Radiotherapy
BMJ 2001; 323 doi: https://doi.org/10.1136/bmj.323.7321.1107 (Published 10 November 2001) Cite this as: BMJ 2001;323:1107
- R P Symonds, reader in clinical oncology (psymonds@uhl.trent.nhs.uk)
- University Department of Oncology, Leicester Royal Infirmary, Leicester LE1 5WW
Radiotherapy is the art of using ionising radiation to destroy malignant tumours while minimising damage to normal tissue. This treatment can be highly effective. For instance, for early cancer of the larynx the cure rate is over 90%,1 and palliative radiotherapy can reduce or eliminate pain from bone metastases in 80% of patients.2 Although higher doses of radiation can produce better tumour control, the dosage that can be given is limited by the possibility of normal tissue damage. Ulceration, fistulas, severe fibrosis, and strictures may develop months or years after treatment, severely affecting the quality of life. The recent advances described in this paper focus on new techniques that produce the maximum ratio between tumour destruction and normal tissue damage and the increasing participation of patients in treatment planning.3
Methods
A comprehensive literature search looking for recent advances in radiotherapy was not straightforward. Between 1996 and 2001 Medline listed 22 937 articles published in English on human radiotherapy, of which 1878 were listed as reviews. The search was focused on the main topic subheadings (conformal radiotherapy, intensity modulated radiotherapy, combined radiotherapy and chemotherapy treatments, fractionation schedules, and radiosurgery), and this was supplemented by articles from six cancer and three general journals on radiotherapy.
Conformal radiotherapy
The vast improvement in diagnostic imaging has been immensely helpful in treatment planning. If a small portion of the cancer is excluded from the irradiated volume, the treatment is bound to fail. Reconstructed matched computed tomograms and magnetic resonance images can now be used during treatment planning, and this reduces the possibility of “geographic miss.” Moreover, the dose distribution to the target volume can be shaped to conform tightly to the shape of the tumour, reducing the volume of normal tissue irradiated by up to 50% and late damage (side effects developing months or years …