Ovary: Oral Abstract: Audit on the role and efficacy of PET/CT in recurrent ovarian cancer settings in a tertiary care centre in India
This article was originally published by Wolters Kluwer - Medknow and was migrated to Scientific Scholar after the change of Publisher.
Ovarian cancers tend to recur in 15-70% cases. CA-125 - is a tumor marker used for monitoring therapeutic response, and in surveillance, for recurrent disease. However, it has a limited role as a persistent high level can signify either recurrence or persistence of residual tumor. Metastases from ovarian cancer primarily involve the peritoneum rather than parenchymal sites; thus, the presence of small-volume recurrence or metastatic deposits on the visceral surfaces poses a challenge for interpretation of CT and MR images. PET/CT utilizes its property of higher accumulation in malignant cells to provide both anatomic and functional information for diagnosing malignant tumors.
The objectives of the study were to find the correlation between PET/CT findings and final histopathological diagnosis after a secondary cytoreductive surgery in suspected ovarian cancer recurrences.
Materials and Methods:
PET/CT was done in cases with rising or above normal CA-125 and no radiological findings. These patients with abnormal PET/CT findings were taken up for a secondary cytoreductive surgery and histopathological proven were taken as the standard against which PET/CT positive findings was compared.
The mean age in our group of patients with suspected recurrence was 53 years (Range 39-74 years). Of the 52 patients with suspected recurrence, 40 patietnts with a PET-CT scan with findings suggestive of an avid uptake underwent surgery. 22 patients had serous histology, 12 mucinous and 8 had clear cell carcinoma. Stage-wise distribution at the time of primary surgery is as follows stage I-3, stage II-7, stage III-26, stage IV-4. Of the 40 patients who underwent a second look surgery 32 had histopathologically confirmed recurrence. PET-CT detected a total of 86 lesions in the 40 patients who underwent surgery. Of these, 38 were in the lymph nodes 28 in para-aortic and 10 in pelvic, 32 were peritoneal lesions and 14 were pelvic, 2 were metastatic in the parenchyma of liver. Detection of the lesion on PET-CT was size dependant, of the 9 lesions were missed on PET-CT, 7 were less than 0.5 cm. The mean diameter of the lesions detected was 2.2 cm (range 0.3-6.2 cm). PET-CT accurately identified 62 of 70 histopathologically proven lesions. The overall lesion-based sensitivity of PET-CT is 88.6%, specificity 56.2%, Positive predictive value being 72.1%, negative predictive value of 69.2%. Accuracy of detecting lesions greater than 1 cm is 78.6% (44 of 56 lesions).
Corelation between PET/CT and histopathologicaldisease: k (cohen value) = 0.81 which suggests excellent correlation. For selected patients with ovarian cancer recurrence may benefit from a comprehensive radiographic imaging survey (PET-CT) at the time of even no or minimal CA-125 elevation in early detection and successful cytoreductive surgical resection and an increase in overall survival.