Positron emission tomography imaging for gynecologic malignancy

The role of imaging in pelvic exenteration for gynecological cancers

Pelvic exenteration (PE) is one of the most challenging gynecologic oncologic surgeries and is an overriding term for different procedures that entail radical en bloc resection of the female reproductive organs and removal of additional adjacent affected pelvic organs (bladder, rectum, anus, etc.) with concomitant surgical reconstruction to restore bodily functions. Multimodality cross-sectional imaging with MRI, PET/CT, and CT plays an integral part in treatment decision-making, not only for the appropriate patient selection but also for surveillance after surgery. The purpose of this review is to provide a brief background on pelvic exenteration in gynecologic cancers and to familiarize the reader with the critical radiological aspects in the evaluation of patients for this complex procedure. The focus of this review will be on how imaging can aid in treatment planning and guide management.

ACR Appropriateness Criteria® Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD), a rare complication of pregnancy, includes both benign and malignant forms, the latter collectively referred to as gestational trophoblastic neoplasia (GTN). When metastatic, the lungs are the most common site of initial spread. Beta-human chorionic gonadotropin, elaborated to some extent by all forms of GTD, is useful in facilitating disease detection, diagnosis, monitoring treatment response, and follow-up. Imaging evaluation depends on whether GTD manifests in one of its benign forms or whether it has progressed to GTN. Transabdominal and transvaginal ultrasound with duplex Doppler evaluation of the pelvis are usually appropriate diagnostic procedures in either of these circumstances, and in posttreatment surveillance. The appropriateness of more extensive imaging remains dependent on a diagnosis of GTN and on other factors. The use of imaging to assess complications, typically hemorrhagic, should be guided by the location of clinical signs and symptoms. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Squamous cell carcinoma antigen (SCC-Ag) during follow-up of cervical cancer patients: Role in the early diagnosis of recurrence

OBJECTIVE

The aim of this study was to assess the potential benefit of routine squamous cell carcinoma antigen (SCC-Ag) assessment during follow-up of patients after treatment for early cervical cancer with regard to early diagnosis of cancer recurrence before clinical signs and symptoms occur.

METHODS

All clinical, pathological, and serological data of patients referred to the Department of Gynecologic Oncology between July 1999 and June 2014, were retrospectively collected and analyzed. The SCC-Ag levels of 197 patients with diagnosis of stage I or II cervical squamous carcinoma, were performed.

RESULTS

In the univariate analysis, serum SCC-Ag was not significantly associated with grading (p=0.85), LVSI (p=0.95) and FIGO stage (p=0.83) but it was significantly associated with recurrence of disease (p<0.001). The Cox multivariate analyses showed that serum SCC-Ag level was an independent and statistically significant prognostic factor for OS and PFS. The median time interval between SCC-Ag test and diagnosis of recurrence were 0.3 and 1.8months for positive and negative SCC-Ag groups respectively (p=0.01). Considering patients with recurrence, no significant difference in terms of DFS and OS was found between women with high or low SCC-Ag levels.

CONCLUSIONS

Serum SCC-Ag reflects the response to treatment, and rising antigen levels often precede the clinical detection of recurrent disease, and may lead to early diagnosis. However such an advantage does not seem to improve the cure rate of patients with elevated SCC-Ag levels, most likely due to the lack of curative salvage treatments.

Sarcoid-like reaction mimicking vaginal cancer recurrence

A sarcoid-like reaction is a development of non-caseating granuloma in patients with underlying malignancy and represents a false positive finding on positron emission tomography/computed tomography (PET/CT). A sarcoid-like reaction is a benign condition; therefore, differentiating a sarcoid-like reaction from cancer recurrence is necessary. Only uterine and ovarian cancer related cases have been reported in the gynecological field and to the best of our knowledge, this is the first case of a sarcoid-like reaction in vaginal cancer. A 59-year-old vaginal cancer patient received concurrent chemoradiotherapy and achieved complete remission. Recurrence of vaginal cancer was suspected because of the elevation of serum squamous cell carcinoma antigen level. PET/CT revealed abnormal uptake at the bilateral mediastinal and hilar lymph nodes. A non-caseating granuloma was detected from the biopsy of the swollen lymph nodes. No evidence of cancer recurrence was observed. A sarcoid-like reaction should be considered when evaluating PET/CT in cancer patients to prevent unnecessary treatments.

