To irradiate the entire neuroaxis, bilateral parallel opposed brain fields and direct posterior spinal field have been utilized and radiation dose at the junction between abutting fields has been extensilvely studied. And several workable methods were reported to achieve uniform dose at a desired depth at the junction between abutting fields whose central axis are coplanar. But the dose distribution at the junction of orthogonal fields has been a persistent problem in radiation oncology. Author describes a new method to solve the junction problem between abutting fields whose central axis are orthogonal. Author utilized split beam/comllimator rotation or collimator/couch rotation to avoid hot or cold spots that may arise from beam divergence. Author achieved accurate and homogeneous dose distribution by matching the 50% isodose line at the junction between orthogonal central axis beam fields.
Axis, Cervical Vertebra ; Brain ; Craniospinal Irradiation* ; Radiation Oncology

PURPOSE: Firstly, to analyze factors in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma. Secondly, to explore an effective salvage treatment for these relapses. MATERIALS AND METHODS: Two patients who had high-risk disease (T3bM1, T3bM3) were treated with combined chemoradiotherapy. CT-simulation based radiation-treatment planning (RTP) was performed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. RESULTS: Review of radiotherapy portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume. When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. CONCLUSION: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.
Brain ; Chemoradiotherapy ; Craniospinal Irradiation ; Humans ; Medulloblastoma* ; Optic Nerve ; Radiotherapy ; Recurrence*

PURPOSE: In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. MATERIALS AND METHODS: A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetric image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was performed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. RESULTS: CSI in the supine position was successfully performed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The differences between the DRRs and the portal films were less than 3 mm in the vertebral contour. CONCLUSION: CSI in the supine position is feasible in patients who cannot lie on prone position, such as pediatric patients under the age of 4 years, patients with a poor general condition, or patients with a tracheostomy.
Craniospinal Irradiation* ; Fluoroscopy ; Head ; Humans ; Immobilization ; Masks ; Neck ; Prone Position ; Radiography ; Spinal Cord ; Supine Position* ; Tracheostomy

The incidence of leptomeningeal dissemination (LMD) of anaplastic glioma has been increasing. LMD can be observed at the time of initial presentation or the time of recurrence. As a result of both rarity and unusual presentation, a standard therapy has not yet been suggested. In contrast to leptomeningeal carcinomatosis for systemic solid cancers, a relatively prolonged survival is observed in some patients with LMD of anaplastic gliomas. Treatment modalities include whole craniospinal irradiation, intra-cerebrospinal fluid (CSF) chemotherapy, and systemic chemotherapy. In some cases, response to temozolomide (TMZ), with or without combined radiation has been reported. Here, we report two cases of LMD of an anaplastic glioma. In one case LMD presented at the time of diagnosis, and in the other at the time of recurrence after radiation. CSF cytology was positive in both cases, and persisted in spite of intrathecal methotrexate chemotherapy. Later, TMZ was prescribed for progressing brain parenchymal lesions, and both radiological and cytological responses were obtained after oral TMZ treatment.
Brain ; Cerebrospinal Fluid ; Craniospinal Irradiation ; Diagnosis ; Drug Therapy ; Glioma* ; Humans ; Incidence ; Meningeal Carcinomatosis ; Methotrexate ; Recurrence

Malignant CNS lymphoma is a malignant intracranial tumor and in most cases they run a fulminating course if left untreated, with 3 to 5 months survival after appearance of the initial symptoms. Sixteen patients with malignant lymphoma were treated in Asan Medical Center from 1989 to 1994. All patients were underwent tissue diagnosis with subtotal resection or stereotactic biopsy and followed by cranial or craniospinal irradiation with or without systemic chemotherapy. One and three year survival rate of the patients was 88% and 78% respectively. In conclusion, addition of chemotherapy and/or cranial radiation for treatment of the CNS lymphoma may improve survival.
Biopsy ; Chungcheongnam-do ; Craniospinal Irradiation ; Diagnosis ; Drug Therapy ; Humans ; Lymphoma* ; Survival Rate

PURPOSE: To evaluate the possibility of decreasing the radiation dose and to determine optimum treatment volume in intracranial germinomas. MATERIALS AND METHODS: Forty five patients with pathologically-verified or presumed germinomas by a radiosensitivity test who had been treated with radiotherapy (RT) alone between 1971 and 1992 were retrospectively analyzed. The average age was 17.2 years with 68.9% of the patients being between the ages of 10-20. The male and female ratio was 2.2:1. The locations of the primary tumors were at the pineal regions in 14 patients; the suprasellar regions in 12 patients; and multiple sites in 12 patients. Treatment volumes varied from a small local field (10) to the whole brain (7) or entire neuroaxis irradiation(28). All the cases after 1982 received craniospinal irradiation (CSI). Radiation doses were 41-59 Gy (median 48.5 Gy) to the primary tumor site and 19.5-36 Gy (median 24 Gy) to the neuroaxis. The median follow-up period was 82 months with a range of 2-260 months. RESULTS: All the patients showed complete response after RT. Four patients sufferred from recurrence 14, 65, 76, and 170 months after RT, respectively, and two patients died with intercurrent disease. One of four recurrent cases was salvaged by re-irradiation. Therefore, a 5 and 10 year overall survival was 95.3 % and 84.7 % respectively. Five and ten year disease-free survival was 97.6 % and 88.8 % respectively. All the recurrences occurred in the patients who received local RT (3/10) or whole brain RT (1/7) with a radiation dose of 48-50 Gy. None of the patients who received CSI suffered recurrence. There was no recurrence among the 15 patients who received < or = 45 Gy to the primary site and the 18 patients who received < or = 24 Gy (6 patients received 19.5 Gy) to the neuroaxis. CONCLUSION: CSI is recommended for the treatment of intracranial germinomas. The radiation dose can be safely decreased to < or = 45 Gy on a primay tumor site and 19.5 Gy on the spine.
Brain ; Craniospinal Irradiation ; Disease-Free Survival ; Female ; Follow-Up Studies ; Germinoma* ; Humans ; Male ; Radiation Tolerance ; Radiotherapy ; Recurrence ; Retrospective Studies ; Spine

