PET-CTPET-CT

Low dose vs. Diagnostic CTLow dose vs. Diagnostic CT

Chris Semine MD 1/11/11Chris Semine MD 1/11/11

Low Dose PET-CTLow Dose PET-CT

Standard PET scan is performed and Standard PET scan is performed and fused to a low dose CT scan used to fused to a low dose CT scan used to identify the location (localize) the foci identify the location (localize) the foci of abnormal uptake of abnormal uptake

The “CT” is not a diagnostic The “CT” is not a diagnostic examination. The radiation dosage is examination. The radiation dosage is too low to generate fully diagnostic too low to generate fully diagnostic images.images.

PET/ Diagnostic CTPET/ Diagnostic CT

Every case of PET has a concurrent Every case of PET has a concurrent diagnostic quality (full radiation dose diagnostic quality (full radiation dose CT scan with or without contrast) of CT scan with or without contrast) of the head, neck, chest, abdomen and the head, neck, chest, abdomen and pelvis.pelvis.

Five diagnostic level CT examinations Five diagnostic level CT examinations are performed and fused to the PET are performed and fused to the PET regardless of whether the patient regardless of whether the patient needs them at this time or not.needs them at this time or not.

Radiation exposureRadiation exposure

Loc PET-CTLoc PET-CT

PET 5mSVPET 5mSV Loc CT 15 mSVLoc CT 15 mSV

TOTAL: 20mSVTOTAL: 20mSV

Dx PET-CTDx PET-CT

PET 5mSVPET 5mSV Head CT 4 mSVHead CT 4 mSV Neck CT 6 mSVNeck CT 6 mSV Chest CT 7 mSVChest CT 7 mSV Abd CT 7.5 mSVAbd CT 7.5 mSV Pelvis CT 7.5 mSVPelvis CT 7.5 mSV

TOTAL: 42 mSVTOTAL: 42 mSV

COSTCOST

Localizing PET-CTLocalizing PET-CT

PET: $1000PET: $1000

Loc CT: $0Loc CT: $0

TOTAL: $1000TOTAL: $1000

Dx PET-CTDx PET-CT

PET: $1000PET: $1000 CT Head $600CT Head $600 CT Neck $800CT Neck $800 CT Chest $800CT Chest $800 CT Abdomen $800CT Abdomen $800 CT Pelvis $800CT Pelvis $800

TOTAL: $4800TOTAL: $4800

Conclusions:Conclusions: Patients that need to have diagnostic CTs of Patients that need to have diagnostic CTs of

chest, abdomen, and pelvis at approximately the chest, abdomen, and pelvis at approximately the same time as the PET are candidates to have the same time as the PET are candidates to have the combined PET and diagnostic CT examinations combined PET and diagnostic CT examinations (with or without contrast, as indicated).(with or without contrast, as indicated).

Patient who are not due to have diagnostic CTs of Patient who are not due to have diagnostic CTs of the head, neck, chest, abdomen and pelvis at the the head, neck, chest, abdomen and pelvis at the same time as the PET would be better served to same time as the PET would be better served to have a PET/CT with localizing CT only, and have have a PET/CT with localizing CT only, and have the diagnostic CT (not necessarily all 5 CTs) done the diagnostic CT (not necessarily all 5 CTs) done at the appropriate time.at the appropriate time.