Treatment failure in endometrial carcinoma

OBJECTIVE

Our aim was to investigate the outcomes and prognostic factors after treatment failure of endometrial cancer.

METHODS

A total of 923 endometrial cancer patients were treated between 2000 and 2010, of which 109 experienced treatment failure. Treatment failure was defined as relapse after complete removal of all cancerous lesions or persistent/progressive disease despite treatment. Variables including clinicopathological features at initial treatment, type of primary treatment, failure pattern, salvage treatment, and outcomes were analyzed. Kaplan-Meier survival curves were compared with log-rank test. Cox proportional hazards regression model was used to identify significant prognostic factors.

RESULTS

Eighteen cases with persistent/progressive disease died shortly from primary diagnosis (1-23 months). The remaining 91 patients had recurrences in vagina only (8.8%), pelvis (3.3%), distant (63.7%), and combined pelvic-distant sites (24.2%). Median time to recurrence was 13.3 months (3.2-97.2 months). The median follow-up after recurrence of survivors was 60.5 months (10.6-121.7 months). The median survival after recurrence (SAR) was 20.3 months (1.9-121.7 months) with 5-year SAR rate of 32.4%. By multivariate analysis, initial stage II to IV (hazards ratio [HR], 3.41; 1.53-7.60; P = 0.003), type II histology (HR, 2.50; 1.28-4.90; P = 0.008), positive peritoneal cytology (HR, 2.23; 1.07-4.68; P = 0.033), and recurrence at multiple sites (HR, 2.51; 1.30-4.84; P = 0.006) were significantly associated with poor SAR. The 5-year SAR rates in patients with solitary vaginal, nodal/liver, or pulmonary/bony recurrence were 83.3%, 50.5%, and 24.2%, respectively. Ten cases with resectable or irradiatable recurrence at multiple sites or multiple relapses attained SAR greater than 5 years after multimodality salvage therapy.

CONCLUSIONS

Initial stage II to IV, type 2 histology, positive cytology, and recurrence at multiple sites were significant poor prognostic factors. Curative intent salvage therapy remains a viable option for cases with resectable or irradiatable multiple recurrences and solitary distant metastasis.

Positron emission tomography imaging of endometrial cancer using engineered anti-EMP2 antibody fragments

Purpose

As imaging of the cell surface tetraspan protein epithelial membrane protein-2 (EMP2) expression in malignant tumors may provide important prognostic and predictive diagnostic information, the goal of this study is to determine if antibody fragments to EMP2 may be useful for imaging EMP2 positive tumors.

Procedures

The normal tissue distribution of EMP2 protein expression was evaluated by immunohistochemistry and found to be discretely expressed in both mouse and human tissues. To detect EMP2 in tumors, a recombinant human anti-EMP2 minibody (scFv-hinge-C_H3 dimer; 80 kDa) was designed to recognize a common epitope in mice and humans and characterized. In human tumor cell lines, the antibody binding induced EMP2 internalization and degradation, prompting the need for a residualizing imaging strategy. Following conjugation to DOTA (1,4,7,10-tetraazacyclododecane-N,N′,N′,N′″-tetraacetic acid), the minibody was radiolabeled with ⁶⁴Cu (t_1/2 = 12.7 h) and evaluated in mice as a positron emission tomography (PET) imaging agent for human EMP2-expressing endometrial tumor xenografts.

Results

The residualizing agent, ⁶⁴Cu-DOTA anti-EMP2 minibody, achieved high uptake in endometrial cancer xenografts overexpressing EMP2 (10.2 ± 2.6, percent injected dose per gram (%ID/g) ± SD) with moderate uptake in wild-type HEC1A tumors (6.0 ± 0.1). In both cases, precise tumor delineation was observed from the PET images. In contrast, low uptake was observed with anti-EMP2 minibodies in EMP2-negative tumors (1.9 ± 0.5).

Conclusions

This new immune-PET agent may be useful for preclinical assessment of anti-EMP2 targeting in vivo. It may also have value for imaging of tumor localization and therapeutic response in patients with EMP2-positive malignancies.

