SKIN DOSE, EFFECTIVE DOSE AND RELATED RISK IN TRANSCATHETER AORTIC VALVE IMPLANTATION (TAVI) PROCEDURES: IS THE...

Area of Science:

• Medical Physics
• Radiology
• Radiation Oncology

Background:

• Transcatheter aortic valve implantation (TAVI) involves radiation exposure.
• Estimating radiation doses and associated risks is crucial for patient safety.
• Current TAVI patient populations are typically elderly, with skin injuries being the primary radiation concern.

Purpose of the Study:

• To estimate conversion coefficients for maximum entrance skin dose (MESD) and effective dose (E) in TAVI procedures.
• To evaluate the risk of exposure-induced cancer death (REID) for TAVI patients, particularly younger individuals.
• To assess the impact of patient age on radiation-induced cancer risk.

Main Methods:

• Conversion coefficients (CCS and CCE) were calculated using dose-area product (DAP).
• Effective doses and REID were estimated for 22 patients using PCXMC software.
• Maximum entrance skin doses (MESDs) were measured for 15 patients using Gafchromic film.

Main Results:

• Estimated conversion coefficients were 9.7±1.5 mSv/Gy cm² for skin dose (CCS) and 0.24±0.02 mSv/Gy cm² for effective dose (CCE).
• The risk of exposure-induced cancer death (REID) ranged from 1:9900 to 1:1400.
• Reducing patient age to 40-50 years increased REID by a factor of 2 for females and 1.5 for males, with the lung identified as the organ at risk.

Conclusions:

• Radiation-induced skin injuries are the main risk for the current elderly TAVI population.
• Cancer induction risk must be considered for younger TAVI patient populations.
• Accurate dose estimation and risk assessment are vital for optimizing TAVI procedures and patient management.