en AI in Medicine پژوهشي Original Article <div style="text-align: justify;"><span style="font-family:Times New Roman;"><span style="line-height:2;"><span style="font-size:14px;"><strong>Background and Objective:</strong> &nbsp;Hematological malignancies are facing increasing complexity in diagnosis and treatment, which requires multidisciplinary decision-making in tumor boards. Traditional predictive AI models have limited clinical application due to limitations such as black-box nature and inability to reason in multiple steps. This study aimed to design a comprehensive conceptual framework for a multi-agent Agentic AI system architecture to support decision-making in hemato-oncology tumor boards.<br> <strong>Methods: </strong>This conceptual study was conducted using the Design Science Research methodological framework. The proposed architecture was developed based on the convergence of three reference frameworks, including the ReAct reasoning paradigm, the HL7 FHIR R4 standard, and the NIST AI RMF 1.1 framework. The system architecture was described using Unified Modeling Language (UML) 2.5, and four specialized agents (Data Parser, Genomics, Guideline RAG, and Orchestrator) were specified based on a standard seven-component design pattern. The architecture was evaluated using the multidimensional RAMSES framework by an eight-member multidisciplinary expert panel.<br> <strong>Results: </strong>The proposed architecture was designed with five distinct layers (data acquisition, agent coordination, knowledge and tools, safety and governance, and presentation). The system employed a multilayered Defense-in-Depth security approach with four independent protective layers, which reduced the hallucination rate from 18.4% to 3.2%. An application scenario based on an AML case showed that the system was able to process a complex clinical file in 3 minutes and 21 seconds and produce a 2,847-word structured report with a confidence score of 0.82. The RAMSES evaluation yielded an overall average score of 4.4 out of 5, across the three functional (4.7), technical (4.7), and clinical (4.3) dimensions.<br> <strong>Conclusion: &nbsp;</strong>This study provides a roadmap for the transition from predictive AI to agentic AI in hemato-oncology. The proposed multi-agent architecture, while preserving the human-in-the-loop principle, ensures reliability, explainability, and regulatory compliance, and can reduce the cognitive burden on tumor boards while democratizing access to precision medicine.</span></span></span></div> Artificial intelligence, Multi-agent system, Hemato-oncology, Tumor board , Clinical decision support , System architecture 107 120 http://ijbc.ir/browse.php?a_code=A-10-963-5&slc_lang=en&sid=1 Samira Babaei smrbabaei94@gmail.com No Department of Nursing, Naghadeh School of Nursing, Urmia University of Medical Sciences, Urmia, Iran. Mustafa Ghaderzadeh mustafa.ghaderzadeh@gmail.com Yes Boukan Faculty of Medical Sciences, Urmia University of Medical Sciences, Urmia, Iran. Cirruse Salehnasab cirruse.salehnasab@gmail.com No Social Determinants of Health Research Center, Yasuj University of Medical Sciences, Yasuj, Iran.