Tumor Characteristics Research Articles

Minimising warm ischaemia time during robot-assisted partial nephrectomy. A video-based assessment of tumour excision, kidney reconstruction and intermediate time.

Surgical video review is an emerging tool for assessing patient outcomes, especially in complex surgeries such as robot-assisted partial nephrectomy (RAPN). Assessing and measuring warm ischaemia time (WIT) during RAPN by dividing it into the time used for tumour excision time (ExcT), time used for kidney reconstruction time (RecT) and intermediate time (IntT) has not been performed before. This study aimed to analyse the factors that can influence all surgical times and assess their impact on positive surgical margins (PSMs) and complication rates. We evaluated 32 surgical video recordings from patients undergoing RAPN and measured WIT, ExcT, RecT and IntT with a stopwatch. Factors such as tumour characteristics and surgeon experience were also recorded. SPSS software was used to identify the predictors for all surgical times and to correlate ExcT with PSM and RecT with complication rate. We recorded a median WIT of 1,048 s (17 min and 28 s). The median of ExcT, RecT and IntT was 398 s (37.1% of WIT), 518 s (46.7% of WIT) and 180 s (16.2% of WIT), respectively. We found a significant correlation (P < 0.001) between R.E.N.A.L. score and all surgical times. No correlation was found between ExcT and PSM (P = 0.488) and between RecT and the probability of developing complications (P = 0.544). Tumour morphology influences all surgical times, and surgeon experience influences only ExcT. We observed a short RecT during RAPN though at the cost of increased ExcT, and we believe that improving surgical experience, especially for the excision of more complex tumours, can reduce WIT during RAPN.

Growth hormone increase by luteinizing hormone-releasing hormone reflects gonadotroph-related characteristics in acromegaly.

We previously showed the clinical characteristics of acromegaly with a paradoxical growth hormone (GH) response to oral glucose or thyrotropin-releasing hormone. However, the clinical characteristics of acromegaly with an increased GH response to luteinizing hormone-releasing hormone (LHRH responders) remain unclear. The aim of the present study was to evaluate the clinical characteristics, especially gonadotroph-related characteristics of LHRH responders in acromegaly. The clinical characteristics of 33 LHRH responders and 81 LHRH nonresponders were compared. No differences in age, sex or basal serum levels of GH, insulin-like growth factor-1 (IGF-1), and gonadotropin were observed between the two groups. Steroidogenic factor 1 (SF-1), gonadotropin-releasing hormone receptor (GnRHR), and LH expression was more frequently observed in LHRH responders (P < 0.05). In addition, a greater increased rate of GH after LHRH loading, and the proportion of GnRHR and gonadotropin expression was observed in pituitary tumor with SF-1 expression than that without the expression (P < 0.01). LHRH responders showed a greater GH decrease in the octreotide test and a greater IGF-1 decrease after first-generation somatostatin ligand than LHRH nonresponders (P < 0.05). Furthermore, the proportion of hypointense pituitary tumors on T2-weighted magnetic resonance imaging and tumors with densely granulated type was higher in LHRH responders than in LHRH nonresponders, respectively (P < 0.05). No difference between the two groups was observed in either somatostatin receptor 2 or 5 expression. The increased GH response to LHRH is associated with the gonadotroph-related characteristics. This response may reflect the biological characteristics of somatotroph tumors.

The feasibility of visualizing and quantifying muscle changes in postoperative oral cancer patients using Quantitative Muscle Ultrasound (QMUS).

Quantitative muscle ultrasound (QMUS) is a patient friendly tool for examining orofacial muscles. Resection of tissue can have an effect on the architecture and function of these muscles. The aim of this study is to investigate the feasibility of visualizing and quantifying muscle changes in postoperative oral cancer patients and to relate the findings to tumor and patient characteristics. Adult patients with a resected first primary pT1 or T2 oral squamous cell carcinoma, at least one year post operatively, where included. Ultrasound data were collected of the geniohyoid muscle, digastric muscles, masseter muscle, transverse muscle and genioglossus muscle. Ultrasound images were labeled as clearly visible, questionable or unclear. Of the clear muscles, echogenicity and muscle thickness were measured. 37 patients were included. The masseter muscle was clearly visible in all ultrasound images, both intrinsic tongue muscles had the lowest visibility (45.9%). There was a significant correlation between visibility and tumor localization for the genioglossus (p = 0.029). Age correlated with the visibility of the genioglossus muscle, BMI with the genioglossus and transverse muscles. Echogenicity and muscle thickness of the clearly identified muscles did not differ from normative values. QMUS of orofacial muscles is feasible in postoperative oral cancer patients with relatively small tumor sizes. Tongue resections negatively affected the visibility of the two intrinsic tongue muscles. These preliminary results for particular muscles indicate that the use of ultrasound might be promising in oral cancer patients to help determine targeted goals in post-operative rehabilitation.

