Thin-section CT follow-up of metastatic ovarian carcinoma correlation with levels of CA-125 marker and clinical history

Impact of FDG PET in optimizing patient selection for cytoreductive surgery in recurrent ovarian cancer

PURPOSE

To investigate the impact of PET and PET/CT scanning on decision-making in management planning and to identify the optimal setting for selecting candidates for surgery in suspicious recurrent ovarian cancer.

METHODS

A retrospective chart review was performed in patients with possible recurrent ovarian cancer after primary optimal cytoreduction and taxane/carboplatin chemotherapy who had undergone FDG PET or FDG PET/CT scans from July 2002 to August 2008 to help make treatment decisions. The analysis included 44 patients who had undergone a total of 89 PET scans. The positive PET scans were classified as follows. (1) localized (one or two localized sites of FDG uptake), (2) multiple (three or more sites of FDG uptake), (3) diffuse (extensive low-grade activity outlining serosal and peritoneal surfaces).

RESULTS

Of the 89 PET scans, 52 (58.4%) led to a change in management plan. The total number of patients in whom cytoreductive surgery was selected as the treatment of choice increased from 12 to 35. Miliary disseminated disease, which was not detected by PET scan, was found in 22.2% of those receiving surgery. Miliary disseminated disease was detected in 6 of the 12 patients with recurrent disease whose treatment-free interval (TFI) was <12 months, whereas none of those with a TFI of ≥12 months had such disease (P = 0.0031).

CONCLUSION

PET or PET/CT is useful for selecting candidates for cytoreductive surgery among patients with recurrent ovarian cancer. To avoid surgical attempts in those with miliary dissemination, patients with a TFI of ≥12 months are the best candidates for cytoreductive surgery.

Clinical utility of positron emission tomography/computed tomography in the evaluation of suspected recurrent ovarian cancer in the setting of normal CA-125 levels

OBJECTIVES

This study was conducted to estimate the accuracy of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as compared with contrast-enhanced CT (CECT) in detecting cancer in patients who have normal cancer antigen (CA)-125 (<35 U/dL) but are suspected of having a recurrent disease based on clinical symptoms.

METHODS

We retrospectively reviewed the records of patients who had undergone primary cytoreductive surgery and subsequently underwent CECT and FDG-PET/CT for suspected recurrence. [18F]-fluorodeoxyglucose positron emission tomography/computed tomography and CECT interpretation to evaluate a recurrent disease was carried out independently by 2 experienced radiologists who were blinded to the final diagnosis for the suspected recurrence. Long-term follow-up imaging (12 months) and biopsy reports were used to assess the true status of the suspected recurrence seen on FDG-PET/CT or CECT. Sensitivity and specificity of all modalities were estimated. McNemar test was used to compare pairs of modalities. All tests were 2-sided, and P < or = 0.05 was considered statistically significant.

RESULTS

Sixty-six patients met the eligibility criteria for inclusion in our analysis. Fifty-eight percent (18/31) and 54% (17/31) of the patients with normal CA-125 levels had evidence of a recurrent disease on FDG-PET/CT and CECT, respectively. Thirty-one percent (6/19) of the patients with no indication of cancer on CECT had evidence of disease on FDG-PET/CT images, which was supported by pathological proof.

CONCLUSION

[18F]-Fluorodeoxyglucose positron emission tomography/computed tomography is capable of detecting ovarian cancer recurrence in symptomatic patients with normal CA-125 levels and, in this setting, has slightly better sensitivity than CECT and can be considered as the frontline modality for all such patients.

Surveillance of patients after initial treatment of ovarian cancer

The surveillance of ovarian cancer patients after initial treatment is a challenging question in clinical practice. Serum CA 125 assay, physical examination, and imaging examinations have been employed with different time schedules for the follow-up of asymptomatic patients. Rising serum CA 125 levels may precede the clinical detection of relapse in 56-94% of cases with a median lead time of 3-5 months. An ongoing randomised phase III European trial is comparing the benefits of early administration of chemotherapy based on serum CA 125 assay alone versus delaying treatment until clinical or radiological detection of recurrent disease. Physical examination, with or without ultrasound, is very useful for the surveillance of these patients, since approximately 25-50% of relapses involve the pelvis. Additional radiological imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), are usually performed in asymptomatic patients with rising CA 125 levels as well as in patients with suspicious symptoms or signs. Integrated positron emission tomography (PET) and CT scanners (PET/CT) can identify recurrent disease in tissues that appear normal at CT imaging as well as metastatic lesions intimately associated with the bowel wall that are difficult to detect with CT or MRI, so that in most series PET/CT has a higher diagnostic reliability than that of conventional imaging techniques. Moreover, PET/CT can disclose unusual supra-diaphragmatic spreading of the disease and may be very helpful for treatment planning, especially for the selection of patients suitable for secondary surgical cytoreduction. A prospective, randomised trial of therapeutic interventions based on stratification by PET/CT disease status could elucidate the real impact of this diagnostic procedure in the management of patients with recurrent ovarian cancer.

