Radiomic analysis of patient and inter-organ heterogeneity in response to immunotherapies and BRAF targeted therapy in metastatic melanoma

Background

Variability in treatment response may be attributable to organ-level heterogeneity in tumor lesions. Radiomic analysis of medical images can elucidate non-invasive biomarkers of clinical outcome. Organ-specific radiomic comparison across immunotherapies and targeted therapies has not been previously reported.

Methods

We queried UPMC Hillman Cancer Center registry for patients with metastatic melanoma (MEL) treated with immune checkpoint inhibitors (ICI) (anti-PD1/CTLA4 [ipilimumab+nivolumab; I+N] or anti-PD1 monotherapy) or BRAF targeted therapy. Best overall response was measured using RECIST v1.1. Lesions were segmented into discrete volume-of-interest with 400 radiomics features extracted. Overall and organ-specific machine-learning models were constructed to predict disease control (DC) versus progressive disease (PD) using XGBoost.

Results

291 MEL patients were identified, including 242 ICI (91 I+N, 151 PD1) and 49 BRAF. 667 metastases were analyzed, including 541 ICI (236 I+N, 305 PD1) and 126 BRAF. Across cohorts, baseline demographics included 39-47% female, 24-29% M1C, 24-46% M1D, and 61-80% with elevated LDH. Among patients experiencing DC, the organs with the greatest reduction were liver (-88%±12%, I+N; mean±S.E.M.) and lung (-72%±8%, I+N). For patients with multiple same-organ target lesions, the highest inter-lesion heterogeneity was observed in brain among patients who received ICI while no intra-organ heterogeneity was observed in BRAF. 267 patients were kept for radiomic modeling, including 221 ICI (86 I+N, 135 PD1) and 46 BRAF. Models consisting of optimized radiomic signatures classified DC/PD across I+N (AUC=0.85) and PD1 (0.71) and within individual organ sites (AUC=0.72∼0.94). Integration of clinical variables improved the models' performance. Comparison of models between treatments and across organ sites suggested mostly non-overlapping DC or PD features. Skewness, kurtosis, and informational measure of correlation (IMC) were among the radiomic features shared between overall response models. Kurtosis and IMC were also utilized by multiple organ-site models.

Conclusions

Differential organ-specific response was observed across BRAF and ICI with within organ heterogeneity observed for ICI but not for BRAF. Radiomic features of organ-specific response demonstrated little overlap. Integrating clinical factors with radiomics improves the prediction of disease course outcome and prediction of tumor heterogeneity.

Associating T1-Weighted and T2-Weighted Magnetic Resonance Imaging Radiomic Signatures With Preoperative Symptom Severity in Patients With Cervical Spondylotic Myelopathy

BACKGROUND

Preoperative symptom severity in cervical spondylotic myelopathy (CSM) can be variable. Radiomic signatures could provide an imaging biomarker for symptom severity in CSM. This study utilizes radiomic signatures of T1-weighted and T2-weighted magnetic resonance imaging images to correlate with preoperative symptom severity based on modified Japanese Orthopaedic Association (mJOA) scores for patients with CSM.

METHODS

Sixty-two patients with CSM were identified. Preoperative T1-weighted and T2-weighted magnetic resonance imaging images for each patient were segmented from C2-C7. A total of 205 texture features were extracted from each volume of interest. After feature normalization, each second-order feature was further subdivided to yield a total of 400 features from each volume of interest for analysis. Supervised machine learning was used to build radiomic models.

RESULTS

The patient cohort had a median mJOA preoperative score of 13; of which, 30 patients had a score of >13 (low severity) and 32 patients had a score of ≤13 (high severity). Radiomic analysis of T2-weighted imaging resulted in 4 radiomic signatures that correlated with preoperative mJOA with a sensitivity, specificity, and accuracy of 78%, 89%, and 83%, respectively (P < 0.004). The area under the curve value for the ROC curves were 0.69, 0.70, and 0.77 for models generated by independent T1 texture features, T1 and T2 texture features in combination, and independent T2 texture features, respectively.

CONCLUSIONS

Radiomic models correlate with preoperative mJOA scores using T2 texture features in patients with CSM. This may serve as a surrogate, objective imaging biomarker to measure the preoperative functional status of patients.

Creating a Sustainable Foundation for IR Services and Training in Sub-Saharan Africa: 5-Year Update on the Road2IR Initiative

PURPOSE

To evaluate the growth and quality of an interventional radiology (IR) training model designed for resource-constrained settings and implemented in Tanzania as well as its overall potential to increase access to minimally invasive procedures across the region.

MATERIALS AND METHODS

IR training in Tanzania began in October 2018 through monthly deployment of visiting teaching teams for hands-on training combined with in-person and remote lectures. A competency-based 2-year Master of Science in IR curriculum was inaugurated at the nation's main teaching hospital in October 2019, with the first 2 classes graduating in 2021 and 2022. Procedural data, demographics, and clinical outcomes were collected and analyzed throughout the duration of this program.

RESULTS

From October 2018 to July 2022, 1,595 procedures were performed in Tanzania: 1,236 nonvascular and 359 vascular, all with local fellows as primary interventional radiologists. Of these, 97.2% were technically successful, 95.2% were without adverse events, and 28.9% were performed independently by Tanzanian fellows and faculty with no difference in adverse event and technical success rates (P = .63 and P = .90, respectively), irrespective of procedural class. Ten IR physicians graduated from this program during the study period, followed by another 3 per year going forward. Partner training programs in Uganda and Rwanda mirroring this model commenced in 2023 and 2024, respectively.

CONCLUSIONS

The reported training model offers a practical and effective solution to meet many of the challenges associated with the lack of access to IR in sub-Saharan Africa.