Clusters of resilience and vulnerability: executive functioning, coping and mental distress in patients with diffuse low-grade glioma

PurposeDiffuse low-grade gliomas (dLGG) often have a frontal location, which may negatively affect patients’ executive functions (EF). Being diagnosed with dLGG and having to undergo intensive treatment can be emotionally stressful. The ability to cope with this stress in an adaptive, active and flexible way may be hampered by impaired EF. Consequently, patients may suffer from increased mental distress. The aim of the present study was to explore profiles of EF, coping and mental distress and identify characteristics of each profile.Methods151 patients with dLGG were included. Latent profile analysis (LPA) was used to explore profiles. Additional demographical, tumor and radiological characteristics were included.ResultsFour clusters were found: 1) overall good functioning (25% of patients); 2) poor executive functioning, good psychosocial functioning (32%); 3) good executive functioning, poor psychosocial functioning (18%) and; 4) overall poor functioning (25%). Characteristics of the different clusters were lower educational level and more (micro)vascular brain damage (cluster 2), a younger age (cluster 3), and a larger tumor volume (cluster 4). EF was not a distinctive factor for coping, nor was it for mental distress. Maladaptive coping, however, did distinguish clusters with higher mental distress (cluster 3 and 4) from clusters with lower levels of mental distress (cluster 1 and 2).ConclusionFour distinctive clusters with different levels of functioning and characteristics were identified. EF impairments did not hinder the use of active coping strategies. Moreover, maladaptive coping, but not EF impairment, was related to increased mental distress in patients with dLGG.

The Five Periampullary Cancers, not Just Different Siblings but Different Families: An International Multicenter Cohort Study.

Cancer arising in the periampullary region can be anatomically classified in pancreatic ductal adenocarcinoma (PDAC), distal cholangiocarcinoma (dCCA), duodenal adenocarcinoma (DAC), and ampullary carcinoma. Based on histopathology, ampullary carcinoma is currently subdivided in intestinal (AmpIT), pancreatobiliary (AmpPB), and mixed subtypes. Despite close anatomical resemblance, it is unclear how ampullary subtypes relate to the remaining periampullary cancers in tumor characteristics and behavior. This international cohort study included patients after curative intent resection for periampullary cancer retrieved from 44 centers (from Europe, United States, Asia, Australia, and Canada) between 2010 and 2021. Preoperative CA19-9, pathology outcomes and 8-year overall survival were compared between DAC, AmpIT, AmpPB, dCCA, and PDAC. Overall, 3809 patients were analyzed, including 348 DAC, 774 AmpIT, 848 AmpPB, 1,036 dCCA, and 803 PDAC. The highest 8-year overall survival was found in patients with AmpIT and DAC (49.8% and 47.9%), followed by AmpPB (34.9%, P < 0.001), dCCA (26.4%, P = 0.020), and finally PDAC (12.9%, P < 0.001). A better survival was correlated with lower CA19-9 levels but not with tumor size, as DAC lesions showed the largest size. Despite close anatomic relations of the five periampullary cancers, this study revealed differences in preoperative blood markers, pathology, and long-term survival. More tumor characteristics are shared between DAC and AmpIT and between AmpPB and dCCA than between the two ampullary subtypes. Instead of using collective definitions for "periampullary cancers" or anatomical classification, this study emphasizes the importance of individual evaluation of each histopathological subtype with the ampullary subtypes as individual entities in future studies.

NFS-02. MEDULLOBLASTOMAS WITH ELP1 PATHOGENIC VARIANTS: A WEAKLY PENETRANT SYNDROME WITH A RESTRICTED SPECTRUM IN A LIMITED AGE WINDOW

Abstract BACKGROUND Medulloblastomas (MB) Sonic hedgehog (SHH) subtype are associated with a cancer predisposition syndrome (CPS) in about 15% of cases, the most frequent being related to ELP1 pathogenic variant (PV). The aim of our study is to better evaluate penetrance of this CPS and detail the characteristics of the related tumors. METHODS Twenty-nine ELP1-mutated MB identified in France were retrospectively reviewed. Molecular characteristics of the tumor and clinical features of the patients were collected; whenever possible, the germline DNA from patients and their relatives were sequenced. RESULTS All patients (sex ratio 16/13) presented with SHH-MB, mostly nodular desmoplastic (n=20/28), between 3 and 15 years of age (median 7.3). All mutations are found in the germline when a constitutional DNA sample was available (n=26). Most tumors (93%) showed a biallelic inactivation of PTCH1, other recurrent alterations concerned the TP53 pathway (including 1 somatic TP53 VP) and activation of MYCN/MYCL signaling. We observed that ELP1-mutated MB behave as sporadic cases, with similar distribution within clinical and molecular risk groups of MB, similar outcomes (5y-OS = 85%) and no unusual side effects of treatments. Three patients developed a second tumor (2 high-grade gliomas and 1 thyroid carcinoma) within the irradiation fields. All germline PV were inherited from one asymptomatic parent (11 trio). No specific morphological features were mentioned. Only two index cases from the 29 French patients had a previous familial history of MB (occurring in a cousin), with many asymptomatic carriers. Except the MB, no other cancer was significantly associated with the ELP1 PV. CONCLUSIONS the low penetrance, the ‘at risk’ age window limited to childhood and the narrow tumor spectrum, question the actual benefit of genetic screening in these patients and their family. Our results suggest restricting ELP1 germline sequencing to patients with MB, depending on the parents’ request.

