Long-term incidence of hypothyroidism after radiotherapy in patients with head-and-neck cancer

Latissimus dorsi myocutaneous free flap for the laryngopharyngectomy defect

BACKGROUND

Partial or total laryngopharyngectomy defects have traditionally been reconstructed using the radial forearm, anterolateral thigh, or jejunal free flaps. The latissimus dorsi myocutaneous free flap (LDMFF) is an option for high-risk patients with complex laryngopharyngeal ± cutaneous neck defects.

METHODS

Retrospective single-surgeon case series from 2017 to 2022. Outcomes were assessed at both the back donor site and head and neck.

RESULTS

Twenty-four patients were identified. Flap survival was 100%. There was 1 (4.2%) pharyngocutaneous fistula and 2 (8.3%) tracheo-esophageal peristomal fistulas. At last follow-up, 17 (71%) were sustaining weight on oral intake, and 7 (29%) were G-tube dependent with 4 of these able to do some type of oral intake. Seven (29.2%) had post-operative stricture/stenosis requiring dilation. There were only minor donor site complications, all managed conservatively.

CONCLUSIONS

The LDMFF can be a robust reconstructive option, particularly for radiated high-risk patients with complex pharyngeal defects, including skin.

Extent of thyroidectomy and paratracheal lymph node dissection in total pharyngolaryngectomy for pyriform sinus cancer, and recurrence, survival, and postoperative hypoparathyroidism: A multicenter retrospective study

BACKGROUND

Total pharyngolaryngectomy (TPL) is standard treatment for hypopharyngeal cancer. However, extensive thyroidectomy and paratracheal nodal dissection (PTND) can cause hypoparathyroidism. We sought to determine the optimum extent of resection.

METHODS

We analyzed the clinicopathological information of 161 pyriform sinus cancer patients undergoing TPL from 25 Japanese institutions. Rates of recurrence and risk factors for hypoparathyroidism, as well as incidence of pathological contralateral level VI nodal metastasis and stomal recurrence, were investigated.

RESULTS

The extent of thyroidectomy and nodal dissection were not independent risk factors for recurrence. Incidences of contralateral level VI nodal involvement and stomal recurrence were 1.8% and 1.2%, respectively. Patients undergoing hemithyroidectomy/ipsilateral PTND did not develop stomal recurrence and had the lowest incidence of hypoparathyroidism. Prognosis in patients without tracheostomy prior to hemithyroidectomy/ipsilateral PTND was comparable to that with more extensive resections.

CONCLUSIONS

Hemithyroidectomy/ipsilateral PTND may be sufficient for pyriform sinus cancer cases without tracheostomy.

[Prospective evaluation of radiation-induced thyroid disorders after breast and supraclavicular irradiation]

PURPOSE

The thyroid is an endocrine gland playing a major role in metabolism and development by the secretion of T4 and T3 thyroid hormones. Due to its anatomical position, it is often included in the target volume for the irradiation of certain tumours and thus receives significant doses (10 to 80Gy). The treatment of breast cancer requires in most cases a breast irradiation associated or not with a lymph node irradiation. The aim of our study was to investigate prospectively the frequency of thyroid disorders in patients with breast cancer treated by radiation, with or without irradiation of the supra- and subclavicular lymph nodes.

MATERIAL AND METHODS

This prospective multicentre study (institut Godinot, institut de cancérologie Strasbourg Europe and institut de cancérologie de Lorraine) concerned adult patients with non-metastatic breast carcinoma treated by adjuvant irradiation. They were included in a non-randomized way between February 2013 and June 2015 and divided into two groups according to treatment: (i) breast radiotherapy associated with irradiation of the supra- and subclavicular lymph nodes (group 1), or (ii) breast irradiation alone (group 2). The dose - volume histogram of the thyroid was systematically edited by the physics department. Each patient had a consultation with an endocrinologist at the beginning of the treatment and was monitored by blood analyses including TSH, T4L, antithyroglobulin and antiperoxidase antibodies every 6 months until the 60th month after the end of radiotherapy. Data were described by numbers and percentages for qualitative variables; by means, medians, standard deviation and ranges for quantitative variables. Statistical associations were tested by Chi2, Fisher's, Student's, or analysis of variance tests depending on the conditions of application. Survival analyses were performed by log rank tests and Cox models.

RESULTS

This study initially included 500 patients, 245 in group 1 and 252 in group 2 (three patients were later excluded for false inclusion). Thyroid abnormalities occurred in 76 patients, representing an incidence of 15.3%. The mean time of the first occurrence of thyroid disorders was 24.3 months. It was more frequent in group 1 with a prevalence of 19.2% against 11.5% in group 2 (P=0.01745). A maximal radiation dose delivered to the thyroid gland greater than 20Gy (odds ratio [OR]: 1.82; P=0.018) or 30Gy (OR: 1.89; P=0.013) was significantly associated with a higher incidence of thyroid disorders, as was a mean dose greater than 30Gy (OR: 5.69; P=0.049). A percentage of thyroid volume receiving 30Gy (V30) greater than 50% (P=0.006) or greater than 62.5% (P=0.021) was significantly associated with an increased incidence of thyroid disorder and more precisely, hypothyroidism (P=0.0007). In multivariate analysis, no factor associated with the occurrence of thyroid disorder was identified. However, in the subgroup analysis concerning group 1 (receiving supraclavicular irradiation), a maximal radiation dose greater than 30Gy appeared to be a risk factor for the occurrence of thyroid disorders (P=0.040).

CONCLUSION

Thyroid disorder, and in particular hypothyroidism, may be a late side effect of locoregional breast radiotherapy. Patients receiving this treatment should have a biological monitoring of thyroid function.

Radiation-Induced Hypothyroidism in Patients With Breast Cancer After Hypofractionated Radiation Therapy: A Prospective Cohort Study

PURPOSE

Our objective was to assess the incidence and risk factors of radiation-induced hypothyroidism (RHT) after adjuvant hypofractionated radiation therapy (RT) in patients with breast cancer.

METHODS AND MATERIALS

Eligible patients with breast cancer who were treated with hypofractionated RT were prospectively evaluated. Thyroid function tests were performed before and at regular times after RT. RHT was defined as twice elevated serum thyroid-stimulating hormone (TSH) with decreased or normal free thyroxin after RT. The patient, tumor, and treatment factors were evaluated for possible associations with the risk of RHT.

RESULTS

Five hundred patients were analyzed. All patients underwent chest wall/breast with or without regional nodal irradiation. Among them, 369 (73.8%) patients received supraclavicular nodal radiation (SCRT). Eighty-two (16.4%) patients had elevated TSH before RT. At a median follow-up of 21.9 months, 131 (26.2%) patients developed RHT, and 59 (11.8%) patients received thyroid hormone-replacement therapy. Patients with SCRT had a significantly increased 2-year cumulative incidence of RHT compared with patients without SCRT (31.5% and 11.4%, P<.001). The peak incidence of RHT occurred around 6 to 12 months after RT. Multivariate analysis revealed that elevated baseline TSH and increased thyroid mean dose (Dmean) were independent risk factors for developing RHT. After adjusted for baseline TSH, there was a nonlinear relationship between thyroid Dmean and the risk of RHT. Dmean >21 Gy was the threshold value for predicting RHT (hazard ratio, 2.2; P<.001).

