In:
Frontiers in Oncology, Frontiers Media SA, Vol. 11 ( 2021-4-1)
Abstract:
To investigate the role of half-brain delineation in the prediction of radiation-induced temporal lobe injury (TLI) in nasopharyngeal carcinoma (NPC) receiving intensity-modulated radiotherapy (IMRT). Methods and Materials A total of 220 NPC cases treated with IMRT and concurrent platinum-based chemotherapy were retrospectively analyzed. Dosimetric parameters of temporal lobes, half-brains, and brains included maximum dose (D max ), doses covering certain volume (D V ) from 0.03 to 20 cc and absolute volumes receiving specific dose (V D ) from 40 to 80 Gy. Inter-structure variability was assessed by coefficients of variation (CV) and paired samples t -tests. Receiver operating characteristic curve (ROC) and Youden index were used for screening dosimetric parameters to predict TLI. Dose/volume response curve was calculated using the logistic dose/volume response model. Results CVs of brains, left/right half-brains, and left/right temporal lobes were 9.72%, 9.96%, 9.77%, 27.85%, and 28.34%, respectively. Each D V in temporal lobe was significantly smaller than that in half-brain (P & lt; 0.001), and the reduction ranged from 3.10% to 45.98%. The area under the curve (AUC) of D V and V D showed an “increase-maximum-decline” behavior with a peak as the volume or dose increased. The maximal AUCs of D V s in brain, half-brain and temporal lobe were 0.808 (D 2cc ), 0.828 (D 1.2cc ) and 0.806 (D 0.6cc ), respectively, and the maximal AUCs of V D s were 0.818 (D 75Gy ), 0.834 (V 72Gy ) and 0.814 (V 70Gy ), respectively. The cutoffs of V 70Gy (0.86 cc), V 71Gy (0.72 cc), V 72Gy (0.60 cc), and V 73Gy (0.45 cc) in half-brain had better Youden index. TD5/5 and TD50/5 of D 1.2cc were 58.7 and 80.0 Gy, respectively. The probability of TLI was higher than & gt;13% when V 72Gy & gt;0 cc, and equal to 50% when V 72Gy = 7.66 cc. Conclusion Half-brain delineation is a convenient and stable method which could reduce contouring variation and could be used in NPC patients. D 1.2cc and V 72Gy of half-brain are feasible for TLI prediction model. The dose below 70 Gy may be relatively safe for half-brain. The cutoff points of V 70–73Gy could be considered when the high dose is inevitable.
Type of Medium:
Online Resource
ISSN:
2234-943X
DOI:
10.3389/fonc.2021.599942
Language:
Unknown
Publisher:
Frontiers Media SA
Publication Date:
2021
detail.hit.zdb_id:
2649216-7
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