Bond strength of composite resin/universal adhesive to dentin submitted to radiotherapy / Fuerza de unión de resina compuesta/adhesivo universal a dentina sometida a radioterapia

Aim: To evaluate the bond strength of a universal adhesive system to dentin submitted to radiotherapy. Materials and Methods: Sixty extracted human teeth were divided into two groups (n = 30): without radiotherapy (control); with radiotherapy, according to the adhesive protocol (n=15): ER-etch-and-rinse (acid + Single Bond Uni-versal); SE-self-etch (Single Bond Universal). The analyzes were shear bond strength (SBS) (n=10), failure pattern (n=10) and scanning electron microscopy (n=5). Data was analyzed by a two-way ANOVA (α =0.05). Results: The radiotherapy decreased SBS of the restorative material to dentin (p<0.0001). The ER protocol provided lower bond strength values (p<0.001). The predominant type of fracture without radiotherapy was mixed (SE), cohesive to the material (ER). Both protocols presented adhesive failures with radiotherapy. Teeth had a hybrid layer and long resin tags (without radiotherapy) and few tags (with radiotherapy). Conclusions: The SE adhesive mode favors the shear bond strength of resin to dentin in teeth submitted to radiotherapy.

Objetivo: Evaluar la fuerza de adhesión de un sistema adhesivo universal a la dentina sometida a radioterapia. Materiales y Métodos: Sesenta dientes humanos extraídos se dividieron en dos grupos (n = 30): sin radioterapia (control); con radioterapia, según protocolo adhesivo (n=15): ER-grabado y enjuague (ácido + Single Bond Universal); autograbado SE (Single Bond Universal). Los análisis ejecutados fueron resistencia al cizallamiento (SBS) (n=10), patrón de falla (n=10) y microscopía electrónica de barrido (n=5). Los datos se sometieron al test de ANOVA de dos vías (α =0,05). Resultados: La radioterapia disminuyó la SBS del material restaurador a la dentina (p<0,0001). El protocolo ER proporcionó valores de fuerza de unión más bajos (p<0,001). El tipo de fractura predominante sin radioterapia fue mixta (SE), cohesiva al material (ER). Ambos protocolos presentaron fallas adhesivas con radioterapia. Los dientes tenían una capa híbrida y colas de resina largas (sin radioterapia) o pocas colas de resina (con radioterapia). Conclusión: El modo adhesivo SE favorece la resistencia al corte de la resina a la dentina en dientes sometidos a radioterapia.

Research progress of 125I radioactive seed interstitial brachytherapy in the treatment for pelvic malignancies / 中华放射医学与防护杂志

Brachytherapy with 125I radioactive seed has the advantages of low dose-rate,comtinuous irradiation and repeated implantation to inhibit the replication of tumor cells,and the repeatable implantation.It has been widely used in the treatment for cervial cancer,and can also be applied to pelvic malignancies,including ovarian cancer,colorectal cancer,bladder cancer.Compared with external beam radiotherapy,it can improve the dose of target region to control tumor effectively.At the same time,it can protect the normal tissues and reduce the occurrence of complications.In this paper,we summarized the speciahy,function mechanism,complications and application status of radioactive 125I seed interstitial implantation in the treatment of pelvic malignancies.The application of three dimensional printing in brachytherapy with radioactive 125I seed was also introduced.This review can provide a reliable basis for future standardized seed implantation treatment for pelvic malignancies.

Reacciones adversas al tratamiento radiante en el adulto mayor con cáncer / Adverse reactions to the radiation treatment in the elderly with cancer

Se realizó un estudio descriptivo y transversal para caracterizar clínicamente a 707 pacientes con cáncer, tratados en el Hospital Oncológico Provincial Docente "Conrado Benítez García" de Santiago de Cuba, durante el año 2013, por presentar reacciones adversas secundarias a la radioterapia. En la casuística, 484 afectados presentaron toxicidad (68,4 %). Predominaron el sexo masculino, el grupo etario de 60-70 años, los tumores de próstata y mama, así como el estadio clínico II. Entre las reacciones adversas más frecuentes sobresalieron: radiodermitis, rectitis y anemia. La hipertensión, las cardiopatías y las enfermedades cerebrovasculares se asociaron al tumor. Hubo más reacciones adversas cuando se usó la radioterapia concurrente con la quimioterapia, y la remisión completa se logró en los pacientes que no interrumpieron el tratamiento.

