A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model

Boomsma, Marjolein J.; Bijl, H.P.; Christianen, Miranda E.M.C.; Beetz, Ivo; Chouvalova, O.; Steenbakkers, Roel J.H.M.; Laan, Bernard F. A. M. van der; Wolffenbuttel, Bruce H. R.; Oosting, Sjoukje F.; Schilstra, Cornelis; Langendijk, Johannes A.

doi:10.1016/j.ijrobp.2012.05.020

Cited by 93 publications

(149 citation statements)

References 15 publications

Supporting

Mentioning

132

Contrasting

Unclassified

Order By: Relevance

“…Previous studies found that gender, 8,9 age, 10 neck surgery 11 and thyroid volume [12][13][14] were risk factors for RHT. In addition, a high radiation dose and large thyroid volume in the treatment field are related to RHT.…”

Section: Introductionmentioning

confidence: 95%

“…10,15 Threedimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) enable the analysis of dose-volume factors. The minimum dose (D min ) and mean dose (D mean ), the percentage of thyroid volume receiving .30, 45 or 50 Gy, the absolute thyroid volume spared from 45 Gy or less and volume spared from 60 Gy or less 13,14,[16][17][18][19][20][21][22][23][24] were found to be dosimetric predictors for RHT. However, predictors and dose constraints varied according to the study.…”

Section: Introductionmentioning

confidence: 98%

“…However, predictors and dose constraints varied according to the study. 13,14,[16][17][18][19][20][21][22][23][24][25] Nasopharyngeal carcinoma (NPC) is a prevalent cancer in southern China. Irradiation to the bilateral neck is a regular practice because of a high incidence 26 of neck node involvement.…”

Section: Introductionmentioning

confidence: 99%

“…13,14,18,28 However, NTCP model is not convenient in clinical practice. A nomogram is widely used for cancer prognosis and reduces statistical predictive models into a graphical format.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Nomogram for radiation-induced hypothyroidism prediction in nasopharyngeal carcinoma after treatment

Luo

et al. 2017

The British Journal of Radiology

View full text Add to dashboard Cite

The authors Ren Luo and Mei Li contributed equally to this work.Objective: The aim of this study was to develop a nomogram for radiation-induced hypothyroidism (RHT) prediction. Methods: We collected data from 164 patients with nasopharyngeal carcinoma (NPC) in our previous prospective study. Biochemical hypothyroidism was defined as a serum thyroid-stimulating hormone level greater than the normal value. We collected both clinical and dose-volume factors. A univariate Cox regression analysis was performed to identify RHT risk factors. Optimal predictors were selected according to the least absolute shrinkage and selection operator (LASSO). We then selected the Cox regression models that best balanced the prediction performance and practicability to build a nomogram for RHT prediction. Results: There were 38 (23.2%) patients who developed RHT, and the median follow-up was 24 months. The univariate Cox regression analysis indicated that gender, minimum dose, mean dose (D mean ) and V 25 -V 60 [V x (%), the percentage of thyroid volume receiving .x Gy] of the thyroid were significantly associated with RHT. The variables of gender, receiving chemotherapy or not (chemo), D mean and V 50 were selected using the LASSO analysis. A nomogram based on a three-variable (gender, chemo and V 50 ) Cox regression model was constructed, and its concordance index was 0.72. Good accordance between prediction and observation was showed by calibration curves in the probability of RHT at 18, 24 and 30 months. Conclusion: This study built a nomogram for RHT in NPC survivors by analyzing both clinical and dose-volume parameters using LASSO. Thus, the individual dose constraint could be achieved in a visual format. Advances in knowledge: This study used LASSO to more accurately address the multicollinear problem between variables. The resulting nomogram will help physicians predict RHT. INTRODUCTIONRadiation-induced hypothyroidism (RHT) is a common late complication after irradiation to the neck area. The majority of early RHT cases are silent because subclinical hypothyroidism (HT) can be detected only by thyroid hormone tests [elevated serum thyroid-stimulating hormone (TSH) and normal serum free thyroxine (fT4) and/ or serum free triiodothyronine (fT3)]. However, other cases show overt disease [overt hypothyroidism (overt HT)] that presents with elevated TSH and decreased fT4 and/or fT3. The incidence of subclinical HT is 24-50%, and overt HT develops in 6-20% of patients with head and neck cancer who receive radiotherapy (RT).1 HT has been demonstrated to be correlated with the development of cardiovascular and pulmonary disorders in addition to diabetes mellitus, 2-7 which increases the adverse effects of RHT on patient quality of life.

show abstract

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

“…13,14,18,28 However, NTCP model is not convenient in clinical practice. A nomogram is widely used for cancer prognosis and reduces statistical predictive models into a graphical format.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nomogram for radiation-induced hypothyroidism prediction in nasopharyngeal carcinoma after treatment

