physicist, dosimetrist, radiation therapist, and radiation therapy nurseSame as above for 3D-CRT and IMRT.
Hypofractionated proton beam therapyThis is a type of external-beam radiation therapy that delivers high doses of radiation to the tumor target while simultaneously reducing the number of photons reaching normal surrounding tissue, delivered in fewer sessions of larger dose fractions than are delivered in standard regimens.34Proton beam therapy is performed typically on an outpatient basis. For most tumor sites, the average course of treatment is usually 5 to 7 weeks, with varying length of each treatment depending on the tumor type and stage. The delivery of the proton beam lasts only 1 minute.35Radiation oncologist, radiation physicist, dosimetrist, immobilization specialist, radiation therapy nurseSame as above for 3D-CRT, IMRT, and SBRT.
Intraluminal brachytherapyThis type of radiotherapy places a radiation source within the body, allowing the delivery of higher doses of radiation directly to a specific tumor.20-22 Brachytherapy can be administered as a permanent or temporary treatment.In permanent brachytherapy, a radioactive “seed” is permanently implanted in the tumor. Seeds may also be implanted at regular intervals. In temporary brachytherapy, treatments may be delivered at a high dose-rate (HDR) in 10 to 20 minutes per session or at a low dose-rate (LDR) in 20 to 50 hours. HDR brachytherapy is usually an outpatient procedure in which the treatment is repeated two times a day for up to 10 separate treatments in 1 or more weeks. LDR brachytherapy, an inpatient procedure, delivers radiation at a continuous rate in 1 to 2 days. Pulsed dose-rate (PDR) brachytherapy delivers radiation in periodic pulses (usually 1 per hour) rather than continuously.36Radiation oncologist, medical physicist, dosimetrist, radiation therapist, radiation therapy nurse, and in some cases, a surgeonBrachytherapy typically causes fewer side effects than does external-beam radiation.37 39Patients may experience tenderness and swelling in the treatment area and other symptoms depending on the site of brachytherapy and can resume normal activities within days or weeks of brachytherapy.

The radiotherapy presented in this report is focused on focal treatment of the lesion or lesions and not whole liver irradiation.

From: Introduction

Cover of Local Therapies for Unresectable Primary Hepatocellular Carcinoma
Local Therapies for Unresectable Primary Hepatocellular Carcinoma [Internet].
Comparative Effectiveness Reviews, No. 114.
Belinson S, Yang Y, Chopra R, et al.

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