Summary 

Introduction:

High-dose-rate brachytherapy (HDR-BT) is a type of internal radiation therapy, which consists of placing a radioactive source inside the body or close to the tumour, and allows for treatment to be administered in a very short time. Moreover, the radioactive substance does not remain in the patient.
Cancers of the mobile portion of the tongue are located in front of the circumvallate papillae and affect the anterior two thirds of the organ. These tumours account for 50% of diseases of the oral cavity.
Objectives: The main objective of this study was to assess the safety and effectiveness of HDR-BT in the treatment of tumours of the mobile tongue. The main specific objectives were to assess the benefits in terms of safety, loco-regional control, distant metastasis and survival with respect to other treatments.

Methods:

In June 2014, we conducted a systematic search of the scientific literature contained both in leading computerised biomedical databases, such as PubMed, Embase, ISI Web of Knowledge, Centre for Reviews and Dissemination, Cochrane, etc., and in databases of ongoing studies (ClinicalTrials.gov, Current Controlled Trials, etc.). In addition, we also conducted a general Internet search to locate grey literature. After drawing up and defining a series of selection criteria, we included all studies that fulfilled these criteria and excluded -among others- those that assessed different brachytherapy techniques jointly. Data were collected and summarised in evidence tables, with quality being assessed using the SIGN scale.

Results:

The study encompassed a systematic review, which covered a total of 14 publications that met our selection criteria, and two further studies not included in the review. With the exception of one clinical trial, all the remaining (case-control and case-series) studies were retrospective and thus reported assessments of historical series of patients. The studies were conducted on patients with early stage T1-3N0 tumours of the tongue: in some instances, patients with stage T4 disease and positive ganglia involvement were included, mostly in studies with administration of external radiotherapy in addition to brachytherapy. In the majority of studies, patients treated with HDR-BT registered toxicity rates that were higher than or similar to those obtained in the studies on low-dose-rate brachytherapy (LDR-BT). Local control and survival were similar with both techniques. These results were reported by most of the studies, including the small-sized clinical trial. Studies that administered brachytherapy jointly with external radiotherapy reported widely differing outcomes.

Conclusions and recommendations:

Isolation of patients and irradiation of healthcare staff are both avoided with HDR-BT, yet the evidence found is nevertheless heterogeneous and of moderate-low quality. Despite the fact that the general results on effectiveness proved similar for HDR-BT and LDR-BT, doubts surrounding safety make it impossible to establish recommendations for use at the present.