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A Terahara

Publications and source records attributed to A Terahara.

At least 19 recordsLinked to original sources

Analysis of the relationship between tumor dose inhomogeneity and local control in patients with skull base chordoma.

PURPOSE: When irradiating a tumor that abuts or displaces any normal structures, the dose constraints to those structures (if lower than the prescribed dose) may cause dose inhomogeneity in the tumor volume at the tumor-critical structure interface. The low-dose region in the tumor volume may be one of the reasons for local failure. The aim of this study is to quantitate the effect of tumor dose inhomogeneity on local control and recurrence-free survival in patients with skull base chordoma. METHODS AND MATERIALS: 132 patients with skull base chordoma were treated with combined photon and proton irradiation between 1978 and 1993. This study reviews 115 patients whose dose-volume data and follow-up data are available. The prescribed doses ranged from 66.6 Cobalt-Gray-Equivalent (CGE) to 79.2 CGE (median of 68.9 CGE). The dose to the optic structures (optic nerves and chiasm), the brain stem surface, and the brain stem center was limited to 60, 64, and 53 CGE, respectively. We used the dose-volume histogram data derived with the three-dimensional treatment planning system to evaluate several dose-volume parameters including the Equivalent Uniform Dose (EUD). We also analyzed several other patient and treatment factors in relation to local control and recurrence-free survival. RESULTS: Local failure developed in 42 of 115 patients, with the actuarial local control rates at 5 and 10 years being 59% and 44%. Gender was a significant predictor for local control with the prognosis in males being significantly better than that in females (P = 0.004, hazard ratio = 2.3). In a Cox univariate analysis, with stratification by gender, the significant predictors for local control (at the probability level of 0.05) were EUD, the target volume, the minimum dose, and the D5cc dose. The prescribed dose, histology, age, the maximum dose, the mean dose, the median dose, the D90% dose, and the overall treatment time were not significant factors. In a Cox multivariate analysis, the models including gender and EUD, or gender and the target volume, or gender and the minimum target dose were significant. The more biologically meaningful of these models is that of gender and EUD. CONCLUSION: This study suggests that the probability of recurrence of skull base chordomas depends on gender, target volume, and the level of target dose inhomogeneity. EUD was shown to be a useful parameter to evaluate dose distribution for the target volume.

Adult

Relief of hemiballism from a basal ganglia arteriovenous malformation after radiosurgery.

A patient with a 3-year history of progressive hemiballism presented with an unruptured arteriovenous malformation (AVM) in the contralateral caudate nucleus and putamen. PET demonstrated a matched reduction of cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in the basal ganglia and adjacent frontal lobe. The patient underwent radiosurgery for the AVM. After a period of no clinical change for 6 months, the movement disorder resolved by month 7 post-treatment. The AVM was successfully obliterated 2 years after irradiation without any significant change in the regional CBF or CMRO2.

Arteriovenous Malformations

High-dose conformal radiotherapy influenced the pattern of failure but did not improve survival in glioblastoma multiforme.

