Computed tomography for preoperative shoulder arthroplasty planning: lifetime malignancy risk

Area of Science:

• Radiology
• Oncology
• Orthopedic Surgery

Background:

• Computed tomography (CT) is standard for shoulder arthroplasty planning, but involves ionizing radiation exposure.
• Patient safety concerns necessitate evaluating cancer risks from these imaging procedures.

Purpose of the Study:

• To compare the lifetime cancer risks of conventional and low-dose shoulder CT protocols.
• To inform clinical practice regarding radiation exposure in preoperative planning.

Main Methods:

• Calculated effective dose (ED) for conventional (8.0 mSv) and low-dose (1.4 mSv) shoulder CT.
• Utilized the Biological Effects of Ionizing Radiation VII report to determine lifetime attributable risk (LAR) of cancer and number needed to harm (NNH) based on age and sex.

Main Results:

• Low-dose CT showed substantially lower LAR and higher NNH compared to conventional CT across all age groups and sexes.
• For a 50-year-old man, LAR was 0.0071% with low-dose CT versus 0.0405% with conventional CT.
• For a 50-year-old woman, LAR was 0.0095% with low-dose CT versus 0.0541% with conventional CT.

Conclusions:

• The use of preoperative shoulder CT requires careful consideration of lifetime cancer risks, particularly for younger women.
• Widespread adoption of low-dose CT protocols is recommended to mitigate radiation-induced cancer risks.