Evaluating PET‐CT in the detection and management of recurrent cervical cancer: systematic reviews of diagnostic accuracy and subjective elicitation

Abstract

Background Positron emission tomography-computed tomography (PET-CT) is recommended to triage women for exenterative surgery and surveillance after treatment for advanced cervical cancer.Objective To evaluate diagnostic accuracy of additional whole body PET-CT compared with CT/magnetic resonance imaging (MRI) alone in women with suspected recurrent/persistent cervical cancer and in asymptomatic women as surveillance.Design Systematic reviews. Subjective elicitation to supplement diagnostic information. Search strategy/Selection criteria/Data collection and analysisSearches of electronic databases were performed to June 2013. Studies in women with suspected recurrent/persistent cervical cancer and in asymptomatic women undergoing follow up with sufficient numeric data were included. We calculated sensitivity, specificity and corresponding 95% confidence intervals. Meta-analyses employed a bivariate model that included a random-effects term for between-study variations (CT studies) and univariate random effects meta-analyses (PET-CT studies) for sensitivity and specificity separately.Subjective elicitation Prevalence of recurrence and the accuracy of imaging elicited using the allocation of points technique. Coherence of elicited subjective probabilities with estimates in the literature examined.Results We identified 15 relevant studies; none directly compared additional PET-CT with MRI or CT separately. Most CT and MRI studies used older protocols and the majority did not distinguish between asymptomatic and symptomatic women. Meta-analysis of nine PET-CT studies in mostly symptomatic women showed sensitivity of 94.8 (95% CI 91.2-96.9), and specificity of 86.9% (95% CI 82.2-90.5). The summary estimate of the sensitivity of CT for detection of recurrence was 89.64% (95% CI 81.59-94.41) and specificity was 76% (95% CI 43.68-92.82). Meta-analysis for MRI test accuracy studies was not possible because of clinical heterogeneity. The sensitivity and specificity of MRI in pelvic recurrence varied between 82 and 100% and between 78 and 100%, respectively. Formal statistical comparisons of the accuracy of index tests were not possible. Subjective elicitation provided estimates comparable to the literature. Subjective estimates of the increase in accuracy from the addition of PET-CT were less than elicited increases required to justify the use in PET-CT for surveillance.Conclusion Evidence to support additional PET-CT is scarce, of average quality and does not distinguish between application for surveillance and diagnosis. Guidelines recommending PET-CT in recurrent cervical cancer need to be reconsidered in the light of the existing evidence base.

Follow-Up for Cervical Cancer: A Program in Evidence-Based Care Systematic Review and Clinical Practice Guideline Update

“…In addition, most studies involved patients with a suspected recurrence rather than asymptomatic populations undergoing surveillance. For example, the study that made the main contribution to the overall estimates of sensitivity and specificity in Meads et al 9 included both symptomatic and asymptomatic patients and did not distinguish between them 19 . Another study found that, in 103 patients who had a complete metabolic response to treatment 20 , 13 asymptomatic recurrences were detected by pet or pet-ct. Those patients demonstrated better cause-specific survival than did patients who experienced symptomatic recurrences (59% vs. 19%, p = 0.09); however, it is not clear whether the recurrences were also detected by other methods, and thus the added value of pet-ct is not known.…”

“…No studies met the inclusion criteria, and that systematic review was therefore eliminated from further consideration. Two systematic reviews authored by Meads et al 9,10 covered the role of pet-ct in detecting recurrence after complete response to treatment for cervical cancer. The more up-to-date version, which scored highly on the amstar tool for methodologic quality (Table ii), was retained; the older review was excluded from further consideration.…”

“…The more up-to-date version, which scored highly on the amstar tool for methodologic quality (Table ii), was retained; the older review was excluded from further consideration. Using quadas to assess the quality of included diagnostic accuracy studies, Meads et al 9 found that overall study quality was poor because very little information about the characteristics of the study participants was provided and because studies were frequently subject to verification bias. Was the scientific quality of the included studies assessed and documented?…”

Female Pelvis: Genital Organs

“…Differentiation of recurrent disease with fi stula formation due to necrosis may be challenging. Serial follow-up and imaging fi ndings in CT or MRI, such as the presence of a focal enhancing mass or low ADC on DWI and FDG avidity in PET/CT, are typical features of recurrence Meads et al 2014 ).…”

“…Correlation of post-and pretreatment imaging and integration of clinical information including radiation therapy technique, radiation fi eld, dose, and time frame since therapy will allow differentiation of therapy-induced complications from tumor recurrence in the majority of cases (Bluemke et al 1991 ;. Serial follow-up in CT and MRI, advanced MRI using DWI and perfusion studies, and/or PET/CT will assist in problem solving in equivocal cases Meads et al 2014 ).…”