Presentation on theme: "TARGeted Intra-operative radioTherapy (TARGIT) for breast cancer - a randomised trial Jayant Vaidya, Michael Baum, Jeff Tobias, Joan Houghton,Mo Keshtgar,"— Presentation transcript:
TARGeted Intra-operative radioTherapy (TARGIT) for breast cancer - a randomised trial Jayant Vaidya, Michael Baum, Jeff Tobias, Joan Houghton,Mo Keshtgar, Irving Taylor, Richard Sainsbury, Derek DSouza, S Morgan, M Metaxas, K Harte, A Sliski, E Thomson
Local treatment of breast cancer Have the principles really changed? Halsteds Radical Mastectomy Limited Surgery plus Radical Radiotherapy
Radiotherapy typically takes 6wks to deliver Patients dont like these 30 daily visits Geography prevents many women from receiving conservative breast surgery Breast cancer = 1/3rd of RT work-load Long waiting lists in many centres Are there any problems with current approach?
The Solution A novel radiotherapy technique that will accurately deliver all the necessary radiotherapy in ONE sitting Treat only the index quadrant of breast
The Rationale Whole organ analysis of mastectomy specimens* 3-D analysis 63% harbour occult cancer 80% of these are in other quadrants * Vaidya et al, Br. J. Cancer; 1996
The Rationale but, in trials of conservative surgery: > 90% recurrences occur in the index quadrant - whether radiotherapy is given or not The occult cancers in other quadrants of the breast are probably not the cause of local recurrence. Radiation to the index quadrant alone might be sufficient
Targeted Intra-operative Radiotherapy: (Targit) A Novel Approach
The Technique PRS400 (Intrabeam) A miniature electron generator and accelerator Accurately delivers radiotherapy from within the breast in about 25 minutes.
20 Gy at 2mm 1 Gy at 27mm Soft X-rays Small very-high-dose region Quick attenuation (1/r3)- – distance protects normal tissues Shielding is easy Physical radiation dose
Applicator is inserted and purse string is tied
Rather than the complicated conformation of the source to the target... the target - the pliable breast tissue - is conformed to the source
Targit with PRS Estimated Biologically equivalent radiation dose (BED) 2mm e.g. breast 12 Gy 53 Gy 10mm e.g. skin 12 Gy 7 Gy Distance from applicator External Boost / =10 / = Gy 21 Gy
1. 1.To test the the TARGIT technique -its feasibility and safety 2. To test the approach of treating only the index quadrant
Early operable breast cancer: <4cm in size Phase I/II study July 1998-Jan 2000 Wide Local excision + axillary surgery Boost radiation with Photon Radio Surgery (PRS) intra-operatively Whole breast radiotherapy post-op
Results – the pilot study 25 patients treated With tumours ranging from cm No major complications No recurrences Median follow up 30 m Cosmetic results are good
Complications Our 3 rd patient had radionecrosis of skin near the scar- skin was too close to the applicator 9 months 28 months
Cosmetic Results 1) 1)Photographs 2) 2)Patients own assessment of the cosmetic result – appearance and texture: a) a)What would be your expected score (out of 10)? b) b)What is the actual score (out of 10) Satisfaction index = Actual / Expected
Cosmetic Results Satisfaction index (observed/expected) Mean95% CI Appearance1.2( ) Texture1.2( ) In only 4 out of the 25 patients in the pilot study, was the observed less than expected.
Breast cancer - breast conserving therapy Randomisation Study ArmControl Arm Wide local excision of primary tumour + SNB/ axillary dissection + Targeted Intraoperative Radiotherapy (If histopathology is Lobular or EIC, add 5wks of postoperative radiotherapy) Wide local excision of primary tumour + SNB/ axillary dissection + 6 wks of Postoperative Radiotherapy
1st patient randomised on 29 March patients randomised until June 2001 No complications in the IORT arm 1 wound infection in the post-op RT arm Cosmetic appearance is good No recurrences to date Median follow up is 15 months
If proven, Targit could Save up to 1/3rd of the workload of radiotherapy units world-wide Allow women from remote areas to avail of breast conserving therapy
The cost of delivering Targit is about half that of a 6 week course of radiotherapy Assuming that 60% of patients have conservative therapy, it could save £15,500,000 pa in the UK Worldwide, it could save thousand of women from losing their breasts!
Site of Local Recurrence after BCT Authorn%in index q. Clark RM, % Schnidt SJ, % Boyages J, % Kurtz, JM, % Fisher B, % Veronesi U, % TOTAL577091%
GG Ribeiro, B Magee, R Swindell, M Harris and SS Banerjee Clin Oncol (R Coll Radiol) 1993;5: The Christie Hospital Trial b) Wide Field (WF): 4 Gy (21 days) whole breast, axilla & scf 708 patients randomised a) Limited Field (LF): 4 Gy (10 days) 8x6 cm area 10MeV to a depth of 2.5cm
The Christie Hospital Trial 8 Year Results Breast Recurrence: LFWF Duct Carcinoma(n=534)15%11% EIC (<25% invasive, (n=45)21%14% Lobular Carcinoma (n=95)34%8%