Patient dosimetry audit for establishing local diagnostic reference levels for nuclear medicine CT

Abstract

A system for NMCT patient dose audit has been developed, but there are non-trivial challenges which make the process labour intensive. These include limited information provided by CRIS downloads, dependence on paper records and limited number of examinations available owing to the need to subdivide data. Advances in knowledge: This article demonstrates that a system can be developed for NMCT patient dose audit, but also highlights the challenges associated with such audit, which may not be encountered with more routine audit of radiology CT.

Determining and updating PET/CT and SPECT/CT diagnostic reference levels: A systematic review

“…Body region was another area that varied across studies. Several publications have asserted that variations in CT scan range or body region associated with oncological PET/CT protocols and SPECT/CT bone protocols depend on patient clinical indication demonstrating a lack of standardisation (42)(43)(44)(45) . For 18 F-FDG PET/CT procedures the most common CT range was varied from the mid-femora to the external auditory meatus, and from the top of the head to the feet for tumours that show a high probability of metastasis in the brain, skull or lower extremities, e.g.…”

“…The first and second scan ranges for the whole body CT protocol are started from the eyes to the thighs and from the vertex to the toes, respectively. For SPECT/CT, Gardner et al provides local DRL values for bone and neuro-endocrine SPECT/CT procedures takes into account different anatomical body regions and the purpose of CT used for each anatomical regions (45) .…”

“…Four different anatomical body regions were identified for neuro-endocrine SPECT/CT procedures known as abdomen, abdomen/pelvis, chest/abdomen/ pelvis, and head/chest/abdomen/pelvis and the DLP values for each anatomical body region were 280, 204, 204, and 377, and 373 mGy.cm respectively (45) . Furthermore, the scan length might be increased if the NM physician found a new metastatic lesion requiring additional CT investigation (18) .…”

“…Iball et al suggested that limiting the scan length to only the area requiring investigation would optimise radiation doses delivered from PET/CT and SPECT/CT examination used in British clinical centres (18) . Thus, an NDRL method for PET/CT and SPECT/CT should provide a clear description of the clinical indications in relation to PET/CT and SPECT/CT examinations, the administered radiopharmaceutical, and the scan range of anatomical regions (18,33,45) .…”

The 2020 national diagnostic reference levels for nuclear medicine in Japan

“…In the UK, the Institute of Physics and Engineering in Medicine Working Party proposed national DRLs for hybrid CT that were determined for each examination type and purpose of CT [ 15 ]. Gardner et al have developed four distinct dose mode ("low" for attenuation correction, "moderate" for localization, "standard" as diagnosis, and “metal” for orthopedic implants containing metal) based on scan purpose [ 16 ]. There is still room for further considerations of how to classify the DRLs for hybrid CT.…”