Response Evaluation Criteria in Cancer of the liver version 6 (Response Evaluation Criteria in Cancer of the Liver 2021 revised version).

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation or transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2021 by the Liver Cancer Study Group of Japan based on the 2019 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2021 is inclusion of RECIST version 1.1 and modified RECIST as response evaluation criteria in systemic therapy for HCC. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Progressive Desmoid Tumor: Radiomics Compared With Conventional Response Criteria for Predicting Progression During Systemic Therapy-A Multicenter Study by the French Sarcoma Group.

OBJECTIVE. The response of desmoid tumors (DTs) to chemotherapy is evaluated with Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) in daily practice and clinical trials. MRI shows early change in heterogeneity in responding tumors due to a decrease in cellular area and an increase in fibronecrotic content before dimensional response. Heterogeneity can be quantified with radiomics. Our aim was to develop radiomics-based response criteria and to compare their performances with clinical and radiologic response criteria. MATERIALS AND METHODS. Forty-two patients (median age, 38.2 years) were included in this retrospective multicenter study because they presented with progressive DT and had an MRI examination at baseline, which we refer to as "MRI-0," and an early MRI evaluation performed after the first chemotherapy cycle (mean time after first chemotherapy cycle, 3 months [SD, 28 days]), which we refer to as "MRI-1." After signal intensity normalization, voxel size standardization, discretization, and segmentation of DT volume on fat-suppressed contrast-enhanced T1-weighted imaging, 90 baseline and delta 3D radiomics features were extracted. Using cross-validation and least absolute shrinkage and selection operator-penalized Cox regression, a radiomics score was generated. The performances of models based on the radiomics score, modified Response Evaluation Criteria in Solid Tumors, European Association for the Study of the Liver criteria, Cheson criteria, Choi criteria, and revised Choi criteria from MRI-0 to MRI-1 to predict progression-free survival (PFS, as defined by RECIST 1.1) were assessed with the concordance index. The results were adjusted for performance status, tumor volume, prior chemotherapy, current chemotherapy, and ß-catenin mutation. RESULTS. There were 10 cases of progression. The radiomics score included four variables. A high score indicated a poor prognosis. The radiomics score independently correlated with PFS (adjusted hazard ratio = 5.60, p = 0.003), and none of the usual response criteria independently correlated with PFS. The prognostic model based on the radiomics score had the highest concordance index (0.84; 95% CI, 0.71-0.96). CONCLUSION. Quantifying early changes in heterogeneity through a dedicated radiomics score could improve response evaluation for patients with DT undergoing chemotherapy.

Response evaluation for immunotherapy through semi-automatic software based on RECIST 1.1, irRC, and iRECIST criteria: comparison with subjective assessment.

BACKGROUND: Pseudoprogression is difficult to diagnose in patients undergoing immunotherapy. Subjective response assessment is still common in clinical practice. PURPOSE: To evaluate the differences between response evaluation criteria in solid tumors version 1.1 (RECIST 1.1), immune-related response criteria (irRC), and modified RECIST 1.1 for immunotherapy (iRECIST) through semi-automatic software, and to compare iRECIST-based response evaluation with subjective assessment. MATERIAL AND METHODS: The best overall response of each patient based on RECIST 1.1, irRC, and iRECIST was determined on CT scans through semi-automatic software and the differences between the criteria were evaluated. Criteria-based response evaluation through semi-automatic software was compared with subjective assessment on radiology report by correlating the best overall response to overall survival. RESULTS: A total of 21 patients were included (five patients with melanoma, 12 patients with non-small-cell lung cancer, and four patients with hepatocellular carcinoma). Two patients with progressive disease by RECIST 1.1 but non-progressive disease by irRC and iRECIST eventually experienced tumor response and had favorable outcomes, indicating pseudoprogression. The survival difference between patients with non-progressive disease and progressive disease was better stratified through iRECIST-based response evaluation (P = 0.078) than that through subjective assessment (P = 0.501). CONCLUSION: Pseudoprogression in immunotherapy may be captured through semi-automatic software utilizing irRC or iRECIST criteria. iRECIST-based response evaluation may provide a better survival stratification compared with subjective assessment.

