Pritzl, Stephanie

Abstract Introduction: The landscape of classical hematology has undergone substantial evolution over the last decade, marked by new diagnostic tools, nuanced therapeutic strategies, and an expanding understanding of underlying pathophysiology. This increasing complexity often presents unique diagnostic and therapeutic challenges. These challenges are further compounded by workforce shortages in classical hematology marked by educational gaps, geographic limitations, and difficulty accessing prompt specialty care. Unlike the well-established “Tumor Boards” in oncology, a comparable dedicated, widely accessible forum for classical hematology has largely been absent. This gap contributes to potential practice heterogeneity and isolation, especially across dissimilar care settings and geographic regions, impacting the consistent application of evidence-based practices and access to specialized expertise. To address this critical need, the “Blood Board” initiative was created to serve as an informal, virtual resource for discussing classical hematology topics and cases, fostering diverse perspectives, and collaborative problem-solving. Methods: The Blood Board was formally launched in April 2025, operating as a bi-monthly, hour-long virtual meeting conducted via non-recorded videoconferencing. The forum was designed with broad inclusivity in mind, welcoming all healthcare professionals involved in the care of adult patients with classical hematologic disorders, including trainees such as hematology/oncology fellows, academic and community-based hematologists, and any other interested providers. To date, dissemination of this initiative has been by word of mouth and e-mails containing a calendar invitation have been sent to anyone interested in participating (https://forms.gle/doyHNSx1SVFBJZmy8). To facilitate participation from various practice models and geographical locations, the virtual format was prioritized, eliminating barriers of travel and time commitment often associated with traditional in-person conferences. Participation is voluntary, encouraging an open and informal environment for de-identified case presentations, didactic discussions, and expert opinion sharing. Self-reported data on participant demographics (e.g., role, practice setting) and geographical representation have been collected to assess the initiative's reach and impact. Results: To date, sessions have consistently garnered engagement with a median of five participants in attendance at each session. There have been over 20 unique participants representing a broad spectrum of roles including both trainees and practicing hematologists/hematologist-oncologists and drawing from private practice, community-based hospitals, and academic medical centers. Over half of all participants were either in fellowship or within five years of completion of training. The virtual format has successfully overcome geographical limitations, attracting attendees from numerous states including Alabama, Florida, Georgia, Maryland, Minnesota, Missouri, Pennsylvania, South Dakota, and Wisconsin highlighting its broad appeal and potential for knowledge dissemination across a wide professional network. Conclusions: The Blood Board has demonstrated utility and met a previously unaddressed need. Sustained intellectual interest in Blood Board, coupled with a wide geographical and professional reach underscores a critical role for accessible, free, and multidisciplinary collaborative platforms in the evolving field of classical hematology. Similar to Tumor Boards, Blood Board promotes knowledge exchange and evidence-based care, garners expert support for challenging cases, and harmonizes clinical approaches, which we hope may ultimately improve patient care outcomes across diverse settings. Furthermore, this platform facilitates a national classical hematology community to support workforce development. Future goals include expanding dissemination efforts, measuring specific educational benefits, analyzing impacts on patient care, and increasing participant diversity, including recruitment of advanced practice providers and pharmacists.

3020 Background: Radioligand therapy (RLT) use has been increasing with the approval of 177Lu-Dotatate for metastatic neuroendocrine tumors (NET) & 177Lu-PSMA-617 for metastatic castration resistant prostate cancer (mCRPC). Therapy-related myeloid neoplasms [tMN, including myelodysplastic syndrome (MDS) & acute myeloid leukemia, (AML)] have been reported after 177Lutetium (177Lu) for NET with rates of 2-20% & median time from first 177Lu to tMN of 2.8yrs [4-12]. Clonal hematopoiesis (CH) is a risk factor for tMN, with the spectrum of CH depending on selection pressures. To describe the prevalence of therapy selected CH & tMN, we performed a retrospective analysis of patients (pts) who had a bone marrow biopsy (BMB) post-177Lu. Methods: After IRB approval, we queried the electronic health record for pts with BMB post-177Lu. Pt demographics, treatment history, labs & BMB results were collected. Results: Fifty-seven pts met criteria, 41 (72%) with NET & 16 (28%) with mCRPC. . Median age at BMB was 68yrs (range, 28-85). Of the 57pts, prior treatments included: radiation (RT) in 21 (37%), temozolomide in 14 (25%), taxane in 15 (26%), & platinum agents in 10 (18%). The median number of 177Lu cycles was 4 (range, 1-11).Cytogenetics were available in 84% (n = 48) & were normal in 60% (n = 29). Of those with abnormal cytogenetics (n = 18, 38%), the most common abnormalities involved chromosome (chr) 7 (n = 12, 26%), chr 5 (n = 7, 15%), chr 20 (n = 5, 11%) and complex karyotypes in 7 (15%), with 3 (17%) of these patients having no mutations. Diagnoses were assessable in 49 (86%) pts: 15 (31%) with undefined cytopeniasand 16 (33%) with tMDS. Metastatic carcinoma was identified in 17 Fifty-one percent (n = 29), at a median of 0.5yrs (range, 0.04-2.6) after hematologic diagnosis. Conclusions: The enrichment of CH involving the DDR pathway in recipients of 177Lu underscores the impact of RLT on bone marrow progenitors.