Citations

Abstract Meniscal extrusion (ME) is a valuable, noninvasive diagnostic tool for meniscus pathology. In addition, ultrasound can allow for instant results in the office. However, ME is a fragile metric in the degree of millimeters. The inconsistent techniques used by different authors in the literature and the additional operator variability that ultrasound technology introduces make it important a systematic approach is used. The purpose of this study is to propose a reproducible technique. The current authors recommend having the patient in (1) 30° of knee flexion while weight‐bearing, (2) capturing the image at the posterior border of the medial collateral ligament, (3) using a reference line parallel to the articular margin of the tibia, and (4) measuring ME at the coronal midpoint of the outermost edge of the meniscus. Technique Video video See video under supplementary data.

SummaryThis phase II study evaluated time‐limited (24 cycles) treatment with ibrutinib and ixazomib in newly diagnosed (NDWM; n = 9) and relapsed/refractory (RRWM; n = 12) Waldenström macroglobulinaemia (WM). The overall response rate (ORR) was 76.2% (n = 16) in 21 evaluable patients with no patient achieving a complete response (CR). The median duration of treatment was 15.6 months, and after a median follow‐up time of 25.7 months, the median progression‐free survival (PFS) was 22.9 months. While the primary end‐point was not met (CR rate at any time) and 28.5% discontinued treatment due to toxicity, ibrutinib plus ixazomib led to a clinically meaningful ORR and PFS. Combined Bruton's tyrosine kinase (BTK) and proteasome inhibition merits further evaluation in WM.

Abstract Photogrammetry scans has directed attention to the development of advanced camera systems to improve the creation of three-dimensional (3D) models, especially for educational and medical-related purposes. This could be a potential cost-effective method for neuroanatomy education, especially when access to laboratory-based learning is limited. The aim of this study was to describe a new photogrammetry system based on a 5 Digital Single-Lens Reflex (DSLR) cameras setup to optimize accuracy of neuroanatomical 3D models. One formalin-fixed brain and specimen and one dry skull were used for dissections and scanning using the photogrammetry technique. After each dissection, the specimens were placed inside a new MedCreator® scanner (MedReality, Thyng, Chicago, IL) to be scanned with the final 3D model being displayed on SketchFab® (Epic, Cary, NC) and MedReality® platforms. The scanner consisted of 5 cameras arranged vertically facing the specimen, which was positioned on a platform in the center of the scanner. The new multi-camera system contains automated software packages, which allowed for quick rendering and creation of a high-quality 3D models. Following uploading the 3D models to the SketchFab® and MedReality® platforms for display, the models can be freely manipulated in various angles and magnifications in any devices free of charge for users. Therefore, photogrammetry scans with this new multi-camera system have the potential to enhance the accuracy and resolution of the 3D models, along with shortening creation time of the models. This system can serve as an important tool to optimize neuroanatomy education and ultimately, improve patient outcomes.

Abstract White matter dissection (WMD) involves isolating bundles of myelinated axons in the brain and serves to gain insights into brain function and neural mechanisms underlying neurological disorders. While effective, cadaveric brain dissections pose certain challenges mainly due to availability of resources. Technological advancements, such as photogrammetry, have the potential to overcome these limitations by creating detailed three-dimensional (3D) models for immersive learning experiences in neuroanatomy. Objective: This study aimed to provide a detailed step-by-step WMD captured using two-dimensional (2D) images and 3D models (via photogrammetry) to serve as a comprehensive guide for studying white matter tracts of the brain. One formalin-fixed brain specimen was utilized to perform the WMD. The brain was divided in a sagittal plane and both cerebral hemispheres were stored in a freezer at -20°C for 10 days, then thawed under running water at room temperature. Micro-instruments under an operating microscope were used to perform a systematic lateral-to-medial and medial-to-lateral dissection, while 2D images were captured and 3D models were created through photogrammetry during each stage of the dissection. Dissection was performed with comprehensive examination of the location, main landmarks, connections, and functions of the white matter tracts of the brain. Furthermore, high-quality 3D models of the dissections were created and housed on SketchFab®, allowing for accessible and free of charge viewing for educational and research purposes. Our comprehensive dissection and 3D models have the potential to increase understanding of the intricate white matter anatomy and could provide an accessible platform for the teaching of neuroanatomy.

