Clarifying the Diagnosis of Clinically Suspected Recurrence of Cervical Cancer: Impact of ¹⁸F-FDG PET

Abstract

Clarifying the diagnosis of clinically suspected recurrence of cervical cancer can be challenging. The aim of this study was to investigate the clinical value of 18 F-FDG PET in this context. Methods: The medical records of a cohort of 40 18 F-FDG PET referrals in whom recurrence of cervical cancer was clinically suspected were reviewed. Two expert gynecologic oncologists assessed the level of pre-PET clinical doubt, quality of pre-PET work-up, and impact of 18 F-FDG PET on diagnostic understanding and management using questionnaires. Results: In patients with clinically equivocal recurrence, 18 F-FDG PET had a sensitivity of 92% and a specificity of 93% (prevalence, 65%). Before 18 F-FDG PET, there was high disagreement about the adequacy of the conventional work-up (intraclass correlation coefficient [ICC], 0.25) and the presence of recurrence (ICC, 0.24). 18 F-FDG PET increased experts' confidence (median increase, 14% and 25%; P , 0.0001) and diagnostic agreement (from 68% to 98%; ICC, from 0.24 to 0.95). When 18 F-FDG PET was positive for recurrence, the median overall survival was 13 mo. For patients with negative 18 F-FDG PET findings, the median survival was not reached (log rank, 15.50, P 5 0.0001). When the treatment plan was categorized as local therapy, systemic therapy, and expectative management, 18 F-FDG PET changed the treatment plan in half of all cases. The 2 experts reported that 18 F-FDG PET led to a better diagnosis and a beneficial change in management in, respectively, 60% and 65% of cases. Conclusion: 18 F-FDG PET can help to clarify the diagnosis of clinically suspected recurrence of cervical cancer. In this patient population, 18 F-FDG PET had significant value in diagnostic understanding and management of recurrent cervical cancer, facilitating decision making and treatment planning. Therefore, 18 F-FDG PET should be part of the diagnostic work-up in detection of recurrent cervical cancer. The high positive predictive value of 18 F-FDG PET in these patients suggests that inclusion in intervention trials might be based on a positive 18 F-FDG PET scan.

Gynecologic Oncologic Imaging With PET/CT

“…The large range of PPVs was related to a study investigating the use of FDG-PET for detecting early recurrence in patients without clinical evidence of recurrence, a setting in which one could postulate that a higher false-positive rate might be expected. In the study by Van der Veldt et al, 38 the sensitivity Figure 2 A 66-year-old woman with high-grade müllerian cervical adenocarcinoma, initially treated with chemotherapy and radiation. FDG-PET/CT for the subsequent treatment strategy revealed multiple bilateral FDG-avid pulmonary nodules.…”

“…37 Conversely, metabolism is usually higher in recurrent malignancy than in posttreatment scarring, and FDG-PET and PET/CT have been shown to be effective in detecting recurrent tumor. [38][39][40][41] The results of several of these studies are summarized in Table 2. The studies included different patient populations and a meta-analysis as well as different techniques (FDG-PET alone vs PET/CT).…”

Management of recurrent cancer of the uterine cervix

“…PET has a high positive predictive value and is recommended in all cases of recurrent cervical cancer [5]. The recurrence should be proved by a biopsy in all cases [6].…”

PET in uterine malignancies

“…In disease re-staging, conventional CECT and MRI are the most frequently used imaging modalities, even if some limitations should be taken into account: first of all, they are generally limited to one body district (pelvis and/or abdomen); secondly, they are often unable to identify cancer relapse in body districts which present post-surgical or post-radiotherapy scars (good sensitivity, but low specificity levels); thirdly, they are inaccurate in characterizing small lymph nodes and in detecting the peritoneal disease [52]. Therefore, as described by van der Weldt [53] the results of the above-mentioned exams are often inconclusive and equivocal, thus justifying the use of PET. In this study the 18 F-FDG-PET/CT scan showed a good sensitivity and specificity: 92% and 93% respectively.…”