Luo

et al. 2017

The British Journal of Radiology

View full text Add to dashboard Cite

show abstract

“…1 and 2, and Table I). The normal tissue complication probability model of radiation-induced hypothyroidism indicated that the probability of hypothyroidism increases with a higher mean dose to the thyroid gland (odds ratio, 1.064/Gy) (23). In a previous study, VMAT exhibited a median 8 Gy reduction in mean thyroid dose compared with conventional RT (17).…”

mentioning

confidence: 93%

Volumetric modulated arc radiotherapy of the whole larynx, followed by a single affected vocal cord, for T1a glottic cancer: Dosimetric analysis of a case

Yeo

2016

Molecular and Clinical Oncology

View full text Add to dashboard Cite

Abstract. Radiation therapy (RT) and endolaryngeal surgery are standard treatments for early-stage glottic cancer. They have closely matched oncological outcomes; however, it is debatable which method is superior in terms of functional outcomes. Several dosimetric studies have demonstrated that, compared with conventional RT, intensity-modulated RT (IMRT) reduces unnecessary radiation of the adjacent normal tissues, including the carotid artery and thyroid gland. However, RT targets the whole larynx, whereas endolaryngeal surgery is a highly focused treatment involving the en bloc resection of a tumor with safety margins. For T1a glottic cancer, in which the tumor is limited to one vocal cord, the technical feasibility of targeting IMRT on the single vocal cord affected has been investigated; however, the clinical feasibility and the possibility of inferior local control remain to be elucidated. In the present case study, IMRT was used to treat the whole larynx first, and then to treat a single vocal cord. The patient in the present study had T1a glottic cancer, and received volumetric modulated arc therapy with a total dose of 63 Gy/28 fractions. The first treatment phase (40.5 Gy/18 fractions) targeted the whole larynx to eliminate subclinical disease. The second treatment phase (22.5 Gy/10 fractions) targeted only the involved vocal cord. During this treatment phase, the exposure of the non-involved right vocal cord, the right carotid artery and the thyroid gland to the radiation was lower compared with the continuation of the initial treatment approach. These findings suggested that changing the target volume from the whole larynx to the affected vocal cord during the course of IMRT is feasible for T1a glottic cancer, and that it may reduce functional side effects while maintaining oncological outcomes.

show abstract

Thyroid dose‐volume thresholds for the risk of radiation‐related hypothyroidism in nasopharyngeal carcinoma treated with intensity‐modulated radiotherapy—A single‐institution study

Huang

Tan²,

Guo

et al. 2019

Cancer Medicine

View full text Add to dashboard Cite

BackgroundTo identify thyroid dose‐volume thresholds for radiotherapy (RT)‐related hypothyroidism (HT) in patients with nasopharyngeal carcinoma (NPC) treated with intensity‐modulated RT (IMRT). In this way, we desired to guide the design of treatment plans and, finally, lower HT prevalence.MethodsIn total, 345 NPC patients treated with IMRT were evaluated retrospectively during a median follow‐up of 45.2 (range, 11.3‐64.9) months. Serum‐based assessments of thyroid function before and after IMRT were monitored periodically. Thyroid dose‐volume parameters were analyzed for their association with HT risk.ResultsIn total, 44.1% of patients (152/345) developed primary HT. Analyses of thyroid dose‐volume parameters identified a stringent dose‐volume histogram (DVH) threshold defined by V 25Gy (the percentage thyroid volume that receives >25 Gy, not the absolute volume) ≤60%, V 35Gy ≤ 55%, and V 45Gy ≤ 45%. Patients whose thyroid DVHs satisfied these constraints had a lower prevalence of 2‐year HT compared with the overall prevalence (13.2% vs 25.8%, P < .001). Another DVH was defined by V 25Gy > 95%, V 35Gy > 90%, and V 45Gy > 75%, and patients whose thyroid DVHs satisfied with these constraints had a higher prevalence of 2‐year HT than the overall incidence (36.0% vs 25.8%, P < .001).ConclusionWe recommend V 25Gy ≤ 60%, V 35Gy ≤ 55%, and V 45Gy ≤ 45% as the “stringent” DVH line, and V 25Gy > 95%, V 35Gy > 90%, and V 45Gy > 75% as the “inhibition” DVH line, under the precondition of not compromising the target coverage. These findings could help in the design of individual treatment plans and, eventually, to lowering of HT prevalence.

show abstract

A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model

Cited by 93 publications

References 15 publications

Nomogram for radiation-induced hypothyroidism prediction in nasopharyngeal carcinoma after treatment

Nomogram for radiation-induced hypothyroidism prediction in nasopharyngeal carcinoma after treatment

Volumetric modulated arc radiotherapy of the whole larynx, followed by a single affected vocal cord, for T1a glottic cancer: Dosimetric analysis of a case

Thyroid dose‐volume thresholds for the risk of radiation‐related hypothyroidism in nasopharyngeal carcinoma treated with intensity‐modulated radiotherapy—A single‐institution study

Contact Info

Product

Resources

About