Are Surveillance Procedures of Clinical Benefit for Patients Treated for Ovarian Cancer?: A Retrospective Italian Multicentric Study

The aim of this retrospective investigation was to assess the pattern of failures of 412 patients with recurrent ovarian cancer followed up with different surveillance protocols.

Time to recurrence was less than 6 months in 98 women (23.8%), 6 to 12 months in 102 women (24.7%), and more than 12 months in 212 women (51.5%). Symptoms at relapse were referred by 81 women (19.7%). Among the 331 asymptomatic patients, the surveillance procedure that raised the suspect of recurrent disease was clinical examination in 49 (14.8%), imaging technique in 90 (27.2%), serum CA 125 in 77 (23.3%), and both serum CA 125 and imaging technique in 115 (34.7%). At univariate analysis, survival from initial diagnosis was related to stage (P = 0.004), residual disease after initial surgery (P < 0.0001), time to recurrence (P < 0.0001), site of relapse (P = 0.04), and treatment at recurrence (P < 0.0001), and survival after recurrence was related to stage (P = 0.01), residual disease (P < 0.0001), time to recurrence (P < 0.0001), and treatment at recurrence (P < 0.0001). Conversely, symptoms at recurrence had no prognostic relevance. Cox proportional hazards model showed that residual disease and time to recurrence were the only independent prognostic variables for both survival from initial diagnosis (P < 0.0001) and survival after recurrence (P < 0.0001). In conclusion, there was no survival difference between asymptomatic and symptomatic patients at the time of relapse, and therefore, the diagnostic anticipation allowed by a scheduled follow-up protocol did not seem to improve the clinical outcome of patients who ultimately developed recurrent disease.

Performance of integrated FDG-PET/contrast-enhanced CT in the diagnosis of recurrent ovarian cancer: comparison with integrated FDG-PET/non-contrast-enhanced CT and enhanced CT

PURPOSE

The aim of this study was to evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using (18)F-fluorodeoxyglucose with IV contrast for depiction of suspected recurrent ovarian cancer and to assess the impact of PET/contrast-enhanced CT findings on clinical management, compared with PET/non-contrast-enhanced CT and CT component.

METHODS

One hundred thirty-two women previously treated for ovarian cancer underwent PET/CT consisting of non-enhanced and contrast-enhanced CT for suspected recurrence. PET/contrast enhanced CT, PET/non-contrast-enhanced CT, and enhanced CT were interpreted by two experienced radiologists by consensus for each investigation. Lesion status was determined on the basis of histopathology, radiological imaging, and clinical follow-up for longer than 6 months.

RESULTS

Patient-based analysis showed that the sensitivity, specificity, and accuracy of PET/contrast-enhanced CT were 78.8% (52 of 66), 90.9% (60 of 66), and 84.8% (112 of 132), respectively, whereas those of PET/non-contrast-enhanced CT were 74.2% (49 of 66), 90.9% (60 of 66), and 82.6% (109 of 132), respectively, and those of enhanced CT were 60.6% (40 of 66), 84.8% (56 of 66), and 72.7% (96 of 132), respectively. Sensitivity, specificity, and accuracy differed significantly among the three modalities (Cochran Q test: p = 0.0001, p = 0.018, and p < 0.0001, respectively). The findings of PET/contrast-enhanced CT resulted in a change of management for 51 of the 132 patients (39%) and had an effect on patient management in 16 patients (12%) diagnosed by enhanced CT alone and three patients (2%) diagnosed by PET/non-contrast-enhanced CT.

CONCLUSION

Integrated PET/contrast-enhanced CT is an accurate modality for assessing ovarian cancer recurrence and led to changes in the subsequent appropriate therapy.

PET–CT vs. CT alone in ovarian cancer recurrence

BACKGROUND

To compare fusion, positron emission tomography-computed tomography (PET-CT) with CT alone in detecting ovarian carcinoma recurrence.

METHODS

Fifty-one consecutive patients underwent 53 restaging PET-CT scans with a concurrent diagnostic quality CT scan. Two body imaging radiologists independently assessed the CT's; each then teamed with a nuclear medicine specialist to review the PET-CT's. Two teams conferred for consensus on the presence of disease in the chest, abdomen, and body overall with CT alone and with PET-CT, using a six-point reader confidence metric to determine accuracy and receiver operating characteristic (ROC) curves. Reader agreement was compared using kappa. Recurrence was determined by two gynecologic oncologists reviewing clinical records from time of presentation to at least 13 months (mean 22.7) after imaging.

