title: Brachytherapy-emulating robotic radiosurgery in patients with cervical carcinoma.
abstract: OBJECTIVE
  To evaluate the technique, dosimetry, dose-volume-histograms (DVHs) and acute toxicity for CyberKnife® boost irradiation instead of intra-cervical brachytherapy in patients with cervical cancer.
  
  
  METHODS
  Eleven who were not suitable for brachytherapy with FIGO stage IIB-IIIB cervical cancer underwent primary chemoradiation. After fiducial implantation, T2 contrast-enhanced planning MRI and CT scans at 2-mm slice thickness were collected in the treatment position. The clinical target volume was defined as cervix + macroscopic residual tumour on MRI. Five fractions of 6 Gy each were prescribed to the target volume with a covering single dose 6 Gy. DVH parameters were evaluated for the target and organs at risk. Acute toxicity was documented once a week.
  
  
  RESULTS
  DmeanPTV ranged from 33.6-40 Gy, median 36.7 Gy with a coverage of the PTV calculated to 100% of the prescribed dose ranging from 93.0-99.3% (median 97.7%). For the PTV the median CN was 0.78 (range, 0.66 to 0.87) and the median CI was 1.28 (range 1.15 to 1.52). Gastrointestinal (GI) and genitourinary (GU) toxicity was mild. There was no grade 3 or higher GI and GU toxicity. After 6 months of follow up, there were no local recurrences. For the complete treatment, a median EQD2 to 1 cc and 2 cc of the bladder wall was 98.8 Gy and 87.1 Gy, respectively. Median EQD2 to 1 cc and 2 cc of the rectal wall was 72.3 Gy and 64 Gy, respectively, correlating with a risk < 10% for Grade 2-4 late toxicity.
  
  
  CONCLUSIONS
  CyberKnife robotic radiosurgery in patients with cervical cancer provides excellent target coverage with steep dose gradients toward normal tissues and safe DVH parameters for bladder, rectum and sigmoid. Acute toxicity was mild. Longer follow-up is needed to evaluate the oncological equality.
authors: Simone
authors: S
authors: Marnitz
authors: Christhardt
authors: C
authors: Köhler
authors: Volker
authors: V
authors: Budach
authors: Oliver
authors: O
authors: Neumann
authors: Anne
authors: A
authors: Kluge
authors: Waldemar
authors: W
authors: Wlodarczyk
authors: Ulrich
authors: U
authors: Jahn
authors: Bernhard
authors: B
authors: Gebauer
authors: Markus
authors: M
authors: Kufeld
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D005260:Female; D057918:Fiducial Markers; D006801:Humans; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted; D065287:Robotic Surgical Procedures / Q000379:methods*; D012371:Robotics / Q000379:methods; D002583:Uterine Cervical Neoplasms / Q000601:surgery*
references: Radiother Oncol. 2006 Jan;78(1):67-77
references: 16403584
references: Technol Cancer Res Treat. 2010 Oct;9(5):509-14
references: 20815422
references: Front Oncol. 2012 Mar 21;2:25
references: 22655266
references: Expert Rev Anticancer Ther. 2011 Jul;11(7):1069-75
references: 21806330
references: BMC Cancer. 2010 Nov 23;10:637
references: 21092235
references: Cancer. 1984 Jul 15;54(2):235-46
references: 6722748
references: Int J Radiat Oncol Biol Phys. 1998 Jan 15;40(2):515-24
references: 9457842
references: Int J Radiat Oncol Biol Phys. 2009 May 1;74(1):147-53
references: 18990511
references: Int J Radiat Oncol Biol Phys. 2008 Jul 1;71(3):772-8
references: 18207658
references: Int J Radiat Oncol Biol Phys. 1982 Nov;8(11):1887-95
references: 6818192
references: Int J Radiat Oncol Biol Phys. 2012 Feb 1;82(2):653-7
references: 21345618
references: Int J Radiat Oncol Biol Phys. 2005 May 1;62(1):118-24
references: 15850911
references: Int J Radiat Oncol Biol Phys. 2006 Feb 1;64(2):333-42
references: 16414369
references: Discov Med. 2010 Sep;10(52):255-62
references: 20875347
references: Int J Radiat Oncol Biol Phys. 2012 Jan 1;82(1):250-5
references: 21183288
references: Int J Radiat Oncol Biol Phys. 2012 Feb 1;82(2):e137-43
references: 21600704
references: Int J Radiat Oncol Biol Phys. 1997 Feb 1;37(3):731-6
references: 9112473