TPS714 Background: 1st-line induction platinum-based chemotherapy followed by switch maintenance Av is the current preferred standard of care in patients (pts) with aUC who do not progress after platinum-based chemotherapy. There is an significant need to further improve outcomes by combining Av with an effective, non-cross resistant therapy with non-overlapping toxicity. CABO is an oral inhibitor of MET, VEGFR and TAM family receptors involved in tumor growth, angiogenesis and immune cell regulation and has shown efficacy in UC in combination with PD-1/PD-1L1 inhibitor. We hypothesized that CABO-Av combination would improve survival vs Av alone and have an acceptable safety profile as switch maintenance therapy in mUC. Methods: MAIN-CAV is a phase III randomized, multicenter, international trial for pts with locally advanced/metastatic UC (including cN3M0 only)) who do not progress after 4-6 cycles of any platinum-based chemotherapy (gem-cis, gem-carbo, MVAC or ddMVAC). 654 adults are randomized 1:1 within 3-10 weeks (wk) after last dose of chemotherapy to receive Av 800 mg IV every 2 wk or Av and CABO 40 mg daily for up to 2 yrs. Key eligibility criteria include ECOG PS 0-1, no prior use of anti-PD(L)1, no CNS metastases, no major surgery within 4 wks, no uncontrolled hypertension or cardiovascular disorders. Pts are stratified based on 1) best response to 1L chemotherapy: complete vs partial response vs stable disease and 2) presence vs absence of visceral metastases. The primary endpoint is overall survival (OS) with assumptions of 1-sided alpha 0.025, power 80%, median OS 21 months (mo) with Av and hazard ratio 0.75, thus hypothesizing median OS 28 mo on CABO-Av. Key secondary endpoints include progression-free survival, safety, tolerability, and efficacy of CABO-Av vs Av alone based on RECIST 1.1 and iRECIST criteria (and PD-L1 status).Quality of life (QOL) are assessed using EQ-5D-5L, PROMIS-Fatigue 4a, EORTC QLQ-C30, EORTC QLQ-BLM30 between pts on CABO-Av vs Av alone. Biomarkers of response and resistance to Av will be assessed using baseline archival tissues, baseline and serial blood, ctDNA, stool and urine. Imaging studies will test the correlation of established and new radiomic signatures with survival, adverse events and QOL and incorporate both radiologic and biologic features to assess their potential association with outcomes. This trial would be the first to systematically address whether adding the multitargeted TKI, CABO, to Av improves survival vs Av alone as 1L maintenance therapy. https://acknowledgments.alliancefound.org . Support: U10CA180821, U10CA180882; U24CA196171, U10CA180863 (CCTG); Clinical trial information: NCT05092958 .

TPS354 Background: Carriers of germline pathogenic variants or mutations in BRCA2 and BRCA1 (referred to here as gBRCA1/2m) are enriched in metastatic prostate cancer (PrCa), and now have FDA-approved options for PARP inhibitors in late-stage disease. The NCCN guidelines recommends germline genetic testing for PrCa patients with metastatic, node positive and high risk localized prostate cancer. Prior studies have shown that gBRCA1/2m carriers with PrCa are more likely to have high-risk disease (6,7) and to develop lethal disease even after curative intent treatment (8,9). In other gBRCA1/2m-related cancers (breast, ovarian and pancreas), platinum-based regimens are part of neoadjuvant and front-line metastatic therapy options. Carboplatin is a well-tolerated, widely available and inexpensive DNA-damaging alkylating agent that is familiar to oncologists. The study hypothesis is that 4 cycles of neoadjuvant carboplatin, followed by radical prostatectomy for patients with localized high/very high risk PrCa and g BRCA1/2m will result in a meaningful pathologic complete response (pCR) rate. Methods: S2210 is a single-arm, open label study of 12 wks neoadjuvant carboplatin (4 cycles of AUC 5 every 21 days), followed by radical prostatectomy. Key eligibility criteria include people with high/very high-risk disease: cT3a or Grade Group 4-5 PrCa and/or PSA>20 ng/mL, have no evidence of distant metastases by conventional imaging (PSMA-PET-detected mets permitted if conventional imaging is negative and surgeon deems PSMA-detected sites resectable), who are candidates for radical prostatectomy and carboplatin, and have documented evidence of gBRCA1/2m through testing in a CLIA-certified lab. ADT prior to registration is permitted but must be discontinued on study. The study hypothesis is that the study treatment will result in ³30% rate of pathologic complete response (pCR, primary endpoint). A two-stage design will be used such that if ³1 of first 20 eligible patients achieves pCR, 20 further evaluable patients will be enrolled. This design has a significance level of 4.7%, and a power of 99%. Secondary endpoints include biochemical recurrence-free (at 2-, 3-, 5-yrs), metastasis-free and overall survival. Translational/correlative studies include analysis of 2nd allele inactivation in tumor, HRD signature, and ctDNA signature for monitoring of recurrence. S2210 was activated in August 2023. Clinical trial information: NCT05806515 .