A descriptive and cross-sectional study to characterize clinically 707 patients with cancer, treated in "Conrado Benítez García" Teaching Provincial Oncological Hospital from Santiago de Cuba was carried out during the year 2013, for presenting secondary adverse reactions to the radiotherapy. Toxicity (68.4%) was present in 484 affected patients from the case material. The male sex, the age group 60-70 years, the prostate and breast tumors, as well as the clinical stage II prevailed. Among the most frequent adverse reactions there were: radiodermitis, rectitis and anemia. Hypertension, cardiopathies and cerebrovascular diseases were associated to the tumor. There were more adverse reactions when the concurrent radiotherapy was used with chemotherapy, and the complete remission was achieved in the patients who didn't interrupt the treatment.

Analysis and evaluation on performance detection of radiation treatment equipment / 中国医学装备

Objective:To evaluate the clinical performance of radiation treatment equipment inspection status of the medical and health institutions in Nanjing. Methods: Twenty-two 60Coy teletherapy machine and 12 Teclast subsidiary medical accelerator were detacted from January 2012 to December 2012 in Nanjing. Results: The performance qualified rate of 60Coy teletherapy machine is higher. In other standards, the 60Coy teletherapy machines have different degrees of failures. The performance test results of electronic medical accelerator is good, the majority of medical electronic accelerator performance can comply with the relevant national standards. Conclusion: Regular checks on the performance of radiation treatment equipment and on time check can ensure clinical efficacy and safety of patients treated with radiotherapy treatment.

Influence of Couch and Collimator on Dose Distribution of RapidArc Treatment Planning for Prostate Cancer in Radiation Therapy / 의학물리

We investigated the influence of photon energy, couch and collimator angle differences between arcs on dose distribution of RapidArc treatment planning for prostate cancer. RapidArc plans were created for 6 MV and 10 MV photons using 2 arcs coplanar and noncoplanar fields. The collimator angle differences between two arcs were 0degrees, 15degrees, 30degrees, 45degrees, 60degrees, 75degrees and 90degrees. The plans were optimized using same dose constrains for target and OAR (organ at risk). To evaluate the dose distribution, plans were analyzed using CI (conformity index), HI (homogeneity index), QOC (quality of coverage), etc. Photon energy, couch and collimator angle differences between arcs had a little influence on the target and OAR. The difference of dosimetric indices was less than 3.6% in the target and OAR. However, there was significant increase in the region exposed to low dose. The increase of V15% in the femur was 6.4% (left) and 5.5% (right) for the 6 MV treatment plan and 23.4% (left), 24.1% (right) for the noncoplanar plan. The increase of V10% in the Far Region distant from target was 54.2 cc for the 6 MV photon energy, 343.4 cc for the noncoplanar and 457.8 cc for the no collimator rotation between arcs.

The clinical application of intra-radiation stenting for the treatment of esophageal carcinoma / 介入放射学杂志

Objective To discuss the feasibility and curative effect of intra-radiation stenting(125Iparticle stent)for the treatment of advanced esophageal cancers.Methods Fifteen patients with advanced esophageal cancer were enrolled in this study.Under X-ray guidance the esophageal stent,which was tied up with 125I radioactive particles,was orally inserted to the diseased region of the esophagus.The clinical manifestations and imaging findings were observed and the results were analyzed.Results After the operation all the clinical symptoms such as dysphasia showed an obvious improvement.No serious complications such as infection,hemorrhage,radiation pneumonia,etc.Occurred.The re-examination at 3-6 months after the treatment showed that the tumor size Was decreased in a certain degree in 14 patients,and in the remaining one patient the lesion became bigger and grew to the upper opening of the stent,resulting in esophageal restenosis.Conclusion The intra-esophageal implantation of radioactive stent is a feasible and safe treatment for the advanced esophageal cancers with excellent curative results.