Validation of a multiomic model of plasma extracellular vesicle PD-L1 and radiomics for prediction of response to immunotherapy in NSCLC

BACKGROUND

Immune-checkpoint inhibitors (ICIs) have showed unprecedent efficacy in the treatment of patients with advanced non-small cell lung cancer (NSCLC). However, not all patients manifest clinical benefit due to the lack of reliable predictive biomarkers. We showed preliminary data on the predictive role of the combination of radiomics and plasma extracellular vesicle (EV) PD-L1 to predict durable response to ICIs.

MAIN BODY

Here, we validated this model in a prospective cohort of patients receiving ICIs plus chemotherapy and compared it with patients undergoing chemotherapy alone. This multiparametric model showed high sensitivity and specificity at identifying non-responders to ICIs and outperformed tissue PD-L1, being directly correlated with tumor change.

SHORT CONCLUSION

These findings indicate that the combination of radiomics and EV PD-L1 dynamics is a minimally invasive and promising biomarker for the stratification of patients to receive ICIs.

Subcutaneous wound infiltration of ketamine is superior to bupivacaine in terms of pain perception and opioid consumption after cesarean section: a double-blinded randomized placebo-controlled clinical trial

OBJECTIVE

The aim of the present study was to evaluate the analgesic efficiency of SC ketamine, either alone or in combination with bupivacaine, following CS by means of postoperative pain and opioid need.

PATIENTS AND METHODS

One hundred and twenty women were allocated into 4 groups in this prospective, double-blind, placebo-controlled, randomized trial. Group K (Ketamine, n=30) received SC 1 mg/kg ketamine. Group B (Bupivacaine, n=30) received SC 20 mL bupivacaine 0.5%. Group KB (Ketamine+Bupivacaine, n=30) received SC ketamine 1 mg/kg plus SC 20 mL bupivacaine 0.5%. Group P (Placebo, n=30) received SC 30 mL 0.9% saline (placebo).

RESULTS

VAS scores at resting and on coughing and analgesic consumptions were compared. Visual analogue scale (VAS) pain scores at rest and coughing, at 15 and 60 minutes, and 2, 6 and 12 hours, and total opioid necessity were measured. VAS scores at rest in Group P were higher than in Group KB at the 6th hour, while lower in Group K and Group KB than in Groups B or P at the 12th hour. Patients receiving placebo had higher coughing VAS scores than those receiving ketamine or ketamine+bupivacaine at 2nd, 6th and 12th hours. Patients in Groups P and B required higher doses of morphine than those in groups K or KB.

CONCLUSIONS

Subcutaneous ketamine, either alone or in combination with bupivacaine, provides a better postoperative pain relief and reduces postoperative opioid consumption when compared to use of bupivacaine alone.

The comparison of intraincisional bupivacaine infiltration and intravenous paracetamol administration for pain alleviation after cesarean section: a double-blinded randomized placebo controlled clinical trial

OBJECTIVE

This study aimed to compare the analgesic effect of subcutaneous (SC) bupivacaine and intravenous (IV) paracetamol on postoperative pain and opioid requisites in patients undergoing cesarean delivery.

PATIENTS AND METHODS

One hundred and five women were allocated into 3 groups in this prospective, double-blind, placebo-controlled, randomized trial. Group 1 received SC bupivacaine, Group 2 received IV paracetamol following surgery and every 6 hours for 24 hours in the postoperative period, Group 3 received SC 0.9% saline and IV 0.9% saline at similar periods. Visual analogue scale (VAS) pain scores at rest and coughing, at 15 and 60 minutes, and 2, 6 and 12 hours, and total opioid necessity were measured.

RESULTS

VAS scores at rest were higher in placebo group than in bupivacaine and paracetamol groups at 15 minutes (p=0.047) and 2 hours (p=0.004). VAS scores at coughing were higher in placebo group than in bupivacaine and paracetamol groups at 2 hour (p=0.001) and 6 hours (p=0.018). Placebo group needed higher (p<0.001) doses of morphine than paracetamol or bupivacaine groups.

CONCLUSIONS

Intravenous paracetamol decreases pain scores similar to SC bupivacaine in the postoperative period compared to placebo. Patients taking bupivacaine or paracetamol need fewer opioids than placebo.

Federated learning enables big data for rare cancer boundary detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.

Disrupted redox balance in utero-placenteal junction may be the main culprit in the occurrence of abruptio placenta

OBJECTIVE

To determine the oxidant/antioxidant balance and proinflammatory status in amniotic fluids collected during cesarean section of patients diagnosed with abruptio placenta.

PATIENTS AND METHODS

Twenty-five patients diagnosed with ablatio placenta with intact membranes who went to emergency cesarean section were included in the study. A diagnosis of AP was made in those who had at least one of the following criteria or, in suspicious cases, two findings. (i) Antepartum hemorrhage starting after 20 weeks of gestation, (ii) presence of retroplacental hematoma on ultrasonography, (iii) severe fetal distress or death, (iv) localized or diffuse uterine tenderness or pain. The control group consisted of 25 patients who presented for delivery, who were not diagnosed with AP, and whose membranes were intact. NF-κB, total oxidant capacity (TOC), total antioxidant capacity (TAC), and oxidative stress index (TOC/TAC=OSI) levels were measured in amniotic fluids collected during cesarean section from both groups.

RESULTS

Amniotic fluid TAS values of the AP group were significantly lower than the healthy controls (1.14±0.33 vs. 9.05.±3.40, p<0.01). Amniotic fluid TOS values were significantly increased in the AP group (36.1±8.10 vs. 11.4±2.77, p<0.02). OSI values were significantly higher in the AP group (31.6±9.03 vs. 1.26±0.02, p<0.01). Amniotic fluid NF-κB expression of the AP group was approximately 5 times higher than the control group (10.4±2.56 ng/mL vs. 1.86±0.30 ng/mL, p<0.01). High blood pressure and smoking history were significantly higher in the AP group. Gestational age and fetal birth weight of the AP group were lower than the control group.

CONCLUSIONS

Since the increase in amniotic fluid oxidant capacity and proinflammatory cytokine synthesis cannot be neutralized by the antioxidant system, hypoxic cell damage may lead to premature separation of the placenta.

