Prospective nonrandomized comparison of two modes of argon beamer (APC) tumor desobstruction: effectiveness of the new pulsed APC versus forced APC

Background and study aim: Argon plasma coagulation (APC) has become an established noncontact method of tumor palliation in a variety of locations. The present prospective study evaluated a new APC system (APC-2) using amplified power settings and different application modes, such as intermittent energy delivery (pulsed APC) in comparison with the conventional technique (forced APC). Patients and methods: A total of 100 patients with esophageal, gastric, or rectal tumors were alternately (but not randomized) enrolled and treated with either pulsed APC (n = 46) or forced APC (n = 54). Parameters to assess the palliative 2 effect were: amount of lumen restoration (1/3, /3, complete), objective planimetry, stenosis length, treatment time, and number of APC sessions. Results: Overall response rate was similar in both groups (pulsed 83 %, forced 87 %), the same was found in the subgroups with different amounts of lumen restoration and for the other objective parameters. However, the tumor debulking effect was achieved in a significantly shorter median treatment time with forced compared with pulsed APC (13.6 vs. 18.2 minutes, P= 0.03), with a similar number of treatment sessions in both groups. Complications also occurred with similar frequency in both groups. Conclusions: There was no significant difference in overall local tumor response between the two modes of APC application. However, data from this nonrandomized study suggest a faster achievement of response with forced APC. A combination of both modes may be superior.