BACKGROUND AND PURPOSE: Although glioblastoma multiforme is clearly radiation-resistant, there is evidence of a dose-dependent response relationship. The purpose of the study was to evaluate the impact of higher dose by rotational multileaf collimator (MLC) conformal radiation therapy. MATERIALS AND METHODS: From 1984 to 1995, 38 consecutive cases with intracranial glioblastoma multiforme were treated using the rotational MLC conformal therapy. There were 25 men and 13 women with a median age of 47 years (12-73 years, mean 46.5 years). Median Karnofsky performance score was 80 (30-100, mean 78.2). Median tumor volume was 64 cc (8-800 cc, mean 110.3 cc). All underwent surgical intervention (only biopsy in 1, partial resection in 13, subtotal resection in 21, and gross total resection in 3). Radiation dose to was 60 to 80 Gy (median 68.5 Gy, mean 68.3 Gy) in 21 patients treated before 1990 and 90 Gy in the 17 patients thereafter. Biweekly i.v. chemotherapy was also administered for both arms. RESULTS: The 1-year, 2-year, 5-year, and 10-year overall survival rates were 75%, 42%, 20%, and 15%, respectively. Univariate analysis showed the initial tumor volume, residual tumor volume, and Karnofsky performance score were statistically significant factors for survival. Only the residual tumor volume was statistically significant by multivariate analysis. The 5-year survival rate of patients with residual tumors of 5 cc or less in volume was as good as 37%. Survival of the 90-Gy Group appeared inferior to that of the Low-Dose Group, though no statistical difference was seen (the 3-year survival was 40% vs. 22%). Local failure was observed in 16 of the 19 recurrences in the Low-Dose Group, whereas it was observed in only 4 of the 13 recurrences in the 90-Gy Group. The difference in pattern of failure was statistically significant. Two patients of the High-Dose Group developed radiation necrosis and one died of it. CONCLUSIONS: The high-dose conformal radiotherapy did not improve survival in the disease, but did change the pattern of failure.

Adolescent

Radiotherapy of bone metastases of a spinal meningeal hemangiopericytoma.

Hemangiopericytoma is a rare tumor arising from pericapillary cells or pericytes of Zimmerman, and can occur anywhere capillaries are found. We describe a patient with a meningeal hemangiopericytoma who was treated with primary surgical resection and experienced multiple bone metastases 20 years after the first treatment. This patient with multiple bone metastases was treated with multiple courses of irradiation and good palliation was achieved.

Adult

Control of epilepsy associated with cerebral arteriovenous malformations after radiosurgery.

OBJECTIVE: To investigate the effect of radiosurgery for symptomatic epilepsy associated with cerebral arteriovenous malformations (AVMs). METHODS: Thirty five patients with unruptured epileptogenic AVMs were studied with a mean follow up of 43.0 months. The duration of epilepsy before radiosurgery ranged from 2 months to 21 years (mean 2.8 years). Fifteen patients showed partial seizures; eight of these had associated secondary generalisation. The remaining 20 patients showed only generalised seizures without preceding focal seizures. RESULTS: At the final follow up examination, 28 patients remained seizure free, whereas seizures continued in seven. Variables significantly associated with continuity of seizures after radiosurgery were the number of seizures before therapy (p<0.01) and duration of epilepsy (p<0.05). According to Engel's classification, the 10 patients with intractable seizures before treatment included five with grade I, four with grade III, and one with grade IV. The frequency of seizures began to decrease several months after radiosurgery; much shorter than the time required for morphological change in the AVMs. CONCLUSIONS: Radiosurgery seems to be beneficial for seizure control in patients with unruptured epileptogenic AVM.

Adolescent

Arteriovenous malformations in the basal ganglia and thalamus: management and results in 101 cases.

OBJECT: Because arteriovenous malformations (AVMs) in the basal ganglia and thalamus are difficult to treat, the authors conducted a retrospective study to determine the best management strategy for these lesions. METHODS: The authors reviewed the management and outcome in 101 patients with AVMs treated between 1971 and 1995. In 15 conservatively treated patients, hemorrhage occurred in 71.4% (annual rate 11.4%), and the morbidity and mortality rates were 7.1% and 42.9%, respectively, during a mean follow-up period of 6.6 years. Total microsurgical resection was performed in 15 patients with no mortality resulting, but motor function deteriorated permanently in three of them (20%). Postoperative morbidity correlated well with the location of the AVM and with preoperative motor function. In cases of lenticular AVMs without motor weakness, a postoperative decrease in motor function was significantly more common than in the remaining patients. In patients with motor weakness before surgery, AVMs in the thalamus or caudate nucleus were successfully resected. Among 66 patients treated with gamma knife radiosurgery, three had permanent radiation-induced neurological deficits, and three others experienced bleeding (new bleeding in one case and rebleeding in two). The treatment-associated morbidity rate was 6.7%, and the actuarial rate of complete obliteration was 85.7% at 2.5 years. In five patients treated with embolization alone, the morbidity and mortality rates associated with the procedure or bleeding were 40% and 20%, respectively. The morbidity and mortality rates in the pre-gamma knife era were 22.2% and 22.2%, whereas those for the post-gamma knife era are currently 10.4% and 1.5%, respectively. CONCLUSIONS: These results indicate that conservatively treated AVMs are more likely to bleed and thus produce a high incidence of patient mortality. Multimodal treatment including radiosurgery, microsurgery, and embolization improved clinical outcomes by making it possible to treat difficult cases successfully.

