Evaluation of Late Radiation Side Effects in Nasopharyngeal Cancer Patients

Abstract

The prolongation of survival in cases with nasopharynx cancer has made quality of life after treatment more important. The aim of this study is to consider late toxicity developing after treatment in order to maintain a high quality of life. Thirty-two patients receiving radiotherapy (RT) to the neck region 1-10 years ago due to nasopharyngeal carcinoma were included in the study. Neck ultrasonography (USG), thyroid function tests and dynamic brain magnetic resonance imaging (MRI) were carried out for carotid artery stenosis, hypothyroidism, and necrosis of the temporal lobe. Obtained data were analyzed with the SPSS 11.5. Intima-media thickness of below 60 Gy and above 60 Gy doses administered to the neck were similar. Intima-media thickness was greater in patients with a period longer than 5 years after RT than with a period shorter than 5 years (p< 0.001). Intima-media thicknesses of the patients above 40 years, with high cholesterol values, a history of smoking and hypertension were higher than those without them (p< 0.001). There was hypothyroidism in five (15%) of the 32 patients. Necrosis of the temporal lobe was not seen in any of the patients. Carotid artery stenosis after treatment depends more on the duration of the period after treatment and the patient's being in the age group when atherosclerotic risk factors are present than on the amount of dose administered.Keywords: Head-neck tumor, Radiotherapy, Late toxicity, Hypothyroidism ÖZET Nazofarenks kanserli Olgularda Rdyoterapiye Sekonder Geliflen Geç Yan Etkilerin De¤erlendirilmesiSon y›llarda nazofarenks kanserli olgularda yaflam süresinin artmas›, tedavi sonras› yaflam kalitesini ön plana ç›karm›flt›r. Bu grup hastalarda yaflam kalitesini yüksek tutmak için tedavi sonras› geliflen geç toksisitelerin irdelenmesi amaçlanm›flt›r. Nazofarenks kanseri nedeniyle boyun bölgesine 1-10 y›l önce radyoterapi (RT) alan 32 hasta çal›flmaya al›nm›flt›r. Hastalar›n karotis arter stenozu, hipotiroidi ve temporal lob nekrozu için boyun ultrasonogrofi (USG), tiroid fonksiyon testi ve dinamik beyin magnetik rezonans› (MR) yap›l-m›flt›r. Elde edilen veriler SPSS 11.5'de de¤erlendirilmifltir. Boyuna uygulanan 60 Gy alt› ile 60 Gy üzeri dozlardaki karotis intima-media kal›nl›¤› benzer ç›km›flt›r. RT sonras› geçen süre 5 y›ldan fazla olan hastalarda intima-media kal›nl›¤›, 5 y›ldan az olan hastalara oranla daha yüksek saptanm›flt›r (p< 0.001). 40 yafl üstü, kolesterol de¤eri yüksek, sigara ve hipertansiyon hikayesi olan hastalar›n damar kal›nl›¤› olmayanlardan daha yüksek ç›km›flt›r (p< 0.001). 32 hastadan 5'inde (%15) hipotiroidi saptanm›flt›r. Hastalar›n hiçbi-rinde temporal lob nekrozuna rastlanmam›flt›r. Tedavi sonras› karotis arter stenozu, uygulanan dozdan çok tedavi sonras› geçen sü-reye ve hastan›n aterosklerotik risk faktörlerini tafl›yaca¤› yafl grubunda olmas›na ba¤l›d›r. Bu grup hastalar›n takip ve kontrollerinde geç toksisitenin iyi flekilde de¤erlendirilmesi, aterosklerotik risk faktörlerine yönelik önleyici tedbirlerin al›nmas› ve tedavisine yönel...

Correlative study of dose to thyroid and incidence of subsequent dysfunction after head and neck radiation

“…Radiation-induced hypothyroidism incidence has been reported in 3% to 67% patients, although most authors will quote an incidence of between 20% and 40%. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] With the generalized use of intensitymodulated radiotherapy (IMRT) for head and neck cancer, the thyroid could be considered an organ at risk (OAR). Contouring to minimize thyroid dose without compromising tumor volume coverage could be beneficial.…”

“…A number of articles, including 1 meta-analysis, have attempted to investigate this. 4,5,7,9,11,14,17,18,20,[24][25][26] Some show thyroid side effects beginning as early as 6 to 12 Gy of radiation. 20,26 A secondary endpoint was to investigate the frequency of monitoring of thyroid function during the time period of this study.…”

“…Hypothyroidism, goiter, auto‐immune thyroiditis, and thyroid cancer are potential thyroid complications after radiation exposure. Radiation‐induced hypothyroidism incidence has been reported in 3% to 67% patients, although most authors will quote an incidence of between 20% and 40% . With the generalized use of intensity‐modulated radiotherapy (IMRT) for head and neck cancer, the thyroid could be considered an organ at risk (OAR).…”

“…The main purpose of this study was to determine the incidence of clinical and subclinical thyroid dysfunction after RT in a modern series. A number of articles, including 1 meta‐analysis, have attempted to investigate this . Some show thyroid side effects beginning as early as 6 to 12 Gy of radiation .…”