CONCLUSIONS

The incidence of RHT was high in patients with breast cancer. Thyroid function test should be started no later than 6 months after RT. We recommend that the Dmean of the thyroid should be kept lower than 21 Gy for hypofractionated RT.

A prospective clinical study to assess primary hypothyroidism in head and neck cancer patients treated with external beam radiotherapy

PURPOSE

Head and neck cancers are treated by multimodality methods like surgery, radiotherapy, and chemotherapy. Hypothyroidism is one of the late side effects of radiation to the neck. The main aim of the study was to assess the incidence of primary hypothyroidism in patients with head and neck cancers, who received therapeutic external beam radiation; to evaluate the time duration and the total dose of radiation for the development of hypothyroidism.

MATERIALS AND METHODS

A prospective observational study was conducted in our institute on 200 patients from December 2018 to April 2020 with head and neck cancers, which were proven histopathologically. They received external beam radiation using Cobalt 60 or Linear accelerator. A thyroid function test was done in patients after 3 months and 6 months of completion of radiotherapy.

RESULTS

The incidence of hypothyroidism was 8% after 3 months (P value = 0.0088) post radiation and increased to 14% after 6 months (P value = 0.0024). Of the patients who developed hypothyroidism, a maximum number of cases (24; 86%) were given 60 Gy radiation dose, three (10%) were given 40-59 Gy, and one (3%) was given up to 40 Gy as the mean dose of radiation to the lower neck. A P value of 0.750 was not significant; hence, a dose of radiation was not a significant factor. The patients treated with the two-dimensional (2-D) technique (50%) had a higher incidence of hypothyroidism than the patients treated with three-dimensional conformal radiation therapy (3D-CRT) (14.8%) and intensity-modulated radiation therapy (IMRT) (9%). The use of concurrent cisplatin was not a significant factor for hypothyroidism (P value = 1).

CONCLUSION

Thyroid function test should be done in patients who received therapeutic external beam radiation to the neck at baseline and periodically. The early detection and treatment can prevent complications of long-term thyroid hypofunction like hypercholesterolemia, cardiovascular side effects, menstrual irregularities, infertility, peripheral neuropathy, depression, and myxoedema.

Evaluation of the Radiobiological Models predicting the Radiation-Induced Hypothyroidism in the Partially Irradiated Thyroid Gland of Patients with Breast Cancer

Background: Radiation-induced hypothyroidism (RHT) is one of the side effects that might have an impact on the quality of life of patients with breast cancer treated with radiotherapy. Objectives: The aim of the current study was to evaluate the performances of the Lyman-Kutcher-Burman (LKB) and Log-Logistic models in the prediction of hypothyroidism (HT) as well as the estimation of the model parameters for the incidence of RHT among patients with breast cancer. Methods: Fifty-two patients treated with radiation therapy (RT) for breast cancer were prospectively evaluated. Patients' serum samples [tri-iodothyronine, thyroxine, thyroid-stimulating hormone (TSH), free triiodothyronine, and free thyroxine] were measured before RT and also at a regular time interval until 1 year after the completion of RT. For each patient, dose-volume histograms (DVHs) of the thyroid gland were derived from their treatment planning dataset. Patients whose TSH levels were higher than normal with a decrease in FT4 levels were considered as cases with RHT. The LKB and Log-Logistic radiobiological models were evaluated by comparing them with the resultant follow-up data. The parameters for radiobiological models have been deduced by fitting the models to the follow-up data. The models were fitted in a Bayesian setting and compared according to the widely applicable information criterion (WAIC). Results: Twenty-one (40%) patients developed RHT at a follow-up of 1 year after the end of radiation treatment. The fitted values of D50 for the LKB and Log-Logistic models were 37.71 and 25.50 Gy, respectively for the partially irradiated thyroid of patients with breast cancer. The mean time to the incidence of RHT was obtained at 6.7 months in the studied group. Conclusions: A volumetric effect was found for the thyroid gland in the implemented normal tissue complication probability models. Compared to the follow-up data, the Log-Logistic model was ranked as the best model for predicting the rate of RHT in patients with breast cancer.

Risk factors associated with patient-reported fatigue among long-term oropharyngeal carcinoma survivors

BACKGROUND

The study objective is to identify risk factors associated with fatigue among long-term OPC survivors.

METHODS

This cross-sectional study included disease-free OPC survivors treated curatively between 2000 and 2013 who were surveyed from September 2015 to July 2016. The outcome variable was patient-reported fatigue. Multivariable logistic regression was used to identify factors associated with moderate to severe fatigue.

RESULTS

Among 863 OPC survivors, 17.4% reported moderate to severe fatigue. Self-reported thyroid problems (OR: 2.01; p = 0.003), current cigarette smoking at time of survey (OR: 3.85; p = 0.001), late lower cranial neuropathy (OR: 3.44; p = 0.002), and female sex (OR: 1.91; p = 0.010) were concurrent risk factors of reporting moderate to severe fatigue. Ipsilateral intensity-modulated radiotherapy (OR: 0.18; p = 0.014) was associated with lower risk of reporting moderate to severe fatigue.

CONCLUSIONS

Our study identified thyroid problems, smoking, and late lower cranial neuropathy as associated with moderate to severe fatigue. These findings should be further validated in prospective studies to address fatigue among OPC survivors.

Imaging of Complications of Chemoradiation

Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). These may be difficult to distinguish from tumor recurrence on imaging, and may necessitate the use of advanced MRI and molecular imaging techniques to reach the correct diagnosis. Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.

Functional and biochemical changes in the thyroid gland following exposure to therapeutic doses of external beam radiotherapy in the head-and-neck cancer patients

Context

Majority of the head-and-neck cancers are locoregionally advanced at the time of diagnosis. Hence, radiotherapy (RT) portals will invariably cover the whole neck and thus, the thyroid gland which may lead to its dysfunction.

Aims

The purpose of this study is to identify the functional and biochemical changes in the thyroid gland following RT to the neck using single-photon emission computed tomography-computed tomography (SPECT-CT) and thyroid function tests (TFTs).

Subjects and Methods

In this prospective study, 45 patients of the head-and-neck cancer, receiving RT with or without chemotherapy were investigated. Baseline TFTs and thyroid scans (on SPECT-CT) were done, and the same were repeated at the completion of RT, at 3 and 6 months.

Results

All patients received a minimum of 30 Gy to the whole neck. Baseline TFTs and thyroid scans were normal. None of them developed hypothyroidism clinical or subclinical (C/S) at the completion of RT. Six patients developed hypothyroidism (four subclinical, two clinical) at 3 months of the completion of treatment. At 6 months of follow-up 14 patients (31.1%) developed hypothyroidism (ten subclinical, four clinical) with P≤ 0.01. All patients having clinical or subclinical hypothyroidism had decreased uptake on thyroid scan. Patients having decreased uptake on thyroid scan only, with normal TFTs and no symptoms of hypothyroidism were zero at the completion of RT, 1 at 3 months follow-up, and seven at 6 months follow-up.

Conclusions

Hypothyroidism (C/S) is an under-recognized but significant complication of therapeutic doses of RT to the neck. In our study, we recognized hypothyroidism as early as 3 months following the completion of RT. Hence, tests to evaluate functional and biochemical changes in the thyroid gland should be instituted as early as 3 months following RT.

