A Prospective study to determine the occurrence of hypothyroidism following treatment with radiation therapy in patients of head and neck carcinomas and factors influencing this

Suparna Kanti Pal, (2011) A Prospective study to determine the occurrence of hypothyroidism following treatment with radiation therapy in patients of head and neck carcinomas and factors influencing this. Masters thesis, Christian Medical College, Vellore.


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INTRODUCTION: Head and neck malignancies are one of the most common malignancies in world and India. A vast majority of patients of head and neck malignancies are treated with radiotherapy. There has been evidence that such radiation to the neck may result in post radiotherapy hypothyroidism. The incidence of post radiotherapy hypothyroidism in as reported in various literature varies from as low as 6% to as high as 68%. However, there is considerable debate regarding the incidence, influencing factors responsible, relationship with dose and time of development of the same. The available data for Indian patients, as found by Aich et al shows an incidence of 0.57% at 6 weeks and 21.8% at two years. Biochemical investigations are available for determination of hypothyroidism and supplementation with exogenous thyroxin is possible. Hypothyroidism manifests as fatigue, poor appetite, and temper fluctuation, leading to inability to meet social and familial roles. They also do effect on the professional and economic productivity of the patient and the family. This adds to the financial strain that results from the cost of care and loss of work days during the treatment period. Hypothyroidism also results in long term complications with respect to cardiac and general morbidity. Such morbidity in cancer survivors can be of immense physical, emotional, social and economic problems. Thus early detection and treatment of post radiotherapy hypothyroidism can result in avoidance of such complications and help in improving the quality of life. Most of the guidelines have been developed on basis of the western data. The applicability of the same, to Indian population, is not well defined, especially, in view of heterogeneity of data, originating from different population of the world. This not only includes the incidence but also time of occurrence of hypothyroidism post radiotherapy. This study is an endeavor to determine the incidence, associated factors in development of hypothyroidism including the temporal association of the incidence with respect to the population from the Indian subcontinent. AIMS OF THE STUDY: 1. To determine the incidence of clinical and subclinical hypothyroidism in patients undergoing radiation therapy for head and neck carcinomas. 2. To determine the factors influencing the occurrence of hypothyroidism. 3. To evaluate impact on quality of life. MATERIALS AND METHODS: Inclusion criteria: 1. Adult patients[ more than 18 years of age] with non-metastatic Head & Neck carcinoma, without any intracranial extension, of the following sites- a. Nasopharynx, b. Sinonasal cavity, c. Oropharynx, d. Oral cavity, e. Hypopharynx, f. Larynx, g. CUP [Carcinoma of unknown primary], 2. Patients receiving radiotherapy(>45 Gy) as part of treatment, 3. Radiation field extending to lower neck , unilateral or bilateral, 4. Performance score- 0 to 2. Exclusion criteria: 1. Known to have hypothyroidism: a) At the time of screening, b) The history of hypothyroidism in the past, for which he/she is currently on supplements. [Hypothyroidism was defined as TSH more than the maximum of the normal range, or TSH >4.5 micro IU/ml]. CONCLUSION: 1. Hypothyroidism at baseline evaluation was 11% and the incidence of secondary hypothyroidism post radiotherapy was 13.51% -- 2. Surface dose measurements as described in the earlier literature did not correlate with clinical outcome and should be looked into in the light of 3D organ imaging and dose volume relationships in the era of modern radiotherapy. 3. The significant clinical symptoms of secondary hypothyroidism are cold intolerance and weight gain seen as early as six weeks. 4. Iatrogenic hypothyroidism occurred over a variable point of time during the follow up period as early as 6 weeks and at 19 weeks of completion of radiotherapy. 5. Females appeared to be more prone to develop post radiotherapy hypothyroidism. 6. Those patients with TSH levels more than 3 m IU/ml at base line were found to be more prone to develop secondary hypothyroidism. 7. Hypothyrodism is a significant comorbid association at presentation which can worsen with radiotherapy and early institution of treatment results in improvement of quality of life. In view of this, a baseline and follow up TSH as routine should be incorporated in the management schedule. This simple biochemical screening is a cost effective strategy to improve the quality of life in head and neck cancer.

Item Type: Thesis (Masters)
Uncontrolled Keywords: occurrence, hypothyroidism, radiation therapy, head and neck carcinomas, factors influencing.
Subjects: MEDICAL > Radio Therapy
Depositing User: Subramani R
Date Deposited: 23 Mar 2020 15:42
Last Modified: 23 Mar 2020 15:42
URI: http://repository-tnmgrmu.ac.in/id/eprint/12421

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