A simple early soft tissue phase image while performing a routine 99mTc-MDP bone scan can serve the purpose of a screening mammography in early detection of breast cancer

Full text: The role of scintimammography in diagnostic work up of breast cancer is well known. Scintimammography is usually performed with Tc-99m MIBI, Tc-99m Tetrofosmin or Thallium-201. Tc-99m MDP is routinely used for radionuclide bone scanning. It is also an established breast Imaging radiotracer [Sensitivity 92% Specificity 95%, Positive pr. Value 98% and Negative pr. Value 81%]. Scintimammography can easily be performed during bone scintigraphy without injecting any further dose of radiotracer. The patient just needs to be imaged twice. The aim of the study was to find out whether there is any role of Tc-99m MDP scintimammography as a screening procedure, when patients are undergoing bone scanning for any indication. Scintimammography with Tc-99m MDP was performed in 110 patients (age 22 to 76 years), 10 to 20 minutes after injection of 15-20 mCi of the radiotracer. 66 patients had undergone mastectomy for CA breast, 28 were pre-operative or suspected cases of breast CA, 16 patients reported for bone scanning due to indications other than CA breast. All patients were scanned in single rectangular head Gamma Camera (Siemens, Diacom). Three out of 66 post-operative CA Breast patients showed focal radiotracer concentration in the non-operated breast (which was the area of interest) and two of them were found to be malignant. In the pre-operative group of 28 suspected CA breast patients, 2 patients showed focal uptake of radiotracer in the opposite breast, where primary lesion was not suspected clinically. One of them was confirmed to be malignant. On subsequent investigation in the last group of 16 non-breast CA patients, 3 were found to show increased radiotracer uptake, one of which was definite focal concentration. This was proved to be a fibroadenoma. We conclude that single step single injection scintimammography with Tc-99m MDP is extremely useful in detecting occult malignancy / neoplasm and it can be very easily performed during bone scanning without any extra cost. (author)