Volumetric-modulated arc therapy in craniospinal irradiation: a dosimetric analysis of acuros XB and analytical anisotropic algorithm comparing flattened and flattening filter-free beams with different energies

Aim:

To compare the dosimetric performance of flattening filter-free (FFF) beam and flattened beams (FBs) utilising volumetric-modulated arc therapy (VMAT) for craniospinal irradiation (CSI) planning.

Materials and Methods:

Five medulloblastoma patients were randomly selected retrospectively and 40 plans were generated. The dose prescription to the planning target volume (PTV) was 36 Gy in 20 fractions. VMAT plans were created using 6 MV and 10 MV FB and FFF beam. Final dose calculations were performed using Acuros XB (AXB) and analytical anisotropic algorithm (AAA). Dosimetric parameters such as D98%, D95%, D50%, V110%, conformity index (CI), homogeneity index (HI), low-grade dose index, high-grade dose index, dose to the organ at risks (OARs) and normal tissue mean dose were noted. The effect of low-dose volume on normal tissue was also analysed.

Results:

The 6 MV and 10 MV flattened and FFF beam plan generates similar target coverage, and a significant difference was observed in the HI and CI. FFF beam plan produces lower doses in some of the OARs as compared to FB. Significant differences were also noted in monitor unit (MU), body-PTV mean dose and low-dose spillage regions (1–10 Gy) outside the PTV. In our study, 6 MV and 10 MV FFF beam beams need 23–25% more MUs to achieve planning goals when compared to FBs. The increased MUs in FFF plan decreases the body-PTV mean dose (0·07–0·09 Gy in 6 MV FFF and 0·31 Gy in 10 MV FFF in both algorithms) when compared to FB plans.

Conclusion:

FFF beams generate a highly conformal and homogenous plan in CSI cases. FFF beam plan reduced the non-tumour dose and will aid in reducing the probability of second malignancies.

Hypothyroidism in Head and Neck Squamous Cell Carcinoma Patients Receiving Radiotherapy With or Without Immune Checkpoint Inhibitors

OBJECTIVES/HYPOTHESIS

Hypothyroidism is a relatively common complication of head and neck squamous cell carcinoma (HNSCC) treatment. The objective of this study was to determine whether the addition of programmed death ligand-1 (PD-1) or programmed death ligand-1 (PD-L1) inhibition (anti-PD-1/PD-L1 therapy) to standard treatment increases the risk of hypothyroidism in HNSCC.

STUDY DESIGN

Retrospective Cohort.

METHODS

This is a retrospective, single institutional cohort study. Patients who received radiotherapy (RT) for HNSCC were identified in the electronic medical record. Patient factors collected include age, sex, body mass index (BMI), smoking status, alcohol use, Charlson comorbidity index, and HNSCC treatment records. The rate of hypothyroidism for patients with HNSCC receiving RT (+/- chemotherapy and surgery) (RT group, n = 101) was compared to that of HNSCC patients receiving RT (+/- chemotherapy and surgery) + anti-PD-1/PD-L1 therapy, either concurrently or after RT (RT + anti-PD-1/PD-L1 group, n = 38).

RESULTS

There was no significant difference in the rate of clinical or subclinical hypothyroidism between the two groups. Multinomial logistic regression found no significant difference in hypothyroidism based on age, sex, or BMI.

CONCLUSIONS

The addition of anti-PD-1/PD-L1 therapy to standard HNSCC treatment does not significantly increase the risk of developing hypothyroidism.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E2413-E2419, 2021.

Intestinal Dysbiosis and Development of Cardiometabolic Disorders in Childhood Cancer Survivors: A Critical Review

Significance: Survivors of pediatric cancers have a high risk of developing side effects after the end of their treatments. Many potential factors have been associated with the onset of cardiometabolic disorders (CMD), including cancer disease itself, chemotherapy, hormonal treatment, radiotherapy, and genetics. However, the precise etiology and underlying mechanisms of these long-term complications are poorly understood. Recent Advances: Greater awareness is currently paid to the role of microbiota in the emergence of cancers and modulation of cancer therapies in both children and adults. Alterations in the composition and diversity of intestinal microbiota can clearly influence tumor development and progression as well as immune responses and clinical output. As dysbiosis is closely linked to the development of host metabolic diseases, including obesity, metabolic syndrome, type 2 diabetes, and non-alcoholic fatty liver disease, it may increase the risk of CMD in cancer populations. Critical Issues: Only limited studies targeting the profile of intestinal dysbiosis before and after cancer treatment have been conducted. Further, the exact contribution of intestinal dysbiosis to the development of CMD in cancer survivors is poorly appreciated. This review intends to clarify the influence of gut microbiota on CMD in childhood cancer survivors, elucidate the potential mechanisms, and evaluate the latest research on the interplay between diet/food supplement, microbiota, and cancer-related CMD. Future Directions: The implication of intestinal dysbiosis in late metabolic complications of childhood cancer survivors should be clarified. Intervention strategies could be developed to reduce the risk of survivors to CMD. Antioxid. Redox Signal. 34, 223-251.

Research progress of radiation-induced hypothyroidism in head and neck cancer

This paper reviews the factors related to hypothyroidism after radiotherapy in patients with head and neck cancer to facilitate the prevention of radiation-induced hypothyroidism and reduce its incidence. Hypothyroidism is a common complication after radiotherapy in patients with head and neck cancer, wherein the higher the radiation dose to the thyroid and pituitary gland, the higher the incidence of hypothyroidism. With prolonged follow-up time, the incidence of hypothyroidism gradually increases. Intensity modulated radiotherapy should limit the dose to the thyroid, which would reduce the incidence of hypothyroidism. In addition, the risk factors for hypothyroidism include small thyroid volume size, female sex, and previous neck surgery. The incidence of radiation-induced hypothyroidism in head and neck cancer is related to the radiation dose, radiotherapy technique, thyroid volume, sex, and age. A prospective, large sample and long-term follow-up study should be carried out to establish a model of normal tissue complications that are likely to be related to radiation-induced hypothyroidism.

Does thyroid-sparing total laryngectomy decrease the risk of hypothyroidism?

BACKGROUND

Thyroid lobectomy is recommended with total laryngectomy for laryngeal cancer in the National Comprehensive Cancer Network ('NCCN') guidelines. However, it is associated with a 32-89 per cent risk of hypothyroidism, with or without adjuvant radiotherapy.

OBJECTIVE

The study aimed to determine whether preserving the whole thyroid, compared to a single lobe, does indeed significantly lower the incidence of hypothyroidism in the setting of total laryngectomy.

METHOD

A retrospective study was conducted at Groote Schuur Hospital in Cape Town, South Africa.

RESULTS

Eighty-four patients met the inclusion criteria. The overall incidence of hypothyroidism was 45.2 per cent. The incidence of hypothyroidism was significantly reduced in patients who underwent thyroid-sparing total laryngectomy compared to hemithyroidectomy (p = 0.037). Adjuvant radiotherapy was associated with a higher incidence of hypothyroidism (p = 0.001).

