• Radiation Oncology Journal
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• v.27 no.3
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• pp.163-168
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• 2009

Purpose: This study was a retrospective evaluation of the efficacy of stereotactic radiosurgery (SRS) in patients with >4 metastases to the brain. Materials and Methods: Between January 2004 and December 2006, 68 patients with $\geq$4 multiple brain metastases were included and reviewed retrospectively. Twenty-nine patients received SRS and 39 patients received whole brain radiotherapy (WBRT). Patients with small cell lung cancers and melanomas were excluded. The primary lesions were non-small cell lung cancer (69.0%) and breast cancer (13.8%) in the SRS group and non-small cell lung cancer (64.1%), breast cancer (15.4%), colorectal cancer (12.8%), esophageal cancer (5.1%) in the WBRT group. SRS involved gamma-knife radiosurgery and delivered 10~20 Gy (median, 16 Gy) in a single fraction with a 50% marginal dose. WBRT was delivered daily in 3 Gy fractions, for a total of 30 Gy. After completion of treatment, a follow-up brain MRI or a contrast-enhanced brain CT was reviewed. The overall survival and intracranial progression-free survival were compared in each group. Results: The median follow-up period was 5 months (range, 2~19 months) in the SRS group and 6 months (range, 4~23 months) in the WBRT group. The mean number of metastatic lesions in the SRS and WBRT groups was 6 and 5, respectively. The intracranial progression-free survival and overall survival in the SRS group was 5.1 and 5.6 months, respectively, in comparison to 6.1 and 7.2 months, respectively, in the WBRT group. Conclusion: SRS was less effective than WBRT in the treatment of patients with >4 metastases to the brain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6187-6192
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• 2014

The use of WBRT(whole brain radiation therapy) has increased due to the increase in the incidence of metastatic brain tumors. The development of radiation therapy techniques is expected to improve the quality of life. The VMAT (Volumetric Modulated Arc Therapy) is an excellent treatment technique that can distinguish the dose in each volume. Therefore, this study compared conventional WBRT and VMAT for hair loss according to the scalp dose using a head phantom. The CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage) were measured brain tissue. A 20 percent and 50 percent dose was measured at the scalp, eyeball, lens, and c-spine. Conventional WBRT is excellent at 10 percent of brain tissue. VMAT is far superior at 1000 percent at the other organs. VMAT at the prescribed dose can be used as radiation therapy of metastatic brain tumors with less hair loss.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.385-390
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• 1995

Purpose : To assess the efficacy of craniospinal radiotherapy in patients with acute lymphoblastic leukemia (ALL) experiencing the CNS relapse. Materials and Methods: Thirty ALL patients with relapse in the central nervous system (CNS) were treated with radiotherapy and intrathecal chemotherapy. Age ranged 2 to 46. The number of males and females were all 15. Twenty-two cases were previously treated with presymptomatic radiotherapy to the whole brain. The extent of radiotherapy was the whole brain (18-24 Gy) and the whole spine (12 Gy) in 21 cases but the whole brain only in the 9 cases with poor performance. Results : The complete remission rate in the CNS was $100{\%}$. Among the 12 cases ($40{\%}$) who had secondary relapse, 9 cases had the bone marrow relapse alone, 2 cases had the CNS and bone marrow relapse, 1 cases had the CNS relapse alone. Higher CNS remission rate was observed when the initial remission duration was longer than 24 months or radiation was delivered to the whole brain and the whole spine. Survival rate at 2 year was $31.6{\%}$. Remission duration in the 10 living patients ragned from 9 to 87 months (median; 58 months).

• Radiation Oncology Journal
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• v.6 no.2
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• pp.169-176
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• 1988

A retrospective study was performed on 15 patients with suprasellar germ cell tumors treated by megavoltage external beam irradiation between Feb. 1979 and Dec. 1985. Follow-up period of survivors was 30 to 91 months. Histologic diagnosis was obtained before radiation therapy in 10patients (9 germinomas and 1 mixed). Five patients were treated without histologic verification. In 9 patients with biopsy-proven germinomas radiation therapy was delivered to the craniospinal axis in 6, to the whole brain in 3. In 5 patients with mixed germ cell tumor or elevated tumor marker, irradiation was delievered to the craniospinal axis in 2, to the whole brain in 2, and to the primary site only in 1. Total doses ranged from 5,000 to 5,500 cGy to the primary site, 3,000 to 4,400 cGy to the whole brain, and 1,300 to 3,000 cGy to the spine. In these 14, local tumor was controlled and primary or spinal failure was not observed. One patient without elevated tumor marker was treated to the whole brain. The tumor was not controlled and he had spinal recurrence. Overall survival and disease-free survival rates were $86\%$ at 5 year. It is proven that radiation therapy is an effective treatment for suprasellar germ cell tumors. The neuroendocrinologic presentation, tumor marker status, early response to radiation measured on CT seem to be useful means for selecting patients for radiation therapy when tissue diagnosis is not available.