Association between depth of response and survival in patients with advanced-stage non-small cell lung cancer treated with first-line chemotherapy.

BACKGROUND: A partial response according to the Response Evaluation Criteria in Solid Tumors includes a wide range of changes in tumor size. This study evaluated whether further specification of tumor reduction based on the depth of response (DpR) would provide a more precise association with outcomes for patients with non-small cell lung cancer (NSCLC) treated with first-line platinum-based chemotherapy. METHODS: A retrospective analysis was performed for the randomized phase 3 CA031 trial in patients with NSCLC treated with carboplatin in combination with nab-paclitaxel or solvent-based paclitaxel. Quartiles according to the maximum tumor reduction from the baseline were defined (quartile 1 [Q1], >0% to 25%; quartile 2 [Q2], >25% to 50%; quartile 3 [Q3], >50% to 75%; and quartile 4 [Q4], >75%) and were compared with those patients with no tumor reduction (NTR). The primary objective was to evaluate the association between DpR and overall survival (OS). RESULTS: Of the 1052 patients enrolled in the CA031 trial, 959 (91%) were evaluable, and they included 365 (38.1%) who were classified as Q1, 327 (34.1%) who were classified as Q2, 131 (13.7%) who were classified as Q3, and 34 (3.5%) who were classified as Q4; 102 had NTR (10.6%). The median OS values for patients in the NTR, Q1, Q2, Q3, and Q4 groups were 4.8, 10.4, 14.5, 19.3, and 23.5 months, respectively. The maximum DpR on treatment was an independent predictor of improved OS in comparison with patients with NTR; the hazard ratio decreased from 0.43 in Q1 to 0.16 in Q4. CONCLUSIONS: DpR was strongly associated with OS in patients with NSCLC receiving first-line platinum-based therapy. Additional studies may help to define the role of DpR in solid tumors.

Local Tumor Control and Patient Outcome Using Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: iRECIST as a Potential Substitute for Traditional Criteria.

OBJECTIVE. The purpose of this study was to investigate whether, compared with traditional criteria, the modified Response Evaluation Criteria in Solid Tumors version 1.1 for immune-based therapeutics (iRECIST) improves prediction of local tumor control and survival in patients with hepatocellular carcinoma (HCC) treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS. Fifty-one HCC lesions (mean size, 3.1 cm) treated with SBRT in 41 patients (mean age, 67 years) were retrospectively included. Each patient underwent CT or MRI before SBRT and at least once after SBRT. Best overall response was categorized using Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), iRECIST, World Health Organization (WHO) criteria, modified Response Evaluation Criteria in Solid Tumors (mRECIST), and European Association for the Study of the Liver (EASL) criteria. Lesions were then classified as local tumor control (i.e., stable disease, partial response, or complete response) or local treatment failure (i.e., progressive disease) by each tumor response criteria. Proportions of local tumor control were compared using the McNemar exact test. The 1-year overall survival was estimated using the Kaplan-Meier method. RESULTS. The median follow-up after SBRT was 21.0 months. The local tumor control rate was 94.1% (48/51) by iRECIST, 88.2% (45/51) by RECIST 1.1, 72.5% (37/51) by WHO criteria, 80.4% (41/51) by mRECIST, and 72.5% (37/51) by EASL criteria. The local tumor control rate was significantly higher according to iRECIST compared with WHO (p = 0.0010) and EASL (p = 0.0225) criteria. The 1-year survival rate for patients with local tumor control according to iRECIST (86.4%) was higher (although not statistically significant) compared with the 1-year survival rate for patients with local tumor control according to the other response criteria. CONCLUSION. iRECIST may provide more robust interpretation of HCC response after SBRT, yielding improved prediction of local tumor control and 1-year survival rates compared with traditional criteria.

Imaging-based biomarkers: Changes in the tumor interface of pancreatic ductal adenocarcinoma on computed tomography scans indicate response to cytotoxic therapy.

