• Progress in Medical Physics
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• v.14 no.2
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• pp.90-98
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• 2003

Purpose : A new virtual simulation technique for craniospinal irradiation (CSI) that uses a CT-simulator was developed to improve the accuracy of field and shielding placement as well as patient positioning. Materials and Methods : A CT simulator (CT-SIM) and a 3-D conformal radiation treatment planning system (3D-CRT) were used to develop CSI. The head and neck were immobilized with a thermoplastic mask while the rest of the body was immobilized with a Vac-Loc. A volumetric image was then obtained with the CT simulator. In order to improve the reproducibility of the setup, datum lines and points were marked on the head and body. Virtual fluoroscopy was performed with the removal of visual obstacles, such as the treatment table or immobilization devices. After virtual simulation, the treatment isocenters of each field were marked on the body and on the immobilization devices at the conventional simulation room. Each treatment fields was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR) and digitally composited radiography (DCR) images from virtual simulation. Port verification films from the first treatment were also compared with the DRR/DCR images for geometric verification. Results : We successfully performed virtual simulations on 11 CSI patients by CT-SIM. It took less than 20 minutes to affix the immobilization devices and to obtain the volumetric images of the entire body. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with simulation films to within 5 mm. This not only reducee inconveniences to the patients, but also eliminated position-shift variables attendant during the long conventional simulation process. In addition, by obtaining CT volumetric image, critical organs, such as the eyes and the spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. Differences between the DRRs and the portal films were less than 3 m in the vertebral contour. Conclusion : Our analysis showed that CT simulation of craniospinal fields was accurate. In addition, CT simulation reduced the duration of the patient's immobility. During the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization by standard protocol for craniospinal irradiation.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.189-193
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• 2009

Purpose: To report on the changes in the patterns of care and survival over time for esthesioneuroblastoma. Materials and Methods: We retrospectively analyzed 42 previously untreated and histologically confirmed esthesioneuroblastoma patients seen between March 1989 and June 2007. According to Kadish's classification, 3 patients (7%) were stage A, 6 (14%) at stage B, and 33 (79%) at stage C. Of the 33 Kadish C patients, 19 and 14 patients were treated from 1989 through 2000 and from 2001 through 2007, respectively. Treatment included surgical resection, radiotherapy, chemotherapy, or a combination of these methods. Chemotherapy was administered to 8 of 19 patients (42%) seen from 1989 through 2000, whereas all of the 14 patients seen from 2001 through 2007 received chemotherapy (p<0.001). No patient was treated by three-dimensional conformal radiotherapy (3D-CRT) from 1989 through 2000, however 8 of 14 patients (67%) seen from 2001 through 2007 underwent 3D-CRT (p<0.001). The median follow-up time for surviving patients was 6.5 years (range, 2.2~15.8 years). Results: The 5-year overall survival (OS) and progression-free survival (PFS) rates for the entire cohort were 53% and 39%, respectively. The 5-year OS was 100% for Kadish stages A or B and 39% for stage C (p=0.007). For patients with stage C disease who were treated from 1989 to 2000 and from 2001 to 2007, the 5-year OS rate was 26% and 59% (p=0.029), respectively and the corresponding 5-year PFS rate was 16% and 46% (p=0.001), respectively. Intraorbital extension and treatment era (1989~2000 vs. 2001~2007) were found as independent factors for OS and PFS in a multivariate analyses. Conclusion: The results of this study suggest that treatment era, which features a distinction in treatment modality and technique with the introduction of 3D-CRT, may be the cause of improved OS and PFS in Kadish stage C patients. To achieve better outcomes for patients with Kadish stage C, combined chemoradiotherapy, especially 3D-CRT, is recommended in addition to surgery.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.37-47
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• 2014