TPS246 Background: Prostate cancer (PC) is common and despite recent advances in treatment options, patients with metastatic disease still have poor outcomes, warranting the development of new effective therapies in this setting. Prostate-specific membrane antigen (PSMA) is expressed in benign and malignant prostate tissues and luminal surface of salivary/lacrimal glands, small intestine and renal tubules. The double PSMA binding moiety of SAR-bisPSMA in 64Cu-SAR-bisPSMA (imaging) and 67Cu-SAR-bisPSMA (therapy) may offer advantages compared to currently used single-target PSMA agents. Clinical evidence demonstrated 2-3 times higher uptake of 64Cu-SAR-bisPSMA compared to the single-target PSMA agent, 68Ga-PSMA-11. Pre-clinical efficacy data of 67Cu-SAR-bisPSMA in mice showed statistically significant tumor growth inhibition compared to the control group as well as a dose-dependent delay in eventual tumor regression in a PC xenograft study. These results led to the development of this clinical study, which aims to assess safety and anti-tumor efficacy of 67Cu-SAR-bisPSMA in patients with metastatic castrate resistant PC (mCRPC). Methods: SECuRE is a phase I/IIa multi-center, open-label, non-randomized, dose-escalation and cohort expansion study of 64Cu-SAR-bisPSMA and 67Cu-SAR-bisPSMA. mCRPC patients with progression, prior exposure to at least one androgen receptor pathway inhibitor, and positive 64Cu-SAR-bisPSMA PET may be treated with 67Cu-SAR-bisPSMA. This study is being conducted in 3 phases: a 64Cu-SAR-bisPSMA Dosimetry Phase (n=6), a 67Cu-SAR-bisPSMA Dose Escalation Phase (n=up to 24), and a 67Cu-SAR-bisPSMA Cohort Expansion Phase (n=14). The primary and key secondary objectives include assessment of 64Cu- and 67Cu-SAR-bisPSMA safety and dosimetry, determining the maximum tolerated dose (MTD) or maximum feasible dose (MFD) and anti-tumor efficacy of 67Cu-SAR-bisPSMA. The 67Cu-SAR-bisPSMA dose levels investigated in the escalation phase include: 4 GBq (cohort 1, single dose), 8 GBq (cohort 2, single dose), 12 GBq (cohort 3, single dose) and up to 24 GBq across two doses (cohort 4, two doses at MTD or MFD). The Dose Expansion Phase of the study will allow the administration of up to 4 doses of 67Cu-SAR-bisPSMA at the MTD/MFD. Response measurements include reduction in PSA levels, radiological progression-free survival, duration of response and overall survival. Radiological response will be assessed by RECIST 1 V1.1 and PCWG3. At the time of submission of this abstract, cohort 3 is open for recruitment and no dose limiting toxicities have been observed to date. Clinical trial information: NCT04868604 .