NIMG-67. MULTI-PARAMETRIC MRI-BASED MACHINE LEARNING ANALYSIS FOR PREDICTION OF NEOPLASTIC INFILTRATION AND RECURRENCE IN PATIENTS WITH GLIOBLASTOMA: UPDATES FROM THE MULTI-INSTITUTIONAL RESPOND CONSORTIUM

PURPOSE

Glioblastoma is extremely infiltrative with malignant cells extending beyond the enhancing rim where recurrence inevitably occurs, despite aggressive multimodal therapy. We hypothesize that important characteristics of peritumoral tissue heterogeneity captured and analyzed by multi-parametric MRI and artificial intelligence (AI) methods are generalizable in the updated multi-institutional ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium and predictive of neoplastic infiltration and future recurrence.

METHODS

We used the most recent update of the ReSPOND consortium to evaluate and further refine generalizability of our methods with different scanners and acquisition settings. 179 de novo glioblastoma patients with available T1, T1Gd, T2, T2-FLAIR, and ADC sequences at pre-resection baseline and after complete resection with subsequent pathology-confirmed recurrence were included. To establish generalizability of the predictive models, training and testing of the refined AI model was performed through Leave-One-Institution-Out-Cross-Validation schema. The multi-institutional cohort consisted of the Hospital of the University of Pennsylvania (UPenn, 124), Case Western Reserve University/University Hospitals (CWRU/UH, 27), New York University (NYU, 13), Ohio State University (OSU, 13), and University Hospital Río Hortega (RH, 2). Features extracted from pre-resection MRI were used to build the model predicting the spatial pattern of subsequent tumor recurrence. These predictions were evaluated against regions of pathology-confirmed post-resection recurrence.

RESULTS

Our model predicted the locations that later harbored tumor recurrence with overall odds ratio (99% CI)/AUC (99% CI), 12.0(11.8-12.2)/0.80(0.76-0.85), and per institute, CWRU/UH, 11.0(10.7-11.3)/0.80 (0.64-0.97); NYU, 7.0(6.7-7.3)/0.78(0.56-1.00); OSU, 18.3(17.5-19.1)/0.83(0.54-1.00); RH, 40.0(35.3-45.5)/0.93(0.00-1.00); UPenn, 8.00(7.7-8.3)/0.80(0.75-0.84).

CONCLUSION

This study provides extensive multi-institutional validated evidence that machine learning tools can identify peritumoral neoplastic infiltration and predict location of future recurrence, by decrypting the MRI signal heterogeneity in peritumoral tissue. Our analyses leveraged the unique dataset of the ReSPOND consortium, which aims to develop and validate AI-based biomarkers for individualized prediction and prognostication and establish generalizability in a multi-institutional setting.

NIMG-33. PROGNOSTIC STRATIFICATION OF DE NOVO GLIOBLASTOMA PATIENTS ACROSS 22 GEOGRAPHICALLY DISTINCT INSTITUTIONS: UPDATES FROM THE RESPOND CONSORTIUM

PURPOSE

Glioblastoma, IDH-wildtype, is the most common primary malignant adult brain tumor with median overall survival (OS) of ~14 months, with little improvement over the last 20 years. We hypothesize that AI-based integration of quantitative tumor characteristics, independent of acquisition protocol and equipment, can reveal accurate generalizable prognostic stratification. We seek an AI-based OS predictor using routine clinically acquired MRI sequences, quantitatively evaluated across institutions of the ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium.

METHODS

We identified a retrospective cohort of 2,293 diffuse glioma (IDH-wildtype/-NOS/-NEC) patients from 22 geographically distinct institutions across 3 continents, with preoperative structural MRI scans. The entire tumor burden was automatically segmented into 3 sub-compartments, i.e., enhancing, necrotic, peritumoral T2-FLAIR abnormality. We developed our AI predictor by multivariate integration of i)patient age, ii)tumor sub-compartment volume normalized to brain volume, iii)spatial distribution characteristics (tumor location, distance to the ventricles, and laterality), and iv)morphologic descriptors (major axes’ length, axes’ ratio, extent, and number of tumors). The AI predictor returns a continuous value between 0-1, defining short-, intermediate-, and long-survivors based on thresholds on the 25th and 75th percentiles. Leave-One-Site-Out-Cross-Validation was used to assess the generalizability of our stratification. Kaplan-Meier survival curves were computed for OS analysis and evaluated by a Cox proportional hazards model for statistical significance and hazard ratios.

RESULTS

Survival analysis yielded a hazard ratio of 2.07 (95%CI, 2.06-2.08, p-value= 4.8e-102) for patient stratification into short-, intermediate-, and long-survivors. Pearson correlation between the predicted and actual OS yielded an R= 0.49.

CONCLUSION

Multivariate integration of visually quantified tumor characteristics, agnostic to acquisition protocol/equipment, yields an accurate OS surrogate index. Validation of our AI model in the largest centralized glioblastoma imaging dataset, from the ReSPOND consortium, supports its generalizability across diverse patient populations and acquisition settings, potentially contributing to equitable improvements of personalized patient care.

Psoriasis patients' characteristics associated with high PASI response to tildrakizumab: an international dual center study

OBJECTIVE

Heterogeneous real-world evidence can complement the more strictly regulated clinical trial data. A benefit of this is the wide range of backgrounds, comorbidities and characteristics that can give additional insights into treatments. Observational, retrospective studies can help to fill in the mosaic that makes up a treatments landscape. Tildrakizumab, an interleukin 23p19 inhibitor, is approved for the treatment of plaque psoriasis and has been shown to be a safe and efficacious therapy in clinical trials and emerging real-world evidence. We aimed at confirming the efficacy of tildrakizumab in patients with plaque psoriasis in a dual center setting and identifying patients' characteristics leading to better treatment response.

PATIENTS AND METHODS

Patients with moderate to severe plaque psoriasis, eligible for systemic biological treatment, and treated with tildrakizumab were included in the study and the routine clinical parameters - Psoriasis Area and Severity Index (PASI), Dermatology Life Quality Index (DLQI), and safety - were retrospectively analyzed.

