The value of contrast?enhanced T1 mapping technique in differentiating recurrence and radiation necrosis of brain metastases after gamma knife treatment / 中华放射学杂志

Objective To explore the value of contrast?enhanced T1 mapping technique in differentiating between recurrence and radiation necrosis of brain metastases after gamma knife treatment. Methods From March 2016 to June 2017,56 patients with brain metastases treated by gamma knife and confirmed by pathology or follow?up in Shandong Provincial Hospital were prospectively collected. Routine MRI and contrast?enhanced T1 mapping sequence scan were performed. T1 value was obtained 5 mins (T1 5 min) and 60 mins (T1 60 min) after injection of contrast agent. The Differences betweenT1 60 min and T1 5 min (T1 differ) was calculated,and relative cerebral blood volume (rCBV) value was obtained. Patients were divided into radiation necrosis group and tumor recurrence group according to imaging follow?up results or pathological results. Two?sides unpaired t test was used to compare the differences in T1 5 min,T1 60 min,T1 differ and rCBV between the 2 groups. Pearson correlation analysis was used to evaluate the correlation between T1 differ and rCBV, and the receiving operating curve (ROC) was used to evaluate the diagnostic efficiency of MRI quantitative parameters,and Z test was used to compare the differences of area under curve (AUC) between T1 differ and rCBV values. Results Of the 56 patients,27 had tumor recurrence and 29 had radiation necrosis. The differences in T1 5 min,T1 60 min,T1 differ and rCBV between the 2 groups was statistically significant (P<0.05). T1 differ and rCBV values were significantly correlated, r=0.58, P<0.01. The differential diagnosis of AUC between radiation necrosis and tumor recurrence were 0.66,0.73,0.97 and 0.95 respectively in T1 5 min,T1 60 min, T1 differ and rCBV, and there was no significant differences between AUC in T1 differ and rCBV (P=0.274). Conclusion The contrast?enhanced T1 mapping image can be used for differential diagnosis between radiation necrosis and recurrence after gamma knife treatment of brain metastases. T1 differ value has high differential efficiency.

Therapeutic effect of different doses of bevacizumab on radiation brain necrosis / 中华放射医学与防护杂志

Objective To evaluate the efficacy and safety of bevacizumab in the treatment of radiation brain necrosis, and to provide guidance for rational clinical application. Methods A retrospective analysis was made of 14 patients with radiation brain necrosis who had failed to receive mannitol and hormone treatment or had been treated for the first time. All the patients were divided into two groups according to different treatment regimens (5. 0 mg/ kg repeated every 14 d and 7. 5 mg/ kg repeated every 21 d). The changes of enhanced lesions in MRI T1W1 phase and edema in T2W1 phase were compared separately in the two groups. The clinical symptoms, changes of KPS score and adverse drug reactions were recorded. Results Totally 14 patients completed at least two cycles of treatment. After two cycles of treatment, the KPS scores of both groups were improved. The KPS scores of 5. 0 mg/ kg group were increased by 31. 66 points on average compared with those before treatment. The KPS scores of 7. 5 mg/ kg group were increased by 27. 50 points on average compared with those before treatment. The volume of CRN lesions were decreased (46. 0±9. 4)％ (t = 6. 57, P<0. 05) and the volume of edema lesions decreased (68. 9±8. 9)％ (t= 3. 32, P<0. 05) in 5. 0 mg/ kg group. In 7. 5 mg/ kg group, these two parameters were reduced by (53. 9±10. 7)％ (t = 7. 89, P<0. 05 and (77. 1±14. 3)％ (t = 4. 22, P<0. 05), respectively. There was no significant difference in the reduction of the mean volume of CRN lesions and the volume of edema area between the two groups (P>0. 05). In this study, the incidence of adverse events in the 5. 0 mg/ kg group was similar to that in the 7. 5 mg/ kg group, with no significant difference (P> 0. 05). Conclusions Bevacizumab can significantly improve the clinical symptoms and quality of life of patients with radiation brain necrosis. The safety of 5. 0 mg/ kg treatment regimen repeated every 14 d is similar to that of 7. 5 mg/ kg treatment regimen repeated every 21 d, which can be used for reference in the treatment of CRN.

