MR Imaging Response of Brain Metastases after Gamma Knife Stereotactic Radiosurgery

Peterson, AM; Meltzer, Carolyn C.; Evanson, E J; Flíckinger, John C.; Kondziolka, Douglas

doi:10.1148/radiology.211.3.r99jn48807

Cited by 90 publications

(53 citation statements)

References 32 publications

(57 reference statements)

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“…Radiation injury (eg, radiation necrosis) on follow-up standard MRI is characterized by alterations in T2-weighted images and changing patterns of contrast enhancement and is often indistinguishable from local tumor recurrence. [32][33][34] The current gold standard for distinguishing tumor recurrence from radiation injury remains biopsy, which has an accuracy rate >95%. 35,36 Biopsy, however, is invasive, can yield false-negative results, and has potential complications such as infection, procedure-associated new neurological problems, and hematoma-although the risk of permanent complications is relatively low.…”

Section: Discussionmentioning

confidence: 99%

DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

et al. 2016

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Background. The aim of this study was to investigate the potential of dynamic O-(2-[ 18 F]fluoroethyl)-L-tyrosine ( 18 F-FET) PET for differentiating local recurrent brain metastasis from radiation injury after radiotherapy since contrastenhanced MRI often remains inconclusive. Methods. Sixty-two patients (mean age, 55 ± 11 y) with single or multiple contrast-enhancing brain lesions (n = 76) on MRI after radiotherapy of brain metastases (predominantly stereotactic radiosurgery) were investigated with dynamic 18 F-FET PET. Maximum and mean tumor-to-brain ratios (TBR max , TBR mean ) of 18 F-FET uptake were determined (20-40 min postinjection) as well as tracer uptake kinetics (ie, time-to-peak and slope of time-activity curves). Diagnoses were confirmed histologically (34%; 26 lesions in 25 patients) or by clinical follow-up (66%; 50 lesions in 37 patients). Diagnostic accuracies of PET parameters for the correct identification of recurrent brain metastasis were evaluated by receiver-operating-characteristic analyses or the chi-square test. Results. TBRs were significantly higher in recurrent metastases (n = 36) than in radiation injuries (n = 40) (TBR max 3.3 ± 1.0 vs 2.2 ± 0.4, P < .001; TBR mean 2.2 ± 0.4 vs 1.7 ± 0.3, P < .001). The highest accuracy (88%) for diagnosing local recurrent metastasis could be obtained with TBRs in combination with the slope of time-activity curves (P < .001). Conclusions. The results of this study confirm previous preliminary observations that the combined evaluation of the TBRs of 18 F-FET uptake and the slope of time-activity curves can differentiate local brain metastasis recurrence from radiation-induced changes with high accuracy. 18 F-FET PET may thus contribute significantly to the management of patients with brain metastases.

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Section: Discussionmentioning

confidence: 99%

DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

et al. 2016

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“…Today, the use of SRS is a widely accepted treatment option for cerebral metastases (25), either as a single modality or in combination with WBRT. Radiation-induced changes (i.e., radiation necrosis) on follow-up MRI studies including alterations in T2-weighted images and changing patterns of contrast enhancement have been reported in about 20% of all patients and can often not be distinguished from local tumor recurrence (26)(27)(28). The current gold standard for distinguishing tumor recurrence from radiation necrosis remains biopsy, which has an accuracy of more than 95% (29,30).…”

Section: Discussionmentioning

confidence: 99%

Role of O-(2-¹⁸F-Fluoroethyl)-l-Tyrosine PET for Differentiation of Local Recurrent Brain Metastasis from Radiation Necrosis

