50 Years of the Radiological Research Accelerator Facility (RARAF).

The Radiological Research Accelerator Facility (RARAF) is in its 50th year of operation. It was commissioned on April 1, 1967 as a collaboration between the Radiological Research Laboratory (RRL) of Columbia University, and members of the Medical Research Center of Brookhaven National Laboratory (BNL). It was initially funded as a user facility for radiobiology and radiological physics, concentrating on monoenergetic neutrons. Facilities for irradiation with MeV light charged particles were developed in the mid-1970s. In 1980 the facility was relocated to the Nevis Laboratories of Columbia University. RARAF now has seven beam lines, each having a dedicated irradiation facility: monoenergetic neutrons, charged particle track segments, two charged particle microbeams (one electrostatically focused to <1 µm, one magnetically focused), a 4.5 keV soft X-ray microbeam, a neutron microbeam, and a facility that produces a neutron spectrum similar to that of the atomic bomb dropped at Hiroshima. Biology facilities are available on site within close proximity to the irradiation facilities, making the RARAF very user friendly.

History of hadron therapy accelerators.

In the last 60 years, hadron therapy has made great advances passing from a stage of pure research to a well-established treatment modality for solid tumours. In this paper the history of hadron therapy accelerators is reviewed, starting from the first cyclotrons used in the thirties for neutron therapy and passing to more modern and flexible machines used nowadays. The technical developments have been accompanied by clinical studies that allowed the selection of the tumours which are more sensitive to this type of radiotherapy. This paper aims at giving a review of the origin and the present status of hadron therapy accelerators, describing the technological basis and the continuous development of this application to medicine of instruments developed for fundamental science. At the end the present challenges are reviewed.

Some physics from 550 BC to AD 1948.

This chapter outlines terminology and its origins. It traces the development of physics ideas from Thales of Miletus, via Isaac Newton, to the nuclear physics investigations at the beginning of the twentieth century. It also outlines the evolving technology required to make the discoveries that would form the basis of radiosurgery. Up to the 1920s, all experiments on atomic structure and radioactivity had involved the use of vacuum tubes and naturally occurring radioactive substances. There was a need to make useable subatomic particles to obtain better understanding of the interior structure of atoms. Because of this, machines that could make atoms move at high speed were invented, known as particle accelerators. A new era had dawned. There is a brief mention of the effect of radiation on living tissue and of the units used to measure it.

Medical physics--particle accelerators--the beginning.

This chapter outlines the early development of particle accelerators with the redesign from linear accelerator to cyclotron by Ernest Lawrence with a view to reducing the size of the machines as the power increased. There are minibiographies of Ernest Lawrence and his brother John. The concept of artificial radiation is outlined and the early attempts at patient treatment are mentioned. The reasons for trying and abandoning neutron therapy are discussed, and the early use of protons is described.

From particle accelerator to radiosurgery.

This chapter outlines the requirements for machines that could perform radiosurgery. It also outlines the characteristics of the narrow beams used for this method. The reasons for limiting human treatments to the pituitary fossa are justified. The experiments, the results of which determined what was possible clinically, are outlined. The two methods of delivery of focused radiation are discussed: Bragg peak and beam crossover.

[History of radiosurgery]. / Historique de la radiochirurgie.

Within the last decades, radiosurgery, also known as stereotactic radiotherapy, has become more and more popular as a non-invasive treatment of small benign tumours, arteriovenous malformations, metastases, and also some functional neurological structures, such as the fifth cranial nerve for trigeminal neuralgesia. It allows precisely delivering very high dose in a small volume under stereotactic conditions with minimal irradiation of tissue around the area. The first equipment devoted to radiosurgery was the Leksell Gamma Knife®. It is now challenged by some linear accelerators providing radiosurgery technology, such as the CyberKnife®, the Novalis Tx® radiosurgery platform, and the True Beam® linear accelerator.

Application of particle accelerators in research.

Since the beginning of the past century, accelerators have started to play a fundamental role as powerful tools to discover the world around us, how the universe has evolved since the big bang and to develop fundamental instruments for everyday life. Although more than 15 000 accelerators are operating around the world only a very few of them are dedicated to fundamental research. An overview of the present high energy physics (HEP) accelerator status and prospectives is presented.

[Fifty-year-old history of cobalt radiotherapy in Hungary]. / Otvenéves a telekobalt-terápia Magyarországon.

The first patient in Hungary was treated by cobalt therapy fifty years ago at the National Institute of Oncology with a Gravicert type equipment. On the occasion of this anniversary, the 50-year history of the Hungarian cobalt therapy is reviewed, and its present role is discussed. The first cobalt unit (Gravicert) was designed by László Bozóky seven years after the first cobalt unit installation in the world in Canada. The megavoltage energy of the Co-60 source (average: 1.25 MeV) resulted in more successful treatments of deep-seated tumors compared to the X-ray therapy. In the next two-three decades, until the widespread use of the high-energy linear accelerators, the Co-60 teletherapy meant the modern radiation treatment throughout the world. Improvements of quality in radiation techniques necessitated exact localization of the tumors and developments of treatment planning methods. At the beginning, the localization was performed with X-ray machines, while the treatment planning was done manually. In 1965 a Rotacert type cobalt unit was installed at our institute. This machine was already capable of making irradiation in multiple directions and it worked in rotating mode, too. In Hungary, more cobalt units - first the Gravicert type, then foreign made machines - were gradually installed in other radiotherapy centers too. The quality of treatments was significantly improved by the introduction of the computerized treatment planning, and the foundation of the IAEA-supported National Treatment Planning Network in 1978 was an important step in this process. The next important development was the commencement of the CT image based treatment planning in 1981. With the spread of modern linear accelerators the role of the cobalt units has greatly decreased by now, however, nearly 2,500 cobalt units are still in use worldwide. Their usage could be further increased with technical developments. At present, radiation treatments are performed with cobalt units in eight out of twelve radiotherapy centers in Hungary.

