Stereotactic high dose fraction radiation therapy of extracranial tumors using an accelerator. Clinical experience of the first thirty-one patients.

A stereotactic body frame with a fixation device has been developed for stereotactic radiation therapy of extracranial targets, a precision localization and positioning system in analogy with the stereotactic head frames used for intracranial targets. Results of the first 42 treated tumors in 31 patients are presented. Most of the patients had solitary tumors in liver, lung or retroperitoneal space. Clinical target volumes ranged from 2 to 622 cm3 (mean 78 cm3) and minimum doses to the planning target volumes (PTV) of 7.7-30 Gy/fraction (mean 14.2 Gy) were given on 1-4 occasions to a total minimum dose to the PTVs of 7.7-45 Gy (mean 30.2 Gy) to the periphery of the PTV and total mean doses to the PTVs of 8-66 Gy (mean 41 Gy). The central part of the tumor was usually given about 50% higher dose compared to that of the periphery of the PTV by a planned inhomogeneous dose distribution. Some of the patients received stereotactic radiation therapy concomitantly to more than one target, in others new metastases were also treated which appeared during the follow-up period. We observed a local rate of no progressive disease of 80% during a follow-up period of 1.5-38 months. Fifty percent of the tumors decreased in size or disappeared.

Subcutaneous interleukin-2 and alpha-interferon in advanced colorectal carcinoma. A phase II study.

Subcutaneous administration of low doses of recombinant interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) on an out-patient basis has been reported not to significantly compromise the response frequency compared to intravenous IL-2 in patients with renal cell carcinoma and melanoma. As part of an ongoing program to develop a biotherapeutic concept in patients with colorectal carcinoma (CRC) we studied the clinical effects of such a regimen in 15 patients with metastatic CRC. The daily dose of IL-2 varied between 4.8-14.4 x 10(6) U/m2 and of IFN-alpha between 3-6 x 10(6) U/m2. The cycle length was 6 weeks. The course was repeated every 8 weeks until disease progression. Maximum 4 cycles were administered. Maintenance therapy was given to responding patients once a week every month. No patient showed a major response (CR or PR). Six patients had a stable disease ranging from 3 months to 18 months with a median duration time of 5 months. The median survival of all patients was 13 months. The main adverse reactions were fever, chills, anorexia and shortness of breath. No treatment related deaths occurred. 6/14 patients developed abnormal concentration of serum levels of thyroid hormones. It is concluded that the present treatment schedule using IL-2 and IFN-alpha in advanced CRC seemed not to be of clinical benefit.

Stereotactic radiotherapy of malignancies in the abdomen. Methodological aspects.

A method for stereotactic high-dose radiotherapy of malignancies in the abdomen has been developed. A stereotactic frame for the body has been developed and a method for fixation of the patient in the frame is described. The reproducibility in the stereotactic system of tumours in the liver and the lung was found to be within 5-8 mm for 90% of the patient set-ups. The diaphragmatic movements were reduced to 5-10 mm, by applying a pressure on the abdomen. An analytical method is used to calculate dose distributions for a continuum of beams in an isocentric treatment technique. The advantage of a heterogeneous target dose is demonstrated and proposed for the present application. A non-coplanar treatment technique, using eight individually shaped beams is proposed and has been used for patient treatments. The dose distribution for a patient with a metastasis in the liver is shown as well as dose volume histograms for the target and the liver.

An off-line system for in-time analysis of cardiac catheterization data and for establishment of a cardiological database for retrospective studies.

The system described may be divided in two major parts: (i) automatic analysis of cardiac catheterization data running off-line on a Siemens 305 computer; (ii) storage and retrieval of the results from these analyses and additional data from related departments (thoracic surgery, internal medicine and clinical physiology) in a cardiological database on an IBM 370/155 computer. The first part is described with special regard to (i) operation and control during the phases of data collection, pre-processing, processing and storage of results; (ii) the presentation of the results in a complete and readable form and (iii) the modular design of the software. The results of an evaluation of the computer methods versus manual methods are also presented. The second part has been described with regard to the type of data entered in the cardiological database. The structure of the database and the programs used for storage and retrieval have not been described in detail in the present publication.