Clinical Study of 2 Radiotherapy Techniques for Semi-Hepatic Alternating Radiotherapy on Diffuse Liver Metastasis in Patients with Breast Cancer

Objective: To compare the effects of 2 techniques of semi-hepatic alternating radiotherapy on diffuse hepatic metastasis in patients with breast cancer. Methodology: A total of 68 breast cancer patients with diffuse liver metastasis were randomly divided into Group A (semi-hepatic alternating radiotherapy) and Group B (semi-hepatic sequential radiotherapy). In Group A (semi-hepatic sequential radiotherapy), the liver was divided into the first semi-liver and second semi-liver and alternatively treated with semi-hepatic intensity-modulated radiation therapy (IMRT). The interval between the 2 instances of semi-hepatic radiotherapy was 6 h. The average radiotherapy dose to the semi-livers was both 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The total radiation therapy time in Group A was 15 days in Group B (semi-hepatic sequential radiotherapy), the livers were divided into the first semi-liver and second semi-liver and treated with semi-hepatic sequential IMRT, The first semi-liver was first treated in the initial stage of radiation therapy, the average radiotherapy dose to the semi-liver was 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The second semi-liver was treated next in the second stage of radiation therapy, the average radiotherapy dose to the semi-liver was 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The total radiation therapy time in group B was 30 days. Results: The objective response rate (complete response + partial response) of Group A and Group B were 50.0% and 48.5%, respectively (p = .903). The median survival time after metastasis (median survival of recurrence) of Group A and Group B was 16.7 months and 16.2 months, respectively (p = .411). The cumulative survival rates of 6 months, 1 year, 2 years, and 3 years of Group A and Group B were 90.6% (29 of 32) and 84.8% (28 of 33) (p = .478), 65.6% (21 of 32) and 60.6% (20 of 33) (p = .675), 31.2% (10 of 32) and 27.3% (9 of 33) (p = .725), and 15.6% (5 of 32) and 0 (0 of 33) (p = .018), respectively. The differences between the 2 groups showed no statistical significance in terms of cumulative survival rates in 1 year, 2 years, however, the 3-year survival rate was significantly different. The main toxic reactions were digestive tract reactions, abnormal liver functions, and myelosuppression. The incidence of I to II degree gastrointestinal reactions was 78.13% (25 of 32) in Group A and 72.73% (24 of 33) in Group B (p = .614). The incidence of I to II abnormal liver function was 53.13% (17 of 32) in Group A and 48.48% (16 of 33) in Group B (p = .708). The differences between the 2 groups showed no statistical significance. The incidence of I to II myelosuppression was 59.38% (19 of 32) in Group A and 51.52% (17 of 33) in Group B (p = .524), respectively. The differences between the 2 groups showed no statistical significance in terms of adverse effects. Conclusion: Semi-hepatic alternating IMRT was an effective palliative treatment for diffuse liver metastasis in patients with breast cancer. Semi-hepatic alternating radiotherapy showed a trend of prolonged survival time when compared with semi-hepatic sequential radiotherapy. Compared with the former, the latter showed a trend of lower incidences of side effects without any statistical differences. Moreover, the side effects from the 2 radiotherapy techniques can be controlled through appropriate management, which is worthy of further exploration and applications.