title: MRI-guided brachytherapy in locally advanced cervical cancer: Small bowel [Formula: see text] and [Formula: see text] are not predictive of late morbidity.
abstract: To establish dose-volume effect correlations for late small bowel (SB) toxicities in patients treated for locally advanced cervical cancer with concomitant chemoradiation followed by pulsed-dose rate MRI-guided adaptive brachytherapy.
  
  
  
  Patients treated with curative intent and followed prospectively were included. The SB loops closed to CTV were delineated, but no specific dose constraint was applied. The dosimetric data, converted in 2-Gy equivalent, were confronted with the occurrence of late morbidity assessed using the CTC-AE 3.0. Dose-effect relationships were assessed using mean-dose comparisons, log-rank tests on event-free periods, and probit analyses.
  
  
  
  A total of 115 patients with a median followup of 35.5 months were included. Highest grade per patient was: Grades 0 for 17, 1 for 75, 2 for 20, and 3 for 3. The mean [Formula: see text] and [Formula: see text] were, respectively, 68.7 ± 13.6 Gy and 85.8 ± 33.1 Gy and did not differ according to event severity (p = 0.47 and p = 0.52), even when comparing Grades 0-1 vs. 2-4 events (68.0 ± 12.4 vs. 71.4 ± 17.7 Gy; p = 0.38 and 83.7 ± 26.4 vs. 94.5 ± 51.9 Gy; p = 0.33). Log-rank tests were performed after splitting the cohort according to four [Formula: see text] levels: >80 Gy, 70-79 Gy, 60-70 Gy, and <60 Gy. No difference was observed for Grades 1-4, Grades 2-4, or Grades 3-4 (p = 0.21-0.52). Probit analyses showed no correlation between the dosimetric parameters and probability of Grades 1-4, 2-4, or 3-4 events (p = 0.19-0.48).
  
  
  
  No significant dose-volume effect relationships were demonstrated between the [Formula: see text] and [Formula: see text] and the probability of late SB morbidity. These parameters should not limit the pulsed-dose rate brachytherapy optimization process.
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France. Electronic address: claire1.petit@gustaveroussy.fr.
authors.forename: Claire
authors.initials: C
authors.lastname: Petit
authors.affiliation: Department of Medical Physics, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dumas
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France; Molecular Radiotherapy, INSERM 1030, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Chargari
authors.affiliation: Department of Medical Physics, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Martinetti
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Maroun
authors.affiliation: Department of Medical Physics, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Kaya
authors.initials: K
authors.lastname: Doyeux
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Tailleur
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Haie-Meder
authors.affiliation: Department of Radiation Oncology, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France; Molecular Radiotherapy, INSERM 1030, Gustave Roussy Cancer Campus Grand Paris, Université Paris-Saclay, Villejuif, F-94805, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Mazeron
mesh_terms: D000230:Adenocarcinoma / Q000628:therapy*; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D018196:Carcinoma, Adenosquamous / Q000628:therapy*; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006801:Humans; D007410:Intestinal Diseases / Q000209:etiology; D007421:Intestine, Small; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D009017:Morbidity; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000628:therapy*
keywords: Cervical cancer; Dose–volume parameters; Image-guided adaptive brachytherapy; Morbidity; Normal tissue complication probability; Small bowel