Ipsilateral Parotid Gland Research Articles

Anatomical and dosimetric variations during volumetric modulated arc therapy in patients with locally advanced nasopharyngeal carcinoma after induction therapy: Implications for adaptive radiation therapy

PurposeTo investigate anatomical and dosimetric changes during volumetric modulated arc therapy (VMAT) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) after induction therapy (IT) and explore characteristics of patients with notable variations. Materials and methodsFrom July 2021 to June 2023, 60 LA-NPC patients undergoing VMAT after IT were retrospectively recruited. Adaptive computed tomography (aCT), reconstructed from weekly cone-beam computed tomography(CBCT), facilitates recontouring and planning transplantation. Volume, dice similarity coefficients, and dose to target volumes and organs at risk(OARs) on planning CT(pCT) and aCT were compared to identify changing patterns. Multivariate logistic regression was used to investigate risk factors. ResultsThe volumes of PGTVnasopharynx (PGTVp), PGTVnode (PGTVn), ipsilateral and contralateral parotid glands decreased during VMAT, with reductions of 2.25 %, 6.98 %, 20.09 % and 18.00 %, respectively, at 30 fractions from baseline (P < 0.001). After 25 fractions, D99 and D95 of PGTVn decreased by 7.94 % and 4.18 % from baseline, respectively, while the Dmean of ipsilateral and contralateral parotid glands increased by 7.80 % and 6.50 %, marking the peak rates of dosimetric variations (P < 0.001). The dosimetric fluctuations in PGTVp, the brainstem, and the spinal cord remained within acceptable limits. Furthermore, an initial BMI ≥ 23.5 kg/m2 and not-achieving objective response (OR) after IT were regarded as risk factors for a remarkable PGTVn dose reduction in the later stages of VMAT. ConclusionsReplanning for post-IT LA-NPC patients appears reasonable at 25F during VMAT. Patients with an initial BMI ≥ 23.5 kg/m2 and not-achieving OR after IT should be considered for adaptive radiation therapy to stabilize the delivered dose.

Clinical features and prognosis of parotid metastasis of breast cancer: retrospective analysis of 57 cases.

Parotid gland metastases originating from breast origin are extremely rare, with their clinical presentation, therapeutic approaches, and prognostic indicators remaining to be elucidate. A comprehensive retrospective review was conducted, analyzing the clinical characteristics and prognostic factors of 57 patients diagnosed with parotid metastasis of breast cancer in the existing literature. Notably, our study included two unique cases of patients who developed contralateral and ipsilateral parotid metastases, occurring 5 years and 32 years respectively after primary surgery. This analysis aimed to provide a deeper understanding of the disease presentation and identify potential prognostic indicators. The primary clinical manifestation presented in breast cancer patients with parotid metastases was painless masses in the parotid glands, synchronously or metachronously occurred with primary breast tumors. The predominant pathological subtype among these patients was invasive ductal carcinoma. Out of the 57 patients studied, 24 (42.1%) exhibited metastases solely in the ipsilateral parotid gland, while 18 cases (31.6%) involved either the contralateral or bilateral parotid gland. Patients may solely exhibit metastasis in the parotid gland, or they may present with concurrent multiple metastases in other organs. Patients who suffered from parotid metastases, either merely or accompanied with bone-only metastasis, exhibited significantly longer overall survival (OS) rates compared to those who had concomitant metastases in other organs (1.23 ± 0.26 years vs 4.46 ± 0.77 years, P=0.046). While no statistically significant differences in OS were observed among patients presenting with metastases in the ipsilateral, contralateral, or bilateral parotid glands, a notable variance could be discerned from the Kaplan-Meier curve analysis. Additionally, no significant difference in survival was exhibited between patients with different interval of progression from primary breast sites to initial diagnosis of parotid metastases (uDF), nor for patients who were treated with surgery or palliative therapy. Parotid metastasis, a rare and distinctive form of breast cancer metastasis, demands particular scrutiny in patients exhibiting metastasis to multiple organs or contralateral or bilateral parotid glands.

