Nobuharu Muta

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.

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.

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.

Radiotherapy of bone metastases of a spinal meningeal hemangiopericytoma

Hemangiopericytoma is a rate 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.ZusammenfassungDas Hämangioperizytom ist ein seltener Tumor, der seinen Ausgang von perikapillären Zellen oder Zimmermannschen Perizyten nimmt. Er kann überall dort entstehen, wo sich Kapillaren befinden. Wir berichten über einen Patienten mit meningealem Hämangioperizytom, der zunächst radikal operiert wurde und 20 Jahre nach der Primärbehandlung multiple Knochenmetastasen entwickelte. Der Patient wurde mit gutem palliativen Ergebnis mehrfach bestrahlt.

Argatroban in the treatment of radiation injury of the hand: a case report

Abstract This case report describes a 36-year-old man who accidentally exposed his right hand to ionizing radiation with an energy of 50 kV, 200 mA (estimated radiation dose, 100 to 200 Gy). The short- and long-term effects of exposure to radiation are presented. Treatment was delayed until day 20, and therapeutic interventions thereafter were directed mainly toward the prevention of infection and vascular damage caused by the radiation. The antithrombotic agent argatroban was used to inhibit thrombus formation and facilitate peripheral blood flow, thereby preventing the extension of a necrotic lesion. Macroscopic changes are chronologically reviewed. Although the patient is in good general condition after the accident, he is still under observation for the potential occurrence of delayed aftereffects of the radiation.