The mortality rate for cervical cancer has been steadily decreasing due to widespread cytologic screening. However, increasing incidence of early stage cervical cancer and its precursor has been reported in young patients who need to preserve uterine function. Various modalities for conservative treatment which fit to the patient's need have been developed.
In Japan, patients with stages Ib-IIb are treated surgically and patients with stages III-IV are treated with irradiation. However, the data show that there has been no improvement of 5-year survival rate by each stage. It became apparent that the larger the tumor size, the worse the prognosis. Accordingly, FIGO changed its definition of stage I cervical cancer in 1994. Stage Ib2 patients with tumor diameter more than 4 cm have poorer survival than patients with a smaller tumor. These patients need more aggressive therapy than surgery only.
We have accomplished some for the treatment of early cervical cancer, but not enough for advanced cancer. Several trials, such as neoadjuvant chemotherapy, interstitial radiation, and cytoreductive surgery, are being performed aggressively, but we still have to wait for the results. Gynecologic oncologists, radiation oncologists, and medical oncologists have to work together to treat advanced cervical cancer.

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An electronic portal imaging device (EPID) has been applied for clinical use at Kyoto University Hospital since 1993. The EPID is a liquid-filled ionization chamber system (Portal Vision, Varian Associates). Portal images of 104 treatment fields from 93 patients were taken using a treatment beam and were verified with simulation images. The range of setup deviation was almost within 5 mm for head and neck, and pelvic fields, while within 10 mm for thoracic fields. In both a transverse direction and a longitudinal direction, the mean setup deviation was larger in thoracic fields than in head and neck, and pelvic fields. There are still some problems to be solved with this EPID system. The time taken for image acquisition is more than 6.5 seconds and the image quality is not satisfactory for accurate verification. However, the real time monitoring of patients' position during treatment which enables quick detection of major setup errors or block placement errors is a great advantage of the EPID. The EPID will play an important role in modern radiation therapy in terms of increasing the accuracy of treatments, although further development of both hardware and software is required.

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Purpose: Radiation myelopathy is late injury to spinal cord and should be avoided by radiation oncologists. We analyzed the spinal cord tolerance for permanent radiation myelopathy among long term survivors of esophageal cancer after denitive radiation therapy.
Subjects and Methods: Between 1971 and 1992, 226 patients with esophageal cancer were treated by radiation therapy alone. Of these, 50 patients who survived more than 2 years after radiation therapy were selected for this study. Subjects were 34 males and 16 females aged 47 to 87 (average=72 years old); 5 patients in Ce, 6 in Iu, 20 in Im, 17 in Ei, 2 in Ea; 36 with Stage I-III disease, 14 with Stage IV according to the gross stage of the Japanese Society for Esophageal Diseases. We investigated not only radiation factors such as radiation technique, spinal cord dose (TDF) and field size, but also patient factors such as age, sex, body weight, serum cholesterol level, hemoglobin, blood pressure in relation to radiation myelopathy.
Results: Permanent radiation myelopathy occurred in 4 patients (8.0%) at 12, 24, 36 and 52 months, total spinal cord dose being 70Gy (TDF=115), 69Gy (TDF=130), 71 Gy (TDF=121), 66Gy (TDF=103), respectively. No patients who received less than 60Gy to the spinal cord (TDF=99) developed radiation myelopathy. The risk of myelopathy at each dose level was 0/21 at TDF≤-66 (40Gy), 0/3 at TDF≤82 (50Gy), 0/8 at TDF5≤99 (60Gy), 2/14 at TDF≤115 (70Gy) and 2/4 at TDF≥115 (70Gy). No patients who received a cord dose of TDF<120 developed radiation myelopathy if the cord length irradiated was less than 10cm. Spinal cord doses of the patients who developed radiation myelopathy were larger than the following formula: TDF=-20/3×field length (cm) + 580/3. Spinal cord dose and field size were important factors for radiation myelopathy. In regard to patient factors, only serum cholesterol level lower than 170 mg/dl was a significant factor for myelopathy. However, cholesterol levels of all four patients with myelopathy were within normal limits.
Conclusions: We are not proposing spinal cord dose over 60Gy, but our results provide reassurance to radiation oncologists faced with unavoidable spinal dose of 60Gy for tumor control because of wide tumor extension, kyphosis and deviation of the esophagus which may cause radiation pneumonitis due to off-cord fields. We believe that in the large majority of patients the advantages of 60Gy of tumor and spinal dose outweigh the less frequent disadvantages of myelopathy. Spinal cord dose up to 60Gy was tolerable and minimal tolerance dose (TD5/5) might be over 60Gy using conventional fractionation.

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The effects of post-operative whole pelvic irradiation for FIGO stage IB cervical cancer with or without poor prognostic factors such as pelvic lymph metastases or positive surgical margin status were studied at Yamagata University Hospital.
Thirty-three patients with stage IB cervical cancer were treated with post-operative irradiation from October 1977 to June 1993. Anteroposterior opposed portal whole pelvic irradiation with Linac 4 MV X-ray was performed. The total dose administered ranged from 42 to 52.2Gy (mean: 47.8Gy).
The 5-year survival rate was 96.8 % and the 5-year local control rate was 97.0%. When there were no pelvic lymph metastases, the 5-year survival rate and the 5-year local control rate were both 100%.
From the above-mentioned results a total dose of 45Gy in 5 weeks was considered to be sufficient for local control in the pelvis.
Post-operative whole pelvic irradiation may be beneficial in local control of regional lymph nodes in stage IB cervical cancer even though the patients have no poor prognostic factors.

