Recurrent prostate cancer and metastatic disease

Abstract

Recurrent prostate cancer can be found in 20-50% of patients after radical prostatectomy within 10 years following primary treatment and up to 53% within 10 years post 3D conformal radiation therapy. About 50% of the patients develop local recurrence while the others develop metastatic disease with or without local recurrence. In most cases, recurrence will be diagnosed by raising PSA levels, which is a sensitive biomarker for recurrence; however, it does not allow differentiation between local, regional, and systemic disease. A lot of PET tracers have been used in imaging prostate cancer based on increased glycolysis ([18F]FDG), fatty acid synthesis ([11C]acetate), amino acid transport and protein synthesis ([11C]methionine), androgen-receptor expression ([18F]FDHT), osteoblastic activity ([18F]fluoride) as well as cell membrane proliferation by radiolabeled phospholipids ([11C]- and of [18F]choline). Among these radioactively labeled choline derivates are most commonly used. PET and PET/CT using [11C]- and [18F]-labeled choline derivates is a promising imaging modality for imaging recurrent and advanced prostate cancer which is increasingly being used. Its value in restaging prostate cancer has been analyzed in numerous studies. The detection rate of PET and PET/CT using [11C]- and [18F]-labeled choline derivates in patients with biochemical recurrence for local, regional, and distant recurrence shows a linear correlation with PSA value at the time of imaging. At PSA levels below 1 ng/mL, diagnosis of recurrence is possible in 20-30% of the patients and reaches about 75% in patients with a serum PSA value > 3 ng/mL. Additionally, it has been shown that the detection rate of [11C]choline PET/CT is closely related to PSA doubling time which is an additional independent predictor of choline PET/CT positivity. PET/CT - in comparison to PET - especially improves the lesion localization as well as characterization of lymph node metastasis and bone metastases. Bone is the second most common site of metastatic disease after lymph nodes in prostate cancer. The occurrence of bone metastases is related to a poor prognosis and is one of the major causes of morbidity and mortality in patients with advanced prostate cancer. Therefore, early detection of metastatic bone disease and its extent is crucial for staging, restaging, and treatment. Since an early diagnosis of recurrent prostate cancer and the exact localization of the site of recurrence (local recurrence, lymph nodal involvement, or systemic recurrence including bone metastases) have a direct influence on therapeutic strategy, PET and PET/CT with [11C]- and [18F]choline derivates can be helpful in the clinical setting with respect to disease management and individualized therapy strategies. This chapter focuses on the use of PET and PET/CT with [11C]- and [18F]-labeled choline derivates in imaging prostate cancer with special emphasis on patients with recurrent prostate cancer and metastatic disease.