Therapeutic effect of different doses of bevacizumab on radiation brain necrosis / 中华放射医学与防护杂志

Objective@#To evaluate the efficacy and safety of bevacizumab in the treatment of radiation brain necrosis, and to provide guidance for rational clinical application.@*Methods@#A retrospective analysis was made of 14 patients with radiation brain necrosis who had failed to receive mannitol and hormone treatment or had been treated for the first time. All the patients were divided into two groups according to different treatment regimens (5.0 mg/kg repeated every 14 d and 7.5 mg/kg repeated every 21 d). The changes of enhanced lesions in MRI T1W1 phase and edema in T2W1 phase were compared separately in the two groups. The clinical symptoms, changes of KPS score and adverse drug reactions were recorded.@*Results@#Totally 14 patients completed at least two cycles of treatment. After two cycles of treatment, the KPS scores of both groups were improved. The KPS scores of 5.0 mg/kg group were increased by 31.66 points on average compared with those before treatment. The KPS scores of 7.5 mg/kg group were increased by 27.50 points on average compared with those before treatment. The volume of CRN lesions were decreased(46.0±9.4)%(t=6.57, P<0.05) and the volume of edema lesions decreased(68.9±8.9)%(t=3.32, P<0.05) in 5.0 mg/kg group. In 7.5 mg/kg group, these two parameters were reduced by(53.9±10.7)%(t=7.89, P<0.05 and (77.1±14.3)%(t=4.22, P<0.05), respectively. There was no significant difference in the reduction of the mean volume of CRN lesions and the volume of edema area between the two groups (P>0.05). In this study, the incidence of adverse events in the 5.0 mg/kg group was similar to that in the 7.5 mg/kg group, with no significant difference(P>0.05).@*Conclusions@#Bevacizumab can significantly improve the clinical symptoms and quality of life of patients with radiation brain necrosis. The safety of 5.0 mg/kg treatment regimen repeated every 14 d is similar to that of 7.5 mg/kg treatment regimen repeated every 21 d, which can be used for reference in the treatment of CRN.

A Case of Brain Edema Caused by Radiation Necrosis After Stereotactic Radiosurgery Treated with Saireito / 日本東洋医学雑誌

A 60-year-old female patient was treated with gamma knife on the left frontal lobe metastatic brain tumor. After 3 months, the tumor and peri-focal edema turned worse due to radiation necrosis. Despite increasing doses of steroid administration, the deterioration lasted for 6 months. The symptoms and brain edema did not improve for over a year, but we decided to observe the patient without bevacizumab. We performed Methionine-PET to diagnose radiation necrosis of the brain, and confirmed absence of hot spots. The steroid therapy continued and added saireito 9 g/day, because we thought brain edema was concerned with fluid retention. After 9 months, head MRI showed improvements of the brain edema. Saireito may help improve brain edema due to radiation necrosis.

Pontine Necrosis Related with Radiation Therapy, Complicated with Spontaneous Hemorrhage

The brain necrosis induced by radiation therapy (RT) is an uncommon pathology of brain. A case of spontaneous hemorrhage at necrotic brain is also rare. A 52-year-old man who had nasopharyngeal carcinoma and had been treated with RT, presented with gait disturbance, dizziness, ataxia, dysarthria, and dysphagia. Magnetic resonance imaging (MRI) demonstrated progressed radiation necrosis of pons, and spontaneous hemorrhage at the site of necrosis. The hematoma was diminished by conservative treatment. However, the patient’s neurologic symptoms did not recover. Two years later, spontaneous bleeding recurred at necrotic brain. His neurologic symptoms worsened. One year later, his neurologic symptoms were more progressed. He showed severe dysphagia, profound weakness and respiratory failure. This case provides the description of relapsed spontaneous hemorrhage and medullary dysfunction caused by pontine necrosis and progressed post-radiation injury, complicated with hemorrhage, and urges caution in that the necrotic brain tissue may be vulnerable to bleeding.