98 Background: The risk of secondary primary malignancies (SPM) among the survivors of GU cancer is not well-established. In this study, we attempt to describe the patterns of SPMs in patients diagnosed with GU cancers. Methods: The Surveillance, Epidemiology, and End Results (SEER) database (SEER*Stat 8.4.2) was searched to obtain data on the incidence of SPM in adult patients (age >18 years) diagnosed with GU cancers, including prostate, renal, and bladder cancer. Standardized incidence ratios (SIRs) with a 95% confidence interval (CI) were calculated. SIR was defined as the observed SPMS from each category divided by the expected number of SPMs in the age-matched US population for the same period. The data was further stratified by age (<50y, 50-70y, >70y), race (White, Black, Asian/Pacific Islander), ethnicity (Hispanic, non-Hispanic), chemotherapy, and radiotherapy exposure. Results: A total of 1,041,217 patients were included in this analysis. In patients diagnosed with GU cancer, the incidence of overall SPM was 11%. Particularly, patients with GU cancers were observed to have a high incidence of Endocrine system SPM (1.52; 1.45-1.59), and urinary system SPM (1.51; 1.49-1.53) These results were consistent by different sociodemographic groups. In patients diagnosed with prostate cancer, the incidence of thyroid SPM was increased (1.31; 1.23-1.39). Particularly, prostate cancer patients treated with radiation therapy had increased incidence rates of SPM in the peritoneum, omentum and mesentery (1.57; 0.79-2.81) and urinary bladder (1.36;1.32-1.40) was higher as compared to those with no exposure to radiation therapy (1.11;1.08-1.13 and 1.03;1-1.06 respectively). Bladder cancer patients had an overall increased incidence of SPM in the esophagus (1.21; 1.08-1.35), lung, bronchus, trachea, and other respiratory organs (1.97;1.92-2.01), prostate (3.50;3.4-3.6) and kidney (1.86;1.76-1.97). A higher incidence of renal pelvis, ureter and other urinary organ SPM (11.08;10.48-11.07) was also notable in this population. Similarly, kidney cancer patients had a higher incidence of the endocrine system (3.00;2.74-3.27), prostate (1.24;1.2-1.29) and bladder 1.78;1.68-1.79 SPMs. Conclusions: This population-based study shows an increased risk of SPM development in GU cancer survivors compared to the general population. Clinicians should keep a high index of suspicion for SPMs and initiate appropriate workups at early warning signs.

93 Background: The treatment paradigm for mCSPC patients has rapidly evolved over the last few years with the emergence of triplet therapy and prognostication by volume of disease. However, the health economic implications of triplet therapy by disease volume remain unclear. Methods: A Markov model where patients transitioned between the progression-free, progression and death states was developed. State utilities were derived from the LATITUDE trial. Point probabilities for overall survival, progression-free survival, grade ≥ 3 and 5 toxicities were obtained from the eligible mCSPC phase III clinical trials. Medicare Advantage and commercial total paid amounts (2022 US$) of treatments were obtained from OptumLabs Data Warehouse. Costs and disutilities of adverse events were derived from published literature. Half-cycle corrected costs and utilities were accrued monthly over a 20-year lifetime horizon and were discounted at 3%. Monte Carlo simulation was used to calculate incremental cost-effectiveness ratios (ICERs). A willingness-to-pay (WTP) threshold of US$100,000 was used. Results: In terms of Medicare Advantage payer’s perspective (Table), docetaxel (D)+ADT was observed to provide additional 0.068 QALYs compared to ADT at an ICER of US$16,544 per QALY in high volume disease. Compared to D+ADT, abiraterone (AAP) triplet provided additional 1.03 QALYs at US$56,641 per QALY. Compared to AAP triplet, apalutamide (APA)+ADT provided additional 0.048 QALYs at US$5,846,248 per QALY in high volume disease. In low volume disease, D+ADT provided 0.45 more QALYs at US$20,690 per QALY compared to ADT alone. Compared to D+ADT, AAP triplet provided an additional 1.51 QALYS at US$44,267 per QALY. In terms of total paid commercial costs, AAP triplet provided an additional 1.19 QALYs compared to ADT at US$91,952 per QALY in high volume disease. In low volume, D+ADT provided additional 0.38 QALYs at US$22,058 per QALY compared to ADT. Compared to D+ADT, AAP triplet provided a 0.97 QALY gain at US$105,958 per QALY. Compared to AAP triplet, darolutamide (DARO) triplet provided a 0.47 QALY at US$689,196 per QALY. Compared to DARO triplet, APA+ADT provided an additional 0.49 QALYs at an ICER of US$971,389 per QALY. All other treatments (not reported here) were dominated. Conclusions: At the selected WTP of US$100,000 per QALY, AAP triplet therapy was most likely the cost-effective strategy in overall mCSPC population particularly in patients with high volume disease. However, these results should be interpreted with careful accounting for timing of metastases. [Table: see text]