Lymphoscintigraphy in staging and management of breast cancer

Internal mammary lymphoscintigraphy (IML) is a simple non-invasive and reproducible technique to determine the extent of the parasternal node invasion in patients suffering from breast cancer. A total forty four patients--37 before surgery or any sort of treatment and seven patients after having undergone surgery, chemotherapy and/or radiotherapy were included in this study to assess the potential role of lymphoscintigraphy in the context of the present 'state of the art' of staging and management of breast cancer patients in Bangladesh. The scintigraphic test was done using Technetium 99m (Tc-99m) Antimony sulfide colloid in a dose of 500 microCi injected interstitially into the sub-costal space. Images were obtained after two to three hours on a Gamma Camera and the study findings were then interpreted as normal, abnormal and equivocal. The scintigraphic images obtained in patients who had undergone surgery, chemotherapy and/or radiotherapy were difficult and more challenging to interpret than those images obtained from patients before surgery or other therapy. This was evidenced by the high number (71%) equivocal cases of IML findings in patients after treatment as compared to only 22% equivocal cases in patients studied before surgery or other therapy. Parasternal lymph node involvement was found to occur regardless of the site or size of the primary tumour. Thirty three percent of tumours located in the outer quadrant showed abnormal nodes on IML. When the size was considered, IML was found abnormal in 22.20% patients with tumour size less than 2 cm in diameter. Correlation of IML with clinically palpable lymph nodes showed abnormal scan findings in 18% patients without clinically demonstrable axillary lymph nodes. These findings are in agreement with previously published data and suggests that conventionally classified stage I patients may in effect be in stage II or even in stage III of the disease. In conclusion, when the technique of lymphoscintigraphy is done with a comprehensive overview of the patient, and when the interstitial injection site is correct, it will generally lead to a logical and clinically useful interpretation of the data for more efficient management of the patient with breast cancer.