Radiologic Assessment of Response to Therapy: Comparison of RECIST Versions 1.1 and 1.0

Abstract

Improvements in radiologic imaging technology and therapeutic options available for management of tumors have necessitated the revision of guidelines for the imaging-based assessment of tumor response to therapy. The purpose of this article is to familiarize radiologists with the modifications to the Response Evaluation Criteria in Solid Tumors (RECIST) that have been incorporated in the latest version of the guidelines, RECIST 1.1. The most important differences between this version and the previous one, RECIST 1.0, include reductions in the maximum number of lesions per patient and per organ that may be targeted for measurement, augmentation of the criteria defining progressive disease, additional guidelines for reporting findings of lesions that are too small to measure and for measuring lesions that appear to have fragmented or coalesced at follow-up imaging, new criteria for characterizing lymphadenopathy, new criteria for selecting bone lesions and cystic lesions as targets for measurement, and the inclusion of findings at positron emission tomography among the indicators of disease response.

Guidelines for Diagnosis and Treatment of Primary Liver Cancer in China (2017 Edition)

“…During re-staging, PET can accurately visualize changes in anatomic structures or tumor recurrence and metastases at the site with a complicated anatomic structure (evidence level 2) [13, 14]. Regarding the response evaluation, PET is more sensitive and accurate for evaluating the response to molecular target drugs that act to inhibit tumor activity (evidence level 2) [20, 21]. PET/CT is beneficial for evaluating the extent of malignancy and the prognosis of tumors (evidence level 2) [15-17].…”

Risk of Hippocampal Metastases in Small Cell Lung Cancer Patients at Presentation and After Cranial Irradiation: A Safety Profile Study for Hippocampal Sparing During Prophylactic or Therapeutic Cranial Irradiation

“…CNS progression was defined as either development of a new metastatic brain lesion or 30% increase in the size of a target lesion since the last imaging study, according to the Response Evaluation Criteria In Solid Tumors (RECIST) (22).…”

Assessment of Liver Tumor Response to Therapy: Role of Quantitative Imaging

“…The four categories of tumor response in RECIST 1.1 are summarized in Table 1. There are four major differences between RECIST versions 1.0 and 1.1 as they relate to liver tumors (14)(15)(16), summarized as follows.…”

“…(c) As with its predecessors, RECIST 1.1 does not define the standard phase of contrast material enhancement for measuring specific tumors. This criterion may be important if the lesion is best seen during either the arterial or venous phase of enhancement (10,15,16).…”