Lateral X-ray view of the skull for the diagnosis of adenoid hypertrophy: a systematic review

Abstract

Objectives: Many studies have been developed aiming to reveal the usefulness of cavum X-rays and telerradiographies as diagnostic tools for the detection of upper airway obstruction due to adenoid hypertrophy. However, the scientific literature is diverse and controversial. Therefore, a systematic review is proposed; with the objective to determine the diagnosis value of lateral X-ray view of the skull regarding adenoid hypertrophy.

Methods: Searching was conducted on Pubmed, Lilacs, Cochrane Library, Embase, and Web of Knowledge databases; and was restricted to studies published in English, Portuguese or Spanish languages, carried out on humans under 18 years of age. All the obtained publications were first submitted to a pre-selection, and then, full-texts (n=66) were analyzed and selected by independent examiners. The resultant studies (n=11) were systematically and critically analyzed, and qualified according to QUADAS (Quality Assessment of Diagnostic Accuracy Studies) questionnaire, an assessment tool designed to qualify diagnostic tests accuracy studies.

Results: Searching and selection procedures generated 11 studies which were considered adequate to be systematically analyzed. Accordingly, large variation was observed concerning the evaluation methods of radiographic and fibronasoendoscopic exams, and the sample characteristics. Additionally, little amount of scientific evidences could be provided, since few radiographic variables were analyzed simultaneously. Moreover, assessment methods were, at most, subjective or poorly described. QUADAS application revealed other significant limitations related to the sampling, such as inadequate spectrum of the investigated "disease" (adenoid hypertrophy), and poor report of the subjects' enrollment and participation process. Further, QUADAS revealed inadequacies regarding methodological features, including poor description of the radiographic exams and assessment methods. In addition, it was also shown that most of the studies did not specify the moment in clinical time when both exams were performed; neither reported a strategy of "blindness" by the examiners.

Conclusions: Despite such limitations, the majority of the resultant data indicates that lateral X-rays might be considered somewhat useful, even though it could not be clearly demonstrated. Future research should then adhere to greater methodological rigor, in order to investigate the significance of radiographies as a screening test.