“The most important benefit of TARGIT for a woman with breast cancer is that it allows her to complete her entire local treatment [lumpectomy and radiation therapy] at the time of her operation, with lower toxicity.”
- The TARGIT technique uses the Intrabeam device for delivering precise and timely dose of intraoperative radiotherapy accurately to the tumour bed.
- An academic insight led to the development of this device through a collaborative effort between University College London and the Photoelectron Corporation in 1990s.
- It was first used on 2 July 1998 in the Middlesex Hospital, UCL, London. Intrabeam is currently manufactured by Carl Zeiss
Plain English Summary of the TARGIT-A trial
- About 70% of patients with breast cancer are eligible for breast-conserving surgery (a lumpectomy), after which the remaining breast is treated with radiotherapy; this avoids a full mastectomy.
- Traditionally, external beam radiotherapy (EBRT) is delivered to the entire breast in small doses every day for 3– 6 weeks, necessitating patients to travel to and from the radiotherapy centre every working day. This can be impractical and strenuous.
- The TARGIT (TARGeted Intraoperative radioTherapy) procedure precisely delivers radiation in a single dose during the lumpectomy operation over 15– 35 minutes, using a ball-shaped device that is placed in the space where the tumour was. This way, unnecessary potentially harmful radiation to healthy tissues (skin, heart, lungs, etc.) is avoided and the areas nearest to the tumour site receive the most radiation. In this way, four-fifths of patients avoid EBRT altogether.
- The TARGIT-A (TARGeted Intraoperative radioTherapy Alone) trial compared TARGIT with EBRT in 3451 patients who were aged≥ 45 years and found that, when TARGIT is given with lumpectomy, the control of breast cancer is much the same as with EBRT. The chances of being alive without return of cancer in the breast at 5 years were 93.9% with TARGIT during lumpectomy and 92.5% with EBRT. Compared with EBRT, TARGIT had fewer side effects and fewer deaths from heart attacks or other cancers. TARGIT would be less expensive than EBRT, potentially saving the NHS up to £9.1 million a year, without considering the cost savings to patients.
- Targeted intraoperative radiotherapy during lumpectomy is an effective, safer and less expensive option for eligible patients.
What was done in the TARGIT-A trial?
- The TARGIT-A trial was a randomised trial testing an individualised approach of radiation after lumpectomy for breast cancer.
- The comparison in the TARGIT-A trial was between standard radiation therapy that is given over several weeks after a lumpectomy vs. a risk-adapted approach using single dose of TARGeted Intraoperative radioTherapy (TARGIT) using Intrabeam given at the time of lumpectomy.
- The risk-adapted protocol recommended that if the patients who had received TARGIT IORT with Intrabeam were found to have high risk factors postoperatively, they also received whole breast radiation – which occurred in 15-20% of cases as expected in the protocol; otherwise, about 80% of such patients completed their treatment (surgery and radiation) during their lumpectomy.
- The pre-specified non-inferiority margin was an absolute difference in local recurrence of breast cancer between TARGIT and EBRT of 2.5% — in simple terms, if the absolute difference in local recurrence between the two treatments being compared was less than 2.5%, they would be considered non-inferior to each other in terms of local control of breast cancer. Patient preference studies have suggests majority of patients consider such a 2.5% margin as appropriate.
- 3451 patients from 33 centres in 11 countries participated in the TARGIT-A trial (UK, USA, Germany, Italy, France Poland , Switzerland, Norway, Denmark, Canada and Australia) from 24 March 2000 to 25 June 2012. (map).
TARGIT-A Trial Design
In the randomised TARGIT-A trial, two policies of local radiation treatment are compared:
Eligible patients were recruited at either of the two stages of their treatment in the pragmatic Targit trial:
Before the primary surgery (Prepathology randomisation)
This is the original method of entry into the TARGIT-A trial for a breast cancer patient. Once the decision to do a wide local excision (lumpectomy) is taken, and informed consent obtained, the randomisation takes place before surgery and if randomised to TARGIT, it is delivered to the fresh tumour bed immediately after lumpectomy for breast cancer. If at the postoperative pathology review, it is felt that they have a particularly high risk of local recurrence especially in other quadrants ( EIC, invasive lobular carcinoma or positive excision margins) then external beam radiotherapy can be added- all as part of the experimental arm of the trial. Centres could pre-specify additional such factors such as extensive lymphovascular invasion, multiple positive nodes, etc.
