Yoshihisa Kakuto

PATHOLOGICALLY-PROVEN INTRACRANIAL GERMINOMA TREATED WITH RADIATION THERAPY

BACKGROUND AND PURPOSE A retrospective multi-institutional study was conducted to survey what percentage of intracranial germinomas were treated with pathological confirmation before radiotherapy and to investigate the influence of field selection on outcome. MATERIALS AND METHODS Thirty-seven percent of patients (41 of 110 patients) were pathologically confirmed before radiotherapy during the past 16 years at eight institutions in Northern Japanese prefectures. Pathological confirmation was obtained in 26, 37 and 53% of cases during 1978-1983, 1984-1989 and 1990-1994, respectively. All 110 patients were examined using computed tomography (CT) scans. Among the 41 patients with pathologically confirmed germinoma, radiation fields were craniospinal in 23 patients, whole-brain in 10 patients and local without ventricle inclusion in eight patients. RESULTS For the 41 patients with pathologically confirmed germinoma, the actuarial and cause-specific survival rates were 91/94% at 5 years and 87/90% at 10 years, respectively. The relapse-free survival rate at 10 years was 90. 76 and 22% for the craniospinal field, whole-brain field and local field without ventricle inclusion, respectively. CONCLUSION Pathological confirmation was obtained in only 37% of CT-scan era cases, although the confirmations were more commonly carried out later in the study period. Limited local irradiation alone without ventricle inclusion cannot be recommended for localized tumors even with the help of CT scanning.

Radiation therapy for loco-regionally recurrent esophageal cancer after surgery

PURPOSE To evaluate the treatment outcome of radiation therapy for 33 loco-regionally recurrent esophageal cancer patients. METHODS Between 1988 and 1997, 33 patients with loco-regional recurrence of esophageal cancer after curative surgery received radiation therapy at an average total dose of 61 Gy. The site of recurrence was the supraclavicular region in 14 patients, the mediastinal region in 13 patients, and both the supraclavicular and mediastinal regions in six patients. If patients had ether distant metastasis or malignant pleural effusion, they were excluded from analysis. Patients who received prophylactic postoperative irradiation were also excluded from analysis. RESULTS The median survival period was 7 months. The survival rates at 1, 2, and 3 years were 33, 15, and 12%, respectively. In univariate analysis, patients with a short time interval between surgery and recurrence (P=0.0098) and patients with recurrence in both the supraclavicular and mediastinal regions (P=0.036) had a worse prognosis. In multivariate analysis, the time interval between surgery and recurrence (P<0.001) and age (worse prognosis in younger patients, P=0.019) were the significant prognostic factors. Complete or partial responses were observed in nine (27%) and 21 (64%) of the patients, respectively. Changes in clinical symptoms, such as dysphagia, chest pain and back pain, could be evaluated in 11 patients, and improvement in symptoms was obtained in eight (73%) patients. CONCLUSIONS The prognosis of patients who received radiation therapy for postoperative loco-regional recurrence of esophageal cancer is poor. However, there is symptomatic relief in a significant proportion of such patients, and long-term survival is possible in some patients.

RETROSPECTIVE MULTI-INSTITUTIONAL STUDY OF RADIOTHERAPY FOR INTRACRANIAL NON-GERMINOMATOUS GERM CELL TUMORS

The treatment outcome of 24 patients with pathologically-proven non-germinomatous germ cell tumor was retrospectively investigated to determine the effectiveness of radiotherapy. The patients were divided into three groups as follows: group 1, five patients with mature teratoma with or without germinoma; group 2, six patients with immature teratoma with or without germinoma; group 3, 13 patients with other highly malignant tumors. The overall actuarial survival and relapse-free rates at 5 years were 82% and 59%, respectively, with a median follow-up period of 62 months. The actuarial relapse-free rate at 5 years was 100% for group 1, 63% for group 2 and 44% for group 3. There was no difference in the relapse-free rates between total resection and partial resection. Usage of chemotherapy was adversely related to survival probably due to selection bias. No local failure was observed with 10 Gy or more for group 1,40 Gy or more for group 2 and 54 Gy or more for group 3. In groups 1 and 2, there was no spinal relapses without craniospinal irradiation. In group 3, three of eight patients who did not receive craniospinal irradiation and none of five patients who received craniospinal irradiation experienced spinal relapse. In conclusion, highly malignant GCTs show a high incidence of spinal metastasis and craniospinal irradiation may reduce the risk of spinal metastasis. Radiation dose and volume are to be determined according to the histopathological aggressiveness.

