Evaluation of the response assessment criteria in newly diagnosed and recurrent glioblastoma

2020

Background: The Response Assessment in Neuro-Oncology (RANO) and modified RANO (mRANO) criteria are the two most widely used criteria to evaluate treatment response in glioblastoma (GBM) clinical trials. Unlike RANO, mRANO omits the evaluation of FLAIR sequence and requires a repeat scan to confirm responses. It also uses the post-radiation (RT) MRI as a baseline MRI in the newly diagnosed setting instead of the pre-RT MRI used in RANO. We sought to compare the 2 response assessment criteria and evaluate the differences between them in a large patient population. We also sought to compare them to immunotherapy RANO (iRANO) in patients who received immunotherapy. Methods: We conducted a retrospective review of consecutive patients with newly diagnosed (nGBM) and recurrent (rGBM) IDH wild-type GBM treated at Dana-Farber Cancer Institute from 2014 to 2020. Bidimensional measurements of enhancing disease and evaluation of FLAIR sequences were performed by two independent readers on patients’ brain MRIs obtained before change of treatment, and discrepancies were evaluated by a third reader. Dates of disease progression (PD) were identified using RANO, mRANO, iRANO, and other response assessment criteria variations. Spearman’s correlations between PFS and OS were calculated using an iterative multiple imputation method to account for any right-censoring. Results: 526 and 580 patients were included in the newly diagnosed and recurrent cohorts, respectively. Spearman’s correlations were not significantly different between RANO and mRANO in the nGBM (0.69 [95% CI 0.62 to 0.75] vs. 0.67 [0.60, 0.73]) and rGBM (0.45 [0.37, 0.52] vs. 0.50 [0.42, 0.57]) cohorts. Evaluation of FLAIR sequences did not improve the correlation between PFS and OS in patients who received antiangiogenic therapy. Addition of confirmation scans was associated with stronger Spearman’s correlations only when PD was identified within 12 weeks of completion of RT in the nGBM cohort, but did not affect the Spearman’s correlations in the rGBM cohort. The use of the post-RT MRI as a baseline was associated with a higher Spearman’s correlation in nGBM than the use of pre-RT MRI (0.67 [0.60, 0.73] vs. 0.53 [0.42, 0.62]). Among 98 patients with nGBM and 175 patients with rGBM who received immunotherapy, the Spearman’s correlations (nGBM and rGBM) with iRANO (0.63 [0.44, 0.76] and 0.34 [0.17, 0.49]) were similar to RANO (0.73 [0.60, 0.82] and 0.42 [0.28, 0.54]) and mRANO (0.65 [0.48, 0.77] and 0.43 [0.28, 0.56]). Conclusions: RANO and mRANO demonstrated similar correlation between PFS and OS. The evaluation of FLAIR can be omitted, while confirmation scans appear to be only beneficial in the nGBM settings during the first 12 weeks of completion of RT. There was a nonsignificant trend in favor of the use of post-RT MRI as the baseline scan in the nGBM setting. The application of iRANO criteria did not add significant benefit in patients who received immunotherapy.

Defining the optimal millimeter threshold for target lesion inclusion in the Response Assessment in Neuro-Oncology for Brain Metastases (RANO-BM) based on outcome prediction

e14003

Background: The Response Assessment in Neuro-Oncology for Brain Metastases (RANO-BM) is the standard for therapeutic response assessment in brain metastases (BM) patients. The criteria relies on a human reader to annotate target (≥10 mm) and non-target (<10mm) lesions of interest based on unidimensional measurement of lesion diameter on brain MRI. The change in the sum largest axial diameter of 5 target lesions (RANO-BM diameter) is then used to categorize intracranial response into 4 categories: complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Methods: Automating the RANO-BM criteria (AUTO-RANO-BM) has enabled the rapid modulation of the threshold diameter required for inclusion of a brain metastasis as a target lesion. In this study, diameters below the RANO-BM 10mm recommendation were utilized when calculating the RANO-BM diameter. The ability of the RANO-BM diameter to predict overall survival for BM patients was then evaluated in a Cox Proportional Hazards model. In a cohort of 175 immunotherapy-treated BM patients, the optimal threshold for the RANO-BM diameter as measured by Concordance Index (C-Index) was 5mm, suggesting that the RANO-BM criteria should be amended.

Estimated clinical efficacy and radiographic response characteristics of PD1 inhibition in newly diagnosed and recurrent glioblastoma in clinical practice: A report from the iRANO Working Group

2521

Background: Despite concerns of immunotherapy-induced inflammatory response during PD1 inhibition, questions remain as to the true incidence of inflammatory response and potential clinical implications. The goals of the project were to use GBM patients pooled from academic centers to estimate radiographic PFS and OS, as well as determine the incidence of immunotherapy-induced inflammatory response. Methods: 152 patients with newly diagnosed (N = 57) or recurrent (N = 95) GBM treated with either nivolumab or pembrolizumab from Dana-Farber (N = 88), UCLA (N = 35) or UCSF (N = 29) were included in this study. Radiographic progression was defined by a 25% increase in bidirectional measurements according to RANO. Results: Median PFS and OS for newly diagnosed patients was 162 and 520 days, respectively, while median PFS and OS for recurrent patients was 72 and 225 days, respectively. No difference in OS was observed in recurrent patients treated with nivolumab vs. pembrolizumab (P = 0.58), but recurrent patients treated with nivolumab trended toward a longer PFS (P = 0.097). Of the recurrent patients with OS and PFS data available and radiographic progression, 95% of them progressed within 6 mos of starting treatment. Median post-progression survival (PPS) in recurrent patients with PFS < 6 mos was 151 days, while PPS for patients with PFS > 6 mos was 178 days (P = 0.51). In the 77 recurrent patients who progressed within 6 mos, 36.4% had an OS that was > 9 mos, while 63.6% had an OS < 9 mos, suggesting the majority of patients with “early progression” also died early and a minority of patients had what could be considered “immune-related inflammation”. Of the 81 recurrent patients with documented progression, only 2.5% showed stabilization within 3 mos of first progression, 30.9% died before the 3-month confirmation scan could be obtained, 24.7% showed continued tumor growth by 3 months, and 48.1% had no follow-up confirmatory imaging exams. Of the 70 patients who progressed within 6 mos and had documented death, 2.9% had disease stabilization, 31.4% died before the 3-month confirmation, and 75.7% had either documented tumor growth or had no follow-up confirmatory imaging exams. Conclusions: This study suggests immunotherapy-induced inflammation followed by a favorable PPS is uncommon in GBM. While patients treated with other types of immunotherapy may exhibit different imaging characteristics, these data provide an important basis to refine the iRANO criteria.