Tumor Response Criteria

The dominant standard for solid tumor response in clinical trials. Measures the longest diameter of up to 5 target lesions (max 2 per organ) by CT or MRI.

The original landmark tumor response framework. Uses the product of the longest diameter and its perpendicular as a surrogate for tumor area.

Adapted for HCC; measures only the viable (arterially enhancing) portion of a tumor, not overall size, reflecting biologic behavior after locoregional therapy.

Designed for immunotherapy trials. Allows unconfirmed progressive disease (iUPD) to be followed by a confirmation scan 4 to 8 weeks later before declaring true PD (iCPD).

An early immunotherapy adaptation using bidimensional measurements. New lesions are incorporated into total tumor burden rather than triggering automatic PD.

Developed by Genentech/Roche from atezolizumab trial data. Like iRECIST, allows response assessment after initial PD, but differs by allowing target lesion reversion to be captured in best overall response and by not automatically counting isolated new lesions as PD.

The primary PET-based response framework. Uses SULpeak (lean body mass normalized peak SUV) of the single most metabolically active lesion to quantify response.

One of the earliest FDG-PET response frameworks, using SUVmax percent change from baseline. Defined categories for early and late response assessment.

A visual 5-point scoring scale for FDG-PET in lymphoma, comparing lesion uptake to two reference organs: mediastinal blood pool and liver. Forms the PET scoring backbone for the Lugano classification.

The current standard for staging and response assessment in lymphoma. Integrates FDG-PET (using Deauville scores) with CT measurements into a unified response framework, replacing the 2007 Cheson criteria.

A 5-point structured reporting framework for somatostatin receptor (SSTR) PET/CT, analogous to PSMA-RADS for prostate cancer. Classifies lesions by likelihood of neuroendocrine tumor involvement to standardize interpretation and guide peptide receptor radionuclide therapy (PRRT) patient selection.

Adapts the PERCIST framework for immunotherapy, introducing unconfirmed PET progressive metabolic disease (UPMD) requiring confirmation; analogous to iRECIST's iUPD.

Designed for primary brain tumors (gliomas). Integrates bidimensional T1-enhancing lesion measurements with T2/FLAIR changes and clinical status. Addresses pseudoprogression from chemoradiation.

Adapted RANO framework for brain metastases in clinical trials; distinguishes radiation necrosis from true progression and accounts for steroid effects.

Pre-Lugano lymphoma response standard integrating CT and PET. Introduced PET into routine lymphoma staging and response; foundational for subsequent Lugano criteria.

Governs response assessment in prostate cancer trials, addressing the bone scan flare phenomenon, PSA kinetics, and the multi-compartment nature of metastatic prostate disease.

Japanese criteria for liver cancer integrating both tumor size changes and enhancement characteristics. Widely used in Japan for HCC response after locoregional and systemic therapy.

Developed for gastrointestinal stromal tumors (GIST) treated with imatinib. Adds CT tumor attenuation (Hounsfield units) to size as a response parameter, capturing the myxoid degeneration and necrosis that imatinib induces without shrinkage.

An early viable-tumor framework for HCC predating mRECIST. Uses bidimensional measurement of the contrast-enhancing (viable) tumor area rather than total tumor size, recognizing that locoregional therapies induce necrosis without shrinkage.

Adapted for malignant pleural mesothelioma (MPM), whose rind-like growth pattern along the pleural surface makes standard RECIST unidimensional diameter measurements unreliable. Measures tumor thickness perpendicular to the chest wall or mediastinum at multiple CT levels.

A suite of pediatric-specific CNS tumor response criteria developed by an international working group, recognizing that adult RANO criteria cannot be directly applied to children due to differing tumor biology, variable enhancement patterns, cystic components, and the poor correlation between tumor size and survival in many pediatric CNS tumors.

The original standardized response framework for high-grade gliomas, predating RANO. Uses bidimensional measurement of contrast-enhancing tumor on CT or MRI, integrated with corticosteroid dose and neurological status. Largely superseded by RANO but foundational to the field.

Extends RANO criteria specifically for glioma patients on immunotherapy. Within the first 6 months of treatment, radiologic progression on imaging without clinical deterioration does not mandate treatment discontinuation; a 3-month observation period is required before confirming true PD.

A Lugano Classification refinement for lymphoma patients receiving immunomodulatory therapy (checkpoint inhibitors, lenalidomide). Introduces Indeterminate Response (IR) as a holding category for apparent progression that may represent pseudoprogression or a flare reaction, requiring biopsy or confirmatory imaging within 12 weeks.

An international working group proposal to align lymphoma response assessment with RECIST methodology by adopting unidimensional (single longest diameter) measurements, making lymphoma trials more comparable to solid tumor trials and enabling basket trial designs across histologies.

Standardized framework for PSMA PET assessment in prostate cancer; covers staging, biochemical recurrence localization, and treatment response to PSMA-directed therapy.

Addresses the historically difficult problem of bone lesion response evaluation, where conventional RECIST performs poorly due to osteoblastic/osteolytic appearance changes after therapy.

Research-stage refinement of RECIST using semiautomated 3D volumetric segmentation rather than single-diameter measurement; more sensitive to asymmetric or irregular tumor morphology.

A 2023 unification of all prior RANO variants (RANO-HGG, RANO-LGG, mRANO, iRANO) into a single treatment-agnostic framework covering all adult glioma grades. Introduces post-radiotherapy MRI as the mandatory baseline, adds volumetric thresholds alongside bidimensional ones, and removes non-enhancing progression as a standalone PD criterion for enhancing GBM.