Adolescent

[Clinical evaluation of heavy-particle radiotherapy using dose volume histogram (DVH)].

Radiotherapy with heavy particles such as proton and heavy-charged particles is a promising modality for treatment of localized malignant tumors because of the good dose distribution. A dose calculation and radiotherapy planning system which is essential for this kind of treatment has been developed in recent years. It has the capability to compute the dose volume histogram (DVH) which contains dose-volume information for the target volume and other interesting volumes. Recently, DVH is commonly used to evaluate and compare dose distributions in radiotherapy with both photon and heavy particles, and it shows that a superior dose distribution is obtained in heavy particle radiotherapy. DVH is also utilized for the evaluation of dose distribution related to clinical outcomes. Besides models such as normal tissue complication probability (NTCP) and tumor control probability (TCP), which can be calculated from DVH are proposed by several authors, they are applied to evaluate dose distributions themselves and to evaluate them in relation to clinical results. DVH is now a useful and important tool, but further studies are needed to use DVH and these models practically for clinical evaluation of heavy-particle radiotherapy.

Elementary Particles

Role of radiosurgery in the management of cavernous sinus meningiomas.

OBJECTIVE: To provide our early experience and philosophy in the utility of radiosurgery in the management of cavernous sinus meningiomas. METHODS: Twenty-five consecutive cases with cavernous sinus meningiomas treated between 1990 and 1995 were reviewed. Three cases were treated with gamma-knife radiosurgery, 15 with preceding surgery and gamma knife, 7 with surgery. Mean follow-up following radiosurgery and surgery were 34.8 and 25.4 months, respectively. RESULTS: The 5-year actuarial tumor control rate following radiosurgery was 85.7% and tumor remission rate was 61.4%. Permanent neurological deterioration after radiosurgery was seen in 1 case (5.9%), whereas newly developed or worsened neurological deficits permanently persisted in 59.1% of patients after surgery. There was a clear correlation between surgical radicality and postoperative morbidity rate. CONCLUSIONS: Gamma-knife radiosurgery is a valuable addition to surgical removal in the treatment of cavernous sinus meningiomas. Combination of non-radical resection and subsequent radiosurgery is recommended to improve treatment-associated morbidity.

Adult

[Gamma knife radiosurgery for metastatic brain tumors: neuropathological report of two autopsy cases and review of literatures].

More than 40,000 cases have been treated with gamma knife radiosurgery, but few neuropathological reports are available. This paper describes two autopsy cases in which the patients had been treated with gamma knife. As these patients died 67 and 24 days after therapy, early neuropathological changes are reported. The first case was a 58-year-old woman diagnosed with multiple brain metastases from breast cancer. One of these lesions, in the medullaoblongata, was irradiated with a gamma knife. Sixty-seven days later, she died from heart failure. The second case was a 69-year-old man diagnosed with multiple brain metastases from lung cancer. One of these lesions, in the pons, was irradiated with a gamma knife. Twenty-four days later, he died from acute renal failure caused by hepatorenal syndrome. In both cases, the irradiated lesions were well demarcated from the undamaged surrounding tissues on light microscopy. Histologically, the tumor cells showed a variety of degenerative changes, such as pyknosis, multinuclear cells, and vacuolar degeneration in the cytoplasm. Fibrosis, more prominent in the first case, was observed spreading in the irradiation field, adhering to the hyalinized and thickened vessel walls. Demyelination was also observed in the first case. As far as we know, this report is the first published description of fibrosis in the radiosurgical irradiation field.