CP-14. VOLUMETRIC ANALYSIS OF PAEDIATRIC CRANIOPHARYNGIOMAS: CLINICAL-RADIOLOGICAL CORRELATION STUDY

Abstract BACKGROUND Craniopharyngioma are heterogeneous hypothalamopituitary tumours with solid and cystic components which have a distinct natural history. Neuroimaging follow-up and the definition of progressive disease is challenging due to unpredictable growth of the inflammatory cystic component. METHODS This multicentre retrospective observational study aimed to describe the clinical-radiological correlation of craniopharyngiomas at two paediatric neurosurgery units (GOSH,UK and USP,Brazil). Craniopharyngiomas treated over a 20-year period were identified and standardized clinical outcomes recorded. Baseline MRIs were reviewed and volumetric T1-weighted images segmented by a board-certified paediatric neuroradiologist. RESULTS Of 123 patients, 92 baseline MRIs were available for image analysis (USP=32; GOSH=60). No differences between series were identified in either demography (mean age: USP=9.2±4.6; GOSH=8.2±4.1 years) or tumour characteristics, with tumours being predominantly cystic (USP=75%; GOSH=76%), localised to the sellar/suprasellar region (USP=84%; GOSH: 88%), and on pre-chiasmatic (USP=34%; GOSH=22%) or retro-chiasmatic (USP=59%; GOSH=67%) locations. Pre-chiasmatic tumours were associated with an increased prevalence of visual symptoms at presentation (p=0.006) and worse recovery of visual acuity at long-term follow-up (p=0.021). Regarding volumetric analysis, mean volumes were 16.6±25.1cm3 for the cystic component and 38.3±10cm3 for the solid component. Volumes of the solid and cystic components had no correlation with each other. Larger cystic tumour volumes were correlated with a greater prevalence of diabetes insipidus at presentation (p=0.06). Larger solid tumours were significantly related to younger ages (p=0.02) and had worse PFS in our series. In terms of long-term outcomes, high volume cystic tumours were related to worse hypothalamic outcomes. In multivariate analysis (n=92), Paris classification did not predict long-term outcomes. CONCLUSIONS Volumetric analysis of craniopharyngiomas showed significant correlation with the onset of diabetes insipidus and hypothalamic long-term outcomes. Larger cystic craniopharyngioma were more common in younger patients. The Paris classification did not predict long-term outcomes in multivariate analysis.

Magnitude and Temporal Variations of Socioeconomic Inequalities in the Quality of Life After Early Breast Cancer: Results From the Multicentric French CANTO Cohort.

Socioeconomic status (SES) influences the survival outcomes of patients with early breast cancer (EBC). However, limited research investigates social inequalities in their quality of life (QoL). This study examines the socioeconomic inequalities in QoL after an EBC diagnosis and their time trends. We used data from the French prospective multicentric CANTO cohort (ClinicalTrials.gov identifier: NCT01993498), including women with EBC enrolled between 2012 and 2018. QoL was assessed using the European Organisation for Research and Treatment of Cancer QoL Core 30 questionnaire (QLQ-C30). summary score at diagnosis and 1 and 2 years postdiagnosis. We considered three indicators of SES separately: self-reported financial difficulties, household income, and educational level. We first analyzed the trajectories of the QLQ-C30 summary score by SES group. Then, social inequalities in QLQ-C30 summary score and their time trends were quantified using the regression-based slope index of inequality (SII), representing the absolute change in the outcome along socioeconomic gradient extremes. The analyses were adjusted for age at diagnosis, Charlson Comorbidity Index, disease stage, and type of local and systemic treatment. Among the 5,915 included patients with data on QoL at diagnosis and at the 2-year follow-up, social inequalities in QLQ-C30 summary score at baseline were statistically significant for all SES indicators (SIIfinancial difficulties = -7.6 [-8.9; -6.2], SIIincome = -4.0 [-5.2; -2.8]), SIIeducation = -1.9 [-3.1; -0.7]). These inequalities significantly increased (interaction P < .05) in year 1 and year 2 postdiagnosis, irrespective of prediagnosis health, tumor characteristics, and treatment. Similar results were observed in subgroups defined by menopausal status and type of adjuvant systemic treatment. The magnitude of preexisting inequalities in QoL increased over time after EBC diagnosis, emphasizing the importance of considering social determinants of health during comprehensive cancer care planning.

