**4. Paediatric dose estimations**

#### **4.1 RADAR—OLINDA/EXM 2**

Based on the OLINDA/EXM version 2.0 software and on 2007 recommendations of the ICRP, a new generation of voxel-based, realistic human computational phantoms was developed by the RADAR committee of the SNMMI.

It was used to develop the dose estimates as well as the most recent biokinetic models. These estimates will be made available in electronic form and can be modified and updated, as models are changed and new radiopharmaceuticals are added, MIRD Pamphlet No. 21 [8].

RADAR Dose Estimates Report in 2018 based on OLINDA/EXM Version 2.0 for Radiopharmaceutical Dose Estimates [9].


The ICRP has a method for internal dose calculations, originally described in ICRP Publication 30. This schema has been repeated, with modifications, several times, the latest being in ICRP Publication 130.

In many ICRP documents, slightly different names are given to some terms, but all the concepts are identical [8, 9].

OLINDA/EXM 2.0 used biokinetic models for 100 radioisotopes and adult and paediatric phantoms in order to develop dose estimate tables. Data within the ICRP task group on radiopharmaceutical dosimetry was considered. Tables for males and females were generated for 1-y olds, 5-y olds, 10-y olds, 15-y olds and adults.

The dose estimate tables give male and female dose values for approximately 25 target organs, as well as sex-averaged values for the five phantom-ages considered (1-y olds, 5-y olds, 10-y olds, 15-y old and adults). In these estimations, individual organ doses are given in units of equivalent dose (e.g., mSv) and not of absorbed dose (e.g., mGy), as quality factors applied may be non-unity for some emitters. For example, OLINDA/ EXM 2.0 uses:


Biokinetic models for nearly 100 radiopharmaceuticals can be used with the OLINDA/EXM 2.0 paediatric phantoms to develop dose estimate tables. Male and female tables for 1-year-olds, 5-year-olds, 10-year-olds, 15-year-olds can be generated.

In ICRP Publication 103, a sex-averaged rule is described for the development of relative data.

Individual organ doses are given in units of equivalent dose (mSv) and not in units of absorbed dose (mGy).
