[en] A high standard of radiotherapeutic practice must be sought in all phases of management of a patient with malignant disease. Radiation therapy must be appropriately chosen and integrated with surgery, cytotoxic chemotherapy and all other modes of treatment. The most suitable technique with a dose, fractionation and time regime must devised and executed with technical and personal care. Follow-up to truly assess tumor control and morbidity is essential so as to guide the management of future patients. To achieve this in Europe great reliance is placed upon the training and qualification of the therapist and staff. High standards are applied to the professional qualifications for radiation physicists, nurses and technical staff. In the countries belonging to the European economic union, a new Diploma in Radiation Therapy has been established to be a standard for consultant practice through all the countries included. The European Organization for Research and Treatment of Cancer has recently initiated a quality control study in some of the centers included in the Radiotherapy Group. A preliminary report has just appeared on the results of the clinical and dosimetric studies in 8 centers placed in 5 European countries

[en] The goal of radiation therapy is to yield the greatest possible uncomplicated local and regional tumor control. Inasmuch as higher doses of irradiation and adequacy of treatment portals (volume irradiated) appear to correlate with greater probability of tumor control and major complications, there is a critical need to optimize treatment planning and quality assurance in radiation therapy. Along with this, techniques must be developed for reliable patient reposition and immobilization so that the optimized treatment plan can be translated into precise delivery of the irradiation. It is obvious that in clinical trials, the basic parameters of therapy need to be optimally observed, in order to make comparison of experimental arms more reliable. Stringent criteria must be incorporated into the protocol describing the requirements and techniques for planning and delivery of the radiation therapy. Furthermore, the dosimetry checks carried out by the Radiological Physics Center should be an integral part of this program. In some studies it is necessary to do an initial review of dosimetry factors and portal films. Since an increasing number of reports point out that the doses of irradiation delivered and the volume treated may affect therapeutic results, a completed case review should always be carried out. Costs of these programs in clinical trials should be justified since, for a small inveestment, the evaluability rate in a protocol can be incresed by 10%

[en] Radiocolloid internal mammary lymphoscintigraphy (ILM) was evaluated in 364 patients with ovarian carcinoma to determine the frequency of abnormalities in post-operative patients, the association between the results of the lymphoscintigram and known clinical prognostic variables, and to establish whether IML yielded predictive information independent of these variables. Results of IML showed a correlation with established clinical prognostic features and yielded independent prognostic information. The sensitivity and specificity of IML in predicting relapse are 51% and 71% respectively, indicating that a single post-operative IML does not predict relapse or freedom from relapse with sufficient accuracy to make it a clinically useful test even though it provides an independent prediction of relapse

[en] A short history of the International Commission on Radiation Units and Measurements (ICRU) and its main objectives are presented. They now include the development of internationally acceptable recommendations regarding: (1) quantities and units; (2) procedures suitable for the measurement and application of these quantities (as well as the associated uncertainties); (3) physical data needed in the application of these procedures; and (4) definition of terms and concepts used in radiation therapy. One of the most important actions of the ICRU during the last two decades was its recommendation in favor of the introduction of the SI units (International System of Units) in the field of ionizing radiation. Recently published ICRU reports in the field of radiation therapy are reviewed. Reports 23 and 24 provide recommendations for determining the absorbed dose in a patient irradiated with X or gamma ray beams. High energy electron and neutron beams have been considered in Reports 21 and 26 respectively. Report 31 provides a survey of the available anti W values and Report 29 makes recommendations on dose specification for reporting therapeutic irradiation in external beam therapy

[en] Abstracts of the 64 papers presented at the meeting and 88 papers submitted but not presented are included in these proceedings. The papers are grouped in the following subject areas: radiotherapy of neoplasms of the head and neck, central nervous system, gastrointestinal tract, mammary glands, and genitourinary tract; therapy of gynecologic and hematologic neoplasms; hyperthermia; radiobiology (side effects); and reports of clinical cooperative groups