Aged

Dose-volume histogram analysis of high dose rate intracavitary brachytherapy for uterine cervix cancer.

PURPOSE: We retrospectively analyzed the relationship between dose distribution and local control using a dose-volume histogram (DVH) in patients with cancer of the uterine cervix treated by definitive radiotherapy including intracavitary brachytherapy. METHODS AND MATERIALS: Twenty-five patients with squamous cell carcinoma of the uterine cervix who underwent definitive radiotherapy between August 1987 and April 1994 were selected for the present study. They included 15 patients with local control and 10 patients with local recurrence. In principle, these patients were treated with 50 Gy of external beam pelvic radiotherapy and a point A dose of 24 Gy, in four fractions, of intracavitary brachytherapy. The DVHs of tumor volumes were calculated by superimposing three-dimensional (3D) dose distributions on computed tomography (CT) images taken before brachytherapy. RESULTS: Differential DVHs revealed a tendency for the portion of the total tumor volume to which the delivered dose was low to be larger in patients with local recurrence. The tumor volumes and the absolute dose volumes of which the absorbed dose was less than 24 Gy [DV (< 24 Gy)] were significantly larger in patients with local recurrence than those in local control patients (p = 0.02 and 0.03, respectively). The percent DV (<24 Gy) was not significantly different in the two groups. In patients with larger tumor volume, the absolute DV (<24 Gy) was also larger and a strong linear correlation was noted between them. CONCLUSIONS: The analysis of dose distribution of brachytherapy using DVH was useful to evaluate the quality of dose distribution quantitatively. The absolute dose volume was considered more important than the percent dose volume for evaluation of the clinical outcome. Our study suggested that unfavorable dose distribution for the tumor volume in brachytherapy was one of the reasons of poor local control in patients with large tumor volume.

Brachytherapy

Gamma Knife radiosurgery for brain stem metastases: two autopsy cases.

Early neuropathological findings were obtained at autopsy in two cases of brain stem metastasis treated with the Gamma Knife. In both cases, light microscopy radiation changes were strictly localized. Residual tumor tissue in the irradiation field showed marked degenerative changes including multinuclear cells, atypical nuclei and vacuolar degeneration. A characteristic finding in the irradiation field was fibrosis associated with hyalinized and thickened vessels. In more peripheral regions, demyelination and vacuolar degeneration were seen. This is the first report demonstrating extravascular fibrosis in the irradiated field following radiosurgery.

Aged

[Verification of rotational conformation radiotherapy using megavoltage CT scanning].

Although portal imaging is a promising method of verification during static multi-port irradiation, it cannot be applied directly to dynamic irradiation such as rotational conformation with multi-leaf collimator movement. A real-time beam monitoring system based on megavoltage computed tomography scanning has been developed to establish a verification method for the rotational conformation technique. The exit beam through the patient is extracted by the same detector unit as that used for megavoltage scanning during the actual treatment. The beam edge is defined as the 50% level of the maximum dose of the detector array. Megavoltage computed tomography is done after patient setup and just prior to the actual irradiation. Detected beam pathways are overlaid on this image approximately every 1 sec. Therapists can monitor the correlation between the target and actual beam pathways on a real-time computer display. The accuracy of field edge detection has been proven to be less than 2 mm from various measurements. Field errors were identified in two of 54 sessions using this method. Although several limitations remain to be solved, the method presented is an useful tool for treatment verification of high accuracy radiation therapy, particularly rotational conformation irradiation.

Brachytherapy

Radiation therapy in early glottic carcinoma: uni- and multivariate analysis of prognostic factors affecting local control.

