Organs at Risk (OAR) [PART 1]
What is included in the plan evaluation? - answer- Examine dose distribution
- Check adequate coverage of target volume
- Reduce potential harm to OAR
- Achieve goal of treatment
- Comply w/ guidelines for Tolerance Dose
- Check Dose constraints
What is OAR also known as? - answer'Critical structures' as stated in ICRU Report 50
What is Tolerance Dose ( Scientific Publication 1972)? - answerIt represents the
radiation dose that would result in the risk of severe complications w/in 5 yrs. So as
dose increases so does risk
Who introduced this and when? - answerRubin & Cassarett 1972
What does TD5/5 mean? - answer5% probability of developing severe complications
w/in 5 yrs (following RT)
What does TD50/5 mean? - answer50% probability of developing severe complications
w/in 5 yrs (following RT)
What is the Emami Paper? - answerIt is a scientific publication which contains all
reviewed available data on normal tissue tolerance to RT. Organs are divided into third/
two-thirds and whole organ volumes and concept of dose tolerance is applied. The
concept of TD5/5 and TD50/5 is also applied
What does QUANTEC (2010) stand for? - answerQuantitative Analysis of Normal
Tissue Effects in Clinic
What is QUANTEC (2010)? - answerThis scientific publication aimed to provide
practical guidance on the relationship between b/w dose-volume and end-point tissue
complications. It also published dose guidelines for dose constraints. So if the dose
threshold is exceeded, it leads to endpoint complications
What does RTOG stand for? - answerRadiation Therapy Oncology Group (RTOG)
clinical trails
What is RTOG? - answerThey published reports on clinical trials and dose constraints
E.g. What does V70 < 20% mean? - answerThe volume of the normal rectum receiving
70Gy should be less than 20%
What is included in the plan evaluation? - answer- Examine dose distribution
- Check adequate coverage of target volume
- Reduce potential harm to OAR
- Achieve goal of treatment
- Comply w/ guidelines for Tolerance Dose
- Check Dose constraints
What is OAR also known as? - answer'Critical structures' as stated in ICRU Report 50
What is Tolerance Dose ( Scientific Publication 1972)? - answerIt represents the
radiation dose that would result in the risk of severe complications w/in 5 yrs. So as
dose increases so does risk
Who introduced this and when? - answerRubin & Cassarett 1972
What does TD5/5 mean? - answer5% probability of developing severe complications
w/in 5 yrs (following RT)
What does TD50/5 mean? - answer50% probability of developing severe complications
w/in 5 yrs (following RT)
What is the Emami Paper? - answerIt is a scientific publication which contains all
reviewed available data on normal tissue tolerance to RT. Organs are divided into third/
two-thirds and whole organ volumes and concept of dose tolerance is applied. The
concept of TD5/5 and TD50/5 is also applied
What does QUANTEC (2010) stand for? - answerQuantitative Analysis of Normal
Tissue Effects in Clinic
What is QUANTEC (2010)? - answerThis scientific publication aimed to provide
practical guidance on the relationship between b/w dose-volume and end-point tissue
complications. It also published dose guidelines for dose constraints. So if the dose
threshold is exceeded, it leads to endpoint complications
What does RTOG stand for? - answerRadiation Therapy Oncology Group (RTOG)
clinical trails
What is RTOG? - answerThey published reports on clinical trials and dose constraints
E.g. What does V70 < 20% mean? - answerThe volume of the normal rectum receiving
70Gy should be less than 20%
