Is control of the primary tumour worthwhile in non-oat cell carcinoma of the bronchus?

In the United Kingdom most patients with locally advanced non-small cell lung cancer are given treatment with palliative intent only, even when there is a good performance status and an absence of evidence for distant metastasis. It has, however, been shown that after radical radiotherapy prolonged survival can result, but only when complete regression of tumour is achieved. Research has, therefore, been directed toward an increase in primary tumour control. In pilot studies a combination of chemotherapy and radiotherapy has given improvement in tumour clearance and survival. Another approach has been to use a short intensive course of radiotherapy in which three treatments are given each day for 12 consecutive days--Continuous, Hyperfractionated, Accelerated Radiotherapy (CHART); an increase in local tumour control and survival has been shown in a comparison with the results achieved in previous cases. CHART and the combination of chemotherapy and radiotherapy are both the subject of multicentre randomized controlled trials in the United Kingdom. Patients with locally advanced non-small cell carcinoma of the bronchus should be considered for entry into these studies.

Future prospects of radiotherapy in pancreatic cancer

To clarify the role of radiation therapy in the treatment of carcinoma of the pancreas studies with radiotherapy alone, combined interventional or concurrent radio-chemotherapy are reviewed. It is shown that in the case of inoperable tumour radiotherapy alone is inadequate, but by the means of a combination of chemotherapy, external beam or interventional (intra-operative, interstitial) irradiation, improvements in local control rates and median survival can be achieved. Following so-called curative resection, a number of studies have shown that adjuvant radio-chemotherapy or interventional treatments possibly prolong survival.

Recent advances in radiotherapy treatment planning

Radiation treatment planning is currently in a state of rapid change. Dissatisfaction with past planning technology stems from the growing realization that: (1) Increases in the local regional tumor control rate will increase the cure rate in many malignancies. (2) Even at the best treatment centers geometric tumor misses are commonplace. (3) Traditional constraints on treatment techniques, originally imposed for simplicity and reproducibility, are no longer necessary, and can result in suboptimal treatment. (4) Treatment plans judged "optimal" in two dimensions may be far from optimal when viewed over the entire treatment volume. (5) Lack of treatment reproducibility is also commonplace, and can be demonstrated to adversely affect treatment outcome. On the positive side, recent developments in computer graphics, image processing, radiation physics, and radiation biology are now making it possible to define, design, and deliver sophisticated 3D radiation treatments. However, because many of these technologies are being developed for other disciplines, their applicability to radiation therapy treatment planning is not widely appreciated. We outline the current status and new developments in radiation therapy treatment planning.

Trends in conserving treatment of invasive carcinoma of the breast in females

This population-based study presents trends in the treatment of node-negative invasive carcinoma of the breast in females during the 1980s in the Detroit metropolitan area. It was done to determine whether or not there has been a significant shift toward conservation of the breast from 1980 to 1987. Trend analyses of surgical treatment, tumor size, node status, year of diagnosis, age and race were performed for 13,217 patients drawn from the Metropolitan Detroit Cancer Surveillance System. A significant increase in the use of conserving the breast was observed, with younger women receiving this treatment option more often than older women. Implications for a continuing shift in the biologic findings and treatment of carcinoma of the breast are discussed.

[How is it considered to advance radiotherapy from biological and clinical standpoint of view?]

The main reasons of recent advances of radiotherapy are considered to be due to improvements of therapeutic techniques and therapy machines, but the contributions of radiobiology are thought to be no so great. In the present paper, the history of radiotherapy is reviewed, and several problems to be solved in order to make more effective radiotherapy taken in radiobiological factors was discussed.

[Several factors for improving results of radiation therapy]

Various methods have been employed for improving the efficacy of radiation therapy including combined use of radio-sensitizer, chemotherapy, hyperthermia, combination with surgery, intraoperative electron beam therapy, heavy particle therapy, etc. We have evaluated if further improvements in treatment results could be obtained by improving irradiation techniques which are routinely employed in the daily radiation therapy. The results of our evaluation has indicated that therapeutic gains could be raised by: (a) vastly improved radiographic techniques for better visualization of tumor and normal structures, that is, more reliable determination of target volume; (b) improvement of reproducibility of field alignments; (c) improvement of dose distribution by multiportal irradiations.