• Radiation Oncology Journal
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• v.15 no.1
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• pp.11-18
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• 1997

Purpose : To evaluate the efficacy of combined treatment of surgery and chemoradiotherapy for supratentorial primitive neuroectodermal tumors (SPNET) and obtain the Prognostic factors and complications Materials and Methods .The a9e of 18 patients ranged from 1 to 27 years (median=5 years). There were 12 males and 6 females The extents of surgery were gross total (n:9), subtotal (n:8), biopsy only (n: 1). Craniospinal radiotherapy was delivered to all the patients except 2 patients who were treated only with the whole brain and primary lesion. Radiation dose were 3120-5800cGy (median=5460) to primary mass, 1500-4200cGy (median=3600cGy) to the whole brain and 1320-3600cGy (median= 2400 cGy) to the spinal axis. Chemotherapy was done in 13 patients. Median follow-up period was 45 months ranged from 1 to 89 months. Results : Patterns of failure were as follows; local recurrence (1), multiple intracranial recurrence (2), spinal seeding (3), craniospinal seeding (2) and multiple bone metastasis (1). Two of two patients who did not received craniospinal radiotherapy failed at spinal area. All the relapsed cases died at 1 to 13 months after diagnosis of progression. The 2- and 5-rear overall survival rates were $61\%\;and\;49\%$, respectively The a9e, sex, tumor location did not influence the survival but aggressive resection with combined chemotherapy showed better outcome. Among 9 survivors, complications were detected as radiation necrosis (n=1), hypopituitarism (n=2), cognitive defect(n=1), memory deficit (n=1), growth retardation (n=1). Conclusion : To improve the results of treatment of SPNET, maximal surgical resection followed by radiation therapy and chemotherapy is necessary. The extended radiation field including craniospinal axis may reduce the recurrence in spinal axis.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.99-105
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• 2010

Purpose: To compare radiation dose of the brain and lens among various conventional whole brain radiotherapy (WBRT) techniques. Materials and Methods: Treatment plans for WBRT were generated with planning computed tomography scans of 11 patients. A traditional plan with an isocenter located at the field center and a parallel anterior margin at the lateral bony canthus was generated (P1). Blocks were automatically generated with a 1 cm margin on the brain (5 mm for the lens). Subsequently, the isocenter was moved to the lateral bony canthus (P2), and the blocks were replaced into the multileaf collimator (MLC) with a 5 mm leaf width in the craniocaudal direction (P3). For each patient plan, 30 Gy was prescribed at the isocenter of P1. Dose volume histogram (DVH) parameters of the brain and lens were compared by way of a paired t-test. Results: Mean values of $D_{max}$ and $V_{105}$ of the brain in P1 were 111.9% and 23.6%, respectively. In P2 and P3, $D_{max}$ and $V_{105}$ of the brain were significantly reduced to 107.2% and 4.5~4.6%, respectively (p<0.001). The mean value of $D_{mean}$ of the lens was 3.1 Gy in P1 and 2.4~2.9 Gy in P2 and P3 (p<0.001). Conclusion: WBRT treatment plans with an isocenter located at the lateral bony canthus have dosimetric advantages for both the brain and lens without any complex method changes.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.125-138
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• 1998

Purpose : To evaluate the late effect(3 and 6 months) of cis-diarnrninedichlo-roplatinum(II)(cisplatin) on the radiation brain damage when the cisplatin was intraperitoneally infused immediately after whole brain irradiation in the rats. Materials and Methods : The histolopathological findings of the brain were examined in rat brains at 3 and 6 months after the treatment. The rats were irradiated(20 or 22.5 Gy, RT) or cisplatin was injected intraperitoneally(2,4, or 8mg/kg, CT) and in combined treatment group, cisplatin(2mg/kg) was injected immediately after irradiation(20 or 22.5 Gr). Histopathological examination was done mostly in irradiation or cisplatin alone groups, because the rats in combined group died during experimental period except 2 rats. Results : The rats treated with cisplatin showed marked epithelial vacuolation with perivascular edema and vascular dilatation in choroid plexus at 3 months as well as multifocal necrosis involving fimbria and cerebellar hemispheres at 3 and 6 months. The changes were more prominent in rats with 2mg/kg injection compared to rats with 8mg/kg injection. The rats with RT and combined CT and RT showed characteristic delayed irradiation effects such as focal coagulation necrosis and vascular changes, which were more marked than previous reports Prominent perivascular and leptomenin-geal astrocytic Proliferation was well documented by anti-GFAP antibody. Cisplatin treatment did not enhance the effect of radiation-induced changes of blood vessels and astrocytic proliferation. Conclusion : The focal necrosis was the most consistently noted finding in this study, it suggested the possibility to use this as an evaluation factor for combined effects of RT and cisplatin.