RESULTS

The combined cohorts included 89 patients, of which 64% were naïve to biologic therapies. At the time of analysis efficacy assessment was available for 39 patients after 12 months of treatment, 73 patients after 36 weeks, 79 patients after 16 weeks and 82 patients after 4 weeks. PASI and DLQI decreased significantly over time, with 52/73 (71.2%) patients achieving PASI 100 after 36 weeks. No severe side-effects were recorded in association with tildrakizumab.

CONCLUSIONS

We confirmed the safety and efficacy of tildrakizumab in a real-world clinical setting. A higher proportion of patients naïve to biologics achieved a greater PASI response than patients who had previously been treated with biologics. The same was true for older patients and patients with a shorter history of disease.

The Resolution Rate of Pulmonary Embolism on CT Pulmonary Angiography: a Prospective Study

PURPOSE

To prospectively assess the rate of clot resolution from CT pulmonary angiography (CTPA) in patients with acute pulmonary embolism (PE).

MATERIALS AND METHODS

This prospective cohort study included 290 patients (136 men, 154 women; mean age, 51.9 years) with acute PE. All patients had a CTPA at the presentation and had at least one follow-up within 6 months (mean 72.7 days). Sixty-four percent of patients had follow-up scans for research purposes within a pre-determined period (between 28 and 184 days; mean, 78.27 days) and 36 % had (between 2 and 184 days; mean, 62.78 days) for a clinical indication. The volume of each clot was measured using a semi-automated quantification program. The resolution rate was evaluated by interval-censored analysis.

RESULTS

The overall estimated probability of complete resolution was 42 % at 7 days, 56 % at 10 days, and 71 % at 45 days. Achieving complete resolution was significantly faster in patients with peripheral clots (HR: 1.78; CI: 1.05-3.03, p = 0.032) but slower in patients with consolidation and history of venous thromboembolism (VTE), (HR: 0.37; CI: 0.18-0.79, p = 0.01 and HR: 0.57; CI: 0.35-0.91, p = 0.019, respectively). Although the patients with cancer showed a faster resolution rate (HR: 1.67; CI: 1.05-2.68, p = 0.032), the mortality rate was significantly higher than non-cancer patients.

CONCLUSION

The resolution rate of clot burden in acute PE was associated with patients' clinical presentation variables and CTPA imaging biomarkers. This information may be incorporated into designing a prediction rule and determining the appropriate duration of anticoagulation therapy in patients with acute PE.

Extracellular vesicle PD-L1 dynamics predict durable response to immune-checkpoint inhibitors and survival in patients with non-small cell lung cancer

BACKGROUND

Immune-checkpoint inhibitors (ICIs) changed the therapeutic landscape of patients with lung cancer. However, only a subset of them derived clinical benefit and evidenced the need to identify reliable predictive biomarkers. Liquid biopsy is the non-invasive and repeatable analysis of biological material in body fluids and a promising tool for cancer biomarkers discovery. In particular, there is growing evidence that extracellular vesicles (EVs) play an important role in tumor progression and in tumor-immune interactions. Thus, we evaluated whether extracellular vesicle PD-L1 expression could be used as a biomarker for prediction of durable treatment response and survival in patients with non-small cell lung cancer (NSCLC) undergoing treatment with ICIs.

METHODS

Dynamic changes in EV PD-L1 were analyzed in plasma samples collected before and at 9 ± 1 weeks during treatment in a retrospective and a prospective independent cohorts of 33 and 39 patients, respectively.

RESULTS

As a result, an increase in EV PD-L1 was observed in non-responders in comparison to responders and was an independent biomarker for shorter progression-free survival and overall survival. To the contrary, tissue PD-L1 expression, the commonly used biomarker, was not predictive neither for durable response nor survival.

CONCLUSION

These findings indicate that EV PD-L1 dynamics could be used to stratify patients with advanced NSCLC who would experience durable benefit from ICIs.

Cancer Imaging in Immunotherapy

Immune therapeutics are revolutionizing cancer treatments. In tandem, new and confounding imaging characteristics have appeared that are distinct from those typically seen with conventional cytotoxic therapies. In fact, only 10% of patients on immunotherapy may show tumor shrinkage, typical of positive responses on conventional therapy. Conversely, those on immune therapies may initially demonstrate a delayed response, transient enlargement followed by tumor shrinkage, stable size, or the appearance of new lesions. Response Evaluation Criteria in Solid Tumors (RECIST) or WHO criteria, developed to identify early effects of cytotoxic agents, may not provide a complete evaluation of new emerging treatment response pattern of immunotherapeutic agents. Therefore, new imaging response criteria, such as the immune-related Response Evaluation Criteria in Solid Tumors (irRECIST), immune Response Evaluation Criteria in Solid Tumors (iRECIST), and immune-related Response Criteria (irRC), are proposed. However, FDA approval of emerging therapies including immunotherapies still relies on the current RECIST criteria. In this chapter, we review the traditional and new imaging response criteria for evaluation of solid tumors and briefly touch on some of the more commonly associated immunotherapy-induced adverse events.

NIMG-39. RADIOMIC ANALYSIS FOR NON-INVASIVE IN VIVO PROGNOSTIC STRATIFICATION OF DE NOVO GLIOBLASTOMA PATIENTS: A MULTI-INSTITUTIONAL EVALUATION FOR GENERALIZABILITY IN THE RESPOND CONSORTIUM

PURPOSE

Multi-parametric MRI based radiomic signatures have highlighted the promise of artificial intelligence (AI) in neuro-oncology. However, inter-institution heterogeneity hinders generalization to data from unseen clinical institutions. To this end, we formulated the ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium for glioblastoma. Here, we seek non-invasive generalizable radiomic signatures from routine clinically-acquired MRI for prognostic stratification of glioblastoma patients.