[Physical considerations on the method for improving the outcome of radiation therapy]

The outcome of radiation therapy is closely related to the dose that has been delivered to the target volume and the organs at risk. In this report, sources of errors in dose delivery and their magnitudes at each step of radiation therapy from data acquisition of patient to execution of irradiation, and the methods for reducing the errors are discussed. The influences of systematic or random errors in the target dose level and of dose inhomogeneities throughout the target volume on the dose-effect curve are also described. To improve the outcome of radiation therapy, a constant effort from radiotherapists, physicists and technicians is required for reducing the systematic and random errors at each step of radiation therapy.

[Problems and future of radiation oncology in Japan]

The present status and various problems of radiation oncology practice and study in Japan are discussed compared with historical development of radiotherapy in the United States. Besides insufficient resources and personal staffing, traditional thinking and cultural habits have been adversely affecting scientific way of thinking, training of professionals, and daily operation as well as study of radiation oncology in Japan. In the current limited situation, palliative treatment and its systematic, original study should be more emphasized to further develop radiation oncology program and to increase credibility of radiotherapy among medical professions in general.

[Basis of radiotherapy for improved tumor control and preservation of normal function]

Historical overview of development of radiotherapy, its biological basis and radiation sources since the discovery of x-ray are presented. The present status and problems as well as future direction of radiation oncology studies such as clinical cyclotron for heavy ions, predictive assays and indicators, and various fractionation schemes are discussed. Better understanding of the current status and problems of various disciplines by each specialist is important for the improvement of combination treatment using different modalities. Also, better understanding of radiotherapy by other specialists and cooperation with each other are the key to the development of rather weak radiation oncology programs in the Japanese medical system.

Failla memorial lecture. Contrarian concepts in the progress of radiotherapy

Radiobiology concepts relevant to radiotherapy have undergone continued revision, suggesting that a continuing skeptical if not completely contrarian view of current concepts is also warranted. Some such revisions are revisited, and some present applications of radiobiology to radiotherapy are discussed before they, too, require revision.

Patterns of change in the physics and technical support of radiation therapy in the USA 1975-1986

Information on the patterns of personnel and related equipment support and availability at various types of radiation oncology facilities are included in the Facilities Master List surveys conducted by the American College of Radiology. This paper summarizes the surveyed data obtained during 1975-1986. The data presented include the use of equipment and the degree of personnel support at government owned, hospital or university based, and freestanding facilities. There is increasing use of linear accelerators, simulators, and treatment planning computers among all types of facilities. The use of 60Co units has been progressively decreasing. Almost all types of facilities show inadequate, but slowly improving, numbers of physicians, physicists, dosimetrists, and technologists when compared with the level recommended by the Blue Book.

Fast neutron therapy clinical trials in the United States

The National Cancer Institute (NCI) began supporting clinical fast neutron clinical studies in the United States beginning in the early 1970s using physics-based cyclotrons and linear accelerators at a number of locations and facilities. The early work pointed out the handicaps imposed by the limitations of horizontal beams and low energy neutrons. This, combined with some encouraging, clinical results using neutrons and photons in a mixed mode of therapy, prompted the NCI in 1979 to initiate a 10-year contract program to design, develop, and build hospital-based neutron therapy machines and to conduct phase III clinical trials. As we approach the end of the 10-year effort, three hospital-based neutron facilities are currently operational-at the University of Washington, Seattle; University of California at Los Angeles: and M. D. Anderson Hospital at University of Texas System Cancer Center, Houston. Phase III trials are in progress in four sites: head and neck, prostate, and lung tumors, and cancers of radioresistant histologies, such as melanoma, renal cell carcinoma, and sarcomas of the soft tissue and bone. The contractors will continue to receive limited NCI support to complete the clinical studies.

