Effect of dose constraint on the thyroid gland during locoregional intensity‐modulated radiotherapy in breast cancer patients

Haciislamoglu, Emel; Canyılmaz, Emine; Gedik, Sonay; Aynacı, Osman; Serdar, Lasif; Yöney, Adnan

doi:10.1002/acm2.12668

Cited by 8 publications

(10 citation statements)

References 35 publications

(63 reference statements)

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“…Gender (10)(11)(12), age (5,13,14), and thyroid volume (10,15) are factors that affect hypothyroidism after radiotherapy, but thyroid exposure dose is the most important factor (11,16). The incidence of hypothyroidism increases with the exposure dose, and its specific threshold is still inconclusive.…”

Section: Introductionmentioning

confidence: 99%

Multivariate NTCP Model of Hypothyroidism After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

Shen

Peng

et al. 2021

Front. Oncol.

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ObjectiveTo evaluate the incidence of hypothyroidism in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT), analyze its correlation with multiple influencing factors such as thyroid exposure dose, thyroid volume, and gender, and construct a multivariate-based normal tissue complication probability (NTCP) model for the occurrence of hypothyroidism after IMRT.Materials and MethodsThe thyroid hormone levels of patients at different points in time before and after radiotherapy were tested, and statistics on the incidence of hypothyroidism after treatment were obtained. The dose-volume data of patients’ thyroids were converted into EQD2 equivalent dose values. The correlation between hypothyroidism after radiotherapy and thyroid exposure dose, thyroid volume, gender, and other factors was analyzed, and an NTCP model was constructed.ResultsA total of 69 patients with nasopharyngeal carcinoma were enrolled in this study. Twelve months after radiotherapy, a total of 24 patients (34.8%) developed hypothyroidism. Univariate analysis and multivariate analysis revealed that the average thyroid dose and thyroid volume are the most important factors affecting hypothyroidism after radiotherapy. The NTCP model constructed based on the average dose and thyroid volume has a good degree of fit.ConclusionThe volume and average dose of the thyroid gland are the key factors affecting the occurrence of hypothyroidism in patients with nasopharyngeal carcinoma after radiotherapy. The NTCP model constructed based on multivariate construction suggests that reducing the average dose of the thyroid to the greatest extent is an effective way to protect thyroid functions.

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Section: Introductionmentioning

confidence: 99%

Multivariate NTCP Model of Hypothyroidism After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

Shen

Peng

et al. 2021

Front. Oncol.

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“…Si raccomanda comunque il riconoscimento della tiroide come organo a rischio (OAR) per ridurre al minimo la dose di radiazioni e l'esposizione al volume tiroideo 178 .…”