[The CERN and the megascience]. / El CERN y la megaciencia.

In this work we analyse the biggest particle accelerator in the world: the LHC (Large Hadron Collider). The ring shaped tunnel is 27 km long and it is buried over 110 meters underground, straddling the border betwen France and Switzerland at the CERN laboratory near Geneva. Its mission is to recreate the conditions that existed shortly after the Big-Bang and to look for the hypothesised Higgs particle. The LHC will accelerate protons near the speed of the light and collide them head on at an energy of to 14 TeV (1 TeV = 10(12) eV). Keeping such high energy in the proton beams requires enormous magnetic fields which are generated by superconducting electromagnets chilled to less than two degrees above absolute zero. It is expected that LHC will be inaugurated in summer 2007.

Rethinking Big Science. Modest, mezzo, grand science and the development of the Bevalac, 1971-1993.

Historians of science have tended to focus exclusively on scale in investigations of largescale research, perhaps because it has been easy to assume that comprehending a phenomenon dubbed "Big Science" hinges on an understanding of bigness. A close look at Lawrence Berkeley Laboratory's Bevalac, a medium-scale "mezzo science" project formed by uniting two preexisting machines--the modest SuperHILAC and the grand Bevatron--shows what can be gained by overcoming this preoccupation with bigness. The Bevalac story reveals how interconnections, connections, and disconnections ultimately led to the development of a new kind of science that transformed the landscape of large-scale research in the United States. Important lessons in historiography also emerge: the value of framing discussions in terms of networks, the necessity of constantly expanding and refining methodology, and the importance of avoiding the rhetoric of participants and instead finding words to tell our own stories.

The history and future of accelerator radiological protection.

The development of accelerator radiological protection from the mid-1930s, just after the invention of the cyclotron, to the present day is described. Three major themes--physics, personalities and politics--are developed. In the sections describing physics the development of shielding design though measurement, radiation transport calculations, the impact of accelerators on the environment and dosimetry in accelerator radiation fields are described. The discussion is limited to high-energy, high-intensity electron and proton accelerators. The impact of notable personalities on the development of both the basic science and on the accelerator health physics profession itself is described. The important role played by scholars and teachers is discussed. In the final section. which discusses the future of accelerator radiological protection, some emphasis is given to the social and political aspects that must he faced in the years ahead.

Rolf Wideröe and the development of particle accelerators.

The development of particle accelerators is traced from the simple but ingenious table-top devices conceived during the late 1920s to the present day's large, complex machines which extend over tens of kilometers. The emphasis is on Rolf Wideröe and his seminal contributions to the field. Not only did Wideröe construct the first accelerator which accelerated charged particles to an energy higher than the maximum voltage difference is the accelerator proper, he also invented particle colliders, today's work horse in experimental particle physics.

Particle radiotherapy: historical developments and current status.

The current status of particle radiotherapy from a historical perspective is presented. This is done with a personal view and contains personal references and memories during the development of particle radiotherapy. The particles covered are fast neutrons, neutron capture therapy, protons, helium ions, pions and heavy ions. International cooperation in the development of the field of particle therapy, its impact on radiobiology and conventional radiotherapy, and some personal reflections and conclusions are also presented briefly.

The race for megavoltage. X-rays versus telegamma.

Roentgen's discovery was announced in January, 1896, and x-ray therapy trials followed in 1897. Becquerel rays and radioactive minerals were identified during 1896 through 1898. Radium was used for therapy by 1901, even though a pure standard was not achieved until 1910-1912. Quantities of radium finally became available after 1919, and for 20 years telegamma therapy machines underwent progressive development. Their megavoltage beam was much preferred over the standard 200-250 KV x-ray units of that time. Nuclear physicists during the Great Depression modified electron accelerators into giant 600-900 KV medical x-ray therapy machines and achieved one MV by 1937-1939. These were huge, complex, expensive, and unique to major academic and/or metropolitan centers. During World War II nuclear reactors superseded cyclotrons as efficient factories for few new radioisotopes, including "artificial radium". Few seemed interested in the latter for use in telegamma therapy until 1949-1951, when three competing teams from Canada and the USA designed telecobalt machines. From this competition, among then unknown innovators, emerged three future giants in radiation therapy: A.E.C.L., H. Johns, and G.H. Fletcher. The clinical application of telecobalt therapy was to revolutionize cancer care in community hospitals worldwide.