PURPOSE:The aim of this study was to assess the efficacy of radiofrequency ablation in the treatment of pelvic recurrent rectal cancer.METHODS:Computed tomography‐guided percutaneous radiofrequency ablation was performed by placing a LeVeen needle electrode into the tumor. Radiofrequency ablation was performed on three lesions in two patients with pelvic recurrent rectal cancer, where the tumors were unresectable and associated with poorly controllable pain despite local treatment consisting of chemoradiotherapy.RESULTS:There were no major complications during the radiofrequency ablation procedure, although one patient complained of a sensation of warmth in the pelvic region, which was reasonably tolerated.Case 1: Each of two lesions of pelvic recurrence, 3 or 4 cm in diameter, was treated once by radiofrequency ablation with placement of a needle electrode into the tumor mass. After the procedure, magnetic resonance imaging confirmed nearly complete necrosis of the tumors, and there was a sufficient relief of pain enabling discontinuation of an opioid. Serum carcinoembryonic antigen returned to normal and there was no evidence of relapse six months after the treatment.Case 2: Radiofrequency ablation was performed by placing a needle electrode at two sites of a recurrent tumor 6 cm in diameter. Postradiofrequency ablation imaging showed viable tissue remnants along the tumor margin, but the treatment produced relief of pain. The procedure was effective in opioid dosage reduction and pain control within a limited time span.CONCLUSION:Radiofrequency ablation is a relatively readily maneuverable and safe local treatment for pelvic recurrence in rectal cancer and is considered a procedure worth applying with further accumulation of experience in clinical cases.