Imaging biomarkers for evaluating tumor response: RECIST and beyond

Area of Science:

• Oncology
• Medical Imaging
• Cancer Therapeutics

Background:

• Response Evaluation Criteria in Solid Tumors (RECIST) is the standard for assessing cancer treatment response based on tumor size.
• New therapies like targeted and immunotherapies may not show response through size reduction alone.
• RECIST has shown limitations in accurately evaluating treatment efficacy for various cancers.

Purpose of the Study:

• To review the limitations of current RECIST criteria in evaluating novel anti-cancer drug responses.
• To highlight the need for advanced imaging biomarkers beyond RECIST.
• To introduce emerging imaging techniques for early detection of tumor response.

Main Methods:

• Literature review of RECIST criteria and its application in oncology.
• Analysis of studies reporting RECIST's reliability issues with new cancer therapies.
• Exploration of advanced imaging modalities as potential alternatives or complements to RECIST.

Main Results:

• RECIST's reliance on morphological changes is insufficient for therapies affecting tumor biology differently.
• Tumor necrosis and lack of progression indicate response, which RECIST may not capture.
• Several advanced imaging techniques show promise in assessing early treatment response.

Conclusions:

• Unmodified RECIST criteria are inadequate for evaluating response to modern cancer treatments.
• New imaging biomarkers assessing tumor viability and metabolism are crucial.
• Advanced techniques like PET, DWI, and dynamic CT/MRI offer superior assessment of therapeutic efficacy.