The Long-Term Recovery of Parotid Glands in Nasopharyngeal Carcinoma Treated by Intensity-Modulated Radiotherapy

Correlation during the extent of surgical resection, oral function and quality of life after tongue cancer surgery: Single-institution study

INTRODUCTION

The extent of surgical resection for tongue tumors is determined by tumor size, potentially affecting oral function and quality of life (QoL). However, the relationship between oral dysfunction and QoL decline due to glossectomy extent remains unexplored. Therefore, these correlations and their predictive value for postoperative QoL decline were elucidated.

METHODS

Patients treated for tongue cancer at our hospital between 2018 and 2022 were categorized by partial, hemi, or subtotal/total glossectomy. Assessments included swallowing function (RSST), articulation (Oral Diadochokinesis (ODK)), mastication, tongue pressure, and oral moisture. QoL was measured using the Oral Health Impact Profile-14 (OHIP-14). Differences within parameters were assessed using Kruskal-Wallis tests, and between-group comparisons via Mann-Whitney U tests. Spearman's correlation analysis examined parameter relationship.

RESULTS

35 patients were evaluated. Significant differences were found in ODK [ta] (p = 0.015), [ka] (p = 0.0006), tongue pressure (p = 0.0001), moisture levels (p = 0.031), OHIP-14 domains: physical disability (p = 0.014) and social disability (p = 0.046). ODK [ta] (PG: 5.95, HG: 5.38, TG: 4.03 times), [ka] (PG: 5.56, HG: 4.78, TG: 3.23 times), and tongue pressure (PG: 32.9, HG: 21.2, TG: 10.3 mmHg) decreased with glossectomy extent, while physical (PG: 0.27, HG: 2.38, TG: 2.00) and social disability (PG: 0.18, HG: 0.94, TG: 1.43) worsened. A significant negative correlation was observed between tongue pressure and social disability (p = 0.013, r = -0.36).

CONCLUSION

Expanding resection significantly impacted postoperative oral function and QoL. Tongue pressure assessment may predict long-term social disability in patient QoL.

Radical Resection of Malignant Tumors of Major Salivary Glands: Is This Possible?

In primary therapy, a universally recognized surgical indication applies to all tumors of the salivary glands. According to the classic rule, radical resection of a head and neck tumor requires clean margins of at least 5 mm, although recent studies have shown that for certain locations, 1 mm may be sufficient. In the surgical resection of a tumor of the salivary glands, especially of the parotid gland, can these rules be respected? Owing to the complex branching and connections of the facial nerve within the parotid gland, even a medium-sized malignant tumor may be in contact with a branch of the nerve, thus raising the question of its preservation. The facial nerve is so important from a functional and aesthetic point of view that it is commonly believed that it should be preserved unless it is incorporated into the tumor. This is a compromise between an oncological resection, that is, the complete excision of the tumor with no residual cancer cells left behind, and quality of life. Almost all authors try to overcome this lack of radicality by indicating postoperative (chemo)radiotherapy. In this article, the pros and cons of nerve preservation will be analyzed by examining the published studies on this topic.

Serial Changes in Parotid Gland Volume and Symptoms After Radiation Therapy in Oropharyngeal Cancer

