Single modality therapy for esophageal cancer usually consists of surgery or radiotherapy, and surgery has been considered the treatment of choice for operable patients with locoregionally confined lesions. However, recent analyses of survival rates reported for the two modalities suggest that each offers a 5-year survival of approximately 6%. In addition, advances in the use of chemoradiotherapy for esophageal cancer indicate several potential advantages of chemoradiotherapy over surgical resection. A number of phase II sudies of concurrent chemoradiotherapy demonstrated encouraging results. Several phase III studies comparing radiotherapy alone to chemoradiotherapy clearly indicate the survival of concurrentchemoradiotherapy to be better than radiotherapy alone. Prospective randomized trials comparing surgical resection and concurrent chemoradiotherapy are required

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Patterns of Care Study (PCS) was originally developed in the United States for the clinical quality assurance in radiation oncology. PCS consists of three surveys on structure, process and outcome. Process survey uses two-stage cluster sampling by stratification of institutions and the patients in sampled institution. Statistical national average on each survey item by Sedransk's formula is calculated using these parameters. This national average is a benchmark of clinical quality assurance of radiation oncology for national practice as well as each institution. PCS in the United States has shown enormous evidence that even elementary radiotherapy technique has improved the nationwide outcomes for various cancer patients during the past 25 years. PCS will be feasible in Japan.

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OBJECTIVE: Intracavitary brachytherapy occasionally causes bowel injuries other than rectum. To relieve these adverse events, we investigated the relationships between uterine bodies and surrounding bowels using MRI.
MATERIALS AND METHODS: A hundred and ten of serial 252 pelvic MRI of women, excluding the following, were reviewed. The excluded items were (1) large intrapelvic extrauterine masses over 3.5 cm in greater diameter, (2) large uterine corpus masses over 2 cm, (3) three or more uterine corpus masses, (4) past history of hysterectomy or rectocolonic resection, (5) massive ascites. We investigated the fundus-bowel distance (FBD), site of the nearest bowel to the uterine body, flexion type and deviation of uterus, uterine wall thickness, subcutaneous fat thickness and age.
RESULTS: FBD ranged from 8 to 42 mm (20.2 ± 8.2mm). In 66 cases (60%), FBD was 20mm or less. The sites of the nearest bowel were 67 sigmoid colons, 27 rectums, 8 small intestines, and 7 descending colons. Eighty-three uteri (75.5%) were anteflexion and 27 uteri (24.5%) were retroflexion. Of the anteflexion group, 78.3% were adjacent to the sigmoid colon, and 92.6% of the retroflexion group were adjacent to rectum. Right-deviation uteri represented 33 cases (30%); mid-position 33, (30%); and left-deviation uteri, 44 (40%). Uterine wall thickness was 5 to 33mm (17.8 ± 5.2). Subcutaneous fat thickness was 10 to 47 mm (20.2 ± 9.3). The age of patients ranged from 21 to 83 years (39.9 ± 14.4). FBD showed statistical good correlation to uterine wall thickness and subcutaneous fat thickness. In anteflexion group, correlation of uterine wall thickness with FBD was significant. In retroflexion group, however, it was not significant. The site of bowels, flexion type, and deviation type did not correlate with FBD. FBD, uterine wall thickness and subcutaneous fat thickness showed regression of quadric curves with age; these peaked at ages 50.4, 46.0 and 46.2, respectively.
CONCLUSION: It is presumed that predictive factors of bowel complication are thin uterine wall, young and aged, thin patients and retroflexion uterus. Uterine deviation does not shorten FBD. To relieve a radiation injury to bowels adjacent to the uterine fundus, the isodose curve must be decrease the irradiation dose of the tandem tip. At this time we conformed so as to recommend refering to MRI, CT and ultrasonography to detect the uterine wall thickness and the involved area of primary carcinoma. Retroflexion uterus as should be reformed to anteflexion by hard tandem applicator. Laterally-deviated uteruses should be adjusted such that they lie within the central shielding zone of the external beam.

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Total body irradiation (TBI) has proven to be a major tool in the treatment of childhood leukaemia followed by bone marrow transplantation (BMT). However, growth impairment and growth hormone (GH) deficiency have been reported in children treated for leukaemia. We have studied growth, GH secretion and bone age in long term survivors of the children who treated with TBI+BMT or whole brain radiation therapy (WBRT) +TBI+BMT. TBI was delivered by 4 MV X-ray linear accelerator for a total dose of 1000-1200 cGy for 4 days. WBRT was delivered by 10 MV X-ray linear accelerator for a total dose of 1500-2400 cGy for 2-4 weeks. The body surface dose was measured with pairs of TLD and pairs of semiconductor detectors. In case of TBI, the average dose to each site was 1045 cGy for the head and 1089 for the knee. The maximum dose to the head in case of WBRT+TBI was 2390 cGy. Growth impairment was recognized in 5 of 10 patients treated with TBI and in 2 of 2 patients treated with WBRT+TBI. We observed most of growth impairment and GH deficiency during the first 3 years. Radiation dose may be an important factor for the problems in growth impairment but other factor: chronic graft-versus-host-disease and its treatment affects growth treated for leukaemia.

