title: Dose volume analysis of radiotherapy for inoperable patients with stage I-II endometrial carcinoma.
abstract: This study aims to assess the efficacy and toxicity of definitive radiotherapy for early-stage endometrial carcinoma. The correlation between CT-based dosimetric parameters and clinical outcomes is also evaluated. Between 2002 and 2006, 10 medically inoperable patients with T1-2 endometrial carcinoma were treated with radiotherapy alone. A combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) was used for 9 patients, and one was treated with HDR-ICBT alone. Dose prescription of HDR-ICBT was determined in reference to CT images at brachytherapy, and a total dose of 22-24 Gy in 4 fractions was delivered to the outer perimeter of the uterine corpus. Dose-volume parameters of the gross tumor volume (GTV), clinical target volume (CTV), and organs at risk were assessed retrospectively using the dose-volume histograms derived from the CT image-based treatment planning system. After a median follow-up of 55 months, 9 patients were alive without evidence of recurrence. One patient died from liver cirrhosis 17 months after radiotherapy. Severe acute and late toxicities were not observed in any of the patients. Average minimum dose to 90% of GTV and CTV (D90) was 88.0 and 45.9 Gy(EQD2), respectively. The minimum dose delivered to 2 cc of the most irradiated volumes of the rectum and sigmoid colon (D(2cc)) was 78.9 and 65.9 Gy(EQD2), respectively. These patients developed Grade 1 late complications. In this study, stage I-II endometrial carcinoma was well-controlled locally with minimum late toxicity by radiotherapy alone with HDR-ICBT. 3D image-based brachytherapy may potentially deliver a sufficiently high dose to the whole tumor without significant increase in dose to surrounding normal tissues.
authors.affiliation: Hidaka Hospital, Gunma 370-0001, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ohkubo
authors.forename: Shingo
authors.initials: S
authors.lastname: Kato
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kiyohara
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuruoka
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tamaki
authors.forename: Shin-ei
authors.initials: SE
authors.lastname: Noda
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohno
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D018269:Carcinoma, Endometrioid / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D016889:Endometrial Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome