Response Assessment In Patients Research Articles

Machine learning–based response assessment in patients with rectal cancer after neoadjuvant chemoradiotherapy: radiomics analysis for assessing tumor regression grade using T2-weighted magnetic resonance images

PurposeThis study aimed to assess tumor regression grade (TRG) in patients with rectal cancer after neoadjuvant chemoradiotherapy (NCRT) through a machine learning–based radiomics analysis using baseline T2-weighted magnetic resonance (MR) images.Materials and methodsIn total, 148 patients with locally advanced rectal cancer(T2-4 or N+) who underwent MR imaging at baseline and after chemoradiotherapy between January 2010 and May 2021 were included. A region of interest for each tumor mass was drawn by a radiologist on oblique axial T2-weighted images, and main features were selected using principal component analysis after dimension reduction among 116 radiomics and three clinical features. Among eight learning models that were used for prediction model development, the model showing best performance was selected. Treatment responses were classified as either good or poor based on the MR-assessed TRG (mrTRG) and pathologic TRG (pTRG). The model performance was assessed using the area under the receiver operating curve (AUROC) to classify the response group.ResultsApproximately 49% of the patients were in the good response (GR) group based on mrTRG (73/148) and 26.9% based on pTRG (28/104). The AUCs of clinical data, radiomics models, and combined radiomics with clinical data model for predicting mrTRG were 0.80 (95% confidence interval [CI] 0.73, 0.87), 0.74 (95% CI 0.66, 0.81), and 0.75(95% CI 0.68, 0.82), and those for predicting pTRG was 0.62 (95% CI 0.52, 0.71), 0.74 (95% CI 0.65, 0.82), and 0.79 (95% CI 0.71, 0.87).ConclusionRadiomics combined with clinical data model using baseline T2-weighted MR images demonstrated feasible diagnostic performance in predicting both MR-assessed and pathologic treatment response in patients with rectal cancer after NCRT.

The quality of life after keratinized mucosa augmentation around dental implants using xenogenic collagen matrix with or without stent.

The substitution of missing teeth with implants is a dependable and anticipated therapeutic approach. Despite numerous studies affirming long-term success rates, there exists a spectrum of potential biological and aesthetic complications. The primary objective of this study was to assess patient responses subsequent to surgical interventions, with a specific emphasis on the utilization of xenogenic collagen matrix (XCM), both with and without the application of a stent secured over healing abutments, in the context of keratinized gingival mucosa augmentation. The principal aim was to evaluate and draw comparisons between the clinical outcomes resulting from these two procedural approaches, with a particular focus on critical parameters encompassing post-operative complications, patient comfort, and the overall efficacy in achieving successful keratinized tissue augmentation. Sixty patients were selected for this study. The patients were divided into three groups: A, B, and a control group, with each group comprising 20 participants. We used XCM in experimental group A, XCM covered with surgical stent in experimental group B, and free gingival graft (FGG) in the control group. After the surgical procedure, patients were required to complete a visual analogue scale (VAS) questionnaire for post-operative complications, and a quality of life (QOL) questionnaire on days 1, 3, and 7. Patients in the experimental groups A and B demonstrated markedly improved outcomes when compared with the control group. Assessments conducted on days 1, 3, and 7 demonstrated diminished levels of pain, bleeding, and swelling in both experimental groups, with experimental group B showing the least discomfort. The incorporation of XCM, either with or without stents, was associated with a reduction in analgesic consumption, underscoring its favorable influence on post-operative comfort, notwithstanding the exception of halitosis in experimental group B. Using XCM with or without a stent for keratinized tissue augmentation has better post-operative outcomes associated with reduced swelling, bleeding, and pain based on the QOL survey. This study provides data to support the clinical application of XCM and stents.

Remote Symptom Monitoring Using Patient-Reported Outcomes in Patients With Chronic Kidney Disease: Process Evaluation of a Randomized Controlled Trial.

In Denmark, outpatient follow-up for patients with chronic kidney disease (CKD) is changing from in-hospital visits toward more remote health care delivery. The nonuse of remote patient-reported outcomes (PROs) is a well-known challenge, and it can be difficult to explain which mechanisms of interventions influence the outcome. Process evaluation may, therefore, be used to answer important questions on how and why interventions work, aiming to enhance the implications for clinical practice. This study aimed to provide insight into the intervention process by evaluating (1) the representativity of the study population, (2) patient and physician use patterns, (3) patient adherence to the intervention, and (4) clinical engagement. A process evaluation determining the reach, dose, fidelity, and clinical engagement was carried out, alongside a multicenter randomized controlled trial (RCT). We developed and implemented an intervention using PRO measures to monitor outpatients remotely. Data were collected for the PRO intervention arms in the RCT from 4 sources: (1) PRO data from the participants to determine personal factors, (2) the web-based PRO system to identify key usage intervention patterns, (3) medical records to identify clinical factors relating to the use of the intervention, and (4) semistructured interviews conducted with involved physicians. Of the 320 patients invited, 152 (47.5%) accepted to participate. The study population reflected the target population. The mean adherence rate to the PRO intervention arms was 82% (95% CI 76-87). The questionnaire response rate was 539/544 (99.1%). A minority of 13 (12.9%) of 101 patients needed assistance to complete study procedures. Physicians assessed 477/539 (88.5%) of the questionnaires. Contact was established in 417/539 (77.4%) of the cases, and 122/539 (22.6%) of the patients did not have contact. Physicians initiated 288/417 (69.1%) and patients requested 129/417 (30.9%) of all the contacts. The primary causes of contact were clinical data (242/417, 58%), PRO data (92/417, 22.1%), and medication concerns and precautionary reasons (83/417, 19.9%). Physicians found the use of PRO measures in remote follow-up beneficial for assessing the patient's health. The inclusion of self-reported clinical data in the questionnaire motivated physicians to assess patient responses. However, some barriers were emphasized, such as loss of a personal relationship with the patient and the risk of missing important symptoms in the absence of a face-to-face assessment. This study demonstrates the importance and practical use of remote monitoring among patients with CKD. Overall, the intervention was implemented as intended. We observed high patient adherence rates, and the physicians managed most questionnaires. Some physicians worried that distance from the patients made it unfeasible to use their "clinical glance," posing a potential risk of overlooking crucial patients' symptoms. These findings underscore key considerations for the implementation of remote follow-up. Introducing a hybrid approach combining remote and face-to-face consultations may address these concerns. ClinicalTrials.gov NCT03847766; https://clinicaltrials.gov/study/NCT03847766.

Abstract 3759: First clinical evidence of the tissue nanomechanical signature as a novel diagnostic and prognostic tool in patients with non-small-cell lung cancer

Abstract Introduction: Complex structural remodelling of cells and extracellular matrix during cancer initiation and progression elicit substantial biomechanical alterations, which can be measured by Atomic Force Microscopy (AFM) at the nanoscale level. Clinical and translational evidence indicates that tissue nanomechanical signature (NS) can be a useful tool for rapid cancer diagnosis, and assessment of cancer aggressiveness. We demonstrated that the AFM-based Automated and Reliable Tissue Diagnostics (ARTIDIS) platform represents a valid method for rapid diagnosis, prognosis, and treatment response assessment in patients with breast cancer. Here we aimed to use this platform to examine tumour biopsies from non-small cell lung cancer (NSCLC) patients for the first time. Methods: This is an ongoing, single center study at the Hospital Clinic of Barcelona and University of Barcelona (UHB) Spain, aiming to enroll 75 patients by January 2024 in the first phase, followed by 200 patients in the expansion phase. To date, 54 matching tumor and non-tumor fresh tissue biopsies were taken by experienced pathologists from fresh surgical resection specimens from 27 patients with previously diagnosed NSCLC. Tissue biopsies were measured with the ARTIDIS device in a blinded manner, without knowing the malignancy status of the biopsy. Routine clinico-pathologic parameters have been collected. The multiparametric nanomechanical signature has been analyzed in an automated manner using the proprietary AI-based ARTIDISNET software platform together with available clinico-pathologic parameters. Results: In total, the NSCLC tissue samples included 16 squamous cell carcinoma (SCC), 6 Adenocarcinoma (ADC), 1 large cell carcinoma (LCC) and 4 other histological subtypes. Non-tumor tissues exhibited significantly varied composition, including normal lung parenchyma, bronchial tissues, fibrosis and inflammatory changes. Among the 27 patients, 5 patients developed distant progression within 12 months after ARTIDIS measurements. Results analysis showed that the ARTIDIS NS can reliably differentiate malignant NSCLC lesions from non-tumor lung tissue, with a sensitivity of 0.84, specificity of 0.81, positive predictive value (PPV) of 0.79, negative predictive value (NPV) of 0.86 and accuracy of 0.82. In addition, the ARTIDIS NS can differentiate patients with and without distant progression with a sensitivity of 0.62, specificity of 0.81, PPV of 0.42, NPV of 0.90 and accuracy of 0.77. Conclusions: Here we demonstrated first clinical evidence of the ARTIDIS tissue NS as a novel diagnostic and prognostic tool in patients with NSCLC. This study aims to establish the diagnostic, prognostic, and predictive NS in patients NSCLC. In addition to local expansion at the UHB, study results will be further validated in ARTIDIS clinical program at MD Anderson Cancer Centre, USA. Citation Format: Jordi Alcaraz, Héctor Sanz-Fraile, Elba Marin, Paula Gausa Busquets, Kate Neal, Marselina Arshakyan, Marc Rico, Marc Boada, David Sanchez, Reinier Oropesa Nunez, Gitika Srivastava, Ahmed Jizawi, Sara Nizzero, Tobias Appenzeller, Mariam Gachechiladze, Marko Loparic, Marija Plodinec, Noemi Reguart. First clinical evidence of the tissue nanomechanical signature as a novel diagnostic and prognostic tool in patients with non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3759.

CT-based screening of sarcopenia and its role in cachexia syndrome in pancreatic cancer.

Since computed tomography (CT) is a part of standard diagnostic protocol in pancreatic ductal adenocarcinoma (PDAC), we have evaluated the value of CT for sarcopenia screening in patients with PDAC, intending to expand the diagnostic value of tomographic studies. In our study, we included 177 patients with available CT images. Two groups were formed: Group 1 consisted of 117 patients with PDAC in various locations and stages and Group 2, or the control group, consisted of 60 "nominally healthy" patients with other somatic non-oncological diseases. The body mass index (BMI) was defined as a ratio of patient's weight to the square of their height (kg/m2). CT-based body composition analysis was performed using commercially available software with evaluation of sarcopenia using skeletal muscle index (SMI, cm2/m2). Based on the SMI values, sarcopenia was found in 67.5% of patients (79 out of 117) in the first patient group. It was found more frequently in males (42 out of 56; 75%) than in females (37 out of 61; 60.6%). Additionally, we observed a decrease in muscle mass (hidden sarcopenia) in 79.7% in patients with a normal BMI. Even in overweight patients, sarcopenia was found in 50% (sarcopenic obesity). In patients with reduced BMI sarcopenia was found in all cases (100%). Statistically significant difference of SMI between two groups was revealed for both sexes (p = 0,0001), with no significant difference between groups in BMI. BMI is an inaccurate value for the assessment of body composition as it does not reflect in the details the human body structure. As SMI may correlate with the prognosis, decreased muscle mass- especially "hidden" sarcopenia or sarcopenic obesity- should be reported. The use of CT-based evaluation of sarcopenia and sarcopenic obesity will allow for a better treatment response assessment in patients with cancer cachexia.

Identification and validation of a signature based on myofibroblastic cancer-associated fibroblast marker genes for predicting prognosis, immune infiltration, and therapeutic response in bladder cancer.

Myofibroblastic cancer-associated fibroblasts (myCAFs) are important components of the tumor microenvironment closely associated with tumor stromal remodeling and immunosuppression. This study aimed to explore myCAFs marker gene biomarkers for clinical diagnosis and therapy for patients with bladder cancer (BC). BC single-cell RNA sequencing (scRNA-seq) data were obtained from the National Center for Biotechnology Information Sequence Read Archive. Transcriptome and clinical data were downloaded from The Cancer Genome Atlas and the Gene Expression Omnibus databases. Subsequently, univariate Cox and LASSO (Least Absolute Shrinkage and Selection Operator regression) regression analyses were performed to construct a prognostic signature. Immune cell activity was estimated using single-sample gene set enrichment analysis whilst the TIDE (tumor immune dysfunction and exclusion) method was employed to assess patient response to immunotherapy. The chemotherapy response of patients with BC was evaluated using genomics of drug sensitivity in cancer. Furthermore, Immunohistochemistry was used to verify the correlation between MAP1B expression and immunotherapy efficacy. The scRNA-seq data were analyzed to identify myCAFs marker genes. Combined with bulk RNA-sequencing data, we constructed a two-gene (COL6A1 and MAP1B) risk signature. In patients with BC, the signature demonstrated outstanding prognostic value, immune infiltration, and immunotherapy response. This signature served as a crucial guide for the selection of anti-tumor chemotherapy medications. Additionally, immunohistochemistry confirmed that MAP1B expression was significantly correlated with immunotherapy efficacy. Our findings revealed a typical prognostic signature based on myCAF marker genes, which offers patients with BC a novel treatment target alongside theoretical justification.

Treatment Response Assessment in Multiple Myeloma: Histogram Analysis of Total Tumor Apparent Diffusion Coefficient based on Whole‐body Diffusion‐weighted MR Imaging

BackgroundThe International Myeloma Working Group (IMWG) consensus criteria for response assessment in multiple myeloma (MM) has methodological limitations. Whole‐body diffusion‐weighted imaging (DWI) with apparent diffusion coefficient (ADC) histogram analysis may be complementary to response assessment of MM.PurposeTo explore the role of histogram analysis of the ADC based on the total tumor volume (ttADC) in response assessment in patients with newly diagnosed MM (NDMM).Study TypeRetrospective.PopulationThirty‐six patients with NDMM.Field Strength/Sequence3.0T/single‐shot DWI echo planar imaging (EPI) sequence with an integrated slice‐by‐slice shimming (iShim) technique.AssessmentBaseline (median: 1 day before treatment) and post‐treatment (median: five cycles of therapy) whole‐body DWI were analyzed. A region of interest (ROI) containing lesions on every section of baseline image was drawn to derive the per‐patient total tumor data. Post‐treatment image analysis was based on the same ROI as the corresponding baseline. Histogram metrics were extracted from both ROIs. Patients were categorized into the very good partial response or better (VGPR+) group and the less than VGPR group per the IMWG response criteria for response assessment. Progression‐free survival (PFS) was also calculated.Statistical TestsMann–Whitney test and Fisher's exact or Chi‐squared tests, Receiver operating characteristic (ROC) analysis and DeLong test, Kaplan–Meier analysis and Cox proportional hazards model. A two‐tailed P‐value <0.05 was considered statistically significant.ResultsThirty patients were categorized into the VGPR+ group and six into the less than VGPR group. The ttADC histogram changes between post‐treatment and baseline metrics (ΔttADC) revealed significant differences in all percentile values between the VGPR+ and less than VGPR groups. For distinguishing VGPR+, ΔttADC_5th percentile had the largest area under the curve (AUC) (0.950, 95% CI 0.821–0.995). Patients with lower ΔttADC_5th percentile values (cutoff point, 188.193) showed significantly longer PFS (HR = 34.911, 95% CI 6.392–190.677).Data ConclusionttADC histogram may facilitate response assessment in patients with NDMM.Level of Evidence3Technical EfficacyStage 4

Volumetric analysis: Rethinking brain metastases response assessment.

The Response Assessment in Neuro-Oncology for Brain Metastases (RANO-BM) criteria are the gold standard for assessing brain metastases (BMs) treatment response. However, they are limited by their reliance on 1D, despite the routine use of high-resolution T1-weighted MRI scans for BMs, which allows for 3D measurements. Our study aimed to investigate whether volumetric measurements could improve the response assessment in patients with BMs. We retrospectively evaluated a dataset comprising 783 BMs and analyzed the response of 185 of them from 132 patients who underwent stereotactic radiotherapy between 2007 and 2021 at 5 hospitals. We used T1-weighted MRIs to compute the volume of the lesions. For the volumetric criteria, progressive disease was defined as at least a 30% increase in volume, and partial response was characterized by a 20% volume reduction. Our study showed that the proposed volumetric criteria outperformed the RANO-BM criteria in several aspects: (1) Evaluating every lesion, while RANO-BM failed to evaluate 9.2% of them. (2) Classifying response effectively in 140 lesions, compared to only 72 lesions classified by RANO-BM. (3) Identifying BM recurrences a median of 3.3 months earlier than RANO-BM criteria. Our study demonstrates the superiority of volumetric criteria in improving the response assessment of BMs compared to the RANO-BM criteria. Our proposed criteria allow for evaluation of every lesion, regardless of its size or shape, better classification, and enable earlier identification of progressive disease. Volumetric criteria provide a standardized, reliable, and objective tool for assessing treatment response.