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One thousand cases with various head and neck diseases have been treated by Gamma radiosurgery at Komaki City Hospital since May 1991. Five hundred and sixty-eight out of 1, 000 cases were neoplastic lesions which consisted of 173 cases of neurinoma, 108 of metastatic tumors, 103 of meningioma, 69 of gliomas, 27 of pituitary adenoma, 26 of craniopharyngioma, 13 of pineal tumors, 11 of chordoma, 6 of malignant lymphoma, 5 of hemangioblastoma and so on. The most effective result has been shown in metastatic brain tumors, The complete response (disappearance of the lesion) was obtained in more than 50% of the treated lesions, and the control rate of 85% was maintained for more than 12 months. Next effective results were shown in craniopharyngioma, malignant pineal tumors and malignant lymphoma. There was a group which showed moderate response but no tumor disapperance. Those were pituitary adenoma, acoustic neurinoma, meningioma and chordoma. Gliomas showed less response and even progression of tumor at relatively higher rate. It has been found that malignant gliomas showed difficult control of the tumor and progression rate of 70%, while benign gliomas showed the control rate of more than 90%. Besides intracranial lesions, malignant skull base tumors such as chordoma, naso-pharyngeal cancer, adenoid cystic cancer showed better response to gamma radiosurgery and higher control rate for longer period of time with high QOL compaired to conventional irradiation.

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To compare the dose rate factor in the brachytherapy for cervical cancer, a questionnaire was sent to 13 facilities in Japan. Data were collected on 551 patients. There were 99 cases in stage I, 232 in stage II and 220 in stage III. Of these 300 cases were treated by the high dose-rate (HDR) technique (stage I: 63, stage II: 123, stage III: 114) and 251 cases by the low dose-rate (LDR) technique (stage I: 36, II: 109, III: 106). The fractionation schedule for intracavitary irradiation was:(a) the HDR group: 6.0±1.1 Gy/fr, and 27.9±4.2Gy of total dose with 4.8 insertions (3-10 times) in 28.2±10 days;(b) the LDR group: 16.9±6.6Gy/fr, 48.0±6.8Gy of total dose with 2.9 insertions (1-5 times) in 21.4±11 days. The tumor CR rate was 81% for all, 83% for the HDR group (stage I: 98%, stage II: 90%, stage III: 68%) and 79% for the LDR group (stage I: 86%, stage II: 85%, stage III: 69%). The 5-year survival rate was 70% for all, 72% for the HDR group (stage I: 87%, stage II: 76%, stage III: 58%) and 68% for the LDR group (stage I: 80%, stage II: 73%, stage III: 59%). There were no statistically significant differences. The incidence of complications according to Kottmeier's grading system were 25.3% for the HDR group and 27.9% for the LDR group (NS). However, there were 20 patients with grade III complications in the HDR group and 12 in the LDR group. Deaths due to complications after irradiation occurred in 7 HDR cases and 1 LDR case. Our data shows that the effect on response and survival rates was equivalent and the dose rate factor was 0.58 over all, 0.57 with midline shield and 0.59 without midline shield.

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The International Commission on Radiation Units and Measurements (ICRU) Report 50 have recommended that one has to force a certain degree of heterogeneity, which today in the best technical and clinical conditions should be kept within+7% and-5% of prescribed dose. To follow this recommendation closely and assure the planning target volume within the 95%-isodose line in applying radiotherapy to early glottic cancer, the author studied how to determine the appropriate radiation field size in the two lateral parallel opposing fields technique. The author defined the superior boundary of the planning target volume at the superior margin of the thyroid cartilage, the inferior boundary at the superior margin of the anterior portion of the cricoid cartilage, the anterior boundary at the posterior surface of the thyroid cartilage, and the posterior boundary at the anterior surface of the cricoid cartilage, respectively. First, the mean size of the planning target area for 25 patients was measured. The average size of 2.8×3.6 cm² was disclosed. Then phantom model experiments were conducted to clarify the appropriate radiation field size for keeping a heterogeneity of dose distribution of the planning target volume within+7% and-5% of central axis depth dose. A radiation field 5 cm in length and 6cm in height seemed appropriate for a target area 2 to 3 cm in width and 2.7 to 3.7 cm in height. However, a smaller or larger target area required a radiation field 4 cm or 6 cm in width, and 5 cm or 7 cm in length. When the distance between the anterior neck surface and the posterior surface of the anterior portion of the cricoid cartilage was less than 5 mm, a low-dose area appeared in the anterior portion of the planning target volume. In such patients, the anterior border of the fi eld should be placed more than 10 mm anteriorly to the anterior neck skin surface.

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In the radiotherapeutic clinic, color photographs are as important as radiographs because they record essential information of visible tumors. From this point of view, a radiotherapy PACS system should be able to accommodate color photographic images. Since July 1993, we have been using a digital still camera system to record tumors at the radiotherapy clinic. An image is displayed on a CRT monitor and the data is digitally stored on an inexpensive 4 mm DAT cassette tape, and a color print can be obtained in one minute. Since November 1993, we have transferred these images to an image database on a Macintosh. This has enabled us to review the changes in a patient chronologically. Although there are some points to be improved, digital photograph is useful and should be broadly used by radiotherapeutic clinics.

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