Sunao Egawa

Multi-institutional studies on hyperthermia using an 8-MHz radiofrequency capacitive heating device (Thermotron RF-8) in combination with radiation for cancer therapy

A joint clinical trial of hyperthermia using a newly developed 8‐MHz radiofrequency (RF) capacitive heating device (Thermotron RF‐8; developed in cooperation with Yamamoto Vinyter Co. of Osaka) was performed under collaboration of seven institutions. Radiation with 4 Gy twice a week for a total of 40 Gy or 2 Gy five times a week for a total of 50 Gy was delivered. After irradiation, hyperthermia at 42.5°C ± 0.5°C for 40 to 60 minutes was given twice a week for a total of 10 times. Tumors examined in this trial were located in various depths in the body, and included those which were considered refractory to conventional treatments or radioresistant such as malignant melanoma and soft tissue tumors. Of the 63 tumors treated, 52.4% showed complete regression (CR); 19.0% more than 80% regression (PRa); 20.6%, 80% to 50% regression (PRb); and 8.0% no regression (NR). Our joint clinical trial demonstrated that hyperthermia with the use of the Thermotron RF‐8 is safe and effective in the treatment of radioresistant tumors located in superficial, subsurface, and in some cases deep regions, if the surface cooling is properly managed by the temperature‐controlled saline pad and electrodes of appropriate size are paired.

Effectiveness of multimodality treatment for resectable pancreatic cancer

SummarySince November 1983, 16 patients with resectable pancreatic cancer have been treated by a multimodality approach at the National Cancer Center Hospital. This therapy included extended pancreatic resection, intraoperative irradiation by 30 Gy of electrons, and intraoperative hepatic arterial or portal infusion of mitomycin C. Furthermore, postoperative chemotherapy with mitomycin C, using Seldinger’s method or intravenously, was added. The patients consisted of 12 with carcinoma of the pancreatic head and four with carcinoma of the body and tail. The 1- and 3-yr survival rates for these patients were 88 and 53%, respectively. The rates were markedly better than the 26 and 10% after conventional radical pancreatectomy from 1962 to 1983. The cancers consisted of Stage I, 1 case; II, 1; III, 11; and IV, 3 according to the p-TNM pathological classification by UICC, and the 1- and 3-yr survival rates for the 14 patients other than those with Stage I and II were 85 and 57%, respectively. According to our experience, pancreatic carcinoma usually pursues an aggressive course and is unlikely to be cured by surgery alone. A multimodality therapy in addition to radical surgery appears to be necessary in the treatment of resectable pancreatic cancer.

High-dose-rate intracavitary irradiation in the treatment of carcinoma of the uterine cervix: Early experience with 84 patients☆

Eighty-four patients with previously untreated invasive carcinoma of the uterine cervix were treated by high-dose-rate intracavitary irradiation using a remotely controlled afterloading system (Ralstron) with or without external irradiation at the National Cancer Center Hospital, Tokyo, between 1977 and 1981. Survival rates and local control rates were comparable to those for 372 patients treated by low-dose-rate intracavitary irradiation with or without external irradiation from 1972 to 1981 at the hospital. The incidence of major complications was 5.1 and 2.4% for the patients treated by low-dose-rate intracavitary irradiation and by high-dose-rate irradiation, respectively. The results are comparable to those reported by other institutions. We have abandoned the conventional low-dose-rate intracavitary irradiation with the impression that the high-dose-rate remotely controlled afterloading system is a good alternative to the conventional one.

Radiotherapy of T1 glottic cancer with 6 MeV X rays.

We treated 154 patients with T1 glottic carcinoma with 6 MeV X rays through 16 cm2 parallel-opposing open fields on a free set-up delivering a median dose of 67 Gy in 6 2/3 weeks. Observed and relative 5-year survival rates for all patients were 87% and 100%, respectively. The local control rate at 5 years was 89%. Of 18 patients who clinically had local recurrence, 17 were salvaged by a secondary treatment. There were no complications requiring medical or surgical attention. A tendency toward increasing local control rates with increasing total doses was observed in the range between 57.5 Gy and 72.5. No significant correlation was found between local control rates and field size, daily dose, or the technique used. A tendency toward a lower local control rate was noted for patients whose anterior commissures were grossly involved; however, it is not known if this could be attributed to the use of 6 MeV X rays. The results are comparable to those obtained with 60Co as reported in the literature. It is concluded that 6 MeV X rays on a free set-up delivering 65-70 Gy in 6 1/2-7 weeks can be used satisfactorily for the treatment of early glottic carcinoma.

RADIOTHERAPY OF BRAIN METASTASES

The effect of radiotherapy in 254 cases of brain metastases, treated between 1977 and 1984, were studied. The cases included 141 of lung cancer, 28 of mammary cancer, and 85 of other primary sites. The percentages of patients with improvement in clinical symptoms were 8, 39, and 66, respectively. These were groups of patients irradiated with less than 30 Gy, 30 Gy to 50 Gy, and more than 50 Gy. The 50% survival periods from the start of irradiation for the last group were as follows: for radiotherapy only, 4.1 months, radiotherapy and surgery, 4.2 months, radiotherapy and chemotherapy combined, 6.9 months, radiotherapy, surgery and chemotherapy combined, 12.1 months. The intervals between the initial diagnosis and brain metastases were different in lung cancer and mammary cancer, but the prognosis after brain metastases showed little difference between them.