BACKGROUND: The assessment of pancreatic ductal adenocarcinoma (PDAC) response to therapy remains challenging. The objective of this study was to investigate whether changes in the tumor/parenchyma interface are associated with response. METHODS: Computed tomography (CT) scans before and after therapy were reviewed in 4 cohorts: cohort 1 (99 patients with stage I/II PDAC who received neoadjuvant chemoradiation and surgery); cohort 2 (86 patients with stage IV PDAC who received chemotherapy), cohort 3 (94 patients with stage I/II PDAC who received protocol-based neoadjuvant gemcitabine chemoradiation), and cohort 4 (47 patients with stage I/II PDAC who received neoadjuvant chemoradiation and were prospectively followed in a registry). The tumor/parenchyma interface was visually classified as either a type I response (the interface remained or became well defined) or a type II response (the interface became poorly defined) after therapy. Consensus (cohorts 1-3) and individual (cohort 4) visual scoring was performed. Changes in enhancement at the interface were quantified using a proprietary platform. RESULTS: In cohort 1, type I responders had a greater probability of achieving a complete or near-complete pathologic response (21% vs 0%; P = .01). For cohorts 1, 2, and 3, type I responders had significantly longer disease-free and overall survival, independent of traditional covariates of outcomes and of baseline and normalized cancer antigen 19-9 levels. In cohort 4, 2 senior radiologists achieved a κ value of 0.8, and the interface score was associated with overall survival. The quantitative method revealed high specificity and sensitivity in classifying patients as type I or type II responders (with an area under the receiver operating curve of 0.92 in cohort 1, 0.96 in cohort 2, and 0.89 in cohort 3). CONCLUSIONS: Changes at the PDAC/parenchyma interface may serve as an early predictor of response to therapy. Cancer 2018;124:1701-9. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Historical time to disease progression and progression-free survival in patients with recurrent/refractory neuroblastoma treated in the modern era on Children's Oncology Group early-phase trials.

BACKGROUND: Early-phase trials in patients with recurrent neuroblastoma historically used an objective "response" of measureable disease (Response Evaluation Criteria In Solid Tumors [RECIST], without bone/bone marrow assessment) to select agents for further study. Historical cohorts may be small and potentially biased; to the authors' knowledge, disease recurrence studies from international registries are outdated. Using a large recent cohort of patients with recurrent/refractory neuroblastoma from Children's Oncology Group (COG) modern-era early-phase trials, the authors determined outcome and quantified parameters for designing future studies. METHODS: The first early-phase COG trial enrollment (sequential) of 383 distinct patients with recurrent/refractory neuroblastoma on 23 phase 1, 3 phase 1/2, and 9 phase 2 trials (August 2002 to January 2014) was analyzed for progression-free survival (PFS), overall survival (OS), and time to disease progression (TTP). Planned frontline therapy for patients with high-risk neuroblastoma included hematopoietic stem cell transplantation (approximately two-thirds of patients underwent ≥1 hematopoietic stem cell transplantation); 13.2% of patients received dinutuximab. RESULTS: From the time of the patient's first early-phase trial enrollment (383 patients), the 1-year and 4-year PFS rates ( ± standard error) were 21% ± 2% and 6% ± 1%, respectively, whereas the 1-year and 4-year OS rates were 57% ± 3% and 20% ± 2%, respectively. The median TTP was 58 days (interquartile range, 31-183 days [350 patients]); the median follow-up was 25.3 months (33 patients were found to be without disease recurrence/progression). The median time from diagnosis to first disease recurrence/progression was 18.7 months (range, 1.4-64.8 months) (176 patients). MYCN amplification and 11q loss of heterozygosity were prognostic of worse PFS and OS (P = .003 and P<.0001, respectively, and P = .02 and P = .03, respectively) after early-phase trial enrollment. CONCLUSIONS: This recent COG cohort of patients with recurrent/refractory neuroblastoma is inclusive and representative. To the authors' knowledge, the current study is the first meta-analysis of PFS, TTP, and OS within the context of modern therapy. These results will inform the design of future phase 2 studies by providing a) historical context during the search for more effective agents; and, b) factors prognostic of PFS and OS after disease recurrence to stratify randomization. Cancer 2017;123:4914-23. © 2017 American Cancer Society.

Hepatic Parenchymal Heterogeneity as a Marker for Oxaliplatin-Induced Sinusoidal Obstruction Syndrome: Correlation With Treatment Response of Colorectal Cancer Liver Metastases.