The purpose of this study was to analyze translational and rotational adjustments during automatic rigid image-registration by using different control parameters for a total of five groups on TomoTherapy (Accuray Inc, Sunnyvale, CA, USA). We selected a total of 50 patients and classified them in five groups (brain, head-and-neck, lung, abdomen and pelvic) and used a total of 500 megavoltage computed tomography (MVCT) image sets for the analysis. From this we calculated the overall mean value(M) for systematic and random errors after applying the different control parameters. After randomization of the patients into the five groups, we found that the overall mean value varied according to three techniques and resolutions. The deviation for the lung, abdomen and pelvic groups was approximately greater than the deviation for the brain and head-and-neck groups in all adjustments. Overall, using a "full-image" produces smaller deviations in the rotational adjustments. We found that rotational adjustment has deviations with distinctly different control parameters. We concluded that using a combination of the "full-image" technique and "standard" resolution will be helpful in assisting with patients' repositioning and in correcting for set-up errors prior to radiotherapy on TomoTherapy.

• Progress in Medical Physics
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• v.23 no.4
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• pp.269-278
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• 2012

Aquaplast Thermoplastic (AT) is a tissue-equivalent oral compensator that has been developed to improve dose uniformity at the common boundary and around the treated area during radiotherapy in patients with head and neck cancer. In order to assess the usefulness of AT, the degree of improvement in dose distribution and physical properties were compared to those of oral compensators made using paraffin, alginate, and putty, which are materials conventionally used in dental imprinting. To assess the physical properties, strength evaluations (compression and drop evaluations) and natural deformation evaluations (volume change over time) were performed; a Gafchromic EBT2 film and a glass dosimeter inserted into a developed phantom for dose verification were used to measure the common boundary dose and the beam profile to assess the dose delivery. When the natural deformation of the oral compensators was assessed over a two-month period, alginate exhibited a maximum of 80% change in volume from moisture evaporation, while the remaining tissue-equivalent properties, including those of AT, showed a change in volume that was less than 3%. In a free-fall test at a height of 1.5 m (repeated 5 times as a strength evaluation), paraffin was easily damaged by the impact, but AT exhibited no damage from the fall. In compressive strength testing, AT was not destroyed even at 8 times the force needed for paraffin. In dose verification using a glass dosimeter, the results showed that in a single test, the tissue-equivalent (about 80 Hounsfield Units [HU]) AT delivered about 4.9% lower surface dose in terms of delivery of an output coefficient (monitor unit), which was 4% lower than putty and exhibited a value of about 1,000 HU or higher during a dose delivery of the same formulation. In addition, when the incident direction of the beam was used as a reference, the uniformity of the dose, as assessed from the beam profile at the boundary after passing through the oral compensators, was 11.41, 3.98, and 4.30 for air, AT, and putty, respectively. The AT oral compensator had a higher strength and lower probability of material transformation than the oral compensators conventionally used as a tissue-equivalent material, and a uniform dose distribution was successfully formed at the boundary and surrounding area including the mouth. It was also possible to deliver a uniformly formulated dose and reduce the skin dose delivery.

• Radiation Oncology Journal
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• v.5 no.2
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• pp.97-104
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• 1987

From January 1970 through December 1984, 15 patients with sinonasal Non-Hodgkin's lymphoma combined to the head and neck were treated by external irradiation.13 patients were stage It and 2 were stage IIE by Ann Arbor Classification. However, when using TNM system, 7 were locally advanced T3, T4 lesions. All patients had follow up from 3.7 to 16 years with the median follow-up of 8.5 years. The overall actuarial 5-year survival rates were $25\%,\;28\%$ for IE and $0\%$ for IIE. Total tumor dose varied from 40 to 68 Gy. $100\%$ complete response with a total tumor dose of more than 55 Gy and $73\%$ complete response with less than 55Gy. When the disease was staged using the TNM (AJC) system, the five-year disease free survival for T1 and T2 patients was $50\%$ as compared with $14\%$ for T3 and T4. Failure rate by stage was $33\%(2/6)$ for T1 and T2, $86\%(6/7)$ for T3 and T4, and $100\%$(2/2) for IIE. The results suggest that 1. Higher CR could be obtained with a total tuner dose of more than 55 Gy. 2. Use of TNM staging system is as important as Ann arbor in management of sinonasal NHL. 3. The addition of combination chemotherapy should be considered for T3, T4 and IIE the sinonasal Non-Hodgkin's lymphoma although the disease is limited to head and neck.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.1
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• pp.1-5
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• 2006