Comparison of Three- and Four-dimensional Robotic Radiotherapy Treatment Plans for Lung Cancers / 대한방사선종양학회지

PURPOSE: To compare the dose distributions between three-dimensional (3D) and four-dimensional (4D) radiation treatment plans calculated by Ray-tracing or the Monte Carlo algorithm, and to highlight the difference of dose calculation between two algorithms for lung heterogeneity correction in lung cancers. MATERIALS AND METHODS: Prospectively gated 4D CTs in seven patients were obtained with a Brilliance CT64-Channel scanner along with a respiratory bellows gating device. After 4D treatment planning with the Ray Tracing algorithm in Multiplan 3.5.1, a CyberKnife stereotactic radiotherapy planning system, 3D Ray Tracing, 3D and 4D Monte Carlo dose calculations were performed under the same beam conditions (same number, directions, monitor units of beams). The 3D plan was performed in a primary CT image setting corresponding to middle phase expiration (50%). Relative dose coverage, D95 of gross tumor volume and planning target volume, maximum doses of tumor, and the spinal cord were compared for each plan, taking into consideration the tumor location. RESULTS: According to the Monte Carlo calculations, mean tumor volume coverage of the 4D plans was 4.4% higher than the 3D plans when tumors were located in the lower lobes of the lung, but were 4.6% lower when tumors were located in the upper lobes of the lung. Similarly, the D95 of 4D plans was 4.8% higher than 3D plans when tumors were located in the lower lobes of lung, but was 1.7% lower when tumors were located in the upper lobes of lung. This tendency was also observed at the maximum dose of the spinal cord. Lastly, a 30% reduction in the PTV volume coverage was observed for the Monte Carlo calculation compared with the Ray-tracing calculation. CONCLUSION: 3D and 4D robotic radiotherapy treatment plans for lung cancers were compared according to a dosimetric viewpoint for a tumor and the spinal cord. The difference of tumor dose distributions between 3D and 4D treatment plans was only significant when large tumor movement and deformation was suspected. Therefore, 4D treatment planning is only necessary for large tumor motion and deformation. However, a Monte Carlo calculation is always necessary, independent of tumor motion in the lung.

Effect of High Protein Diet and Resveratrol Supplementation on the Nutritional Status and Immunoreactivity in the Irradiation-induced Inflammatory Rats

Most cancer patients are treated with surgery, chemotherapy or radiation as anticancer therapies. Especially in the case of radiation, these treatments produce adverse effects such as vomiting, weight loss, anorexia, normal cell damage and malabsorption. The major goal of this study was to determine the effect of irradiation on the nutritional and immune status in irradiated rats. A secondary goal was to determine the effectiveness of high protein diet (HP) and resveratrol (Res) in minimizing the adverse effects of radiation. Rats were divided into four groups: normal diet (NP), HP, NP + Res and HP + Res groups. Each group was further divided into subgroups that received radiation (RT group) and one that did not (non-RT group). Each diet was supplied from 12th day prior to irradiation treatment with irradiation dose of 17.5 Gy. The diets were continued until 10th day after radiation treatment and animals were sacrificed. The radiation treatment showed decreased body weight, serum protein and HDL levels and increased TG and LDL levels in nutritional status. HP, NP + Res and HP + Res groups reduced the level of serum LDL and TG in irradiated rats. NP + Res and HP + Res groups increased reduced albumin level of serum in RT group. In case of immune status, the radiation treat-ment showed decreased WBC, lymphocytes and increased neutrophil and eosinophil levels. The levels of serum IL-2 and IL-6 were significantly increased by radiation, however the cytokine levels decreased in all dietary treatment groups. These results showed that high protein diet and resveratrol supplementation seem to minimize the adverse effects of radiation on lipid nutritional status and inflammation response in the rat model.