Radiation therapy for advanced gastric cancer

A retrospective study of 75 patients with advanced inoperable gastric cancers, referred to the National Cancer Center Hospital between 1962 and 1982, was performed. According to the Borrmann classification based on X ray findings, Type 1 was found in 3 patients, Type 2 in 5, Type 3 in 40, and Type 4 in 15. Twelve patients could not be classified. The histological type was papillary adenocarcinoma in 7 patients, tubular adenocarcinoma in 23, mucinous carcinoma in 6, poorly differentiated adenocarcinoma in 14, signet ring cell carcinoma in 12 and others in 13. The site of remote metastasis in 19 patients was Virchows lymph node in 8 patients, Douglas pouch in 3, liver and lung in 2 each and others in 4. All patients were treated by a either telecobalt 60 unit or a linear accelerator using 6 Mv photon and the total dose to primary lesion was 4000 cGy in 5 weeks to 7000 cGy in 8-9 weeks. Complete response (CR) was achieved in 6 patients or 8.0%, partial response (PR) in 46 or 61.3%, and no change (NC) in 23 or 30.7%. The response rate based on the sum of CR and PR was about 70%. The 50% survival period in months was 26.5, 7.3, and 3.2, respectively for patients with CR, PR, and NC. For the response of advanced gastric cancer to chemotherapy in the National Cancer Center Hospital, the combined use of UFT and Mitomycin C gave the highest rate, 46%. As for as local response is concerned, the response rate to radiation was 70%, a better result than that of chemotherapy alone.

Dose equivalence for high-dose-rate to low-dose-rate intracavitary irradiation in the treatment of cancer of the uterine cervix

By comparing the incidence of major radiation injury, we estimated doses clinically equivalent for high-dose-rate (HDR) to conventional low-dose-rate (LDR) intracavitary irradiation in patients with Stages IIb and IIIb cancer of the uterine cervix. We reviewed a total of 300 patients who were treated with external beam therapy to the pelvis (50 Gy in 5 weeks) followed either by low-dose-rate (253 patients) or high-dose-rate (47 patients) intracavitary treatment. The high-dose-rate intracavitary treatment was given 5 Gy per session to point A, 4 fractions in 2 weeks, with a total dose of 20 Gy. The low-dose-rate treatment was given with one or two application(s) delivering 11-52 Gy to the point A. The local control rates were similar in both groups. The incidence of major radiation injury requiring surgical intervention were 5.1% (13/253) and 4.3% (2/47) for low-dose-rate and high-dose-rate groups, respectively. The 4.3% incidence corresponded to 29.8 Gy with low-dose-rate irradiation, thus, it was concluded that the clinically equivalent dose for high-dose-rate irradiation was approximately 2/3 (20/29.8) of the dose used in low-dose-rate therapy.

Stage I-II carcinoma of the anterior two-thirds of the tongue treated with different modalities: a retrospective analysis of 244 patients

Treatment results of 244 patients with stage I-II cancer of the mobile tongue were analyzed according to the modalities employed (implantation, surgery, cryosurgery and intraoral irradiation). Overall local control rates at three years were 90 +/- 3% for implant, 89 +/- 7% for cryosurgery, and 84 +/- 9% for surgery. Local control rates in stage II patients treated with intraoral electron irradiation, however, were only 50 +/- 13%. Five-year survival rates were 72 +/- 3% with no significant differences observed in patients with either stage I or stage II regardless of treatment modality. Sixty percent (29/48) of the patients with local recurrences were salvaged by the second treatment. Since the local control and survival achieved by these modalities were similar, with the exception of patients with stage II treated by intraoral electron irradiation, we recommend interstitial implantation with iridium, intraoral electron irradiation or surgery for patients with T1 tumors, and iridium implantation or surgery for patients with T2 tumors. For those with superficial lesions measuring 5 mm or less in thickness, cryosurgery is being offered as an alternative. The patient can choose the treatment modality taking into account his/her age, sex and profession.

Characteristics of the response of soft tissue sarcoma to hyperthermia: The correlation between temperature distribution, radiological examination and histology

Nineteen patients with soft tissue sarcoma were treated by a combination modality of hyperthermia and radiation or chemotherapy. There were 26 treatment sites. The size of the tumours ranged from 2.5 x 2 cm to 24 x 26 cm. Hyperthermic treatments were given twice a week, for a total of five to 14 sessions. Twenty-one tumours were treated by hyperthermia combined with radiotherapy, 2 Gy daily, five times a week, for a total of 40-78 Gy. Three tumours were treated by hyperthermia and arterial infusion of adriamycin, 100-120 mg in five or six treatments. For the superficial tumours the complete response rate was 40 per cent, and for the deep-seated tumours 6.2 per cent. Among the 12 tumours with no response, nine in which the treatment was evaluated as effective histologically (necrosis of the tumour) and by X-ray CT findings (development of a prominent hypodensity area) were included. Six cases were studied to correlate the X-ray CT findings, angiography and histological findings before and after hyperthermic treatment. The data were also used to interpret the thermal curve. The increased hypodensity area was roughly proportional to the development of necrosis, but there was one case in which hypodensity was not correlated with the necrosis. On the contrary, even in the contrast-enhanced area around the tumour in which the presence of residual tumour was strongly suspected clinically, no tumour cells were visualized. Clinical evaluation of the effect by size of the tumour can be supplemented by CT findings and histology, but should be cautiously adopted.

Guide to the use of hyperthermic equipment. 1. Capacitively-coupled heating.

This article is a translated version of the Japanese QA Guide produced by the Japanese Society of Hyperthermic Oncology.