An Observational Dosimetric Study in Definitively Treated Primary Head and Neck Cancers: To Assess the Effect of Weight Loss and Change in Lateral Neck Dimensions on the Difference Between Dose Planned and Received by the Parotid(s) and Correlation with Adaptive Radiation Therapy

The head and neck cancer (HNC) literature is rife with reports of differences in planned versus actual radiation doses to the parotid gland (PG) due to changes in anatomy during the course of radiation therapy. We prospectively studied and quantified changes in planned and delivered doses due to weight loss and changes in lateral neck dimensions. Sixty patients were enrolled in this prospective non-randomized observational study. The inclusion criterion was having a newly diagnosed, histologically proven squamous cell carcinoma of HNC. Weight loss (WL) and change in lateral neck dimensions (LND) were assessed weekly, and new hybrid plans were generated using interval replanning CT scans. Dose variations were monitored and extrapolated for replanning CT scans and correlated with WL and change in LND. The Pearson correlation coefficients for WL and difference in Dmean of ipsilateral and contralateral PG was 0.3292 (P = .0124) and 0.4232 (P = .0010), respectively. There was significantly higher change in the Dmean of bilateral PG (Ipsilateral(I) > contralateral(C)) in patients who experienced WL of >5%. Change in LND correlated with difference in Dmean of ipsilateral PG at 0.4829 (P = .0001) and difference in D50 at 0.4146 (P < .0013). Contralateral PG correlated with difference in Dmean at 0.5952 (P < .0001). The difference in Dmean for ipsilateral PG was 1.8535 Gy for those showing reduction in LND of >1 cm compared with 0.8596 Gy (P = .0091) for those who had ≤1 cm reduction in LND. Either WL of >5% or reduction in LND of >1 cm can be used as an external parameter to help select patients who might benefit most from replanning and adaptive radiation therapy.

Cone-beam computed tomography-guided online adaptive radiotherapy for pharyngeal cancer with whole neck irradiation: dose-volume histogram analysis between adapted and scheduled plans.

The present study aimed to evaluate whether an adapted plan with Ethos™ could be used for pharyngeal cancer. Ten patients with pharyngeal cancer who underwent chemoradiotherapy with available daily cone-beam computed tomography (CBCT) data were included. Simulated treatments were generated on the Ethos™ treatment emulator using CBCTs every four to five fractions for two plans: adapted and scheduled. The simulated treatments were divided into three groups: early (first-second week), middle (third-fourth week), and late (fifth-seventh week) periods. Dose-volume histogram parameters were compared for each period between the adapted and scheduled plans in terms of the planning target volume (PTV) (D98%, D95%, D50% and D2%), spinal cord (Dmax and D1cc), brainstem (Dmax) and ipsilateral and contralateral parotid glands (Dmedian and Dmean). The PTV D98%, D95% and D2% of the adapted plan were significantly higher than those of the scheduled plans in all periods, except for D98% in the late period. The adapted plan significantly reduced the spinal cord Dmax and D1cc compared with the scheduled plan in all periods. Ipsilateral and contralateral parotid glands Dmean of the adapted plan were lower than those of scheduled plan in the late period. In conclusion, the present study revealed that the adapted plans could maintain PTV coverage while reducing the doses to organs at risk in each period compared with scheduled plans.

Predicting the need for a replan in oropharyngeal cancer: A radiomic, clinical, and dosimetric model.

Patients with oropharyngeal cancer (OPC) treated with chemoradiation can experience weight loss and tumor shrinkage, altering the prescribed treatment. Treatment replanning ensures patients do not receive excessive doses to normal tissue. However, it is a time- and resource-intensive process, as it takes 1 to 2 weeks to acquire a new treatment plan, and during this time, overtreatment of normal tissues could lead to increased toxicities. Currently, there are limited prognostic factors to determine which patients will require a replan. There remains an unmet need for predictive models to assist in identifying patients who could benefit from the knowledge of a replan prior to treatment. We aimed to develop and evaluate a CT-based radiomic model, integrating clinical and dosimetric information, to predict the need for a replan prior to treatment. A dataset of patients (n=315) with OPC treated with chemoradiation was used for this study. The dataset was split into independent training (n=220) and testing (n=95) datasets. Tumor volumes and organs at risk (OARs) were contoured on planning CT images. PyRadiomics was used to compute radiomic image features (n=1218) on the original and filtered images from each of the primary tumor, nodal volumes, and ipsilateral and contralateral parotid glands. Nine clinical features and nine dose features extracted from the OARs were collected and those significantly (p<0.05) associated with the need for a replan in the training dataset were used in a baseline model. Random forest feature selection was applied to select the optimal radiomic features to predict replanning. Logistic regression, Naïve Bayes, support vector machine, and random forest classifiers were built using the non-correlated selected radiomic, clinical, and dose features on the training dataset and performance was assessed in the testing dataset. The area under the curve (AUC) was used to assess the prognostic value. A total of 78 patients (25%) required a replan. Smoking status, nodal stage, base of tongue subsite, and larynx mean dose were found to be significantly associated with the need for a replan in the training dataset and incorporated into the baseline model, as well as into the combined models. Five predictive radiomic features were selected (one nodal volume, one primary tumor, two ipsilateral and one contralateral parotid gland). The baseline model comprised of clinical and dose features alone achieved an AUC of 0.66 [95% CI: 0.51-0.79] in the testing dataset. The random forest classifier was the top-performing radiomics model and achieved an AUC of 0.82 [0.75-0.89] in the training dataset and an AUC of 0.78 [0.68-0.87] in the testing dataset, which significantly outperformed the baseline model (p=0.023, testing dataset). This is the first study to use radiomics from the primary tumor, nodal volumes, and parotid glands for the prediction of replanning for patients with OPC. Radiomic features augmented clinical and dose features for predicting the need for a replan in our testing dataset. Once validated, this model has the potential to assist physicians in identifying patients that may benefit from a replan, allowing for better resource allocation and reduced toxicities.

