The Role of Positron Emission Tomography - Computed Tomography (PET - CT) Scan in the Assessment and Management of Carcinoma of the Prostate Gland: A Review and Update

Background: PET CT Scan has been used on numerous occasions in the assessment and management of various malignancies but it is only occasionally used in the assessment management of carcinoma of the prostate gland globally. There is the need to establish whether or not PET/CT scan is a useful imaging technique which should be used more often in the investigation of biochemical failure following treatment of carcinoma of prostate gland with curative intent Aim: To investigate the suggestion that PET/CT scan would be a useful and reliable imaging option for the investigation of biochemical recurrence resulting following the treatment of prostate cancer with curative intent by reviewing the literature relating to the use of PET / CT scan in carcinoma of the prostate gland. Method: Various internet data bases were searched including: Google, Google Scholar, Yahoo, and PUBMED. The search words that were used included: PET/CT Scan in carcinoma of the prostate, PET/CT scan in prostate cancer, PET/CT scan and prostate cancer, PET/CT scan and carcinoma of the prostate. Results: Fifty two manuscripts that have been published relating to the use of a form of PET/CT scan in relationship to investigation of carcinoma of the prostate gland were utilized to write the article. One of the articles published in Dutch was a review article. Another paper reported the use of PET CT scan in the diagnosis of Hurtle tumour (a benign tumour) in association with carcinoma of the prostate gland. The remaining manuscripts contained case reports and studies regarding the use of various types of PET/CT scan in the investigation of biochemical failure as well as in the treatment and follow-up of some cases of metastasis. On the whole almost all of the papers had confirmed the high sensitivity and high specificity of PET/CT scan in detecting localized and distant metastatic lesions in the scenario of slight elevations of serum PSA. There have been reports of PET/CT scan being able to detect localized and distant metastasis when conventional computed tomography scan and isotope bone scan failed to detect metastases. In one case when the serum PSA level was high isotope bone scan and CT scan failed to detect bone metastases but PET/CT scan detected bone metastases. Conclusions: PET/CT Scan is a very useful imaging modality that detects localized and distant metastases in biochemical recurrence of prostate cancer and this modality of imaging should be used more often from now onwards. CT scan would usually detect nodes/lesions that measure 1 cm or larger but PET/CT scan would detect smaller sized lesions at slightly raised levels of serum PSA. The detection of small localized metastasis at a slightly elevated serum PSA values would make it easier for the undertaking of a second-line treatment of curative intent in the form of salvage lymphadenectomy or salvage radiotherapy targeted at the lesion. Perhaps PET/CT scan should be the first-line imaging modality which should be used in investigating biochemical recurrence and this should be done when the serum PSA is slightly elevated.