Soft tissue sarcomas of the proximal adductor area of the thigh: Indications, results and complications at medium follow-up in a series of 43 surgically treated patients

IntroductionWhen Soft Tissue Sarcomas are localized in the groin area, they pose specific challenges due to their proximity to important structures. These tumors exhibit elevated complication rates and a higher local recurrence rate compared to their locations in other limbs. The objective of this paper is to analyze a series of patients affected by soft tissue sarcomas in the adductor area of the proximal thigh. The analysis aims to elucidate the epidemiology, diagnostic and therapeutic approaches, complications, and outcomes. Additionally, the study seeks potential prognostic factors and to determine patients at a heightened risk of postoperative complications. Patients and methodsall patients who underwent surgeries for primary soft tissue sarcomas of the adductor area between October 2006 and March 2022 in a tertiary research hospital were valued. Epidemiology, tumor characteristics and therapeutic approaches were analyzed to identify risk factors for complications and local recurrences; survival was considered a secondary outcome. ResultsThe series comprised 43 patients, 26 males and 17 females, with an average age of 63.3 years. The most frequent histology was liposarcoma, followed by undifferentiated forms. All patients reported the presence of masses, with associated pain in 27.9% of cases. Limb-sparing surgery was performed in 86.0% of cases. Early and late complications were experienced by 34.9% and 20.0% of patients, respectively, with wound dehiscence being the most frequent problem. The recurrence rate was 9.3%, with no recurrences observed in low-grade patients. At an average follow-up of 51 months, 18 patients (41.9%) were alive, two of which with distant metastases. ConclusionThe present series provides evidence that when Soft Tissue Sarcomas localized in the groin area are managed in specialized centers, the rates of recurrence and complications are not significantly different from those observed in other anatomical sites.

LGG-03. PREDICTIVE VALUE OF ACQUIRED NYSTAGMUS FOR PEDIATRIC BRAIN TUMOR ASSOCIATED VISUAL IMPAIRMENT: A RETROSPECTIVE STUDY

Abstract BACKGROUND Visual impairment (VI), defined as visual acuity (VA) loss or visual field (VF) defects, is common in pediatric brain tumors of the optic pathway and may impact the quality of life. VI is a challenge to establish, especially in young children. However, pediatric brain tumor patients might concurrently have acquired nystagmus (AN), which can easily be observed. The aim of this study was to investigate whether AN is predictive of VI in pediatric brain tumor patients. If correlated, AN could be an early warning sign for brain tumor related VI, warranting MRI scanning to prevent further visual deterioration, thus decreasing morbidity and mortality. METHODS Data on tumor characteristics, VA (in LogMAR), VF, (type of) AN and other ophthalmic investigations were collected from the medical records of pediatric brain tumor patients in the Máxima Pediatric Brain Tumor Ophthalmology cohort (MP-BT-O cohort). These characteristics between children with (nystagmus group) and without (control group) AN were compared to determine the predictors of VI. RESULTS The MP-BT-O cohort consists of 389 children (≤18y) with a brain tumor who had visual assessment, 95 children had AN (24.4%). The mean best corrected visual acuity (BCVA) was 0.10 LogMAR [CI 0.06-0.14] in the control and 0.50 LogMAR [CI 0.35-0.66] in the nystagmus group (p&amp;lt;0.001). Nystagmus type was found to be a significant predictor of VI (p&amp;lt;0.001). Specifically horizontal AN (a decrease in BCVA of 0.75 LogMAR, p&amp;lt;0.001) and mixed AN (a decrease in BCVA of 0.61 LogMAR, p&amp;lt;0.001) were independent predictors of VI, corrected for tumor location (p=0.04) and age at diagnosis (an increase in BCVA of -0.02 LogMAR per year, p&amp;lt;0.001). CONCLUSIONS Acquired nystagmus, especially horizontal and mixed nystagmus, is an independent predictor of VI in pediatric brain tumor patients and should be interpreted as a warning sign for the presence of VI.

Purely Off-Clamp Sutureless Robotic Partial Nephrectomy for Novice Robotic Surgeons: A Multi-Institutional Propensity Score-Matched Analysis.