The Use of MR Perfusion Imaging in the Evaluation of Tumor Progression in Gliomas

OBJECTIVE: Diagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients. METHODS: An institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed. MRP was evaluated in its ability to predict tumor progression, defined clinically or radiographically, at concurrent clinical visit and at follow up visit. The data was then analyzed based on glioma grade and subtype. RESULTS: A total of 337 scans and associated clinical visits were reviewed from 64 patients. Sensitivity, specificity, positive and negative predictive value were reported for each tumor subtype and grade. The sensitivity and specificity for high-grade glioma were 60.8% and 87.8% respectively, compared to low-grade glioma which were 85.7% and 89.0% respectively. The value of MRP to assess future tumor progression within 90 days was 46.9% (sensitivity) and 85.0% (specificity). CONCLUSION: Based on our retrospective review, we concluded that adjunct imaging modalities such as MRP are necessary to help diagnose clinical disease progression. However, there is no clear role for stand-alone surveillance MRP imaging in glioma patients especially to predict future tumor progression. It is best used as an adjunctive measure in patients in whom progression is suspected either clinically or radiographically.

Preliminary efficacy of bevacizumab for cerebral radiation necrosis / 中华放射肿瘤学杂志

Objective To evaluate the preliminary clinical efficacy of bevacizumab for cerebral radiation necrosis (CRN). Methods Nineteen patients with CRN for whom the treatment with steroids and mannitol failed were retrospectively analyzed with a total of 22 lesions. Except for 5 lesions confirmed by pathological evidence, all lesions were confirmed by the following imaging evidence:1. computed tomography (CT)?or magnetic resonance imaging (MRI)?enhanced lesions showed loss of tension and were accompanied by substantial edema;2. CT?or MRI?enhanced lesions had a low perfusion pressure;3. magnetic resonance spectroscopy indicated that the enhanced areas had a decreased choline peak; 4. positron emission tomography showed that the fluorodeoxyglucose uptake was substantially reduced in the enhanced areas. All patients were given 5 mg/ kg bevacizumab at an interval of 14 days for 2?6 cycles. MRI examination was performed in each cycle before treatment, and the enhanced lesions on T1?weighted images ( T1 WI) and edema on T2?weighted images (T2 WI) were compared before and after treatment. The clinical symptoms, Karnofsky Performance Status ( KPS), and adverse reactions in all patients were evaluated. Comparison before and after treatment was performed by paired t test. Results All 19 patients completed the treatment successfully and there were no severe adverse reactions. The clinical symptoms of patients were substantially improved after the second cycle of treatment, and the KPS score increased by 26?? 8 on average. The visible volume of enhanced lesions on MRI T1 WI was significantly reduced by 54?? 8% after treatment (P= 0?? 000), while the visible volume of edema on MRI T2 WI was reduced by 80?? 7% after treatment (P= 0?? 000). The follow?up time ranged from 3 to 12 months with a mean value of 5?? 6 months. Eleven patients kept clinical improvement in CRN, four patients had recurrence, and four patients died from tumor progression. Conclusions Bevacizumab is preliminarily confirmed to substantially improve the clinical symptoms and quality of life in patients with CRN.

