Post-Treatment Imaging Changes in Primary Brain Tumors

Abstract

Discerning between primary brain tumor progression and treatment-related effect is a significant issue and a major challenge in neuro-oncology. The difficulty in differentiating tumor progression from treatment-related effects has important implications for treatment decisions and prognosis, as well as for clinical trial design and results. Conventional MRI is widely used to assess disease status, but cannot reliably distinguish between tumor progression and treatment-related effects. Several advanced imaging techniques are promising, but have yet to be prospectively validated for this use. This review explores two treatment-related effects, pseudoprogression and radiation necrosis, as well as the concept of pseudoresponse, and highlights several advanced imaging modalities and the evidence supporting their use in differentiating tumor progression from treatment-related effect.

Visual field changes as an early indicator of glioblastoma multiforme progression: two cases of functional vision changes before MRI detection

“…Following chemoradiotherapy, the irregular enhancement and growth patterns of GBM make it difficult to differentiate early tumor progression from pseudoprogression or radiation necrosis on neuroimaging 2,3,8. The updated RANO criteria address this dilemma with more stringent imaging criteria on conventional MRI for tumor response 4.…”

Glioblastoma multiforme: emerging treatments and stratification markers beyond new drugs

“…pseudoprogression, pseudoresponse and radiation necrosis. [55][56][57] The concept of radiogenomics takes quantitative imaging features and their impact on the clinical outcome into consideration while underlying aetiological and tumour-biological mechanisms are considered in the second step. With an increasing number of evolving imaging modalities from research towards clinical practice, there is growing need to carefully assess their practical use and to compare the additional benefit relative to the standard imaging, in an effort to complement and not to replace.…”

Update on Brain Tumors: New Developments in Neuro‐oncologic Diagnosis and Treatment, and Impact on Rehabilitation Strategies

“…Pseudo‐progression can also occur in the subacute period after RT, with MRI features similar to those of tumor progression. Pseudo‐progression may or may not present in conjunction with symptoms; diagnosis is typically made retrospectively after subsequent images show improvement without intervention [57].…”

“…Late‐delayed complications occur more than 6 months after RT, and are frequently irreversible. Radiation necrosis may occur, with localized tissue reaction including necrosis and edema [49,57]. Risk factors include total irradiation exceeding doses of 55‐60 Gy, diabetes, older age, and concurrent RT and chemotherapy [57].…”

“…Radiation necrosis may occur, with localized tissue reaction including necrosis and edema [49,57]. Risk factors include total irradiation exceeding doses of 55‐60 Gy, diabetes, older age, and concurrent RT and chemotherapy [57]. Clinical features of radiation necrosis are variable; although some patients are asymptomatic, others may have seizures or focal neurologic deficits.…”