title: Model assessment of individual tumor control rate and adverse effects in comparing locally advanced cervical cancer treatment using intracavitary with and without interstitial brachytherapy.
abstract: OBJECTIVE
  This study assessed the modeled probability of tumor control and organ at risk toxicities in locally advanced cervical cancer in patients treated by external beam radiation plus brachytherapy using intracavitary combined with interstitial brachytherapy (IC/IS) vs. intracavitary brachytherapy (IC) alone.
  
  
  METHODS
  Twenty cervical cancer patients with a mean HR-CTV volume of 47.4 cm3and a mean width of 54 mm were planned with both IC/IS and IC brachytherapy alone. A probit model was utilized to model 3-year (3-yr) local control rate (LC), 3-yr cancer specific survival rate (CSS), and the adverse effect (AE) of the organ at risk by using a modeled data set from multiple institutions. Modeling results were used to estimate the LC, CSS, and AE of the treatments in this study.
  
  
  RESULTS
  Using the IC/IS technique, an EQD2increase of 12.3 Gy to D90(from 76.1 Gy to 88.3 Gy) of HR-CTV is expected to increase 3-yr LC and 3-yr CSS by 12.5%, and 11.0%, respectively. Comparing IC/IS to IC alone, the expected G2+AE were 7.7% vs. 7.9% for the bladder, and 5.9% vs. 6.8% for the rectum.
  
  
  CONCLUSIONS
  The IC/IS technique improved dose coverage to the HR-CTV without significantly increasing dose to 2 cm3of the organ at risk (OAR) surrounding it. With different regimens of EBRT combined with BT, IC/IS can be used to increase the probability of LC and CSS, or decrease the risk of AE.
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Hsiang-Chi
authors.initials: HC
authors.lastname: Kuo
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Keyur J
authors.initials: KJ
authors.lastname: Mehta
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Yaparpalvi
authors.affiliation: Albert Einstein College of Medicine, New York; Department of Epidemiology and Population Health, New York, USA.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Shankar
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: William
authors.initials: W
authors.lastname: Bodner
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Madhur
authors.initials: M
authors.lastname: Garg
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York.
authors.forename: Amanda
authors.initials: A
authors.lastname: Rivera
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Tomé
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, New York; Albert Einstein College of Medicine, New York.
authors.forename: Shalom
authors.initials: S
authors.lastname: Kalnicki
keywords: adverse effect; brachytherapy; cervical cancer; tumor control