RESULTS

Recurrence was based on histopathology in 17% (9/53). Seventy-two percent (38/53) cases had recurrence, with two cases showing isolated chest recurrence. PET-CT accuracy exceeded CT for body 92% (49/53) vs. 83% (44/53), chest 96% (51/53) vs. 89% (47/53), and abdomen 91% (48/53) vs. 79% (42/53). ROC curves for PET-CT dominated that for CT alone; this difference was statistically significant for abdomen and for body overall (P < 0.01). Interobserver agreement was better for PET-CT than for CT alone.

CONCLUSIONS

PET-CT demonstrates greater accuracy and less interobserver variability than CT alone.

Combined PET/CT for detecting recurrent ovarian cancer limited to retroperitoneal lymph nodes

OBJECTIVE

To evaluate the utility of combined positron emission tomography/computed tomography (PET/CT) for detecting recurrent epithelial ovarian cancer limited to retroperitoneal adenopathy.

METHODS

Fourteen patients (median age = 53 years) with rising serum CA125 levels, and negative or equivocal conventional CT imaging > or = 6 months after primary therapy were retrospectively identified as having recurrent disease limited to retroperitoneal lymph nodes by combined PET/CT and underwent surgical reassessment of targeted nodal basins. Fisher's Exact Test was used to measure the ability of PET/CT to predict isolated retroperitoneal nodal disease.

RESULTS

The median increase in serum CA125 from baseline nadir was 14 U/ml (range = 2-76 U/ml). There were 29 target nodes in 15 nodal basins identified with increased metabolic uptake on combined PET/CT. Eleven patients (78.6%) had recurrent ovarian cancer in retroperitoneal lymph nodes targeted by PET/CT. Of 143 nodes retrieved, 59 contained recurrent ovarian cancer (median nodal diameter = 2.5 cm, range = 0.8-5.2 cm). For all target nodal basins, the sensitivity, specificity, positive and negative predictive values, and accuracy for recurrent ovarian cancer in dissected lymph nodes were: 40.7% (24/59), 94.0% (79/84), 82.8% (24/29), 69.3% (79/114), and 72.0% (103/143) (P < 0.001). PET/CT failed to identify microscopic disease in 59.3% of pathologically positive nodes.

CONCLUSION

Combined PET/CT demonstrates high positive predictive value in identifying recurrent ovarian cancer in retroperitoneal lymph nodes when conventional CT findings are negative or equivocal. The high incidence of occult disease within the target nodal basins suggests that regional lymphadenectomy may be necessary for complete secondary cytoreduction of recurrent disease.

The value of abdominal CT scans in decision-making during chemotherapy in ovarian cancer

OBJECTIVE

During chemotherapy of ovarian cancer many CT scans are performed to assess tumor response during treatment. The aim of this study was to determine the value of abdominal CT scan in the decision to continue chemotherapy or not, after the standard six cycles.

METHODS

All ovarian cancer patients diagnosed between 1991 and 1997 were retrospectively included in the study. Clinical parameters, surgical results, diagnostic test results, and therapeutic strategies were collected from medical records. With logistic modeling those parameters were chosen that predicted best the chance of receiving additional chemotherapy. The chance of receiving further chemotherapy after six cycles based on these parameters was computed and compared to the chance based on CT scan results in addition to these parameters. Arbitrarily we defined a change of over 20% as meaningful.

RESULTS

Eighteen of 50 included patients (36%) received over six cycles of chemotherapy; 29 patients (10%) were at low risk for receiving over six cycles, because they had an optimal debulking surgery and low levels of CA-125 at cycle six. The chance of receiving continued chemotherapy after taking into account positive tumor signs on CT-scan was 22%. This figure further increased to 33% if tumor presence was based on judgment of two CT scans. High-risk patients were patients with suboptimal debulking surgery or patients with an optimal debulking, but high CA-125 levels at cycle six (n = 21). Based on these parameters their chance of receiving additional chemotherapy was 71%, and after taking into account results of one or two CT-scans, the risks increased to 74% and 81%, respectively.

CONCLUSION

CT scans are of no value in deciding the number of chemotherapy cycles in the initial treatment for ovarian cancer. They cost a lot of money, can add a lot of confusion, and offer no benefit over results of debulking surgery and CA-125 levels.

Clinically occult recurrent ovarian cancer: patient selection for secondary cytoreductive surgery using combined PET/CT

OBJECTIVE

The aim of this study was to evaluate the utility of combined positron emission tomography/computed tomography (PET/CT) for identifying ovarian cancer tumor masses > or =1 cm in patients with clinically occult recurrent disease by conventional CT imaging.