Purpose: IMRT quality assurance(Q.A) is consist of the absolute dosimetry using ionization chamber and relative dosimetry using the film. We have in general used 0.015 cc ionization chamber, because small size and measure the point dose. But this ionization chamber is too small to give an accurate measurement value. In this study, we have examined the degree of calculated to measured dose difference in intensity modulated radiotherapy(IMRT) based on the observed/expected ratio using various kinds of ion chambers, which were used for absolute dosimetry. Materials and Methods: we peformed the 6 cases of IMRT sliding-window method for head and neck cases. Radiation was delivered by using a Clinac 21EX unit(Varian, USA) generating a 6 MV x-ray beam, which is equipped with an integrated multileaf collimator. The dose rate for IMRT treatment is set to 300 MU/min. The ion chamber was located 5cm below the surface of phantom giving 100cm as a source-axis distance(SAD). The various types of ion chambers were used including 0.015cc(pin point type 31014, PTW. Germany), 0.125 cc(micro type 31002, PTW, Germany) and 0.6 cc(famer type 30002, PTW, Germany). The measurement point was carefully chosen to be located at low-gradient area. Results: The experimental results show that the average differences between plan value and measured value are ${\pm}0.91%$ for 0.015 cc pin point chamber, ${\pm}0.52%$ for 0.125 cc micro type chamber and ${\pm}0.76%$ for farmer type 0.6cc chamber. The 0.125 cc micro type chamber is appropriate size for dose measure in IMRT. Conclusion: IMRT Q.A is the important procedure. Based on the various types of ion chamber measurements, we have demonstrated that the dose discrepancy between calculated dose distribution and measured dose distribution for IMRT plans is dependent on the size of ion chambers. The reason is small size ionization chamber have the high signal-to-noise ratio and big size ionization chamber is not located accurate measurement point. Therefore our results suggest the 0.125 cc farmer type chamber is appropriate size for dose measure in IMRT.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.257-262
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• 2008

Purpose: Oral mucositis induced by radiotherapy to the head and neck area, is a common acute complication and is considered as the most severe symptom for cancer patients in the early stages of treatment. This study was proposed to establish the oral mucositis mouse model induced by a single dose of radiation for the facility of testing therapeutic candidates which can be used for the oral mucositis treatments. Materials and Methods: Fifty-five BALB/c mice were divided into four groups: control, 16 Gy, 18 Gy, and 20 Gy. Oral mucositis was induced by a single dose of radiation to the head and neck using 6 MV x-Ray from linear accelerator. After irradiation, body weight and physical abnormalities were checked daily. Tongue tissues from all groups were taken on days 1, 2, 3, 5, 7, 9, and 14, respectively and H&E staining was conducted to examine morphological changes. Results: Body weight dramatically decreased after day 5 in all irradiated mice. In the 16 Gy treatment group, body weight was recovered on day 14. The histology data showed that the thickness of the epithelial cell layer was decreased by the accumulated time after radiation treatment, up to day 9. Severe ulceration was revealed on day 9. Conclusion: A single dose of 16 Gy is sufficient dose to induce oral mucositis in Balb/C mice. Significant changes were observed in the Balb/C mice on days 7 and 9 after radiation. It is suggested that this mouse model might be a useful standard tool for studying oral mucositis induced by radiation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.186-195
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• 1994