Improvement in Iron Burden in Patients with Transfusion-Dependent β-Thalassemia (TDT) Treated with Betibeglogene Autotemcel (Beti-cel) Gene Therapy: Up to 9 Years of Follow-up

Introduction: Beti-cel is an approved, one-time gene therapy treatment for adult and pediatric patients with TDT. Beti-cel consists of autologous hematopoietic stem and progenitor cells transduced with the BB305 lentiviral vector encoding a modified β-globin gene (β A-T87Q), which produces functional hemoglobin (Hb) and addresses the underlying genetic cause of TDT. While transfusion independence (TI) remains a critical component for assessing patient response to gene therapy, other measures, including markers of iron overload, are important for evaluating the impact of therapy and management of disease burden over time. Previously, we demonstrated that iron markers stabilized in patients who achieved TI and stopped chelation therapy. Here, we report iron management outcomes in patients who completed either a phase 1/2 or phase 3 beti-cel parent study and subsequently enrolled in the long-term follow-up study. Methods: Patients with TDT who completed a parent beti-cel study (phase 1/2 studies: HGB-204 [NCT01745120]; HGB-205 [NCT02151526]; phase 3 studies: HGB-207 [NCT02906202]; HGB-212 [NCT03207009]) could enroll in a long-term study (LTF-303 [NCT02633943]) for up to an additional 13 years of follow-up. In these studies, TI was defined as a weighted average Hb ≥9 g/dL without packed red blood cell transfusions for ≥12 months. Iron removal therapy was at the discretion of the treating physician. Liver and cardiac magnetic resonance imaging evaluated liver iron concentration (LIC) and cardiac T2*; serum ferritin and transferrin receptor (TfR) were assessed at regular intervals according to protocol. Results:As of January 30, 2023, 63 patients received beti-cel; median (range) follow-up was 60.1 (23.8-109.5) months. In phase 3 studies, 37/41 (90%) patients achieved TI and maintained TI through the last follow-up, which was 5+ years for 10 patients ( Figure 1). In phase 1/2 studies, 15/22 (68%) patients achieved TI; 14 of these patients maintained TI through the last follow-up, which was up to 9 years. One patient no longer meets protocol-defined TI as a result of Hb level <9g/dL at year 6 due to acute health events unrelated to β-thalassemia, which were not attributed to loss of beti-cel treatment effect. In total, 51 patients across phase 1/2 and 3 studies achieved and maintained TI through last follow-up with 35/51 (69%) patients off chelation. Thirty of 51 patients had an LIC measurement at month 48. Of these 30 patients, 21 had an LIC <5 mg/g at month 48 post infusion. Among these 21 patients, 5 never restarted chelation after infusion (2 received phlebotomy only), 11 restarted chelation and then were able to discontinue after iron stores normalized (1 also received phlebotomy), and 5 continue to receive chelation (none had phlebotomy). The other 9 patients who had an LIC measurement at month 48 had an iron burden ≥5 mg/g. All 9 of these patients restarted chelation; 4 were able to discontinue (2 had phlebotomy) and 5 continue to receive chelation (1 had phlebotomy). Analysis of iron marker stabilization after discontinuation of chelation will be presented. The median (range) change from baseline in LIC levels at month 48 was -3.9 (-22.3 to 10.5) mg Fe/g dry weight; the median (range) change from baseline in serum ferritin was -2119.0 (-7211 to 3889) pmoL/L. Reductions from baseline in serum TfR were observed at month 36; cardiac T2* remained stable at month 48 ( Table 1). Safety of beti-cel treatment largely reflected the known side effects of hematopoietic stem cell collection and the busulfan conditioning regimen. Conclusion: In this analysis with up to 9 years of follow up, patients treated with beti-cel who achieved TI also demonstrated sustained improvements in iron burden, and the majority of patients were able to stop chelation. Collectively, these results demonstrate the long-term durability and stability of response after beti-cel gene therapy in patients with TDT.

Entirely noninvasive outcome prediction in central nervous system lymphomas using circulating tumor DNA

AbstractState-of-the-art response assessment of central nervous system lymphoma (CNSL) by magnetic resonance imaging is challenging and an insufficient predictor of treatment outcomes. Accordingly, the development of novel risk stratification strategies in CNSL is a high unmet medical need. We applied ultrasensitive circulating tumor DNA (ctDNA) sequencing to 146 plasma and cerebrospinal fluid (CSF) samples from 67 patients, aiming to develop an entirely noninvasive dynamic risk model considering clinical and molecular features of CNSL. Our ultrasensitive method allowed for the detection of CNSL-derived mutations in plasma ctDNA with high concordance to CSF and tumor tissue. Undetectable plasma ctDNA at baseline was associated with favorable outcomes. We tracked tumor-specific mutations in plasma-derived ctDNA over time and developed a novel CNSL biomarker based on this information: peripheral residual disease (PRD). Persistence of PRD after treatment was highly predictive of relapse. Integrating established baseline clinical risk factors with assessment of radiographic response and PRD during treatment resulted in the development and independent validation of a novel tool for risk stratification: molecular prognostic index for CNSL (MOP-C). MOP-C proved to be highly predictive of outcomes in patients with CNSL (failure-free survival hazard ratio per risk group of 6.60; 95% confidence interval, 3.12-13.97; P < .0001) and is publicly available at www.mop-c.com. Our results highlight the role of ctDNA sequencing in CNSL. MOP-C has the potential to improve the current standard of clinical risk stratification and radiographic response assessment in patients with CNSL, ultimately paving the way toward individualized treatment.

