Parotid gland stem cells: Mini yet mighty

Abstract

Background: Our aim was to evaluate the correlation between the radiation doses to parotid gland (PG) stem cells and xerostomia. Methods: Patients diagnosed with head and neck cancer (HNC) were retrospectively evaluated, and xerostomia inventory (XI) was applied to these patients. PG stem cells were delineated on the treatment planning CT, and the mean doses to the PG stem cells calculated. Results: The total test score and mean doses to bilateral PGs were significantly correlated (r = .34, P = .001), and the mean doses to bilateral PG stem cell niches were significantly correlated with the total test score (r = .32, P = .002). Conclusions: In this study, we found that the mean dose to PG stem cells can predict dry mouth as much as the mean dose to the PG.

Parotid Gland Stem Cell Sparing Radiation Therapy for Patients With Head and Neck Cancer: A Double-Blind Randomized Controlled Trial

“…The parotid glands, the submandibular glands, the oral cavity, and specific regions of the parotid glands were investigated. 8,15,[38][39][40][41][42][43][44][45][46] The next step is prioritization of relevant OARs for treatment optimization, currently often determined using a prospective or retrospective cohort study. However, a major issue in elucidating the role of a potential structure is collinearity between doses to different OARs.…”

“…However, aside from dose to the contralateral SCR region, dose to other OARs, pretreatment xerostomia, and additional clinical risk factors (eg, age, tumor location and classification, and administration of systemic therapy) are also relevant for the development of xerostomia. 8,15,[38][39][40][41][42][43][44][45][46] Therefore, the development of normal tissue complication probability models for the different xerostomia endpoints, considering the role of the SCR region in addition to other risk factors, will contribute to prioritizing the sparing of different OARs and might be an aid for the selection of treatment techniques, such as adaptive radiation therapy or proton therapy. 10,11 Sparing subvolumes of the parotid glands Finally, in other studies, associations between dose to parotid gland subvolumes and parotid function were also investigated (ie, salivary flow and/or xerostomia).…”

The Role of Patient- and Treatment-Related Factors and Early Functional Imaging in Late Radiation-Induced Xerostomia in Oropharyngeal Cancer Patients

“…Nevertheless, the incorporation of voxel-dose parameters does not appear to significantly improve the model’s predictive ability relative to conventional dosimetric parameters [ 28 ]. Moreover, Sari et al recently reported that that D mean to parotid stem cells (located inside the Stenson duct perimeter) had a comparable ability to predict xerostomia than did D mean to entire parotids [ 47 ]. Lastly, the performance of the proposed models was not validated in an independent external cohort, which would have allowed them to demonstrate their robustness and transportability to other settings.…”

Regional Responses in Radiation-Induced Normal Tissue Damage

“…The current clinical approach to minimizing the risk of xerostomia is preservation of salivary function by minimizing the dose to the parotid glands in treatment planning. Several studies have indicated that post-radiotherapy parotid gland function and xerostomia are better predicted by dose to regions or spatial features of the dose distribution [110][111][112][113][114][115]. As mentioned above, a region adjacent to the dorsal edge of the mandible was identified as the best predictor of post-treatment function [110].…”