A Comprehensive Computer Program for Monitor Unit Calculation and Beam Data Management: Independent Verification of Radiation Treatment Planning Systems / 의학물리

We developed a user-friendly program to independently verify monitor units (MUs) calculated by radiation treatment planning systems (RTPS), as well as to manage beam database in clinic. The off-axis factor, beam hardening effect, inhomogeneity correction, and the different depth correction were incorporated into the program algorithm to improve the accuracy in calculated MUs. A beam database in the program was supposed to use measured data from routine quality assurance (QA) processes for timely update. To enhance user's convenience, a graphic user interface (GUI) was developed by using Visual Basic for Application. In order to evaluate the accuracy of the program for various treatment conditions, the MU comparisons were made for 213 cases of phantom and for 108 cases of 17 patients treated by 3D conformal radiation therapy. The MUs calculated by the program and calculated by the RTPS showed a fair agreement within +/-3% for the phantom and +/-5% for the patient, except for the cases of extreme inhomogeneity. By using Visual Basic for Application and Microsoft Excel worksheet interface, the program can automatically generate beam data book for clinical reference and the comparison template for the beam data management. The program developed in this study can be used to verify the accuracy of RTPS for various treatment conditions and thus can be used as a tool of routine RTPS QA, as well as independent MU checks. In addition, its beam database management interface can update beam data periodically and thus can be used to monitor multiple beam databases efficiently.

Development of QA Phantom Prototype for Imaged Based Radiation Treatment System / 의학물리

In this study, we developed the protopype of QA phantom for image QA including an additional component for image based radiation treatment system. The new phantom considered two main parts: Image quality and fusion accuracy. Image quality part included for daily CT number linearity and spatial resolution, and fusion accuracy part designed to simulate a simple translation-rotation setting. The CT scans of the phantom obtained from conventional CT, MVCT of Tomotherapy unit, and both image sets were satisfied the recommendation of spatial resolution. This phantom was simple and efficient for daily imaging QA, and it is important to provide a new concept of verification of image registration.

Clinical Characteristics of Inflammtory Pseudotumor of the Orbit / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Inflammatory pseudotumor is not malignant, but similar to malignancy lesions with respect to its clinical and radiological manifestations. It is well-known to opthalmologists and neurosurgeons, but unfamiliar to otolaryngologists. The objective of this study is to determine the diagnosis and treatment of inflammatory pseudotumor of the orbit. SUBJECTS AND METHOD: We reviewed 17 patients who visited Kangnam St. Mary's hospital and were diagnosed with inflammatory pseudotumor with clinical manifestations and radiological studies between September, 1994 and December, 2006. RESULTS: Seventeen patients were treated with high dose steroid, and of these, 12 showed clinical improvement, although 7 of these patients later showed recurrence. Of the five patients who initially showed no clinical improvement, one received radiation therapy but did not show improvement whereas two patients showed no improvement. One patient's symptoms improved after surgical decompression. CONCLUSION: Our study suggests that the initial treatment of inflammatory pseudotumor should be high dose steroid treatment without improvement and the second treatment should be radiation therapy or surgical treatment.

Quality Assurance in Intensity Modulated Radiation Theray / 영남의대학술지

Intensity-modulated radiation therapy (IMRT) is believed to be one of the best radiation treatment techniques. IMRT is able to deliver fatal doses of radiation to the tumor region with minimal exposure of critical organs. It is essential to have a comprehensive quality assurance program to assure precision and accuracy in treatment, due to the character of IMRT. We applied quality assurance technique to the Eclipse treatment planning system and sought to determine its effectiveness in patient treatment planning. An acrylic phantom, film, and an ionization chamber were used in this study.

