Which element in a dosimetric plan is used to determine progression?

• A. Expected outcomes
• B. Progression criteria
• C. Safety checks
• D. Modality choice

Answer: (B)

Progression criteria define objective thresholds that tell you when a disease is getting worse during treatment. In a dosimetric plan, these criteria set specific benchmarks—such as changes in tumor size on imaging, new or growing lesions, or shifts in metabolic activity—that indicate progression rather than stability or response. When measurements meet these predefined thresholds, the team can reassess the plan, deciding whether to continue as is, escalate, or modify the treatment approach. This keeps progression assessment standardized and decision-making transparent rather than relying on a single observation.

Expected outcomes describe what you hope to achieve after treatment, not when to change course during therapy. Safety checks monitor adverse effects and tolerability, not whether the disease itself is progressing. Modality choice is about selecting the treatment method, not about defining progression during the course of treatment.