Objectives: To compare perioperative outcomes of patients treated with sutureless off-clamp robotic partial nephrectomy (sl-oc RAPN) by either a novice or an expert robotic surgeon at two different institutions. Methods: Data concerning two continuous series of patients with cT1-2N0M0 renal tumors treated with sl-oc RAPN either by a novice or an expert surgeon were extracted from prospectively populated institutional databases over the last 4 years. Perioperative outcomes as well as the baseline characteristics of patients and tumors were compared by using χ2 and Mann-Whitney tests for categorical and continuous variables, respectively. A 1:1 propensity match score analysis (PMSa) generated two homogeneous cohorts. Logistic regression analysis was performed to assess predictors of trifecta outcomes, defined as negative surgical margins, no Clavien-Dindo ≧ 3 grade complications, and no ≧ 30% postoperative eGFR reduction. Results: Overall, 328 patients were treated by an expert surgeon, while 40 were treated by a novice surgeon. After PMSa analysis, two cohorts of 23 patients each were generated, homogeneous for all baseline variables (p ≥ 0.07). Hospital stay was the only significantly different outcome observed between the two groups (5 days vs. 2 days; p < 0.001). No statistically significant differences were recorded when comparing trifecta outcomes (expert: 100% vs. novice: 87%; p = 0.07). In the logistic regression analysis, no statistically significant predictors of trifecta outcomes were recorded. Conclusions: sl-oc RAPN is a feasible and safe nephron sparing technique, even when performed by a novice robotic surgeon.

EPID-08. PEDIATRIC GLIOMA IN INDONESIA: CLINICAL PROFILES AND OUTCOMES

Abstract BACKGROUNDS Gliomas are the most common form of pediatric brain tumor. The primary obstacle to optimizing pediatric brain tumor health services, particularly in LMICs, is the lack of comprehensive epidemiological data. We aim to compile comprehensive data on pediatric gliomas, focusing on clinical profiles and outcomes within a national general hospital in Indonesia. METHODS A retrospective observational longitudinal study was performed at Cipto Mangunkusumo National General Hospital, focusing on glioma patients’ profiles and outcomes, registered under the pediatric CNS tumor service from January 2022 to December 2023. RESULTS Out of 50 suspected glioma patients, 28 patients (56%) underwent biopsy, 28% underwent other modalities (brainstem location), 12% were scheduled for surgery but had already died, 2% were in a watchful waiting mode, and 2% were scheduled for surgery but were lost to follow-up. Glioma-confirmed patients were predominantly female (57.1%), with a mean age of 7.11 ± 4.98. Low-grade gliomas predominated at 57.1%, a trend we attribute to Cipto Mangunkusumo’s status as a referral national hospital, where low-grade glioma cases may have been managed more frequently at lower-level hospitals. The majority of tumors were supratentorial (53.6%) compared to infratentorial (39.3%) and supra-infratentorial (7.1%). The most common symptoms were seizures (25%), followed by headaches (21.4%), disequilibrium (14.3%), and vomiting (10.7%). Moreover, the latter three symptoms exhibited a longer mean delay between symptom onset and medical consultation, potentially impacting prognosis. In the last follow-up, higher-grade gliomas demonstrated a significantly higher mortality rate at 28.6% compared to low-grade gliomas at 3.6% (P &amp;lt; 0.001). CONCLUSION Given the variable clinical characteristics of glioma tumors, these results underscore the urgent need for comprehensive epidemiological data on pediatric gliomas in Indonesia, particularly regarding prognosis-related factors. Such data could serve as a crucial step towards future research and clinical strategies aimed at improving outcomes for children with gliomas.

IMG-10. IMAGING SUBTYPES OF PEDIATRIC LOW-GRADE GLIOMA ARE ASSOCIATED WITH DISTINCT MOLECULAR CHARACTERISTICS

Abstract BACKGROUND Pediatric low-grade gliomas (pLGGs) have diverse molecular subtypes with distinct prognoses, necessitating personalized treatments. We aimed to determine whether radiomic features of pLGGs co-segregate with molecular subtypes, establishing a proof-of-concept that distinct molecular aberrations could manifest in differentiable imaging features. METHODS Leveraging radiomic, genomic, and transcriptomic data from 201 pLGG patients from the Children’s Brain Tumor Network (CBTN), we identified imaging-based pLGG subtypes through their radiophenotypes. This involved investigating the association of imaging subtypes with 2021 WHO pLGG classifications and profiling transcriptional characteristics distinguishing pLGG clusters. We used principal component analysis and K-Means clustering on 881 radiomic features and incorporated clinical variables (age, sex, tumor location), and derived three imaging subtypes. RESULTS BRAF V600E mutations were mainly found in subtype 3, while BRAF::KIAA1549 fusion in subtype 1. To ascertain transcriptome pathways most closely associated with imaging-based subtypes, we applied a supervised machine learning model with elastic net logistic regression using a one-versus-rest strategy for each imaging cluster, considering the top 100 most variable pathways, identified through gene set enrichment and gene co-expression network analyses, molecular subtype, tumor location, age, sex, and race. The predictive accuracy (area under the receiver operating characteristic curve) of the model was 0.86 | 0.72 for imaging subtype 1, 0.93 | 0.71 for subtype 2, and 0.91 | 0.64 for subtype 3 in the training | testing sets. Notably, each imaging subtype exhibited distinct molecular mechanisms; subtype 1 showed up-regulation of oxidative phosphorylation, PDGFRB, and interleukin 4, 10, and 13 signaling, while subtype 3 was linked to histone acetylation and DNA methylation pathways, relating to BRAF V600E pLGGs. CONCLUSIONS Our radiogenomics study suggests that intrinsic molecular characteristics of tumors drive distinct imaging subgroups of pLGG, providing a basis for future multi-modal investigations that may better define progression and targetability of the disease.

