Current role of bone scan with phosphonates in the follow-up of breast cancer

Abstract

Bone scintigraphy with radiolabelled phosphonates shows a high sensitivity in detecting breast cancer metastases. For this reason it has been considered the most useful tool for early diagnosing and monitoring the metastatic spread of breast cancer. In the past years, there has been wide debate on its impact on survival time, morbidity and quality of life. The results of some studies on the asymptomatic patients during follow-up have led to the adoption of an almost minimalist policy for breast cancer surveillance including only a few procedures (breast self-examination, history, physical examination, patient education on symptoms, and abdomen ultrasonography). The routine use of additional tests, such as tumour markers, chest X-rays, bone scintigraphy, and computed tomography (CT), has not been recommended, except in those cases with clinical suspicion or in patients at high risk of metastases. On the other hand, the early diagnosis of bone involvement may reduce the risk of skeletal-related events, thus leading to a significant improvement in quality of life and opening the options of the new therapy choices in order to plan more aggressive systemic treatments whose efficacy could have impact even on survival. Besides this, the recent development of nuclear medicine modalities, the evolution of PET and PET/CT systems has brought new elements of discussion in this area, since at present the depiction of skeletal metastases can be carried out with 99mTcphosphonates and also with 18F-PET, 18F-FDG-PET, and 18F-FDG-PET/CT. Therefore, the clinical problem today is not only when and whether bone scans should be used, but the question has also become which diagnostic modality can be used? In our opinion the choice of the modality has to consider different general and local factors such as the diagnostic accuracy, the availability, the economic costs, and so on. The most important issue is that every new diagnostic approach should be validated by large randomised prospective clinical trials with the goal to measure the effective impact on the course of the disease and on patient management. Nowadays, we do not have a sufficient amount of this kind of data, in spite of much clinical evidence that demonstrates the excellent sensitivity of bone scintigraphy in discovering skeletal metastases. © 2008 Springer-Verlag Berlin Heidelberg.