The effect of laryngectomy and postoperative radiotheraphy on thyroid gland functions

Abstract

Objectives: We investigated the frequency of hypothyroidism in patients treated with total laryngectomy, hemithyroidectomy-isthmectomy, and postoperative radiotherapy for T3 or T4 larynx cancers.Patients and Methods: Twenty-nine male patients mean age 54 years; range 43 to 72 years with T3 or T4 larynx cancers were prospectively included in the study.Preoperatively, thyroid function tests were normal in ali the patients. Follovving radiotherapy, serum thyroid-stimulating hormone sTSH , free triiodothyronine FT3 , and free thyroxine FT4 levels were measured every three months at least for a year. Detection of an increased level of sTSH together with decreased or normal levels of FT3 and/or FT4 indicated clinical and subclinical hypothy- roidism, respectively. The relationship was assessed betvveen hypothyroidism and both age and radiotherapy dosage. Statistical analyses were made with the use of the Student’s t- test and Mann-Whitney U-test.Results: Follovving radiotherapy, thyroid function tests remained normal in 12 patients 41% , vvhile 12 patients 41% and five patients 18% developed subclinical and clin­ ical hypothyroidism, respectively. No significant relationship vvas found betvveen age and thyroid dysfunction p>0.05 , vvhereas radiotherapy dosage vvas found in significant rela­ tionship vvith the development of hypothyroidism p<0.05 .Gbnclusion: Due to high rates of subclinical or clinical hypothyroidism follovving combined therapy, thyroid func­ tions should be closely monitored in patients undergoing laryngectomy for T3 or T4 larynx cancers.

Keywords

• Combined modality therapy, laryngeal neoplasms/ surgery/radiotherapy, hypothyroidism/etiology, laryngectomy, radiotherapy/adverse effects, thyroid gland/immunology/radiation effect, thyroid function tests, thyroidectomy/adverse effects

Larenjektomi ve izleyen radyoterapinin tiroit fonksiyonları üzerine etkisi

Abstract

Amaç: T3-T4 larenks kanserleri nedeniyle larenjektomisırasında hemitiroidektomi-istmusektomi uygulanan veameliyat sonrasında radyoterapi gören olgularda hipotiroidi sıklığı arafltırıldı.Hastalar ve Yöntemler: Çalıflmaya T3-T4 larenks kanseri nedeniyle kombine tedavi gören 29 hasta alındı. Tüm olgulardaameliyat öncesi tiroit fonksiyon testleri normal idi. Radyoterapi sonrasında serum tiroit stimulan hormon sTSH , serbest triiyodotironin FT3 , serbest tiroksin FT4 düzeyleri üç ay arayla en az 12 ay süreyle izlendi. sTSH değeri yüksek, FT3ve/veya FT4 değerleri düflük olan olgular klinik hipotiroidi; sTSH değeri yüksek,FT3ve FT4 düzeyleri normal olgular subklinik hipotiroidi olarak değerlendirildi. Klinik veya subklinik hipotiroidi gelifliminin yafl ve radyoterapi dozu ile iliflkisi incelendi. İstatistiksel değerlendirmeler Student t- ve MannWhitney U testleriyle yapıldı.Bulgular: On iki olguda %41 kombine tedavi sonrasında tiroit fonksiyonları normal bulundu. On iki olguda %41 subklinik, befl olguda %18 klinik hipotiroidi geliflimi izlendi. Hipotiroidi geliflimi ile yafl arasında anlamlı iliflki görülmedi p>0.05 ; kullanılan radyoterapidozu ile tiroit fonksiyon bozukluğu arasında anlamlı iliflki gözlendi p

Keywords

• Kombine tedavi, larenjeal neoplazmlar/cerrahi/radyoterapi, hipotiroidi/etyoloji, larenjektomi, radyoterapi/yan etki, tiroit bezi/immünoloji/radyasyon etkisi, tiroitfonksiyon testleri, tiroidektomi/yan etki

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