title: Assessment of radiation doses to the para-aortic, pelvic, and inguinal lymph nodes delivered by image-guided adaptive brachytherapy in locally advanced cervical cancer.
abstract: OBJECTIVE
  This study evaluated the dose delivered to lymph nodes (LNs) by brachytherapy (BT) and the effect of BT image-guided optimization on the LN dose.
  
  
  METHODS
  Twenty-five patients with locally advanced cervical cancer were retrospectively analyzed, 16 patients of them had LN involvement. The patients received whole pelvis intensity-modulated radiation therapy (45-50 Gy/25-30 fx) to whole pelvis and two fractions of MRI pulsed-dose-rate BT. The delineated LN groups were para-aortic, inguinal, common iliac (CI), external iliac, internal iliac, obturator, and presacral. For each LN group, D98%, D50%, and D2% (the dose that covers 98%, 50%, and 2% of the volume, respectively) were evaluated for optimized and standard BT plans. The correlation between total reference air kerma (TRAK) and D50% of the LN groups was evaluated.
  
  
  RESULTS
  BT contributed considerable dose (mean D50% was 3.8-6.2 Gy equivalent total dose in 2-Gy fractions) to the pelvic LN (external iliac, internal iliac, obturator, and presacral) in optimized plans, whereas less-dose contribution to CI, para-aortic, and inguinal (mean D50% was 0.5-1.9 Gy equivalent total dose in 2-Gy fractions) was observed. Optimized plans delivered less dose to the LNs as compared with standard plans, although differences only amounted to a mean of 0.2-0.9 Gy (D50%). TRAK showed a significant correlation with LN D50% for all LN groups except CI, although only 19-38% of the dose variation could be explained by the TRAK.
  
  
  CONCLUSIONS
  BT contributes considerable dose to pelvic LNs and should be considered in the evaluation of total LN doses.
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Radiation Oncology, NCI, Cairo University, Cairo, Egypt. Electronic address: sandy@oncology.dk.
authors.forename: Sandy M I
authors.initials: SM
authors.lastname: Mohamed
authors.affiliation: Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Torben
authors.initials: T
authors.lastname: Aagaard
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Lars U
authors.initials: LU
authors.lastname: Fokdal
authors.affiliation: Department of Radiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Erik M
authors.initials: EM
authors.lastname: Pedersen
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Lindegaard
authors.affiliation: Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark; Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Kari
authors.initials: K
authors.lastname: Tanderup
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D005260:Female; D006801:Humans; D007264:Inguinal Canal; D015182:Lymphatic Irradiation / Q000379:methods*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D010388:Pelvis; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*
keywords: Brachytherapy; Cervical cancer; Inguinal lymph node; MRI guided; Para-aortic lymph node; Pelvic lymph node; Radiation dose