Radiation-Induced Intratumoral Necrosis and Peritumoral Edema after Gamma Knife Radiosurgery for Intracranial Meningiomas

OBJECTIVE: To study the clinical significance and relevant factors of radiation-induced intratumoral necrosis (RIN) and peritumoral edema (PTE) after Gamma knife radiosurgery (GKRS) for intracranial meningiomas. METHODS: We retrospectively analyzed the data of 64 patients who underwent GKRS for intracranial meningioma. The mean lesion volume was 4.9 cc (range, 0.3-20), and the mean prescription dose of 13.4 Gy (range, 11-18) was delivered to the mean 49.9% (range, 45-50) isodose line. RIN was defined as newly developed or enlarged intratumoral necrosis after GKRS. RESULTS: RIN and new development or aggravation of PTE were observed in 21 (32.8%) and 18 (28.1%) cases of meningioma, respectively during the median follow-up duration of 19.9+/-1.0 months. Among various factors, maximum dose (>25 Gy) and target volume (>4.5 cc) were significantly related to RIN, and RIN and maximum dose (>24 Gy) were significantly related to the development or aggravation of PTE. In 21 meningiomas with development of RIN after GKRS, there was no significant change of the tumor volume itself between the times of GKRS and RIN. However, the PTE volume increased significantly compared to that at the time of GKRS (p=0.013). The median interval to RIN after GKRS was 6.5+/-0.4 months and the median interval to new or aggravated PTE was 7.0+/-0.7 months. CONCLUSION: A close observation is required for meningiomas treated with a maximum dose >24 Gy and showing RIN after GKRS, since following or accompanying PTE may deteriorate neurological conditions especially when the location involves adjacent critical structures.

Radiation-induced brain injury: retrospective analysis of twelve pathologically proven cases

PURPOSE: This study was designed to determine the influencing factors and clinical course of pathologically proven cases of radiation-induced brain injury (RIBI). MATERIALS AND METHODS: The pathologic records of twelve patients were reviewed; these patients underwent surgery following radiotherapy due to disease progression found by follow-up imaging. However, they were finally diagnosed with RIBI. All patients had been treated with 3-dimensional conventional fractionated radiotherapy and/or radiosurgery for primary or metastatic brain tumors with or without chemotherapy. The histological distribution was as follows: two falx meningioma, six glioblastoma multiform (GBM), two anaplastic oligodendroglioma, one low grade oligodendroglioma, and one small cell lung cancer with brain metastasis. RESULTS: Radiation necrosis was noted in eight patients and the remaining four were diagnosed with radiation change. Gender (p = 0.061) and biologically equivalent dose (BED)3 (p = 0.084) were the only marginally influencing factors of radiation necrosis. Median time to RIBI was 7.3 months (range, 0.5 to 61 months). Three prolonged survivors with GBM were observed. In the subgroup analysis of high grade gliomas, RIBI that developed or =6 months (p = 0.085). CONCLUSION: Our study demonstrated that RIBI could occur in early periods after conventional fractionated brain radiotherapy within normal tolerable dose ranges. Studies with a larger number of patients are required to identify the strong influencing factors for RIBI development.

A Case with Cerebral Radiation Necrosis Mimicking Recurrent Brain Tumor

Regardless of an appropriate radiation therapy administered to a patient with a brain tumor, clinical and radiological evidence of progression may still develop because of a recurrence of the tumor and/or radiation necrosis, or even rarely, a radiation induced neoplasm. The evaluation of tumor recurrence and radiation-induced necrosis presents a diagnostic challenge. A thirty eight year old woman was treated for a focal motor seizure on the right side of her face.with a fractionated external beam radiotherapy under the impression of cystic astrocytoma in the left frontoparietal region. After 6 months, she developed a headache, nausea and vomiting, dysphagia, and secondary generalized seizure. A follow-up brain MRI showed a high signal mass lesion in a T2 weighted image and a fluorodeoxyglucose PET revealed hypometabolism in the left frontoparietal lobe, suggesting radionecrosis. It was confirmed as radionecrosis with an expanding edema by open biopsy. We report a cerebral radiation necrosis mimicking recurrent brain tumor.

