Single radiation dose during surgery 'effective' against breast cancer
A single dose of radiation during surgery appears to be at least as effective as lengthier post-surgery courses of radiotherapy for certain patients with breast cancer, a new clinical trial has found.
Targeted intraoperative radiotherapy (TARGIT) involves a single dose of radiation which is administered to the area of the breast where the tumour has been removed during surgery.
In contrast, standard 'external beam' radiotherapy affects the whole breast and requires a series of hospital visits.
An international team of scientists, including Dr Jayant Vaidya at University College London, have tested the treatment in approximately 2,000 women, aged 45 or older, from nine countries.
All of the patients had been diagnosed with invasive ductal breast cancer - in which the disease grows in the cells that line the ducts of the breasts - and had opted to have breast-conserving surgery.
A total of 996 patients were given intraoperative radiotherapy, while 1,025 received conventional radiotherapy.
However, of the 996 who received intraoperative radiotherapy, 14 per cent (142) subsequently received external beam radiotherapy as well.
After four years, disease recurrence rates were very similar for both treatment groups. Scientists recorded six local recurrences in the TARGIT group and five in the external beam radiotherapy group.
However, major toxicity rates were slightly lower in the TARGIT group (3.3 per cent versus 3.9 per cent), as were radiotherapy toxicity rates (0.5 per cent versus 2.1 per cent).
Writing in the Lancet medical journal, the study authors expressed optimism about the trial results.
They said: "In addition to the obvious benefits of completing all the necessary radiotherapy in a single session at the time of surgery, targeted intraoperative radiotherapy almost completely avoids irradiation of the intra-thoracic structures such as the heart, lung and oesophagus.
"Consequently, the damage to these structures, which can occur even with modern external beam radiotherapy, will have been avoided."
They added: "In countries such as the UK, where the waiting list for postoperative radiotherapy could rapidly diminish with use of targeted intraoperative radiotherapy, we estimate savings of around £15 million a year."
Professor Michael Baum, chairman of the TARGIT-A trial and professor emeritus of surgery at University College London, commented: "It is the sincere hope of the TARGIT group that these results influence a paradigm shift from conventional radiation approaches to single-dose treatment for eligible patients."
Kate Law, director of clinical research at Cancer Research UK, said: "Delivering radiotherapy in a single dose at the time of surgery could potentially have a huge impact for patients, especially if it means getting treatment that is just as effective as the standard therapy in fewer visits to hospital.
"Radiotherapy is already a very effective treatment, so improving that even further is an exciting prospect. Further follow-up of these women will be needed to confirm whether this strategy not only makes the most of the therapy's power but also minimises any long-term side-effects."
- Vaidya, J. et al (2010). Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): an international, prospective, randomised, non-inferiority phase 3 trial The Lancet DOI: 10.1016/S0140-6736(10)60837-9