How Imaging Advances Are Defining the Future of Precision Radiation Therapy.

Radiation therapy is fundamental in the treatment of cancer. Imaging has always played a central role in radiation oncology. Integrating imaging technology into irradiation devices has increased the precision and accuracy of dose delivery and decreased the toxic effects of the treatment. Although CT has become the standard imaging modality in radiation therapy, the development of recently introduced next-generation imaging techniques has improved diagnostic and therapeutic decision making in radiation oncology. Functional and molecular imaging techniques, as well as other advanced imaging modalities such as SPECT, yield information about the anatomic and biologic characteristics of tumors for the radiation therapy workflow. In clinical practice, they can be useful for characterizing tumor phenotypes, delineating volumes, planning treatment, determining patients' prognoses, predicting toxic effects, assessing responses to therapy, and detecting tumor relapse. Next-generation imaging can enable personalization of radiation therapy based on a greater understanding of tumor biologic factors. It can be used to map tumor characteristics, such as metabolic pathways, vascularity, cellular proliferation, and hypoxia, that are known to define tumor phenotype. It can also be used to consider tumor heterogeneity by highlighting areas at risk for radiation resistance for focused biologic dose escalation, which can impact the radiation planning process and patient outcomes. The authors review the possible contributions of next-generation imaging to the treatment of patients undergoing radiation therapy. In addition, the possible roles of radio(geno)mics in radiation therapy, the limitations of these techniques, and hurdles in introducing them into clinical practice are discussed. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

What to Expect (and What Not) from Dual-Energy CT Imaging Now and in the Future?

Dual-energy CT (DECT) imaging has broadened the potential of CT imaging by offering multiple postprocessing datasets with a single acquisition at more than one energy level. DECT shows profound capabilities to improve diagnosis based on its superior material differentiation and its quantitative value. However, the potential of dual-energy imaging remains relatively untapped, possibly due to its intricate workflow and the intrinsic technical limitations of DECT. Knowing the clinical advantages of dual-energy imaging and recognizing its limitations and pitfalls is necessary for an appropriate clinical use. The aims of this paper are to review the physical and technical bases of DECT acquisition and analysis, to discuss the advantages and limitations of DECT in different clinical scenarios, to review the technical constraints in material labeling and quantification, and to evaluate the cutting-edge applications of DECT imaging, including artificial intelligence, qualitative and quantitative imaging biomarkers, and DECT-derived radiomics and radiogenomics.

Cortical blindness secondary to posterior reversible encephalopathy syndrome, recovered by successful blood pressure management / Cegueira cortical secundária à síndrome de encefalopatia reversível posterior recuperada pelo controle bem sucedido da pressão arterial

ABSTRACT We report a case of cortical blindness secondary to posterior leukoencephalopathy syndrome, which was successfully treated by blood pressure management. A 66-year-old white man presented at the emergency room complaining of severe frontal headache, disorientation, and progressive blurred vision. The initial physical examination disclosed a blood pressure of 200/176 mmHg. One hour later the patient exhibited mental confusion and bilateral blindness. Computed tomography and magnetic resonance imaging were performed, and a systemic workup was conducted, resulting in a diagnosis of posterior leukoencephalopathy syndrome. This syndrome is a rare manifestation of systemic hypertension that requires proper diagnosis and management to avoid irreversible brain damage. Early recognition of this condition and prompt control of the patient's blood pressure are essential because they may bring about a reversal of the syndrome, which may otherwise result in permanent brain damage.

RESUMO Relatamos um caso de cegueira cortical secundário à síndrome de leucoencefalopatia posterior recuperado pelo controle bem sucedido da pressão arterial. Um homem branco de 66 anos de idade compareceu à emergência com queixa de dor de cabeça frontal severa, desorientação e embaçamento progressivo da visão. O exame físico inicial revelou uma pressão arterial de 200/176 mmHg. Uma hora depois, o paciente apresentou confusão mental e cegueira bilateral. Após a tomografia e a ressonância nuclear magnética, o tratamento sistêmico foram realizados e o diagnóstico de síndrome da leucoencefalopatia posterior foi realizado. A síndrome de leucoencefalopatia posterior é uma manifestação rara de hipertensão sistêmica que requer um diagnóstico e gerenciamento adequados para evitar danos cerebrais irreversíveis. O reconhecimento precoce desta condição e o controle imediato da pressão arterial são essenciais porque podem levar à reversão da síndrome, o que, de outra forma, pode resultar em dano cerebral permanente.