Options for radiotherapy in the treatment of liver metastases

Patterns of prescribing radiotherapy and bevacizumab in nationwide practice - analysis of 101 designated cancer care hospitals in Japan

Radiotherapy and bevacizumab are each effective in treating patients with advanced cancer, but their concurrent use may cause serious adverse events (SAEs). Whereas sequential administration can theoretically reduce the risk of SAEs while maintaining the anticancer effects, this hypothesis remains unconfirmed, leading to variations in practice. To elucidate current practices, the patterns of care received by patients in Japan with regard to these two therapies were assessed in a large database of a hospital-based cancer registry linked with insurance claims. This database contained information on 106 057 patients diagnosed with seven major cancers in 2011 and the care they received up to the end of 2012. In total, 335 patients from 101 hospitals in the database were treated with both radiotherapy and bevacizumab. Of these patients, 50.8% had lung cancer, and 51.3% had Stage IV cancer. Of the 335 patients, 75 (22.4%) received these therapies concurrently. In patients treated sequentially, the time from the last dose of bevacizumab to the start of radiotherapy was most frequently 4-5 weeks (12.4%), whereas the time from the end of radiotherapy to the start of bevacizumab was most frequently 1-2 weeks (10.6%). The cumulative proportions of patients in these two groups receiving sequential therapies within 3 weeks were 19.0% and 26.1%, respectively. Many practices appeared to avoid the concurrent use of bevacizumab and radiation, but some provided concurrent therapy. Additional data are required to determine whether the avoidance of concurrent use should become a standard of care.

125I radioactive seed interstitial brachytherapy for liver metastases

AIM: To detect the efficacy of ¹²⁵I radioactive seed interstitial brachytherapy for liver metastases.

METHODS: Thirty-two tumors in 24 patients with liver metastases were treated by ¹²⁵I radioactivity seed interstitial brachytherapy. The tumor diameter ranged from 4.5 to 12.8 cm, with an average value of 7.8 cm. The treatment response, local control rate and survival rate were evaluated and adverse events observed.

RESULTS: Complete remission (CR) was achieved in 7 tumors, and partial remission (PR) was achieved in 16 tumors. Five tumors had no remission (NR), and 4 tumors had progressive deterioration (PD). The response rate was 71.9%. The patients were followed up for 7 to 22months (median 16 mo). The local control rate was 65.9%, and total survival rate 70.1%. No serious side effects were observed.

CONCLUSION: Radioactive seed interstitial brachytherapy is an effective form of treatment for patients with liver metastases.

Interstitial implantation of iodine-125 seeds induces apoptosis but inhibits cell proliferation in HCT-116-xenografted tumors in nude mice

AIM: To investigate the effect of interstitial implantation of iodine-125 on the growth of adenocarcinoma of the large intestine and to explore potential mechanisms involved.

METHODS: Nude mice bearing HCT-116-xenografted tumors were randomly divided into two groups (n = 24 each): control group and experimental group. The control group underwent implantation of empty seeds, while the experiment group underwent implantation of iodine-125 seeds (14.8 MBq). On days 7, 14, 21 and 28 after implantation, mice were killed to calculate tumor growth, detect the expression of proliferating cell nuclear antigen (PCNA) in tumor tissue by immunohistochemistry, determine the apoptosis of tumor cells by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, and observe the ultrastructural changes of tumor cells by transmission electron microscopy (TEM).

RESULTS: On days 7, 14, 21 and 28 after implantation, both tumor volume and weight were significantly lower in the experiment group than in the control group (tumor volume on day 28: 497.3 mm3 ± 7.8 mm3 vs 947.2 mm3 ± 40.4 mm3, P < 0.01; tumor weight on day 28: 1.131 g ± 0.079 g vs 2.139 g ± 0.094 g, P < 0.01). The reduced rate of tumor growth in the experimental group was higher than that in the control group (on day 28: 47.12% vs 25.77%). The expression of PCNA in the experiment group decreased with time and was significantly lower on day 28 than that in the control group. On day 14, apoptotic bodies began to appear and then gradually increased in number, reaching the peak on day 28.

CONCLUSION: Interstitial implantation of iodine-125 seeds induces apoptosis but inhibits cell proliferation in HCT-116-xenografted tumors in nude mice.

Advances in permanent 125I seed implantation for colorectal liver metastases

Colorectal cancer is one of the most common cancers worldwide and the second most common type of cancer in the Western world. Colorectal cancer is the most common source of metastatic liver cancer, and liver metastasis is an important prognostic factor for colorectal cancer. Hepatic resection is the treatment of choice for colorectal liver metastases. The postoperative 5-year survival rate for patients with colorectal liver metastase now exceeds 50%. However, hepatic resection is indicated for only 10%-25% of patients with colorectal liver metastases. Therefore, non-surgical methods have attracted increasing attention. Permanent ¹²⁵I seed implantation is now becoming a hotspot for treatment of colorectal liver metastases. This review will focus on the recent advances in permanent ¹²⁵I seed implantation for colorectal liver metastases.