Objective: To evaluate the serial changes in the volume of the parotid gland and clinical symptoms after a course of radiation therapy (RT) in patients with oropharyngeal cancer. Methods: A total of 33 patients who were diagnosed with oropharyngeal cancer and had been treated with RT or concurrent chemoradiation therapy were evaluated. Parotid gland volumes were measured serially by head and neck computed tomography with contrast-enhanced images before RT, and 6 months, 1 year, and 2 years after RT. Patients also filled out EORTC (European Organization for the Research and Treatment of Cancer) QLQ-C30 questionnaires on the quality of life (QOL) at the same time. This questionnaire included questions about salivary gland function: dry mouth, sticky saliva, and taste disorder. Higher scores on EORTC questionnaire translates to worse QOL. Results: All patients received more than 60 Gy irradiation in total. The mean volume of parotid gland decreased from 23.30 mL before RT to 15.80 mL, 15.93 mL, and 16.67 mL after 6 months, 1 year, and 2 years, respectively (P < 0.001 between pre-RT and all other 3 periods). The scores on the QOL questionnaire were higher (worsened QOL) at all 3 times after radiation than in the pre-RT period. The mean score of QOL increased from pre-RT to 2 years post-RT: "dry mouth" from 1.65 to 2.70, "sticky saliva" from 1.19 to 2.00, and "taste disorder" from 1.12 to 1.94. All 3 of these parameters were correlated with the volume of the parotid gland (P < 0.005 each). Conclusions: The volume of the parotid gland decreases significantly after RT for oropharyngeal cancer and does not recover significantly for at least 2 years. There was a significant correlation between decreased parotid volume and a lower QOL involving salivation.

Evaluating the transcriptional landscape and cell-cell communication networks in chronically irradiated parotid glands

Understanding the transcriptional landscape that results in chronic salivary hypofunction after irradiation will help identify injury mechanisms and develop regenerative therapies. We present scRNA-seq analysis from control and irradiated murine parotid glands collected 10 months after irradiation. We identify a population of secretory cells defined by specific expression of Etv1, which may be an acinar cell precursor. Acinar and Etv1+ secretory express Ntrk2 and Erbb3, respectively while the ligands for these receptors are expressed in myoepithelial and stromal cells. Furthermore, our data suggests that secretory cells and CD4+CD8+T-cells are the most transcriptionally affected during chronic injury with radiation, suggesting active immune involvement. Lastly, evaluation of cell-cell communication networks predicts that neurotrophin, neuregulin, ECM, and immune signaling are dysregulated after irradiation, and thus may play a role in the lack of repair. This resource will be helpful to understand cell-specific pathways that may be targeted to repair chronic damage in irradiated glands.

Effect of nutritional status before radiotherapy on radiation-induced acute toxicities in patients with nasopharyngeal carcinoma

BACKGROUND

To investigate the effect of nutritional status on radiation-induced acute toxicities in nasopharyngeal carcinoma (NPC) patients before radiotherapy.

METHODS

Nutritional status of 228 patients with NPC who received intensity-modulated radiotherapy was retrospectively analyzed by modified nutrition index (m-NI). Cumulative grading score of six common acute toxicities were defined as total score for acute toxicities.

RESULTS

M-NI ≤6 is a risk factor for xerostomia (p = 0.016, OR = 0.208, 95% CI 0.058-0.743), oral mucositis (p = 0.016, OR = 0.287, 95% CI 0.104-0.793), dysgeusia (p = 0.001, OR = 0.028, 95% CI 0.004-0.217), and dysphagia (p = 0.015, OR = 0.251, 95% CI 0.083-0.764) as well in patients with NPC. Total score of radiation-induced acute toxicities of patients with malnutrition (13.6 ± 1.7) was significantly higher than that of patients with normal nutrition (12.0 ± 2.4) (t = -5.464, p < 0.001).

CONCLUSIONS

NPC patients with malnutrition before radiotherapy develop more serious dysgeusia, oral mucositis, dysphagia, and xerostomia after intensity-modulated radiotherapy.

The dose limits of teeth protection for patients with nasopharyngeal carcinoma undergoing radiotherapy based on the early oral health-related quality of life

