Detection Of Locoregional Metastases Research Articles

Multimodale molekulare Bildgebung des Prostatakarzinoms – aktueller Stand

Prostate carcinoma is the most common life-threatening cancer affecting men in the western world. In Germany about 40 600 new cases have to be expected each year. The mortality is around 10%. The major goals of pretherapeutic imaging are to determine the local extent of prostate carcinoma in terms of intraprostate localisation, extracapsular extension (ECE), seminal vesicle invasion (SVI), tumour infiltration into neurovascular bundles, and if this has taken place, into surrounding tissues and organs in the small pelvis, detection of loco-regional metastases via the lymph nodes and if this so, of distant metastases. Exact pretherapeutic diagnosis and staging are essential, because the tumour treatment must be selected in strict dependence on clinical tumour stage and risk profile. Both anatomic and functional molecular imaging of prostate carcinoma have advanced significantly in recent years. When there are problems with diagnosis, e.g. when prostate punch biopsies are negative while the suspicion of prostate carcinoma persists, C-11/F-18 choline PET/CT and MRI/MRS may be helpful in localising the carcinoma, revealing how the carcinoma relates to the surrounding intra- and extraprostatic structures and organs, and making a targeted repeat biopsy possible. Lymphotropic contrast agents are highly promising for accurate nodal staging of prostate carcinoma, but are not yet available for routine clinical use. In these circumstances, the sensitivity of nodal staging with the widely available imaging modalities remains difficult. There has been particularly substantial progress in the localisation of local relapse, which can be imaged with contrast-enhanced C-11-choline PET/CT and MRI in most cases when PSA is considerably below 1 ng/ml. F-18-fluoride PET/CT has proved accurate in the diagnosis of skeletal metastases from prostate carcinoma.

Role of positron emission tomography in the (re-)staging of oesophageal cancer

Background. Various studies have demonstrated that 18F-Fluorodeoxyglucose-positron emission tomography (FDG-PET), measuring altered tissue glucose metabolism, is a promising non-invasive method for detecting both distant nodal and haematogenous metastases in patients with oesophageal carcinoma (OC) and might thus prevent futile oesophagectomies. Moreover, FDG-PET is a promising tool in assessing response to non-surgical treatment, and might therefore be used for an early decision on whether treatment should be stopped or continued. Material and methods. Review of the recent literature regarding the diagnostic performance of FDG-PET in the preoperative staging of patients with OC and regarding diagnostic accuracy of FDG-PET in assessing response to neoadjuvant therapy in patients with OC compared to conventional techniques (especially computed tomography (CT) and endoscopic ultrasonography (EUS)). Results. A search of the literature resulted in the inclusion of 16 studies on the diagnostic value of FDG-PET. Sensitivity and specificity for the detection of locoregional metastases were moderate. Sensitivity and specificity were reasonable for distant metastases. The diagnostic accuracy of FDG-PET in assessing response to treatment was similar to the accuracy of EUS, but significantly higher than that of CT. Conclusions. The staging value of FDG-PET in OC patients is limited in the detection of locoregional metastases; however; its value is higher in the detection of distant lymphatic and haematogenous metastases. Moreover, FDG-PET is a valuable tool for the non-invasive assessment of histopathologic tumour response after neoadjuvant therapy.