The use of three-dimensional conformal radiotherapy (3DCRT) has now become common practice in radiation oncology departments around the world. Using beam's eye viewing of volumes defined on a treatment planning CT scan, beam directions and beam shapes can be selected to conform to the shape of the projected target and minimize dose to critical normal structures. Intensity modulated radiotherapy (IMRT) can yield dose distributions which conform closely to the three-dimensional shape of the target volume while still minimizing dose to normal structures by allowing the beam intensity to vary across those shaped fields. These IMRT dose distributions can be generated using a number of different delivery methods including static “step and shoot” segmental (SMLC-IMRT) or dynamic sliding window (DMLC-IMRT) approaches using conventional multileaf collimators (MLC) or serial tomotherapy using a special add-on MLC. Results of dose comparisons indicate that IMRT can yield significantly better dose distributions in some situations at the expense of additional time and resources. New technologies are being developed which should significantly reduce the time needed to plan, implement and verify these treatments. Current research should help define the future role of IMRT in clinical practice.

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The history of particle therapy practice started when fast neutron treatment was performed at LBL in 1938. Thereafter, hope and despair followed repeatedly. Based on the initial malpractice at LBL, fast neutron therapy was re-introduced into clinical trial at Hammersmith Hospital, which resulted in an amazingly hopeful outcome. Hammersmith's results encouraged the practice of particle therapy worldwide. Though numbers of huge accelerators were constructed and many extensive clinical trials were undertaken, little absolute gain for fast neutron therapy was demonstrated. The clinical results of boron neutron capture therapy (BNCT) using thermal neutrons from atomic reactors are still far from satisfactory and negative pion therapy failed to show appreciable benefits as expected. Particle therapy practice fell into a temporary depression in the late 1980's. Proton therapy coming after those failures have carefully established its efficacy by demonstrating superb results in limited diseases such as intraocular melanomas and skull base tumors. Recent advances in technology along with evolving needs of society have highlighted particle therapy again. Many new proton treatment facilities have been constructed around the world since the first dedicated proton treatment facility was built at Loma Linda University Medical Center in 1990. Heavy ion therapy has been expected to have superior biological effects to proton therapy. HIMAC at NIRS is the first dedicated heavy ion medical facility which started treatment in 1994 to clarify its use in clinical oncology. Particle therapy has now become eligible in a hospital-based setting and surrounding situations are dramatically changing. Clinical efficacy of particle therapy should be demonstrated in appropriate manners based on the reflection of past history, while its relative cost should not be extremely unequaled to other modalities to justify its existence as an open medical practice in the future.

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Purpose: We evaluated 2 year results of radiosurgery using a linear accelerator for the treatment of cerebral AVM. Angiograms were performed in all cases of AVM before and after SRS, and the relationship between treatment parameters and the ability to achieve local control was analyzed statistically.
Materials and Method: Twenty-four cases of AVM were followed up for more than 2 years and Angiography was performed. The follow-up period was 25 to 60 months (mean, 42 months). There were 10 men and 14 women, ranging in age from 16 to 74 years (mean age, 36 years). Prior to radiosurgery, embolization was performed in 11 patients which reduced the size of the nidus in 8 and reduced blood flow without affecting the nidus size in 3. The nidus ranged in volume from 0.2 mL to 8 mL (mean, 1.7 mL. median, 1.2 mL). The irradiation was performed in a single session. The maximum (central) dose ranged from 21 to 32 Gy (mean, 26 Gy), and the marginal dose ranged from 14 to 22 Gy (mean, 19 Gy). Follow-up magnetic resonance (MR) imaging and CT were scheduled at 6-month intervals for the first 2 years following radiosurgery. One and 2 years after treatment, angiography was performed to evaluate the effects of SRS in all patients.
Results: The nidus completely disappeared in 6 (25%) within 1 year and 14 (58%) within 2 years of the 24 patients. The mean reduction rate was 71 % in 1 year and 91 % in 2 years. Two years reduction rate was significantly higher than the one-year reduction rate statistically. In multiple variate analysis of the two year reduction rate, there are significant differences in nidus volume only (p=0.0235). There were no severe adverse effects in these cases so far.
Conclusion: Radiosurgery using a linear accelerator for AVM can provide good results as good as gamma-knife radiosurgery. Evaluation of AVM treated by SRS should be performed no earlier than two years after treatment.

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Purpose: To evaluate the effect of oral hygiene care of patients with oral cancer on alleviating acute radiation mucositis.
Materials and methods: Eighteen patients receiving postoperative radiotherapy for tongue and oral floor cancer were evaluated. Radiotherapy was given in 2 Gy per fraction, 5 times a week for a total dose of 50 Gy in most patients. Radiation fields included the tongue and oral floor. During radiotherapy, 8 patients were treated by dento-maxillofacial radiologists with special concern on oral hygiene (oral hygiene group) and the remaining 10 patients were treated with routine dental care (standard medication group). Mucositis were evaluated using JCOG grade and EORTC/RTOG score by radiotherapists or dento-maxillofacial radiologists at 10 Gy intervals. Oral hygiene plans comprised motivation to maintain oral hygiene and establishing the habits of oral self care 4 times per day. Once a week, oral hygiene and oral cleaning of patients were checked by dento-maxillofacial radiologists. Oral self care included mechanical tooth brushing and a chemical mouthwash.
Results: No patients with grade 3 and score 4 mucositis were noted in the oral hygiene group. Severe mucositis occurred less frequently in the oral hygiene group than in the standard medication group. Interruption of radiotherapy due to severe mucositis did not occur in the oral hygiene group. On the other hand, interruption of radiotherapy occurred in four patients in the standard medication group, and in three it was due to severe oral pain.
Conclusions: Our results suggested that our method of oral hygiene was more effective for alleviating acute radiation mucositis than other methods so far reported. In addition, our method is considered to be useful in preventing rampant dental caries and severe periodontitis due to the xerostomia induced by radiotherapy.

