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Conference Paper: Dosimetric predictors of Hypothyroidism after Radical Intensity Modulated Radiation Therapy for Nasopharyngeal Carcinoma

TitleDosimetric predictors of Hypothyroidism after Radical Intensity Modulated Radiation Therapy for Nasopharyngeal Carcinoma
Authors
Issue Date2016
PublisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/ijrobp
Citation
The 2016 Multidisciplinary Head and Neck Cancer Symposium, Scottsdale, AZ., 18-20 February 2016. In International Journal of Radiation Oncology - Biology - Physics, 2016, v. 94 n. 4, p. 912, abstract no. 204 How to Cite?
AbstractPURPOSE/OBJECTIVE(S): We investigated for dosimetric predictors of hypothyroidism after radical intensity modulated radiation therapy (IMRT) for nonmetastatic nasopharyngeal carcinoma (NPC). MATERIALS/METHODS: Patients with nonmetastatic NPC treated with radical IMRT from 2008 to 2013 were reviewed. They were regularly monitored clinically with serum thyroid function tests before and after IMRT. Univariable and multivariable analyses were performed for demographic and dosimetric predictors of biochemical and clinical hypothyroidism. RESULTS: A total of 149 patients fulfilled eligibility criteria. After a median follow-up duration of 3.1 years (range, 1.3-8.2 years), 33 patients (22.1%) and 21 patients (14.1%) developed biochemical and clinical hypothyroidism, respectively. Eight patients (24.2%) who had biochemical hypothyroidism developed clinical hypothyroidism later. Univariable and multivariable analyses revealed that volume of the thyroid (P=.002, multivariable), VS60 (the absolute thyroid volume spared from 60 Gy or less) (P<.001, multivariable), and VS45 (P<.001, multivariable) of the thyroid were significant predictive factors of biochemical hypothyroidism. The freedom from biochemical hypothyroidism was longer for those whose VS60≥10 mL (mean 90.9 months vs 62.6 months; P<.001) and VS45≥5 mL (mean 91.9 months vs 65.2 months; P=.001). Similarly, multivariable analyses revealed that VS60 (P=.001) and VS45 (P=.003) were significant predictors of clinical hypothyroidism. The freedom from clinical hypothyroidism was longer for those whose VS60≥10 mL (91.5 months vs 73.3 months, P=.002) and VS45≥5 mL (91.5 months vs 75.9 months, P=.007). Receiver-operating characteristics (ROC) analyses revealed that the area-under-the-curve (AUC) value for VS60 was significantly higher than that for VS45 for both biochemical (0.751 vs 0.660; P=.009) and clinical hypothyroidism (0.718 vs 0.607; P=.007), respectively. CONCLUSION: VS60 and VS45 of the thyroid significantly predicted post-IMRT hypothyroidism and should be considered important priorities of dose constraints during IMRT optimisation for NPC.
DescriptionPosters
pp. 862-973 of this journal issue entitled: 2016 Multidisciplinary Head and Neck Cancer Symposium Meeting Abstracts
Persistent Identifierhttp://hdl.handle.net/10722/241011
ISSN
2015 Impact Factor: 4.495
2015 SCImago Journal Rankings: 2.274

 

