Positron emission tomography/computerised tomography imaging in detecting and managing recurrent cervical cancer: systematic review of evidence, elicitation of subjective probabilities and economic modelling
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- Barts and The London Queen Mary's School of Medicine and Dentistry
Cancer of the uterine cervix is a common cause of mortality in women. After initial treatment women may be symptom free, but the cancer may recur within a few years. It is uncertain whether it is more clinically effective to survey asymptomatic women for signs of recurrence or to await symptoms or signs before using imaging. This project compared the diagnostic accuracy of imaging using positron emission tomography/computerised tomography (PET-CT) with that of imaging using CT or magnetic resonance imaging (MRI) alone and evaluated the CI 77.9% to 93.9%). MRI sensitivities and specificities varied between 82% and 100% and between 78% and 100%, respectively, and CT sensitivities and specificities varied between 78% and 93% and between 0% and 95%, respectively. One small study directly compared PET-CT with older imaging methods and showed more true-positives and fewer false-negatives with PET-CT. The subjective elicitation from 21 clinical experts gave test accuracy results for asymptomatic and symptomatic women and the results for symptomatic women were similar to those from the published literature. Their combined opinions also suggested that the mean elicited increase in accuracy from the addition of PET-CT to MRI and/or CT was less than the elicited minimum important difference in accuracy required to justify the routine addition of PET-CT for the investigation of women after completion of primary treatment. For the effectiveness review, a total of 24,943 citations were identified, of which 62 studies were included (chemotherapy, 19 randomised controlled trials; radiotherapy or chemoradiotherapy, 16 case series; radical hysterectomy and pelvic exenteration, 27 case series). None provided the effectiveness of cisplatin monotherapy, the most commonly used chemotherapeutic agent in the NHS, compared with supportive care in a background of other treatment such as radiotherapy in recurrent and persistent cervical cancer. The model results showed that adding PET-CT to the current treatment strategy of clinical examination, MRI and/or CT scan was significantly more costly with only a minimal increase in effectiveness, with incremental cost-effectiveness ratios for all models being > £1M per quality-adjusted life-year (QALY) and the additional cost per additional case of recurrence being in the region of £600,000. There was considerable uncertainty in many of the parameters used because of a lack of good-quality evidence in recurrent or persistent cervical cancer. The evidence on diagnostic and therapeutic impact incorporated in the economic model was poor and there was little information on surveillance of asymptomatic women. Given the current evidence available, the addition of PET-CT to standard practice was not found to be cost-effective in the diagnosis of recurrent or persistent cervical cancer. However, although probabilistic sensitivity analysis showed that the main conclusion about cost-ineffectiveness of PET-CT was firm given the range of assumptions made, should more reliable information become available on accuracy, therapeutic impact and effectiveness, and the cost of PET-CT reduce, this conclusion may need revision. Current guidelines recommending imaging for diagnosis using expensive methods such as PET-CT need to be reconsidered in the light of the above. The National Institute for Health Research Health Technology Assessment programme.
|Number of pages||323|
|Journal||Health Technology Assessment|
|Publication status||Published - 1 Apr 2013|
- positron, tomography, cervical cacer