PURPOSE: The purpose of this report is to clarify prognostic factors affecting local control of T1 and T2 glottic tumors and to define an optimal regimen for radiation therapy. METHODS AND MATERIALS: Two hundred and ten patients (199 males, 11 females, age range 30 to 86 years with an average of 62 years) with previously untreated invasive squamous cell carcinoma of the glottis were treated with radiation therapy at the University of Tokyo between January 1972 and December 1989. Endoscopic microsurgery was introduced as an integral part of treatment in 1974. From 1974 to 1979 the radiation dose was gradually reduced, reaching a mean of 20 Gy in 2 weeks in 1979. From 1980 to 1983, the total dose increased to 50.4 Gy, with a fraction size of 1.8 Gy, over a mean of 5.6 weeks. From 1984 onward, the mean total radiation dose increased to 60 Gy with a fraction of 2 Gy. RESULTS: Recurrence-free 5 year survival rates for T1a, T1b, and T2 were 79%, 73%, and 67%, respectively. When the relationship between radiation dose and local control rates was analyzed for each year from 1974 to 1989, total doses were strongly associated with local control for patients with T1a disease. Age, sex, daily dose, total dose, radiation machine (Co-60 or 10 MV Lineac), treatment technique (anterior wedged pair or parallel opposed fields), treatment volume, use of endoscopic microsurgery, and involvement of the anterior commissure were examined for effects upon relapse-free survival in T1a disease by uni- and multivariate analysis. Total dose was the only significant factor for T1a disease (p < 0.02). The effect of these variables upon relapse-free survival in T2 disease as well as the effect of cord mobility, and number of involved sites was examined by multivariate analysis. Total dose (p < 0.03), cord mobility (p < 0.05), and number of involved sites (p < 0.04) significantly affected relapse-free survival in T2 disease. CONCLUSION: At least 50 Gy is required for treatment of T1 disease when 2 Gy is used as a daily dose, even if endoscopic microsurgery is performed. Better local control of T2 disease in patients with impaired cord mobility or more than three involved sites leads to an improved prognosis; we recommend doses of at least 70 Gy or use of hyperfractionation in such patients with these factors. Although the daily dose did not significantly affect prognosis in multivariate analyses, 1.8 Gy is not recommended for treatment of T2 tumors instead of 2 Gy.

Adult

Thermoradiotherapy in the treatment of locally advanced nonsmall cell lung cancer.

PURPOSE: To improve the treatment results of locally advanced non-small cell lung cancer (NSCLC), we have been conducting a clinical trial using regional hyperthermia combined with radiotherapy. METHODS AND MATERIALS: Between 1985 and 1990, 19 patients were treated. All cases except one were regarded as initially unresectable. There were 10 Stage IIIA cases and nine Stage IIIB cases. In 10 cases thermoradiotherapy was used definitively, and in the other nine cases preoperatively. Radiotherapy was administered with conventional fractionation. Total dose ranged from 42 to 80 Gy (mean 62.9 Gy) for definitive treatment cases, and 38 to 47 Gy (mean 40.6 Gy) for preoperative cases. Radiofrequency (RF) capacitive hyperthermia was administered twice weekly, immediately after radiotherapy. Total sessions of hyperthermia ranged from 5 to 16 times (mean 9.0) for definitive treatment cases and 3 to 8 times (mean 6.7) for preoperative cases. RESULTS: The results of thermoradiotherapy group (HTRT group) were compared with our historical control group (RT group); initially unresectable Stage III NSCLC irradiated definitively with 50 Gy or more (26 cases), or became resectable after radiotherapy and operated (4 cases). As for initial response, there were 5 complete responses (CRs), 13 partial responses (PRs), and 1 no change (NC) (CR rate 26%, response rate 95%) in the HTRT group, whereas there were no CR, 21 PRs, and 9 NCs in the RT group (CR rate 0%, p < 0.005, response rate 70%, p < 0.05). Overall 3-year local relapse-free survival and survival rate for the HTRT group was 73% and 37%, respectively, and 20% and 6.7%, respectively, for the RT group (p < 0.01, p < 0.01). The rate of death from uncontrolled primary disease for the HTRT group was significantly lower than for the RT group (21% vs. 53%, p < 0.03). CONCLUSION: Although the number of cases is rather small, thermoradiotherapy in the treatment of locally advanced NSCLC is promising in raising resectability, local control, and, thus, long-term survival.