Novalis Shaped Beam Radiation Treatment for Craniopharyngiomas

OBJECTIVE: To evaluate the effectiveness of Novalis shaped beam radiation treatment as an adjuvant treatment in patients with craniopharyngiomas. METHODS: We reviewed 8 patients with craniopharyngiomas who had recurring tumors during follow-up or had residual lesions after primary surgery. Three of 8 patients were found to have recurrence after gross total excision of the tumor and 5 patents had residual lesions after subtotal resection. All patients were treated with fractionated stereotactic radiation treatment(FSRT) using Novalis system. The mean age of patients was 28 years (range 16~52). The median irradiation dose per fraction was 1.7Gy (range 1.7~2.0). The median fraction number was 23 (range 15~25), and the median total dose was 39.1Gy (range 25.5~42.5). Follow-up included MR imaging, and ophthalmologic and endocrine examinations. RESULTS: The median follow-up period was 23 months (range 12~43). The local tumor control rate was 87.5%. One patient had a recurring tumor, in which cystic change developed 2 months after FSRT. Four patients showed a decrease in size of their tumor, while 3 patients remained stable. Seven out of 8 patients had hormonal dysfunction that remained unchanged after initial surgery. No further progression of visual impairment was observed. CONCLUSION: FSRT using Novais system is effective and safe for the treatment of recurring or residual craniopharyngiomas without toxicity like optic neuropathy.

Determination of Tumor Volume in PET for the Radiation Treatment Planning : Computer Simulation / 의학물리

The utilization of PET has been increased so fast since the usefulness of the PET has been proved in various clinical and research fields. Among the many applications, the PET is especially useful in oncology and most of the clinical PET scans are performed for the oncologic examination including the different diagnosis of malignant and benign tumors and assessment of the treatment effects and recurrent tumors. As the PET-CT scanners are widely available, there is increasing interest in the application of the PET images to the radiation treatment planning. Although the CT images are conventionally used for the target volume determination in the radiation treatment planning, there are fundamental limitation in use of only the anatomical information. Therefore, the volume determination of the functionally active tumor region using the PET would be important for the treatment planning. However, the accurate determination of the tumor boundary is not simple in PET due to the relatively low spatial resolution of the currently available PET scanners. In this study, computer simulations were performed to study the relationship between the lesion size, PET resolution, lesion to background ratio and the threshold of image intensity to determine the true tumor volume.

Evaluation of Tumor Registry Validity in Samsung Medical Center Radiation Oncology Department / 대한방사선종양학회지

PURPOSE: A tumor registry system for the patients treated by radiotherapy at Samsung Medical Center since the opening of a hospital at 1994 was employed. In this study, the tumor registry system was introduced and the validity of the tumor registration was analyzed. MATERIALS AND METHODS: The tumor registry system was composed of three parts: patient demographic, diagnostic, and treatment information. All data were input in a screen using a mouse only. Among the 10,000 registered cases in the tumor registry system until Aug, 2002, 199 were randomly selected and their registration data were compared with the patients' medical records. RESULTS: Total input errors were detected in 15 cases (7.5%). There were 8 error items in the part relating to diagnostic information: tumor site 3, pathology 2, AJCC staging 2 and performance status 1. In the part relating to treatment information there were 9 mistaken items: combination treatment 4, the date of initial treatment 3 and radiation completeness 2. According to the assignment doctor, the error ratio was consequently variable. The doctors who did no double-checks showed higher errors than those that did (15.6% : 3.7%). CONCLUSIONS: Our tumor registry had errors within 2% for each item. Although the overall data quality was high, further improvement might be achieved through promoting sincerity, continuing training, periodic validity tests and keeping double-checks. Also, some items associated with the hospital information system will be input automatically in the next step.