DC FieldValueLanguage
dc.contributor.authorLee, VHF-
dc.contributor.authorChan, ASW-
dc.contributor.authorChoi, CW-
dc.contributor.authorKwong, DLW-
dc.contributor.authorLam, KO-
dc.contributor.authorTong, CC-
dc.contributor.authorSze, CKH-
dc.contributor.authorNg, SC-
dc.contributor.authorLeung, TW-
dc.date.accessioned2017-05-22T09:21:04Z-
dc.date.available2017-05-22T09:21:04Z-
dc.date.issued2016-
dc.identifier.citationThe 2016 Multidisciplinary Head and Neck Cancer Symposium, Scottsdale, AZ., 18-20 February 2016. In International Journal of Radiation Oncology - Biology - Physics, 2016, v. 94 n. 4, p. 912, abstract no. 204-
dc.identifier.issn0360-3016-
dc.identifier.urihttp://hdl.handle.net/10722/241011-
dc.descriptionPosters-
dc.descriptionpp. 862-973 of this journal issue entitled: 2016 Multidisciplinary Head and Neck Cancer Symposium Meeting Abstracts-
dc.description.abstractPURPOSE/OBJECTIVE(S): We investigated for dosimetric predictors of hypothyroidism after radical intensity modulated radiation therapy (IMRT) for nonmetastatic nasopharyngeal carcinoma (NPC). MATERIALS/METHODS: Patients with nonmetastatic NPC treated with radical IMRT from 2008 to 2013 were reviewed. They were regularly monitored clinically with serum thyroid function tests before and after IMRT. Univariable and multivariable analyses were performed for demographic and dosimetric predictors of biochemical and clinical hypothyroidism. RESULTS: A total of 149 patients fulfilled eligibility criteria. After a median follow-up duration of 3.1 years (range, 1.3-8.2 years), 33 patients (22.1%) and 21 patients (14.1%) developed biochemical and clinical hypothyroidism, respectively. Eight patients (24.2%) who had biochemical hypothyroidism developed clinical hypothyroidism later. Univariable and multivariable analyses revealed that volume of the thyroid (P=.002, multivariable), VS60 (the absolute thyroid volume spared from 60 Gy or less) (P<.001, multivariable), and VS45 (P<.001, multivariable) of the thyroid were significant predictive factors of biochemical hypothyroidism. The freedom from biochemical hypothyroidism was longer for those whose VS60≥10 mL (mean 90.9 months vs 62.6 months; P<.001) and VS45≥5 mL (mean 91.9 months vs 65.2 months; P=.001). Similarly, multivariable analyses revealed that VS60 (P=.001) and VS45 (P=.003) were significant predictors of clinical hypothyroidism. The freedom from clinical hypothyroidism was longer for those whose VS60≥10 mL (91.5 months vs 73.3 months, P=.002) and VS45≥5 mL (91.5 months vs 75.9 months, P=.007). Receiver-operating characteristics (ROC) analyses revealed that the area-under-the-curve (AUC) value for VS60 was significantly higher than that for VS45 for both biochemical (0.751 vs 0.660; P=.009) and clinical hypothyroidism (0.718 vs 0.607; P=.007), respectively. CONCLUSION: VS60 and VS45 of the thyroid significantly predicted post-IMRT hypothyroidism and should be considered important priorities of dose constraints during IMRT optimisation for NPC.-
dc.languageeng-
dc.publisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/ijrobp-
dc.relation.ispartofInternational Journal of Radiation Oncology - Biology - Physics-
dc.rightsPosting accepted manuscript (postprint): © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/-
dc.titleDosimetric predictors of Hypothyroidism after Radical Intensity Modulated Radiation Therapy for Nasopharyngeal Carcinoma-
dc.typeConference_Paper-
dc.identifier.emailLee, VHF: vhflee@hku.hk-
dc.identifier.emailChan, ASW: chansw3@hku.hk-
dc.identifier.emailChoi, CW: hcchoi@hku.hk-
dc.identifier.emailKwong, DLW: dlwkwong@hku.hk-
dc.identifier.emailLam, KO: lamkaon@hku.hk-
dc.identifier.emailTong, CC: tccz01@hku.hk-
dc.identifier.emailSze, CKH: henrysze@graduate.hku.hk-
dc.identifier.emailLeung, TW: ltw920@hkucc.hku.hk-
dc.identifier.authorityLee, VHF=rp00264-
dc.identifier.authorityChan, ASW=rp00288-
dc.identifier.authorityKwong, DLW=rp00414-
dc.identifier.authorityLam, KO=rp01501-
dc.identifier.authoritySze, CKH=rp01697-
dc.description.naturelink_to_OA_fulltext-
dc.identifier.doi10.1016/j.ijrobp.2015.12.141-
dc.identifier.hkuros272224-
dc.identifier.volume94-
dc.identifier.issue4-
dc.identifier.spage912, abstract no. 204-
dc.identifier.epage912, abstract no. 204-
dc.publisher.placeUnited States-

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