Internal mammary lymphoscintigraphy: current status in the treatment of breast cancer

Contralateral internal mammary node invasion in breast cancer: lymphoscintigraphic data

Contralateral internal mammary (IM) node invasion has been analyzed in 1025 patients where the two IM chains have been investigated by lymphoscintigraphy. Contralateral IM lymphoscintigrams (LySc) were classified as abnormal (nodes involved by metastatic cancer) in 153 cases (or 15.6% of the population) and this included one-third of the cases with homolateral IMLySc abnormalities (114/318). Overall, patients with bilateral abnormalities on IMLySc (Grp A) had a similar survival to those with homolateral abnormal IMLySc (Grp B). However, when other prognostic variables were taken into account and two matched groups were obtained, patients with bilateral internal mammary node involvement had a highest incidence of clinically evident systemic metastatic disease than patients with homolateral IM involvement. Contralateral IM nodes are invaded in one-third of the cases with homolateral IM node invasion. These patients may have a prognosis worse than those with only homolateral IM disease.

Optimizing radiotherapy of the internal mammary chain in breast carcinoma by scintigraphy

BACKGROUND AND PURPOSE

The reduction in breast cancer death, as reported in recent trials, was found to be significant and techniques of minimizing cardiac dose were found to be important. The purpose of our study was to investigate the location of the internal mammary chain (IMC) both in the lateral and dorsal direction, in primary breast cancer patients.

MATERIAL AND METHODS

In 320 female breast cancer patients a scintigram of the IMC (IMC-s) was performed. Lateralisation and depth were determined. Special attention was paid to the consequences of the use of fixed target volumes.

RESULTS

Lateralisation was determined in 281 patients, with a mean of 33.9 mm. Depth was determined in 266 patients, with a mean of 31.0 mm. We showed, that the location of the IMC lymph nodes varies considerably, both in the lateral and in the dorsal direction. The maximum values of the lateralisation and the corresponding depth did not correlate. Using electron beam therapy, a fixed target volume defined by a (ipsi)lateralisation of 50 mm and a dose specification on a depth of 30 mm was demonstrated to include the IMC adequately, in 12% of all cases.

CONCLUSIONS

The use of fixed target volumes in the radiotherapy of the IMC in breast cancer patients is inappropriate. We recommend performing an IMC-s, in treatment position, with appropriate adjustment of the target volume.

Staging for breast carcinoma

Pretreatment staging and posttreatment follow-up of the breast cancer patient consists of physical examination of the breasts and regional node-bearing areas, routine laboratory studies, chest radiography, and bilateral mammography. For palpable tumors, mammography is used to determine tumor size and to identify nonpalpable multifocal or contralateral lesions. Mammography is an important adjunct to physical examination when monitoring for local recurrence in the irradiated breast or when searching for second primary cancers in the contralateral breast. Axillary nodes are evaluated by direct palpation, but some investigators recommend lymphoscintigraphy to examine the internal mammary chain. The most common sites for distant metastases are the skeleton, lung, brain, and liver. Although radionuclide scanning is currently the most effective method to evaluate metastases to bone, plain radiography, and sometimes computed tomography and magnetic resonance imaging, are required to corroborate radionuclide findings. However, due to cost constraints and anticipated low yield, routine imaging for metastases should be limited to chest radiography.