Adolescent

Real-time beam monitoring in dynamic conformation therapy.

PURPOSE: Although portal imaging is a promising method of verification during static multiport irradiation, it cannot be applied directly to dynamic irradiation such as rotational conformation with multileaf collimator movement. A real-time beam monitoring system based on megavoltage computed tomography scanning has been developed to establish a verification method for the rotational conformation technique. METHODS AND MATERIALS: Exit beam through the patient is extracted by the same detector unit as used for megavoltage scanning during the actual treatment. Beam edge is defined as the 50% level of the maximum dose of the detector array. Megavoltage computed tomography is done after patient setup and just prior to the actual irradiation. Detected beam pathways are overlaid on this image approximately every 1 s. Therapists can monitor correlation between the target and actual beam pathways on a real-time computer display. RESULTS: The accuracy of field edge detection has been proven to be less than 2 mm from various measurements. Real-time monitoring is more useful in rotational conformation than in static multiport irradiation due to dynamic movement of the collimator. Field errors were identified in two of 54 sessions using this method. CONCLUSIONS: Although several limitations remain to be solved, the method presented is a useful tool for treatment verification of high accuracy radiation therapy, particularly rotational conformation irradiation.

Brain Neoplasms

Radiation therapy for patients of malignant salivary gland tumors with positive surgical margins.

PURPOSE: Surgery is an essential part of treatment for tumors of the salivary gland, yet there is increasing evidence in the literature supporting the necessity of adjuvant radiation therapy. The patients described in this report were selected to receive postoperative radiation therapy because they were found to have positive margins. We have reviewed their records to identify factors influencing the control of local disease, the development of distant metastases and overall survival, and to define the role of postoperative radiation therapy in patients with positive surgical margins. PATIENTS AND METHODS: A total of 17 patients with malignant tumors originating from the major salivary glands seen between 1970 and 1988 who were treated with surgery and postoperative radiation therapy were reviewed. All patients had positive surgical margins. RESULTS: Overall local control at five years was 65%. Classified by T-stage, local control was obtained in all two patients for T1 disease, in five of six for T2, in four of six for T3, and in none of three for T4. At five years, the ratio of patients free of distant metastases was two of two for T1 lesion, four of six for T2, three of six for T3, and none of three for T4. Five-year survival was obtained in all eight patients with T1 and T2 lesions, four of six for T3, and one of three for T4. Patients with neck nodal metastases present in the neck at admission did worse than those with negative nodes, with 0% (none of three patients) free of locoregional recurrence vs. 71% (eleven of 14), 0% (none of three) free of distant metastases vs. 63% (nine of 14), and 0% (none of three) survival at five years vs. 93% (13 of 14). CONCLUSIONS: Postoperative radiation therapy for patients with positive surgical margins was effective for T1 and T2 disease. However, patients with T3 and T4 disease require more aggressive therapy. Patients with nodal metastases in the neck at admission tended to have distant metastases and had poor prognoses. Further therapeutic measures using adjuvant chemotherapy might be explored for these patients. Patients with adenoid cystic carcinoma with positive surgical margins tended to have perineural invasion and distant metastases. However, the utility of chemotherapy for patients of adenoid cystic carcinoma with distant metastases remains uncertain, because effective drugs for adenoid cystic carcinoma do not exist and patients live for several years without chemotherapy.

Adolescent

Wide variation of probability of local failure and distant metastasis among various stages of patients with nasopharyngeal carcinoma.