et al. 2012

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The aim of this study was to investigate the potential of O-(2-18 F-fluoroethyl)-L-tyrosine ( 18 F-FET) PET for differentiating local recurrent brain metastasis from radiation necrosis after radiation therapy because the use of contrast-enhanced MRI for this issue is often difficult. Methods: Thirty-one patients (mean age 6 SD, 53 6 11 y) with single or multiple contrastenhancing brain lesions (n 5 40) on MRI after radiation therapy of brain metastases were investigated with dynamic 18 F-FET PET. Maximum and mean tumor-to-brain ratios (TBR max and TBR mean , respectively; 20-40 min after injection) of 18 F-FET uptake were determined. Time-activity curves were generated, and the time to peak (TTP) was calculated. Furthermore, time-activity curves of each lesion were assigned to one of the following curve patterns: (I) constantly increasing 18 F-FET uptake, (II) 18 F-FET uptake peaking early (TTP # 20 min) followed by a plateau, and (III) 18 F-FET uptake peaking early (TTP # 20 min) followed by a constant descent. The diagnostic accuracy of the TBR max and TBR mean of 18 F-FET uptake and the curve patterns for the correct identification of recurrent brain metastasis were evaluated by receiver-operating-characteristic analyses or Fisher exact test for 2 · 2 contingency tables using subsequent histologic analysis (11 lesions in 11 patients) or clinical course and MRI findings (29 lesions in 20 patients) as reference. Results: Both TBR max and TBR mean were significantly higher in patients with recurrent metastasis (n 5 19) than in patients with radiation necrosis (n 5 21) (TBR max , 3.2 6 0.9 vs. 2.3 6 0.5, P , 0.001; TBR mean , 2.1 6 0.4 vs. 1.8 6 0.2, P , 0.001). The diagnostic accuracy of 18 F-FET PET for the correct identification of recurrent brain metastases reached 78% using TBR max (area under the ROC curve [AUC], 0.822 6 0.07; sensitivity, 79%; specificity, 76%; cutoff, 2.55; P 5 0.001), 83% using TBR mean (AUC, 0.851 6 0.07; sensitivity, 74%; specificity, 90%; cutoff, 1.95; P , 0.001), and 92% for curve patterns II and III versus curve pattern I (sensitivity, 84%; specificity, 100%; P , 0.0001). The highest accuracy (93%) to diagnose local recurrent metastasis was obtained when both a TBR mean greater than 1.9 and curve pattern II or III were present (AUC, 0.959 6 0.03; sensitivity, 95%; specificity, 91%; P , 0.001). Conclusion: Our findings suggest that the combined evaluation of the TBR mean of 18 F-FET uptake and the pattern of the timeactivity curve can differentiate local brain metastasis recurrence from radionecrosis with high accuracy. 18 F-FET PET may thus contribute significantly to the management of patients with brain metastases. The improvement in the treatment of solid tumors has led to an increasing number of patients who experience brain metastases during the course of the disease. Stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT) are commonly used to treat brain metastases, and a growing percentage of patients live long enough to experience a local relapse of these me...

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“…Lesions that showed shrinkage or remained stable on contrast-enhanced, T1-weighted MR imaging after at least 6 mo of follow-up were considered to be LDRI (9-12), whereas lesions that showed increases in volume of 25% or more were considered to represent RPBM (24,25 …”

Section: Final Diagnosis and Follow-up Of Patientsmentioning

confidence: 99%

¹⁸F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment

et al. 2013

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Brain metastases are frequently treated with radiation. It is critical to distinguish recurrent or progressive brain metastases (RPBM) from late or delayed radiation injury (LDRI). The purpose of this study was to examine the diagnostic accuracy as well as the prognostic power of 6-18 F-fluoro-L-dopa ( 18 F-FDOPA) PET for differentiating RPBM from LDRI. Methods: Thirty-two patients who had 83 previously irradiated brain metastases and who underwent 18 F-FDOPA PET because of an MR imaging-based suggestion of RPBM were studied retrospectively. PET studies were analyzed semiquantitatively (lesion-to-striatum and lesion-to-normal brain tissue ratios based on both maximum and mean standardized uptake values) and visually (4-point scale). The diagnostic accuracy of PET was verified by histopathologic analysis (n 5 9) or clinical follow-up (n 5 74) on a lesion-by-lesion basis. Receiver operating characteristic curve analysis was used to identify the best diagnostic indices. The power of 18 F-FDOPA PET to predict disease progression was evaluated with the Kaplan-Meier and Cox regression methods. Results: The best overall accuracy was achieved by visual scoring, with which a score of 2 or more (lesion uptake greater than or equal to striatum uptake) resulted in a sensitivity of 81.3% and a specificity of 84.3%. Semiquantitative 18 F-FDOPA PET uptake indices based on lesion-to-normal brain tissue ratios were significantly higher for RPBM than for LDRI. Among the various predictors tested, 18 F-FDOPA PET was the strongest predictor of tumor progression (hazard ratio, 6.26; P , 0.001), and the lesion-to-normal brain tissue ratio or visual score was the best discriminator. The mean time to progression was 4.6 times longer for lesions with negative 18 F-FDOPA PET results than for lesions with positive 18 F-FDOPA PET results (76.5 vs. 16.7 mo; P , 0.001). 18 F-FDOPA PET findings tended to predict overall survival. Conclusion: Metabolic imaging with 18 F-FDOPA PET was useful for differentiating RPBM from LDRI. Semiquantitative indices, particularly lesionto-normal uptake ratios, could be used. A visual score comparing tumor 18 F-FDOPA uptake and striatum 18 F-FDOPA uptake provided the highest sensitivity and specificity and was predictive of disease progression.

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MR Imaging Response of Brain Metastases after Gamma Knife Stereotactic Radiosurgery

Cited by 90 publications

References 32 publications

DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

Role of O-(2-¹⁸F-Fluoroethyl)-l-Tyrosine PET for Differentiation of Local Recurrent Brain Metastasis from Radiation Necrosis

¹⁸F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment

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MR Imaging Response of Brain Metastases after Gamma Knife Stereotactic Radiosurgery

Cited by 90 publications

References 32 publications

DynamicO-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

DynamicO-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

Role of O-(2-18F-Fluoroethyl)-l-Tyrosine PET for Differentiation of Local Recurrent Brain Metastasis from Radiation Necrosis

18F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment

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DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

DynamicO-(2-¹⁸F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

Role of O-(2-¹⁸F-Fluoroethyl)-l-Tyrosine PET for Differentiation of Local Recurrent Brain Metastasis from Radiation Necrosis

¹⁸F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment