External Beam Radiotherapy

Guidelines on radioiodine therapy for differentiated thyroid carcinoma

“…)atthe time of initial surgery, completion of primary surgical therapy with R0 (no tumour residues) or R1 (microscopic residues) resection, Karnofskyi ndex ≥ 70%, freedom from distant metastases at the time of initialRIT,and informed patientconsent (41). Patients whoagreed to randomization were randomized into treatment arms A (RTx) or B(no RTx) at the time of the first 131 Iscintigraphy 3-4 months afterinitial RIT (8,46). In case of centers notparticipating in randomization or patients refusing randomization,p atients were assignedt oe ither treatment armb yt he referring physicians.…”

“…Thus,t he basiso fm anyr ecommendations(e. g. on the optimum levelofTSH suppression) is not transparent. This includesvalue judgments made by the guideline development group when benefits are weighed againstharms (56).This maylead to conflicting guideline recommendations between different expert groups (30), for example regarding the role of adjuvantRTx of DTC (8,18,46) or recommendationsfor treating thyroid microcarcinoma (22,25,26,53). Therei sa lsoaconflict whether guidelines should be "user-friendly" and simple,o rh avem ore regard to special circumstances (5).…”

Clinical outcomes of adjuvant external-beam radiotherapy for differentiated thyroid cancer

“…MSDS was planned as a prospective randomized trial on the clinical benefit of adjuvant external beam radiotherapy (RTx) (3) for locally invasive differentiated thyroid carcinoma Biermann et al: External beam radiotherapy for differentiated thyroid cancer Nuklearmedizin 3/2009© Schattauer 2009 The benefit of external beam radiotherapy therapy (RTx) in addition to surgery, radioiodine ( 131 I) therapy (RIT) and thyroidstimulating hormone (TSH) suppressive therapy for differentiated thyroid cancer (DTC) has long been a subject of debate (1).…”

“…In centres not participating in randomization, patients were assigned to either treatment arm by the referring physicians. The power calculation underlying the trial was based on the assumption of a cumulative recurrence rate of 19% in the non-irradiated arm over a 5-year recruitment and a 3-year follow-up period (1,12). It demanded a sample size of 2 × 250 randomized patients in order to detect a 50% reduction in recurrence rate by RTx with 80% power (Fisher's exact test, p < 0.05, two-tailed) (1).…”

“…At the time of each WBS, TSH, serum thyroglobulin (Tg), Tg-recovery (TgR) and anti-Tg-antibodies (TgAB) and blood cell count were required as well as an ultrasound (US) examination of the neck. For patients in treatment arm A, RTx was begun after documented complete elimination of cervical 131 I uptake in a diagnostic WBS, if necessary after repeat RIT (1,3,19,27) in accordance with the current German radiotherapy guidelines (28). RT included the thyroid bed with a dose of 59.4 Gy and 66.6 Gy after R0 and R1 resection, resp., and the regional lymph nodes of the neck and upper mediastinum including the posterior cervical chain from the mandible and mastoid process to the tracheal bifurcation with a dose of 50.4 Gy and 54.0 Gy in pN0 and pN1/x disease, resp.…”