Prospective nonrandomized comparison of two modes of argon beamer (APC) tumor desobstruction: effectiveness of the new pulsed APC versus forced APC.
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). 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 effect were: amount of lumen restoration ((1/3), (2/3), complete), objective planimetry, stenosis length, treatment time, and number of APC sessions. 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. 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.