Fibromatosis is benign fibroblastic proliferative lesion with abundant collagenous neo-formation located principally in the abdominal wall and in the upper and lower extremities (Masson & Soule, 1966). Wilkins and Waldron, in 1975, suggested that the title aggressive fibromatosis was a more appropriate term, reflecting the invasive characteristics of the disease. Synonyms listed were extra-abdominal desmoid, juvenile fibromatosis, aggressive infantile fibromatosis and congenital fibrosarcoma. A total of 12% of all fibromatosis arise in head and neck. Fibromatosis of the oral cavity is uncommon and is even more rare when in involve the mandibule. It is a locally aggressive fibrous tissue tumor, generally does not metastasize, but may cause considerable morbility and even death due to local infiltration. The degree of microscopic cellularity is variable, not only from tumor to tumor but also from area to area in the same tumor. Some tumors present with proliferation of mature fibroblasts and a dominating collagenous component : others may show a lack of the tumor in both types. The common histologic denominator appears to be cellular interlacing bundles of elongated fibroblasts, showing little or no mitotic activity and no pleomorphism. Mitosis are not a consistent index of malignancy when found in younger age groups. Fibromatosis still posses difficult problems of diagnosis and treatment. It is frequently recurrent and infliltrates neighbouring tissues. These lesion infliltrate widely and replace muscle, fat, and even bone with fibrous tissue of varying cellularity. Lesion representing fibromatosis in the oral cavity must be carefully evaulated by both surgeon and pathologists to ensure proper diagnosis and treatment planning. When these lesions involve bone, surgeon must be aware of the lesion's potential to perforate the cortex and expand while remaining hidden from the surgeon's view. Careful and precise clinical correlation with histologic appearance is essential to preclude misdiagnosis of fibrosarcoma yet provide surgical treatment plan that provides adequate local excision and long-term follow up. As regards cause, little is known. It is attributed to trauma or alteration in the sex hormone(Carlos, et al, 1986). Clinially, the lesion is reported to be not painful in most cases, but capable of rapid growth. The treatment is essentially surgical excision with wide margin of adjacent uninvolved tissue. Radiotherapy, hormone treatment or chemotherapy are of no use (WIkins et al, 1975 ; Majumudar and Winiarkl, 1978). We report a case of aggressive fibromatosis of 15-year-old with a lesion in the soft tissue of the parotid area that invaded the underlying bone of the mandibular body.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.488-493
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• 2012

Hemangioma and vascular malformation are the most common benign tumors that are caused by congenitally or traumatic events. Theses tumors represent approximately 1/3~1/4 of all hemangiomas and vascular malformations in the head and neck. There are many forms of treatment for hemangioma and vascular malformation including closed observation, surgery, radiotherapy, laser therapy, steroid therapy, compression, embolization, and sclerotherapy. Ethanolamine oleate is an unsaturated fatty acid salt that has been used as a sclerosing agent because of its excellent thrombosing properties. This paper presents 1 case of intraoral multiple venous malformations treatment with 1.25% ethanolamine oleate (3.6~9.6 mg dose) intralesionally injected for 6 to 14 weeks over 2 week intervals. After the sclerotherapy, lesions almost completely disappeared without side effects. In conclusion, sclerotherapy using ethanolamine oleate is very effective against venous malformations, and sufficiently provides alternative support for surgical and other methods.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.455-461
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• 2000

Malignant tumors of the head and neck frequently require treatment with both radiotherapy and surgery. Reconstruction of the defect in previously irradiated field is a challenge to surgeon, who must produce both a functional and an esthetic result. Hyperbaric oxygen therapy(HBO) has been used in an attempt to reduce the deleterious effects of radiation. But the issue of whether prior irradiation and HBO of the recipient site of a free flap affects the result of reconstruction continues to generate controversy. So, the effects of irradiation and hypergbaric oxygen therapy on microvascular anastomosis was evaluated in an experimental study in femoral vessels of rats. The experimental groups were divided into 3 groups, contorol group, irradiation group, and irradiation and HBO group. Preoperative irradiation was delivered in the left groin field with single dose corresponding 2,000cGy and total 48 hours of HBO was given 100% oxygen at 2.4 atmosphere for 4 weeks. The femoral vessels of 60 rats were anastomosed after irradiation and HBO treatment. Three days, 1 week, 2 weeks and 4 weeks after surgery, the femoral vessels were evaluated for patency and histopathologic changes. There was no notable effect of irradiation on patency of femoral vessels in rats and the radiation effects were obvious on histological examination which showed the sloughing of the endothelial cells, subintimal hyperplasia and fibrosis on the media and adventitia of femoral arteries. The histologic changes of the femoral veins were mild and not typical. But the effects of hyperbaric oxygen therapy after irradiation was seen not marked difference in irradiation group.