Abstract

Tumor heterogeneity, defined as the biological variability within a single tumor or across different lesions in a patient, is a critical challenge in oncology due to its influence on prognosis and treatment response. This variability encompasses genetic, epigenetic, and phenotypic differences, enabling tumors to adapt and resist conventional therapeutic interventions. Understanding this internal variability is fundamental to designing effective treatment strategies, and advanced imaging studies, such as positron emission tomography combined with computed tomography (PET/CT), provide an indispensable tool to map these differences and guide treatment planning. In the assessment of PET/CT images, quantitative parameters such as Metabolic Tumor Volume (MTV), Total Lesion Glycolysis (TLG), and Standardized Uptake Value (SUV) play a key role in interpreting tumor heterogeneity. These parameters not only allow for a precise quantification of tumor burden but also aid in identifying subpopulations of cells within the tumor with varying levels of aggressiveness or resistance to treatment. These parameters are essential for imaging specialists to understand the tumor’s complexity and to develop a more accurate clinical interpretation tailored to each patient’s unique tumor biology. The integration of MTV, TLG, and SUV in PET/CT clinical evaluations facilitates the adaptation of treatments to the tumor’s metabolic profile, optimizing therapeutic effectiveness and enabling the identification of tumors with a high potential for resistance and progression.

Keywords

cancer heterogeneity, genetics, epigenetics, mutations