High impact of FDG-PET/CT in diagnostic strategies for ovarian cancer

BACKGROUND

Ovarian cancer has the highest mortality of all gynecologic malignancies. FDG-PET/CT was proven to be accurate for identification of primary ovarian tumors, regional lymph nodes, and distant metastases.

PURPOSE

To evaluate ovarian masses at FDG-PET/CT in correlation with histopathologic findings.

MATERIAL AND METHODS

Ninety-eight patients underwent whole body FDG-PET/CT examination. Eighty-six patients with primary ovarian cancer and 12 patients with metastatic disease to the ovaries were included.

RESULTS

PET/CT imaging was true-positive in 87/94 patients with malignant tumors. In 4/4 patients with benign tumors, PET/CT results were true-negative, with sensitivity of 92.6%, specificity 100%, total test accuracy 92.9%. Fifty-seven patients were diagnosed as stage IV ovarian cancer with distant metastasis.

CONCLUSION

The anatomical/functional examination by FDG-PET/CT was proven to be valuable in increasing the diagnostic accuracy that can help improve patient management.

[The accuracy of FDG-PET/CT in early-stage cervical and vaginal cancers]

OBJECTIVE

[(18)F]fluoro-deoxy-glucose positron-emission tomography combined with integrated computed tomography (FDG-PET/CT) is commonly used for advanced stage cervical cancer but its efficiency is discussed in early stage. The aim of this study was to evaluate false negative rate of FDG-PET/CT in early-stage cervical and vaginal cancer.

PATIENTS AND METHODS

Patients treated between 2005 and 2008 for stage IB1 cervical cancer and stage I vaginal cancer who underwent a FDG-PET/CT followed by a pelvic lymphadenectomy were studied.

RESULTS

Eighteen patients were included with bilateral pelvic lymphadenectomy (16 cervical cancer, two vaginal cancer). The median age of patients was 41 years. Radical hysterectomy was performed for 16 patients, by a laparoscopic approach in 15 cases and by a laparotomic approach in one case. One patient had a simple hysterectomy and one had exclusive radiotherapy. No patient had pelvic or para-aortic fixation on FDG-PET/CT. Three patients have proven pelvic involvement and one had para-aortic metastases. The false-negative rate and negative predictive value of FDG-PET/CT were 17% and 83% respectively.

DISCUSSION AND CONCLUSION

The accuracy of FDG-PET/CT imaging in predicting the pelvic nodal status is very low in patients with early-stage cervical and vaginal cancer and is not able to replace surgical exploration.

Methodological quality of test accuracy studies included in systematic reviews in obstetrics and gynaecology: sources of bias

Background

Obstetrics and gynaecology have seen rapid growth in the development of new tests with research on these tests presented as diagnostic accuracy studies. To avoid errors in judgement it is important that the methodology of these studies is such that bias is minimised. Our objective was to determine the methodological quality of test accuracy studies in obstetrics and gynaecology using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist and to assess sources of bias.

Methods

A prospective protocol was developed to assess the impact of QUADAS on ten systematic reviews performed over the period 2004-2007.We investigated whether there was an improvement in study quality since the introduction of QUADAS, whether a correlation existed between study sample size, country of origin of study and its quality. We also investigated whether there was a correlation between reporting and methodological quality and by the use of meta-regression analyses explored for items of quality that were associated with bias.

Results

A total of 300 studies were included. The overall quality of included studies was poor (> 50% compliance with 57.1% of quality items). However, the mean compliance with QUADAS showed an improvement post-publication of QUADAS (54.9% versus 61.4% p = 0.002). There was no correlation with study sample size. Gynaecology studies published from the United States of America showed higher quality (USA versus Western Europe p = 0.002; USA versus Asia p = 0.004). Meta-regression analysis showed that no individual quality item had a significant impact on accuracy. There was an association between reporting and methodological quality (r = 0.51 p < 0.0001 for obstetrics and r = 0.56 p < 0.0001 for gynaecology).

Conclusions

A combination of poor methodological quality and poor reporting affects the inferences that can be drawn from test accuracy studies. Further compliance with quality checklists is required to ensure that bias is minimised.