METHODS

Twenty-two patients with epithelial ovarian cancer, rising serum CA125 levels, and negative or equivocal conventional CT imaging > or =6 months after primary therapy underwent combined PET/CT imaging followed by surgical reassessment. Fisher's exact test was used to measure the ability of PET/CT to predict macroscopic disease > or =1 cm.

RESULTS

The median patient age was 55 years, and 91% of patients had FIGO Stage IIIC/IV disease. The median increase in serum CA125 was 24 U/ml (range 10 to 330 U/ml). Conventional CT was reported as negative (n = 15) or equivocal (n = 7) in all cases. Eighteen patients were ultimately found to harbor recurrent ovarian cancer measuring > or =1 cm at the time of surgery, with a median maximal tumor diameter of 2.3 cm (range 1.5 to 3.2 cm). The overall patient-based accuracy of PET/CT in detecting recurrent disease > or =1 cm was 81.8%, with a sensitivity of 83.3% and positive predictive value of 93.8% (P = 0.046). Of patients with recurrent ovarian cancer > or =1 cm, complete cytoreduction to no gross residual tumor was accomplished in 72.2%.

CONCLUSION

PET/CT imaging demonstrates high sensitivity and positive predictive value in identifying potentially resectable, macroscopic recurrent ovarian cancer among patients with biochemical evidence of recurrence and negative or equivocal conventional CT findings. In appropriately selected patients, early identification of macroscopic recurrent disease may facilitate complete surgical cytoreduction.

2-[Fluorine-18]-fluoro-2-deoxy-d-glucose positron emission tomography in the diagnosis of recurrent ovarian cancer

OBJECTIVE

The aim of the study was to investigate the role of 2-[fluorine-18]-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the diagnosis of recurrent ovarian cancer.

METHODS

One hundred six FDG PET scans performed in 54 patients in the follow-up after cytoreductive surgery and chemotherapy of ovarian cancer were reevaluated. Fifty-eight scans were performed in patients with suspected recurrence and 48 scans in patients who were clinically disease free. Thirty-seven PET scans were validated by histology and 66 studies by a median follow-up of 22 months in disease-free patients or 12 months in patients with recurrent disease. Three scans were validated by concordant positive findings of tumor marker CA125, computed tomography, and FDG PET.

RESULTS

FDG PET correctly identified recurrent disease in 73/88 cases. PET ruled out recurrent disease in 15/18 cases. The sensitivity and specificity for PET were 83 and 83%, respectively. In patients with suspected disease, sensitivity was 94% compared to 65% in patients judged clinically disease free. The sensitivity of PET was 96% if suspicion of recurrence was based on a rise of CA125 alone. PET preceded the conventional diagnosis by a median of 6 months in patients judged clinically free of disease. The median relapse-free interval after a negative PET scan was 20 months.

CONCLUSION

FDG PET provides the chance to detect recurrent ovarian cancer at an earlier stage during follow-up. Patients with a negative PET scan have a longer relapse-free interval than patients with a positive PET scan.

Value of chest CT scans in routine ovarian carcinoma follow-up

OBJECTIVE

The purpose of our study was to examine the role of chest CT scans in routine follow-up of patients who had been treated for ovarian carcinoma.

MATERIALS AND METHODS

The radiologic follow-up of 127 women with metatastic ovarian carcinoma who had undergone surgery and chemotherapy between 1985 and 1996 was reviewed. In reviewing each patient's medical record, we determined whether a chest CT scan had been obtained, and if so, how many had been obtained during the patient's follow-up period. For patients with a chest CT scan, an analysis of the presence of disease in the thorax and its relation to disease in the abdomen and pelvis, as revealed on CT images, was performed.

RESULTS

Of the patients whose cases were examined, 82 (65%) had had at least one chest CT scan obtained, with more than 50% having had three or more scans. Thirty-two (39%) patients had no radiologic evidence of disease. Twenty-eight (34%) showed disease in the abdomen or pelvis but no disease in the chest. Eighteen (22%) had both chest and abdominal or pelvic CT scans that indicated disease. In all of these patients, abdominal or pelvic disease had appeared on scans before spreading to the chest. Four (5%) of the patients had isolated chest disease. The rate of lung metastases from ovarian carcinoma in our series was 6%. In all of these patients, pulmonary metastases were preceded either by abdominal or pelvic disease or by a rise in tumor markers.

CONCLUSION

Pulmonary metastases in ovarian carcinoma are rare and usually preceded by recurrence of carcinoma in the abdomen or pelvis. We suggest that chest CT scanning could be eliminated in the routine follow-up of patients who have been treated for ovarian carcinoma; yet it should be performed for those patients with elevated serum tumor markers but without evidence of abdominal or pelvic disease.