Radiotherapy in thyroid carcinoma

• Register: ISRCTN
• Last refreshed on: 12 February 2018
• Main ID: ISRCTN27923044
• Date of registration: 12/01/2018
• Prospective Registration: No
• Primary sponsor: Institute of Oncology
• Public title: Radiotherapy in thyroid carcinoma
• Scientific title: Locoregional Disease Control after External Beam Radiotherapy in Patients with Differentiated Thyroid Carcinoma and pT4 Tumor Stage
• Date of first enrolment: 01/01/2013
• Target sample size: 91
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN27923044
• Study type: Observational
• Study design: Retrospective single-centre observational study (Treatment)

Countries of recruitment

Slovenia

Contacts

• Name: Nikola Besic

Key inclusion & exclusion criteria

Inclusion criteria: 1. Differentiated thyroid carcinoma -pT4 tumor stage
2. Males or females older than 18 years of age
Exclusion criteria: Younger than 18 years of age.

Age minimum:
Age maximum:
Gender: Both

Health Condition(s) or Problem(s) studied

Differentiated thyroid carcinoma - pT4 tumor stage
Cancer
Differentiated thyroid carcinoma - pT4 tumor stage

Intervention(s)

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(s)

Locoregional control rate was calculated by reviewing patient charts at five and ten years after external beam radiotherapy.

Secondary Outcome(s)

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

Secondary ID(s)

OI-RTX-DTC

Source(s) of Monetary Support

Slovenian Research Agency (AARS)

Ethics review

Status:
Approval date:
Contact:

Protocol Review Board Ethics Committee of the Institute of Oncology, 18/11/2010, ref: KSOPKR/18/11/10

Results

• Results available: Yes
• Date Completed: 04/01/2018