ICRU : ICRU 83

Several days ago, our lecturer asked us to find out what ICRU stands for and what does it means. Then, we were given a task on ICRU 83. So today, we would like to share with you some informations about ICRU and focus on ICRU 83.

What is ICRU ?

ICRU stands for International Commission on Radiation Units and Measurements. it has principal objective on the development of internationally acceptable recommendations regarding :

1. Quantities and units of radiation and radioactivity.
2. Procedures that is suitable for the measurements and applications of these quantities in clinical radiology and radiobiology.
3. physical data needed in the application of these procedures, the use of which tends to assure uniformity in reporting.

source : google

ICRU 83

ICRU 83 : Prescribing, Recording and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT)

source : google

This ICRU Report are closely related to the previous ICRU Reports 50, 62,71 &78.
It emphasize on :

1. Gross Tumour Volume (GTV)
2. Clinical Target Volume (CTV)
3. Planning Target Volume (PTV)
4. Organ at Risk (OAR)
5. Planning organ-at-risk Volume (PRV)
6. Internal Target Volume (ITV)
7. Treated Volume (TV)
8. Remaining Volume at Risk (RVR) 

As a summary, this report discusses on :

1. For malignant tumour, CTV should always be associated with the GTV .
2. the use of dose-volume histograms(DVHs) for the specification of absorbed dose is inherent to the treatment modality
3. Describes optimization techniques, which can control the compromise of absorbed-dose homogeneity in the PTV with dose reduction in the PRV.
4. Designate the sets of treatment goals as the "planning aims" to differentiate them from the "prescription" .
5. Recommendations concerning absorbed-dose reporting evolve from previous ICRU recommendations while attempting to retain a relationship with the previous recommendations.
6. Recommends that the median absorbed dose, specified by D50% should be reported as it is considered to correspond best with the previously defined dose at the ICRU references point.
7. Recommends that in low gradient situation , define as a relative change of absorbed dose that is less than 20% per cm in any direction, that 85% of target volume absorbed dose samples should be within 5%

More info on ICRU , U can visit this link below : 

download icru-83

icru 83 journal 

icru
icru 62
icru 50

icru official website