pseudoresponse
Pronunciation: SOO-doh-response
Apparent tumor shrinkage on imaging that does not represent true therapeutic response, often caused by anti-angiogenic therapy effects.
Full Definition
Pseudoresponse describes the phenomenon where tumors appear to decrease in size on conventional imaging due to reduced contrast enhancement rather than actual cell death or tumor shrinkage. This is commonly observed with anti-angiogenic therapies like bevacizumab, which normalize tumor vasculature and reduce vascular permeability, leading to decreased contrast enhancement without necessarily affecting tumor cell viability. Advanced imaging techniques such as diffusion-weighted imaging or perfusion studies may help distinguish pseudoresponse from true response. Medical editors must understand this concept to accurately interpret imaging-based response assessments in clinical trials.
Usage
Usage note: Contrasts with pseudoprogression (apparent worsening). Both represent imaging artifacts that can confound response assessment.
In Context
- "The apparent tumor shrinkage was attributed to pseudoresponse rather than genuine therapeutic effect." — Imaging assessment report
- "Anti-angiogenic therapy may induce pseudoresponse by normalizing tumor vasculature." — Clinical trial protocol