pseudoprogression
Pronunciation: SOO-do-pro-GRESH-un
Apparent tumor progression on imaging that actually represents inflammation or treatment effect rather than true disease advancement.
Full Definition
Pseudoprogression is a phenomenon where imaging studies suggest tumor growth or new lesions, but these findings actually represent inflammation, necrosis, or other treatment-related changes rather than true disease progression. This occurrence is particularly common following immunotherapy, radiation therapy, or certain targeted therapies. Distinguishing pseudoprogression from true progression can be challenging and may require additional imaging, tissue sampling, or clinical observation over time. Recognition of pseudoprogression is crucial to avoid premature treatment discontinuation in patients who may actually be responding to therapy. Updated response criteria like iRECIST have been developed to address this challenge in immunotherapy trials.
Usage
Usage note: Document the timeline and treatment context when pseudoprogression is suspected.
In Context
- "The apparent tumor growth was determined to be pseudoprogression following immunotherapy." — Radiology interpretation
- "Continued treatment despite initial pseudoprogression led to eventual tumor shrinkage." — Case discussion