OBJECTIVE: The objective of our study was to evaluate the influence of oxaliplatin-based chemotherapy (OBC)-induced hepatic parenchymal heterogeneity detected on contrast-enhanced CT scans on response of liver metastasis. We chose to study hepatic parenchymal heterogeneity on the basis of the assumption that hepatic parenchymal heterogeneity may indicate the presence of chemotherapy-induced sinusoidal obstruction syndrome (SOS). MATERIALS AND METHODS: For this retrospective study, 104 patients with hepatic metastases from colorectal cancer (male-female ratio, 66:38; age range, 20-80 years) who had undergone OBC and serial CT studies were consecutively registered. Two blinded imagers independently scored CT images using a 5-point scale to determine the severity of newly developed hepatic parenchymal heterogeneity after OBC. Subsequently, two radiologists evaluated tumor response to OBC using a 4-point ordinal scale. We performed generalized estimating equation (GEE) analysis using cumulative logits to account for the effect of hepatic parenchymal heterogeneity severity on the cumulative tumor response probability. RESULTS: The interobserver agreements for the severity of hepatic parenchymal heterogeneity were excellent (κ = 0.825). GEE analyses showed that the severity of post-OBC hepatic parenchymal heterogeneity, number of chemotherapy sessions, and presence of other organ metastases were significant predictors of tumor response; these three factors also showed significance in the final GEE model (p < 0.0001 for severity of hepatic parenchymal heterogeneity for both readers; p = 0.011 and 0.010 for the number of chemotherapy sessions for readers 1 and 2; p = 0.046 and 0.012 for the presence of other organ metastases for readers 1 and 2). CONCLUSION: Hepatic parenchymal heterogeneity detected on contrast-enhanced CT of patients with hepatic metastases from colorectal cancer who have undergone OBC may indicate the presence of SOS, and the more severe the SOS, the worse the tumor response of hepatic metastasis to oxaliplatin is expected to be.

Radiology Reports With Hyperlinks Improve Target Lesion Selection and Measurement Concordance in Cancer Trials.

OBJECTIVE: Radiology reports often lack the measurements of target lesions that are needed for oncology clinical trials. When available, the measurements in the radiology reports often do not match those in the records used to calculate therapeutic response. This study assessed the clinical value of hyperlinked tumor measurements in multimedia-enhanced radiology reports in the PACS and the inclusion of a radiologist assistant in the process of assessing tumor burden. MATERIALS AND METHODS: We assessed 489 target lesions in 232 CT examinations of 71 patients with metastatic genitourinary cancer enrolled in two therapeutic trials. We analyzed target lesion selection and measurement concordance between oncology records (used to calculate therapeutic response) and two types of radiology reports in the PACS: multimedia-enhanced radiology reports and text-only reports. For statistical tests, we used the Wilcoxon signed rank, Wilcoxon rank sum test, and Fisher method to combine p values from the paired and unpaired results. The Fisher exact test was used to compare overall measurement concordance. RESULTS: Concordance on target lesion selection was greater for multimedia-enhanced radiology reports (78%) than the text-only reports (52%) (p = 0.0050). There was also improved overall measurement concordance with the multimedia-enhanced radiology reports (68%) compared with the text-only reports (38%) (p < 0.0001). CONCLUSION: Compared with text-only reports, hyperlinked multimedia-enhanced radiology reports improved concordance of target lesion selection and measurement with the measurements used to calculate therapeutic response.

RECIST 1.1 compared with RECIST 1.0 in patients with advanced renal cell carcinoma receiving vascular endothelial growth factor-targeted therapy.