MDB-91. MEDULLOBLASTOMA – MOLECULAR CHARACTERISTICS AND RADIOLOGICAL ASPECTS OF A BRAZILIAN COHORT FROM A SINGLE CENTER

Abstract BACKGROUND Four molecular subgroups of medulloblastoma are distinguished by their genomic, epidemiological, and prognostic characteristics: Wingless (WNT), Sonic hedgehog (SHH), Group 3 and Group 4. Genotypic classification permits individualized therapeutic planning based on risk stratification, thereby improving patient outcome. This study aims to characterize the epidemiological and molecular data of a cohort treated at a single Brazilian center, as well as to correlate the heterogeneous aspects of magnetic resonance imaging (MRI) with the molecular characteristics of this tumor. METHODS The study analyzed 47 medulloblastoma cases, treated at the children’s oncology reference institution of a middle-income country between 2011 and 2021. The medical records, radiological findings and the histological and molecular classification are reviewed. The images were evaluated by an experienced neuroradiologist, blinded to clinical and molecular information. RESULTS Thirty-two out 47 patients met the eligibility criteria and were analyzed. The frequency of molecular groups found was 6.25% Non-SHH/ Non-WNT, 12.50% WNT, 34.38% SHH, 3% Group 3 and 44 % Group 4. The analysis revealed tumor location, presence of hemorrhage/calcification, limits and enhancement patterns are significant for molecular group prediction. SHH shows a significant prevalence in the cerebellar hemisphere, lower presence of hemorrhage/calcification and an ill-defined tumor margins when compared with other subgroups. Group 4 showed significantly less enhancement. CONCLUSIONS In accordance with the frequency observed in studies on childhood medulloblastoma, our series found a significant prevalence of Group 4 and a lack of representativeness of Group 3. Despite the limitations, it was possible to identify radiological tumor characteristics that may predict the molecular subgroup and contribute to a more effective therapeutic approach, thereby reducing the incidence of post-surgical complications.

LGG-44. CLINICAL AND MOLECULAR TUMOR CHARACTERISTICS OF ‘HIGHER RISK’ PEDIATRIC LOW-GRADE GLIOMAS

Abstract BACKGROUND CNS WHO grade 1 pediatric low-grade gliomas (pLGGs) have an overall excellent survival. A small but relevant proportion of these patients, however, suffer from severe disease burden reflected in recurrent progression, metastasis or even death. To unravel clinicomolecular tumor characteristics that identify these ‘pLGG-higher risk’ patients we retrospectively analyzed clinical and molecular data of 223 patients from our center. METHODS All tumors were classified using histology, DNA methylation profiling and whole transcriptome analysis (RNA sequencing), with whole exome or panel DNA sequencing in a subset of cases, revealing a driver alteration in 100% of cases. Progression of disease was defined as continuous tumor growth upon treatment or need for multiple treatments. The effect of clinical and molecular variables on progression free survival was analyzed with the univariate and multivariate cox proportional hazard model. RESULTS The median follow-up of the entire cohort was 3,4 years. In univariate analyses the risk of progression significantly decreased with age (in years) at diagnosis (HR 0.92,p&amp;lt;0.001). For tumor location using hemispheric tumors as reference, chiasm/suprasellar LGGs showed a significantly higher risk of progression (HR 2.96,p&amp;lt;0.001). Type of molecular driver and sex was not associated with progression. In a multivariable model including age, location and driver, there was no longer a significant effect on progression for age but the effect of chiasm/suprasellar location remained intact. Furthermore, NF1 (HR 0.37,p0.02), and posterior fossa LGG (HR 0.24,p0.03) were both significantly associated with a lower risk of progression. CONCLUSIONS Our multivariate results show that the ‘pLGG-higher risk’ patients were characterized by a tumor in the chiasm/suprasellar location, while molecular driver (at least so far) did not affect risk of progression. Future work will focus on extending the cohort and integrating other multiomic data enabling to compose a prediction model for higher risk pLGG.

