title: Computed tomography planned interstitial brachytherapy for recurrent gynecologic cancer.
abstract: OBJECTIVE
  To report outcomes and identify predictors of toxicity in patients undergoing reirradiation with interstitial brachytherapy (ISBT) for recurrent cancers of the female reproductive tract.
  
  
  METHODS
  Twenty-one patients received ISBT performed using (192)Ir sources (10 low dose rate and 11 high dose rate) at our institution between 2009 and 2013. Demographic, disease specific, treatment, toxicity, and outcome data were collected. Kaplan-Meier and proportional hazard models were used to estimate survival and logistic regression to model toxicity. A least absolute shrinkage and selection operator penalty was used to identify relevant predictors of outcome and toxicity.
  
  
  RESULTS
  Eleven patients had uterine cancer, 7 patients had cervical cancer, and 3 patients had vulvar cancer. One-year actuarial freedom from local-regional failure, progression-free survival (PFS), and overall survival were 71.5%, 66.0%, and 82.2%, respectively. Tumor size was a significant predictor of worse PFS and overall survival (1 cm increase in tumor size = hazard ratio [HR], 1.61; 95% confidence interval [CI]: 1.16, 2.62 for PFS; HR, 2.02; 95% CI: 1.21, 3.38). Grade 3 or higher vaginal, urinary, and rectal toxicity occurred in 28.5%, 9.5%, and 19% of patients, respectively. Urethra D0.1cc predicted for grade 2 or higher urinary toxicity (one equivalent dose in 2 Gy fraction increase = HR, 1.156; 95% CI: 1.001, 1.335).
  
  
  CONCLUSIONS
  Reirradiation with ISBT is both safe and effective. In patients with recurrent cancer, urethra D0.1cc predicts for increased urinary toxicity. Increased tumor size is a negative prognostic factor in patients receiving ISBT for cancer recurrence.
authors.affiliation: Department of Radiation Oncology, University of Louisville, Louisville, KY.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Amsbaugh
authors.affiliation: Department of Radiation Oncology, University of Louisville, Louisville, KY.
authors.forename: Neal
authors.initials: N
authors.lastname: Bhatt
authors.affiliation: Department of Radiation Oncology, University of Louisville, Louisville, KY.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hunter
authors.affiliation: Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, KY.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Gaskins
authors.affiliation: Department of Obstetrics Gynecology and Women's Health, University of Louisville, Louisville, KY.
authors.forename: Lynn
authors.initials: L
authors.lastname: Parker
authors.affiliation: Department of Obstetrics Gynecology and Women's Health, University of Louisville, Louisville, KY.
authors.forename: Daniel
authors.initials: D
authors.lastname: Metzinger
authors.affiliation: Department of Anesthesia and Perioperative Medicine, University of Louisville, Louisville, KY.
authors.forename: Ashley
authors.initials: A
authors.lastname: Amsbaugh
authors.affiliation: Department of Radiation Oncology, University of Louisville, Louisville, KY.
authors.forename: Keith
authors.initials: K
authors.lastname: Sowards
authors.affiliation: Department of Radiation Oncology, University of Louisville, Louisville, KY. Electronic address: Moataz.elghamry@louisville.edu.
authors.forename: Moataz
authors.initials: M
authors.lastname: El-Ghamry
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D005833:Genital Neoplasms, Female / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D058958:Organs at Risk / Q000528:radiation effects*; D011832:Radiation Injuries / Q000209:etiology*; D011880:Radiotherapy Planning, Computer-Assisted; D012007:Rectum / Q000528:radiation effects; D019233:Retreatment; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D014521:Urethra / Q000528:radiation effects; D014621:Vagina / Q000528:radiation effects
chemical_list: D007496:Iridium Radioisotopes
keywords: Gynecologic malignancy; Interstitial brachytherapy; Reirradiation