ABSTRACT
BACKGROUND: The precise role of total body (18) F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) in the clinical management of patients with cutaneous malignant melanoma (CMM) is not well established. OBJECTIVE: The purpose of this study was to investigate the diagnostic accuracy of PET/CT in early- and late-stage patients with high-risk CMM. METHODS: We retrospectively analysed various imaging, histopathological and clinical data from 97 patients also examined by PET/CT during a 5-year period (2007-2011). Three groups were assessed: stage I/II, resected stage III and unresectable stage III/stage IV. RESULTS: The median follow-up time of living patients was 43.48 ± 19.67 (15-142) months. We observed a high diagnostic accuracy in all stages (91.3%, 92.5% and 96.2% respectively). PET/CT appeared to be reliable diagnostic tool even for the detection of small lymph node metastases. PET/CT was informative in 14 of 19 cases wherein another imaging examination provided inconclusive results regarding lesion dignity. However, PET/CT was less suitable for properly evaluating the dignity of a lung lesion. A true positive scan was twice as likely in clinically negative patients with resected stage III disease than in patients with stage I/II disease (35.9% and 14.5%, P = 0.007). CONCLUSIONS: These results confirm that PET/CT is an important diagnostic tool in the management of patients with high-risk CMM, but it cannot replace the standard of care examinations. More accurate clinicopathological and timing criteria must be defined to best utilize the advantages of this imaging method.
Subject(s)
Melanoma/diagnostic imaging , Melanoma/secondary , Positron-Emission Tomography , Skin Neoplasms/diagnostic imaging , Tomography, X-Ray Computed , Adult , Aged , Aged, 80 and over , False Negative Reactions , False Positive Reactions , Female , Fluorodeoxyglucose F18 , Humans , Lymphatic Metastasis , Male , Melanoma/pathology , Middle Aged , Multimodal Imaging , Neoplasm Staging , Radiopharmaceuticals , Retrospective Studies , Risk Factors , Sensitivity and Specificity , Skin Neoplasms/pathology , Young AdultABSTRACT
OBJECTIVE: To define whether volume of water, administered during water enema CT (WE-CT) for local staging of rectal cancer, may be reduced without compromising the diagnostic value of the examination. MATERIALS AND METHODS: 29 patients with rectum cancer underwent preoperative WE-CT. Contrast-enhanced CT (equilibrium phase) measurements were performed after i.v. injection of smooth muscle relaxant and rectal administration of 400-500 ml lukewarm tap water. Quality of the obtained scans was evaluated and the images were analyzed for depth of tumor invasion. Results of the CT examinations were compared to findings at surgery. RESULTS: Despite reduced dose of water enema, 19/29 examinations were of excellent quality, 6/29 good, and 4/29 poor, but still diagnostic. We achieved sensitivity (90.1), specificity (70.1) and accuracy (86.2) in differentiating tumors confined to the bowel wall from those extending beyond it. CONCLUSION: Large volume of water enema administered during CT examination of the rectum may cause complaints and increases the risk of complications. Our results prove that using lower amount of water does not impair the quality of examination and accuracy of local staging of rectum carcinomas.