PURPOSE: Although radiation therapy is the mainstay of therapy in nasopharyngeal carcinoma (NPC), the optimal dosage schemes for treating the primary tumor or cervical lymph node metastases have not been generally agreed upon. NPC is thought to be a tumor well suited to treatment with adjuvant chemotherapy because distant metastases are more common than with other head and neck sites. However, there are several reports that fail to demonstrate improved survival in chemotherapy treated patients. Careful selection of patients for chemotherapy may be required in order to show a benefit. PATIENTS AND METHODS: A total of 61 patients with nasopharyngeal carcinoma seen between January, 1972 and December, 1985 who were treated with radiation therapy alone were reviewed. We analyzed the factors influencing distant metastasis and primary control. RESULTS: The five-year survival rate for observed and relapse-free survival were 44% and 31%, respectively. The survival rates for N3 in TNM classification and for N3 in Ho's classification were significantly worse and distant metastasis rates were significantly higher as compared with N0, N1, N2. 16 of 25 patients who had distant metastases developed them following locoregional failure. No patient with N0, N1, N2a, N2b developed distant metastases without a locoregional recurrence. There were several recurrent cases in which radiation was terminated when tumor disappeared at inspection or palpation. The five-year survival rates for T4 was 0%. CONCLUSION: The patients with N3 in TNM. Ho's classification or locoregional failure may be candidates for chemotherapy, because they have a high probability of distant metastasis. CT should be used in T staging routinely to exclude tumor involvement of the base of the skull. 70 Gy may be appropriate for T3 disease, even if tumor disappeared at lower doses. More than 70 Gy may be required to treat T4 tumors. 50 Gy may be appropriate for N0, N1 and N2b and 70 Gy for N2c and N3, even if tumor was not palpable at lower doses.

Carcinoma, Squamous Cell

Analysis of the results of combined therapy for maxillary carcinoma.

BACKGROUND: Maxillary sinus carcinomas usually are locally advanced. A wide variety of modalities, including surgery, radiation therapy, and intraarterial chemotherapy, alone or in combination, have been used. However, there is still much controversy with regard to the optimum treatment. METHODS: From 1972 to 1986, 108 patients with squamous cell carcinoma of the maxillary sinus were treated at the Department of Radiology, University of Tokyo Hospital. From 1972 to 1974 (the first period), the treatment consisted of operation for reduction of tumor volume, daily cleaning of the maxillary antrum, 20 Gy of postoperative radiation therapy, and intraarterial infusion of 1500 mg of 5-fluorouracil (5-FU) and 3000 mg of 5-bromodeoxyuridine (BUdR). From 1975 to 1979 (the second period), the radiation dose was reduced to 10 Gy, and intraarterial infusion of 5-FU and BUdR was not performed. Surgery for reduction of tumor volume and daily cleaning of the antrum played a major role in this period. From 1980 to 1982 (the third period), daily cleaning of the antrum was not performed. Instead, the dose of radiation was increased to 50-60 Gy. From 1983 to 1986 (the fourth period), more extensive surgery to resect the tumor en bloc was introduced. The radiation dose was increased to 70 Gy. Intraarterial infusion of 3750 mg of 5-FU and 120 mg of cisplatin also was administered. RESULTS: The 5-year survival rate was 46% in the first period, 24% in the second period, 7.2% in the third period, and 53% in the fourth period. In the third period, there were more cases in which death resulted from a cause other than local failure, such as distant metastasis, pneumonia, or secondary primary cancer. Since 1984, we planned treatment with computed tomography (CT) and used the linear accelerator with a multileaf collimator to treat patients with an irregular field of irradiation. These have made it possible to administer radiation therapy in doses as high as 70 Gy without severe complications and improve the survival rate, especially for T4 disease. CONCLUSIONS: Radiation plays an important role in sterilizing malignant cells that cannot be removed by operation. The dose of radiation should be determined according to the volume of residual tumor. Careful treatment planning is required to irradiate the tumor adequately and reduce complications.

Antineoplastic Combined Chemotherapy Protocols