PMID- 16885177
OWN - NLM
STAT- MEDLINE
DCOM- 20061127
LR  - 20161124
IS  - 1748-880X (Electronic)
IS  - 0007-1285 (Linking)
VI  - 79
IP  - 947
DP  - 2006 Nov
TI  - Dose escalation to combat hypoxia in prostate cancer: a radiobiological study on 
      clinical data.
PG  - 905-11
AB  - Earlier studies have demonstrated that hypoxic regions exist in human prostate 
      cancer and the degree of hypoxia correlates with the treatment outcome of 
      radiotherapy. Using the concept of the clinical oxygen enhancement ratio (COER), 
      the linear-quadratic (LQ) model was extended to account for the effect of tumour 
      hypoxia. The clinical data collected at the Fox Chase Cancer Center for prostate 
      cancer were analysed based on the LQ model as well as the tumour control 
      probability (TCP) model. The LQ and TCP parameters (alpha = 0.15 Gy (-1), 
      alpha/beta = 3.1 Gy and the number of clonogens K = 10(6) approximately 10(7) 
      cells) determined in earlier studies were used to derive the COER for prostate 
      cancer: COER = 1.4 with a standard confidence interval (CI) of (1.2, 1.8). The 
      result is consistent with the in vitro OER measurements of human tumour cell 
      lines under chronic hypoxia conditions. This implies that a higher dose is needed 
      to overcome tumour hypoxia. For prostate tumours, the prescription dose required 
      to overcome tumour hypoxia is 165 Gy (CI: 153 approximately 186 Gy) for permanent 
      125I implants and 88 Gy (CI: 74 approximately 118 Gy) in 2 Gy fractions for 
      external-beam radiotherapy. The impact of LQ parameters on the calculations of 
      COER and dose escalation was discussed. This study provides a preliminary 
      estimate of the dose escalation needed to overcome tumour hypoxia based on 
      clinical data. More clinical data with better statistics and longer follow-up 
      time are required to further tune the radiobiological modelling of hypoxia for 
      prostate cancer.
FAU - Wang, J Z
AU  - Wang JZ
AD  - Department of Radiation Medicine, James Cancer Hospital and Solove Research 
      Institute, The Ohio State University, Columbus, OH 43210, USA. wang.993@osu.edu
FAU - Li, X A
AU  - Li XA
FAU - Mayr, N A
AU  - Mayr NA
LA  - eng
PT  - Journal Article
DEP - 20060802
PL  - England
TA  - Br J Radiol
JT  - The British journal of radiology
JID - 0373125
SB  - IM
MH  - Brachytherapy/methods
MH  - Dose-Response Relationship, Radiation
MH  - Humans
MH  - Hypoxia/etiology/*radiotherapy
MH  - Male
MH  - Prostatic Neoplasms/complications/*radiotherapy
MH  - Treatment Outcome
EDAT- 2006/08/04 09:00
MHDA- 2006/12/09 09:00
CRDT- 2006/08/04 09:00
PHST- 2006/08/04 09:00 [pubmed]
PHST- 2006/12/09 09:00 [medline]
PHST- 2006/08/04 09:00 [entrez]
AID - 18700614 [pii]
AID - 10.1259/bjr/18700614 [doi]
PST - ppublish
SO  - Br J Radiol. 2006 Nov;79(947):905-11. doi: 10.1259/bjr/18700614. Epub 2006 Aug 2.