Medical Physicists - Nuclear Medicine

“Child-size” the Radiopharmaceutical Doses Administered to Patients

The medical physicists are responsible for proper operational order of different imaging equipment, maintaining image quality, managing patient radiation dose, providing training/education to employees and discussing radiation issues with parents and providers. Because of their expertise on radiation issues, medical physicists can provide valuable guidance on “child-sizing” everyday procedures for technologists and nuclear medicine physicians who may be more habituated to an adult practice. They are central to ensuring the practice of as low as reasonably achievable (ALARA) for pediatric patients.

List of procedures
2014 Update of North American Consensus Guidelines for Pediatric administered Radiopharmaceutical activities

Radiation Dose and rRsk

  • Radiation dose may be different in children as compared to adults due to patient size, organ size and orientation and organ distribution of administered radiopharmaceutical. 
  • Estimates of critical organ and effective dose in common pediatric nuclear medicine procedures are listed in the table below. However please note that these estimates are averages over a wide range of patients at each age and do not take into consideration individual differences in anatomy and physiology from the standard models. 
  • Assessing the risk associated with exposure to ionizing radiation involves applying models that use both epidemiologic and biologic data to extrapolate from the available data to the dosimetric region of interest. Such extrapolation is not straightforward. 
  • Much of the current understanding about the risk of exposure to ionizing radiation for humans is based on the Life Span Study of the survivors of the bombings of Hiroshima and Nagasaki as reported by the Radiation Effects Research Foundation. 
  • The consensus is to assume that the risk at the lower doses with medical radiation can best be estimated by a linear extrapolation from higher doses for radiation protection purposes. 

It has become increasingly more important that nuclear medicine practitioners—including physicians, physicists, technologists, and other members of patient care teams effectively communicate with the referring providers and with patients and families about the medical use of radiation, the level of radiation exposure, and the potential risk.

Further Reading
 Outline: Radiation Dose and Risk in Pediatric Nuclear Medicine - Frederic H. Fahey, DSc, S. Ted Treves, MD and S. James Adelstein
Minimizing and Communicating Radiation Risk in Pediatric Nuclear Medicine, Fahey FH, Treves ST, Adelstein SJ. J Nucl Med. 2011; 52:1240-1251.

Additional Reading Material and Resources
 Society of Nuclear Medicine and Molecular Imaging (SNMMI)
The Society for Pediatric Radiology (SPR)
 SNMMI and combined SNMMI and ACR practice guidelines
International Atomic Energy Agency (IAEA) rPOP site
 
Radiology Info
National Council on Radiation Protection and Measurements (NCRP)
 Image Wisely- Radiation safety in adult medical imaging
 

Nuclear Medicine Resources

Medical Professionals

Parents

 

Radiation Dose Resources

SNMMI’s Dose Optimization Task Force has created two new online tools to help educate imaging professionals on best practices for pediatric and adult nuclear medicine:

 

The Pediatric Injected Activity Tool reports recommended injected activity for pediatric patients based on the North American consensus guidelines and the European Association of Nuclear Medicine guidelines. With this tool, specify the nuclear medicine procedure and the pediatric patient’s weight to find the recommended administered activity for the patient.

The Nuclear Medicine Radiation Dose Tool provides convenient access to guidelines and radiation dose estimates (effective dose and critical organ dose) for many nuclear medicine exams. With this tool, specify the nuclear medicine procedure, the injected activity, and the patient model (gender, age) to calculate the effective dose for this procedure.

 

 

Acknowledgements

S. Ted Treves, MD, Chair
Image Gently Nuclear Medicine Initiative 

Michael J. Gelfand,  MD, Past-President
SNMMI Pediatric Imaging Council, Cincinnati Children's Hospital Medical Center

Marguerite T. Parisi, MD, MS Ed., Chair
SPR Nuclear Medicine Committee, Seattle Children's Hospital

Larry Binkovitz, MD, President
SNMMI Pediatric Imaging Council, Mayo Clinic

Stephanie Spottswood, MD, Sec-Treasurer
SNMMI Pediatric Imaging Council, Vanderbilt University

Frederic Fahey, DSc, Physicist,
Children's Hospital Boston

Dominique Delbeke, MD, PhD, 2009-10
SNMMI President, Vanderbilt University 

Nanci A. Burchell, MBA, CNMT, FSNMTS
Children's Mercy Hospitals and Clinics, Kansas City, MO

Joanne Louis, CNMT, Children's Hospital Boston
Adam Alessio, PhD, Medical Physicist, Seattle Children's