Radiation-related teeth damage is a common complication in nasopharyngeal carcinoma (NPC) patients undergoing radiotherapy (RT) that seriously affects their oral health-related quality of life (OHRQoL). However, few studies have focused on protecting teeth function. This study aimed to calculate dental dose limits based on OHRQoL. Analysis was performed on 96 NPC patients who received RT (all received routine pre-radiotherapy dental interventions in our department). Based on the General Oral Health Assessment Index (GOHAI), OHRQoL was assigned into poor (<46) and good condition groups (≥46). The binary logistic regression analysis model was used for single-factor and multivariate analyses to identify the independent factors affecting OHRQoL. The cut-off value of dose received by teeth was obtained by drawing a receiver operating characteristic curve. NPC patients experienced a decline in OHRQoL following RT (P < 0.05). Univariate analysis of GOHAI revealed that the average dose of maxillary anterior teeth, the average dose received by the oral cavity, tumor volume (GTVnx), and liking of the sweet food all affected GOHAI (P < 0.05). Multivariate analysis indicated that the average dose of maxillary anterior teeth and liking sweet food were independent factors that influenced the OHRQoL of NPC patients with RT. When the average dose received by maxillary anterior teeth is greater than 28.78 Gy, and there is a tendency in sweet food, the OHRQoL will deteriorate. NPC patients who received RT had a better OHRQoL if the average dose to maxillary anterior teeth was limited to less than 28.78 Gy and the intake of high-sugar foods was reduced.

Acquired unilateral alopecia after arterial infusion chemotherapy in a recurrent nasopharyngeal carcinoma

Background

Intractable nasopharyngeal hemorrhage is a severe complication with high mortality rate in patients with radiation therapy (RT) for nasopharyngeal carcinoma (NPC) that requires emergency treatment. Quite a few of them combine with tumor recurrence. Treatment planning for these patients is extremely difficult for oncologists, and effective treatments are lacking.

Case

A 42‐year‐old man had a history of recurrent NPC that was treated with 2 cycles of chemoradiotherapies from 2017 to 2019. Five months after the second round of chemoradiotherapy, an episode of massive nasal bleeding occurred. As positron emission tomography (PET) scan revealed tumor recurrence in the left wall of nasopharynx, superselective embolization and subsequent intra‐arterial infusion (IA, 4 times of cisplatin 60 mg + fluorouracil 1.0 g) were performed to stop bleeding and achieve tumor control. To date, the disease‐free survival time has been over 1 year. No tumor recurrence or rebleeding is found except for alopecia on the left side.

Conclusions

Interventional radiology is important and effective in the treatment of recurrent NPC for both massive nasal bleeding and tumor control. However, the unique complication of unilateral alopecia should not be ignored.

Research Value of Intensity Modulated Radiation Therapy in Alleviating Parotid Gland Function Injury in Patients with Stage N0 Nasopharyngeal Carcinoma from Physical and Dosimetric Aspects

Objective

To study the feasibility of intensity modulated radiation therapy (IMRT) for stage N₀ nasopharyngeal carcinoma (NPC) and its parotid gland (PG) function preservation from physical and dosimetric aspects.

Methods

All the clinical data of 77 patients with pathologically confirmed T_1-4N₀M₀ NPC who received radiotherapy between July 2017 and October 2019 in the Radiotherapy Center of Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University were analyzed retrospectively. Three-dimensional conformal radiotherapy (3D-CRT) and IMRT were used in 35 and 42 cases, respectively. The treatment efficiency and the dosimetry differences of the PG in the intensity modulation plan were compared between groups. Quantitative monitoring of 99mTc radionuclide imaging of PG was performed before, at the end of, and 3, 6, and 12 months after radiotherapy. The degree of PG function injury and xerostomia was compared between groups at the end of radiotherapy and 12 months later.

Results

Higher minimal, maximal, and average irradiation doses of PG were determined in 3D-CRT-treated patients compared with IMRT-treated cases (P < 0.05). Compared with before radiotherapy, the PG uptake index (UI) and excretion index (EI) of both cohorts of patients decreased to varying degrees at the end of radiotherapy, with PG function injury and xerostomia symptoms observed in all cases but with no obvious difference between groups (P > 0.05). To a certain extent, the PG function recovered and the xerostomia symptoms relieved in both groups 12 months after radiotherapy, with better improvements in IMRT group versus 3D-CRT group.

Conclusion

IMRT has similar short-term efficacy to 3D-CRT in treating patients with stage N₀ NPC, but it can effectively reduce the dose of PG radiotherapy and protect the PG function on the premise of ensuring sufficient tumor coverage and dose, showing certain dosimetry advantages.