In 1990, the CALGB 8433 study showed that survival was improved by sequential platinum-based chemotherapy followed by radiotherapy (CT → RT) when compared with radiotherapy alone for unresectable stage III non-small cell lung cancer (NSCLC). In 1998, the West Japan Oncology Group first reported that survival was significantly prolonged by concurrent chemoradiotherapy (CT+RT) compared with CT → 12T. This superiority of CT+RT was reconfirmed by RTOG in 2000. Therefore, platinum-based CT+RT is now considered the most effective therapy for patients with unresectable stage III NSCLC who have a good PS, adequate lung function and are without pleural effusion. Recently, the new agents of paclitaxel, docetaxel, vinorelbine, irinotecan and gemcitabine have been employed in clinical practice for treatment of NSCLC. Up to now, no phase III study has confirmed which is the best agent for concurrent radiotherapy. However, a new agent in combination with concurrent radiotherapy at a high dose offers the possibility for success, and a platinum-based paclitaxel or docetaxel shows promise in CT+RT. In the near future, since the new oral fluoropyrimidine, S-1, and a selective inhibitor of EGFR tyrosine kinase, gefitinib, have radiosensitizing effects, each of these drugs will be investigated in combination with concurrent radiotherapy. In terms of radiation technique, altered fractionation schemas, particularly hyperfractionated radiotherapy, have not been demonstrated to be superior to conventional fractionation (2 Gy daily up to 56-60 Gy) when employed concurrently with chemotherapy. To reduce radiation-field of the normal lung, state-of-the-art 3D conformal radiation techniques or the proton radiation should be investigated.

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We reviewed 57 patients with intracranial germinoma who were treated with radiotherapy between 1976 and 2001. The median age was 14 years (6-66). The primary lesion was located in the pineal body in 29 patients, the suprasella area in 13, and other sites in 15. Ten patients showed dissemination of the disease. Local irradiation was used for seven patients, local and whole brain irradiation for 36, and whole central nervous system irradiation for 14. The median radiation dose for the primary site was 49 Gy (26-65), for the whole brain 30 Gy (12-54), and for the spine 26 Gy (7-30). Chemotherapy was administered to 10 patients. The 7-year overall and disease-free survival rates were 90% and 84%, respectively. The 7-year failure rates for the primary site, intracranial area and spinal canal were 0%, 9%, 8%, respectively. Recurrence was seen in the intracranial area of four patients, the spinal canal of two, and the abdomen of one. Among the four patients with intracranial recurrence, three were treated with local irradiation or low-dose whole brain irradiation (23 Gy). Of the seven patients who received more than 53 Gy for the primary site and more than 30 Gy for the whole brain, intellectual deterioration was seen in five. Whole brain irradiation may thus be useful for prevention of intracranial recurrence, but high-dose irradiation can lead to a decline in intellectual capability.

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The purpose of this study was to compare radiation doses of small lung nodules calculated with beam scattering compensation and those without compensation in heterogeneous tissues.
Materials and Methods: Computed tomography (CT) data of a phantom model simulating small (1×1× 0.7 cm) and large (3×3.5×5 cm) lung nodules was used in the radiation dose measurements. Radiation planning for a lung nodule was performed with a commercially available unit using two different radiation dose calculation methods: superposition method (with scatter compensation in heterogeneous tissues), and Clarkson method (without scatter compensation in heterogeneous tissues). The energy of he linac photon used in this study was 10 MV and 4 MV. Doses at the center of the radiation field and mean tumor dose calculated with the two methods were compared. Actual dose measurement was performed with a Marcus chamber and the film method, and the measured dose was compared to the estimated (superposition and Clarkson methods) dose of the center of the radiation field.
Results: In a small nodule model, the Clarkson method (Dc) was 107%(4 MV photon) and 132%(10 MV photon) of the measured dose (Dm), while the difference between Dm and the dose estimated with superposition method (Ds) was below 5%. In a large nodule, Dc was 106%(4 MV photon) and 107%(10 MV photon) of Dm, while Ds was 99%(4 MV photon) and 103%(10 MV photon) of Dm. In the comparison of calculated mean tumor doses, Dc was 129%(4 MV photon) and 148%(10 MV photon) of Ds in a small nodule model, while Dc was 112%(4 MV photon) and 113%(10 MV photon) of Ds.
Conclusions: We found that the conventional dose calculation algorithm without scatter compensation in heterogeneous tissues substantially overestimated the radiation dose of small nodules in the lung field. In the calculation of dose distribution of small lung nodules, the scatter compensation in heterogeneous tissues is essential to obtain accurate radiation dose.

