Imaging after GliaSite brachytherapy: prognostic MRI indicators of disease control and recurrence.
ABSTRACT In this study, we analyzed the magnetic resonance imaging (MRI) changes in patients after GliaSite treatment and characterized the prognostic MRI indicators in these patients.
A total of 25 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System. Patients at the Johns Hopkins Hospital with recurrent glioblastoma multiforme underwent surgical resection followed by GliaSite balloon implantation. Available MRI scans for 20 patients were obtained throughout the post-GliaSite treatment course. These were reviewed and analyzed for prognostic significance.
After GliaSite treatment, all patients developed some degree of T(1)-weighted contrast and T(2)-weighted hyperintensity around the resection cavity. The development of enhancement on T(1)-weighted contrast-enhanced imaging and the size of these lesions, in the absence of increasing T(2)-weighted hyperintensity, before clinical progression was not associated with decreased survival. Patients with T(1)-weighted enhancement >1 cm had a median survival of 13.6 months and those with T(1)-weighted lesions <or=1 cm had a median survival of 8.5 months (p = .014). In contrast, the development of larger areas of T(2)-weighted hyperintensity surrounding the resection cavity was significantly associated with poorer survival (p = .027).
After GliaSite treatment, characteristic T(1)- and T(2)-weighted changes are seen on MRI. Greater T(1)-weighted changes in the absence of increasing edema appears not to indicate disease progression; however, greater T(2)-weighted changes were associated with decreased survival. These findings suggest that T(1)-weighted enhancement in the absence of concomitant edema after GliaSite treatment might represent pseudoprogression. Conversely, increasing T(2)-weighted hyperintensity might reflect infiltrative disease progression. These results provide a framework for the analysis of disease control in future prospective studies of GliaSite treatment.
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ABSTRACT: Which imaging techniques most accurately differentiate true tumor progression from pseudo-progression or treatment related changes in patients with previously diagnosed glioblastoma? These recommendations apply to adults with previously diagnosed glioblastoma who are suspected of experiencing progression of the neoplastic process. Magnetic resonance imaging with and without gadolinium enhancement is recommended as the imaging surveillance method to detect the progression of previously diagnosed glioblastoma. Magnetic resonance spectroscopy is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma. The routine use of positron emission tomography to identify progression of glioblastoma is not recommended. Single-photon emission computed tomography imaging is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma.Journal of Neuro-Oncology 04/2014; DOI:10.1007/s11060-013-1330-0 · 2.79 Impact Factor
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ABSTRACT: A familiar challenge for neuroradiologists and neuro-oncologists is differentiating between radiation treatment effect and disease progression in the CNS. Both entities are characterized by an increase in contrast enhancement on MRI and present with similar clinical signs and symptoms that may occur either in close temporal proximity to the treatment or later in the disease course. When radiation-related imaging changes or clinical deterioration are mistaken for disease progression, patients may be subject to unnecessary surgery and/or a change from otherwise effective therapy. Similarly, when disease progression is mistaken for treatment effect, a potentially ineffective therapy may be continued in the face of progressive disease. Here we describe the three types of radiation injury to the brain based on the time to development of signs and symptoms - acute, subacute and late - and then review specific imaging changes after intensity-modulated radiation therapy, stereotactic radiosurgery and brachytherapy. We provide an overview of these phenomena in the treatment of a wide range of malignant and benign CNS illnesses. Finally, we review the published data regarding imaging techniques under investigation to address this well-known problem.Future Oncology 05/2014; 10(7):1277-97. DOI:10.2217/fon.13.271 · 2.61 Impact Factor