Monitoring of Current Cancer Therapy by Positron Emission Tomography and Possible Role of Radiomics Assessment

Abstract

Evaluation of cancer therapy with imaging is crucial as a surrogate marker of effectiveness and survival. The unique response patterns to therapy with immune-checkpoint inhibitors have facilitated the revision of response evaluation criteria using FDG-PET, because the immune response recalls reactive cells such as activated T-cells and macrophages, which show increased glucose metabolism and apparent progression on morphological imaging. Cellular metabolism and function are critical determinants of the viability of active cells in the tumor microenvironment, which would be novel targets of therapies, such as tumor immunity, metabolism, and genetic mutation. Considering tumor heterogeneity and variation in therapy response specific to the mechanisms of therapy, appropriate response evaluation is required. Radiomics approaches, which combine objective image features with a machine learning algorithm as well as pathologic and genetic data, have remarkably progressed over the past decade, and PET radiomics has increased quality and reliability based on the prosperous publications and standardization initiatives. PET and multimodal imaging will play a definitive role in personalized therapeutic strategies by the precise monitoring in future cancer therapy.

Assessment of Response to Immunotherapy in Patients with Hodgkin Lymphoma: Towards Quantifying Changes in Tumor Burden Using FDG-PET/CT

“…Recently, considering tumor heterogeneity and differences in therapy response, artificial intelligence (AI) approaches, radiomics and machine learning algorithms, have emerged as non-invasive technologies using medical imaging analyses. AI can extract significant quantitative data from patients' medical images and correlate image features with diagnostic and therapeutic outcomes [52,53]. Radiomics has been applied in lymphomas to examine baseline FDG-PET for differential diagnosis from other malignancies and in evaluations of bone marrow involvement and pre-treatment risk [54,55], but, currently, no data are available for radiomic analyses in the context of assessments of the response to immunotherapy in lymphomas [56,57].…”

PET/CT in treatment response assessment in lung cancer. When should it be recommended?

“…Another key role of FDG-PET/CT is in relation to post-treatment evaluation of patients undergoing conventional chemotherapy and targeted treatments. Assessing early features of favorable response to treatment is of immense value in reducing time, costs and toxicity from delivering unproductive therapies [22].…”

Enhancing MRI through high loading of superparamagnetic nanogels with high sensitivity to the tumor environment

“…Currently, clinical tumor diagnosis primarily relies on imaging techniques such as computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). [4][5][6] While PET and SPECT offer high sensitivity and penetration depth, they can be costly and raise concerns about radiation exposure for patients. In contrast, MRI diagnosis is more widely utilized in clinical settings due to its noninvasiveness, safety, high spatial resolution, and absence of tissue penetration limitations.…”