The Use of Treatment Response Assessment Maps in Discriminating Between Radiation Effect and Persistent Tumoral Lesion in Metastatic Brain Tumors Treated with Gamma Knife Radiosurgery.

BACKGROUND: Traditional imaging modalities are not useful in the follow-up of irradiated metastatic brain tumors, because radiation can change imaging characteristics. We aimed to assess the ability of treatment response assessment maps (TRAMs) calculated from delayed-contrast magnetic resonance imaging (MRI) in differentiation between radiation effect and persistent tumoral tissue. METHODS: TRAMs were calculated by subtracting three-dimensional T1 MRIs acquired 5 minutes after contrast injection from the images acquired 60-105 minutes later. Red areas were regarded as radiation effect and blue areas as persistent tumoral lesion. Thirty-seven patients with 130 metastatic brain tumors who were treated with Gamma Knife radiosurgery and who underwent TRAMs perfusion-weighted MRI were enrolled in this retrospective study. RESULTS: The median age was 58 years and the most common primary diagnosis was lung cancer (n = 21). The median follow-up period of patients was 12 months. The overall local control rate was 100% at 1 year and 98.9% at 2 years. The median progression-free survival was 12 months. The mean overall survival was 27.3 months. The radiologic and clinical follow-up showed a clinicoradiologic diagnosis of a persistent tumoral lesion in 3 tumors (2.3%) and radiation effect in 127 tumors (97.7%). There was a fair agreement between clinicoradiologic diagnosis and TRAMs analysis (κ = 0.380). The sensitivity and positive predictive value of TRAMs in diagnosing radiation effect were 96.06% and 99.2%, respectively. TRAMs showed comparable results to perfusion-weighted MRI, with a diagnostic odds ratio of 27.4 versus 20.7, respectively. CONCLUSIONS: The presented results show the ability of TRAMs in differentiating radiation effect and persistent tumoral lesions.

Assessment of the Olfactory Function in Patients With Idiopathic Intracranial Hypertension Using the Sniffin' Sticks Test: A Case-Control Study.

OBJECTIVE: Despite the lack of recognition in clinical practice, there is increasing evidence that patients with idiopathic intracranial hypertension may suffer from hyposmia. The current case-control study aims to evaluate olfactory dysfunction in a large series of patients with idiopathic intracranial hypertension. METHODS: All subjects, 44 idiopathic intracranial hypertension patients and 57 healthy controls, underwent olfactory function assessment using standardized "Sniffin' Sticks" test at a tertiary referral center of a university hospital. Threshold, discrimination, identification, and total threshold-discrimination-identification scores have been determined and analyzed statistically. RESULTS: Idiopathic intracranial hypertension patients had significantly lower threshold (6.5 [3.69] vs 8 [1.88], P < .001, 95% CI [-2.250, -0.750]) and threshold-discrimination-identification scores (29.75 [5.56] vs 32.5 [5.25], P = .003, 95% CI [-4.250, -0.750]). Twenty-five patients (57%) were diagnosed with hyposmia. Test scores of patients with active idiopathic intracranial hypertension (n = 18) were not statistically different from patients with inactive disease (n = 26), except for discrimination score (14 [2.50] vs 11 [2.25], P = .005, 95% CI [-3.000, -1.000]). Although idiopathic intracranial hypertension patients with a cerebrospinal fluid opening pressure of ≥330 mmH2 O had lower test scores, the difference was significant only for total threshold-discrimination-identification scores (28.5 [5.50] vs 30.5 [4.38], P = .044, 95% CI [0.750, 5.500]). Multiple regression analysis revealed that test scores were related to disease activity, cerebrospinal fluid opening pressure, papilledema, headache, and medication. CONCLUSION: Our clinical study revealed significant olfactory dysfunction in patients with idiopathic intracranial hypertension compared with healthy controls. Future research should employ larger samples to search for usability of olfactory testing in clinical management of patients with idiopathic intracranial hypertension.