Determination and clinical features of bone pseudoprogression in metastatic breast cancer

Osteoblastic new lesions detected using CT (bone window) may be considered bone pseudoprogression, which predominantly occurs in the early stages of treatment. ALP serves as a biomarker for differentiating pseudoprogression from disease progression on CT (bone window) in patients with bone metastasis. Clinicians should exercise caution regarding the appearance of new osteoblastic lesions in patients not exhibiting extraosseous disease progression or progressive lysis on bone lesions.