title: MRI-guided high-dose-rate intracavitary brachytherapy for treatment of cervical cancer: the University of Pittsburgh experience.
abstract: OBJECTIVE
  Image-based brachytherapy is increasingly used for gynecologic malignancies. We report early outcomes of magnetic resonance imaging (MRI)-guided brachytherapy.
  
  
  METHODS
  Consecutive patient cases with FIGO stage IB1 to IVA cervical cancer treated at a single institution were retrospectively reviewed. All patients received concurrent cisplatin with external beam radiation therapy along with interdigitated high-dose-rate intracavitary brachytherapy. Computed tomography or MRI was completed after each application, the latter acquired for at least 1 fraction. High-risk clinical target volume (HRCTV) and organs at risk were identified by Groupe Européen de Curiethérapie and European SocieTy for Radiotherapy and Oncology guidelines. Doses were converted to equivalent 2-Gy doses (EQD2) with planned HRCTV doses of 75 to 85 Gy.
  
  
  RESULTS
  From 2007 to 2013, 128 patients, median 52 years of age, were treated. Predominant characteristics included stage IIB disease (58.6%) with a median tumor size of 5 cm, squamous histology (82.8%), and no radiographic nodal involvement (53.1%). Most patients (67.2%) received intensity modulated radiation therapy (IMRT) at a median dose of 45 Gy, followed by a median brachytherapy dose of 27.5 Gy (range, 25-30 Gy) in 5 fractions. At a median follow up of 24.4 months (range, 2.1-77.2 months), estimated 2-year local control, disease-free survival, and cancer-specific survival rates were 91.6%, 81.8%, and 87.6%, respectively. Predictors of local failure included adenocarcinoma histology (P<.01) and clinical response at 3 months (P<.01). Among the adenocarcinoma subset, receiving HRCTV D90 EQD2 ≥84 Gy was associated with improved local control (2-year local control rate 100% vs 54.5%, P=.03). Grade 3 or greater gastrointestinal or genitourinary late toxicity occurred at a 2-year actuarial rate of 0.9%.
  
  
  CONCLUSIONS
  This study constitutes one of the largest reported series of MRI-guided brachytherapy in North America, demonstrating excellent local control with acceptable morbidity. Dose escalation may be warranted when feasible for adenocarcinomas to offset the risk of local failure.
authors: Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Beant S
authors: BS
authors: Gill
authors: Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Hayeon
authors: H
authors: Kim
authors: Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Christopher J
authors: CJ
authors: Houser
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Joseph L
authors: JL
authors: Kelley
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Paniti
authors: P
authors: Sukumvanich
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Robert P
authors: RP
authors: Edwards
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: John T
authors: JT
authors: Comerci
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Alexander B
authors: AB
authors: Olawaiye
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Marilyn
authors: M
authors: Huang
authors: Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors: Madeleine
authors: M
authors: Courtney-Brooks
authors: Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. Electronic address: beriwals@upmc.edu.
authors: Sushil
authors: S
authors: Beriwal
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D010414:Pennsylvania; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D047368:Tumor Burden; D014495:Universities; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000532:radiotherapy*