1970s radiobiology

Radiation dose rates

The Mackenzie Davidson Memorial Lecture was given in 1970 by M Tubiana from France (Tubiana BJR 1971; 44(521): 325-347) on the kinetics of tumour cell proliferation. He saw radiotherapy as being at the intersection of radiation physics, oncology and radiobiology. He valued British radiotherapy because of the interest that UK physicists had in biology and that many radiotherapists had towards basic research and technology. In the interesting review he described the many factors influencing tumour cell proliferation.    

Eric J Hall from New York discussed radiation dose-rate in February 1972 (Hall BJR 1972; 45(530): 81-97). Wide ranges of dose-rates had been used in radiobiology and radiotherapy and he considered recent advances with changes in low dosage and high dosage regimens.

Dose-rate spectrum in radiotherapy and radiobiology

Image source: Hall BJR 1972; 45(530): 81-97

Milton Friedman from New York gave another detailed and well-illustrated Mackenzie Davidson Memorial Lecture in 1974 (Friedman BJR 1975; 48(566): 81-96) on radiation biology and radiation pathology. He believed that most radiobiological researchers had been diverted from their most important target, which was to define the inherent character of a cell that makes it radiosensitive. 

 

Effects of radiation on tumur growth

The BJR published many radiobiological studies. In February 1971 Nicholas McNally studied the effects of recovery from sub-lethal damage (McNally BJR 1972; 45(530): 116-120) and in February 1975 he studied the effects of radiation on tumour growth and examined the effect of radiation quality (McNally BJR 1975; 48(566): 141-145).  In April 1977 Juliana Denekamp in an experimental study looked at tumour regression as a guide to prognosis and found that the degree of tumour shrinkage within the period of fractionated irradiation was a useful prognostic guide to ultimate local control (Denekamp BJR 1977; 50(592): 271-279). In August 1977 R Myers and SB Field from the Hammersmith Hospital investigated the response of the rat tail to combined heat and X-rays (Myers and Field BJR 1977; 50(596): 581-586). They found that moderate heat doses would potentiate the effects of X-rays. The effect of heat and X-rays was further explored by Marilyn Law, PG Ahier and SB Field from the Hammersmith Hospital in February 1978 using the mouse ear (Law, Ahier and Filed BJR 1978; 51(602(: 132-138) and they again found that mild hyperthermia when given immediately after irradiation enhanced the radio dermatitis.

 Tumour regression after irradiation

Image source: Denekamp BJR 1977; 50(592): 271-279

 

Effects of radiotherapy

In March 1976 PG Smith and Sir Richard Doll gave a further follow up of the late effects of radiotherapy for menorrhagia and other benign gynaecological conditions (Smith and Doll BJR 1976; 49(579): 777-790). They found that an excess of deaths from leukaemia and cancers was continuing to be observed. They had previously reported in May 1968 (Doll and Smith BJR 1968; 41(485): 362-368). 

The 1974 Silvanus Thompson Memorial Lecture was delivered by RH Mole from the MRC Radiobiology Unit at Harwell (Mole BJR 1975; 48(567): 122-130) reviewed the carcinogenic properties of ionizing radiation. He considered the effects of antenatal radiation and the evidence of atomic bomb survivors.  It may be difficult to believe that the induction of neoplasia by small doses of radiation is more than just a theoretical risk and can actually occur. In the 1970s the evidence had recently appeared to indicate that the breast is more sensitive to the effects of ionising radiation than other tissues and the evidence was reviewed by RH Mole at Harwell in June 1978 (Mole BJR 1978; 51(606): 401-405). Some of the data had come from the long-term follow-up of women who received multiple fluoroscopic examinations for the treatment of pulmonary tuberculosis by artificial pneumothorax. Then at the end of the decade Mole reviewed the radiation effects on pre-natal development (Mole BJR 1979; 52(614): 89-101).

Ionsing radiation as a carcinogen 

Image source: Mole BJR 1975; 48(567): 122-130