Brain imaging and behavior
-
Brain Imaging Behav · Dec 2013
ReviewDiffusion tensor MRI of chemotherapy-induced cognitive impairment in non-CNS cancer patients: a review.
Patients with non-central nervous system cancers often experience subtle cognitive deficits after treatment with cytotoxic agents. Therapy-induced structural changes to the brain could be one of the possible causes underlying these reported cognitive deficits. In this review, we evaluate the use of diffusion tensor imaging (DTI) for assessing possible therapy-induced changes in the microstructure of the cerebral white matter (WM) and provide a critical overview of the published DTI research on therapy-induced cognitive impairment. ⋯ In this paper, we will also introduce the basics of diffusion tensor imaging and how it can be applied to evaluate effects of therapy on structural changes in cerebral WM. The review concludes with considerations and discussion regarding DTI data interpretation and possible future directions for investigating therapy-induced WM changes in cancer patients. This review article is part of a Special Issue entitled: Neuroimaging Studies of Cancer and Cancer Treatment.
-
Brain Imaging Behav · Dec 2013
Review Comparative StudyIntegrating imaging findings in evaluating the post-chemotherapy brain.
Cognitive complaints following cancer and cancer therapy are common. Many studies have investigated the effects of chemotherapy on the brain. However, the mechanisms for the associated cognitive impairment are not well understood. ⋯ This review examines recent neuroimaging studies on cancer- and chemotherapy-related cognitive dysfunction in non-central nervous system cancers and compares findings across imaging modalities. Grey matter volume reductions and decreases in white matter integrity are seen after exposure to adjuvant chemotherapy for breast cancer, and functional studies have illuminated both hypo- and hyperactivations in many of the same regions months to years following therapy. These comparisons can assist in further characterizing the dysfunction reported by patients and contribute to a better understanding of the mechanisms involved.
-
With increasing survival, cognitive problems after systemic treatment for non-CNS cancers are a growing concern. Functional magnetic resonance imaging (fMRI) is a noninvasive neuroimaging technique that has the potential to uncover the neural circuitry underlying cognitive problems after systemic treatment in cancer patients. Here, we provide an in depth review of the 14 fMRI studies that have been published to date on potential neurotoxic side effects of systemic treatment for non-CNS cancers. ⋯ Two small studies in prostate cancer patients, finally, provide preliminary evidence for reduced activation in task-relevant brain regions after androgen deprivation therapy, suggestive of reduction of neural function. Statistical correction for multiple comparisons in the reviewed studies is typically quite lenient. We suggest that future studies should preferably include larger sample sizes to allow proper statistical correction for multiple comparisons and include comprehensive neurocognitive tests and multimodal MRI to facilitate the interpretation of the observed fMRI findings.
-
Brain Imaging Behav · Dec 2013
Neuroimaging biomarkers and cognitive function in non-CNS cancer and its treatment: current status and recommendations for future research.
Cognitive changes in patients undergoing treatment for non-central nervous system (CNS) cancers have been recognized for several decades, yet the underlying mechanisms are not well understood. Structural, functional and molecular neuroimaging has the potential to help clarify the neural bases of these cognitive abnormalities. Structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging (DTI), MR spectroscopy (MRS), and positron emission tomography (PET) have all been employed in the study of cognitive effects of cancer treatment, with most studies focusing on breast cancer and changes thought to be induced by chemotherapy. ⋯ A systems biology framework incorporating multimodality neuroimaging, genetics and other biomarkers will be highly informative regarding individual differences in risk and protective factors and disease- and treatment-related mechanisms. Studies of interventions targeting cognitive changes are also needed. These next steps are expected to identify novel protective strategies and facilitate a more personalized medicine for cancer patients.