Optimal Radiation Therapy Field for Malignant Astrocytoma and Glioblastoma Multiforme / 대한방사선종양학회지

PURPOSE: This study was performed to determine the optimal radiation therapy field for the treatment of malignant astrocytoma and glioblastoma multiforme. MATERIALS AND METHODS: From Jan. 1994 to Mar. 2000, 21 patients with malignant astrocytoma and glioblastoma multiforme, confirmed as recurrent by follow up MRI after surgery and radiation therapy, were analyzed. The distance from the margin of the primary lesion to the recurrent lesion was measured. The following factors were analyzed to investigate the influence of these factors to recurrence pattern; tumor size, degree of edema, surgical extent, gamma knife radiosurgery and multiple lesions. RESULTS: Among the 21 patients, 18 (86%) were recurred within 2 cm from the primary lesion site. 12 within 1 cm, 6 between 1 and 2 cm. The other 3 patients all with multiple lesions, were recurred at 3, 4, 5 cm, from the primary lesion site. The recurrence pattern was not influenced by the factors of tumor size, extent of edema, surgical extent, or gamma knife radiosurgery. However, patients with multiple lesions showed a tendency of recurrence at sites further from the primary lesion. CONCLUSIONS: Most (86%) of the recurrences of malignant astrocytoma and glioblastoma multiforme occurred within 2 cm from the primary lesion site. The width of treatment field does not need to be changed according to tumor size, degree of edema, surgical extent, or gamma knife radiosurgery. However, the treatment field for multiple lesions appears to be wider than that for a single lesion.

Postoperative Adjuvant Chemotherapy and Radiotherapy for Stage II and III Non-Small Cell Lung Cancer (NSCLC)

PURPOSE: The role of postoperative adjuvant chemo-radiotherapy in the treatment of patients with non-small cell lung cancer (NSCLC) remains unclear. This study was undertaken to evaluate the survival outcomes, relapse patterns, prognostic factors and complications of postoperative adjuvant MVP chemotherapy and radiotherapy. MATERIALS AND METHODS: The study involved some 96 patients who had undergone curative resection of stage II and III NSCLC between 1991 and 1996. Among these, 94 patients who completed their adjuvant treatment were analyzed. Surgery consisted of pneumonectomy (33%), single lobectomy (54%) or bilobectomy (13%). Within 4 weeks of curative resection, two cycles of MVP chemotherapy (mitomycin C 8 mg/m2, vinblastine 8 mg/m2, cisplatin 60 mg/m2) were started at 4 weeks intervals. Conventionally fractionated radiotherapy was given 3 weeks after chemotherapy to a total dose of 50 Gy in completely resected patients and 55~60 Gy in patients with positive resection margins. RESULTS: The TNM classification of the AJCC, as revised in 1997, was used for pathologic staging. The number of patients at AJCC stages IIa, IIb, IIIa, and IIIb were 4, 40, 45, and 5, respectively. A pathologically positive bronchial resection margin was found in nine patients. At the time of analysis, death was recorded in 29 patients (31%), though five had died without evidence of lung cancer. Overall 2-year, 3-year, and 5-year survival rates for all patients were 74.2%, 70.2%, and 65%, respectively, locoregional diseasefree survival (LRDFS) rates were 88.6%, 83.7%, 74.3%, at 2-years, 3-years, and 5-years, and distant metastasis disease-free survival (DMDFS) rates were 67.7%, 65.0%, and 63.6%, respectively. In the multivariate model, a primary tumor size of more than 5 cm and the level of pathologically positive nodes were found to be associated with poor overall survival, LRDFS and DMDFS. Although positive bronchial resection margin affected overall survival, LRDFS and DMDFS were unaffected. With respect to the first site of relapse, distant metastasis occurred more frequently (N=33, 35%) than locoregional recurrence (N=15, 16%). Grade 3 esophagitis in two patients and weight loss of more than 10% in five patients were observed during adjuvant treatment. Grade 4 pulmonary toxicity was observed in one patient after radiotherapy and this patient ultimately died 5 months after treatment. CONCLUSION: The postoperative adjuvant MVP chemotherapy and radiotherapy regimen showed relatively low locoregional recurrence and distant metastasis rates and good survival rate with acceptable toxicity. A prospective randomized trial, which compares this regimen to surgery alone or postoperative adjuvant radiotherapy is needed.