Dosimetric comparison of postoperative interstitial high-dose-rate brachytherapy and modern external beam radiotherapy modalities in tongue and floor of the mouth tumours in terms of doses to critical organs.

The aim of the study was to dosimetrically compare interstitial high-dose-rate (HDR) brachytherapy (BT) and modern external beam radiotherapy modalities, as volumetric modulated arc therapy (VMAT) and stereotactic radiotherapy with Cyberknife (CK) of tumours of the tongue and floor of the mouth in terms of dose to the critical organs. In National Institute of Oncology, Budapest, between March 2013 and August 2022 twenty patients (11 male/9 female) with stage T1-3N0M0 tongue (n = 14) and floor of mouth (n = 6) tumours received postoperative radiotherapy because of close/positive surgical margin and/or lymphovascular and/or perineural invasion. High-dose-rate interstitial brachytherapy applying flexible plastic catheters with a total dose of 15 × 3 Gy was used for treatment. In addition to BT plans VMAT and stereotactic CK plans were also made in all cases, using the same fractionation scheme and dose prescription. As for the organs at risk, the doses to the mandible, the ipsilateral and the contralateral salivary glands were compared. The mean volume of the planning target volume (PTV) was 12.5 cm3, 26.5 cm3 and 17.5 cm3 in BT, VMAT and CK techniques, respectively, due to different safety margin protocols. The dose to the mandible was the most favourable with BT, as for the salivary glands (parotid and submandibular) the CK technique resulted in the lowest dose. The highest dose to the critical organs was observed with the VMAT technique. The mean values of D2cm3 and D0.1cm3 for the critical organs were as follows for BT, VMAT and CK plans: 47.4% and 73.9%, 92.2% and 101.8%, 68.4% and 92.3% for the mandible, 4.8% and 6.7%, 7.3% and 13.8%, 2.3% and 5.1% for the ipsilateral parotid gland, 3.5% and 4.9%, 6.8% and 10.9%, 1.5% and 3.3% for the contralateral parotid gland, 7.3% and 9.4%, 9.0% and 14.3%, 3.6% and 5.6% for the contralateral submandibular gland. The present results confirm that BT, despite being an invasive technique, is dosimetrically clearly beneficial in the treatment of oral cavity tumours and is a modality worth considering when applying radiotherapy, not only as definitive treatment, but also postoperatively. The use of the CK in the head and neck region requires further investigation.

Dosimetric and radiobiological analyses of a de-escalation strategy for elective nodal regions in human papillomavirus-associated oropharyngeal cancer