METHODS

We identified a retrospective cohort of 606 patients with near/gross total tumor resection ( &gt;90%), from 13 geographically-diverse institutions. All pre-operative structural MRI scans (T1,T1-Gd,T2,T2-FLAIR) were aligned to a common anatomical atlas. An automatic algorithm segmented the whole tumors (WTs) into 3 sub-compartments, i.e., enhancing (ET), necrotic core (NC), and peritumoral T2-FLAIR signal abnormality (ED). The combination of ET+NC defines the tumor core (TC). Quantitative radiomic features were extracted to generate our AI model to stratify patients into short- (&lt; 14mts) and long-survivors ( &gt;14mts). The model trained on 276 patients from a single institution was independently validated on 330 unseen patients from 12 left-out institutions, using the area-under-the-receiver-operating-characteristic-curve (AUC).

RESULTS

Each feature individually offered certain (limited but reproducible) value for identifying short-survivors: 1) TC closer to lateral ventricles (AUC=0.62); 2) larger ET/brain (AUC=0.61); 3) larger TC/brain (AUC=0.59); 4) larger WT/brain (AUC=0.55); 5) larger ET/WT (AUC=0.59); 6) smaller ED/WT (AUC=0.57); 7) larger ventricle deformations (AUC=0.6). Integrating all features and age, through a multivariate AI model, resulted in higher accuracy (AUC=0.7; 95% C.I.,0.64-0.77).

CONCLUSION

Prognostic stratification using basic radiomic features is highly reproducible across diverse institutions and patient populations. Multivariate integration yields relatively more accurate and generalizable radiomic signatures, across institutions. Our results offer promise for generalizable non-invasive in vivo signatures of survival prediction in patients with glioblastoma. Extracted features from clinically-acquired imaging, renders these signatures easier for clinical translation. Large-scale evaluation could contribute to improving patient management and treatment planning.

*Indicates equal authorship.

NIMG-22. PREDICTION OF GLIOBLASTOMA CELLULAR INFILTRATION AND RECURRENCE USING MACHINE LEARNING AND MULTI-PARAMETRIC MRI ANALYSIS: RESULTS FROM THE MULTI-INSTITUTIONAL RESPOND CONSORTIUM

PURPOSE

Multi-parametric MRI and artificial intelligence (AI) methods were previously used to predict peritumoral neoplastic cell infiltration and risk of future recurrence in glioblastoma, in single-institution studies. We hypothesize that important characteristics of peritumoral tissue heterogeneity captured, engineered/selected, and quantified by these methods relate to predictions generalizable in the multi-institutional ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium.

METHODS

To support further development, generalization, and clinical translation of our proposed method, we trained the AI model on a retrospective cohort of 29 de novo glioblastoma patients from the Hospital of the University of Pennsylvania (UPenn) (Male/Female:20/9, age:22-78 years) followed by evaluation on a prospective multi-institutional cohort of 84 glioblastoma patients (Male/Female:51/33, age:34-89 years) from Case Western Reserve University/University Hospitals (CWRU/UH, 25), New York University (NYU, 13), Ohio State University (OSU, 13), University Hospital Río Hortega (RH, 2), and UPenn (31). Features extracted from pre-resection MRI (T1, T1-Gd, T2, T2-FLAIR, ADC) were used to build our model predicting the spatial pattern of subsequent tumor recurrence. These predictions were evaluated against regions of pathology-confirmed post-resection recurrence.

RESULTS

Our model predicted the locations that later harbored tumor recurrence with sensitivity 83%, AUC 0.83 (99% CI, 0.73-0.93), and odds ratio 7.23 (99% CI, 7.09-7.37) in the prospective cohort. Odds ratio (99% CI)/AUC(99% CI) per institute were: CWRU/UH, 7.8(7.6-8.1)/0.82(0.75-0.89); NYU, 3.5(3.3-3.6)/0.84(074-0.93); OSU, 7.9(7.6-8.3)/0.8(0.67-0.94); RH, 22.7(20-25.1)/0.94(0.27-1); UPenn, 7.1(6.8-7.3)/0.83(0.76-0.91).

CONCLUSION

This is the first study that provides relatively extensive multi-institutional validated evidence that AI can provide good predictions of peritumoral neoplastic cell infiltration and future recurrence, by dissecting the MRI signal heterogeneity in peritumoral tissue. Our analyses leveraged the unique dataset of the ReSPOND consortium, which aims to develop and evaluate AI-based biomarkers for individualized prediction and prognostication, by moving from single-institution studies to generalizable, well-validated multi-institutional predictive biomarkers.

Evolving Role and Translation of Radiomics and Radiogenomics in Adult and Pediatric Neuro-Oncology

Exponential technologic advancements in imaging, high-performance computing, and artificial intelligence, in addition to increasing access to vast amounts of diverse data, have revolutionized the role of imaging in medicine. Radiomics is defined as a high-throughput feature-extraction method that unlocks microscale quantitative data hidden within standard-of-care medical imaging. Radiogenomics is defined as the linkage between imaging and genomics information. Multiple radiomics and radiogenomics studies performed on conventional and advanced neuro-oncology image modalities show that they have the potential to differentiate pseudoprogression from true progression, classify tumor subgroups, and predict recurrence, survival, and mutation status with high accuracy. In this article, we outline the technical steps involved in radiomics and radiogenomics analyses with the use of artificial intelligence methods and review current applications in adult and pediatric neuro-oncology.

Novel theranostic agent for PET imaging and targeted radiopharmaceutical therapy of tumour-infiltrating immune cells in glioma

BACKGROUND

Malignant gliomas are deadly tumours with few therapeutic options. Although immunotherapy may be a promising therapeutic strategy for treating gliomas, a significant barrier is the CD11b+ tumour-associated myeloid cells (TAMCs), a heterogeneous glioma infiltrate comprising up to 40% of a glioma's cellular mass that inhibits anti-tumour T-cell function and promotes tumour progression. A theranostic approach uses a single molecule for targeted radiopharmaceutical therapy (TRT) and diagnostic imaging; however, there are few reports of theranostics targeting the tumour microenvironment.