The changing role of radiation therapy in the treatment of primary breast cancer

The role of radiation in the management of breast cancer has seen extraordinary change in the past 15 years. The primary treatment of early breast cancer once required mastectomy. Today, a local tumor excision followed by postoperative radiation is an established alternative of equal efficacy. Postoperative chest wall and/or lymphatic irradiation was once nearly routine following mastectomy; later, as adjuvant chemotherapy came into widespread use, its usage declined markedly. Today however, evidence is mounting that the addition of postoperative radiation to adjuvant chemotherapy and surgery can improve local-regional control and survival in selected subsets of these patients. In unresectable breast cancer, radiation was once the primary modality of treatment. Today it is part of a combined modality approach attempting to reduce these patients' high rates of both distant and local-regional failure.

Recent developments in neutron capture therapy

The conditions for the possible initiation of clinical trials with neutron capture therapy at a number of locations in the U.S. is reviewed. There are several new technical developments or plans at the Brookhaven Medical Research Reactor (BMRR), the Power Burst Facility (PBF) at INEL, the Massachusetts Institute of Technology Reactor (MITR) and the Georgia Institute of Technology Research Reactor (GTRR). Emphasis is on the development of epithermal beams for the treatment of deepseated tumors with neutron fluxes in between 10(9) to 10(10) n/cm2s. Therapeutic dose gains, defined as the ratio of tumour dose to maximum normal tissue dose in the treatment volume are expected to be between 2 and 4, depending on the degree of suppression of fast neutron dose. Boron concentrations considered in this case in the tumour are around 35 micrograms 10B/g and tumour/normal tissue concentrations are around 10. The compound development throughout three generations is discussed. The compound proposed nowadays, Na2B12H11SH (or BSH), employed in the treatments in Japan, will likely be replaced in the future by analogous of biomolecules being enriched in the tumour by physiological pathways. Examples are p-boronophenylalanine or boronated porphyrius. The most promising solution envisaged would be the employment of tumour cell specific brononated monoclonal antibodies. Finally the mode of therapy is discussed which will likely be based on a fractioned scheme, to achieve optimized results.

Radiotherapy in China today

The treatment of cancer by radiation in China began in the early 1930's. However, up to 1949, its development was very slow. Following Liberation, the growth of this specialty has been extremely rapid, as shown by the kind of modern radiotherapeutic equipment that is available today in many centers of our country. Currently almost every province has a cancer center with a good radiotherapy department and consequently, treatment results have improved over the past years. Due to the large number of patients seen in every radiotherapy department, many types of cancers are treated each day; thus clinical trials can be concluded in a shorter time. The author will show the kind of work that is being achieved in China in general, and Shanghai in particular.

[Fast neutron therapy in the National Institute of Radiological Sciences; 10 years' experience and future study]

A total number of 1623 patients were treated with fast neutrons produced by bombarding a thick Beryllium target with 30 MeV deuterons between November 1975 and December 1987. The results of clinical trials with fast neutrons have shown that carcinoma of the salivary gland and the prostate and Pancoast tumor of the lung were indications for fast neutron therapy, and that the patients suffering from osteosarcoma, malignant melanoma and soft tissue sarcoma had indications for fast neutrons when fast neutrons were combined with surgery. Neither carcinoma of the pancreas nor glioblastoma multiforme had indications because of complications of normal tissues. High LET radiation therapy will be evaluated by using heavy ions characterized by Bragg peak combined with biological effects.

History, preliminary results, complications, and future prospects of intraoperative radiotherapy

Intraoperative electron beam radiotherapy (IORT) is a new combined modality therapy in the treatment of cancer. IORT is delivered during a surgical procedure to a tumor or tumor bed and areas of possible local regional spread, with the ability to shield or physically move normal tissues and organs out of the treatment volume. IORT is feasible for various intraabdominal, retroperitoneal, pelvic, and other malignancies. It is possible to increase the total radiation dose, thereby improving the therapeutic ratio; a better local control without an increasing morbidity. Although the optimum use of IORT is still unknown, it is believed that its greatest value is in combination with maximal surgical resection of the tumor with or without external beam radiotherapy (EBRT). IORT is still an experimental treatment modality combining surgery, EBRT, and if necessary, chemotherapy. Because IORT is an expensive treatment method, it is important to determine which method is the best and most convenient for the patient. The answer can be given only when prospective, randomized clinical IORT trials and cost-effectiveness studies are initiated.

Is the community radiation oncologist ready for clinical hyperthermia?