Mass Spectrometry-Based Assessment of M-Protein in Peripheral Blood during Maintenance Therapy in Multiple Myeloma (MM) in the Phase III ATLAS Trial

Introduction Minimal residual disease (MRD) assessment in bone marrow (BM) has emerged as one of the strongest prognostic factors in MM. Mass spectrometry (MS), capable of detecting MM-derived monoclonal proteins in peripheral blood with high sensitivity, has the potential to complement standard methods. While its role in evaluating residual disease and its prognostic performance compared to routine MRD assessments is not yet established, other unanswered questions remain: (1) What is the role of MS in response assessment for patients without a high disease burden baseline sample? (2) What is the optimal timing of MS assessment, considering the long half-life of immunoglobulins? Methods Stored serum samples collected at different timepoints [screening, cycle 6 (C6), C12, C18, C24, C36] from patients treated in the ATLAS trial, were analyzed using the EXENT® Immunoglobulin isotypes (GAM) assay (EXENT® Solution, in development by The Binding Site, part of Thermo Fisher Scientific), which utilizes MALDI-TOF MS. ATLAS is an ongoing phase 3 trial that randomized 180 patients with newly diagnosed MM after autologous stem cell transplantation (ASCT) to maintenance therapy with carfilzomib, lenalidomide, and dexamethasone (KRd) or lenalidomide alone (R). In the KRd arm, patients with standard-risk cytogenetics who achieved MRD-negativity after cycle 6 de-escalated therapy to receive R, from C9. No baseline diagnostic samples were available, and samples were not available for every patient at every timepoint. A sample was called positive by MS when the EXENT® solution confirmed the presence of an M protein, matching the known (diagnostic) isotype. BM MRD was assessed at the same timepoints using multicolor flow cytometry (MFC) with a limit of detection (LoD) of 10 -5 and next-generation sequencing (NGS, clonoSEQ, Adaptive, LoD 10 -6). Progression-free survival (PFS) was analyzed using the Kaplan-Meier method, with log-rank test for comparisons between groups. The data cutoff (31-Dec-2021) was the same as was used in the ATLAS publication by Dytfeld et al. Lancet Oncology 2023. Results 585 samples from 138 patients were analyzed by MS. There were 349 paired BM MRD results by NGS; patients with MRD 10 -5 were considered MRD(+). The overall agreement between the two methods equaled 70%, with a comparable number of patients being MS+/NGS- (56/349, 16%) and MS-/NGS+ (50/349, 14%). The agreement at screening was 61%, but it improved at further timepoints and reached the highest level at C18 (74%). For BM MFC, there were 499 paired samples. There was 67% agreement, and the discrepancy was driven mostly by MS+/MFC- patients (125/499, 25%), whereas MS-/MFC+ was less frequent (40/499, 8%). The agreement was lowest at screening (60%), similarly to the NGS-based assessment, and reached the highest level at C18 (73%). Based on these findings, we concluded that C18 may be the optimal timepoint to assess prognostic role of MS results. Using the landmark method, MS(-) following C18 was associated with superior PFS compared to MS(+) [HR=0.39 (95% CI: 0.17-0.91), p=0.025; Figure 1]. MFC [HR=0.13 (0.04-0.35), p=0.0002], and NGS [HR=0.15 (0.03-0.63), p=0.003] statuses were also associated with PFS using this landmark method. Although small numbers of patients preclude definitive conclusions, we observed a similar effect size in outcomes among NGS(-)/MS(-) vs NGS(-)/MS(+) patients [HR=0.14 (0.01-1.58), p=0.06] and MFC(-)/MS(-) vs MFC(-)/MS(+) [HR=0.40 (0.13-1.27), p=0.11], both favoring BM MRD(-) with concurrent MS(-). Out of the 45 patients who were initially MS(+) and subsequently converted to MS(-), 23 (51%) occurred following C12 or later. Patients who converted from MS(+) to MS(-) had similar PFS to those with sustained MS(-) throughout the analyzed period [HR=0.74 (0.32-1.68), p=0.47; Figure 2], with the majority of PFS events in the converted group occurring during first 18 months of observation. Conclusions MS-based disease assessment in the post-ASCT setting is feasible in many cases, if information on the original MM clone is available by traditional methods. Our results suggest that the optimal timepoint for such evaluation can be as long as 18 months after ASCT. The EXENT® assay may be complementary to BM-based techniques for MRD assessment, allowing for more accurate prognostication when used in combination. Further studies are needed to confirm its exact timing and role in the disease evaluation algorithms.

Prospective inter- and intra-tracer repeatability analysis of radiomics features in [68Ga]Ga-PSMA-11 and [18F]F-PSMA-1007 PET scans in metastatic prostate cancer.