CONCLUSION

Thyroid-preserving laryngectomy should be advocated in carefully selected patients with advanced laryngeal carcinoma, as it reduces the incidence of hypothyroidism.

Is nasopharyngeal carcinoma in young patients a distinct clinical entity? A single-institution case matched analysis in the era of intensity-modulated radiotherapy

OBJECTIVES

To compare the treatment outcomes between young and adult patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT).

MATERIALS AND METHODS

We conducted a retrospective case-matched analysis of all patients with non-metastatic NPC ≤20 years treated in our institution between January 2010 and July 2016. Adult patients ≥35 years treated over the same time period were included and matched at a ratio of 1:1 according to N classification, T classification, treatment modality, year of diagnosis, and gender. Survival outcomes and late toxicities were compared between the two groups.

RESULTS

Overall 112 young patients with NPC were included, and 112 out of 3105 consecutive patients with NPC aged ≥35 years were matched. The 5-year overall survival (OS), progression-free survival, locoregional control and distant control of young and control cohorts were 89.1% vs. 79.3% (p = 0.03), 80.3% vs. 67.0% (p = 0.02), 96.4% vs. 84.3% (p < 0.01), and 82.9% vs. 82.8% (p = 0.94), respectively. Multi-variate analysis showed that age ≤20 years was the only significant factor predicting for better OS (HR = 0.5, CI 0.3-0.97, p = 0.04). A trend of higher rate of hypothyroidism (grade 1-2) was observed in the young cohort (67.9% vs. 46.2%, p = 0.08).

CONCLUSION

Young patients with NPC treated with modern multimodality therapy have better survival outcomes. Age was an independent favorable prognostic factor for NPC in the IMRT era. Further prospective studies are needed to establish optimal management for the young population to minimize and manage long-term side-effects without compromising survival.

Thyroid Dysfunction Following Management of Non-thyroid Head and Neck Cancers

Head and neck cancers are one of the commonest malignancies in India. Majority of cases of head and neck malignancy undergo chemoradiation with or without surgery. Thyroid bears the brunt in terms of either excision or the gland tends to get irradiated and fibrosed. In either scenario the functionality of gland is lost leading to hypothyroidism and other clinical manifestations. It tends to get subclinical and goes unnoticed. To identify the occurrence of clinical and subclinical hypothyroidism among head and neck cancer patients receiving radiation to the neck and to justify routine use of thyroid function tests during follow up. It was a prospective non randomized control study of 100 patients of head and neck cancer receiving radiotherapy for duration of 1 year. Thyroid stimulating hormone and T3 and T4 estimations were done at baseline and at 3 and 9 months following radiotherapy. Out of 100 patients, 72 (72%) were males and 28 (28%) were females. All the patients received radiation to the neck to a dose of > 30 Gy. 35 patients received concurrent chemotherapy. 11 patients were found to have subclinical hypothyroidism while 32 patients developed significant clinical hypothyroidism (P value of 0.001). Thus a total of 43 patients developed radiation induced hypothyroidism. 20 of the 32 patients who developed clinical hypothyroidism were in the age group of 41-50 years. 11 of 32 patients who developed clinical hypothyroidism received chemoradiation while rest 21 received radiotherapy alone. Mean period for developing radiation induced hypothyroidism was 4.5 months. Hypothyrodism (clinical or subclinical) is an under recognised morbidity of external radiation to the neck which is seen following a minimum dose of 30 Gy to the neck. Recognising hypothyroidism (clinical or subclinical) early and treating it prevents thyroid dysfunction related complications. Hence, thyroid function tests should be made routine during follow up in all patients undergoing radiotherapy.

Dose-volume derived nomogram as a reliable predictor of radiotherapy-induced hypothyroidism in head and neck cancer patients

Background

The aim of this study was to determine the possible predictive value of various dosimetric parameters on the development of hypothyroidism (HT) in patients with head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy.

Patients and methods

This study included 156 patients with HNSCC who were treated with (chemo)radiotherapy in a primary or postoperative setting between August 2012 and September 2017. Dose-volume parameters as well as V10 toV70, D02 to D98, and the VS10 to VS70 were evaluated. The patients’ hormone status was regularly assessed during follow-up. A nomogram (score) was constructed, and the Kaplan-Maier curves and Log-Rank test were used to demonstrate the difference in incidence of HT between cut-off values of specific variables.

Results

After a median follow-up of 23.0 (12.0–38.5) months, 70 (44.9%) patients developed HT. In univariate analysis, VS65, Dmin, V50, and total thyroid volume (TTV) had the highest accuracy in predicting HT. In a multivariate model, HT was associated with lower TTV (OR 0.31, 95% CI 0.11–0.87, P = 0.026) and Dmin (OR 9.83, 95% CI 1.89–108.08, P = 0.042). Hypothyroidism risk score (HRS) was constructed as a regression equation and comprised TTV and Dmin. HRS had an AUC of 0.709 (95% CI 0.627–0.791). HT occurred in 13 (20.0%) patients with a score < 7.1 and in 57 (62.6%) patients with a score > 7.1.

Conclusions

The dose volume parameters VS65, Dmin, V50, and TTV had the highest accuracy in predicting HT. The HRS may be a useful tool in detecting patients with high risk for radiation-induced hypothyroidism.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Subsequent thyroid disorders associated with treatment strategy in head and neck cancer patients: a nationwide cohort study

BACKGROUND

We investigated the risk of thyroid disorders, namely hypothyroidism, thyrotoxicosis and thyroiditis, in head and neck cancer patients undergoing multimodal treatment.

METHODS

A cohort study design using Taiwan's National Health Insurance Research Database was used to assess head and neck cancer patients over 20 years old. The cohort was divided into one group who underwent primary tumor excision only (PTE) and another with additional neck dissection (PTE + ND). The tumor sites were stratified to estimate the tumor-site-specific risk of thyroid disorders. The effect of subsequent resurgery, radiotherapy (RT), chemotherapy (CT), and concomitant (CCRT) or sequential chemoradiation therapy (sequential CT+ RT) on the risk of thyroid disorders was explored.

RESULTS

For 1999-2012, 7460 patients who underwent PTE + ND and 3730 who underwent PTE were enrolled and followed-up until the end of 2013. There were 122 and 50 patients in the two groups, respectively, who developed thyroid disorders, with no statistical difference between the groups. Patients with hypopharyngeal, oropharyngeal, or laryngeal cancer in the PTE + ND group had a higher risk of thyroid disorders (adjusted HR: 1.50, 95% CI: 0.67-3.38) than those in the PTE group when adjusted for covariates and mortality. Patients who underwent subsequent RT (adjusted HR: 3.64, 95% CI: 1.05-2.77) and CCRT (adjusted HR: 1.70, 95% CI: 1.05-2.77) after PTE + ND had a significantly higher risk of thyroid disorders.

CONCLUSION

RT results in a major risk of subsequent thyroid disorders, and ND may exacerbate this effect. Physicians should monitor thyroid function from two years after treatment initiation, especially in patients who undergo ND and subsequent RT.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

A review on the dosimetrical and radiobiological prediction of radiation-induced hypothyroidism in radiation therapy of head-and-neck cancer, breast cancer, and Hodgkin’s lymphoma survivors

A review on the radiobiological modeling of radiation-induced hypothyroidism after radiation therapy of head-and-neck cancers, breast cancer, and Hodgkin’s lymphoma is presented. The current review is based on data relating to dose-volume constrains and normal tissue complication probability (NTCP) as a function of either radiobiological or (pre)treatment-clinical parameters. Also, these data were explored in order to provide more helpful criteria for radiobiological optimization of treatment plans involving thyroid gland as a critical normal organ.

