title: Intra-operative pubic arch interference during prostate seed brachytherapy in patients with CT-based pubic arch interference of < or =1cm.
abstract: OBJECTIVE
  There are only a few reports on the frequency of intra-operative pubic arch interference (I-PAI) during prostate seed brachytherapy (PB).
  
  
  METHODS
  Two hundred and forty-three patients with a CT-based pubic arch interference (PAI) of < or =1 cm and a prostate volume of < or =50-60 cc underwent PB. Those patients requiring needle repositioning by > or =0.5 cm on the template were scored as having I-PAI. The incidence of I-PAI and its impact on biochemical control were analyzed.
  
  
  RESULTS
  Intra-operative PAI was encountered in 47 (19.3%) patients. Forty two patients (17.3%) had I-PAI in 1-2 needles, two (0.8%) had I-PAI in four needles and three patients (1.2%) had I-PAI in six needles. Overall, 1.4% of needles required repositioning due to I-PAI. BMI>27 kg/m(2) and wider (>75 mm) pubic bone separation at mid ramus (PS-ML) were associated with a lower incidence of I-PAI. At a median follow-up of 50.1 months, the 3- and 5-year bPFS was 97.3% and 95.2%, respectively. The 5-year bPFS rates for patients with and without I-PAI were 95.6% and 95%, respectively (p=0.28).
  
  
  CONCLUSIONS
  The use of CT-based PAI of < or =1cm as a selection criterion for PB is a simple and reliable method for minimizing the incidence of I-PAI and maintaining excellent biochemical control rates.
authors.affiliation: Department of Radiation Oncology, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Samir V
authors.initials: SV
authors.lastname: Sejpal
authors.forename: Vythialingam
authors.initials: V
authors.lastname: Sathiaseelan
authors.forename: Irene B
authors.initials: IB
authors.lastname: Helenowski
authors.forename: James M
authors.initials: JM
authors.lastname: Kozlowski
authors.forename: Michael F
authors.initials: MF
authors.lastname: Carter
authors.forename: Robert B
authors.initials: RB
authors.lastname: Nadler
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Dalton
authors.forename: Kevin T
authors.initials: KT
authors.lastname: McVary
authors.forename: William W
authors.initials: WW
authors.lastname: Lin
authors.forename: John E
authors.initials: JE
authors.lastname: Garnett
authors.forename: John A
authors.initials: JA
authors.lastname: Kalapurakal
mesh_terms: D000368:Aged; D001918:Brachytherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000532:radiotherapy*; D011630:Pubic Bone / Q000000981:diagnostic imaging*; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*