A Radiomic Approach for Evaluating Intra-Subgroup Heterogeneity in SHH and Group 4 Pediatric Medulloblastoma: A Preliminary Multi-Institutional Study.

Medulloblastoma (MB) is the most frequent malignant brain tumor in children with extensive heterogeneity that results in varied clinical outcomes. Recently, MB was categorized into four molecular subgroups, WNT, SHH, Group 3, and Group 4. While SHH and Group 4 are known for their intermediate prognosis, studies have reported wide disparities in patient outcomes within these subgroups. This study aims to create a radiomic prognostic signature, medulloblastoma radiomics risk (mRRisk), to identify the risk levels within the SHH and Group 4 subgroups, individually, for reliable risk stratification. Our hypothesis is that this signature can comprehensively capture tumor characteristics that enable the accurate identification of the risk level. In total, 70 MB studies (48 Group 4, and 22 SHH) were retrospectively curated from three institutions. For each subgroup, 232 hand-crafted features that capture the entropy, surface changes, and contour characteristics of the tumor were extracted. Features were concatenated and fed into regression models for risk stratification. Contrasted with Chang stratification that did not yield any significant differences within subgroups, significant differences were observed between two risk groups in Group 4 (p = 0.04, Concordance Index (CI) = 0.82) on the cystic core and non-enhancing tumor, and SHH (p = 0.03, CI = 0.74) on the enhancing tumor. Our results indicate that radiomics may serve as a prognostic tool for refining MB risk stratification, towards improved patient care.

IMG-20. IDENTIFICATION OF PRE-OPERATIVE IMAGING FEATURES ASSOCIATED WITH COGNITIVE IMPAIRMENT IN CHILDREN WITH BRAIN TUMOURS USING A LANGUAGE MODELLING SYSTEM COMBINED WITH MACHINE LEARNING ANALYSIS

Abstract BACKGROUND Cognitive impairments caused by paediatric brain tumours negatively impact future quality-of-life. Impairments of processing speed and working memory are important contributors to challenges these children encounter in education. Inconsistent image acquisition and poor imaging quality can restrict advanced radiomic analysis in historical datasets. We developed and refined a language modelling human image-analysis support system, passing data to specific machine learning techniques that can utilise datasets with many data points in a limited population. METHODS Medical records of children treated for brain tumours with surgery and radiotherapy in Manchester between 2000-2020 were reviewed with imaging accessible from 2006-2020. Pre-operative MRI scans were reviewed for 52 patients along with their most recent processing speed and/or working memory test scores. 274 radiological variables analysing tumour features and damage to brain structures were reported per patient using a standardised reporting tool. Univariate analysis was performed using Linear Regression with time-to-test analysed as a covariate. Multivariate analysis used Elastic Net Regression. RESULTS Univariate analysis revealed risk factors for slower processing speed included midline shift, tumour in the corpus callosum, right temporal periventricular white matter oedema, diffusion changes in the left frontal lobe or amygdala and FLAIR changes in the left caudate nucleus (p&amp;lt;0.005). Risk factors for impaired working memory included midline shift, cortical tumour location, left periventricular white matter oedema and diffusion or FLAIR changes in the left frontal lobe (p&amp;lt;0.005). Despite the limited population size and review of only pre-operative features, multivariate analysis produced multiple predictive models able to outperform chance when predicting processing speed and working memory outcomes. CONCLUSIONS This study provides evidence that a radiological language modelling approach can be utilised for outcome prediction. It identified imaging features predictive of cognitive impairments prior to surgery and radiotherapy. Further work is needed to assess inter-observer variability and validate these findings.

