one-shot radiotherapy for breast cancer?
In a major breakthrough, a team of British doctors headed by University College London's Dr Jayant S Vaidya -- an Indian from Goa -- has succesfully created and tested a new technique that will blast the remnants of a tumour inside the breast in just one shot, lasting half an hour. The team used radiation on areas just around the tumour rather than the whole breast, as is done presently.
A 10-year trial of this Targeted Intraoperative Radiotherapy (TIR), conducted in nine countries involving over 2,200 women, confirmed that radiation targeting a specific area of the breast was as effective as whole-breast radiation in reducing breast cancer recurrence in women.
The results of this trial was published in the latest edition of the medical journal 'The Lancet'.
So, while a patient is still under anaesthesia following the removal of the tumour, a series of gentle X-rays are administered to destroy any remaining tumour cells at the cancer site. The technique is highly convenient, requiring just one session of radiation, making it less time consuming and less costly than whole-breast treatment.
"TARGIT trial can change two fundamental principles in the treatment of breast cancer: whole breast radiotherapy can be replaced by a targeted one-time shot and a much smaller dose of radiation may be adequate," Dr Vaidya told TOI from UK. Several hospitals in India, including Breach Candy in Mumbai and AIIMS in Delhi, have expressed interest in his work, he added.
"Breast cancer usually recurs around the area where the tumour was detected the first time. So it's logical to give concentrated dose of radiation to the tissues at highest risk of cancer coming back rather than the whole breast," he added.
Dr Vaidya said that since 2000, the team started delivering TIR to patients. A special machine called Intrabeam administered radiation from inside the breast to the exact site of the cancer, instead of the present-day external beam radiotherapy.
"Our decade-long TARGIT trial has now confirmed that old and new methods are as good as each other," Dr Vaidya said.
The therapy, however, has a few limitations at present. It can be done on patients over the age of 45 and the tumour should not be bigger than 3cm. "Our trials till now tried this technique on women above age of 45. So we don't know how effective it will be in stopping recurrence of cancer on younger women. Trials to find this are going to start soon," he said.
Dr Vaidya launched the TARGIT trial on March 24, 2000. In this randomized trial, women aged 45 years or older with breast cancer undergoing breast-conserving surgery were enrolled from 28 centres in nine countries. Patients were randomly assigned in a 1:1 ratio to receive TIR or whole-breast external beam radiotherapy.
The study said, "At four years, there were six local recurrences in the intraoperative radiotherapy group and five in the external beam radiotherapy group. Recurrence in the conserved breast at four years was 1.2% in the targeted intraoperative radiotherapy and 0.95% in the external beam radiotherapy group. Radiotherapy toxicity was lower in the TIR group."
Prof Michael Baum, professor emeritus of surgery at University College London who carried out the first procedure using intraoperative radiotherapy in 1998 said, "Many women specially in the developing world who live hundreds of miles from a radiotherapy unit will be spared six weeks of treatment going back and forth to the radiotherapy centre."
* Targeted Intraoperative Radiotherapy (TIR) has a comparable recurrence rate of around 1% with presently used external beam radiation
* Radiotherapy toxicity were four times lower, with an incidence rate of 0.5% compared with 2% from EBR
* The new technique involves an intense blast of radiation to the tumour site extending to a radius of 2 cm lasting 30 minutes
* It takes place after the surgeon has taken out the tumour and before the wound is closed
* TIR completely avoided irradiation of the heart, lung and oesophagus causing no damage to these structures
* It is currently only available to women taking part in clinical trials
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