Abstract
Whole pelvis radiation therapy (WPRT) in premenopausal women with cervical cancer can cause permanent ovarian damage, resulting in premature menopause. Oophoropexy, often considered as an initial step, demonstrates safety of sparing 1 ovary at the cost of delay in initiating WPRT. Therefore, we dosimetrically compared volumetric modulated arc radiotherapy (VMAT) and intensity modulated proton therapy (IMPT) techniques to allow for ovarian-sparing WPRT. Ten patients previously treated for cervical cancer at our institution were included in this institutional review board-approved analysis. A modified clinical treatment volume (CTV) was designed, sparing 1 ovary (left or right), as determined by the physician (ovarian-sparing CTV) and disease extent, including physical exam, positron emission tomography/computed tomography and magnetic resonance imaging. An ovarian-sparing planning target volume was determined as the ovarian-sparing CTV+5 mm for patients who were supine and 7 mm for those who were prone. All plans were calculated to a dose of 45 Gy with specific optimization goals for target volumes, while attempting to maintain a mean ovary dose (Dmean) < 15 Gy. Dosimetric goals were compared across the 2 modalities using the Mann-Whitney U test. Both treatment modalities were able to achieve primary clinical goal coverage to the uterus/cervix (P = .529, comparing VMAT versus IMPT), ovarian-sparing CTV (P = .796) and ovarian-sparing planning target volume (P = .004). All 10 IMPT plans were able to accomplish the ovary objective (14.0 ± 1.66 Gy). However, only 4 of the 10 VMAT plans were able to achieve a Dmean < 15 Gy to the prioritized ovary, with an average dose of 15.3 ± 4.10 Gy. Sparing an ovary in women undergoing WPRT for cervical cancer is dosimetrically feasible with IMPT without sacrificing coverage to important clinical targets. Future work will incorporate the brachytherapy dose to the ovarian-sparing CTV and assess the clinical response of this technique as a means to preserve ovarian endocrine function.
Highlights
Cervical cancer remains fairly common in the United States, with a reported 13,240 estimated new cases in 2018 [1]
Whole pelvis radiation therapy (WPRT) with brachytherapy remains absolutely necessary for cure [2,3,4]
Ovarian transposition is a way to preserve ovarian function in gynecologic malignancies [6], but, due to logistics, this can lead to a delay in initiating therapy, which can result in inferior clinical outcomes [7] and increasing cost of care
Summary
Cervical cancer remains fairly common in the United States, with a reported 13,240 estimated new cases in 2018 [1]. Whole pelvis radiation therapy (WPRT) with brachytherapy remains absolutely necessary for cure [2,3,4]. Ovarian transposition is a way to preserve ovarian function in gynecologic malignancies [6], but, due to logistics, this can lead to a delay in initiating therapy, which can result in inferior clinical outcomes [7] and increasing cost of care. It is an invasive procedure that comes with risks and a reported 35% failure rate in preserving ovarian function [8]. Ovarian transposition occasionally fails as the transposed ovary can fall back into the pelvis before initiation of pelvic radiation therapy or during treatment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