Evaluating dose to thyroid gland in women with breast cancer during radiotherapy with different radiation energies at supraclavicular fossa region

Background and aim

During the treatment of breast cancer, radiotherapy to the supraclavicular fossa region results in absorption of radiation by the thyroid gland and consequently leads to hypothyroidism in 40% of patients. The aim of this study was to compare thyroid gland radiation absorption during radiotherapy with different anterioposterior beam radiation of 6–15 and 15–15 MV photon beam energies.

Materials and methods

In total, 29 patients with breast cancer were recruited to this study. Adjuvant radiotherapy with a total dose of 50 Gy was performed for each participant. Thyroid gland dosimetric measurements were evaluated including, mean dose, minimum and maximum dose, and V20, V30, V40 and V50 (percentage of thyroid volume receiving ≥20, ≥30, ≥40 and ≥50 Gy, respectively). The irradiation delivered doses were measured using Prowess Panther treatment planning system (Version 5.5). All data were evaluated using SPSS software.

Results

In total, 29 subjects with mean age of 53·4±9·4 were studied. According to the obtained results, at 15–15 MV energies, a significantly lower dose was absorbed by the thyroid gland, was observed in contrast to their counterparts who were treated with 6–15 MV photon beam energies.

Findings

Using 15–15 MV photon beam energies field can significantly reduce the absorbed dose to the thyroid gland and consequently can reduce the risk of developing hypothyroidism in breast cancer patients treated with radiotherapy.

THYROID DISEASES AMONG ATOMIC BOMB SURVIVORS

Systematic epidemiological studies of Hiroshima and Nagasaki atomic bomb survivors have made substantial contributions to the understanding of radiation effects on human health. A recent study of atomic bomb survivors reported that an increased risk of thyroid cancer associated with childhood exposure might have persisted for more than 50 years after exposure. In analyses of non-cancer thyroid diseases, several cross-sectional studies, including the latest study focusing on survivors exposed in childhood, suggested that the risk of thyroid nodules increased, while risks of thyroid dysfunction and autoimmunity were not apparent several decades after radiation exposure. However, careful interpretations are needed because only limited data from cross-sectional studies are available. Further longitudinal studies are necessary to improve our understanding of the effect of radiation on the thyroid and its function.

A dosimetric study on radiation-induced hypothyroidism following intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma

The objective of the present study was to investigate the association between thyroid gland-dosimetric parameters and hypothyroidism induced by intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma (NPC). A total of 52 patients with NPC treated in the Department of Radiation Oncology of The Affiliated Hospital of Xuzhou Medical University, from May 2008 to December 2016 were retrospectively enrolled in the present study and divided into two groups based on thyroid function: The euthyroid and hypothyroid groups. The association between hypothyroidism and clinical or dosimetric parameters were analyzed. Females had a significantly increased probability of suffering from radiation-induced hypothyroidism (RIHT), compared with males (P=0.010). The occurrence of RIHT was significantly negatively associated with thyroid volume prior to radiotherapy (P=0.048). Furthermore, the mean dose (Dmean) and V50 in the hypothyroidism group were significantly increased, compared with the euthyroidism group (P=0.017 and P=0.023, respectively). During the treatment optimization period, dose constraints associated with the thyroid gland demonstrated a significantly protective effect on thyroid function compared with the unconstrained group (P=0.034). According to the receiver operating characteristic curves, the threshold value was 5,160 cGy for Dmean and 54.5% for V50. The 3-year cumulative incidence of RIHT was 67.8% when the Dmean value was >5,160 cGy and 44.6% when the Dmean was <5,160 cGy (log rank test, P=0.036). Furthermore, the 3-year cumulative incidence was 66.1% when the V50 was >54.5%, and 29.9% when the V50 was <54.5% (log rank test, P=0.025). In conclusion, RIHT is associated with radiation dose, particularly with Dmean and V50 of the thyroid gland. Dose constraints associated with the thyroid gland significantly reduced the incidence of hypothyroidism compared with the unconstrained group.

Validation of previously reported predictors for radiation-induced hypothyroidism in nasopharyngeal cancer patients treated with intensity-modulated radiation therapy, a post hoc analysis from a Phase III randomized trial

This study aimed to validate previously reported dosimetric parameters, including thyroid volume, mean dose, and percentage thyroid volume, receiving at least 40, 45 and 50 Gy (V40, V45 and V50), absolute thyroid volume spared (VS) from 45, 50 and 60 Gy (VS45, VS50 and VS60), and clinical factors affecting the development of radiation-induced hypothyroidism (RHT). A post hoc analysis was performed in 178 euthyroid nasopharyngeal cancer (NPC) patients from a Phase III study comparing sequential versus simultaneous-integrated boost intensity-modulated radiation therapy. RHT was determined by increased thyroid-stimulating hormone (TSH) with or without reduced free thyroxin, regardless of symptoms. The median follow-up time was 42.5 months. The 1-, 2- and 3-year freedom from RHT rates were 78.4%, 56.4% and 43.4%, respectively. The median latency period was 21 months. The thyroid gland received a median mean dose of 53.5 Gy. Female gender, smaller thyroid volume, higher pretreatment TSH level (≥1.55 μU/ml) and VS60 < 10 cm3 were significantly associated with RHT in univariate analyses. Only pretreatment TSH ≥ 1.55 μU/ml and VS60 < 10 cm3 were significant predictors in multivariate analysis. Our results suggested that patients with pretreatment TSH ≥ 1.55 μU/ml should be cautious about the risk of RHT. The VS60 ≥ 10 cm3 is recommended for treatment planning.

Evaluation of thyroid gland as an organ at risk after breast cancer radiotherapy: a systematic review and meta-analysis

BACKGROUND

Radiotherapy can often lead to thyroid dysfunction. Some studies demonstrated that treatment of breast cancer by RT can expose thyroid gland to high doses of radiation. The aim of this systematic review is to evaluate consideration of thyroid gland as an organ at risk.

METHODS

In this systematic review and meta-analysis to select initial studies, a comprehensive search by two independent reviewers was performed. Electronical databases following: Web of Science, Google Scholar, Scopus, PubMed, Elsevier, Embase, ProQuest and Persian databases such as Iranmedex, Magiran, and SID were searched. All searches were restricted to English language between 1985 and 2017. A random effect meta-analysis is applied to estimate pooled effect size across initial studies. Funnel plot with Egger's test is used to assess potential publication bias.

RESULTS

Totally, five studies (478 samples) were included in meta-analysis. The meta-analyses of result showed that thyroid gland is affected by radiotherapy significantly and the TSH increased after radiotherapy (z = 2.68, P = 0.007). The pooled estimate of difference mean for TSH was 0.90 (95% CI 0.24, 1.55). In studies among patients with breast cancer RT, hypothyroidism was reported more than other thyroid disorders. There was not showed possibility publication bias among studies (P > 0.05).

