title: Intracavitary combined with CT-guided interstitial brachytherapy for locally advanced uterine cervical cancer: introduction of the technique and a case presentation.
abstract: We report a new technique of brachytherapy consisting of intracavitary combined with computed tomography (CT)-guided interstitial brachytherapy for locally advanced cervical cancer. A Fletcher-Suit applicator and trocar point needles were used for performing high-dose rate brachytherapy under in-room CT guidance. First, a tandem and ovoids were implanted into the patient's vagina and uterus by conventional brachytherapy method. Based on clinical examination and MRI/CT imaging, operating radiation oncologists decided the positions of insertion in the tumor and the depth of the needles from the upper surface of the ovoid. Insertion of the needle applicator was performed from the vaginal vault inside the ovoid within the tumor under CT guidance. In treatment planning, dwell positions and time adaptations within the tandem and ovoids were performed first for optimization based on the Manchester system, and then stepwise addition of dwell positions within the needle was continued. Finally, dwell positions and dwell weights were manually modified until dose-volume constraints were optimally matched. In our pilot case, the dose of D90 to high-risk clinical target volume was improved from 3.5 Gy to 6.1 Gy by using our hybrid method on the dose-volume histogram. D1cc of the rectum, bladder and sigmoid colon by our hybrid method was 4.8 Gy, 6.4 Gy and 3.5 Gy, respectively. This method consists of advanced image-guided brachytherapy that can be performed safely and accurately. This approach has the potential of increasing target coverage, treated volume, and total dose without increasing the dose to organs at risk.
authors.affiliation: Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Wakatsuki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohno
authors.forename: Daisaku
authors.initials: D
authors.lastname: Yoshida
authors.forename: Shin-ei
authors.initials: SE
authors.lastname: Noda
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Saitoh
authors.forename: Kei
authors.initials: K
authors.lastname: Shibuya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Katoh
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Takeo
authors.initials: T
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*