Results of sole postoperative interstitial, high-dose-rate brachytherapy of tongue tumours
Zoltan Takacsi-Nagy,
Hungary
OC-0615
Abstract
Results of sole postoperative interstitial, high-dose-rate brachytherapy of tongue tumours
Authors: Zoltan Takacsi-Nagy1, Ors Ferenczi2, Tibor Major1, Hironori Akiyama3, Georgina Frohlich4, Ferenc Oberna5, Monika Revesz5, Marton Poosz4, Csaba Polgar1
1National Institute of Oncology, Centre of Radiotherapy (Semmelweis University, Department of Oncology), Budapest, Hungary; 2National Institute Of Oncology, Centre of Radiotherapy, Budapest, Hungary; 3Osaka Dental University, Department of Oral Radiology, Osaka, Japan; 4National Institute of Oncology, Centre of Radiotherapy, Budapest, Hungary; 5National Institute of Oncology, Multidisciplinary Centre of Head and Neck Tumours, Budapest, Hungary
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Purpose or Objective
To describe the results of treating tongue
cancer patients with single postoperative interstitial, high-dose-rate (HDR)
brachytherapy (BT) after resection.
Material and Methods
Between January 1998 and April 2019, 47
patients with squamous cell histology, stage T1-3N1M0 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 29.6 Gy (range: 10-45 Gy) and rigid metal
needles were used in 11 (23%) and flexible plastic catheters in 36 cases (77%).
The survival parameters and toxicities were analysed and also the prognostic
factors influencing survival.
Results
During a mean follow-up of 96 months
(range: 16-260 months) for surviving patients, the probability of 10-year local
and regional control (LC, RC), overall survival (OS), and disease-specific
survival (DSS) was 86%, 73%, 35% and 64%, respectively. The incidence of local
grade 1, 2 and 3 mucositis was 21%, 75% and 4%, respectively. As a serious (grade
4), late side effect, soft tissue necrosis developed in 3 cases (6%). In a
univariate analysis, there was a significant correlation between lymphovascular
invasion and RC (p=0.023) as well as cervical recurrence and DSS (p˂0.0001).
Conclusion
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.