PURPOSE: The purpose of this study is to investigate the long-term results and appropriateness of radiation therapy (RT) for medulloblastoma (MB) at a single institution. MATERIALS AND METHODS: We analyzed the clinical outcomes of 106 patients with MB who received RT between January 1992 and October 2009. The median age was 7 years (range, 0 to 50 years), and the proportion of M0, M1, M2, and M3 stages was 60.4%, 8.5%, 4.7%, and 22.6%, respectively. The median total craniospinal irradiation (CSI) and posterior fossa tumor bed dose in 102 patients (96.2%) treated with CSI was 36 Gy and 54 Gy, respectively. RESULTS: The median follow-up period in survivors was 132 months (range, 31 to 248 months). A gradual improvement in survival outcomes was observed, with 5-year overall survival rates of 61.5% in 1990s increasing to 73.6% in 2000s. A total of 29 recurrences (27.4%) developed at the following sites: five (17.2%) in the tumor bed; five (17.2%) in the posterior fossa other than the tumor bed; nine (31%) in the supratentorium; and six (20.7%) in the spinal subarachnoid space only. The four remaining patients showed multiple site recurrences. Among 12 supratentorial recurrences, five cases recurred in the subfrontal areas. Although the frequency of posterior fossa/tumor bed recurrences was significantly high among patients treated with subtotal resection, other site (other intracranial/spinal) recurrences were more common among patients treated with gross tumor removal (p=0.016). There was no case of spinal subarachnoid space relapse from desmoplastic/extensive nodular histological subtypes. CONCLUSION: Long-term follow-up results and patterns of failure confirmed the importance of optimal RT dose and field arrangement. More tailored multimodal strategies and proper CSI technique may be the cornerstones for improving treatment outcomes in MB patients.
Combined Modality Therapy* ; Craniospinal Irradiation ; Follow-Up Studies* ; Humans ; Infratentorial Neoplasms ; Medulloblastoma* ; Radiotherapy ; Recurrence ; Subarachnoid Space ; Survival Rate ; Survivors

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 10%. 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 case 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 ranged from 9 to 87 months(median ; 58 months). CONCLUSION: The whole craniospinal area should be included in the radiotherapy port for the effective control of CNS relapse in ALL cases
Bone Marrow ; Brain ; Craniospinal Irradiation ; Drug Therapy ; Female ; Humans ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Radiotherapy* ; Recurrence* ; Spine ; Survival Rate

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 10%. 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 case 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 ranged from 9 to 87 months(median ; 58 months). CONCLUSION: The whole craniospinal area should be included in the radiotherapy port for the effective control of CNS relapse in ALL cases
Bone Marrow ; Brain ; Craniospinal Irradiation ; Drug Therapy ; Female ; Humans ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Radiotherapy* ; Recurrence* ; Spine ; Survival Rate

A retrospective analysis was performed on 23 patients with pineal region tumors treated with radiation from 1979 through 1985 at the Department of Therapeutic Radiology, Seoul National University Hospital, Histologic confirmation was done in only one case by surgical removal, and in the remaining 22 patients, the diagnosis was based on clinical and radiological findings. The radiation volume was the primary tumor site in 1 case, whole brain in 14 cases, and the whole craniospinal axis in 8 cases. The overall 5 year survival was 71.5%. The 5 year survival was 69. 3% for whole brain treated group and 73.3% for craniospinal axis treated group. The survival for the two groups did not differ significantly. In two cases sites of recurrence were detected. One in supratentorial area, and the other in the lung. The results from this retrospective analysis and the review of other reports indicate that routine use of prophlatic spinal irradiation is not warranted in pineal region tumor, and the craniospinal irradiation is recommended in cases with high risk for subarachnoid seeding such as positive CSF cytology, surgical removal or biopsy.
Axis, Cervical Vertebra ; Biopsy ; Brain ; Craniospinal Irradiation ; Diagnosis ; Humans ; Lung ; Pinealoma* ; Radiation Oncology ; Radiotherapy* ; Recurrence ; Retrospective Studies ; Seoul