Reduction of postradiation xerostomia in patients with head and neck cancer by superior technology using 3D-RTPS / 实用口腔医学杂志

Objective: To observe the effect of superior technology using three dimension radiation treatment plans (3D-RTPS) in the reduction of postradiation xerostomia in patients with head and neck cancer. Methods: 3D-RTPS of conventional radiation and new superior technique were applied in the patients of 3 kinds of head and neck cancer (tumor in middle, lateral, between middle and lateral area of head and neck). Superior technology including superior ray entrance, multi fields, conformal irradiation and application of wedges. Analysis of 3D dose distributions and dose volume histograms (DVH) was used to evaluate the dose and volume in tumor, parotids and spinal cord in the patients. Tumor dose of 55.6～68.6 Gy (average 58.8 Gy) was given to the patients in conventional radiation group in 8 patients, 53.5～68.5 Gy (average 58.3 Gy) to new radiation technique group in 12 patients. Whole saliva flow rate and subjective xerostomia scores were assessed in patients during radiation course and follow-up. Results: The dose in contralateral parotids in patients with tumor in lateral area, between lateral and middle area in conventional radiation and new radiation technique groups were 51.8～64.3 Gy and 0.4～1.4 Gy, respectively. The dose in parotids in patients with tumor in middle area in conventional radiation and new radiation technique groups were 51.8 and 24.7 Gy respectively. The rate of xerostomia at the end of radiotherapy and in 4～6 months follow-up after radiotherapy in patients of new radiation technique group were 8.3 % (1/12) and 0 respectively. Those in patients in conventional radiation group were 87.5 % (7/8) and 50 % (4/8) respectively. Conclusion: Superior technology using 3D-RTPS can reduce the rate of postradiation xerostomia in patients with head and neck cancer.

Measurements of Setup Error and Physiological Movement of Liver by Using Electronic Portal Imaging Device in Patients with Hepatocellular Carcinoma / 대한방사선종양학회지

PURPOSE: The goal of this study was to improve the accuracy of three-dimensional conformal radio therapy (3-D CRT) by measuring the treatment setup error and physiological movement of liver based on the analysis of images which were obtained by electronic portal imaging device (EPID). MATERIALS AND METHODS: For 10 patients with hepatocellular carcinoma, 4-7 portal images were obtained by using EPID during the radiotherapy from each patient daily. We analyzed the setup error and physiological movement of liver based on the verification data. We also determined the safety margin of the tumor in 3-D CRT through the analysis of physiological movement. RESULTS: The setup errors were measured as 3 mm with standard deviation 1.70 mm in x direction and 3.7 mm with standard deviation 1.88 mm in y direction respectively. Hence, deviation were smaller than 5 mm from the center of each axis. The measured range of liver movement due to the physiological motion was 8.63 mm on the average. Considering the motion of liver and setup error, the safety margin of tumor was at least 15 mm. CONCLUSION: EPID is a very useful device for the determination of the optimal margin of the tumor, and thus enhance the accuracy and stability of the 3-D CRT in patients with hepatocellular carcinoma.

Radiotherapy for Age-related Macular Degeneration Associated with Subfoveal Neovascular Membrane

The only effective treatment for subfoveal neovascular membrane in age-related macular degeneration is laser photocoagulation, which is associated with decreased visual acuity following treatment in most patients. Radiation treatment for subfoveal neovascular membrane has been tried, but its effectiveness and necessary dose are not determined yet. Twelve eyes with subfoveal neovascular membranes received X-ray radiation with the dose of 1980cGy or 1440cGy. After a minimum 6 month follow-up, 4 eyes had improved, 6 eyes had stable and 2 eyes had worsened visual acuity. To date no negative side effects have been observed. We could not find difference in visual outcome between two dose groups due to the small sample size. Regarding the poor natural course of age-related macular degeneration, these results suggest a possible beneficial effect of radiation treatment with total dose of 1980 or 1440cGy and justify the further treatments and evaluations of the radiotherapy.