CONCLUSION

This study demonstrated that thyroid gland is affected by radiotherapy significantly and the TSH increased after radiotherapy. Protecting thyroid gland during radiation and follow-up of patients with breast cancer RT are suggested for the assessment of thyroid gland dysfunction.

Radiotherapeutic factors affecting the incidence of developing hypothyroidism after radiotherapy for head and neck squamous cell cancer

PURPOSE

The purpose of this study is to determine radiotherapy (RT) dose-volumetric threshold of radiation-induced hypothyroidism (HT) in head and neck squamous cell carcinoma (HNSCC) patients.

PATIENTS AND METHODS

The diagnosis of HT in 78 HNSCC patients treated with RT was based on a thyroid stimulating hormone (TSH) level greater than the maximum value of laboratory range. In all patients, dose-volumetric parameters were analyzed according to their relation to development of HT, and thyroid volumes spared from doses ≥10, 20, 30, 40 and 50 Gy (V10, V20, V30, V40 and V50) were analyzed from the dose volume histograms (DVHs).

RESULTS

Median follow-up duration was 31 months. At the end of study, 33 patients (42.3%) developed HT and the cumulative incidence of HT was 24.6%, 36.5% and 42.3% at one, two and three years, respectively. V30 of 42.1% (P = 0.005) was defined as dose-volumetric threshold of radiation-induced HT in HNSCC patients. Our analysis showed that V30 separates patients into low- and high-risk groups; the incidence of radiation-induced HT in the group with V30 < 42.1% and V30 ≥ 42.1% was 29.4% and 71.4%, respectively (P = 0.002).

CONCLUSIONS

The V30 may predict risk of developing HT after RT for HNSCC patients. V30 of 42.1%, defined as dose-volumetric threshold of radiation-induced HT, can be useful in treatment planning of HNSCC patients.

Prevalence of hypothyroidism among patients with breast cancer treated with radiation to the supraclavicular field: a single-centre survey

Purpose

We investigated the prevalence of hypothyroidism (HT) in patients with breast cancer who received radiation therapy to the supraclavicular (SC) field to evaluate the effect of radiation on thyroid.

Methods

Between April 2007 and May 2016, consecutive patients with invasive breast cancer who received SC radiation were recruited. Thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured between April and August 2016. On the basis of the radiation-planning CT images, thyroid volume was calculated and dose–volume parameters were estimated. The endpoints were the prevalence of HT as determined by high levels of TSH and low levels of fT4 in serum, and the prevalence of subclinical HT, determined by high-serum TSH and normal fT4.

Results

Among the 68 consecutive patients, 26 were excluded from evaluation (10 patients died, 6 had a history of previous thyroid disease and 10 were lost to follow-up). One (2.4%) and six (14.3%) of these patients had HT and subclinical HT, respectively, with a mean TSH level of 8.27 µU/mL. By univariate analysis, a predictive factor of HT and subclinical HT was a thyroid volume <8 cm³ (OR 6.44, 95% CI 1.14 to 36.6; p=0.043). Multivariate analysis also showed an association between thyroid volume <8 cm³ and HT or subclinical HT (OR 18.48, 95% CI 1.48 to 230.86; p=0.024).

Conclusions

The prevalence of HT in patients with breast cancer studied was relatively low. Although thyroid volume appeared to be a predictive marker of HT in this cohort, further prospective evaluation is needed.

Thyroid Dysfunction and Autoimmune Thyroid Diseases Among Atomic Bomb Survivors Exposed in Childhood

CONTEXT

The risk of thyroid cancer increases and persists for decades among individuals exposed to ionizing radiation in childhood, although the long-term effects of childhood exposure to medium to low doses of radiation on thyroid dysfunction and autoimmune thyroid diseases have remained unclear.

OBJECTIVE

To evaluate radiation dose responses for the prevalence of thyroid dysfunction and autoimmune thyroid disease among atomic bomb survivors exposed in childhood.

DESIGN, SETTING, AND PARTICIPANTS

Hiroshima and Nagasaki atomic bomb survivors who were younger than 10 years old at exposure underwent thyroid examinations at the Radiation Effects Research Foundation between 2007 and 2011, which was 62 to 66 years after the bombing. Data from 2668 participants (mean age, 68.2 years; 1455 women) with known atomic bomb thyroid radiation doses (mean dose, 0.182 Gy; dose range, 0 to 4.040 Gy) were analyzed.

MAIN OUTCOME AND MEASURES

Dose-response relationships between atomic bomb radiation dose and the prevalence of hypothyroidism, hyperthyroidism (Graves' disease), and positive for antithyroid antibodies.

RESULTS

Prevalences were determined for hypothyroidism (129 cases, 7.8%), hyperthyroidism (32 cases of Graves' disease, 1.2%), and positive for antithyroid antibodies (573 cases, 21.5%). None of these was associated with thyroid radiation dose. Neither thyroid antibody-positive nor -negative hypothyroidism was associated with thyroid radiation dose. Additional analyses using alternative definitions of hypothyroidism and hyperthyroidism found that radiation dose responses were not significant.

CONCLUSIONS

Radiation effects on thyroid dysfunction and autoimmune thyroid diseases were not observed among atomic bomb survivors exposed in childhood, at 62 to 66 years earlier. The cross-sectional design and survival bias were limitations of this study.

Metabolic syndrome induced by anticancer treatment in childhood cancer survivors

The number of childhood cancer survivors is increasing as survival rates improve. However, complications after treatment have not received much attention, particularly metabolic syndrome. Metabolic syndrome comprises central obesity, dyslipidemia, hypertension, and insulin resistance, and cancer survivors have higher risks of cardiovascular events compared with the general population. The mechanism by which cancer treatment induces metabolic syndrome is unclear. However, its pathophysiology can be categorized based on the cancer treatment type administered. Brain surgery or radiotherapy may induce metabolic syndrome by damaging the hypothalamic-pituitary axis, which may induce pituitary hormone deficiencies. Local therapy administered to particular endocrine organs directly damages the organs and causes hormone deficiencies, which induce obesity and dyslipidemia leading to metabolic syndrome. Chemotherapeutic agents interfere with cell generation and growth, damage the vascular endothelial cells, and increase the cardiovascular risk. Moreover, chemotherapeutic agents induce oxidative stress, which also induces metabolic syndrome. Physical inactivity caused by cancer treatment or the cancer itself, dietary restrictions, and the frequent use of antibiotics may also be risk factors for metabolic syndrome. Since childhood cancer survivors with metabolic syndrome have higher risks of cardiovascular events at an earlier age, early interventions should be considered. The optimal timing of interventions and drug use has not been established, but lifestyle modifications and exercise interventions that begin during cancer treatment might be beneficial and tailored education and interventions that account for individual patients' circumstances are needed. This review evaluates the recent literature that describes metabolic syndrome in cancer survivors, with a focus on its pathophysiology.

Calculation of Thyroid Dose with Planner System and Evaluation of Thyroid Function after Radiotherapy for Patients with Breast Cancer

BACKGROUND

Much research has widely been conducted into thyroid hormones levels following radiotherapy for breast cancer. Consequently, in this study, we evaluated to relate the rate of thyroid hormones levels with the dose distribution among breast cancer patients.