Case of uterine leiomyoma showing fludeoxyglucose uptake on F-18 fludeoxyglucose positron emission tomography/computed tomography

In order not to over treat uterine leiomyoma and to avoid overlooking uterine leiomyosarcoma, a highly reliable diagnostic method has been thought. Occasionally, it is difficult to discriminate uterine leiomyoma from uterine leiomyosarcoma. Recently positron emission tomography/computed tomography (PET/CT) has been proved useful in assessing pelvic malignancies. We experienced a case of uterine leiomyoma showing increased F-18 fludeoxyglucose uptake on PET/CT in a postmenopausal woman. However, histological analysis demonstrated benign leiomyoma by the hysterectomy. Immunohistochemical analysis of glucose transporter-1 showed negative in leiomyoma. Our case indicates that uterine leiomyoma in a postmenopausal woman may show false positive result of PET/CT.

Use of serum squamous cell carcinoma antigen for follow-up monitoring of cervical cancer patients who were treated by concurrent chemoradiotherapy

Background

To investigate the significance of monitoring the levels of the serum squamous cell carcinoma antigen (SCC-Ag) for the detection of recurrent disease in patients with cervical cancer treated by concurrent chemoradiotherapy.

Methods

The records of 112 patients with cervical cancer were reviewed. Serum SCC-Ag levels were measured at regular follow-up visits. A SCC-Ag level of 2 ng/mL was considered the upper limit of normal. Biochemical failure was defined as two consecutively increasing SCC-Ag values above normal. Recurrent disease was confirmed by histologic and radiographic studies.

Results

Eighteen patients (16%) developed recurrent disease. Sixteen patients had initially elevated SCC-Ag, post-treatment normalization of SCC-Ag, and tumor recurrence. The SCC-Ag difference (ΔSCC-Ag), defined as the difference between the last value after two consecutively increases above normal and the value immediately before the elevation, had good clinical performance in predicting cancer recurrence. The cutoff value of ΔSCC-Ag was 0.95 ng/mL.

Conclusions

SCC-Ag is a relatively good method for the detection of disease recurrence in patients with cervical cancer who were treated by concurrent chemoradiotherapy.

Detection of hematogenous bone metastasis in cervical cancer: 18F-fluorodeoxyglucose-positron emission tomography versus computed tomography and magnetic resonance imaging

BACKGROUND

In this large-scale, retrospective study, the authors evaluated the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET) in detecting hematogenous bone metastasis in patients with cervical cancer. The associated risk factors also were analyzed.

METHODS

Patients with invasive cervical cancer who had both (18)F-FDG-PET studies and CT or MR imaging studies were selected. Patients who had either International Federation of Gynecology and Obstetrics (FIGO) stage III/IV disease or positive lymph node metastasis at the time of primary staging and patients who had suspected recurrent disease were included in the analyses. The diagnostic performances of PET was compared with the performance of CT and MR imaging by using the area under the receiver-operating-characteristic curve (AUC). Both univariate and multivariate analyses were applied to assess the risk factors for hematogenous bone metastasis at primary staging.

RESULTS

PET was more sensitive than CT (P = .004) and was more specific than MR imaging (P = .04). The diagnostic performance of PET was significantly superior to the performance CT (AUC, 0.964 vs 0.662; P < .001) and MR (AUC, 0.966 vs 0.833; P = .033). Both FIGO stage and the extent of lymph node metastases were associated with hematogenous bone metastasis in univariate analysis. However, the extent of lymph node metastases was the only significant risk factor in multivariate analysis (P = .025).

CONCLUSIONS

The current study demonstrated the superiority of (18)F-FDG-PET over CT and MR imaging for detecting hematogenous bone metastasis in patients with advanced cervical cancer. Hematogenous bone metastasis in cervical cancer was associated with the extent of lymph node metastases rather than with FIGO stage.

