19 Breast Cancer

450 Breast Cancer

component, only 2% had residual disease beyond a 2 cm margin. In a similar study by Gump (15), excluding invasive lobular and EIC positive patients, residual tumour was found in only 12% beyond a 2 cm margin in tumours less than 2 cm.

The early results in unselected patients were however not encouraging. Local recurrence rates of 15- 37% with a follow up from 1.5 to 8 years have been noted (9). However, there is some indication that this approach might be of value in strictly selected low risk patients over 50 years old, low or moderate grade, T1-T2 with negative section margins and no presence of an extensive component of intraductal carcinoma. (Table 18.3). Initial findings of these trials are promising with local recurrence rates of 0.45% per year of follow up in the first years, which is comparable to local recurrence rates after BCS and whole breast irradiation in low and moderate risk patients. However, longer follow up and careful assessment in phase III trials is needed before this could be considered as a routine treatment in patients with a low or moderate risk for local recurrence. Table 18.3: Local failure rates after Brachytherapy alone as sole treatment modality after breast conserving surgery in selected patients. Review of the literature. Institute Selection BT type n Median Follow-up Local failure LF per year William Beaumont Hospital (59) <3cm,N0 N1bi SM clear >2mm LDR/HDR 50/32- 34Gy 133 3.2 y 0% 0% Ochsner Clinic USA (26) <4cm , N0 N1bi SM clear LDR/HDR 45/32- 34Gy 150 3.8 y 1.3 % 0.3% London Reg. C.C. Canada (33) <4;5cm N0-1 SM clear HDR 37.2 Gy 39 1.7 y 2.6% 1.5% Örebro Medical Center (25) < 5cm N0-1 SM clear PDR 50 Gy 43 2.8 y 2.3% 0.8% NIO Budapest (36) <2 cm N0-1a HDR 30.3-36.4 87 2.8 y 2.3% 0.8%

452

1.3 %

0.45%

Total :

11 References

1. Bartelink H, Borger JH, Van Dongen, et al. The impact of tumour size and histology on local control after breast conserving therapy. Radiother Oncol 1988; 11 : 297-304.