ABSTRACT
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.
Subject(s)
Humans , Edema , Follow-Up Studies , Meningioma , Necrosis , Prescriptions , Radiosurgery , Retrospective Studies , Tumor BurdenABSTRACT
OBJECTIVE: The aim of this study is to evaluate the therapeutic effects of gamma knife radiosurgery (GKRS) in patients with multiple brain metastases and to investigate prognostic factors related to treatment outcome. METHODS: We retrospectively reviewed clinico-radiological and dosimetric data of 36 patients with 4-14 brain metastases who underwent GKRS for 264 lesions between August 2008 and April 2011. The most common primary tumor site was the lung (n=22), followed by breast (n=7). At GKRS, the median Karnofsky performance scale score was 90 and the mean tumor volume was 1.2 cc (0.002-12.6). The mean prescription dose of 17.8 Gy was delivered to the mean 61.1% isodose line. Among 264 metastases, 175 lesions were assessed for treatment response by at least one imaging follow-up. RESULTS: The overall median survival after GKRS was 9.1+/-1.7 months. Among various factors, primary tumor control was a significant prognostic factor (11.1+/-1.3 months vs. 3.3+/-2.4 months, p=0.031). The calculated local tumor control rate at 6 and 9 months after GKRS were 87.9% and 84.2%, respectively. Paddick's conformity index (>0.75) was significantly related to local tumor control. The actuarial peritumoral edema reduction rate was 22.4% at 6 months. CONCLUSION: According to our results, GKRS can provide beneficial effect for the patients with multiple (4 or more) brain metastases, when systemic cancer is controlled. And, careful dosimetry is essential for local tumor control. Therefore, GKRS can be considered as one of the treatment modalities for multiple brain metastase.
Subject(s)
Humans , Brain Edema , Brain , Breast , Edema , Follow-Up Studies , Lung , Neoplasm Metastasis , Prescriptions , Radiosurgery , Retrospective Studies , Treatment Outcome , Tumor BurdenABSTRACT
It is well known that suprasternal notch is at the midpoint between the carina and vocal cords. We evaluated the distance from the endotracheal tube tip on the suprasternal notch to upper incisor using flexible lightwand. 97 male(height 155~187 cm) and 100 female(height 144~167 cm) patients of undergoing elective surgery were included in the study. After adjust the lamp of the tracheal lightwand at the tube tip, endotracheal tube was placed under anesthesia at the suprasternal notch using the light glow. The distance between upper incisor to suprasternal notch was recorded. The average distance from upper incisor to suprasternal notch was 20.0(+/-1.0)cm in males, 17.9(+/-0.7)cm in females. We demonstrated that the placing the tracheal tube at the suprasternal notch using lightwand was rapid and reliable method for identification of proper tube positioning. We have shown that securing endotracheal tube at upper incisor 23 cm in males and 21 cm in females are positioned distally.