title: Interstitial brachytherapy vs. intensity-modulated radiation therapy for patients with cervical carcinoma not suitable for intracavitary radiation therapy.
abstract: OBJECTIVE
  Interstitial brachytherapy (IBT) is the standard alternative treatment for patients with cervical carcinoma not suitable for intracavitary radiotherapy. There is an emerging belief that intensity-modulated radiotherapy (IMRT) has the potential to replace IBT. We aimed to compare the dosimetry achieved by IBT and IMRT in such patients.
  
  
  METHODS
  The CT imaging data, previously used for IBT planning of 12 patients with cervical carcinoma, were transferred to IMRT planning system to generate parallel IMRT plans. Prescribed dose to the planning target volume (PTV) was 20Gy delivered in 2-weekly high-dose-rate fractions of 10Gy each with IBT (biologically equivalent dose [BED10] 40Gy) and 33Gy/13 fractions/2.5 wk with IMRT (BED10 41Gy). For comparison, dose-volume parameters for target and organs at risk were recorded and expressed in terms of BED10 and BED3, respectively.
  
  
  RESULTS
  For PTV, the mean D95 (dose received by 95% of PTV) was better with IBT (57.16Gy vs. 41.47Gy, p=0.003). The mean conformity index was 0.94 and 0.90 with IBT and IMRT, respectively (p=0.034). IBT delivered significantly reduced doses to 1.0cc (Dmax), 5.0cc (D5 cc), 50% (D50), and 75% (D75) of bladder volume as compared with IMRT. The mean rectal Dmax was significantly better with IBT as compared with IMRT (54.64Gy vs. 62.63Gy, p=0.02).
  
  
  CONCLUSIONS
  IBT provides superior PTV coverage and organs at risk sparing to IMRT. Thus, IBT remains the standard treatment for patients with cervical carcinoma unsuitable for intracavitary radiotherapy.
authors: Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi, India. sharmadn@hotmail.com
authors: Daya Nand
authors: DN
authors: Sharma
authors: Ajeet Kumar
authors: AK
authors: Gandhi
authors: Seema
authors: S
authors: Sharma
authors: Goura Kisor
authors: GK
authors: Rath
authors: Pandjatcharam
authors: P
authors: Jagadesan
authors: Pramod Kumar
authors: PK
authors: Julka
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*