IMG-02. USING MRI RADIOMICS AND MACHINE LEARNING TO PREDICT OVERALL SURVIVAL FOR PEDIATRIC DIFFUSE MIDLINE GLIOMAS

Abstract BACKGROUND Pediatric diffuse midline gliomas (DMG) are aggressive central nervous system tumors with a median overall survival (OS) of less than one year from diagnosis. There is no curative therapy for DMG, and radiation therapy (RT) is the standard treatment. Magnetic resonance imaging (MRI) is the common noninvasive tool for DMG diagnosis and monitoring of tumor response to therapy. We developed an automatic pipeline to segment subregions of DMG and select MRI features that predict patient OS. METHODS We acquired diagnostic and post-RT multisequence MRI (T1, T1ce, T2, T2 FLAIR) and manual segmentations of pediatric DMG patients from two centers: 53 from Children’s National Hospital (internal) and 16 from Children’s Hospital of Philadelphia (external). We pretrained a deep learning model on a public adult brain tumor dataset, and finetuned the model to segment tumor core (TC) and whole tumor (WT) of DMG. We used PyRadiomics and sequential feature selection to select discriminative features based on the segmented volumes. Two machine learning models were trained on our internal cohort to predict patient 1-year survival from diagnosis. One model used only diagnostic tumor features and the other used both diagnostic and post-RT features. RESULTS For segmentation, Dice score (mean [median]±SD) was 0.91 (0.94)±0.12 and 0.74 (0.83)±0.32 for TC, and 0.88 (0.91)±0.07 and 0.86 (0.89)±0.06 for WT for internal and external cohorts, respectively. For OS prediction, accuracy was 77% and 81% at time of diagnosis, and 85% and 78% post-RT for internal and external cohorts, respectively. Heterogeneous WT intensity in baseline T2 FLAIR and smaller post-RT TC/WT volume ratio indicate longer OS. CONCLUSIONS Our method accurately predict OS for DMG patients and can be extended to other rare pediatric brain tumors. With automated and standardized analysis, early prognostication of OS can guide patient risk stratification and clinical decisions.

Associations between Radiomics and Genomics in Non-Small Cell Lung Cancer Utilizing Computed Tomography and Next-Generation Sequencing: An Exploratory Study

Background: Radiomics, an evolving paradigm in medical imaging, involves the quantitative analysis of tumor features and demonstrates promise in predicting treatment responses and outcomes. This study aims to investigate the predictive capacity of radiomics for genetic alterations in non-small cell lung cancer (NSCLC). Methods: This exploratory, observational study integrated radiomic perspectives using computed tomography (CT) and genomic perspectives through next-generation sequencing (NGS) applied to liquid biopsies. Associations between radiomic features and genetic mutations were established using the Area Under the Receiver Operating Characteristic curve (AUC-ROC). Machine learning techniques, including Support Vector Machine (SVM) classification, aim to predict genetic mutations based on radiomic features. The prognostic impact of selected gene variants was assessed using Kaplan–Meier curves and Log-rank tests. Results: Sixty-six patients underwent screening, with fifty-seven being comprehensively characterized radiomically and genomically. Predominantly males (68.4%), adenocarcinoma was the prevalent histological type (73.7%). Disease staging is distributed across I/II (38.6%), III (31.6%), and IV (29.8%). Significant correlations were identified with mutations of ROS1 p.Thr145Pro (shape_Sphericity), ROS1 p.Arg167Gln (glszm_ZoneEntropy, firstorder_TotalEnergy), ROS1 p.Asp2213Asn (glszm_GrayLevelVariance, firstorder_RootMeanSquared), and ALK p.Asp1529Glu (glcm_Imc1). Patients with the ROS1 p.Thr145Pro variant demonstrated markedly shorter median survival compared to the wild-type group (9.7 months vs. not reached, p = 0.0143; HR: 5.35; 95% CI: 1.39–20.48). Conclusions: The exploration of the intersection between radiomics and cancer genetics in NSCLC is not only feasible but also holds the potential to improve genetic predictions and enhance prognostic accuracy.

Travel distance does not affect overall survival in patients with appendiceal adenocarcinoma undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

IntroductionCytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is a potentially curative approach for appendiceal cancer (AC) with peritoneal dissemination and is most often employed at tertiary referral centers. Regionalization may provide geographic barriers to care for vulnerable patients. The aim of this study was to examine the effect of travel distance on oncologic outcomes of patients with AC treated with CRS-HIPEC. MethodsThe National Cancer Database (NCDB) was reviewed from 2006 through 2020 for patients with AC who underwent CRS-HIPEC. The primary comparison variable was distance (<50 miles vs ≥ 50 miles from the CRS-HIPEC facility). Demographic and tumor characteristics were analyzed. Primary outcome was overall survival (OS). Secondary outcomes were 30-day and 90-day mortality, readmission, and length of stay (LOS). ResultsDuring the study period, 1703 patients met inclusion criteria, with 1000 patients travelling < 50 miles for CRS-HIPEC (59 %) and 703 travelling ≥ 50 miles (41 %). Patients who traveled ≥ 50 miles were more likely to be non-Hispanic White (p < 0.001), have annual income less than $74,062, be treated at an academic center and live in the South-Atlantic region of the United States. There was no significant difference in OS between groups (Figure 1). There were no significant differences in 30-day postoperative survival, 90-day survival, or 30-day readmission. Post-operative LOS was 8.0 versus 9.0 days (p < 0.001). ConclusionsTravel distance ≥ 50 miles was not significantly associated with decreased OS or increased postoperative mortality, suggesting that regionalization of care does not worsen oncologic outcomes for patients with AC undergoing CRS-HIPEC.