Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST)

Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) make use of positron emission tomography (PET) to provide functional information and therebyto help determine tumortumuor viability. 

Positron Emission Tomography Response Criteria in Solid Tumors, used with 2-[fluorine 18]fluoro-2-deoxy- d-glucose (FDG) positron emission tomography (PET).

The criteria consist of four response categories are: complete metabolic response, partial metabolic response, progressive metabolic disease, and stable metabolic disease. 

Complete Metabolic Response (CMR)

• Complete

  complete resolution of 18F-FDG uptake within the measurable target lesion

  • so that it is less than mean liver activity and
  • so that it is at the level of surrounding background blood pool activity.
• Disappearancedisappearance of all other lesions to background blood pool levels.
• Nono new suspicious 18F-FDG avid lesions.
• Ifif progression by according to RECIST criteria, must verify with follow up

Partial Metabolic Response (PMR)

• Reductionreduction of a minimum of 30% in target measurable tumortumour 18F-FDG SUL peak, with absolute drop in SUL of at least 0.8 SUL units.
• Nono increase >30% of SUL or size in all other lesions
• Nono new lesions

Stable Metabolic Disease (SMD)

• Notno CMR, PMR, or Progressiveprogressive metabolic disease (PMD)
• No new lesions

Progressive Metabolic Disease (PMD)

• >30% increase in 18F-FDG SUL peak, with >0.8 SUL units increase in tumortumour SUV peak from the baseline scan in pattern typical of tumortumour and not of infection/treatment effect.
• Oror visible increase in the extent of 18F-FDG tumortumour uptake.
• Oror new 18F-FDG avid lesions which are typical of cancer and not related to treatment effect orand/or infection.

Acronyms used above

• SUL = standardized uptake value corrected for lean body mass
• SULpeak = peak SUL in a spherical 1-cm3 VOI 
• VOI = volume of interest