METHODS

Utilizing a newly developed bifunctional chelator, Lumi804, an anti-CD11b antibody (αCD11b) was readily labelled with either Zr-89 or Lu-177, yielding functional radiolabelled conjugates for PET, SPECT, and TRT.

FINDINGS

89Zr/177Lu-labeled Lumi804-αCD11b enabled non-invasive imaging of TAMCs in murine gliomas. Additionally, 177Lu-Lumi804-αCD11b treatment reduced TAMC populations in the spleen and tumour and improved the efficacy of checkpoint immunotherapy.

INTERPRETATION

89Zr- and 177Lu-labeled Lumi804-αCD11b may be a promising theranostic pair for monitoring and reducing TAMCs in gliomas to improve immunotherapy responses.

FUNDING

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Author response to Cunha et al

The need to identify biomarkers to predict immunotherapy response for rare cancers has been long overdue. We aimed to study this in our paper, 'Radiomics analysis for predicting pembrolizumab response in patients with advanced rare cancers'. In this response to the Letter to the Editor by Cunha et al, we explain and discuss the reasons behind choosing LASSO (Least Absolute Shrinkage and Selection Operator) and XGBoost (eXtreme Gradient Boosting) with LOOCV (Leave-One-Out Cross-Validation) as the feature selection and classifier method, respectively for our radiomics models. Also, we highlight what care was taken to avoid any overfitting on the models. Further, we checked for the multicollinearity of the features. Additionally, we performed 10-fold cross-validation instead of LOOCV to see the predictive performance of our radiomics models.

Radiomics analysis for predicting pembrolizumab response in patients with advanced rare cancers

BACKGROUND

We present a radiomics-based model for predicting response to pembrolizumab in patients with advanced rare cancers.

METHODS

The study included 57 patients with advanced rare cancers who were enrolled in our phase II clinical trial of pembrolizumab. Tumor response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and immune-related RECIST (irRECIST). Patients were categorized as 20 "controlled disease" (stable disease, partial response, or complete response) or 37 progressive disease). We used 3D-slicer to segment target lesions on standard-of-care, pretreatment contrast enhanced CT scans. We extracted 610 features (10 histogram-based features and 600 second-order texture features) from each volume of interest. Least absolute shrinkage and selection operator logistic regression was used to detect the most discriminatory features. Selected features were used to create a classification model, using XGBoost, for the prediction of tumor response to pembrolizumab. Leave-one-out cross-validation was performed to assess model performance.

FINDINGS

The 10 most relevant radiomics features were selected; XGBoost-based classification successfully differentiated between controlled disease (complete response, partial response, stable disease) and progressive disease with high accuracy, sensitivity, and specificity in patients assessed by RECIST (94.7%, 97.3%, and 90%, respectively; p<0.001) and in patients assessed by irRECIST (94.7%, 93.9%, and 95.8%, respectively; p<0.001). Additionally, the common features of the RECIST and irRECIST groups also highly predicted pembrolizumab response with accuracy, sensitivity, specificity, and p value of 94.7%, 97%, 90%, p<0.001% and 96%, 96%, 95%, p<0.001, respectively.

CONCLUSION

Our radiomics-based signature identified imaging differences that predicted pembrolizumab response in patients with advanced rare cancer.

INTERPRETATION

Our radiomics-based signature identified imaging differences that predicted pembrolizumab response in patients with advanced rare cancer.

Imaging findings of a rare pararectal splenosis and literature review

Pararectal splenosis is an extremely rare lesion caused by ectopic auto-transplantation of splenic tissue after splenic trauma or splenectomy. It is often asymptomatic and detected incidentally during radiologic evaluation. We present a 24-year-old male with pararectal splenosis. The patient had a history of splenectomy and presented with complaints of abdominal discomfort and chronic constipation. Contrast-enhanced computed tomography (CT) revealed multiple well-enhanced masses located in the abdominal cavity and one mass in pararectal area. Additionally, the pararectal lesion showed diffusion restriction on diffusion-weighted magnetic resonance imaging (DW-MRI). In this case report, we aim to highlight the significance of taking a detailed medical history; and using DW-MRI for diagnosis of splenosis by presenting a case in a rare location.

Comparison of the effects of dexmedetomidine and remifentanil on potential extreme haemodynamic and respiratory response following mask ventilation and laryngoscopy in patients with mandibular fractures

OBJECTIVE

The safety profile and efficacy were compared for remifentanil and dexmedetomidine with respect to haemodynamic and respiratory response during mask ventilation and laryngoscopy in patients with mandibular fractures.

PATIENTS AND METHODS

Seventy patients undergoing elective mandibular fracture surgery were randomly assigned to the remifentanil group (Group R, n = 35) or the dexmedetomidine group (Group D, n = 35). The primary outcomes were preoperative pain scores caused by jaw movement; haemodynamic response; intubation score; and side effects, such as the incidence of oxygen desaturation and muscle rigidity. Other side effects, such as tachycardia, bradycardia, hypertension and hypotension, were also compared.

RESULTS

Preoperative pain scores caused by jaw movement were significantly high for both groups, but there were no statistically significant differences between the groups. The incidence of oxygen desaturation and muscle rigidity was significantly lower in Group D than in Group R (p = 0.025). No significant differences existed between the groups in terms of intubation score, haemodynamics, and other side effects (p > 0.05).

DISCUSSION

Dexmedetomidine and remifentanil had equal effectiveness on the control of haemodynamic response due to mask ventilation and intubation in patients with mandibular fractures. However, at the doses used in this study, dexmedetomidine had a significant advantage over remifentanil in terms of respiratory stability.

A different placement of the stone; rhinolithiasis

INTRODUCTION

Rhinolithiasis is a rare disease and formed by mineralization in the nasal cavity. Precipitated calcareous material on intranasal foreign substances forms the rhinoliths. It is start time could have since childhood.

