Hi Colin,
That is not what RM has published in the recent past:
1: Eur J Cancer. 2005 Apr;41(6):908-21.
Technological advances in radiotherapy for the treatment of localised prostate
cancer.
Mangar SA, Huddart RA, Parker CC, Dearnaley DP, Khoo VS, Horwich A.
Academic Unit of Radiotherapy and Oncology, The Royal Marsden NHS Foundation
Trust and The Institute of Cancer Research, Downs Road, Sutton SM2 5NG, UK.
stephenmangar@supaworld.comThere is good evidence that radiation dose escalation in localised prostate
cancer is associated with increased cell kill. The traditional two-dimensional
(2D) technique of treatment planning and delivery is limited by normal tissue
toxicity, such that the dose that can be safely delivered to the prostate by
external beam radiotherapy is 65-70 Gy. Several technological advances over the
last 20 years have enhanced the precision of external beam radiotherapy (EBRT),
and have resulted in improved outcomes. The three-dimensional conformal
radiotherapy (3D-CRT) approach reduces the dose-limiting late side-effect of
proctitis and has allowed for dose escalation to the whole prostate to 78 Gy.
More recently, intensity modulated radiotherapy (IMRT), an advanced form of
conformal therapy, has resulted in reduced rectal toxicity when using doses
greater than 80 Gy. In addition, IMRT can potentially escalate the dose to
specific parts of the prostate where there are resistant subpopulations of tumour
clonogens, or can be used to extend the high-dose region to pelvic lymph nodes.
The addition of androgen deprivation to conventional radiotherapy has an impact
on survival and local control. Initial hormone therapy causes cytoreduction of
the prostate cancer allowing for a reduction in radiotherapy volume as well as an
additive effect on cell kill. Long-term adjuvant androgen deprivation has been
shown to improve overall survival in more advanced tumours. Prostate
brachytherapy is now a recognised treatment for those with low-risk disease. It
achieves similar long-term outcome to other treatment modalities. Brachytherapy
can be used as monotherapy for localised disease, or as boost treatment following
conventional EBRT for locally advanced disease. New techniques are available to
improve the precision of both target definition and treatment verification. This
so-called image-guided radiotherapy will help to enhance the accuracy of dose
delivery by correcting both for inter-fraction positional variation and for
intra-fraction movement of the prostate in real-time and will allow for tighter
tumour margins and avoidance of normal tissues, thereby enhancing the safety of
treatment.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 15808957 [PubMed - indexed for MEDLINE]
Best regards,
RalphV :ralph4: :ile: