Plain English Summary
Background and study aims
Differentiated thyroid carcinoma (DTC) (also known as thyroid cancer) is commonly known to recur in patients with advance cases. The aim of this study is to find out how effective is external beam radiotherapy of the neck region in patients with locally advanced thyroid carcinoma for prevention of locoregional recurrence of disease.
Who can participate?
Adults aged 18 and older who were treated with radiotherapy for thyroid carcinoma.
What does the study involve?
Participants with DTC who had external beam radiotherapy of the neck and mediastinum as part of multimodal treatment of locally advanced tumor from year 1973 to 2015 have their medical notes reviewed for information about the control rate and survival.
What are the possible benefits and risks of participating?
There are no benefits or risks with participating in this study.
Where is the study run from?
Institute of Oncology Ljubljana (Slovenia)
When is the study starting and how long is it expected to run for?
June 2010 to January 2018
Who is funding the study?
Slovenian Research Agency (AARS) (Slovenia)
Who is the main contact?
Professor Nikola Besic (Scientific)
Locoregional Disease Control after External Beam Radiotherapy in Patients with Differentiated Thyroid Carcinoma and pT4 Tumor Stage
LC EBRT DTC
Our aim was to find out the rate of locoregional control of the disease after external beam radiotherapy (EBRT) of the neck and mediastinum in patients with DTC and pT4 tumor.
Protocol Review Board Ethics Committee of the Institute of Oncology, 18/11/2010, ref: KSOPKR/18/11/10
Retrospective single-centre observational study
Primary study design
Secondary study design
Patient information sheet
No participant information sheet available
Differentiated thyroid carcinoma - pT4 tumor stage
All 91 patients included in this report had EBRT to the neck and superior mediastinum. Six patients were treated preoperatively with EBRT, four of them with concomitant chemotherapy and two with EBRT only. Even 63 (69%) of our patents were irradiated using antero-posterior opposed fields in supine position with extended neck. The target volume extended from mastoid tips cranially to tracheal bifurcation caudally and to the coracoids laterally, to cover neck lymph nodes regions I-VI, thyroid bed and superior mediastinal lymph nodes. The two beams, using Cobalt unit or 6 MV photon beams, were weighted anteriorily; dose from the anterior field was 1.2 Gray (Gy) and from posterior field 0.6 Gy per fraction, 5 fractions per week. The apices of the lungs were shielded; after the received dose of 39.6 Gy. The spinal cord was also shielded from the posterior field, so the dose to the spinal cord was kept bellow 45 Gy. The prescribed dose to the midplane in vast majority of postoperative patients was 50.4 Gy. A boost dose of 6 - 16 Gy with 1.8 - 2 Gy per fraction was delivered to some patients with macroscopic remnant of disease using photon beams or electron beams avoiding spinal cord. Eight patients were irradiated by 3D technique (TD 50.4-70 Gy, median 63.5 Gy) and 20 patients by intensity-modulated radiotherapy (IMRT) technique (TD 56-70 Gy, median 64 Gy) to the whole neck and mediastinum, while only one patient had only thyroid bed irradiation. The five of six patients treated with EBRT before surgery received 36 Gy before surgery and 14 Gy after surgery, while one patient treated with EBRT before surgery received 50 Gy with IMRT technique.
Patients medical notes are reviewed to take information about locoregional recurrence, cause specific survival and overall survival.
Primary outcome measures
Locoregional control rate was calculated by reviewing patient charts at five and ten years after external beam radiotherapy.
Secondary outcome measures
1. Cause-specific survival was calculated using survival curves from patient charts at five and ten years after initial therapy
2. Overall survival was calculated using survival curves from patient charts at five and ten years after initial therapy
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Differentiated thyroid carcinoma -pT4 tumor stage
2. Males or females older than 18 years of age
Target number of participants
All 91 patients treated with external beam irradiation at the Institute of Oncology Ljubljana from the year 1973 to 2015.
Participant exclusion criteria
Younger than 18 years of age.
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Institute of Oncology Ljubljana
Institute of Oncology
Institute of Oncology
+386 158 79518
Slovenian Research Agency (AARS)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in BMC Cancer.
IPD sharing statement:
We will not provide a dataset because it is in Slovenian language. The dataset will be held in archives of the Research Department of the Institute of Oncology Ljubljana.
Intention to publish date
Participant level data
Not expected to be available
Results - basic reporting