The author, in assessing this "new" therapeutic modality, clearly identifies the many problems associated with it and emphasizes its still experimental nature.

Trends in patterns of care for prostatic cancer, 1974-1983: results of surveys by the American College of Surgeons

Data from a recent survey of patterns of care for prostatic cancer sponsored by the American College of Surgeons suggest several trends compared to similar data from a decade ago. The observed differences include increased diagnosis of localized cancer, and increased use of acid phosphatase determinations, bone scans, radical retropubic prostatectomy, radiotherapy (particularly interstitial techniques) and orchiectomy. In contrast, use of bone surveys, perineal prostatectomy and hormonal therapy has decreased. Transurethral resection continues to be the most common means to establish the diagnosis of prostatic cancer but the data do suggest that in more patients the tumors are being staged and graded. Five-year survival rates appear to be improving for all stages, and for white and black patients. Survival of black patients continues to lag behind that of white subjects, presumably owing to the more advanced stage of disease at diagnosis observed in these data. These findings may have important implications for understanding trends in survival of patients with this disease.

Cancer cure with organ preservation using radiation therapy

In 1985, the American Cancer Society has anticipated that 910,000 new cases of invasive cancer will be diagnosed in the United States. More than 37% of those patients can be treated for cure with organ preservation using radiation therapy. The basic biologic background for such an approach to the problem is well established. Clinical data to substantiate the validity of the concept date from 1902 to the present. Without question, organ preservation is becoming a major and important concept in the management of the patient with cancer, and new and innovative techniques for treatment are enabling the organ to be preserved, the cancer to be cured, and appropriate cosmesis and function to be preserved. Many tumor sites are appropriate for this treatment technique, including the breast, the eye, the larynx, and the prostate. In 1985, there has been new emphasis on the successful treatment of cancer with the preservation of the organ intact. The maxim to offer the patient the maximum potential for cure with the minimum complication now has an additional concept related to the opportunity to preserve cosmesis and function.

Future prospects in planning radiation therapy

Recent advances in imaging, especially computed tomography and magnetic resonance imaging, and in the power and capabilities of reasonably priced computers and image display devices will permit a substantial extension of the scope of computer programs designed to help plan cancer therapy. All available diagnostic studies could be incorporated into the process of assessing the patient's disease, picking a treatment modality, and determining details of the selected treatment. Fully three-dimensional simulation of any possible treatment will be possible and methods for comparing and choosing between possible rival plans will be developed. Monitoring of the treatment machine and verification of the adequacy of the delivered treatment will be facilitated, and the follow-up of the patient and statistical analysis of the results of treatment can be incorporated into the overall programming system.

Radiation biology

On a few occasions in the past, radiobiological experiments profoundly influenced the practice of radiotherapy. For example, it was shown in the 1920s that animals could be sterilized without damage to the skin of the scrotum if the testes were irradiated in multiple fractions, whereas in a single dose, sterilization was not possible without significant skin damage. These experiments led to the fractionation patterns used in conventional radiotherapy today. Few experiments have had such a dramatic impact, but since World War II, studies with mammalian cells in culture, transplantable animal tumors, and normal tissue systems produced an impressive body of experimental data. Conventional radiotherapy techniques now can be understood in terms of the basic principles of radiobiology. New horizons in radiotherapy are also suggested. These include the following: (1) altered fractionation schedules, including hyperfractionation and accelerated treatment; (2) the selection of groups of patients likely to benefit from neutrons; and (3) The use of hyperthermia alone or as an adjunct to radiation.

Training in therapeutic radiology in the United States, 1984

The 1984 survey of training programs in Therapeutic Radiology in the United States revealed little change in the number of training programs and the number of residency positions offered. However, there has been a striking increase in the number of residents in training since the survey of 1982. The numbers of residents training in the PG-II and PG-III years are more than 50% greater than any previous survey. The proportion of foreign medical graduates is smaller than reported in 1982, but the proportion of women in residency is unchanged.

