TY - JOUR
T1 - Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy
T2 - A report from the American Society for Radiation Oncology
AU - Nag, Subir
AU - Demanes, D. Jeffrey
AU - Hagan, Michael
AU - Rivard, Mark J.
AU - Thomadsen, Bruce R.
AU - Welsh, James S.
AU - Williamson, Jeffrey F.
N1 - Funding Information:
Conflicts of interest: Bruce R. Thomadsen, PhD, James S. Welsh, MD, Jeffrey F. Williamson, PhD, and Subir Nag, MD, have served on the Advisory Committee on the Medical use of Isotopes (ACMUI) of the Nuclear Regulatory Commission (NRC). Their opinions expressed here are in their private capacity as radiation oncologists and medical physicists and not as a representative of the NRC. While Mark J. Rivard, PhD, is a consultant to GE HealthCare, Inc., IsoRay Medical, Inc., Nucletron, B.V., Varian Medical Systems, Inc., and Xoft, Inc., he has not received any support directly related to this project. Jeffrey F. Williamson, PhD, is the principal investigator of a Varian and Philips research contract. Michael Hagan, MD has a research grant from Oncura Corp. James S. Welsh, MD, has received honorarium as a speaker from TomoTherapy, Inc. D. Jeffrey Demanes, MD, has not declared any conflict of interest.
PY - 2011/10
Y1 - 2011/10
N2 - Purpose: The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. Methods and Materials: The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. Results: The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. Conclusions: ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.
AB - Purpose: The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. Methods and Materials: The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. Results: The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. Conclusions: ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.
UR - http://www.scopus.com/inward/record.url?scp=80053587122&partnerID=8YFLogxK
U2 - 10.1016/j.prro.2011.05.001
DO - 10.1016/j.prro.2011.05.001
M3 - Article
C2 - 24174998
AN - SCOPUS:80053587122
SN - 1879-8500
VL - 1
SP - 218
EP - 223
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 4
ER -