On May 3rd, Lisa Pratt reported in Molecular Imaging the results since PERCIST’s introduction in 2009.  “The PET Response Criteria in Solid Tumors (PERCIST), published in May 2009 in the Journal of Nuclear Medicine, aim to propel PET from the murky realm of qualitative imaging to a quantitative breakdown of response to cancer treatment. However, transitioning PERCIST from proposal to practice remains a work-in-progress. Health Imaging explores the rationale for PERCIST, benefits of the model and barriers to its dissemination.”