NIMG-11. VOLUMETRIC ENDPOINTS IN DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG): COMPARISON TO CROSS-SECTIONAL MEASURES AND CORRELATION WITH OUTCOMES

INTRODUCTION Cross-sectional tumor measures are used as endpoints in clinical trials of DIPG, but may not capture meaningful changes in disease burden. Volumetric measures may provide a more accurate assessment of tumor growth. We measured the correlation between cross-sectional and volumetric measures and compared their prognostic impact to better understand response evaluation in DIPG. METHODS Patients from the International DIPG Registry with diagnostic and post-radiation MRIs were included. Utilizing mint LesionTM software, tumors were manually contoured by an experienced pediatric neuro-radiologist to extrapolate cross-sectional product (CP) and volume measures. Correlation between CP and volume was assessed by linear regression. Landmark analyses were performed to determine differences in overall survival (OS) (via log-rank) between patients classified as progressive disease (PD) versus non-PD according to CP and volumetric measurements at one-, three-, and five-months post-radiation. Imaging consistent with pseudoprogression was designated non-PD. Hazard ratios (HR) for survival after these timepoints were calculated by Cox regression. RESULTS A total of 317 MRIs from 46 patients were analyzed. When comparing change from smallest previous tumor size, CP increase of 25% (PD by RAPNO) correlated with volume increase of 28% (R2=0.685). There was no difference in OS between patients classified as PD versus non-PD by CP at one-month, three-months, or five-months post-radiation (p >0.05). However, significant differences in OS were observed between patients classified as PD versus non-PD by volume (28% increase) at one-month (2.7 vs. 12.8 months, p=0.005), three-months (1.9 vs. 10.7 months, p=0.036), and five-months post-radiation (3.7 vs. 9.1 months, p=0.023). PD by volume, but not by CP, was predictive of survival at all timepoints (HR: 5.0, 2.4, 2.4). CONCLUSIONS Volumetric assessments of PD correlated better with survival than CP at all post-radiation timepoints. Tumor volume likely represents a more accurate, prognostically-relevant measure of disease burden that deserves investigation in future DIPG trials.

Psychiatric, Emotional, and Brain Volumetric Footprints of Childhood Conduct in Healthy Young Adults

BackgroundConduct Disorder (CD) is defined as aggressive, antisocial, and rule-breaking behavior during childhood. Despite being the major risk factor for developing an antisocial personality disorder, nearly half the patients return to a nearly normal and healthy status. We aimed to identify psychiatric, emotional, and brain volumetric footprints of childhood CD in healthy young adults with a prior history of CD.MethodsWe recruited 156 healthy young adults from the Human Connectome Project: 78 with a prior history of CD (CC) and 78 age-, gender-, and education-matched subjects with no history of CD (HC). Psychiatric, emotional, and personality assessments were based on the Adult Self Report, NIH toolbox emotion battery and Penn emotion recognition task, and NEO-Five Factor Inventory. We acquired MRI volumetric measures and hippocampal and amygdala segmentation values using FreeSurfer. Between-group differences and associations between the assessments and the hippocampal or amygdala nuclei were assessed statistically.ResultsAfter Benjamini-Hochberg correction, we found higher anger aggression, antisocial personality problems, aggressive and rule-breaking behaviors, externalizing, and lower agreeableness in the CC group. No differences between volumetric measures were noted. Interestingly, only in the CC group, better angry face recognition was associated with larger volumes of several hippocampal nuclei.DiscussionDespite having no notable MRI volumetric differences, healthy young adults with a prior history of CD still exhibit some forms of antisocial-like behavior, without evidence of emotional recognition disturbances. Moreover, hippocampal-related learning may provide a compensatory mechanism for angry face recognition deficits in CD, playing a potential protective role.

Three-dimensional optoacoustic imaging of nailfold capillaries in systemic sclerosis and its potential for disease differentiation using deep learning

The autoimmune disease systemic sclerosis (SSc) causes microvascular changes that can be easily observed cutaneously at the finger nailfold. Optoacoustic imaging (OAI), a combination of optical and ultrasound imaging, specifically raster-scanning optoacoustic mesoscopy (RSOM), offers a non-invasive high-resolution 3D visualization of capillaries allowing for a better view of microvascular changes and an extraction of volumetric measures. In this study, nailfold capillaries of patients with SSc and healthy controls are imaged and compared with each other for the first time using OAI. The nailfolds of 23 patients with SSc and 19 controls were imaged using RSOM. The acquired images were qualitatively compared to images from state-of-the-art imaging tools for SSc, dermoscopy and high magnification capillaroscopy. The vascular volume in the nailfold capillaries were computed from the RSOM images. The vascular volumes differ significantly between both cohorts (0.216 ± 0.085 mm3 and 0.337 ± 0.110 mm3; p < 0.0005). In addition, an artificial neural network was trained to automatically differentiate nailfold images from both cohorts to further assess whether OAI is sensitive enough to visualize anatomical differences in the capillaries between the two cohorts. Using transfer learning, the model classifies images with an area under the ROC curve of 0.897, and a sensitivity of 0.783 and specificity of 0.895. In conclusion, this study demonstrates the capabilities of RSOM as an imaging tool for SSc and establishes it as a modality that facilitates more in-depth studies into the disease mechanisms and progression.