Section: (E) Ipotiroidismounclassified

AIRO Breast Cancer Group Best Clinical Practice 2022 Update

Ciabattoni

Gregucci

Rose

et al. 2022

Tumori

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Introduction: Breast cancer is the most common tumor in women and represents the leading cause of cancer death. Radiation therapy plays a key-role in the treatment of all breast cancer stages. Therefore, the adoption of evidence-based treatments is warranted, to ensure equity of access and standardization of care in clinical practice. Method: This national document on the highest evidence-based available data was developed and endorsed by the Italian Association of Radiation and Clinical Oncology (AIRO) Breast Cancer Group. We analyzed literature data regarding breast radiation therapy, using the SIGN (Scottish Intercollegiate Guidelines Network) methodology ( www.sign.ac.uk ). Updated findings from the literature were examined, including the highest levels of evidence (meta-analyses, randomized trials, and international guidelines) with a significant impact on clinical practice. The document deals with the role of radiation therapy in the treatment of primary breast cancer, local relapse, and metastatic disease, with focus on diagnosis, staging, local and systemic therapies, and follow up. Information is given on indications, techniques, total doses, and fractionations. Results: An extensive literature review from 2013 to 2021 was performed. The work was organized according to a general index of different topics and most chapters included individual questions and, when possible, synoptic and summary tables. Indications for radiation therapy in breast cancer were examined and integrated with other oncological treatments. A total of 50 questions were analyzed and answered. Four large areas of interest were investigated: (1) general strategy (multidisciplinary approach, contraindications, preliminary assessments, staging and management of patients with electronic devices); (2) systemic therapy (primary, adjuvant, in metastatic setting); (3) clinical aspects (invasive, non-invasive and micro-invasive carcinoma; particular situations such as young and elderly patients, breast cancer in males and cancer during pregnancy; follow up with possible acute and late toxicities; loco-regional relapse and metastatic disease); (4) technical aspects (radiation after conservative surgery or mastectomy, indications for boost, lymph node radiotherapy and partial breast irradiation). Appendixes about tumor bed boost and breast and lymph nodes contouring were implemented, including a dedicated web application. The scientific work was reviewed and validated by an expert group of breast cancer key-opinion leaders. Conclusions: Optimal breast cancer management requires a multidisciplinary approach sharing therapeutic strategies with the other involved specialists and the patient, within a coordinated and dedicated clinical path. In recent years, the high-level quality radiation therapy has shown a significant impact on local control and survival of breast cancer patients. Therefore, it is necessary to offer and guarantee accurate treatments according to the best standards of evidence-based medicine.

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“…Thus, consensus was reached that delineation of the contralateral breast should be performed in those individual patients < 40 years in which this dose level might be reached. For the thyroid, it was concluded that V30Gy should be evaluated when lymph node levels 3 and 4 are part of the target volume [20].…”

Section: Consensus For Organs At Riskmentioning

confidence: 99%

Harmonization of breast cancer radiotherapy treatment planning in the Netherlands

Hurkmans

Duisters

Peters-Verhoeven

et al. 2021

Technical Innovations & Patient Support in Radiation Oncolo

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The aim was to reach consensus in The Netherlands on which parameters should be used to evaluate breast cancer radiotherapy (RT) plans. Materials and methods: A Benchmark Case with delineated planning target volumes (PTVs) and Organs At Risk (OARs) was sent to all Dutch radiotherapy centres in combination with a questionnaire, with the request to generate RT plans prescribing 15 times 2.67 Gy for four different treatment indications according to the institutional irradiation technique. The plans and accompanying questionnaire answers were analysed using descriptive statistics. These results, together with a harmonisation proposal, were sent to all centres. The proposal was discussed at a meeting of the Dutch Society of Radiation Oncology breast cancer platform. Distinct parameters were accepted if consensus on them was reached. Results: 19 out of 20 Dutch departments participated in this study. PTV coverage varied considerably, with D98% between 63% and 99% for the breast and between 37% and 97% for the internal mammary nodes (IMN). Also substantial OAR dose differences were observed, with e.g. mean heart doses ranging between 1.85 Gy and 5.42 Gy in case the IMN were included in the PTV. For evaluation of the PTVs D98%, D2% and Dmean were chosen to report on, with target values of ≥ 95% (90% for the PTV_IMN), ≤ 107%, and 99-101%, respectively. For OARs, consensus was reached on the parameters to be evaluated, without target values: Dmean of the heart, Dmean and V5% of the lungs, and in case of periclavicular radiotherapy V30Gy of the thyroid gland. For patients younger than 40 years a contralateral mean breast dose of ≤ 1 Gy was agreed upon. Conclusion:A new Dutch consensus guideline for evaluation of breast cancer RT plans has been established.

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Effect of dose constraint on the thyroid gland during locoregional intensity‐modulated radiotherapy in breast cancer patients

Cited by 8 publications

References 35 publications

Multivariate NTCP Model of Hypothyroidism After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

Multivariate NTCP Model of Hypothyroidism After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

AIRO Breast Cancer Group Best Clinical Practice 2022 Update

Harmonization of breast cancer radiotherapy treatment planning in the Netherlands

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