What is the annual TBI/TSET output calibration tolerance?

• A. 2% from baseline
• B. 0% from baseline
• C. ±1% from baseline
• D. ±3% from baseline

Answer: (A)

The main idea is how much the machine’s output can drift from its established baseline over a year. For TBI/TSET, keeping the delivered dose consistent year to year is crucial, so the annual calibration tolerance is set to stay close to that baseline. The annual output tolerance is within 2% of the baseline, meaning the yearly measured output should lie within plus or minus 2% of the original calibration value. This allows for normal long-term drift in equipment and dosimetry while keeping patient doses within clinically acceptable limits. Zero drift isn’t realistic, and tolerances tighter than this are uncommon for annual checks, while looser tolerances would risk dose variation beyond acceptable limits.