Consensus Recommendations for Radiation Therapy Contouring and Treatment of Vulvar Carcinoma

Abstract

Purpose The purpose of this study was to develop a radiation therapy (RT) contouring atlas and recommendations for women with postoperative and locally advanced vulvar carcinoma. Methods and Materials An international committee of 35 expert gynecologic radiation oncologists completed a survey of the treatment of vulvar carcinoma. An initial set of recommendations for contouring was discussed and generated by consensus. Two cases, 1 locally advanced and 1 postoperative, were contoured by 14 physicians. Contours were compared and analyzed using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE), and a 95% confidence interval contour was developed. The level of agreement among contours was assessed using a kappa statistic. STAPLE contours underwent full committee editing to generate the final atlas consensus contours. Results Analysis of the 14 contours showed substantial agreement, with kappa statistics of 0.69 and 0.64 for cases 1 and 2, respectively. There was high specificity for both cases (≥99%) and only moderate sensitivity of 71.3% and 64.9% for cases 1 and 2, respectively. Expert review and discussion generated consensus recommendations for contouring target volumes and treatment for postoperative and locally advanced vulvar cancer. Conclusions These consensus recommendations for contouring and treatment of vulvar cancer identified areas of complexity and controversy. Given the lack of clinical research evidence in vulvar cancer radiation therapy, the committee advocates a conservative and consistent approach using standardized recommendations.

Patterns of treatment failure in patients undergoing adjuvant or definitive radiotherapy for vulvar cancer

“…As nearly all recurrences were in-field, the issue does not appear to be delineation misses, that is, tight contouring margins. As our delineations should match the published consensus recommendations for contouring,8 the observed recurrence pattern thus indirectly supports these recommendations. These results indicate that local intensification of treatment, if possible, appears an attractive research avenue for patients with high-risk disease; however, whether a radiation dose response is present in vulvar cancer has not, to our knowledge, been tested.…”

Intensity modulated radiation therapy for squamous cell carcinoma of the vulva: Treatment technique and outcomes

“…However, because our study has a small number of patients with limited follow-up, additional data are needed on whether treatment volumes can be reduced with FDG-PET/CT imaging. We acknowledge that the recently published consensus guidelines, which recommend including the entire inguinal compartment in the CTV, are the most conservative approach to ensure coverage of the inguinal nodal region 11 . The dose to the sites of inguinal recurrences in our study were 5040 cGy in a patient with a resected 3-cm lymph node with extracapsular extension and 6000 cGy in a patient with a previously unresected 4-cm lymph node.…”

Cancer of the vulva

“…3D conformal/Anterior–Posterior/Posterior–Anterior [AP/PA] fields, intensity‐modulated radiation therapy [IMRT]). To ensure adequate tumor coverage, clinical examination, imaging findings (CT or MRI), and nodal size should be considered to properly define the target volume during 3D planning …”

“…However, if histology reveals positive nodes, then adjuvant radiation to the groin and pelvis should be offered as for early stage disease. 61 In cases where surgery is thought to be inappropriate for the individual patient, primary chemoradiation may be used to treat the primary tumor as well as the groin and pelvic nodes. 28,47,48,61 In patients who have clinically positive nodes, enlarged groin and pelvic nodes should be removed if possible, and the patient given postoperative groin and pelvic radiation.…”