الفهرس | Only 14 pages are availabe for public view |
Abstract Despite performing latest technology in the diagnosis and treatment of ovarian cancer, today it still remains the leadingt cause of death and the fifth most common cancer death in women. The main reason of the low rates of 5 years survival is the recurrence of disease. For this reason imaging modalities has been focused on early detection of the recurrence. Despite adequate treatment and complete response, recurrence is major problem for patients with ovarian cancer. It has been estimated that 60% of patients diagnosed in an advanced stage will develop abdominal relapse mainly owing to metastasis hidden in the peritoneum and to retroperitoneal metastasis .The commonest sites of relapse were with a pelvic mass (48%), peritoneal disease(45%), large or small bowel serosal disease (45%) and nodal disease (33%), most commonly in the paraaortic region. Unusual sites of recurrence included cerebral, liver, pleura, muscle, splenic and biliary deposits. In the pelvis, MRI has been shown to have a 91–93% overall accuracy for differentiating benign from malignant adnexal tumors . The role of MRI in staging ovarian cancer remains a problem-solving modality MRI had good accuracy for diagnosing pelvic and abdominal cancer spread in patients with ovarian cancer, showing 71–87% sensitivity and 44–87% specificity for peritoneal dissemination, and 64% sensitivity and 75% specificity for pelvic and para-aortic LN metastasis. MRI is recommended in patients with contraindications to CT, e.g., to use of contrast agents, in pregnant patients and complementary to inconclusive CT findings. MRI may assist in predicting tumor respectability, particularly in the pelvis. Recently, excellent performance has been reported for MRI in predicting the presence of residual ovarian tumors. 18F-FDG PET imaging for ovarian cancer surveillance has proven useful for detecting early recurrences. Positron emission tomography (PET), particularly when combined with computed tomography (CT), has improved the accuracy of staging ovarian carcinoma. For primary staging of ovarian carcinoma and detection of recurrent ovarian cancer, best performances have been reported with fusion PET/CT, which has higher accuracy than either CT or FD-PET alone. PET/CT devices offer the benefits of both functional and morphological imaging, it is also a useful imaging modality in the detection of recurrence of several cancers and a valuable tool for diagnosing and staging advanced disease and detecting recurrent tumor It has been known 18F-FDG PET/CT is superior than conventional imaging modalities in the restaging of several cancers by distinguishing recurrence from postoperative and postradiation changes and detecting small lymph node metastases. In several studies, the sensitivity and specificity of 18FFDG PET/CT in the detection of ovarian cancer recurrence have been reported as 83-95% and 71-100%, respectively. However, due to the limited ability of PET/CT to depict microscopic or small-volume peritoneal lesions, in cases with a peritoneal lesion or a subtle peritoneal tumor, MRI has been shown to be sensitive.Therefore, although MRI has some limitations for detecting microscopic or small-volume lesions, MRI is likely to be more helpful at depicting microscopic or small-volume lesions than PET/CT.. |