[en] The purpose of the present paper is to compare the rival merits of the heavy particles that have been proposed for radiotherapy. A simplified summary of the data for the five principal heavy ion beams available at the Bevalac, namely the 14 cm range carbon, neon and argon beams with a 4 cm spread out Bragg peak, and the 24 cm range carbon and neon beams with a 10 cm spread out peak is given. It shows the physical dose distribution as well as the biologically effective dose distribution based on RBE values from cell culture data. Results show the oxygen gain factor for the various Bevalac beams of carbon, neon and argon, and the comparable figures for pions having a 10 cm spread peak, and for fast neutrons

[en] Although diagnostic radiology developed rapidly following Roentgen's discovery, limitations on voltage delayed penetrating external radiation therapy until after World War II. Quality assurance has developed in both the USA and Canada in many different institutions. Tolerances for implementation of the prescribed tumor dose have been established. A series of quality assurance procedures for calibration, three dimensional dose distributions, the treatment planning process, and for treatment delivery have been formulated in protocols and their development is sketched briefly. The importance of computerized tomography in treatment planning and computerized record and verify systems in treatment delivery is emphasized

[en] The considerations of tissue response to radiation absorbed dose suggest a need for an accuracy of +/-5% in its delivery. This is very demanding and its regular achievement requires careful quality control. There are three distinct phases to the delivery of the planned treatment: calibration of the radiation beam in a reference situation, calculation of the dose distribution for a patient relative to the reference dose and the delivery of the radiation to the patient as planned. Each has distinctly different quality assurance requirements and must be diligently observed if the desired accuracy is to be achieved

[en] One usually thinks of radiation safety as keeping patient and personnel exposure as low as reasonably achievable; however, radiation protection activities play an important role in quality assurance for both the clinical and physical aspects. Radiation protection has several aspects: The first step is the design of the irradiation device and its shielding. Room shielding design is based on the leakage levels specified by the manufacturer and on levels of scatter and primary radiation impinging on the radiation barriers. Integrity and adequacy of shielding should be verified by survey after unit installation. Installation and periodic testing of interlocks are necessary to assure that nonirradiation conditions can be restored as soon as necessary. Personnel monitoring serves two purposes; to provide a record of personnel exposures and to alert one to unsuspected changes that may have taken place in procedure, shielding integrity, or source location. Area monitoring and survey on a periodic basis also provides knowledge of unsuspected changes in procedure, shielding integrity, or source location. Brachytherapy and the transport of small radiation sources require additional precautionary actions. Protection of patient anatomy not being treated reduces the chance of normal tissue damage and the possibility of carcinogenic effects

[en] Pathophysiologic studies of tumor vascular responses to hyperthermia, radiation or adriamycin given alone or in specific combinations have been made in the cervical carcinoma grown in the transparent cheek pouch chamber of the Syrian hamster. A specially designed chamber containing a compartment for flowing water enabled controlled heating of the tumor and pouch to within 0.2⁰C; the desired temperatures were achieved within one minute. Heating at 42⁰C for 30 minutes was followed, at 1, 5 or 24 hours, by a second heating for 30 minutes at 42⁰C. In addition, the same period of heating was preceded or followed, at 1, 5 or 24 hour intervals, by a single exposure to 2000R or a single intravenous injectionof adriamycin given at a rate of 0.45 mg/100 gm body weight. Of the three modalities, heat appeared to have the greatest acute effect on the tumor vascular system. A single dose of heat produced a rapid but transient constriction followed by a prominent dilation of vessels. Two heating periods given at a 1 hour interval caused persistent stasis in the tumor which progressed to coagulation necrosis. Although heating prior to irradiation or adriamycin, in general, increased the vascular responses to these agents, this sequence gave no tumor control. Radiation or adriamycin given prior to heating had relatively little effect on the vascular response to heating and produced no tumor control except when heat was applied shortly after irradiation. These studies indicate that changes in the microvasculature and perfusion in tumors, in response to hyperthermia alone or combined in specific sequences with radiation, can alter the internal environment of the tumor to produce a greater degree of tumor control than can be attributed to direct cell killing by these agents