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Purpose: The CyberKnife (CK) is a new type of system that is capable of frameless and imageguided robotic controlled stereotactic irradiation. We evaluated the accuracy of irradiation position, radiation dose and distribution.
Methods and Materials: The accuracy of irradiation position: We calculated the accuracy of irradiation position using Gaf-chromic film, a cubic phantom and a head-shaped phantom.
The accuracy of radiation dose and distribution, and as a result of movement of the patient in treatment: We calculated the accuracy by comparing the dose data of the Treatment Planning System (TPS) and EDR2-film in terms of radiation dose and distribution.
Results: The accuracy of irradiation position: The irradiation position errors were 0.31 mm (cubic phantom) and 0.30 mm (head-shaped phantom) on median.
The accuracy of dose and distribution: It was excellent regardless of the collimator size or irradiation methods. As a result of movement of the patient during treatment: No effect was observed in the present assessment.
Summary: The results show that the CK system achieved the same level of accuracy as other devices for stereotactic irradiation. The accuracy of the CK system was satisfactory.

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Purpose: A change of sexuality in patients with uterine cervical carcinoma treated with radiation was investigated.
Materials and methods: The data were collected from 33 patients who received radiation therapy. Inclusion criteria were that patients had partners when they were treated, and they knew their malignant disease themselves. Average age at the treatment was 50.5 years old (26.1-80.5 years), and average age at the observation was 54.3 years old (31.3-80.9 years). Clinical stage of uterine cervical cancer was 8 in stage I, 14 in stage II, 9 in stage III and 2 in stage IV. Twenty cases were treated with radiation therapy alone, and 13 cases were treated with an initial operation plus postoperative radiation therapy.
Results: Except for 5 cases with no sexual activity, frequency of sexual intercourse decreased in 21, no change in 5, and increased in 2 cases. Patients who received radiation alone showed lesser sexual activity than those with postoperative radiation. From the psychological aspect, diminished desire due to an experience of cervical cancer was observed in 21 (65.6%) cases. Nine (31.0%) cases thought that the partners disliked or hesitated at sexual intercourse, whereas 9 (32.1%) cases accepted the requirement from the partner unless the women's desire. Seventeen (63.0%) cases noted that vaginal penetration was difficult, and 24 (75.0%) cases were concerned for the contact bleeding. Seventeen (63.0%) cases noted vaginal pain during the penetration, however, only 3 cases noted intolerable pain. As a result, 13 (52.0%) cases noted orgasmic dysfunction after the treatment for the cervical cancer.
Conclusion: Decreased frequency of intercourse was observed in many patients with uterine cervical carcinoma treated with radiation. The main reasons were not only organ dysfunction such as difficult penetration, contact bleeding or pain, but also an emotional response, such as loss of desire due to cancer history.

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Background and purpose: To achieve the dose distribution corresponding to that in IMRT using a conventional irradiation method, we propose the combination of rectangular rotation irradiation and fixed multiport irradiation (cutting field IMRT).
Materials and methods: One rectangular rotational irradiation port was set at which the dose was set to almost half the prescribedose. Then, 6-10 fixed ports were set. The number of ports or dose weight was relatively large on the posterior side. When hot points appeared, MLC was cut in the most effective direction (cutting field).
Results: Highly conformed plans were made in all clinical cases with reduced radiation doses of OARs. Most plans were made within 30 minutes. RCI was about 0.9 in most cases. Most of the hot points disappeared after adjusting the dose weight and beam orientation.
Conclusions: This method employs conventional technology, so it can be used in a large number of facilities. Each plan was easily made in a comparatively short time even by forward planning. The method can be applied to inverse planning in any area because various templates can be easily fabricated.

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Enhanced acute mucositis is the limiting factor for accelerated, hyperfractionated radiotherapy in head and neck (H&N) Squamous cell carcinomas (SCCs). We have developed a simple, new form of conformal radiotherapy, accelerated multiple arc radiotherapy (AcMAR), which covers the target volume by combined, segmental, and rotational arc fields. Two to three rotational fields were placed with CT guidance, each covering the primary tumor and lymph nodes separately. The optimal inter-isocenter distance was determined by 3D dose calculation. The surface area of oro-pharyngeal mucosa irradiated by more than a 50% dose by this method was reduced by 37-73% compared to that with a conventional parallel opposing technic. Dose searching, randomized two-dose study was initiated in Kitami Red-cross General Hospital (KRCGH) in January 1995, and 101 patients were registered and completed AcMAR in Oct 2000. All the patients were followed for up to 96 months (24-96 mo, Median 48 mo) at the time of analysis. Fifty-one out of 101 patients were Stage III (17) and IV (34). Primary site of tumors were; 38 larynx, 25 oropharynx, 15 hypopharynx, 13 oral cavity, and 10 other miscellaneous sites. Patients were randomly allocated either to Group (A) 60 Gy/24 fr/ bid/3 wks to gross tumor volume (GTV), or Group (B) 66 Gy/33 fr/bid/4 wks to GTV. Forty Gy/16 frlbid/2 wks was given to the volume of “prophylactic” irradiation in both groups of patients. Results were as follows: 1) All the patients, except for one, completed AcMAR without treatment interruption. Acute mucositis at the site of high-dose irradiation was intense; 72% of Group (A) and 62.5% of Group (B) experienced WHO Grade 3 (confluent) mucositis focally. Fifty-one out of 53 in Group (A) and 48/48 in Group (B), however, could maintain oral food intake (WHO Grade 1 or 2) even at the peak of their mucositis, because of the limited area of severe mucositis. 2) With regard to late morbidity, however, 6/46 (followed >24 mo) in Group (A) suffered from mucosal ulceration, two of which resulted in patients' death. No late ulceration nor laryngeal edema was observed in Group (B) patients.(3) Tumor control was impressive and promising; Nine out of 88 (followed >24 mo)“in-field” recurrence, only 3 “outside” failure (two of them were successfully “salvaged” by second RT), and 8 distant failures. Three-year loco-regional control rate was 86.4%, and three-year causespecific, disease-free survival was 77.3%. Our results strongly suggest that an improved tumor control could be obtained when the accelerated fractionation is combined with conformal radiotherapy. The dose limiting acute symptoms was volume-dependent (hence improved by AcMAR), but the late ulceration was not. The size of single fraction should, therefore, be kept with in a certain range.