OBJECTIVE. Response Evaluation Criteria in Solid Tumors (RECIST) is the most widely accepted method to objectively assess response to therapy in renal cell carcinoma (RCC) treated with vascular endothelial growth factor (VEGF)-targeted therapy. Both RECIST 1.0 and 1.1 have been used to assess response to VEGF-targeted therapies; however, systematic comparisons are lacking. MATERIALS AND METHODS. Sixty-two patients with metastatic RCC treated with VEGF-targeted therapies were retrospectively studied. Tumor measurements and response assessment according to RECIST 1.1 and RECIST 1.0 were compared, including the number of target lesions, baseline measurements, response at each follow-up, best overall response, and time to progression (TTP). Morphologic changes and new enhancement were also assessed over the course of treatment, and TTP was evaluated using morphologic change criteria in combination with RECIST 1.1. RESULTS. The number of target lesions according to RECIST 1.1 was significantly fewer than by RECIST 1.0 (median, 2 vs 4; p < 0.0001). At first imaging follow-up, the percentage change of the sums of the diameter measurements by RECIST 1.1 and RECIST 1.0 were highly concordant (R = 0.857; mean shrinkage, 12.1% by RECIST 1.1 vs 10.8% by RECIST 1.0). Best response assessment was highly concordant between the two criteria (weighted κ = 0.819). There was no evidence of a difference in TTP by the two criteria, with a median TTP of 8.9 months (95% CI for the median, 5.5-13.9) by RECIST 1.1 and 8.9 months (95% CI for the median, 5.8-13.6) by RECIST 1.0. The median TTP by RECIST 1.1 alone was 8.9 months compared with 5.6 months for RECIST 1.1 and morphologic changes combined. CONCLUSION. RECIST 1.1 and RECIST 1.0 response assessments were overall highly concordant in patients with RCC treated with VEGF-targeted therapy, with fewer target lesions according to RECIST 1.1 but no difference in TTP.

Intraobserver and interobserver variability in computed tomography size and attenuation measurements in patients with renal cell carcinoma receiving antiangiogenic therapy: implications for alternative response criteria.

BACKGROUND: Alternative response criteria have been proposed in patients with metastatic renal cell carcinoma (mRCC) who are receiving vascular endothelial growth factor (VEGF)-targeted therapy, including 10% tumor shrinkage as an indicator of response/outcome. However, to the authors' knowledge, intraobserver and interobserver measurement variability have not been defined in this setting. The objective of the current study was to determine intraobserver and interobserver agreement of computed tomography (CT) size and attenuation measurements to establish reproducible response indicators. METHODS: Seventy-one patients with mRCC with 179 target lesions were enrolled in phase 2 and phase 3 trials of VEGF-targeted therapies and retrospectively studied with Institutional Review Board approval. Two radiologists independently measured the long axis diameter and mean attenuation of target lesions at baseline and on follow-up CT. Concordance correlation coefficients and Bland-Altman plots were used to assess intraobserver and interobserver agreement. RESULTS: High concordance correlation coefficients (range, 0.8602-0.9984) were observed in all types of measurements. The 95% limits of agreement for the percentage change of the sum longest diameter was -7.30% to 7.86% for intraobserver variability, indicating that 10% tumor shrinkage represents a true change in tumor size when measured by a single observer. The 95% limits of interobserver variability were -16.3% to 15.4%. On multivariate analysis, the location of the lesion was found to significantly contribute to interobserver variability (P = .048). The 95% limits of intraobserver agreement for the percentage change in CT attenuation were -18.34% to 16.7%. CONCLUSIONS: In patients with mRCC who are treated with VEGF inhibitors, 10% tumor shrinkage is a reproducible radiologic response indicator when baseline and follow-up studies are measured by a single radiologist. Lesion location contributes significantly to measurement variability and should be considered when selecting target lesions.

Imaging response to immune checkpoint inhibitors in patients with advanced melanoma: a retrospective observational cohort study.

