Vacuum-assisted resection of malignant tumors with and without subsequent radiofrequency ablation: Feasibility of complete tumor treatment tested in an animal model

Purpose: To evaluate the feasibility of vacuum-assisted tumor excision with and without RF ablation for the minimally invasive treatment of small tumo rs. Materials and methods: Twenty VX2 tumors were implanted bilaterally into th e spine muscle of 10 rabbits. Tumor excision was performed after tumor size s reached 10 mm (12-27 d incubation) with use of a vacuum-assisted biopsy d evice. Three or four directed vacuum-assisted biopsies were performed in an gle steps of 30 degrees. In 10 tumors, ultrasound (US)-guided radiofrequenc y (RF) ablation (8 min, 60 W) was subsequently performed with use of a cool ed-tip electrode system. Follow-up US was performed at 3-4-day intervals fo r as long as 3 weeks after excision/RF ablation. Autopsy and histopathologi c analysis were performed. Results: The duration of vacuum excision ranged from 12 to 45 minutes (25 m in +/- 7). Histologically tumor-free margins in the outer round of the core biopsy specimens were found in only four of 20 cases (20%). Maximum lesion sizes during RF ablation ranged from 18 to 25 mm (20 mm +/- 2.6). Histolog ic examination of the excision specimens documented tumor-free margins in o nly three tumors (30%) among the excision-only group and only one (10%) amo ng the combined excision/ablation group. Local recurrences occurred in eigh t of 10 cases (80%) after vacuum excision alone, whereas recurrence after c ombined excision and RF ablation occurred only in two of 10 cases (20%; P<. 05). Conclusions: Local tumor resection with use of vacuum-assisted biopsy is fe asible and promising as a minimally invasive therapy for the treatment of s mall focal breast neoplasms. Combined excision and RF ablation techniques m ay reduce the rate of local recurrence considerably.