The impact of beam angle configuration of intensity-modulated radiotherapy in the hepatocellular carcinoma

Abstract

PurposeThis treatment planning study was undertaken to evaluate the impact of beam angle configuration of intensity-modulated radiotherapy (IMRT) on the dose of the normal liver in hepatocellular carcinoma (HCC).Materials and MethodsThe computed tomography datasets of 25 patients treated with IMRT for HCC were selected. Two IMRT plans using five beams were made in each patient; beams with equidistance of 72° (Plan I), and beams with a 30° angle of separation entering the body near the tumor (Plan II). Both plans were generated using the same constraints in each patient. Conformity index (CI), homogeneity index (HI), gamma index, mean dose of the normal liver (Dmean_NL), Dmean_NL difference between the two plans, and percentage normal liver volumes receiving at least 10, 20, and 30 Gy (V10, V20, and V30) were evaluated and compared.ResultsDmean_NL, V10, and V20 were significantly better for Plan II. The Dmean_NL was significantly lower for peripheral (p = 0.001) and central tumors (p = 0.034). Dmean_NL differences between the two plans increased in proportion to gross tumor volume to normal liver volume ratios (p = 0.002). CI, HI, and gamma indices were not significantly different for the two plans.ConclusionThe IMRT plan based on beams with narrow separations reduced the irradiated dose of the normal liver, which would allow radiation dose escalation for HCC.

Loss of EGF‐dependent cell proliferation ability on radioresistant cell HepG2‐8960‐R

“…In recent years, many guidelines for the management of HCC have been published throughout the world. [19][20][21] Surgical resection of HCC is the treatment of choice, while a treatment option for unresectable HCC involves RT alone or in combination with other therapies. 18 RT is a major treatment for many types of cancer.…”

“…Increasing evidence indicates that current RT technology, including intensity-modulated RT, image-guided RT and helical tomotherapy may be effective against HCC as well as prostate cancer and neck and head cancer. [19][20][21] Surgical resection of HCC is the treatment of choice, while a treatment option for unresectable HCC involves RT alone or in combination with other therapies. 18 The current RT technology with the accurate spatial and temporal variation of irradiation allows a higher dose of radiation than the conventional dose without affecting normal tissues.…”

Dosimetric comparison of volumetric modulated arc therapy with robotic stereotactic radiation therapy in hepatocellular carcinoma

“…Therefore, several alternative modalities of surgery such as transarterial chemoembolization, percutaneous ethanol injection, radiofrequency ablation, sorafenib, or radiotherapy (RT) have been used [ 2 3 4 5 6 7 ]. Although recent advances in RT techniques including intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic body radiation therapy (SBRT) have augmented the role of RT in HCC [ 6 7 8 9 10 11 12 ], in the past, RT had a limited role because of the high risk of liver toxicities such as radiation-induced liver disease (RILD), which is believed to be an almost fatal complication once it occurs [ 13 14 15 ].…”

Knowledge‐based intensity‐modulated radiotherapy plans for cervical cancer with overlap volume of target and organs at risk

“…Sung et al. found that the exposure dose to normal liver tissue of IMRT plans for five adjacent uneven fields was less than that of IMRT plans for five equational fields surrounding the target . Therefore, K‐IMRT should be used for the optimization of IMRT plans, and the field angle should be set manually by the radiotherapy physicist, according to the four basic principles of field angle and treatment experience.…”

“…[16][17][18] Sung et al found that the exposure dose to normal liver tissue of IMRT plans for five adjacent uneven fields was less than that of IMRT plans for five equational fields surrounding the target. 19 Therefore, K-IMRT should be used for the optimization of IMRT plans, and the field angle should be set manually In conclusion, K-IMRT is an application of big data. It can be trained using the radiotherapy plans of therapeutic patients and then used to optimize the radiotherapy plans of new patients.…”