Megavoltage therapy
Many changes in radiotherapy took place in the 1950s including the increasing adoption of megavoltage therapy, the discovery and use of the oxygen effect, the gradual cessation of the practice of radiotherapy for benign diseases and the start of cancer chemotherapy. Megavoltage therapy, initially from telecobalt units and then using linear accelerators, became the mainstay of external radiotherapy. Increasingly sophisticated simulators were used for treatment planning. Whilst the use of the oxygen effect was beneficial it was difficult practically and was replaced by using hypoxic cell sensitizers in the 1960s.
The 1952 Silvanus Thompson Memorial Lecture was given by Ralston Paterson from Manchester on studies in optimum radiation dosage (Paterson BJR 1952; 25(298): 505-516). This is an important topic and one to which he had devoted his professional life. His approach was statistical in this talk but he also emphasised that the danger of a statistical approach was that we could forget that the statistical units represent real men and women. Statistics if misused may deceive but they can illuminate. The “Manchester Method” for treating cervical cancer was revised by Margaret Tod and WJ Meredith in May 1953 (Tod and Meredith BJR 1953; 26(305): 252-257) having been first described by them in 1938 (Tod and Meredith BJR 1938; 11(132): 809-824).
The surgeon Sir Stanford Cade reviewed the role of radiotherapy in laryngeal cancer in his Mackenzie Davidson Memorial Lecture of 1951 (Cade BJR 1951; 24(287): 582-588). Radiotherapy was for early cases of laryngeal cancer and surgery was used for radiotherapy failures. The BJR Supplement No.3 of 1949 was devoted to laryngeal cancer. The 1953 Mackenzie Davidson Memorial Lecture was given by BW Windeyer from the Middlesex Hospital on thyroid cancer and its treatment (Windeyer BJR 1954; 27(322): 537-552).
Image source - survival rates of thyroid cancer 1948: Windeyer BJR 1954; 27(322): 537-552)
The results of treatment
Ralston Paterson and Margaret Tod from Manchester considered the presentation of the results of cancer treatments in March 1950 (Paterson and Tod BJR 1950; 23(267): 146-150) and Jack Boag discussed the clinical features in June 1951 (Boag BJR 1951; 24(282): 299-304). R McWhirter discussed results of the treatment of breast cancer using simple mastectomy and radiotherapy in a paper of March 1955 (McWhirter BJR 1955; 28(327): 128-138). There was considerable controversy in the role of radiotherapy in breast cancer treatment. McWhirter made the important point that the only realistic survival rates are those based on all cases and not on a selected group. If all cases are considered then it became apparent that radical mastectomy alone failed in a very high proportion of cases.
Chemotherapy
In the September 1951 BJR a symposium on the reticuloses was published. Papers on X-ray treatment were printed followed by a paper by Robert McWhirter from Edinburgh on chemotherapy in malignant disease (McWhirter BJR 1951; 24(285): 503-507). Chemotherapy opened up a new approach to the treatment of malignant disease. The agents included nitrogen mustards, urethane, folic acid antagonists and stilbamidine. The subsequent papers looked at nitrogen mustard (Nabarro BJR 1951; 24(285): 507-510) and aromatic nitrogen mustard (Galton BJR 1951; 24(285): 511-513) in the treatment of reticuloses, and nitrogen mustard in the treatment of Hodgkin’s disease (Boland BJR 1951; 24(285): 513-515).
Radiation protection
Frank Ellis was concerned about the genetic risks of ionising radiation in the late 1940s (Ellis BJR 1948; 21(241): 1-4) and returned to the topic in January 1950 (Ellis BJR 1950; 23(265): 28-34) discussing the medical aspects of radiation protection. The following paper by John Nuttall discussed the hazards to radiotherapy departmental staff (Nuttall BJR 1950; 23(265): 35-40) and then A Glücksmann from Cambridge discussed cytological aspects of radiation protection (Glücksmann BJR 1950; 23(265): 41-45) seeing radiation as an “intracellular poison.” In the early 1950s there was an increasing concern about the maximum permissible dose that could be received by workers using ionizing radiation. The doses received by the therapist during the uses of radium were not insignificant and these were examined by JL Howarth and others from Sheffield in April 1950 (Howarth, Miller and Walter BJR 1950; 23(268): 245-255). WV Mayneord reviewed modern radiation hazards in clinical practice in January 1951 (Mayneord BJR 1951; 24(277): 6-11). The use of the new radioisotopes had introduced new problems and had also intensified old ones. The skin reactions in workers who filled radon tubes were described and illustrated by HD Griffith and others from Aberdeen in February 1954 (Griffith, Philip and Swindell BJR 1954; 27(314): 107-112). GM Ardran and FH Kemp from Oxford then described two patients with chronic radium poisoning in November 1958 (Ardran and Kemp BJR 1958; 31(371): 605-610).
