PURPOSE: The purpose of this study was to investigate the safety and efficacy of proton beam therapy (PBT) for the treatment of metastatic liver tumors. MATERIAL AND METHODS: A total of 140 patients with liver metastasis who received PBT were retrospectively investigated. The main primary tumor sites were the colorectum (60) and the pancreas (19). RESULTS: One hundred thirty-three patients (95%) completed treatment. Two patients experienced late adverse effects (rib fracture and cholangitis). The 5-year overall survival (OS) rate was 24%. In the 85 patients with lesions confined to the liver, the 5-year OS rate of was 28%, and in the 55 patients with lesions both inside and outside the liver, it was 16% (P=0.007). Among the patients with lesions confined to the liver, the 5-year OS rate of the 62 patients who received curative treatment was 30%, and that of the 23 patients who received palliative treatment, 23% (P=0.016). Multivariate analysis showed that the treatment strategy (curative and palliative) alone was associated with the OS rate (P=0.02). CONCLUSION: PBT is a potentially safe and effective treatment for metastatic liver tumors.
PURPOSE: The purpose of this study was to investigate the safety and efficacy of proton beam therapy (PBT) for the treatment of metastatic liver tumors. MATERIAL AND METHODS: A total of 140 patients with liver metastasis who received PBT were retrospectively investigated. The main primary tumor sites were the colorectum (60) and the pancreas (19). RESULTS: One hundred thirty-three patients (95%) completed treatment. Two patients experienced late adverse effects (rib fracture and cholangitis). The 5-year overall survival (OS) rate was 24%. In the 85 patients with lesions confined to the liver, the 5-year OS rate of was 28%, and in the 55 patients with lesions both inside and outside the liver, it was 16% (P=0.007). Among the patients with lesions confined to the liver, the 5-year OS rate of the 62 patients who received curative treatment was 30%, and that of the 23 patients who received palliative treatment, 23% (P=0.016). Multivariate analysis showed that the treatment strategy (curative and palliative) alone was associated with the OS rate (P=0.02). CONCLUSION: PBT is a potentially safe and effective treatment for metastatic liver tumors.