An accurate method of 192Ir wire implantation for locally advanced carcinoma of breast

The use of ultrasonography in the localization of the lumpectomy cavity for interstitial brachytherapy of the breast

PURPOSE

To determine the value of breast ultrasonography (US) in defining the lumpectomy cavity for patients treated with interstitial brachytherapy.

METHODS AND MATERIALS

In March 1993, a protocol of low dose rate (LDR) interstitial brachytherapy as the sole radiation modality in selected patients with early breast cancer was initiated at William Beaumont Hospital. To date, 60 patients have been entered in this protocol, and 38 have undergone US assisted placement of interstitial brachytherapy needles. The lumpectomy cavity was outlined in all dimensions and corresponding skin marks were placed for reference at time of implantation. These US dimensions were compared to the physician's clinical estimate of the location of the lumpectomy cavity, the patient's presurgical mammogram, and the position of the surgical scar. In the intraoperative setting, the dimensions of the lumpectomy cavity were also obtained and the placement of the deep plane of interstitial needles was verified by US.

RESULTS

The full extent of the lumpectomy cavity was underestimated by clinical examination (physical exam, operative report, mammographic information and location of the surgical scar) in 33 of 38 patients (87%). The depth to the chest wall was also incorrectly estimated in 34 (90%) patients when compared to US examination. Intraoperatively, US was performed in nine patients and was useful in verifying the accurate placement of the deepest plane of interstitial brachytherapy needles. In 7 of 9 patients (75%), clinical placement of needles did not ensure adequate coverage of the posterior extent of the lumpectomy cavity as visualized by intraoperative US.

CONCLUSIONS

In breast cancer patients considered for interstitial brachytherapy, US appears to be a more accurate means of identifying the full extent of the lumpectomy cavity when compared to clinical estimates. In addition, US allows real-time verification of needle placement in the intraoperative setting.

Method of localization and implantation of the lumpectomy site for high dose rate brachytherapy after conservative surgery for T1 and T2 breast cancer

PURPOSE

This article describes our technique of localization and implantation of the lumpectomy site of patients with T1 and T2 breast cancer. Our method was developed as part of our Phase I/II pilot study of high dose rate (HDR) brachytherapy alone after conservative surgery for early breast cancer.

METHODS AND MATERIALS

In March 1992, we started a pilot study of HDR brachytherapy to the lumpectomy site as the sole radiotherapy after conservative surgery for clinical T1 or T2 invasive breast cancer. Initially, the protocol required intraoperative placement of the interstitial needles at the time of definitive surgery to the breast. The protocol was then generalized to allow the implantation of the lumpectomy site after definitive surgery to the breast, either at the time of subsequent axillary nodal dissection or postoperatively. To date, five patients have been implanted intraoperatively at the time of definitive breast surgery. Twelve patients were implanted after definitive breast surgery, with 7 patients being done at the time of axillary nodal dissection and 5 patients postoperatively. We devised a method of accurately localizing and implanting the lumpectomy site after definitive breast surgery. The method relies on the previous placement of surgical clips by the referring surgeon to mark the lumpectomy site. For each patient, a breast mold is made with radio-opaque angiocatheters taped onto the mold in the supero-inferior direction. A planning CT scan is then obtained through the lumpectomy site. The volume of the lumpectomy site, the number of implant planes necessary, and the orientation of the implants are then determined from the CT scan. The angiocatheters provide a reference grid on the CT films to locate the entry and exit points of the interstitial needles on the plastic mold. The entry and exit points for reference needles are then transferred onto the patient's skin enabling implantation of the lumpectomy site. Needle positions with respect to the lumpectomy site are then verified using simulator radiographs.

RESULTS

Eight double plane implants and four single plane implants have been done using this method. Five implants were done using direct visualization. It has not been necessary to reorient the implant in any of the patients. If not for the presence of surgical clips, the size of the lumpectomy site cannot be separated from the surrounding normal breast tissue.

CONCLUSION

This technique is an accurate way to localize the lumpectomy site for HDR brachytherapy.

Intraoperative Ir-192 implantation for early breast cancer. Techniques and results

Patients with early breast cancer (T1-2 N0-1) can be treated by lumpectomy and irradiation with a local control and survival equal to more radical surgery. Between 1982 and 1988, 323 patients with early breast cancer were treated, when possible, with Ir-192 implants at the time of lumpectomy to a local dose of 2000 cGy in 40-50 hours. Ten to 14 days later, the whole breast was treated to 4500 cGy at 180 per fraction in 5 weeks. The 6-year actuarial survival for stages I and II disease was 98% and 91%, respectively, and the recurrence-free survival was 96% and 98%, respectively. When these 323 patients were evaluated by T status, a local control of 97% was the same for T1 and T2 lesions. The cosmetic results were good to excellent in 95% of the patients. This approach has improved our ability to accurately place the boost dose in the breast.