This study aimed to quantify both the intra- and intertracer repeatability of lesion-level radiomics features in [68Ga]Ga-prostate-specific membrane antigen (PSMA)-11 and [18F]F-PSMA-1007 positron emission tomography (PET) scans. Eighteen patients with metastatic prostate cancer (mPCa) were prospectively recruited for the study and randomised to one of three test-retest groups: (i) intratracer [68Ga]Ga-PSMA-11 PET, (ii) intratracer [18F]F-PSMA-1007 PET or (iii) intertracer between [68Ga]Ga-PSMA-11 and [18F]F-PSMA-1007 PET. Four conventional PET metrics (standardised uptake value (SUV)max, SUVmean, SUVtotal and volume) and 107 radiomics features were extracted from 75 lesions and assessed using the repeatability coefficient (RC) and the ICC. Radiomic feature repeatability was also quantified after the application of 16 filters to the PET image. Test-retest scans were taken a median of 5 days apart (range: 2-7 days). SUVmean demonstrated the lowest RC limits of the conventional features, with RCs of 7.9%, 14.2% and 24.7% for the [68Ga]Ga-PSMA-11 PET, [18F]F-PSMA-1007 PET, and intertracer groups, respectively. 69%, 66% and 9% of all radiomics features had good or excellent ICC values (ICC ≥ 0.75) for the same groups. Feature repeatability therefore diminished considerably for the intertracer group relative to intratracer groups. In this study, robust biomarkers for each tracer group that can be used in subsequent clinical studies were identified. Overall, the repeatability of conventional and radiomic features were found to be substantially lower for the intertracer group relative to both intratracer groups, suggesting that assessing patient response quantitatively should be done using the same radiotracer where possible. Intertracer biomarker repeatability limits are significantly larger than intratracer limits.

Post-acquisition standardization of positron emission tomography images

PurposeTissue radiotracer activity measured from positron emission tomography (PET) images is an important biomarker that is clinically utilized for diagnosis, staging, prognostication, and treatment response assessment in patients with cancer and other clinical disorders. Using PET image values to define a normal range of metabolic activity for quantification purposes is challenging due to variations in patient-related factors and technical factors. Although the formulation of standardized uptake value (SUV) has compensated for some of these variabilities, significant non-standardness still persists. We propose an image processing method to substantially mitigate these variabilities.MethodsThe standardization method is similar for activity concentration (AC) PET and SUV PET images with some differences and consists of two steps. The calibration step is performed only once for each of AC PET or SUV PET, employs a set of images of normal subjects, and requires a reference object, while the transformation step is executed for each patient image to be standardized. In the calibration step, a standardized scale is determined along with 3 key image intensity landmarks defined on it including the minimum percentile intensity smin, median intensity sm, and high percentile intensity smax. smin and sm are estimated based on image intensities within the body region in the normal calibration image set. The optimal value of the maximum percentile β corresponding to the intensity smax is estimated via an optimization process by using the reference object to optimally separate the highly variable high uptake values from the normal uptake intensities. In the transformation step, the first two landmarks—the minimum percentile intensity pα(I), and the median intensity pm(I)—are found for the given image I for the body region, and the high percentile intensity pβ(I) is determined corresponding to the optimally estimated high percentile value β. Subsequently, intensities of I are mapped to the standard scale piecewise linearly for different segments. We employ three strategies for evaluation and comparison with other standardization methods: (i) comparing coefficient of variation (CVO) of mean intensity within test objects O across different normal test subjects before and after standardization; (ii) comparing mean absolute difference (MDO) of mean intensity within test objects O across different subjects in repeat scans before and after standardization; (iii) comparing CVO of mean intensity across different normal subjects before and after standardization where the scans came from different brands of scanners.ResultsOur data set consisted of 84 FDG-PET/CT scans of the body torso including 38 normal subjects and two repeat-scans of 23 patients. We utilized one of two objects—liver and spleen—as a reference object and the other for testing. The proposed standardization method reduced CVO and MDO by a factor of 3–8 in comparison to other standardization methods and no standardization. Upon standardization by our method, the image intensities (both for AC and SUV) from two different brands of scanners become statistically indistinguishable, while without standardization, they differ significantly and by a factor of 3–9.ConclusionsThe proposed method is automatic, outperforms current standardization methods, and effectively overcomes the residual variation left over in SUV and inter-scanner variations.

Automated Brain Tumor Detection and Segmentation for Treatment Response Assessment Using Amino Acid PET.

Evaluation of metabolic tumor volume (MTV) changes using amino acid PET has become an important tool for response assessment in brain tumor patients. MTV is usually determined by manual or semiautomatic delineation, which is laborious and may be prone to intra- and interobserver variability. The goal of our study was to develop a method for automated MTV segmentation and to evaluate its performance for response assessment in patients with gliomas. Methods: In total, 699 amino acid PET scans using the tracer O-(2-[18F]fluoroethyl)-l-tyrosine (18F-FET) from 555 brain tumor patients at initial diagnosis or during follow-up were retrospectively evaluated (mainly glioma patients, 76%). 18F-FET PET MTVs were segmented semiautomatically by experienced readers. An artificial neural network (no new U-Net) was configured on 476 scans from 399 patients, and the network performance was evaluated on a test dataset including 223 scans from 156 patients. Surface and volumetric Dice similarity coefficients (DSCs) were used to evaluate segmentation quality. Finally, the network was applied to a recently published 18F-FET PET study on response assessment in glioblastoma patients treated with adjuvant temozolomide chemotherapy for a fully automated response assessment in comparison to an experienced physician. Results: In the test dataset, 92% of lesions with increased uptake (n = 189) and 85% of lesions with iso- or hypometabolic uptake (n = 33) were correctly identified (F1 score, 92%). Single lesions with a contiguous uptake had the highest DSC, followed by lesions with heterogeneous, noncontiguous uptake and multifocal lesions (surface DSC: 0.96, 0.93, and 0.81 respectively; volume DSC: 0.83, 0.77, and 0.67, respectively). Change in MTV, as detected by the automated segmentation, was a significant determinant of disease-free and overall survival, in agreement with the physician's assessment. Conclusion: Our deep learning-based 18F-FET PET segmentation allows reliable, robust, and fully automated evaluation of MTV in brain tumor patients and demonstrates clinical value for automated response assessment.

The Effectiveness of Risankizumab Following Guselkumab Failure in Moderate-to-Severe Psoriasis Patients: A Retrospective Study.

