RADIOTHERAPY FOR HEAD AND NECK CANCER INDUCES PULP NECROSIS? SYSTEMATIC REVIEW WITH META-ANALYSIS

Abstract

The aim of this review was to answer the question whether radiotherapy in patients with head and neck cancer can induce pulp necrosis. Searches were performed based on the PICOS strategy in the following databases: PubMed, Cochrane Library, EMBASE, Web of Science, Scopus and Open Grey. Only clinical studies that assessed the pulp status of patients with head and neck cancer undergoing radiotherapy were selected. Risk of bias was accessed using the ROBINS-I tool. Meta-analyses were performed using fixed effects models. The quality of evidence was accessed with the GRADE tool. Of 171 studies identified in the initial searches, 68 were removed as they were duplicates. After titles and abstracts reading, 5 studies were included for final analysis. Pulp status was verified by cold thermal testing (CTT), electrical testing (ET) and pulse oximetry (PO). In general, treatments consisted of isolated radiotherapy using intensity- modulated radiotherapy (IMRT), with total doses between 60-70Gy. 

Significant changes for CTT responses were observed in post-radiotherapy periods(n=4;I2=0%;95%CI;P< 0.00001/n=3;I2=0%;95%CI;P< 0.00001), being mostly negative responses. Significant changes in ET were seen in post-radiotherapy periods(n=2;I2=68%;95%CI;P< 0.00001), with a significant increase in the electrical dose for response. PO revealed a significant reduction in pulpal blood flow with the consequent return to normal values, however, meta-analyses were not possible. Three studies had a serious risk of bias, and two a moderate risk. GRADE analysis showed a moderate quality of evidence. Radiotherapy in patients with head and neck cancer does not induce pulp necrosis. CTT and ET should not be used as conclusive diagnostic methods of necrosis.