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In order to achieve maximal radiation dose concentration for thoraco-abdominal tumors and spare normal surrounding tissue in heavy ion therapy, compensation for respirationrelated movement is desirable. Hence, a respiration-gated irradiation system (ReGIS) was introduced to the Heavy lon Medical Accelerator in Chiba (HIMAC) in June 1996. In this report, the development and clinical application of ReGIS, as well as the analysis of respiration-related movement and reduction of target volumes are described. When using ReGIS, a sensor emitting infrared rays is attached to the thoracic or abdominal wall to measure respiratory movement. A position-sensitive device (camera) senses these rays to detect sensor locations and data are forwarded to a computer system. A curve representing respiratory cycles is displayed, upon which a trigger level that is part of a respiratory cycle (about a fourth or fifth of the expiratory phase). Beams can be delivered while the respiratory curve is under the trigger level. Thirtyfive patients involving 37 irradiated sites (19 lung cancers, 13 hepatomas, 2 mediastinal tumors, and 3 metastatic lung tumors) were retrospectively analyzed. Target volumes were reduced an average of 29.5%(11.0 to 57.9%) using ReGIS. Average tumor respiration-related movement in gated phase was 3.7mm (0mm to 14.6mm). Although irradiation using ReGIS took more time to perform (average 1.62 times non-gated irradiation), it was considered to be acceptable for routine heavy ion therapy. ReGIS has proved to be useful for compensation of respirationrelated movement and reduction of target volume in radiotherapy, and this method is sufficiently simple for practical clinical application.

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Stereotactic irradiation using a linear accelerator has been widely adopted in many hospitals recently. For this radiotherapy technique, accurate dosimetry is important for defining the position and dimensions of the irradiation field, and determining the absorbed dose to target volume.
Nevertheless, there are some uncertainties caused by a smaller field than conventional techniques. A major cause for the uncertainties is a variation in the photon and electron energy spectrum depends on field size and depth.
In this study, the energy spectra of photons and electrons in water were calculated using a Monte Carlo simulation. It was evident that photon and electron energy spectra changed as a function of field size and depth in water. To estimate the influence of the variation in energy spectrum on an ionization chamber, the ratios of the mean restricted mass collision stopping power of water to air were determined using the electron energy spectra. It was evident that uncertainty of the stopping power ratio caused by a variation in field size and depth was less than 1% for an energy range below 10 MV. Nevertheless, the uncertainty exceeded 1% at points deeper than 15cm for fields smaller than 1cm in diameter of 15 and 24 MV.

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Long-term cosmetic outcomes and complications were evaluated in 109 patients with breast cancer who had been treated by breast conservation therapy. Patients received radiation therapy at Kyoto University Hospital following quadrantectomy and level II or III axillary node dissection. Factors that might influence long-term cosmetic results were also analyzed. Irradiation to the breast was administered in 2 Gy fractions, 5 times a week for a total of 50 Gy in all patients. Cobalt-60 γA-rays were used in 108 patients with the exception of 1 patient who received 6 MeV X-ray. Some patients with positive or close margins received boost irradiation of 10 Gy using electron beams to the primary tumor bed. Cosmetic outcome was assessed by both a scoring method and breast retraction assessment (BRA). Forty-seven percent of patients were assessed as excellent to good before radiation therapy. The percent of excellent to good decreased shortly after termination of radiation therapy, but gradually improved and stabilized by 3 years. Seventy percent of patients showed a score of excellent to good 5 years after treatment. The average BRA of the 109 patients was 3.0 cm. This did not change between 3 and 5 years after treatment. A significant correlation between cosmetic score and BRA was shown at all follow-up times. Factors such as age over 50 years (p=0.008), tumor location in the outer quadrant (p=0.02) and boost irradiation (p=0.03) significantly affected the cosmetic score. Arm edema and restriction of shoulder movement were observed in 22% and 49% at the start of radiation therapy, these improved within approximately 3 years and 1 year after treatment, respectively. Mild skin change was observed in 60% of patients even 5 years after treatment. The results indicate that cosmetic outcome after breast conservation therapy is clinically acceptable, and the complication rate is low.

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A 38-years-old man presented with right cheek pain and swelling. CT revealed an irregular shaped right maxillary mass, with both cystic and solid components and destruction of anterior bony wall. Enucleation of the mass was performed. Histologic examination revealed odontogenic ghost cell carcinoma. A recurrent tumor was seen at 2 months after enuculeation, and the patient underwent a partial maxillectomy and 54Gy of postoperative radiotherapy. No sign of local recurrence or distant metastasis was observed at the 19 months follow-up.

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Two cases of malignant lymphoma of the larynx are presented. Case 1 is a 67-year-old female in clinical stage IIEA. Irradiation of 42 Gy was given to the bilateral neck and supraclavicular area. The patient has been disease-free for nearly 15 years after irradiation. Case 2 is an 86-year-old female in clinical stage IEA. Irradiation of 45.2 Gy was delivered to the larynx. The patient had been disease-free for 7.5 years up to her death from intercurrent disease. Histologically, these tumors belonged to the category of low grade B-cell lymphoma of mucosaassociated lymphoid tissue (MALT-type). Although chemotherapy was administered in these 2 cases, it did not lead to an effective outcome. In conclusion, radiotherapy can be considered as a definitive treatment modality for primary malignant lymphoma of the larynx.

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In many Japanese institutions, patient conveyance from operation room to radiation therapy department is performed while the patients is under general anesthesia. Only few institutions have an operation room inside of the radiation therapy department. This situation prevents smoothly performance of IORT. To help remedy this situation we developed a new Intraoperative radiation therapy system using the Microtron beam transport (Hitachi Medico Co Ltd).
This new IORT system consists of two Microtron gantries (HTM 2202); the generator and first gantry is located on the B1 floor and uses conventional external beam radiotherapy (Photon and electron). The second gantry is located on the operation room floor (2nd floor) and an electron beam is introduced using a beam transport system that is used only by IORT. Electron beam energy selection of 3, 5, 7, 9, 11, 13, 16, 18, 20 and 22 Mev are provided. This system also provides a color video monitoring system within the treatment cone for easy and accurate setting of the radiation field. This new IORT system, developed at our hospital may contribute to the development and wide spread use of IORT.

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