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The optimal leaf-margin of micro-multileaf collimators in stereotactically-guided conformal treatment was investigated. The margin size of 0-, 1-, 2-, and 3 mm were evaluated for the non-coplanar static conformal beam plan with 6 fields (SCB) and the dynamic arc plan with 5 arcs (DA) about 4 intracranial tumors with various shapes and volume. Non-targeted normal tissue volume irradiated 90% or more, 80% or more, 60% or more, and 40% or more of prescription doses increased straightforwardly as increasing the margin size. The doses cover 95% of the volume of the planning target volume (PTV)(D95) of 0-, 1-, 2-, and 3-mm margin plans were 87-91%, 91-93%, 92-94%, and 92-95% of prescription doses, respectively. Conformity indices of 0-, 1-, 2-, and 3-mm margin plans were 1.1-1.5, 1.2-1.5, 1.2-1.7, 1.4-1.9, respectively. Homogeneity indices of 0-, 1-, 2-, and 3-mm margin plans were 1.2-1.5, 1.2-1.3, 1.1-1.2, 1.1-1.3, respectively. There were no significant differences of planning results between SCB and DA. From the results, a leaf-margin of 1 mm is optimal, regardless of PTV shapes. A leaf-margin of 0-mm is also acceptable, and it is useful for lesions adjacent to organs at risk.

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Purpose: A linear accelerator (linac) takes a leading role in radiation therapy. A linac consists of complicated main parts and systems and it is required that highly accurate operational procedures should be maintained. Operational failure occurs for various reasons. In this report, the failure occurrences of one linac over a ten year period were recorded and analyzed.
Materials and Methods: The subject model was a MEVATRON77 DX67 (Siemens, Inc). The failure rate for each system, the form classification of the contents of failure, the operation situation at the time of failure, and the average performance life of the main parts were totaled. Moreover, the relation between the number of therapies that patients received (operating efficiency) and the failure rate within that number and the relation between environment (temperature and humidity) and the failure rate attributed to other systems were analyzed. In this report, irradiation interruption was also included with situations where treatment was unable to begin in total for the number of failure cases.
Results: The cases of failure were classified into three kinds, (A): irradiation possible, (B): irradiation capacity decreased, and (C): irradiation impossible. Consequently, the total failure number of cases for ten years and eight months was 1, 036, and the number of cases/rate of each kind were (A): 49/4.7%, (B): 919/88.7%, and (C): 68/6.6%. In the classification according to the system, the acceleration section accounted for 59.0% and the pulse section 23.2% of the total number of failure cases. Every year, an operating efficiency of 95% or higher was maintained. The average lives of a thyratron, a klystron, and RF driver were 4, 886 hours, 17, 383 hours, and 5, 924 hours respectively. Moreover, although analysis of the relation between the number of therapies performed (or operating time) and the number of failures for each main machine part was observed, the tendency was not to associate them with each other. The relation between environment and the number of failures, it was observed that in the acceleration and pulse sections, failures increased as climatic temperatures fell.
Results: The cases of failure were classified into three kinds, (A): irradiation possible, (B): irradiation capacity decreased, and (C): irradiation impossible. Consequently, the total failure number of cases for ten years and eight months was 1, 036, and the number of cases/rate of each kind were (A): 49/4.7%, (B): 919/88.7%, and (C): 68/6.6%. In the classification according to the system, the acceleration section accounted for 59.0% and the pulse section 23.2% of the total number of failure cases. Every year, an operating efficiency of 95% or higher was maintained. The average lives of a thyratron, a klystron, and RF driver were 4, 886 hours, 17, 383 hours, and 5, 924 hours respectively. Moreover, although analysis of the relation between the number of therapies performed (or operating time) and the number of failures for each main machine part was observed, the tendency was not to associate them with each other. The relation between environment and the number of failures, it was observed that in the acceleration and pulse sections, failures increased as climatic temperatures fell.

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