Background Breast cancer is one of the most common cancers in women. About 30%–85% of breast cancers will metastasize to the bone during the course of the illness. Many studies have shown that molecular marker/subtypes can be useful in determining incidence of different and inconsistent bone metastases. This study aimed to determine the correlation of the risk of bone metastases in breast cancer based on the expression of molecular markers. Methods The research was conducted retrospectively by searching patients' medical record data. The target population of this study was all patients diagnosed with breast cancer who came to our tertiary hospital in the Nuclear Medicine and Molecular Imaging Department from January 2012 to December 2016. Results One hundred and thirty patients (n = 130) were enrolled during the study period with characteristics of sex, age, and immunohistochemical/molecular subtype examination that underwent bone scintigraphy. Mean of age was 50.2 (23–79) years. There were no significant correlations between ER, PR, and HER-2 expressions with bone metastases in breast cancer patients. Ki-67 was showed to be correlated with bone metastases in breast cancer patients in our bivariate analysis. Molecular subtype/markers had no statistically significant correlation with bone metastases in patients with breast cancer. Conclusion Ki-67 with high proliferation index was the most powerful molecular marker to determine the risk of bone metastases. The prevalence of bone metastases in the group with Ki-67 expression with high proliferation (≥20) was 1.8 times greater than the prevalence of bone metastases in the weakest HER-2 group.

Boron neutron capture therapy (BNCT) is a form of cancer therapy based on the interaction of low-energy thermal neutrons and boron-10 (10-B) to produce alpha radiation from He-4 and Li-7 with a high linear energy transfer. A beam of neutrons irradiates a boron drug injected into the tumor, resulting in the boron-injected cancer cells receiving a lethal dose of radiation with the surrounding, healthy cells being minimally affected. Two boron drugs have been used clinically in BNCT, boron sodium captate (BSH) and borophenylalanine (BPA), while a third, pentagamaboronon-0 (PGB-0), is currently under development in the Faculty of Pharmacy of Universitas Gadjah Mada, Indonesia. In Indonesia, there has been a growing interest in the study and use of BNCT to treat cancer, as this method is expected to be safer and more effective than traditional cancer treatment methods.