• Progress in Medical Physics
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• v.26 no.3
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• pp.137-142
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• 2015

We retrospectively analyzed the outcomes in patients who underwent reirradiation for brain metastasis. Twenty-three patients with brain metastases who were initially treated with palliative brain radiotherapy and were retreated with a second course of brain RT between June 2008 and December 2012. WBRT, 3DCRT and SRS were used for brain metastasis. The median dose of the first course of WBRT was 30 Gy (range, 23.4~30 Gy). The dose of the first course 3DCRT for lesion was 30 Gy in 3 Gy per fraction. The median dose of the first course of SRS was 16 Gy in 1 fraction (range, 12~24 Gy). The median dose of the second course of WBRT was 27.5 (range, 12~30 Gy). The median dose of the second course of 3DCRT for lesion was 30 Gy (range, 25~30 Gy). The dose of the second course of SRS was 16 Gy in 1 fraction. The second course of WBRT was administered on radiographic disease progression with symptom in all patients. With median follow-up of 25 months, overall symptom resolution rates were 47.8%. Rate of palliative efficacy was 82.6% including stable disease. The median survival time after initiation of reirradiation was 3.2 months. Median value of KPS prior to reirradiation was 30. Median value of KPS after reirradiation was 60. Reirradiation of brain metastasis maybe feasible and effective in select patients with a good performance status $KPS{\geq}60$ (: ECOG 0~2) prior to reirradiation.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.177-184
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• 1991

From December 1984 to February 1990, 16 patients with tumors of pineal and suprasellar location were treated with radiation therapy. Tissue diagnoses were obtained before radiation therapy in 5 patients and 11 were irradiated without histologic confirmation. Initial treatments for these patients were craniospinal plus boost primary irradiation(six), whole brain plus boost primary irradiation(nine), primary tumor site irradiation(one). The 5 year actuarial survival rate is $71\%$. Three cases with elevated beta-human chorionic gonadotropin(HCG) responded favorably to radiation, but pineal tumors with elevated alpha-fetoprotein(AFP) did not respond well. Spinal metastasis developed in 2 cases(2/15) with elevated AFP : one received prophylactic spinal irradiation, another did not. Our studies suggest that more aggressive treatment would be necessary in patient with elevated AFP and in this patient, radiation therapy may be initiated without pathologic confirmation. From the result of our study, routine use of prophylactic spinal irrdiation for all patients with pineal region tumor is not indicated and use of prophylactic spinal irradiation is considered for the patients with positive craniospinal fluid cytology, meningeal seeding, disease extension along the ventricular wall and biopsy proven germinoma.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.265-272
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• 2014

Purpose : To reduce the radiation dose to the thyroid that is affected to scattered radiation, the shield was used. And we evaluated the shielding effect for the thyroid during whole brain radiation therapy. Materials and Methods : To measure the dose of the thyroid, 300cGy were delivered to the phantom using a linear accelerator(Clinac iX VARIAN, USA.)in the way of the 6MV X-ray in bilateral. To measure the entrance surface dose of the thyroid, five glass dosimeters were placed in the 10th slice's surface of the phantom with a 1.5 cm interval. The average values were calculated by measured values in five times each, using bismuth shield, 0.5 mmPb shield, self-made 1.0 mmPb shield and unshield. In the same location, to measure the depth dose of the thyroid, five glass dosimeters were placed in the 10th slice by 2.5 cm depth of the phantom with a 1.5 cm interval. The average values were calculated by measured values in five times each, using bismuth shield, 0.5 mmPb shield, self-made 1.0 mmPb shield and unshield. Results : Entrance surface dose of the thyroid were respectively 44.89 mGy at the unshield, 36.03 mGy at the bismuth shield, 31.03 mGy at the 0.5 mmPb shield and 23.21 mGy at a self-made 1.0 mmPb shield. In addition, the depth dose of the thyroid were respectively 36.10 mGy at the unshield, 34.52 mGy at the bismuth shield, 32.28 mGy at the 0.5 mmPb shield and 25.50 mGy at a self-made 1.0 mmPb shield. Conclusion : The thyroid was affected by the secondary scattering dose and leakage dose outside of the radiation field during whole brain radiation therapy. When using a shield in the thyroid, the depth dose of thyroid showed 11~30% reduction effect and the surface dose of thyroid showed 20~48% reduction effect. Therefore, by using the thyroid shield, it is considered to effectively protect the thyroid and can perform the treatment.