title: Cervical gross tumor volume dose predicts local control using magnetic resonance imaging/diffusion-weighted imaging-guided high-dose-rate and positron emission tomography/computed tomography-guided intensity modulated radiation therapy.
abstract: OBJECTIVE
  Magnetic resonance imaging/diffusion weighted-imaging (MRI/DWI)-guided high-dose-rate (HDR) brachytherapy and (18)F-fluorodeoxyglucose (FDG) - positron emission tomography/computed tomography (PET/CT)-guided intensity modulated radiation therapy (IMRT) for the definitive treatment of cervical cancer is a novel treatment technique. The purpose of this study was to report our analysis of dose-volume parameters predicting gross tumor volume (GTV) control.
  
  
  METHODS
  We analyzed the records of 134 patients with International Federation of Gynecology and Obstetrics stages IB1-IVB cervical cancer treated with combined MRI-guided HDR and IMRT from July 2009 to July 2011. IMRT was targeted to the metabolic tumor volume and lymph nodes by use of FDG-PET/CT simulation. The GTV for each HDR fraction was delineated by use of T2-weighted or apparent diffusion coefficient maps from diffusion-weighted sequences. The D100, D90, and Dmean delivered to the GTV from HDR and IMRT were summed to EQD2.
  
  
  RESULTS
  One hundred twenty-five patients received all irradiation treatment as planned, and 9 did not complete treatment. All 134 patients are included in this analysis. Treatment failure in the cervix occurred in 24 patients (18.0%). Patients with cervix failures had a lower D100, D90, and Dmean than those who did not experience failure in the cervix. The respective doses to the GTV were 41, 58, and 136 Gy for failures compared with 67, 99, and 236 Gy for those who did not experience failure (P<.001). Probit analysis estimated the minimum D100, D90, and Dmean doses required for ≥90% local control to be 69, 98, and 260 Gy (P<.001).
  
  
  CONCLUSIONS
  Total dose delivered to the GTV from combined MRI-guided HDR and PET/CT-guided IMRT is highly correlated with local tumor control. The findings can be directly applied in the clinic for dose adaptation to maximize local control.
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Pawel
authors.initials: P
authors.lastname: Dyk
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Naomi
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Baozhou
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Todd A
authors.initials: TA
authors.lastname: DeWees
authors.affiliation: Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Fowler
authors.affiliation: Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Vamsi
authors.initials: V
authors.lastname: Narra
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Garcia-Ramirez
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Julie K
authors.initials: JK
authors.lastname: Schwarz
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri; Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri; Division of Gynecologic Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri; Alvin J. Siteman Cancer Center, Washington University School of Medicine, St Louis, Missouri. Electronic address: pgrigsby@wustl.edu.
authors.forename: Perry W
authors.initials: PW
authors.lastname: Grigsby
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods; D018288:Carcinoma, Small Cell / Q000473:pathology / Q000532:radiotherapy; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D015641:Radiography, Interventional / Q000379:methods; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000532:radiotherapy*