Irradiation in carcinoma of the vulva: factors affecting outcome

This report reviews the increasing role of radiation therapy in the management of patients with histologically confirmed vulvar carcinoma, based on a retrospective analysis of 68 patients with primary disease (2 in situ and 66 invasive) and 18 patients with recurrent tumor treated with irradiation alone or combined with surgery.

Of the patients with primary tumors, 14 were treated with wide local excision plus irradiation, 19 received irradiation alone after biopsy, 24 were treated with radical vulvectomy followed by irradiation to the operative fields and inguinal-femoral/pelvic lymph nodes, and 11 received postoperative irradiation after partial or simple vulvectomy. The 18 patients with recurrent tumors were treated with irradiation alone. Indications and techniques of irradiation are discussed in detail.

In patients treated with biopsy/local excision and irradiation, local tumor control was 92% to 100% in Stages T1-3N0, 40% in similar stages with N1-3, and 27% in recurrent tumors. In patients treated with partial/radical vulvectomy and irradiation, primary tumor control was 90% in patients with T1-3 tumors and any nodal stage, 33% in patients with any T stage and N3 lymph nodes, and 66% with recurrent tumors. The actuarial 5-year disease-free survival rates were 87% for T1N0, 62% for T2-3N0, 30% for T1-3N1 disease, and 11 % for patients with recurrent tumors; there were no long-term survivors with T4 or N2-3 tumors. Four of 18 patients (22%) treated for postvulvectomy recurrent disease remain disease-free after local tumor excision and irradiation. In patients with T1-2 tumors treated with biopsy/wide tumor excision and irradiation with doses under 50 Gy, local tumor control was 75% (3 of 4), in contrast to 100% (13 of 13) with 50.1 to 65 Gy. In patients with T3-4 tumors treated with local wide excision and irradiation, tumor control was 0% with doses below 50 Gy (3 patients) and 63% (7 of 11) with 50.1 to 65 Gy. In patients with T1-2 tumors treated with partial/radical vulvectomy and irradiation, local tumor control was 83% (14 of 17), regardless of dose level, and in T3-4 tumors, it was 62% (5 of 8) with 50 to 60 Gy and 80% (8 of 10) with doses higher than 60 Gy. The differences are not statistically significant. There was no significant dose response for tumor control in the inguinal-femoral lymph nodes; doses of 50 Gy were adequate for elective treatment of nonpalpable lymph nodes, and 60 to 70 Gy controlled tumor growth in 75% to 80% of patients with N2-3 nodes when administered postoperatively after partial or radical lymph node dissection. Significant treatment morbidity included one rectovaginal fistula, one case of proctitis, one rectal stricture, four bone/skin necroses, four vaginal necroses, and one groin abscess.

Irradiation is playing a greater role in the management of patients with carcinoma of the vulva; combined with wide local tumor excision or used alone in T1-2 tumors, it is an alternative treatment to radical vulvectomy, with significantly less morbidity. Postradical vulvectomy irradiation in locally advanced tumors improves tumor control at the primary site and the regional lymphatics in comparison with reports of surgery alone.