National Laboratories Excellence program (under the National Tumor Biology Laboratory
Project(NLP-17)
To describe the results of treating tongue cancer patients with single postoperative
interstitial, high-dose-rate (HDR) brachytherapy (BT) after resection.Between January
1998 and April 2019, 45 patients with squamous cell histology, stage T1-2N0-1M0 tongue
tumours were treated by surgery followed by a single HDR BT in case of negative prognostic
factors (close or positive surgical margin, lymphovascular and/or perineural invasion).
The average dose was 29 Gy (range: 10-45 Gy) and rigid metal needles were used in
11 (24%) and flexible plastic catheters in 34 cases (76%). Survival parameters, toxicities
and the prognostic factors influencing survival were analysed.During a mean follow-up
of 103 months (range: 16-260 months) for surviving patients, the 10-year local and
regional control (LC, RC), overall survival (OS), and disease-specific survival (DSS)
probabilities were 85, 73, 34 and 63%, respectively. The incidence of local grade
1, 2 and 3 mucositis was 23, 73 and 4%, respectively. As a serious (grade 4), late
side effect, soft tissue necrosis developed in 3 cases (7%). In a univariate analysis,
there was a significant correlation between lymphovascular invasion and RC (p = 0.0118)
as well as cervical recurrence and DSS (p < 0.0001).Sole postoperative HDR brachytherapy
can be an effective method in case of negative prognostic factors in the treatment
of early, resectable tongue tumours. Comparing the results of patients treated with
postoperative BT to those who were managed with surgery or BT alone known from the
literature, a slightly more favourable LC can be achieved with the combination therapy,
demonstrating the potential compensating effect of BT on adverse prognostic factors,
while the developing severe, grade 4 toxicity rate remains low.