After the primary surgery (Postpathology randomisation)
This mode of entry into the trial was added to enable patients in whom the excision of the cancer had already been performed. This was logistically easier in some centres and theoretically allowed better case selection – although it required a second procedure to be performed. Randomisation in the Targit-A trial is performed after the the primary cancer is removed and if allocated to receive TARGIT, single session intraoperative radiotherapy is given as a day-case operation .
What was found? Results of the TARGIT-A trial
- When TARGIT is given with lumpectomy, the 5-year local recurrence of breast cancer is similar to EBRT
- When TARGIT is given as a second procedure, the difference in local recurrence between TARGIT and EBRT was more than 2.5%
- Breast cancer mortality with TARGIT were similar to EBRT
- Mortality from other causes was significantly lower with TARGIT due to fewer deaths from cardiovascular causes and other cancers.
- The results remain stable with longer follow up. The results were the same for the large number (1222) patients who were treated between 2000-2008 and had a median follow up of 5 years.
Is the follow up of the TARGIT-A trial long enough?
- Although breast cancer can continue to recur beyond 5 years, the peak hazard is in the first 2-3 years. More importantly, the beneficial effect of radiotherapy on local recurrence is mostly in the first 2-3 years with no further benefit beyond the first 5 years after surgery.
- Thus, for local recurrence in radiotherapy trials, the 5-year results are indicative of longer term results.
- The TARGIT-A trial has a large number of patients (n=1222) with a median follow up of 5 years and even larger 2232 with a median follow up of nearly 4 years.
- Therefore, these results can be relied upon to guide the application of TARGIT using Intrabeam in routine clinical practice in appropriate patients. For a more detailed explanation see Why is the follow up duration in TARGIT-A trial adequate?. PDF
TARGIT IORT with Intrabeam for breast cancer vs. several weeks of radiotherapy
Better breast-related quality of life with Intrabeam TARGIT-IORT compared with EBRT – data from a sub-study of the TARGIT-A trial
Partial Breast Irradiation with TARGIT IORT A letter in the Lancet showing how the meta-analysis of the GEC-ESTRO and the TARGIT-A trial results provide further support for Partial Breast Irradiation
BMJ Open: TARGIT IORT radiotherapy during lumpectomy for breast cancer could save millions of travel miles & tonnes of CO2. …plus free up thousands of hours for women with early stage breast cancer, every year.
Video Abstract: https://www.youtube.com/watch?v=uJr4YzZA21k
Press release by the BMJ
Reduced mortality with targeted radioterapy for early breast cancer – a meta- analysis of randomised trials: an undeniable benefit to patients
The TARGIT trial office has received its main funding from the Health Technology Assessment programme of the National Institutes of Health Research, Department of Health, UK for the TARGIT-A and TARGIT-B trials
First publication of the main results (2010)
Vaidya JS, Joseph DJ, Tobias JS, Bulsara M, Wenz F, Saunders C, Alvarado M, Flyger HL, Massarut S, Eiermann W, Keshtgar M, Dewar J, Kraus-Tiefenbacher U, Sutterlin M, Esserman L, Holtveg HM, Roncadin M, Pigorsch S, Metaxas M, Falzon M, Matthews A, Corica T, Williams NR, Baum M. Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): an international, prospective, randomised, non-inferiority phase 3 trial. The Lancet. 2010 ;376(9735):91-102.
5-year results and first analysis of survival (2013)
Vaidya JS, Wenz F, Bulsara M, Tobias JS, Joseph DJ, Keshtgar M, Flyger HL, Massarut S, Alvarado M, Saunders C, Eiermann W, Metaxas M, Sperk E, Sütterlin M, Brown D, Esserman L, Roncadin M, Thompson A, Dewar JA, Holtveg HMR, Pigorsch S, Falzon M, Harris E, Matthews A, Brew-Graves C, Potyka I, Corica T, Williams NR, Baum M. Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer: 5-year results for local control and overall survival from the TARGIT-A randomised trial. The Lancet. 11 November 2013. doi:10.1016/s0140-6736(13)61950-9 Full text PDF Podcast
Full final 226 page report of the TARGIT-A trial for the the National Institutes of Health Research, Department of Health, UK (2016)
Vaidya JS, Wenz F, Bulsara M, Tobias JS, Joseph DJ, Saunders C, Brew-Graves C, Potyka I, Morris S, Vaidya HJ, Williams NR, Baum M. An international randomised controlled trial to compare TARGeted Intraoperative radioTherapy (TARGIT) with conventional postoperative radiotherapy after breast-conserving surgery for women with early-stage breast cancer (the TARGIT-A trial). Health Technology Assessment 2016;20(73) TARGIT-A randomised clinical trial of TARGIT IORT using Intrabeam