PURPOSE: Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plans for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decided. MATERIALS AND METHODS: Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal tumor-5.7x8.2x7.6 cm, suprasellar tumor-3x4x4.1 cm, thalamic tumor-3.1x5.9x3.7 cm, frontoparietal tumor-5.5x7x5.5 cm, and occipitoparietal tumor-5x5.5x5 cm. Plans using parallel opposed 2 portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. RESULTS: 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D plans : 27%, 8% 3D plans : 1%, 1%). Various dose statistic values did not show any consistent trend. A 3D plan using 3 noncoplanar portals was selected as a model radiotherapy plan. 2) Suprasellar tumor; NTCPs of all 3D plans and 2D plans did not show significant difference because the total dose of this tumor was only 54 Gy. DVHs of normal brain and brainstem were significantly different for different plans. D5, V85, V95 and mean values showed some consistent trend that was compatible with DVH. All 3D plans were superior to 2D plans even when 3 portals (fronto-vertex and 2 lateral fields) were used for 2D plans. A 3D plan using 7 portals was worse than plans using fewer portals. A 3D plan using 5 noncoplanar portals was selected as a model plan. 3) Thalamic tumor; NTCPs of all 3D plans were lower than the 2D plans when the total dose was elevated to 72 Gy. DVHs of normal tissues showed similar results. V83, V85, V95 showed some consistent differences between plans but not between 3D plans. 3D plans using 5 noncoplanar portals were selected as a model plan. 4) Parietal (fronto- and occipito-) tumors; all NTCPs of the normal brain in 3D plans were lower than in 2D plans. DVH also showed the same results. V83, V85, V95 showed consistent trends with NTCP and DVH. 3D plans using 5 portals for frontoparietal tumor and 6 portals for occipitoparietal tumor were selected as model plans. CONCLUSION: NTCP and DVH showed reasonable differences between plans and were thought to be useful for comparing plans. All 3D plans were superior to 2D plans. Best 3D plans were selected for tumors in each site of brain using NTCP, DVH and finally by the planner's decision.
Brain Neoplasms* ; Brain Stem ; Brain* ; Humans ; Rabeprazole ; Radiotherapy ; Radiotherapy, Conformal*

No abstract available.
Brain Neoplasms ; Child* ; Humans ; Radiotherapy

Whole brain irradiation is one mode in the treatment of brain cancer and brain metastasis, but it might cause brain injury such as brain necrosis. It has been studied whether the dose distribution could be a cause of brain injury. The dose distribution in whole brain irradiated by Co-0 beam has been measured by means of calibrated TLD chips inserted in the brain of Humanoid phantom. The following results were obtained. 1. Dose distribution on each transverse section of the brain was uniform. 2. On the midsagital plane of the brain, the dose was highest in upper portion and lowest in lower portion, varying 8 from 104% to 90%. 3. When the radiation field includes free space of 2cm or more width out of the head, the dose distribution in the whole brain is almost independent of the field width. 4. It is important to determine adequate shielding area and to set shielding block exactly in repetition of treatment.
Brain Injuries ; Brain Neoplasms ; Brain* ; Head ; Necrosis ; Neoplasm Metastasis ; Radiotherapy*

In this paper, two new concepts of DR (Dose Repulsion) and DG (Dose Gravitation) are presented with their calculation formulas. For the problem of selecting beam arcs in x-knife radiotherapy Planning system, a mathematics model of constrained optimization has been built. Furthermore, we have produced a feasible project of automatic selecting optimized beam arcs plan using SA (Simulated Annealing) arithmetic based on the distribution of the fields of DR and DG in the reduced phase space.
Algorithms ; Brain Neoplasms ; radiotherapy ; Models, Theoretical ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Conformal ; methods

Brachytherapy ; methods ; Brain Neoplasms ; radiotherapy ; Glioma ; radiotherapy ; Humans ; Iodine Radioisotopes ; therapeutic use ; Liver Neoplasms ; radiotherapy ; Lung Neoplasms ; radiotherapy ; Male ; Mouth Neoplasms ; radiotherapy ; Neoplasms ; radiotherapy ; Pancreatic Neoplasms ; radiotherapy ; Prostatic Neoplasms ; radiotherapy ; Radiotherapy Dosage ; Survival Rate