Fatal hemorrhage in irradiated esophageal cancer patients

Between 1980 and 1994, 423 patients with esophageal cancer were given curative radiation therapy. Of these patients, 31 died of massive hemorrhage and were used as the subjects of analysis in this study. The incidence of massive hemorrhage in all patients was 7% (31/423). In the 31 patients who died of massive hemorrhage, 27 had local tumors and two had no tumors at hemorrhage (two unknown cases). The mean time interval from the start of radiation to hemorrhage was 9.2 months. In 9 autopsy cases the origin of hemorrhage was a tear of the aorta in 5 cases, necrotic local tumor in 3 cases and esophageal ulcer in 1 case. The positive risk factors for this complication seemed to be excess total dose, infection, metallic stent, and tracheoesophageal fistula. Chest pain or sentinel hemorrhage proceeding to massive hemorrhage was observed in about half of the patients.

Radiotherapy for malignant fistula to other tract

Radiotherapy was applied to 14 esophageal carcinomas with respiratory tract fistulas using various treatment regimes. Closure of the fistulas was observed in four cases after irradiation at a daily dose of 1.5 GY. The period of closure was transient in two cases but long‐term in the other two. One long‐term closure case underwent low‐dose rate telecobalt therapy (LDRT)(1 GY per hour, 7 GY per day; a total dose of 28 GY) as a boost. His cancer has been well controlled and he is still alive without recurrence at 74 months after fistula formation.

Construction of a remote radiotherapy planning system

BackgroundWe constructed a remote radiotherapy planning system, and we examined the usefulness of and faults in our system in this study.MethodsTwo identical radiotherapy planning systems, one installed at our institution and the other installed at an affiliated hospital, were used for radiotherapy planning. The two systems were connected by a wide area network (WAN), using a leased line. Beam data for the linear accelerator at the affiliated hospital were installed in the two systems. During the period from December 2001 to December 2002, 43 remote radiotherapy plans were made using this system.ResultsData were transmitted using a file transfer protocol (FTP) software program. The 43 radiotherapy plans examined in this study consisted of 13 ordinary radiotherapy plans, 28 radiotherapy plans sent to provide assistance for medical residents, and 2 radiotherapy plans for emergency cases. There were ten minor planning changes made in radiotherapy plans sent to provide assistance for medical residents.ConclusionOur remote radiotherapy planning system based on WAN using a leased line is useful for remote radiotherapy, with advantages for both radiation oncologists and medical residents.

PROGNOSTIC FACTORS IN RADIATION-TREATED ESOPHAGEAL CARCINOMA

Prognostic factors in esophageal carcinoma treated with irradiation were examined. The prognosis of 111 patients without metastasis who had received more than 60 Gy was analyzed. Significant associations were found between survival rates and tumor length, stage, radioresponse of the primary tumor and the s.c. X-P classification based on barium contrast radiography; superficial type (tumor limited to the surface of the esophageal wall), tumorous type (solid mass without ulceration), Ul-A type (tumor with shallow ulceration with regular margin), Ul-B type (tumor with deep ulceration or irregular ulcer margin), and funneled type (tumor invading the esophageal wall in a scirrhous pattern). In multiple regression analysis, the X-P classification had the strongest correlation with survival and the survival rates of patients with the superficial type, the tumorous type and the s.c. Ul-A type were significantly higher than those of patients with the other tumor types (p < 0.001).

Postoperative Irradiation for Esophageal Carcinoma

Postoperative irradiation for curative resection of esophageal carcinoma has been used in order to eradicate micro-dissemination and micro-metastases. Generally, a long T-shaped field is employed for postoperative irradiation, and the risk of radiation myelopathy increases even at low doses when the irradiated volume of the spinal cord enlarges. Some questions arise about the postoperative irradiation: First, whether its effectiveness outweighs the risk; second, for which patients it is indispensable; third, what is the optimal dose of irradiation; fourth, whether combined chemotherapy improves the prognosis; and fifth, what the actual incidence of radiation myelopathy is. We analyzed data compiled over the last decade.