%0 Journal Article %1 Clark2015a %A Clark, Haley %A Hovan, Allan %A Moiseenko, Vitali %A Thomas, Steven %A Wu, Jonn %A Reinsberg, Stefan %D 2015 %J Med. Phys. %K %N 4 %P 2064--2071 %R 10.1118/1.4915077 %T Regional radiation dose susceptibility within the parotid gland: Effects on salivary loss and recovery %U http://www.ncbi.nlm.nih.gov/pubmed/25832096 http://doi.wiley.com/10.1118/1.4915077 %V 42 %X PURPOSE Xerostomia is one of the most likely late toxic effects of radiotherapy treatment in patients with head-and-neck cancers. Modern treatment techniques can incorporate knowledge of complication risk into treatment plans. To this end, the authors attempt to quantify the regional radiotherapy dose-dependence of salivary output loss and recovery in a prospective study. METHODS Salivary output was collected from patients undergoing radiotherapy treatment for head-and-neck cancers at the BC Cancer Agency between February 2008 and May 2013. Regional dose-dependence (i.e., dose susceptibility) of loss and recovery is quantified using nonparametric (Spearman's rank correlation coefficients, local linear regression) and parametric (least-sum of squares, least-median of squares) techniques. RESULTS Salivary flow recovery was seen in 79 of 102 patients considered (p \textless 0.0001, Wilcoxon sign rank test). Output loss was strongly correlated with left- and right parotid combined dose $\phi$ = min (DL, 45 Gy) + min (DR, 45 Gy), and can be accurately predicted. Median early loss (three months) was 72\% of baseline, while median overall loss (1 yr) was 56\% of baseline. Fitting an exponential model to whole parotid yields dose sensitivities A3m = 0.0604 Gy(-1) and A1y = 0.0379 Gy(-1). Recovery was not significantly associated with dose. Hints of lateral organ sub-segment dose-response dimorphism were observed. CONCLUSIONS Sub-segmentation appears to predict neither loss nor recovery with any greater precision than whole parotid mean dose, though it is not any worse. Sparing the parotid to a combined dose $\phi$ of \textless50 Gy is recommended for a patient to keep ≈40\% of baseline function and thus avoid severe xerostomia at 12 months post-treatment. It seems unlikely that a population's mean recovery will exceed 20\%-30\% of baseline output at 1 yr after radiotherapy treatment using current (whole-organ based) clinical guidelines.

@article{Clark2015a, abstract = {PURPOSE Xerostomia is one of the most likely late toxic effects of radiotherapy treatment in patients with head-and-neck cancers. Modern treatment techniques can incorporate knowledge of complication risk into treatment plans. To this end, the authors attempt to quantify the regional radiotherapy dose-dependence of salivary output loss and recovery in a prospective study. METHODS Salivary output was collected from patients undergoing radiotherapy treatment for head-and-neck cancers at the BC Cancer Agency between February 2008 and May 2013. Regional dose-dependence (i.e., dose susceptibility) of loss and recovery is quantified using nonparametric (Spearman's rank correlation coefficients, local linear regression) and parametric (least-sum of squares, least-median of squares) techniques. RESULTS Salivary flow recovery was seen in 79 of 102 patients considered (p {\textless} 0.0001, Wilcoxon sign rank test). Output loss was strongly correlated with left- and right parotid combined dose $\phi$ = min (DL, 45 Gy) + min (DR, 45 Gy), and can be accurately predicted. Median early loss (three months) was 72{\%} of baseline, while median overall loss (1 yr) was 56{\%} of baseline. Fitting an exponential model to whole parotid yields dose sensitivities A3m = 0.0604 Gy(-1) and A1y = 0.0379 Gy(-1). Recovery was not significantly associated with dose. Hints of lateral organ sub-segment dose-response dimorphism were observed. CONCLUSIONS Sub-segmentation appears to predict neither loss nor recovery with any greater precision than whole parotid mean dose, though it is not any worse. Sparing the parotid to a combined dose $\phi$ of {\textless}50 Gy is recommended for a patient to keep ≈40{\%} of baseline function and thus avoid severe xerostomia at 12 months post-treatment. It seems unlikely that a population's mean recovery will exceed 20{\%}-30{\%} of baseline output at 1 yr after radiotherapy treatment using current (whole-organ based) clinical guidelines.}, added-at = {2023-12-13T01:46:04.000+0100}, author = {Clark, Haley and Hovan, Allan and Moiseenko, Vitali and Thomas, Steven and Wu, Jonn and Reinsberg, Stefan}, biburl = {https://www.bibsonomy.org/bibtex/229f001f679d2677a2e66721ef808709c/admin}, doi = {10.1118/1.4915077}, interhash = {762742f5e91b6de485c70b60824315de}, intrahash = {29f001f679d2677a2e66721ef808709c}, issn = {00942405}, journal = {Med. Phys.}, keywords = {}, mendeley-tags = {parotid}, month = apr, number = 4, pages = {2064--2071}, pmid = {25832096}, timestamp = {2023-12-13T01:46:04.000+0100}, title = {{Regional radiation dose susceptibility within the parotid gland: Effects on salivary loss and recovery}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/25832096 http://doi.wiley.com/10.1118/1.4915077}, volume = 42, year = 2015 }