Fractionation dose and number have been known as radiation factor affecting the radiation complication and the effectiveness in radiotherapy for brain tumors. In this study hyperfractionation technique with 115cGy/fractioin 2 fractions daily 5days/wk, upto 5750-6900cGy to partial brain volume was compared with conventional fractionation technique with daily 200cGy/fraction 5 fraction/wk, upto 5400-6000cGy, in regarding to the effectiveness of hyperfractionated radiotherapy and eraly and later radiation reavtion. The survival period was longer in hyperfractionated irradiated group particularly if the tumors were located in the posterior portion of brain, however there was no singificant statistics due to small number of patients. Mean survival period for glioblastoma multiforme was 11.8 months in hyperfractionated group vs 8.7 months in conventional fractionated group and for high grade astrocytoma 36month in hyperfractionated group, but in conventional fractionated group all was died in 18 months. Acute radiation reaction occurred less frequently in hyperfractionated group, 15.8% vs 47.8% in conventional fractionated group(p<0.024). Alopeci was developed in 31.6% of the hyperfractionated group vs 82.6% of the conventional fractionated group(p<0.0031). One case of later radiation necrosis in cancer region was suspected in the hyperfractionated group but we has been in a dilemma for confirmatory diagnosis in present available diagnostic technique. The hyperfractionated irradiation technique was proven to be superior to conventional fractionated technique regarding the radiation reaction and the effectiveness of the treatment.
Astrocytoma ; Brain ; Brain Neoplasms ; Diagnosis ; Glioblastoma ; Glioma* ; Humans ; Necrosis ; Radiotherapy*

BACKGROUND: Immunotherapy (IT) is recommended for the treatment of advanced non-small cell lung cancer (NSCLC), while brain radiotherapy (RT) is the mainstream treatment for patients with brain metastases (BM). This study aimed to investigate the efficacy and safety of combined use of RT and IT. METHODS: The date was limited to May 1, 2022, and literature searches were carried out in CNKI, Wanfang, PubMed, EMBASE and Cochrane databases. Heterogeneity was judged using the I2 test and P value. Publication bias was assessed using a funnel plot. The quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Statistical analysis was performed using Stata 16.0 software. RESULTS: A total of 17 articles involving 2,636 patients were included. In the comparison of RT+IT group and RT group, no significant difference was found in overall survival (OS) (HR=0.85, 95%CI: 0.52-1.38, I2=73.9%, Pheterogeneity=0.001) and intracranial distance control (DBC) (HR=1.04, 95%CI: 0.55-1.05, I2=80.5%, Pheterogeneity<0.001), but the intracranial control (LC) in the RT+IT group was better than the RT group (HR=0.46, 95%CI: 0.22-0.94, I2=22.2%, Pheterogeneity=0.276), and the risk of radiation necrosis/treatment-related imaging changes (RN/TRIC) was higher than RT (HR=1.72, 95%CI: 1.12-2.65, I2=40.2%, Pheterogeneity=0.153). In the comparison between the RT+IT concurrent group and the sequential group, no significant difference was found in OS (HR=0.62, 95%CI: 0.27-1.43, I2=74.7%, Pheterogeneity=0.003) and RN/TRIC (HR=1.72, 95%CI: 0.85-3.47, I2=0%, Pheterogeneity=0.388) was different between the two groups. However, DBC in the concurrent treatment group was better than that in the sequential treatment group (HR=0.77, 95%CI: 0.62-0.96, I2=80.5%, Pheterogeneity<0.001). CONCLUSIONS RT combined with IT does not improve the OS of NSCLC patients with BM, but also increases the risk of RN/TRIC. In addition, compared with sequential RT and IT, concurrent RT and IT improved the efficacy of DBC.
Humans ; Lung Neoplasms/radiotherapy* ; Carcinoma, Non-Small-Cell Lung/radiotherapy* ; Brain Neoplasms/radiotherapy* ; Immunotherapy/methods* ; Radiation Injuries

