Mhlanga Joyce,  Siegel Marilyn

Final Pr. ID: Poster #: EDU-056

The Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) have gained widespread use in oncology clinical trials. RECIST 1.1 provides a standardized set of rules for response assessment in solid tumors using tumor shrinkage, based on standard imaging modalities. Standardized tumor response criteria are critically important in comparing results among clinical trials.

1) Review the steps in using the RECIST 1.1 guidelines
2) Present representative case examples

Baseline study: First step is identifying target (measurable) and non-target (non-measurable) lesions. Non-nodal target lesions need to be > 10 mm in long axis in axial plane only, while lymph nodes need to >15 mm in short axis. Target lesions include up to 2 measurable lesions per organ and 5 total lesions. Intravenous contrast is mandatory. CT is preferred imaging study but MRI can be substituted. All other lesions are categorized as non-target lesions. Finally, sum of the diameters for all target lesion is recorded.
Of note, bone lesions are not measurable, although an associated soft tissue mass is measurable. Sclerotic and lytic bone lesions are included as non-measurable disease. Nodes < 10 mm in short axis, pleural effusion, ascites and simple cysts are totally excluded from imaging response assessment.

Follow up studies: Sum of the diameters of all unequivocal target lesions is recorded and percent change from baseline or nadir is calculated. Non-target lesion status is recorded as absent, present or unequivocal progression. New lesions are also reported.
Overall response for target and nontarget lesions with or without new lesions is evaluated. RECIST 1.1 assigns four categories of response: complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD).

Future directions: Although increase in tumor size remains an important parameter for evaluating disease response, response may occur after an initial increase in tumor burden and regression of initial lesions may occur despite development of new lesions, especially with use of immunotherapy. This has led to new immunotherapy response criteria: Immune-related response criteria (irRC) and Immune-response RECIST (irRECIST).

Image-based outcome measures are commonly used to assess treatment response in clinical trials and have played a role in the regulatory drug approval of oncologic therapies. Therefore, it is imperative that radiologists understand the application of image-based response criteria. Read More

Authors:  Mhlanga Joyce , Siegel Marilyn

Keywords:  RECIST 1.1, Oncology, Clinical Trials

Willard Scott,  Barnes Craig,  Augustyn Robyn,  Thorkelson Marrit,  Chatfield Paige,  Hu Harry,  Towbin Richard,  Bardo Dianna,  Pfeifer Cory,  Dance Logan,  Bailey Smita,  Southard Richard,  Jorgensen Scott,  Biyyam Deepa,  Patel Mittun,  Cassell Ian

Final Pr. ID: Poster #: EDU-110

Accurate tumor measurement is essential in initial assessment of solid tumors. Furthermore, it is vital when evaluating treatment response. Change in tumor size determines whether a treatment course is effective, if treatment should be prolonged, or whether a more aggressive treatment or chemotherapy drug should be administered. Currently endorsed and widely used guidelines for tumor volume measurement include response evaluation criteria in solid tumors (RECIST), a one dimensional measure (cm) of target lesions which is not routinely the longest axis; World Health Organization (WHO), a 2 dimensional measure of the long and one short tumor axis (cm2) but is not a measure of volume; and Childrens Oncology Group (COG), a 3 dimensional ‘volume’ (cm3) measurement but does not account for shape of the tumor.

Pediatric oncology patients are almost exclusively cared for in major academic or community hospital settings where modern CT and MR scanners routinely produce direct or reconstructed multiplanar images. Therefore an evolution of tumor measurement, to determine tumor volume, must be forthcoming. Read More

Authors:  Willard Scott , Barnes Craig , Augustyn Robyn , Thorkelson Marrit , Chatfield Paige , Hu Harry , Towbin Richard , Bardo Dianna , Pfeifer Cory , Dance Logan , Bailey Smita , Southard Richard , Jorgensen Scott , Biyyam Deepa , Patel Mittun , Cassell Ian

Keywords:  RECIST, WHO, COG