MATERIALS AND METHODS

In this article, we present eight cases of rhinolithiasis who admitted to our Clinic between January 2001 and December 2010 with unilateral chronic nasal discharge, nasal obstruction and oral malodor.

CONCLUSIONS

Rhinolithiasis mostly manifests itself with unilateral purulent rhinorrhea, nasal obstruction and facial pain symptoms. We aimed to discuss these entity with similar cases in the literature.

Multiple dural arteriovenous fistulas involving the cavernous sinus, transverse sinus, sigmoid sinus and spinal drainage: CT angiography findings in 14-year-old boy

Dural arteriovenous fistulas (DAVF) are rare and constitute 10% to 15% of all intracranial arteriovenous malformations. Only few cases of DAVFs are reported in children. Here is the first case report describing CT angiographic findings in a 14 year old child having multiple DAVFs involving spinal canal, both cavernous and cerebral sinuses.

The incidence of non-proliferative and precancerous lesions of reduction mammoplasty: evaluation of 273 cases

BACKGROUND

Reduction mammoplasty (RM) is one of the most commonly performed plastic surgery procedures to treat symptomatic macromasty or to correct asymmetry. Occult breast carcinomas were rarely defined in RM specimens. There are few studies aiming to define the incidence of non-proliferative and precancerous lesions.

MATERIAL AND METHODS

We evaluated the pathological findings of the RM specimens that have been submitted to our Center for the last 6 years (2005-2011).

RESULTS

A total of 273 cases with bilateral RM were enrolled to the study. Of them, 229 cases had pathological changes. Eight cases (2.9%) had atypical ductal/lobular hyperplasia. One case (0.3%) had lobular carcinoma in situ; however, no invasive breast carcinoma was detected. Other pathological findings included fibrocystic changes, fibrosis, adenosis, fibroadenoma (without complex features), mastitis and duct ectasia.

CONCLUSIONS

Pathological examination of the RM specimens is quite important to define the lesions precancerous of breast carcinoma. Unknown occult breast lesions could be identified and early interventions may be taken into account.

Vaccination coverage in the South-East Anatolian Project (SEAP) region and factors influencing low coverage

OBJECTIVES

To determine the vaccination coverage of children living in the South-east Anatolian Project (SEAP) region; whether the vaccination coverage was similar to formal reports, other studies and other countries; and which factors influence vaccination, in order to indicate how vaccination coverage can be improved.

STUDY DESIGN

A descriptive cross-sectional study conducted in nine provinces of the SEAP region in order to determine public health problems and their causes.

METHODS

A population-based sample of 1150 houses was selected from rural and urban areas of the SEAP region and visited by the researchers. Questionnaires were applied in 2001 and 2002.

RESULTS

In the SEAP region, only 30% of children had received a complete set of vaccines. The vaccination coverage was 76.7% for Bacille Calmette-Guérin; 62.0% for the third doses of diphtheria, tetanus toxoid, pertussis and polio vaccine; 62.7% for measles; 44% for the third dose of hepatitis B vaccine in children aged 12-23 months; and 13.3% for the second dose of tetanus toxoid in women who gave birth in the last 5 years. In logistic regression analysis, residence type, number of siblings, birth interval, follow-up visits of midwives, and maternal level of education were found to influence whether children were completely vaccinated.

CONCLUSIONS

The findings of this study indicate that vaccination coverage is not acceptable in the SEAP region. Efforts must focus on family planning services, education of women, follow-up visits and strengthening health facilities, especially in rural regions, to improve vaccination.

Behaviour of Toxoplasma gondii RH Ankara strain tachyzoites during continuous production in various cell lines

Toxoplasma gondii is an obligate intracellular protozoan parasite. The objective of the present study was to examine the behaviour of Toxoplasma gondii RH Ankara strain tachyzoites in a cell culture environment. The study represents the first step in determining whether T. gondii RH Ankara strain tachyzoites, grown in cell culture, are of sufficient quality to allow cessation of in vivo tachyzoite production for diagnostic assays. In the present study, T. gondii RH Ankara strain tachyzoites were continuously produced in myeloma X63.Ag8.653, HeLa, Hep-2, and Vero cell cultures for 2 months. The average size of the tachyzoites was 3×5·7 μm prior to the first inoculation but after continuous production, a marked decrease was noted in average tachyzoite size. The smallest tachyzoite size, was 1×2·1 μm after 2 months, in myeloma cell cultures even though the yield of tachyzoites increased. With other cell cultures, tachyzoite yields were not as high as myeloma cell culture although decrease in size was less. The smallest decrease in tachyzoite size, averaging 2×3·8 μm after 2 months, was observed in tachyzoites produced in HeLa cell cultures. A virulence assay in small groups of BALB/c mice, using tachyzoites derived from cell cultures, was also conducted. The preliminary results of the virulence assay suggest that as the size of the tachyzoites decreased, the virulence in mice decreased. Future research will focus on the effect of the size of cell culture-derived T. gondii RH Ankara strain tachyzoites on the virulence, protein expression, and the reliability of diagnostic assays. Ultimately, the behaviour of tachyzoites from various T. gondii strains will be observed in cell culture to determine if size is altered.

Production of monoclonal antibodies against a 19-kD recombinant Plasmodium vivax MSP1 for detection of P. vivax malaria in Turkey

Plasmodium vivax malaria, which is transmitted to humans by mosquitoes, is one of the most important parasitic diseases in Turkey. The major protein on the surface of asexual erythrocytic stage merozoites of P. vivax (Pv) is 200 kD and called major merozoite surface protein-1 (PvMSP1). Polyclonal antibodies against the 19-kD C-terminal fragment of PvMSP1 (PvMSP1(19)) are protective in monkey models of P. vivax and associated with protection in field studies. In this research, monoclonal antibodies were produced against PvMSP1(19). A total of 214 IgG(1) antibody-releasing hybridomas were obtained and three monoclonal antibodies were produced (PvMSP1(19).1, PvMSP1(19).2, and PvMSP1(19).3) and selected for further study. They have now been purified from ascitic fluid on a Staphylococcus protein A affinity column. These are the first monoclonal antibodies produced against P. vivax in Turkey and the first monoclonal antibodies produced against this recombinant PvMSP1(19) in the world. The monoclonal antibodies will be used to study the epidemiology of P. vivax in patients with malaria in Turkey, and to develop better strategies for early diagnosis and treatment of the disease in our population.

