On 2015 Nov 18, David Keller commented:

One DaTscan exposes basal ganglia to an ionizing radiation dose equal to 21 CT scans, for what benefit?

According to the DaTscan product information, this radio-pharmaceutical exposes the basal ganglia to 42.5 mSv of ionizing radiation, equivalent to having 21 brain CT scans [1], a level of radiation exposure with unknown effects on the already injured neurons of the substantia nigra (SN). Indeed, no clinical study has assessed the possible worsening of Parkinson's disease caused by a DaTscan, by means of accelerated death of SN neurons due to radiation exposure.

The gold standard used in this study is clinical diagnosis, which causes zero radiation exposure to the SN, and a significantly more sensitive and specific diagnostic yield. Why, then, should any clinician order a DaTscan, at least until we know the effects of 42.5 mSv of ionizing radiation on the sick SN neurons of a Parkinson's patient?

Reference:

1: Keller DL. Proposal for a clinical trial to test the safety of a widely-used radionuclide scan. Comment on PMID: 26236969. In: PubMed Commons [Internet]. 2015 Sept 15 [cited 2015 Nov 20]. Available from http://www.ncbi.nlm.nih.gov/pubmed/26236969#cm26236969_11818

On 2015 Nov 18, David Keller commented:

One DaTscan exposes basal ganglia to an ionizing radiation dose equal to 21 CT scans, for what benefit?

According to the DaTscan product information, this radio-pharmaceutical exposes the basal ganglia to 42.5 mSv of ionizing radiation, equivalent to having 21 brain CT scans [1], a level of radiation exposure with unknown effects on the already injured neurons of the substantia nigra (SN). Indeed, no clinical study has assessed the possible worsening of Parkinson's disease caused by a DaTscan, by means of accelerated death of SN neurons due to radiation exposure.

The gold standard used in this study is clinical diagnosis, which causes zero radiation exposure to the SN, and a significantly more sensitive and specific diagnostic yield. Why, then, should any clinician order a DaTscan, at least until we know the effects of 42.5 mSv of ionizing radiation on the sick SN neurons of a Parkinson's patient?

Reference:

1: Keller DL. Proposal for a clinical trial to test the safety of a widely-used radionuclide scan. Comment on PMID: 26236969. In: PubMed Commons [Internet]. 2015 Sept 15 [cited 2015 Nov 20]. Available from http://www.ncbi.nlm.nih.gov/pubmed/26236969#cm26236969_11818