Differentiation of Cerebral Radiation Necrosis from Tumor Recurrence in Patients with Malignant Gliomas Using 18F-FDG Positron Emission Tomography

The authors evaluated the usefulness of the positron emission tomography(PET) with fluorine-18-fluorodeoxy-glucose(18F-FDG) in diagnosing tumor recurrence and differentiating it from radiation necrosis following external beam irradiation of malignant gliomas. Patients were studied from the time they had first exhibited either clinical or radiological deterioration after an initial period of posttreatment stabilization. Ten studies were performed in ten patients, and 18F-FDG uptake by the lesion was then compared to uptake by adjacent normal gray matter. Four of ten cases demonstrated newly enhanced lesions on magnetic resonance imaging(MRI) and hypermetabolic foci in the PET examinations. All of these patients were diagnosed as tumor recurrence either clinically or histologically, during follow up period of the patients' progress. The remaining six cases had newly enhanced lesions on MRI and hypometabolic foci in the PET studies; five of them were diagnosed as radiation necrosis, but one lesion (0.8cm in diameter) was diagnosed clinically as a tumor recurrence. The overall accuracy of the PET study in differentiating the tumor recurrence from radiation necrosis was 90% and the sensitivity for detection of recurrence 80%. The authors conclude that the PET study with 18F-FDG is useful in differentiating the tumor recurrence from radiation necrosis in patients with malignant glioma and could be used to select the group of patients who may have benefits from antitumor therapy.

An Integrated Logistic Formula for Dose Prescription in Radiosurgery

Radiation necrosis is the main obstacle for radiosurgery delivering high dose ionizing radiation inhomogeneously into small field of lesion with spatial accuracy. The complication probability is closely related to dose-volume effect. To reduce the complication rate, the optimum dose should e prescribed for the isodose curve enclosing the target lesion according to the lesion volume and isodose fall-off. However, the shape, volume and isodose fall-off of the lesions are different from each other. To choose the optimum doses for radiosurgery in each case, it is necessary to have a reasonable model for predicting dose-volume effects. Flickinger developed an integrated logistic formula using normalized total dose(NTD) as a reasonable model to predict complications from gamma knife radiosurgery. The authors developed a computer program to calculate the risk probability using that formula. As previously emphasized, the risk probability derived from the formula is useful and indispensable as a guidance to dose prescription in gamma knife surgery.

Delayed Radiation Necrosis in Both Temporal Lobes: A Case Report

The incidence of delayed radiation necrosis is reported to be 0.5% to 5%. Recently, the incidence of delayed radiation necrosis has been increasing due to three major causes. Firstly, the radiation dose is increasing to treat malignant brain tumors aggressively. Secondly, new diagnostic tools such as high resolution brain CT and magnetic resonance imaging enable the precise detection. Finally, survival time after radiation therapy is prolonged so that delayed radiation effect comes out. We experienced one case of delayed radiation necrosis at the temporal lobes after total 11,000 rads irradiation for nasopharyngeal cancer. We report this case with brief reviews of the articles.

Delayed Radionecrosis of the Brain: A case simulating recurrent glioma

An appreciation of the radiation changes in the brain adjacent to radiated glioma is of considerable importance from both clinical and pathological standpoint because the alteration in the brain parenchyma may result in a picture that mimics recurrence of the neoplasm. A 35 years old woman was admitted because of deterioration of consciousness which has started about 20 days ago. Past history revealed removal of left frontal brain tumor 4 years earlier and the diagnosis was grade II astroma. Postoperative radiation was done at that time. Sine then, she has been doing well. Computerized tomogram showed an ill defined huge low density mass at right frontal and left posterior parietal areas, which was irregularly enhanced in postcontrast study. Unlikely to the usual brain tumors, there was no mass effect on adjacent structures. Histologically acellular necrotic zone was alternating with hypercellular zone and most striking changes were vascular and glial reaction. Most of the vessels showed acellular hyliane thickening of their wall and some vessels were almost completely occluded. There was marked glial proliferation with considerable cellular and nuclear irregularities. Gemistocytic astrocytes were frequently seen and some were multinucleated.