Objective Hypofractionated radiotherapy has recently been applied to treat pulmonary metastases of hepatocellular carcinoma. However, there is no definite evidence on its safety and efficacy. We evaluate the clinical outcomes of hypofractionated radiotherapy for oligo pulmonary metastases of hepatocellular carcinoma in the multicenter and retrospective study. Methods From March 2011 to February 2018, 58 patients with fewer than five pulmonary metastases of hepatocellular carcinoma who underwent hypofractionated radiotherapy in nine tertiary university hospitals were analyzed retrospectively. The primary endpoint was the local control rate. The secondary endpoints were overall survival, progression-free survival, prognostic factors affecting the treatment outcomes and treatment-related side effects. Results The local tumor response rate including complete and partial response was 77.6% at 3 months after hypofractionated radiotherapy. The median survival and progression-free survival times were 20.9 and 5.3 months, respectively. The 1-year overall survival and progression-free survival rates were 65.5 and 22.4%, respectively. The good treatment response after hypofractionated radiotherapy (P = 0.001), the absence of intrahepatic tumor (P = 0.004) and Child-Pugh class A (P = 0.010) were revealed as significant prognostic factors for overall survival in the multivariate analysis. A progression-free interval of <6 months (P = 0.009) was a negative prognostic factor for overall survival in the multivariate analysis. Of 58 patients, five (8.6%) had grade 2 or higher radiation pneumonitis after hypofractionated radiotherapy. Conclusions The favorable local control rate and acceptable toxicity indicate the clinical usefulness of hypofractionated radiotherapy for hepatocellular carcinoma patients who have less than five pulmonary metastases.

Radiotherapy techniques for breast cancer have evolved with efforts to reduce treatment-related side effects. In the present study, we conducted dosimetric analysis of incidental axillary irradiation between volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT). A total of 20 patients with early stage left breast cancer who underwent breast-conserving surgery followed by postoperative radiotherapy were analyzed. For VMAT plans, dose-volume constraints were not imposed on the axilla, as with 3D-CRT. We compared the dosimetric parameters of the planning target volumes, organs at risk and axillary level I-III of the two plans. VMAT showed better target coverage and a normal organ-sparing effect compared with 3D-CRT. The incidental axillary irradiation of VMAT was lower; the mean dose and the V40 Gy were significantly reduced at all axillary levels, with the exception of no difference in the maximum dose to axillary level I. In conclusion, VMAT decreased incidental axillary irradiation, even in the absence of a dose-volume constraint on the axilla, and can, therefore, decrease the risk of radiotherapy-related lymphedema. However, caution is also required because it is unclear whether this incidental axillary irradiation is beneficial for reducing recurrence on the axilla.