Psoriasis is a chronic inflammatory skin disease with a strong genetic predisposition and autoimmune component that is often treated with immunomodulators such as biologic therapy. Guselkumab is a biologic treatment option that selectively targets the p19 subunit of interleukin (IL)-23; risankizumab is a more recently developed monoclonal antibody of the same class that targets IL-23p19. There is limited research around effective treatment response with intra class switching within IL-23-targeted therapies for the treatment of moderate-to-severe plaque psoriasis. The purpose is to assess patient response to risankizumab after guselkumab failure for the treatment of plaque psoriasis. A retrospective chart review was conducted for 13 patients meeting inclusion criteria. Physical examination findings were converted to a 5-point static physicians' global assessment (sPGA) score. Baseline, 4-month, and 12-month sPGA scores were assigned from visits immediately prior to and during their course of risankizumab treatment. sPGA scores were analyzed to compare changes between baseline and 4 months and 12 months of therapy. Patients treated with risankizumab had lower sPGA scores after both 4 and 12 months compared to their baseline sPGA score. 46% of patients met the primary outcome of an sPGA score of 0 or 1 at 4 months of risankizumab, increasing to 90% of patients at 12 months. Our findings reflect an improvement in sPGA scores when patients are treated with risankizumab following guselkumab failure. This highlights the benefit of in-class switch to risankizumab when patients with moderate-to-severe plaque psoriasis have failed multiple treatments including guselkumab.

Cox proportional hazards deep neural network identifies peripheral blood complete remission to be at least equivalent to morphologic complete remission in predicting outcomes of patients treated with azacitidine-A prospective cohort study by the AGMT.

The current gold standard of response assessment in patients with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML) is morphologic complete remission (CR) and CR with incomplete count recovery (CRi), both of which require an invasive BM evaluation. Outside of clinical trials, BM evaluations are only performed in ~50% of patients during follow-up, pinpointing a clinical need for response endpoints that do not necessitate BM assessments. We define and validate a new response type termed "peripheral blood complete remission" (PB-CR) that can be determined from the differential blood count and clinical parameters without necessitating a BM assessment. We compared the predictive value of PB-CR with morphologic CR/CRi in 1441 non-selected, consecutive patients diagnosed with MDS (n = 522; 36.2%), CMML (n = 132; 9.2%), or AML (n = 787; 54.6%), included within the Austrian Myeloid Registry (aMYELOIDr; NCT04438889). Time-to-event analyses were adjusted for 17 covariates remaining in the final Cox proportional hazards (CPH) model. DeepSurv, a CPH neural network model, and permutation-based feature importance were used to validate results. 1441 patients were included. Adjusted median overall survival for patients achieving PB-CR was 22.8 months (95%CI 18.9-26.2) versus 10.4 months (95%CI 9.7-11.2) for those who did not; HR = 0.366 (95%CI 0.303-0.441; p < .0001). Among patients achieving CR, those additionally achieving PB-CR had a median adjusted OS of 32.6 months (95%CI 26.2-49.2) versus 21.7 months (95%CI 16.9-27.7; HR = 0.400 [95%CI 0.190-0.844; p = .0161]) for those who did not. Our deep neural network analysis-based findings from a large, prospective cohort study indicate that BM evaluations solely for the purpose of identifying CR/CRi can be omitted.

A Two-stage Diagnostic Framework for Post-ablation Treatment Response Assessment in Patients with Hepatocellular Carcinoma.

Contrast-enhanced ultrasound (CEUS) video plays an important role in post-ablation treatment response assessment in patients with hepatocellular carcinoma (HCC). However, the assessment of treatment response using CEUS video is challenging due to issues such as high inter-frame data repeatability, small ablation area and poor imaging quality of CEUS video. To address these issues, we propose a two-stage diagnostic framework for post-ablation treatment response assessment in patients with HCC using CEUS video. The first stage is a location stage, which is used to locate the ablation area. At this stage, we propose a Yolov5-SFT to improve the location results of the ablation area and a similarity comparison module (SCM) to reduce data repeatability. The second stage is an assessment stage, which is used for the evaluation of postoperative efficacy. At this stage, we design an EfficientNet-SK to improve assessment accuracy. The Experimental results on the self-collected data show that the proposed framework outperforms other selected algorithms, and can effectively assist doctors in the assessment of post-ablation treatment response.

A novel pyroptosis-related signature predicts prognosis and indicates immunotherapy in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) has been recognized as a frequently occurring oral malignant tumor. Pyroptosis plays an extremely important role in the occurrence and development of cancer, but the role of pyroptosis in OSCC remains unclear. OSCC-related data were obtained from the TCGA and GEO databases. A PSscore risk model was constructed through LASSO regression analysis. The GEO database was utilized as the validation set of the model. The "ESTIMATE" and "CIBERSORT" algorithms were utilized to additionally evaluate the relationship between the immune cell score and PSscore. TIDE and IPS algorithms were used to assess patient response to immunotherapy. In addition, Western blot analysis and MTT assay was used to further validate key genes. Comprehensive bioinformatics analysis showed that a low-PSscore had a significant survival advantage, richer immune cell infiltration, more active immune-related pathways, higher TME scores, and lower tumor purity. The results of TIDE and IPS analysis indicated that the high-PSscore group had higher immune escape potential and was less sensitive to immunotherapy. In contrast, the low-PSscore group patients might be more sensitive to PD1 and CTLA4 + PD1 immunotherapy. Univariate and multivariate COX results indicated that PSscore was an independent prognostic factor in OSCC patients. Another important finding is that BAK1 is a potential target of OSCC and is related to the Nod-like receptor signaling pathway. Knockdown of BAK1 can significantly reduce the proliferation of OSCC cells. The PSscore model could be utilized as a powerful prognostic indicator and can help in the development of new immunotherapies.

