Factors influencing the use of adaptive radiation therapy in vulvar carcinoma

Fawzi Abuhijla; Samer Salah; Maysa Al-Hussaini; Issa Mohamed; Imad Jaradat; Abdulmajeed Dayyat; Hanan Almasri; Alaa Allozi; Ayah Arjan; Abdelatif Almousa; Ramiz Abu-Hijlih

doi:10.1016/j.rpor.2020.06.005

Factors influencing the use of adaptive radiation therapy in vulvar carcinoma

Rep Pract Oncol Radiother. 2020 Sep-Oct;25(5):709-713. doi: 10.1016/j.rpor.2020.06.005. Epub 2020 Jul 10.

Affiliations

¹ Department of Radiation Oncology, King Hussein Cancer Center, PO Box 1269, Amman 11941, Jordan.
² Department of Medical Oncology, King Hussein Cancer Center, PO Box 1269, Amman 11941, Jordan.
³ Department of Pathology, King Hussein Cancer Center, PO Box 1269, Amman 11941, Jordan.

Abstract

Aim: We aim to evaluate the variables affecting the frequency of adaptive radiotherapy (ART) in vulvar cancer.

Background: ART may be needed throughout a definitive RT course for vulvar carcinoma due to changes in patient's anatomy and tumor response.

Materials and methods: Charts of patients charts who had been treated with definitive concurrent chemo-radiotherapy for vulvar carcinoma, between January 2015 and December 2019 were inquired. Radiation therapy was delivered using intensity modulated radiotherapy (IMRT) with daily image-guided radiotherapy (IGRT). ART was defined as re-simulation and re-planning based on deformation in the irradiated volume by more than 1 cm. Univariate analysis was conducted to study the impact of patient's demographics as well as tumor characteristics on the frequency of ART.

Results: 22 patients were eligible for analysis. Median age at diagnosis was 55 years (range 43-82). Radiotherapy dose was 60-66 Gy over 30-35 fractions (fx). Median primary tumor volume was 30cc (9-140). Median Body Mass Index (BMI) was 32 (range 21-40). Thirteen out of 22 patients (59%) required ART, with median timing at 25 fx (19-31). On univariate analysis, larger primary tumor volume (> = 30cc) was associated significantly with increased frequency of ART (p value = 0.0005). There was no significant impact of ART on the frequency with respect to patient's age, BMI, tumor stage, grade and location.

Conclusion: Changes in radiation target volume are common among vulvar carcinoma patients who are treated with definitive radiotherapy, especially large primary tumors. This review highlights the importance of ART for patients with vulvar carcinoma treated with definitive radiotherapy.

Keywords: Adaptive; Factors; Radiotherapy; Vulva.