Prostate cancer : the use of PSA and imaging for staging assessment

Abstract

This dissertation was performed to assess the role of Prostate Specific Antigen (PSA) and imaging modalities in staging prostate cancer. Through this study, it was found that PSA is not always accurate in detecting and staging prostate cancer since a high PSA value can be a result of several conditions other than prostate cancer such as benign prostatic hyperplasia and prostatis. Certain medications can also have an effect on PSA since these can either suppress or elevate the value of PSA. It was also established that low PSA does not necessarily exclude the presence of prostate cancer, since this can arise from hormonal therapy used to treat prostate cancer, or due to surgery of the prostate. An analysis of the medical history of the patient aids to determine whether further assessment through the use of imaging modalities is necessary. During the course of this study, it was determined that at St. Luke's Hospital, CT and bone scan are the main imaging modalities used for staging prostate cancer. These two imaging modalities are considered as the gold standard for assessing lymph node and bone metastasis respectively. It was also established that when bone scan is not conclusive, plain X-rays are used to exclude or demonstrate bone metastasis. Through the literature review it was revealed that a CT examination should be performed when the PSA value is above 20ng/ml, while bone scan should ideally be carried out on patients with PSA above 1 Ong/ml. On the basis of the findings, recommendations are proposed on how various imaging modalities and other tests such as digital rectal examination and biopsy can be utilised to achieve the best staging assessment.