Castration-resistant prostate cancer (CRPC) on PSMA-PET: Imaging features, disease distribution, and a comparison to castration-sensitive prostate cancer (CSPC).

e17062 Background: 18F-DCFPyL PET/CT is increasingly used in the staging and response assessment of patients (pts) with prostate cancer. Recent studies suggest that short-term ADT increases prostate-specific membrane antigen (PSMA) expression, whereas long-term ADT suppresses PSMA. Changes in PSMA expression after the development of CRPC are uncertain. We described 18F-DCFPyL PET findings in pts with CRPC and compared them to findings in CSPC. Methods: We analyzed 538 18F-DCFPyL scans performed at our large academic center. CRPC was defined as rising PSA w/ testosterone &lt; 50 ng/dL on ADT. M0 CRPC was defined as absence of extra-pelvic disease (dz) and oligometastatic CRPC (oCRPC) was defined as ≤ 5 LN + osseous lesions and absence of visceral dz. Highest SUV max (hSUVmax) was abstracted from radiologist impression. Means between groups were compared using two-tailed t-tests; undetectable PSA levels were scored as “0”. Logistic regression was used to compare dz distribution between castrate states. Significance was defined as p &lt; 0.05. Results: There were 81 pts with CRPC, 72 pts with metastatic CRPC (mCRPC) and 123 pts with mCSPC. The median ages of pts with mCRPC (74.5 years) and mCSPC (71) were similar. The mean PSAs of mCSPC (20.2 ng/mL) and mCRPC (69.4) were significantly different. hSUVmax was higher in mCRPC (mean 40.3, 95% CI 32.7 – 47.8) than in mHSPC (22.6, 18.4 – 26.9), p &lt; 0.001. Distribution of mCRPC lesions was as follows: prostate bed (26.4%), local pelvic LN (25%), distant LN (M1a, 41.7%), osseous (M1b, 16.7%), and visceral (M1c, 16.7%). In a multivariate analysis mCRPC pts had lower rates of pelvic LN dz and higher rates of M1c, with a trend toward increased M1b (p &lt; 0.10), compared to mCSPC pts. ADT and androgen pathway inhibition did not affect hSUVmax in CRPC. Within CRPC, there were 9 pts with M0 dz, 24 pts with oCRPC, and 48 pts with polymetastatic dz (pmCRPC). The ages (Table) of pmCRPC and oCRPC pts were similar. The mean PSA of pmCRPC (100.9) was higher than that of oCRPC (8.8) and M0 CRPC (5.7). hSUVmax between oCRPC (40.3) and pmCRPC (40.3) was similar. Conclusions: The greater hSUVmax in mCRPC may implicate the effect of ADT on PSMA expression or may describe differing tumor biology. mCRPC pts had less local dz and more frequent distant metastases, likely reflecting more advanced disease. These findings will help inform detection of developing castrate resistance on PSMA-PET. More data are needed on the classification of oligometastatic dz on PSMA-PET and the impact of hormone therapy on PSMA in CRPC. [Table: see text]

A novel 89Zr-a-PD-1 immuno-PET-CT may improve pseudoprogression detection in a lung cancer murine model receiving immunotherapy.

e15116 Background: Immune checkpoint inhibitors (ICIs) have revolutionized lung cancer treatment improving survival outcomes of non-small cell lung cancer (NSCLC) patients. Response assessment of patients on ICIs treatment represents a challenge since an increase in tumor size or the appearance of new lesions might not reflect true disease progression (P) but pseudoprogression (PP), which has been reported in a range of 3-6% in NSCLC. Conventional 18F-FDG-PET scans do not accurately discriminate P from PP. We have recently reported the efficacy of a combined blockade of PD-1 and ID1 in NSCLC mouse model. We aimed to evaluate a novel 89Zr-labelled radiotracer for micro mPET-CT to detect PP in a NSCLC murine model. Methods: Syngeneic subcutaneous tumors were generated using LLC cells (with constitutive expression of ID1 or ID1-silenced) in C57BL6J and in ID1-deficient mice, treated with PBS or with a commercially available monoclonal antibody against PD-1 (a-PD-1) (RPM1-14, 300 mg, IP, on days 7, 10 and 14). Tumor growth and response to ID1-PD-1 blockade, was measured by 18F-FDG uptake. Additionally, PP was measured labelling the anti-PD-1 with 89Zr (89Zr-a-PD-1) and analyzing 89Zr uptake at day 15, 17 and 20. Tumor microenvironment was analyzed with immunohistochemistry, multiplex immunofluorescence and quantification of relative expression of interleukins by RT-PCR. Results: 18F-FDG uptake did not show significant differences between groups, underestimating the real metabolic response induced by the treatment. However, 89Zr-mPET-CT showed a significantly higher 89Zr uptake when ID1 was inhibited in both, tumor cells and tumor micro-environment and mice were treated with a-PD-1 (p = 0.0075). The analysis of the tumor tissues in those animals by immunohistochemistry and multiplex immunofluorescence disclosed an increase in immune T CD8+ cells infiltration, being responsible for the antitumor response observed and correlating with 89Zr signal. Moreover, the analysis of interleukins expression showed that tumors with ID1 inhibition in the tumor micro-environment presented an upregulation of pro-inflammatory interleukins, favoring T- cell infiltration. Conclusions: ID1 inhibition in tumor cells and in tumor micro-environment combined with PD-1 blockade enhanced immune cell infiltration through pro-inflammatory interleukins upregulation. 89Zr-a-PD-1 immuno-PET-CT may improve PP detection in a NSCLC murine model receiving immunotherapy.