Radiologic Heterogeneity in Responses to Anti–PD-1/PD-L1 Therapy in Metastatic Renal Cell Carcinoma

Abstract

Radiologic assessment of tumor response remains a challenge in patients treated with immune checkpoint inhibitors. In metastatic melanoma, for example, a spectrum of imaging patterns in response to immunotherapies have been recognized and associated with clinical benefit. In metastatic renal cell carcinoma (mRCC), less than half of patients treated with immune checkpoint inhibitors achieve objective responses, but some of the responses have been durable. In this series, five different imaging patterns of response and progression are described in mRCC patients treated with anti-PD-1/PD-L1 agents: (i) early and complete response, (ii) pseudoprogression, (iii) disease stability before ultimate response, (iv) mixed response with new lesions, and (v) early progression/primary refractory disease. The implications of the different imaging patterns of patient responses on disease prognosis are discussed and highlight the need for individualized patient assessment when using these novel immune-targeted agents.

The prognostic and predictive impact of inflammatory biomarkers in patients who have advanced‐stage cancer treated with immunotherapy

“…Radiographic assessment of treatment responses can be heterogeneous in patients who receive IO. 26 Changes in the values of these blood-based biomarkers around the time of the first set of restaging scans may further assist in clarifying patient status for situations in which the radiologic findings are inconclusive. These values would provide adjunctive data points on which to base the decision regarding whether the patient is deriving CB from treatment.…”

Prediction of Response to Immune Checkpoint Inhibitor Therapy Using Early-Time-Point18F-FDG PET/CT Imaging in Patients with Advanced Melanoma

“…Other tumors remain stable in size for a prolonged time, even after therapy has been stopped (3)(4)(5)(6). Indeed, a variety of radiologic responses to ICIs has been described, some of which are linked to therapeutic benefit (7,8). Because traditional RECIST or World Health Organization criteria may be insufficient to characterize outcomes after administration of immune-based antineoplastic drugs, immune-related response criteria (irRC (9)) are increasingly being incorporated into clinical trials of cancer immunotherapies (10,11).…”

Immunotherapy for genitourinary tumors

“…ICIs induce characteristic responses different from cytotoxic agents. In particular, pseudo progression, which is considered to occur as a result of infiltration of immune cells into tumors, must be considered when evaluating the treatment response to ICI . RECIST version 1.1 (RECIST v1.1) are widely used for assessing treatment responses in patients with advanced malignancies .…”

“…In particular, pseudo progression, which is considered to occur as a result of infiltration of immune cells into tumors, must be considered when evaluating the treatment response to ICI. 28,29 RECIST version 1.1 (RECIST v1.1) are widely used for assessing treatment responses in patients with advanced malignancies. 30 In general, especially in daily practice, once tumor progression is indicative of a progressive disease according to RECIST v1.1, the drug is terminated in most cases.…”