[Positron emission tomography in the management of cervix cancer patients]

Since its introduction in clinical practice in the 1990's, positron emission tomography (PET), usually with (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG), has become an important imaging modality in patients with cancer. For cervix carcinoma, FDG-PET is significantly more accurate than computed tomography (CT) and is recommended for loco-regional lymph node and extrapelvic staging. The metabolic dimension of the technique provides additional prognostic information. Ongoing studies now concentrate on more advanced clinical applications, such as the planning of radiotherapy, the response evaluation after the induction of therapy, the early detection of recurrence. Technical innovations, such as PET cameras with better spatial resolution and hybrid positron emission tomography/computed tomography (PET-CT), available now on the whole territory, provide both anatomic and metabolic information in the same procedure. From the point of view of biological metabolism, new radiopharmaceutical probes are being developed. Those hold promise for future refinements in this field. This article reviews the current applications of FDG-PET in patients with cervix cancer.

Cesarean section scar mimicking uterine malignant neoplasm at positron emission tomography/computed tomography

Positron emission tomography/computed tomography (PET/CT) is a functional imaging method of metabolic processes and is being used extensively in gynecologic oncology for treatment planning. However, some hypermetabolic conditions may mimic malignant neoplasms. We report a case with a positive finding at PET/CT examination of the uterus that proved to be a cesarean section scar with high expression of glucose transporter-1 and glucose transporter-4. This case report emphasizes the value of the knowledge of patient history and awareness of the limitations of PET/CT to enable a correct diagnosis in patients with positive findings at PET/CT examination.

Role of PET/CT in the detection of liver metastases from colorectal cancer

PURPOSE

The aim of this study was to compare the diagnostic accuracy of 2-[fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG-PET) and computed tomography (CT) with PET/CT in the detection of liver metastases during tumour staging in patients suffering from colorectal carcinoma for the purposes of correct surgical planning and follow-up.

MATERIALS AND METHODS

A total of 467 patients underwent a PET/CT scan using an iodinated contrast medium. We compared images obtained by the single PET scan, the single CT scan and by the fusion of the two procedures (PET/CT). The final diagnosis was obtained by histological examination and/or by the follow-up of all patients, including those who did not undergo surgery or biopsy.

RESULTS

The PET scan had 94.05% sensitivity, 91.60% specificity and 93.36% accuracy; the CT scan had 91.07% sensitivity, 95.42% specificity and 92.29% accuracy. The combined procedures (PET/CT) had the following values: sensitivity 97.92%, specificity 97.71% and accuracy 97.86%.

CONCLUSIONS

This study indicates that PET/CT is very useful in staging and restaging patients suffering from colorectal cancer. It was particularly useful when recurrences could not be visualised either clinically or by imaging despite increasing tumour markers, as it guaranteed an earlier diagnosis. PET/CT not only provides high diagnostic performance in terms of sensitivity and specificity, enabling modification of patient treatment, but it is also a unique, high-profile procedure that can produce cost savings.

Clinical outcome for chemoradiotherapy in carcinoma of the cervix

AIMS

Two recent meta-analyses have shown a survival advantage for the addition of concurrent chemotherapy to radiotherapy in the treatment of cervical cancer. However, there is insufficient information available on late toxicity and few data from UK practice. The aims of this study were to examine treatment outcomes (survival and toxicity) in patients with cervical cancer treated with chemoradiation and to compare these with outcomes in patients treated with radiation alone.

MATERIALS AND METHODS

Between July 2000 and December 2003, 75 patients with cervical cancer were treated with chemoradiation. Case notes were reviewed retrospectively. Acute and late toxicity were recorded, with late toxicity graded using the Franco-Italian glossary. The median age was 47 years. All patients were staged with examination under anaesthesia and magnetic resonance imaging scans. Forty-two patients were treated with concurrent chemoradiation alone and 33 patients were treated with a combination of neoadjuvant and concurrent chemoradiation. This was due to waiting list problems. The chemotherapy used was cisplatin 40 mg/m(2) weekly with radiotherapy, (the neoadjuvant dose was 60 mg/m(2) 3 weekly). External beam radiotherapy was given to the pelvis (40-45 Gy/20 fractions/4 weeks) followed by low dose rate brachytherapy (22.5-32.5 Gy to point A). Patients who were unable to have brachytherapy were given an external beam boost (15-20 Gy/8-10 fractions).