Background: The association between objective imaging response and first line immune checkpoint inhibitor (ICI) therapy regimes in advanced melanoma remains uncharacterized in routine practice. Methods: We conducted a multi-center retrospective cohort analysis of advanced melanoma patients receiving first line ICI therapy from August 2013-May 2020 in Alberta, Canada. The primary outcome was likelihood of RECIST v1.1 assessed objective imaging response between patients receiving anti-programmed cell death protein 1 (anti-PD1) monotherapy and those receiving combination ipilimumab-nivolumab. Secondary outcomes were identification of baseline characteristics associated with non-response and the association of imaging response with overall survival (OS) and time to next treatment (TTNT). Results: 198 patients were included, 41/198 (20.7%) had complete response, 86/198 (43.4%) had partial response, 23/198 (11.6%) had stable disease, and 48/198 (24.2%) had progressive disease. Median OS was not reached (NR) (95% CI 49.0-NR) months for complete responders, NR (95%CI 52.9-NR) months for partial responders, 33.7 (95%CI 15.8-NR) months for stable disease, and 6.4 (95%CI 5.2-10.1) months for progressive disease (log-rank p<0.001). Likelihood of objective imaging response remained similar between anti-PD1 monotherapy and ipilimumab-nivolumab groups (OR 1.95 95%CI 0.85-4.63, p=0.121). Elevated LDH level (OR 0.46; 95%CI 0.21-0.98, p=0.043), mucosal primary site (OR 0.14; 95%CI 0.03-0.48, p=0.003), and BRAF V600E mutation status (OR 0.31; 95%CI 0.13-0.72, p=0.007) were associated with decreased likelihood of response. Conclusion: No significant difference in likelihood of imaging response between anti-PD1 monotherapy and combination ipilimumab-nivolumab was observed. Elevated LDH level, mucosal primary site, and BRAF V600E mutation status were associated with decreased likelihood of response. Given that pivotal clinical trials of ipilimumab-nivolumab did not formally compare ipilimumab-nivolumab with nivolumab monotherapy, this work adds context to differences in outcomes when these agents are used. These results may inform treatment selection, and aid in counseling of patients treated with first-line ICI therapy in routine clinical practice settings.

Evaluation of Response to Atezolizumab Plus Bevacizumab in Patients with Advanced Hepatocellular Carcinoma Using the Combination of Response Evaluation Criteria in Solid Tumors and Alpha-Fetoprotein.

Atezolizumab plus bevacizumab combination therapy (Atezo + Beva) is currently positioned as the first-line therapy for unresectable hepatocellular carcinoma (u-HCC). It may be difficult to decide whether to continue this treatment if radiological response is assessed as stable disease (SD). Therefore, the relationship between radiological response and prognosis was analyzed. A total of 109 patients with u-HCC and Child-Pugh Score of 5-7 received this treatment. Radiological response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST at the first and second evaluations. Of SD patients (n = 71) at the first RECIST evaluation, partial response, SD, and progressive disease (PD) were seen in 10, 55, and 6 patients, respectively, at the second evaluation. On multivariate analysis, in patients with SD at the first RECIST evaluation, a 25% or greater increase in the alpha-fetoprotein (AFP) value from initiation of treatment (odds ratio, 7.38; p = 0.037) was the independent factor for PD at the second evaluation. In patients with SD (n = 59) at the second RECIST evaluation, decreased AFP from initiation of treatment (hazard ratio, 0.46; p = 0.022) was the independent factor related to progression-free survival on multivariate analysis. AFP trends could help decide the Atezo + Beva treatment strategy.

Analysis of Survival and Response to Lenvatinib in Unresectable Hepatocellular Carcinoma.

The association between radiological response and overall survival (OS) was retrospectively evaluated in patients treated with lenvatinib as a first-line systemic treatment for unresectable hepatocellular carcinoma. A total of 182 patients with Child-Pugh class A liver function and an Eastern Cooperative Oncology Group performance status of zero or one were enrolled. Radiological evaluation was performed using Response Evaluation Criteria in Solid Tumors (RECIST) and modified Response Evaluation Criteria in Solid Tumors (mRECIST). Initial radiological evaluation confirmed significant stratification of OS by efficacy judgment with both RECIST and mRECIST, and that initial radiological response was an independent prognostic factor for OS on multivariate analysis. Furthermore, in patients with stable disease (SD) at initial evaluation, macrovascular invasion at the initial evaluation on RECIST and modified albumin-bilirubin grade at initial evaluation on mRECIST were independent predictors of OS on multivariate analysis. In conclusion, if objective response is obtained at the initial evaluation, continuation of treatment appears desirable because prolonged OS can be expected; but, if SD is obtained at the initial evaluation, one should determine whether to continue or switch to the next treatment, with careful consideration of factors related to the tumor and hepatic reserve at the initial evaluation.

Exploring the Interobserver Agreement in Computer-Aided Radiologic Tumor Measurement and Evaluation of Tumor Response.

