Conformal radiotherapy and molecular imaging: complementary technologies in cancer therapy

This issue of the journal highlights some of the significant advances that have taken place in radiotherapy in recent years. The use of ionising radiation has a venerable history in cancer treatment. The first recorded radiobiology ‘experiment’ occurred in 1898 when Henri Becquerel developed a skin reaction to a vial of radium kept in his shirt pocket. Skin cancers were successfully treated in Stockholm as early as 1899. Throughout the 20th century, rapid technological advances led to the development of orthovoltage x-ray therapy machines, and then in rapid succession, the linear accelerator or ‘linac’ and telecobalt apparatus. The development of computer technology for treatment planning and delivery late in the 20th century and more recently the availability of advanced linear accelerators with multileaf collimators, capable of independent movement, has transformed the capability of radiotherapy to accurately target localised cancers. Radiotherapy has been transformed from a discipline that was in danger of stagnation and was becoming marginalised by the rapid advances in systemic therapy, to a dynamic high-technology therapeutic modality at the centre of combined modality therapy for a majority of the most common cancers. A significant factor in this resurgence of radiotherapy is the recently enhanced ability to precisely deliver therapy to the sites of gross disease and to simultaneously reduce irradiation of healthy normal tissues. This has the potential to