MATERIAL AND METHODS

Thirty patients were treated with 4-field breast cancer radiotherapy. The dose volume histograms, the volume percentage of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual average thyroid dose over the whole gland derived from their computed tomography-based treatment plans. Then, in serum samples triiodothyronine [T3], thyroxine [T4], thyroid-stimulating hormone [TSH] of the patients were measured before and after radiotherapy.

RESULTS

There were no significant differences in thyroid hormones levels before and after radiotherapy for patients with breast cancer (P value >.05).

CONCLUSION

On the balance, we understood that thyroid stimulating hormones levels did not change before and after cancer breast radiotherapy.

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

BACKGROUND

Thyroid dysfunction is common after radiotherapy (RT) for patients with head and neck cancers. We attempted to discover RT dose parameters that correspond with RT-induced thyroid dysfunction.

METHODS

Records of 102 patients who received RT from 2008 to 2010 were reviewed with respect to thyroid function. Abnormalities were grouped in 2 ways: (1) none, transient, or permanent; and (2) overt or subclinical.

RESULTS

At median follow-up of 33.5 months, incidence of any thyroid abnormality was 39.2% (women vs men - 50% vs 35%). Permanent dysfunction was seen in 24.5% with higher incidence in women versus men (42.9% vs 17.6%; p = .0081). Permanent abnormalities most strongly correlated with D_50% (p = .0275). V_50Gy also correlated with thyroid dysfunction post-RT (p = .0316). Concurrent chemotherapy increased permanent dysfunction (p = .0008).

CONCLUSION

Achieving D_50% <50 Gy, V₅₀ <50%, and mean dose <54.58 Gy during RT planning may decrease the incidence; whereas female sex and concurrent chemotherapy seem to increase the risk of RT-induced hypothyroidism. © 2016 Wiley Periodicals, Inc. Head Neck 39: 548-554, 2017.

Calculation of Thyroid Dose with Planner System and Evaluation of Thyroid Function after Radiotherapy for Patients with Breast Cancer

BACKGROUND

Much research has widely been conducted into thyroid hormones levels following radiotherapy for breast cancer. Consequently, in this study, we evaluated to relate the rate of thyroid hormones levels with the dose distribution among breast cancer patients.

MATERIAL AND METHODS

Thirty patients were treated with 4-field breast cancer radiotherapy. The dose volume histograms, the volume percentage of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual average thyroid dose over the whole gland derived from their computed tomography-based treatment plans. Then, in serum samples triiodothyronine [T3], thyroxine [T4], thyroid-stimulating hormone [TSH] of the patients were measured before and after radiotherapy.

RESULTS

There were no significant differences in thyroid hormones levels before and after radiotherapy for patients with breast cancer (P value >.05).

CONCLUSION

On the balance, we understood that thyroid stimulating hormones levels did not change before and after cancer breast radiotherapy.

The survival rate and larynx preservation in elderly cancer patients who received surgical operation: A retrospective cohort study

BACKGROUND

To investigate the efficiency of surgical operation for patients over 70 years with hypopharyngeal cancer.

MATERIALS AND METHODS

A retrospective analysis of the medical records from 68 patients over 70 years-old with hypopharyngeal cancer who underwent different therapeutic regimen between 2000 and 2009 was conducted. 36 of 68 patients underwent larynx preservation. All patients were treated with surgical operation and adjuvant radiotherapy. A Kaplan-Meier method was employed to calculate the survival rate.

RESULTS

Overall 3 year-and 5 year-survival rates were 48.6% and 29.4% respectively. For patients who underwent larynx preservation, 5 year-survival rate was 30.5%, which was decreased compared to 3 year-survival rate (46.9%) However, 3 year- and 5 year-survival rates in patients without larynx preservation were 46.9% and 28.1% respectively, suggesting that no statistically significant difference of survival rates was found between patients with or without larynx preservation (P > 0.05). A majority of patients who receive larynx preservation exhibited normal breathing and eating abilities and could present an intelligible speech. 16 of 36 patients who preserved larynx and 14 of 32 patients who underwent laryngectomy showed postoperative complication. No significant difference was observed in these two treatments, indicating larynx preservation is not a factor for inducing complication.

CONCLUSION

This study provides evidence that the quality of life for elderly patients with hypopharyngeal cancer can be improved by optimizing the therapeutic regimen based on the physical condition of each patient.

American Cancer Society Head and Neck Cancer Survivorship Care Guideline

Answer questions and earn CME/CNE The American Cancer Society Head and Neck Cancer Survivorship Care Guideline was developed to assist primary care clinicians and other health practitioners with the care of head and neck cancer survivors, including monitoring for recurrence, screening for second primary cancers, assessment and management of long-term and late effects, health promotion, and care coordination. A systematic review of the literature was conducted using PubMed through April 2015, and a multidisciplinary expert workgroup with expertise in primary care, dentistry, surgical oncology, medical oncology, radiation oncology, clinical psychology, speech-language pathology, physical medicine and rehabilitation, the patient perspective, and nursing was assembled. While the guideline is based on a systematic review of the current literature, most evidence is not sufficient to warrant a strong recommendation. Therefore, recommendations should be viewed as consensus-based management strategies for assisting patients with physical and psychosocial effects of head and neck cancer and its treatment. CA Cancer J Clin 2016;66:203-239. © 2016 American Cancer Society.

Hypothyroidism in patients treated with radiotherapy for head and neck carcinoma: standardised long-term follow-up study

OBJECTIVE

Hypothyroidism is a common complication when radiotherapy is part of the treatment for head and neck tumours. This study aimed to show the incidence of hypothyroidism and possible risk factors in these patients.

METHODS

Factors related to the population, tumour, treatment and occurrence of hypothyroidism were analysed in 241 patients diagnosed with head and neck carcinoma.

RESULTS

Approximately 53 per cent of patients were diagnosed with radiation-induced hypothyroidism. Its occurrence was related to: tumour location, laryngeal surgery type, neck dissection type, post-operative complications, cervical radiotherapy and radiotherapy unit type (linear particle accelerator or telecobalt therapy technology).

CONCLUSION

Control of thyroid function should be standardised for several years after treatment, particularly in patients with risk factors, such as those treated with telecobalt therapy, those with post-operative complications and for whom the thyroid parenchyma is included in the irradiated area (laryngeal or pharyngeal location and bilateral cervical radiation).

[Clinical and paraclinical follow-up after radiotherapy for head and neck cancer]

Head and neck cancer management often involves heavy multimodal treatments including radiotherapy. Despite the improvement of intensity-modulated radiation therapy, acute and late toxicities remain important. After such treatment, patients have to face different potential problems, depending on the post-therapeutic delay. In this way, short-term follow-up permits to appreciate the healing of acute toxicities and response to treatment. Long-term follow-up aims to recognize second primitive tumours and distant failure, and to detect and manage late toxicities. Medical and psychosocial supportive cares are essential, even after several years of complete remission. The objective of this article is to review the modalities of short-term and long-term follow-up of patients who receive a radiotherapy for head and neck cancer.