Endometrial laser intrauterine thermotherapy: the first series of 100 patients observed for 1 year

OBJECTIVE

To describe a new instrument (GyneLase) that offers a new approach (endometrial laser intrauterine thermal therapy [ELITT]) to treatment of menorrhagia and to evaluate the efficacy of ELITT in the management of dysfunctional uterine bleeding.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

100 premenopausal women with dysfunctional uterine bleeding were observed for 1 year.

INTERVENTION(S)

Intrauterine laser thermotherapy with a diode laser.

MAIN OUTCOME MEASUREMENT(S)

Amenorrhea rate after 1 year.

RESULT(S)

The amenorrhea rate after 1 year of follow-up was 71%, and the rate of amenorrhea/severe hypomenorrhea rate was >90%; these rates are much higher than those in the literature after such procedures as electrosurgery or intrauterine thermal balloon therapy. The ELITT procedure is an inherently safe and simple alternative, providing controlled and effective treatment of the entire endometrium. In contrast to traditional endometrial ablation using a neodymium yttrium-aluminum-garnet laser, the ELITT procedure does not require intensive training or hysteroscopic control; it is also far less risky, because the power used per unit area is 1,000 times lower.

CONCLUSION(S)

The ELITT procedure is a new nonhysteroscopic technique for endometrial ablation. The technique is very safe and offers the highest amenorrhea rate to date in the literature.

Endometrial laser intrauterine thermo-therapy (ELITT): a revolutionary new approach to the elimination of menorrhagia

Various non-hysteroscopic procedures have been developed in the attempt to treat dysfunctional uterine bleeding that fails to respond to medical treatment efficiently and easily. Among these procedures is low-dose laser radiation of the endometrium with the diode source, which is characterized by the highest incidence of amenorrhea.

Effect of octreotide (Sandostatin 201-995) on bile flow and bile components

Octreotide (Sandostatin 201-995) has an inhibitory effect on gastric, intestinal, and pancreatic secretions and hepatic and splachnic blood flow. We examined the effects of octreotide on bile flow and bile components in 10 patients with T-tube choledochostomy. A Fogarty balloon catheter was inserted distal to the T-tube of these patients for measurement of bile flow and bile components. Bile samples were obtained to analyze bile acid, phospholipid, lipoprotein, and cholesterol, and bile flow measurements were performed every 15 min for a period of 90 min before study and after normal saline and octreotide administrations. While octreotide had an inhibitory effect on bile flow, the concentrations of bile acid, phospholipid, and lipoprotein in bile were increased with octreotide.

Humoral immune responses against Plasmodium vivax MSP1 in humans living in a malaria endemic area in Flores, Indonesia

The aim of this study was to evaluate the relationship among age, parasitemia status, spleen size, hematocrit, and antibody levels to Plasmodium vivax merozoite surface protein 1 (MSP1) in individuals chronically exposed to P. vivax. Subjects were recruited from the population of three adjacent villages on the Island of Flores in Indonesia where malaria transmission is hyperendemic and tropical splenomegaly syndrome is highly prevalent. Subjects were evaluated for spleen size, hematocrit, presence of parasitemia, and presence of antibodies to a recombinant peptide consisting of 90 amino acids from the carboxy terminus of MSP1. Fifty-seven percent of 2-4 year olds, 45% of 5-9 years old, and 7% of > or = 15 years old were parasitemic; 99% of the > or = 15 years old had splenomegaly, and 31% of them had Hackett 4 or 5 spleens. The frequency of antibody positivity to MSP1 antigen in ELISA increased with age reaching a maximum of 89% in > or = 20 years old. The frequency of antibody positivity to MSPI also increased with spleen size, and with a decline in the prevalence of parasitemia.

Monoclonal antibodies of three different immunoglobulin G isotypes produced by immunization with a synthetic peptide or native protein protect mice against challenge with Plasmodium yoelii sporozoites

Passive transfer of monoclonal antibodies (MAbs) against malaria circumsporozoite (CS) proteins protects animals against malaria. Active immunization with synthetic or recombinant peptides induces a level of polyclonal antibodies to sporozoites comparable to those found after passive immunization but does not provide comparable protection. In the Plasmodium yoelii system, synthetic or recombinant peptide-induced antibodies have never been shown to protect. The current studies were designed to determine whether immunogen structure (native protein versus synthetic peptide) or immunoglobulin G (IgG) subclass of antibodies was responsible for the absolute differences between protective, passively transferred MAbs and nonprotective, actively induced polyclonal antibodies. In this study we produced two MAbs, QGP-S1 (IgG1) and QGP-S2 (IgG2b), by immunization with a synthetic peptide based on the P. yoelii CS major repeat, (QGPGAP)4, conjugated to keyhole limpet hemocyanin. These MAbs were compared tp NYS1 (IgG3), an anti-CS protein MAb previously produced by immunization with irradiated P. yoelii sporozoites, which recognizes (QGP GAP)2. QGP-S1 and QGP-S2 passively transferred protection. However, when compared with NYS1, there was a hierarchy of protection, NYS1 > QGP-S1 > QGP-S2. There was no correlation between antibody level at challenge as determined by immunofluorescent antibody test against sporozoites or enzyme-linked immunosorbent assay against (QGPGAP)2 or apparent antibody avidity for (QGPGAP)2 by sodium thiocyanate elution assay. The data demonstrate that a synthetic peptide can induce protective antibodies and that a specific antibody subclass is not required for protection. Work to determine whether antibody affinity or fine specificity can explain the hierarchy of protection among the MAbs is under way.