RESULTS

The 3-year overall survival rate was 70%, with an estimated 5-year overall survival rate of 60%. The 3-year disease-free survival was 63.6%, with an estimated 5-year disease-free survival rate of 55%. Compared with the cohort of 183 patients from the Christie Hospital in a 1993 audit, there was a trend towards improved overall survival from 49 to 60% (P=0.06), which may become significant with longer follow-up. There were seven patients (9.3%) with grade 3 toxicity and no cases of grade 4 toxicity. In comparison with patients treated in the 1993 audit, the late toxicity rate has increased from 3.4 to 9.3%, but this was not statistically significant (P=0.14).

CONCLUSION

There was a trend towards improved survival with concurrent chemoradiation in this cohort of patients that may become significant with longer follow-up.

Clinical impact of positron emission tomography or positron emission tomography/computed tomography in the posttherapy surveillance of endometrial carcinoma: evaluation of 88 patients

The objective of this study was to evaluate the validity and clinical impact of positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) using 18-fluoro-2-deoxy-D-glucose in the posttherapy surveillance of patients with endometrial carcinoma. Eighty-eight patients previously treated for histopathologically diagnosed endometrial adenocarcinoma underwent 99 PET or PET/CT scans at follow-up visits at Asan Medical Center, Seoul, Korea, between 2001 and 2007. The standard of reference for tumor recurrence consisted of histopathologic confirmation or follow-up information at least 6 months after PET or PET/CT. Of the 88 patients, 24 underwent PET (n= 11) and/or PET/CT (n= 14) scans due to suspected disease recurrence. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of PET and/or PET/CT in detecting recurrence in these patients were 100%, 83.3%, 96%, 95%, and 100%, respectively. Especially, PET/CT revealed true-positive findings in three patients with elevated tumor markers but negative CT findings. The remaining 64 patients underwent PET (n= 8) and/or PET/CT (n= 66) as part of routine posttherapy surveillance; these patients were asymptomatic, with no evidence of disease. The sensitivity, specificity, accuracy, PPV, and NPV of PET and/or PET/CT in detecting recurrence in these patients were all 100%. Clinical decisions on treatment were changed in 14 (21.9%) patients by introducing PET or PET/CT into their conventional posttherapy surveillance program. PET and/or PET/CT were highly effective in discriminating true recurrence in patients with suspected recurrence, highly sensitive in detecting recurrence in asymptomatic patients, and had impacts on clinical decisions in a considerable portion of patients.

Laparoscopic para-aortic lymphadenectomy and positron emission tomography scan as staging procedures in patients with cervical carcinoma stage IB2IIIB

The objective of this study was to determine the role of laparoscopic lower para-aortic lymphadenectomy and positron emission tomography (PET) scan in the staging of cervical carcinoma. Ninety consecutive patients with FIGO stage IB2-IIIB were scheduled for laparoscopic para-aortic lymphadenectomy.

EXCLUSION CRITERIA

obvious metastatic para-aortic nodes on computed tomography (CT)/PET or PET-CT. The procedure was stopped when a node was positive on frozen section. In ten patients, no para-aortic lymphadenectomy was performed as scheduled. Forty-seven patients were operated retroperitoneally, 22 transperitoneally, and 21 cases were converted from retroperitoneally to transperitoneally. Median number of removed nodes was 6 (1-24). In 10 of 80 patients, para-aortic metastases were diagnosed. Despite a nonsuspect PET result, 5 of 44 patients had positive para-aortic nodes. Two-year survival was 76% and 16% without and with para-aortic metastases, respectively (P = 0.0001). Laparoscopic para-aortic lymphadenectomy showed metastases in 13% of the patients. In the subgroup with negative PET scan, 11% had metastases. The procedure had a low morbidity and identified a group with an extremely poor prognosis.

Histologic Results of Para-Aortic Lymphadenectomy in Patients Treated for Stage IB2/II Cervical Cancer With Negative [18F]Fluorodeoxyglucose Positron Emission Tomography Scans in the Para-Aortic Area

Purpose

Histologic results of complete para-aortic lymphadenectomy were studied in patients treated for stage IB2/II cervical carcinoma who had no para-aortic uptake on [18F]fluorodeoxyglucose positron emission tomography combined with integrated computed tomography (FDG-PET/CT).