Radiation treatment of carcinoma of the vulva, 1950-1980

A retrospective study of all patients with carcinoma of the vulva treated by radiation therapy at the A. Maxwell Evans Clinic of the Cancer Control Agency of British Columbia, between 1950 and 1980, is reported. Sixty-eight patients, representing 30% of all referred patients with vulvar cancer, were analyzed for survival, recurrence patterns, complications, and clinical features. This group is companion to a series of patients treated with operation reported in 1979. The data confirm a major role for radiation therapy both in palliation and in combined radiotherapy-operation. For 13 cases, radiotherapy with curative intent was used in combination with operation resulting in a 5-year actuarial survival of 92%, with acceptable posttreatment morbidity. The advantages of preoperative radiotherapy, particularly for posterior vulvar lesions, are suggested by the data, and the need for a reappraisal of the role of radiotherapy in vulvar carcinoma is stressed.

The eighteenth Douglas Lea lecture. 40 years of radiobiology: its impact on radiotherapy

The contributions of radiobiology to radiotherapy in the past 40 years are reviewed, taking the work of Gray and Read on bean roots with high LET radiation as the starting point. The main impact has been strategic and didactic because methods of measuring parameters in patients so as to affect individual treatments have not yet been developed. Many patients are now being treated with radiotherapy who would have been considered unsuitable 40 years ago and the radiobiological reasons for these changes are discussed. Improvements that have occurred in radiotherapy are reviewed and some projections about future potential improvements are made.

Keynote address: the scientific basis of the present and future practice of clinical radiotherapy

At mid-century radiotherapy was more an art than a science, but is presently based on radiobiological parameters and cell kinetics. This close interaction between basic scientific principles and clinical practice has been made possible because one can correlate quantitatively doses of irradiation with observed responses. First, a short historical review will be made because it gives a perspective for the understanding both of progress made and prevailing misconceptions. The important radiobiological parameters and cell kinetics will then be discussed in some detail to demonstrate that they should be thoroughly understood in their relationship to radiotherapy. The overall treatment planning must be based on the clinical applications of the main radiobiological parameters. The combined treatment with surgery, either pre- or postoperatively, and multiple daily fractionations will be used as examples. The teaching of radiobiology should be considerably expanded, not only for its own scientific merit but also to show how it applies to clinical situations. This should be reflected in the expansion of the board examination.

The changing role of radiation oncology in cancer management

Radiation therapy has made major contributions to the improved quality of care for the cancer patient. This quality improvement has derived not only from a greater understanding of the natural history of the disease process but also from a more critical evaluation of the results of clinical treatment. Today, clinical radiation therapy stands on a firm foundation of basic understanding of ionizing radiations and its effect on tissue, the biology of the effect in normal tissues and tumor. This explosive growth in knowledge relative to radiation therapy physics, clinical treatment planning, the utilization of computers in radiation therapy as well as basic information in radiation biology and how it might be implemented in clinical situations are well known. Data will be presented to illustrate how major and important applications of basic physics and biologic data in clinical practice are beginning to influence the changing character of cancer management. These new techniques, now being implemented in general clinical practice, offer major potential opportunities toward improving the expectation for cure of many cancers, not cured in the past.

Radiation biology: the conceptual and practical impact on radiation therapy

Radiation biology has had an important impact on clinical radiation therapy by providing a rationale for implementation of new treatment strategies and for clinical concepts or practices thereby increasing their acceptance. The observed rather narrow range of D0 and n values for mammalian cells contributed to successful trials of radiation treatment of several "radiation-resistant" tumors, e.g., carcinoma of prostate, color-rectum, and sarcoma of soft tissue. Attention of clinicians was forcibly directed to assessment of local results (local failure, treatment complications) and not merely survival at 5 years by the extensive literature of cell survival curves (in vivo and in vitro) and dose-response assays on normal and tumor tissues. Upon these same laboratory results a scientific rationale was developed for use of shrinking field technique, low dose for subclinical disease, and the combination of moderate dose radiation therapy and conservative surgery. The entire area of clinical research into altered dose fractionation schedules is based upon research on cell proliferation kinetics and repair of radiation damage. The understanding that the time for complete regression of tumor depends not only upon cell kill but also on the pattern of cell proliferation of the progeny of lethally irradiated cells and the abundance of stroma provided a basis for accepting patients with slowly responding tumors for treatment. There remains a wide field of need in research in this area as even today a large proportion of patients who die of cancer die with their cancer uncontrolled at the primary site.