Mayneord gave the Silvanus Thompson Memorial Lecture in 1951 and spoke on some problems of radiation protection (Mayneord BJR 1951; 24(286): 525-537). Concerns were to increase in the 1950s and the topic remains vitally important.
Image source: Mayneord BJR 1951; 24(286): 525-537
Radiotherapy equipment
AH Minns and DH Donaldson from Watson & Sons Ltd. discussed the recent advances in radiotherapy apparatus in February 1950 (Minns and Donaldson BJR 1950; 23(266): 125-135). They reviewed apparatus used in the whole radiation spectrum from 5kV to 2MeV. John Read had reported about super-voltage apparatus in 1936 (Read BJR 1936; 9(101): 324-334) and (Read BJR 1936; 9(103): 442-455). By 1950 there were two main types of super-voltage apparatus – the resonance transformer type and the electrostatic generator (Van de Graaf). The apparatus was expensive and it was said in the USA that if you have enough “mega-bucks” you could have a corresponding number of mega-volts!
The electrostatic generator (Van de Graaf)
Harold Miller from Sheffield described a 2MeV Van der Graff electrostatic generator for therapy in December 1950 with a full description of the apparatus (Miller BJR 1950; 23(276): 731-739). In April 1956 KF Orton published their clinical results (Orton BJR 1956; 29(340): 186-192).
The unit at the Royal Cancer Hospital was described by RM Wheatley and others in February 1953 (Wheatley, Hodt and Savage BJR 1953; 26(302): 58-62) and was profusely illustrated.
The cobalt unit
In June 1952 a series of papers from Canada were published describing the use of cobalt and an editorial suggested that a strong case could be made for importing these units (Roberts BJR 1952; 25(294): 281). A 1000-curie cobalt had been installed in Saskatoon in August 1951 and HE Johns and others described the new apparatus in June 1952 (Johns, Bates and Watson BJR 1952; 25(294): 296-302). The cobalt unit offered a source of penetrating radiation without the difficulties of the current complex high-voltage equipment. The unit at the Royal Cancer Hospital was described by CA Greatorex in October 1953 (Lederman and Greatorex BJR 1953; 26(53): 525-532) and was profusely illustrated.
Image source: (Lederman and Greatorex BJR 1953; 26(53): 525-532
The linear accelerator
The 8MeV linear accelerator at the Hammersmith Hospital was installed in 1952 and was the first to be installed in a hospital and was the prototype of the British machines to follow. It was described in May 1955 by GR Newbery and DK Bewley (Newbery and Bewley BJR 1955; 28(329): 241-251). In April 1956 the preliminary clinical results were published (Morrison, Newbery and Deeley BJR 1956; 29(340): 177-186). The history of the linear accelerator started before WW2 when therapy was practiced with radium or with X-rays up to 250kV. The need for higher energies was recognised. The use and history of the machine was described by DK Bewley in the BJR for March 1985 (Bewley BJR 1985: 58(687): 213-217), the accelerator having been switched off for the last time on 10 February 1984 due to the dangerous condition of the building!
Caesium beam unit
The Caesium Beam Unit at the Westminster Hospital was described and illustrated by JE Burns and others in April 1959 (Burns, Perry, Pierce, Trotman and Wilson BJR 1959; 32(376): 215-223). Caesium had been made available in 1954. The unit when delivered had an activity of 1050 curies. In the following paper by HE Johns and others from Toronto their Caesium Teletherapy Unit was described (Johns, Hunt and Skarsgard BJR 1959; 32(376): 224-232). The first large caesium unit had been put into operation in early 1955.