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We investigated the frequency, degree and risk factors of radiation-induced dermatitis and pneumonitis in 255 patients receiving breast conserving therapy between April 1987 and April 1998.
The majority of the patients underwent a wide excision or quadrantectomy with a level I, II axillary di ssection, followed by radiotherapy consisting of 50 Gy/25 Fr/5 weeks to the preserved breast with a 4 MV beam by tangentially opposed portals using the half-field technique. Eleven patients received an additional 10 Gy/5 Fr of electron therapy to the tumor bed.
Most of the patients developed radiation dermatitis which was limited to reddening or dry desquamation, with the exception of 14 patients with a localized moist reaction. The skin reaction was transient in all patients and improved with conservative treatments. Radiation pneumonitis appeared on chest X-rays in 30 patients, with a slight appearance in 21 and patchy appearance in 9. Three patients presented with persistent symptoms requiring medication. They were treated with steroids, resulting in complete resolution of the symptoms.
A large volume of the chest wall within the irradiation field and a large area of irradiated skin were the risk factors of radiation dermatitis. The volume of irradiated lung significantly correlated with the frequency and degree of radiation pneumonitis. It was preferable that the maximum thickness of the involved lung should not exceed 3 cm. Complicated disease, adjuvant therapy and boost irradiation had no impact on the radiation dermatitis or pneumonitis.

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Purpose: To clarify the effect of concomitant chemotherapy and radiotherapy (CRT) on the survival of patients with locally advanced esophageal squamous cell carcinoma presumed to be inoperable.
Methods: Twenty consecutive patients were treated with 2 courses of CRT. Each course consisted of infusion of cisplatin (70 mg/m²) and 5-fluorouracil (700 mg/m² ×5), and 30 Gy irradiation for 3 weeks (2 Gy/fraction, 5 fractions/week).
Results: Grade 3 organ toxicity developed in 6 patients. Severe side effects included sepsis in 2 patients and esophageal fistula in the other 3 patients. Among the 17 patients who completed the CRT, the tumor showed complete response (CR) in 4 patients, partial response in 8, no change in 2, and progressive disease in 3. Only the complete responders had the therapeutic gain in survival for over a year up to 5 years. Partial responders showed a decline in survival that was as fast as those of the nonresponders. Overall median survival was 194 days.
Conclusion: For inoperable esophageal cancer, combined chemotherapy and radiotherapy has the possibility of inducing eradication of the tumor and long survival at the expense of high rate morbidity.

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A case of multiple pelvic insufficiency fractures is presented. The caseis a 74 year-old woman who was treated with 54 Gy of irradiation following radical hysterectomy forcervical cancer. Twenty years later, multiple pelvic fractures were detected in the irradiated field after conventional radiography of the pelvis. Although a recurrence was suspected, CT scans showed multiple fractures with no mass in the irradiation field, suggesting insufficiency fractures following radiotherapy.
In conclusion, the differential diagnosis of insufficiency fracture should be included for patients with fractures following radiotherapy. A review of the literature of patients with pelvic insufficiency fracture following radiotherapy is also presented.

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Purpose: To evaluate the utility in telemedicine of Three-Dimensional Radiotherapy Treatment Planning (tele-3D-RTP) and to examine the accuracy of isocenter reproducibility in its offline trial.
Materials and Methods: CT data of phantoms and patients in the satellite hospital were transferred to our hospital via floppy-disk and 3D-radiotherapy plans were generated by 3D-RTP computer in our hospital. Profile data of CT and treatment beams in the satellite hospital were pre-installed into the computer. Tele-3D-RTPs were performed in 3 phantom plans and 14 clinical plans for 13 patients. Results: Planned isocenters were well reproduced, especially in the immobilized head and neck/ brain tumor cases, whose 3D-vector of aberration was 1.96±1.38 (SD) mm.
Conclusion: This teletherapy system is well applicable for practical use and can provides cost-reduction through sharing the resources of expensive equipment and radiation oncologists.

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We investigated how many institutions providing radiotherapy in Japan met the guidelines proposed by the Cancer Research group organized under the support of a grant-in-aid from the Ministry of Health & Welfare.
The compliance rate with the guidelines in accordance with the data based on the national survey of the structure of radiotherapy facilities in Japan conducted by JASTRO Database Committee was analyzed for 106 institutions that participated in the Patterns of Care Study (10-17). Almost all institutions have not met the guidelines.
The improvement of the structure of radiotherapy facilities in both manpower and equipment are definitely needed for the future growth of patient numbers of patients who will require radiotherapy in Japan.

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