The threshold of hypothyroidism after radiation therapy for head and neck cancer: a retrospective analysis of 116 cases

The purpose of the present study was to determine the risk factors for developing thyroid disorders based on a dose-volume histograms (DVHs) analysis. Data from a total of 116 consecutive patients undergoing 3D conformal radiation therapy for head and neck cancers was retrospectively evaluated. Radiation therapy was performed between April 2007 and December 2010. There were 108 males and 8 females included in the study. The median follow-up term was 24 months (range, 1-62 months). The thyroid function was evaluated by measuring thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels. The mean thyroid dose, and the volume of thyroid gland spared from doses ≥10, 20, 30 and 40 Gy (VS10, VS20, VS30 and VS40) were calculated for all patients. The thyroid dose and volume were calculated by the radiotherapy planning system (RTPS). The cumulative incidences of hypothyroidism were 21.1% and 36.4% at one year and two years, respectively, after the end of radiation therapy. In the DVH analyses, the patients who received a mean thyroid dose <30 Gy had a significantly lower incidence of hypothyroidism. The univariate analyses showed that the VS10, VS20, VS30 and VS40 were associated with the risk of hypothyroidism. Hypothyroidism was a relatively common type of late radiation-induced toxicity. A mean thyroid dose of 30 Gy may be a useful threshold for predicting the development of hypothyroidism after radiation therapy for head and neck cancers.

Improving target dose coverage and organ-at-risk sparing in intensity-modulated radiotherapy of advanced laryngeal cancer by a simple optimization technique

OBJECTIVE

To evaluate a simple optimization technique intended to improve planning target volume (PTV) dose coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) of advanced laryngeal cancer.

METHODS

Generally acceptable initial IMRT plans were generated for 12 patients and were improved individually by the following two techniques: (1) base dose function-based (BDF) technique, in which the treatment plans were reoptimized based on the initial IMRT plans; (2) dose-controlling structure-based (DCS) technique, in which the initial IMRT plans were reoptimized by adding constraints for hot and cold spots. The initial, BDF and DCS IMRT plans and additionally generated volumetric modulated arc therapy (VMAT) plans were compared concerning homogeneity index (HI) and conformity index (CI) of PTVs prescribed at 70 Gy/60 Gy (PTV70/PTV60), OAR sparing, monitor units (MUs) per fraction and total planning time.

RESULTS

Compared with the initial IMRT and DCS IMRT plans, the BDF technique provided superior HI/CI, by approximately 19-37%/4-11%, and lower doses to most OARs, by approximately 1-7%, except for the comparable HI of PTV60 to DCS IMRT plans. Compared with VMAT plans, the BDF technique provided comparable HI, CI and most-OAR sparing, except for the superior HI of PTV70, by approximately 13%. The BDF technique produced more MUs and reduced the planning time.

CONCLUSION

The BDF optimization technique for IMRT of advanced laryngeal cancer can improve target dose homogeneity and conformity, spare most OARs and is efficient.

ADVANCES IN KNOWLEDGE

A novel optimization technique for improving IMRT was assessed and found to be effective and efficient.

Volumetric modulated arc radiotherapy sparing the thyroid gland for early-stage glottic cancer: A dosimetrical analysis

Previous studies on advanced radiotherapy (RT) techniques for early stage glottic cancer have focused on sparing the carotid artery. However, the aim of the present study was to evaluate the dosimetric advantages of volumetric modulated arc therapy (VMAT) in terms of sparing the thyroid gland in early-stage glottic cancer patients. In total, 15 cT1N0M0 glottic cancer patients treated with definitive RT using VMAT were selected, and for dosimetric comparison, a conventional RT plan comprising opposed-lateral wedged fields was generated for each patient. The carotid artery, thyroid gland and spinal cord were considered organs at risk. The prescription dose was 63 Gy at 2.25 Gy per fraction. For the thyroid gland and carotid artery, all compared parameters were significantly lower with VMAT compared with conventional RT. For the thyroid gland, the median reduction rates of the mean dose (D_mean), the volume receiving ≥30% of the prescription dose (V₃₀) and the V₅₀ were 32.6, 40.9 and 46.0%, respectively. The D_mean was 14.7±2.6 Gy when using VMAT compared with 22.2±3.9 Gy when using conventional RT. The differences between the techniques in terms of planning target volume coverage and dose homogeneity were not significant. When considering a recent normal tissue complication probability model, which indicated the mean thyroid gland dose as the most significant predictor of radiation-induced hypothyroidism, the dosimetric advantage shown in this study may be valuable in reducing hypothyroidism following RT for early stage glottic cancer patients.

The relationship between thyroid dose and diagnosis of primary hypothyroidism in pediatric brain tumor patients receiving craniospinal irradiation

PURPOSE

The aim of this work is to determine if a relationship exists between thyroid dose and incidence of primary hypothyroidism (PH) in children undergoing craniospinal irradiation (CSI).

METHODS

A total of 22 patients received CSI with evaluable thyroid dose information. All patients received concurrent chemotherapy and 21 patients (95%) received adjuvant chemotherapy. Median follow-up was 42.9 months.

RESULTS

The incidence of PH in our cohort was 59% at a median time after radiotherapy of 3.5 years (range: 8 months to 7.5 years). Mean thyroid dose appeared to best predict for PH, with a median of 2080 cGy for patients with PH versus 1736 cGy for children without PH (p=0.057). There was no association between the rate of PH and sex, age, CSI dose, minimum thyroid dose and maximum thyroid dose.

CONCLUSIONS

A relationship may exist between the mean thyroid dose and incidence of PH in patients undergoing CSI. Thus, new strategies to protect the thyroid gland may be warranted.

Dose-volumetric parameters for predicting hypothyroidism after radiotherapy for head and neck cancer

OBJECTIVE

To investigate predictors affecting the development of hypothyroidism after radiotherapy for head and neck cancer, focusing on radiation dose-volumetric parameters, and to determine the appropriate radiation dose-volumetric threshold of radiation-induced hypothyroidism.

METHODS

A total of 114 patients with head and neck cancer whose radiotherapy fields included the thyroid gland were analysed. The purpose of the radiotherapy was either definitive (n = 81) or post-operative (n = 33). Thyroid function was monitored before starting radiotherapy and after completion of radiotherapy at 1 month, 6 months, 1 year and 2 years. A diagnosis of hypothyroidism was based on a thyroid stimulating hormone value greater than the maximum value of laboratory range, regardless of symptoms. In all patients, dose volumetric parameters were analysed.

RESULTS

Median follow-up duration was 25 months (range; 6-38). Forty-six percent of the patients were diagnosed as hypothyroidism after a median time of 8 months (range; 1-24). There were no significant differences in the distribution of age, gender, surgery, radiotherapy technique and chemotherapy between the euthyroid group and the hypothyroid group. In univariate analysis, the mean dose and V35-V50 results were significantly associated with hypothyroidism. The V45 is the only variable that independently contributes to the prediction of hypothyroidism in multivariate analysis and V45 of 50% was a threshold value. If V45 was <50%, the cumulative incidence of hypothyroidism at 1 year was 22.8%, whereas the incidence was 56.1% if V45 was ≥50% (P = 0.034).

CONCLUSIONS

The V45 may predict risk of developing hypothyroidism after radiotherapy for head and neck cancer, and a V45 of 50% can be a useful dose-volumetric threshold of radiation-induced hypothyroidism.