The accurate, objective, and reproducible evaluation of tumor response to therapy is indispensable in clinical trials. This study aimed at investigating the reliability and reproducibility of a computer-aided contouring (CAC) tool in tumor measurements and its impact on evaluation of tumor response in terms of RECIST 1.1 criteria. A total of 200 cancer patients were retrospectively collected in this study, which were randomly divided into two sets of 100 patients for experiential learning and testing. A total of 744 target lesions were identified by a senior radiologist in distinctive body parts, of which 278 lesions were in data set 1 (learning set) and 466 lesions were in data set 2 (testing set). Five image analysts were respectively instructed to measure lesion diameter using manual and CAC tools in data set 1 and subsequently tested in data set 2. The interobserver variability of tumor measurements was validated by using the coefficient of variance (CV), the Pearson correlation coefficient (PCC), and the interobserver correlation coefficient (ICC). We verified that the mean CV of manual measurement remained constant between the learning and testing data sets (0.33 vs. 0.32, p = 0.490), whereas it decreased for the CAC measurements after learning (0.24 vs. 0.19, p < 0.001). The interobserver measurements with good agreement (CV < 0.20) were 29.9% (manual) vs. 49.0% (CAC) in the learning set (p < 0.001) and 30.9% (manual) vs. 64.4% (CAC) in the testing set (p < 0.001). The mean PCCs were 0.56 ± 0.11 mm (manual) vs. 0.69 ± 0.10 mm (CAC) in the learning set (p = 0.013) and 0.73 ± 0.07 mm (manual) vs. 0.84 ± 0.03 mm (CAC) in the testing set (p < 0.001). ICCs were 0.633 (manual) vs. 0.698 (CAC) in the learning set (p < 0.001) and 0.716 (manual) vs. 0.824 (CAC) in the testing set (p < 0.001). The Fleiss' kappa analysis revealed that the overall agreement was 58.7% (manual) vs. 58.9% (CAC) in the learning set and 62.9% (manual) vs. 74.5% (CAC) in the testing set. The 80% agreement of tumor response evaluation was 55.0% (manual) vs. 66.0% in the learning set and 60.6% (manual) vs. 79.7% (CAC) in the testing set. In conclusion, CAC can reduce the interobserver variability of radiological tumor measurements and thus improve the agreement of imaging evaluation of tumor response.

Early Tumor Shrinkage as a Predictive Factor for Outcomes in Hepatocellular Carcinoma Patients Treated with Lenvatinib: A Multicenter Analysis.

We investigated the association between early tumor shrinkage (ETS) and treatment outcome in patients with hepatocellular carcinoma treated with lenvatinib (LEN). A retrospective analysis was performed in 104 patients. ETS was defined as tumor shrinkage at the first evaluation in the sum of target lesions' longest diameters from baseline according to the Response Evaluation Criteria in Solid Tumors (RECIST). The median overall survival (OS) was not reached, whereas the median progression-free survival (PFS) was 5.0 months. The receiver operating characteristic curve analysis in differentiating long-term responders (PFS ≥ 5.0 months) from short-term responders (PFS < 5.0 months) revealed an ETS cut-off value of 10%. ETS ≥ 10% was significantly correlated with better PFS and OS compared with ETS < 10%. Additionally, ETS ≥ 10% showed a better discrimination ability on prognosis compared with modified RECIST-based objective response at the first evaluation. Multivariate analysis confirmed ETS ≥ 10% as an independent predictor of better OS, as well as a Child-Pugh score of 5 and macrovascular invasion. In conclusion, ETS ≥ 10% was strongly associated with outcome in patients treated with LEN. This biomarker could allow earlier assessment of the treatment response and guide treatment decision-making for HCC.

Imaging of tumour response to immunotherapy.

