Intensity-modulated radiotherapy for the treatment of vulvar carcinoma: a comparative dosimetric study with early clinical outcome.

Objectives: To assess early clinical outcome of intensity-modulated radiation therapy (IMRT) in the treatment of vulvar cancer and compare dosimetric parameters with 3D conformal radiotherapy (3D CRT).

Methods: Fifteen patients with vulvar cancer were treated with IMRT. Seven patients were treated with preoperative chemoradiation, and 8 patients were treated with adjuvant postoperative radiation therapy. Median dose was 46 Gy in the preoperative and 50.4 Gy in the postoperative group.

Results: The mean volume of small bowel, rectum, and bladder that received doses in excess of 30 Gy with IMRT was reduced when compared with 3D CRT. Treatment was well tolerated, and only 1 patient had acute Grade 3 small-bowel toxicity. Median follow-up was 12 months. In the preoperative group, 5 patients (71%) had clinical complete response and 3 patients (42.8%) had pathologic complete response. In the adjuvant group, 2 patients had recurrences in the treatment field. No patients had late Grade 3 toxicity. The 2-year actuarial disease-specific survival was 100%.

Conclusions: Intensity-modulated RT appears to offer advantages over 3D CRT treatment of vulvar cancer by elimination of dose modulation across overlapping regions and reduction of unnecessary dose to the bladder, rectum, and small bowel. Early results with a small number of patients show promising results, with a low incidence of severe toxicity.