Tumor recurrence rates after cryotherapy range from 12% to 24%, and they can be even higher for larger tumors or those located near the trachea or vessels, which limit the ability of cryotherapy probes to cool the region. But the researchers from China are slashing those recurrence rates by implanting iodine-125 brachytherapy seeds concurrently with the cryotherapy procedures.
Wei Tao Dou, MD, and colleagues from Shandong University ablated 80 lung cancer tumors (54 patients; mean age, 57.6 years) with cryotherapy and iodine-125 seeds on the periphery of the tumor during the two-year course of the study. The tumors ranged in size from 2 to 8 cm (mean, 4.6 cm). Single or multiple 17-mm cryoprobes were used for ablation of the central zone, and seeds were implanted along the edge of the ablation region, the authors noted.
At follow-up of three to 19 months, the researchers examined the results based on tumor size, changes in tumor markers, and disease recurrence. They found tumor markers reduced, tumor sizes reduced, and targeted tumor recurrence at one, three, and six months of 0% (0/80), 4% (3/80), and 6% (5/80), respectively -- much lower than previous reports without the use of iodine-125. Four cases of symptomatic pneumothorax were detected postprocedurally at CT.
Cryotherapy plus brachytherapy is safe and offers lower recurrence rates than cryotherapy alone, the group concluded.