A wide range of cancer immunotherapy approaches has been developed including non-specific immune-stimulants such as cytokines, cancer vaccines, immune checkpoint inhibitors (ICIs), and adoptive T cell therapy. Among them, ICIs are the most commonly used and intensively studied. Since 2011, these drugs have received marketing authorisation for melanoma, lung, bladder, renal, and head and neck cancers, with remarkable and long-lasting treatment response in some patients. The novel mechanism of action of ICIs, with immune and T cell activation, leads to unusual patterns of response on imaging, with the advent of so-called pseudoprogression being more pronounced and frequently observed when compared to other anticancer therapies. Pseudoprogression, described in about 2-10% of patients treated with ICIs, corresponds to an increase of tumour burden and/or the appearance of new lesions due to infiltration by activated T cells before the disease responds to therapy. To overcome the limitation of response evaluation criteria in solid tumors (RECIST) to assess these specific changes, new imaging criteria-so-called immune-related response criteria and then immune-related RECIST (irRECIST)-were proposed. The major modification involved the inclusion of the measurements of new target lesions into disease assessments and the need for a 4-week re-assessment to confirm or not confirm progression. The RECIST working group introduced the new concept of "unconfirmed progression", into the irRECIST. This paper reviews current immunotherapeutic approaches and summarises radiologic criteria to evaluate new patterns of response to immunotherapy. Furthermore, imaging features of immunotherapy-related adverse events and available predictive biomarkers of response are presented.

Modification of the tumor response threshold in patients of advanced non-small cell lung cancer treated with chemotherapy plus targeted agents: a pooled study from five clinical trials in one institution.

BACKGROUND: Chemotherapy with targeted therapy is a promising therapeutic option for advanced non-small cell lung cancer (NSCLC) patients. Response Evaluation Criteria in Solid Tumors (RECIST) criteria were used in tumor response evaluation. We assumed an optimal threshold for this therapeutic setting and tried to seek a new tumor shrinkage cutoff with the data from five clinical trials in one institution. METHODS: The X-tile program was used to identify the optimal cut-off value of tumor shrinkage. PFS and OS were compared in the current study. Kaplan-Meier method was used to describe PFS and OS. 95% CI was calculated for PFS and OS outcomes to assess the treatment efficacy. A P value of less than 0.05 was considered statistically significant. SPSS 23.0 was used for all statistical analysis. RESULTS: X-tile analysis yielded -10% in the ∆SLD of the target lesions as the optimal threshold for response/non-response. The 10% tumor shrinkage could discriminate responders from non-responders in PFS (10.1 vs. 2.50 months, P=0.0007) and OS (23.00 vs. 7.66 months, P<0.0001). Univariate and multivariable analysis showed that 10% tumor shrinkage was a valid prognostic factor for PFS (P=0.018) and OS outcome (P<0.0001). CONCLUSIONS: A 10.0% tumor shrinkage in the SLD indicated an indicative efficacy evaluation threshold for NSCLC patients treated with chemotherapy plus targeted agents.

Maximum diameter versus volumetric assessment for the response evaluation of vestibular schwannomas receiving stereotactic radiotherapy.

PURPOSE: To explore the feasibility of maximum diameter as a response assessment method for vestibular schwannomas (VS) after stereotactic radiosurgery or fractionated stereotactic radiotherapy (RT), we analyzed the concordance of RT responses between maximum diameters and volumetric measurements. Materials and. METHODS: Forty-two patients receiving curative stereotactic radiosurgery or fractionated stereotactic RT for VS were analyzed retrospectively. Twelve patients were excluded: 4 did not receive follow-up magnetic resonance imaging (MRI) scans and 8 had initial MRI scans with a slice thickness >3 mm. The maximum diameter, tumor volume (TV), and enhanced tumor volume (ETV) were measured in each MRI study. The percent change after RT was evaluated according to the measurement methods and their concordances were calculated with the Pearson correlation. The response classifications were determined by the assessment modalities, and their agreement was analyzed with Cohen kappa statistics. RESULTS: Median follow-up was 31.0 months (range, 3.5 to 86.5 months), and 90 follow-up MRI studies were analyzed. The percent change of maximum diameter correlated strongly with TV and ETV (r(p) = 0.85, 0.63, p = 0.000, respectively). Concordance of responses between the Response Evaluation Criteria in Solid Tumors (RECIST) using the maximum diameters and either TV or ETV were moderate (kappa = 0.58; 95% confidence interval, 0.32-0.85) or fair (kappa = 0.32; 95% confidence interval, 0.05-0.59), respectively. Conclusions: The percent changes in maximum diameter and the responses in RECIST were significantly concordant with those in the volumetric measurements. Therefore, the maximum diameters can be used for the response evaluation of VS following stereotactic RT.