For the QA of IMRT treatment of head and neck cancer by using M3 (BrainLAB Inc. Germany), it is not easy to measure delivery dose exactly because the dose attenuation appears by the couch according to the position of table and gantry. In order to solve this problem, we fabricated head and neck phantom which would be implemented on the couch mount of Brain Lab Inc. We investigated dose attenuation by the couch and found the difference of dose distribution by the couch, in the applying this phantom to the clinic. After measurement, we found that point dose attenuation was 35% at maximum and dose difference was 5.4% for a point dose measurement of actual patient quality assurance plan.
Brain ; Head and Neck Neoplasms ; Head* ; Humans ; Neck* ; Radiotherapy*

PURPOSE: To evaluate the clinical results of stereotactic radiosurgery (SRS) and frac- tionated stereotactic radiotherapy (FSRT) for metastatic brain tumors. MATERIALS AND METHODS: Nineteen patients with brain metastases (34 lesions) were treated with LINAC-based SRS or FSRT with or without whole brain radiotherapy between October 1995 and February 1998. SRS was preferred to FSRT in cases with three or more lesions and poor performance status. FSRT was preferred to SRS in cases with lesions larger than 3 cm and lesions located near or at the eloquent areas such as thalamus, brain stem, and optic apparatus. Single isocenter was used both in SRS and FSRT, and the median peripheral dose in SRS was 15 Gy (range 13~20 Gy), while that in FSRT was 21 Gy (range 15~24 Gy) by 3 Gy per fraction. RESULTS: Local control was achieved in 79% (27/34 treated lesions) and 1-year over- all survival rate was 58% with the median survival of 12 months. Lethal progressive brain metastases, both local and regional, were in four patients (27% of all deaths). No significant differences in local control and survival was observed with histology, age, sex, performance status, tumor volume, number of lesions, or treatment modality. Unacceptable acute or late complications did not occur. CONCLUSION: Stereotactic radiotherapy including SRS and FSRT is effective, non-invasive therapy for brain metastases. This study suggests that stereotactic radiotherapy might be an alternative to surgical resection in selected patients of brain metastases.
Brain Neoplasms ; Brain Stem ; Brain* ; Humans ; Neoplasm Metastasis* ; Radiosurgery ; Radiotherapy* ; Survival Rate ; Thalamus ; Tumor Burden

PURPOSE: To evaluate the role of fractionated stereotactic radiotherapy (FSRT) in the management of benign brain tumors, we reviewed the clinical, and radiographic responses of patients treated. METHODS AND MATERIALS: Between March 1996 and March 2002, 36 patients with benign brain tumors were treated by FSRT. The pathological diagnoses consisted of pituitary adenomas (12 patients), craniopharyngiomas (5 patients), meningiomas (10 patients), and acoustic neurinomas (9 patients). Radiotherapy doses of 25 to 35 Gy (3~6 Gy/fraction, 5~10 fractions) were prescribed to the 85~90% isodose line, depending upon the location, size and volume of the tumors. The median clinical and radiographical follow- up periods were 31 (range, 2~74) and 21 (range, 4~56) months, respectively. RESULTS: In the 35 patients that could be evaluated for their clinical response, 13 (37.1%) were considered improved, 16 (45.7%) stable and 6 (17.2%) worse. Of the 33 patients who had radiographic studies, tumor shrinkage was noted in 17 (51.5%), tumor stabilization in 13 (39.4%), and tumor progression in 3 (9.1%). Of the 17 tumor shrinkage patients, 7 (21.2%) showed a complete response. Acute radiation-induced complications occurred in 11 (30.6%) patients. CONCLUSION: FSRT is considered a safe and effective treatment method for benign brain tumors, but large numbers of patients, with relatively long follow-up periods are needed to assess the exact role or effect of FSRT.
Brain Neoplasms* ; Brain* ; Craniopharyngioma ; Diagnosis ; Follow-Up Studies ; Humans ; Meningioma ; Neuroma, Acoustic ; Pituitary Neoplasms ; Radiotherapy*