Patients and Methods

Patients were treated between 2004 and 2006 for stage IB2/II cervical cancer. Magnetic resonance imaging of the abdomen and pelvis and FDG-PET/CT were initially performed. Patients with no para-aortic abnormalities were treated with external pelvic radiation therapy and concomitant chemotherapy followed by utero-vaginal brachytherapy. Para-aortic lymphadenectomy was then performed. FDG-PET/CT images were reviewed by two nuclear medicine specialists.

Results

Thirty-eight patients were studied. Three patients had histologically proven para-aortic involvement (metastatic nodes with capsular rupture in the para-aortic area), leading to a negative predictive value of 92% for para-aortic nodal involvement.

Conclusion

In this study, three of 38 patients with no para-aortic uptake on [18F]FDG-PET/CT imaging had histologically proven para-aortic node involvement. PET/CT imaging without histologic examination of the para-aortic area used to determine radiation therapy fields in stage IB2/II cervical cancer would overlook 8% of patients with histologic para-aortic nodal involvement.

Role of PET or PET/CT in the post-therapy surveillance of uterine sarcoma

OBJECTIVE

To evaluate the clinical accuracy and clinical impact of positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) in detecting and treating tumor recurrence in patients with treated uterine sarcoma.

METHODS

Results of 36 patients who underwent PET or PET/CT in post-therapy surveillance of uterine sarcoma were retrospectively assessed. Histopathologic confirmation or clinical/radiological outcome at least 6 months after PET or PET/CT was standard of reference.

RESULTS

The 36 patients underwent 48 PET or PET/CT scans as part of post-therapy surveillance. Thirty scans (8 PET and 22 PET/CT) were performed due to suspicion of disease recurrence on CT, whereas 18 scans (4 PET and 14 PET/CT) were performed as part of routine post-therapy surveillance in asymptomatic patients. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of PET or PET/CT were 92.9%, 100%, 94.4%, 100% and 80%, respectively, in patients with suspected recurrence and 87.5%, 95.5%, 93.3%, 87.5% and 95.5%, respectively, in asymptomatic patients. PET or PET/CT influenced the management of 12 patients (33.3%), by initiation of previously unplanned treatment in 8 patients and by avoidance of previously planned treatment in 4 patients.

CONCLUSION

PET or PET/CT was highly effective in discriminating true recurrence in patients with suspected recurrence and was highly sensitive in detecting recurrence in asymptomatic patients. It had impacts on clinical decision making in a high proportion of patients.

Comparison of the validity of magnetic resonance imaging and positron emission tomography/computed tomography in the preoperative evaluation of patients with uterine corpus cancer

OBJECTIVE

To compare positron emission tomography/computed tomography (PET/CT) with magnetic resonance imaging (MRI) in the preoperative detection of primary lesions and lymph node (LN) and distant metastases in patients with uterine corpus cancer.

METHODS

The patient cohort consisted of 53 women with uterine corpus cancer who underwent preoperative workup, including both MRI and PET/CT scans, and underwent surgical staging, including pelvic and/or paraaortic LN dissection, between October 2004 and June 2007 at Asan Medical Center, Seoul, Korea. Pathologic data from surgical staging were compared with the preoperative MRI and PET/CT results. For area specific analysis, LNs were divided into paraaortic, right pelvic and left pelvic areas.

RESULTS

In detecting primary lesions, MRI and PET/CT showed no differences in sensitivity (91.5% vs. 89.4%), specificity (33.3% vs. 50.5%), accuracy (84.9% vs. 84.9%), positive predictive value (PPV) (91.5% vs. 93.3%) and negative predictive value (NPV) (33.3% vs. 37.5%). With MRI, the sensitivity, specificity, accuracy, PPV and NPV for detecting metastatic LNs on LN area-by-area analysis were 46.2%, 87.9%, 83.9%, 28.6% and 94.0%, respectively; With PET/CT, those were 69.2%, 90.3%, 88.3%, 42.9%, and 96.6%, respectively. PET/CT showed higher sensitivity, but it did not reach statistical significance (p=0.250). There were also no differences in specificity, accuracy, PPV and NPV. In detecting distant metastasis, the sensitivity, specificity, accuracy, PPV and NPV of PET/CT were 100%, 93.8%, 92.5%, 62.5% and 100%, respectively.

