Stereotactic Radiosurgery for Brain Metastases in Small Cell Lung Cancer: The Davidoff Cancer Center Experience.

BACKGROUND: Prophylactic cranial irradiation (PCI) exclusion in favor of brain magnetic resonance imaging (MRI) staging and surveillance in the management of small cell lung cancer (SCLC) is controversial yet accepted by some centers. The use of MRI suggests performing stereotactic radiosurgery (SRS) treatment for limited brain metastases. Data regarding SRS efficacy in this setting is limited. OBJECTIVES: To assess intracranial objective response rate (iORR), progression-free survival (iPFS), intracranial failure patterns, overall survival (OS) and time-to-whole-brain radiation therapy (WBRT)/death, whichever occurred first (TTWD) with SRS in SCLC. METHODS: The study comprised 10 consecutive SCLC patients with brain metastases treated with SRS and followed-up at Davidoff Cancer center between Aug 2012 and March 2019. Brain MRI images were reviewed by a neuro-radiology specialist. RESULTS: iORR was 57% as assessed by response assessment in neuro-oncology brain metastases. Intracranial progression developed in 8 patients. Median iPFS was 4.0 months (95% confidence interval [95%CI] 1.7-7.2). In-site, off-site and combined pattern of intracranial failure was seen in 0, 5, and 3 patients, respectively; median number of new brain lesions following SRS was 4 (range, 1-12). SRS was performed 10 additional times in 6 patients (median number of lesions irradiated per round was 1, range 1-5). WBRT was administered in 3 patients. Median TTWD was 20.9 months (95% CI, 1.9-26.8). Median OS since SRS administration was 23.2 months (95% CI, 4.2-not reached). CONCLUSIONS: MRI surveillance with multiple rounds of SRS may serve a reasonable alternative to PCI or therapeutic WBRT in SCLC.

Aberrant paramagnetic signals outside the tumor volume on routine surveillance MRI of brain tumor patients.

Late complications of cerebral radiation therapy (RT) involve vascular injury with acquired cavernous malformation, telangiectasias and damage to vascular walls which are well recognized in children. Its incidence in adults is unknown. Blood products and iron deposition that accompany vascular injury create paramagnetic effects on MRI. This study retrospectively investigated the frequency of paramagnetic lesions on routine surveillance MRI of adult brain tumor patients. MRI studies of 115 brain tumor patients were reviewed. Only studies containing sequences of either susceptibility weighted images or gradient echo or blood oxygenation level dependent imaging were included. Lesions inside the tumor volume were not considered. 68 studies fulfilled the above criteria and included 48 patients with previous RT (35 followed for >2 years and 13 for 1 year) and 20 patients who were not treated with RT. The median age at time of irradiation was 47 years. Aberrant paramagnetic lesions were found in 23/35 (65%) patients followed for >2 years after RT and in only 1/13 (8%) patients followed for 1-year after radiation (p = 0.03). The 1-year follow-up group did not differ from the control group [2/20 (9%)]. Most lesions were within the radiation field and none of the patients had related symptomatology. The number and incidence of these lesions increased with time and amounted to 75% over 3 years post RT. MRI paramagnetic signal aberrations are common findings in adult brain tumor patients that evolve over time after RT. The clinical significance of these lesions needs further investigation.

Myelin oligodendrocyte glycoprotein-positive optic neuritis masquerading as pseudotumor cerebri at presentation.

Optic neuritis (ON) is a common clinical manifestation in myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease. Other clinical manifestations include acute demyelinating encephalomyelitis, transverse myelitis and neuromyelitis optica spectrum disorders. Uncommon presentations of MOG-positive disease have recently been reported. ON in MOG-positive disease commonly involves the anterior portion of both optic nerves, leading to bilateral disc swelling. During the early stages of ON, in the setting of bilateral disc swelling and pain, patients may initially be suspected as pseudotumor cerebri (PTC). In this study, we report five cases presenting early in the course of MOG-IgG-related ON, which were misdiagnosed as PTC in the emergency department. MOG-IgG-positive ON requires timely treatment to prevent RNFL and vision loss secondary to the high relapse rate associated with these antibodies. Our aim is to increase the awareness of the unique findings of MOG-IgG-positive ON, which may initially mimic PTC, thereby delaying treatment.