CONCLUSION

In patients with uterine corpus cancer, PET/CT had moderate sensitivity, specificity and accuracy in detecting primary lesions and LN metastases, indicating that this method cannot replace surgical staging. The primary benefit of PET/CT is its sensitivity in detecting distant metastases. Because of its high NPV in predicting LN metastasis, PET/CT may also have advantages in selected patients who are poor candidates for surgical staging.

The serum assay of tumour markers in the prognostic evaluation, treatment monitoring and follow-up of patients with cervical cancer: a review of the literature

Pre-treatment serum squamous cell carcinoma antigen [SCC] levels are elevated in 28-88% of patients with squamous cell cervical cancer, and are related to tumour stage, tumour size, depth of stromal invasion, lymph-vascular space status, parametrial involvement and lymph node status. The clinical relevance of pre-treatment serum SCC assay is still debated. Some authors reported that it has no prognostic value, some others found that it is related to survival at univariate analysis, and some others detected that is an independent prognostic variable for survival. Serial SCC measurements reflect both the tumour response to treatment and the clinical outcome of patients. Increasing SCC levels can precede the clinical diagnosis of recurrent disease in 46-92% of the cases, with a mean lead time ranging from 2 to 8 months. According to some authors serum SCC assay during the follow-up does not improve the cure rate of patients who will ultimately develop a recurrence. However, it has been recently reported that the performance of a positron emission tomography [PET] in patients with asymptomatic SCC elevation can sometimes allow an earlier diagnosis of relapse with a survival benefit. SCC is a more sensitive serum tumour marker than CYFRA 21-1 for squamous cell cervical cancer in most series. Pre-treatment CA 125 levels are raised in 20-75% of patients with cervical adenocarcinoma, and reflect tumour stage, tumour size, histological grade, cervical stromal invasion, lymph-vascular space status and lymph node status. Elevated serum CA 125 has been also detected in patients with squamous cell cervical cancer, but with a positivity rate lower than that found in patients with cervical adenocarcinoma. Pre-treatment CA 125 levels appear to have a prognostic value, and rising serum CA 125 during follow-up may precede or be coincident with the clinical diagnosis of recurrent cervical adenocarcinoma. Serum levels of vascular endothelial growth factor [VEGF] are often elevated in patients with cervical cancer, and decrease significantly after successful treatment. However, the clinical relevance of serum VEGF assay is still investigational.

Biochemical prognostic factors and risk of relapses in patients with cervical cancer

No validated tumor marker is currently available for the management of patients with cervical cancer. However, some tumor-associated antigens have been measured in the sera from patients with this malignancy and have been related to the clinical course of disease. Squamous cell carcinoma antigen (SCC) is more sensitive than CYFRA 21-1 for squamous cell cervical cancer. Serum SCC levels are elevated in 28-88% of patients with this malignancy, and correlate with tumor stage, tumor size, cervical stromal invasion, lymph-vascular space involvement, and lymph node status. Some authors reported that pre-treatment serum SCC has no prognostic value, whereas others found that it is related to disease-free survival and/or overall survival at univariate analysis or at multivariate analysis. Serial SCC measurements correlate with tumor response to radiotherapy and/or chemotherapy and the clinical outcome of patients. Increasing serum SCC can precede the clinical diagnosis of relapse in 46-92% of cases, with a median lead time ranging from 2 to 8 months. According to some authors serum SCC assay during the follow-up does not improve the cure rate of patients who will ultimately develop a recurrence. However, it has been recently reported that the performance of a PET in asymptomatic patients with serum SCC elevation can sometimes allow an earlier diagnosis of relapse with a survival benefit. Serum CA 125 levels are raised in 20-75% of patients with cervical adenocarcinoma, and reflect tumor stage, tumor size, histological grade, cervical stromal invasion, lymph-vascular space involvement, and lymph node status. Pre-treatment CA 125 levels appear to have a prognostic value, and rising serum CA 125 may precede or be coincident with the clinical diagnosis of recurrent cervical adenocarcinoma.