IntroductionIn this simulation study, we examined the effects of a de-escalation strategy with a reduced dose to subclinical nodal regions in patients with human papillomavirus (HPV)-associated oropharyngeal carcinoma (OPC). MethodsWe created two patterns of intensity-modulated radiotherapy for 16 patients with HPV-associated OPC. In the standard and de-escalation plans, the initial field including elective nodal regions received 46 and 30 Gy, followed by 20 and 36 Gy to the cutdown field, respectively. Comparison metrics were set for each organ at risk (OAR). We compared these metric values and the probability of adverse effects based on the normal tissue complication probability (NTCP) model between the two plans. ResultsBoth plans generally met the dose constraints for the targets and all OAR. Among the comparison metrics, the mean doses to the brain, pharyngeal constrictor muscle, thyroid, and skin and the dose to a 1 % volume of the skin were higher in the standard plan than in the de-escalation plan (P = 0.031, 0.007, < 0.001, < 0.001, and 0.006, respectively). NTCP analyses revealed that the probability of adverse effects in the ipsilateral parotid gland and thyroid was higher in the standard plan than in the de-escalation plan (standard vs. de-escalation plans: ipsilateral parotid gland, 6.4 % vs. 5.0 %, P = 0.016; thyroid, 3.3 % vs. 0.5 %, P < 0.001). ConclusionsA de-escalation strategy with elective nodal regions is a promising treatment to prevent a decline in the quality of life in patients with HPV-associated OPC, particularly xerostomia, dysphagia, and hypothyroidism.

Online Adaptive Radiotherapy for Pharyngeal Cancer: Dose-Volume Histogram Analysis between Adapted and Scheduled Plan

The present study aimed to evaluate whether online adapted plan with artificial intelligence (AI) driven work flow could be used in clinical settings with variable changes of the targets and organs at risk (OARs) for pharyngeal cancer. Ten patients with pharyngeal cancer who underwent chemoradiotherapy at our institution between January and July 2020 were included for the analysis. All patients had been previously aligned daily with cone-beam computed tomography (CBCT) and treated by O-ring Linac. A simulated treatment was performed on the treatment emulator. Weekly fractions, once in every 4-5 fractions, were simulated in the treatment emulator for each patient using their previous on-treatment CBCTs. The dataset was divided into three groups according to the treatment period (1st-2nd week, 20 CBCTs), middle (3rd-4th week, 20 CBCTs), and late (5th-7th week, 30 CBCTs) period. In the present study, all of reference plan generation in treatment emulator were created on the initial plans of two-step method using 12 equidistant field IMRT. The prescribed dose was 70 Gy in 35 fractions and normalized to the dose of 68.6 Gy (98% dose) to 95% of the planning target volume (PTV). The adaptation process on treatment emulator includes auto-segmentation of daily anatomy, calculation of the dose in scheduled plans using the same monitor units and optimization and calculation of the dose in adapted plan. Dose-volume histogram (DVH) parameters between adapted and scheduled plans in terms of PTV (D98%, D95%, D50% and D2%), spinal cord (Dmax and D1cc), brain stem (Dmax), ipsilateral and contralateral parotid glands (Dmedian and Dmean) were evaluated in each period. D98% of PTV of adapted plan was significantly higher than that of scheduled plan in early and middle period (p = 0.02 and <0.01, respectively). D95% of PTV of adapted plan was significantly higher than that of scheduled plan in all periods (p<0.01). D2% of PTV of adapted plan was significantly lower than that of scheduled plan in all periods (p = 0.04, 0.04 and 0.02 in each period, respectively). There was not significant difference in D50% of PTV between adapted and scheduled plan in all periods. In terms of OARs, Dmax of spinal cord of adapted plan was significantly lower than that of scheduled plan in all periods (p<0.01). Similarly, D1cc of spinal cord of adapted plan was lower than that of scheduled plan. Dmean of ipsilateral and contralateral parotid glands of adapted plan were lower than those of scheduled plan in the late period (p<0.01 and 0.03, respectively). The present study revealed that adapted plan with AI driven work flow could create dosimetrically better plans for pharyngeal cancer compared to scheduled plan. It was suggested that online adaptive radiotherapy could be necessary to maintain PTV coverage while reducing the dose to OARs in all periods for pharyngeal cancer.

Comparison of Dynamic Trajectory Radiotherapy and Volumetric Modulated Arc Therapy for Loco-Regionally Advanced Oropharyngeal Cancer

Dynamic trajectory radiotherapy (DTRT) extends volumetric modulated arc therapy (VMAT) with dynamic table and collimator rotation. We investigate the potential benefit of DTRT over VMAT with respect to organ-at-risk (OAR) sparing for patients with loco-regionally advanced oropharyngeal cancer (OPC). We created DTRT and VMAT plans for 46 cases with prescribed doses of 50-70 Gy (2 Gy fractions, sequential boost) using 6 MV flattened beam on c-arm Linacs. For DTRT: case-specific collision avoidance maps were created and gantry-table paths were determined based on contoured structures to minimize fractional target/OAR overlap in beam's eye view. Gantry-collimator paths minimized field width in the leaf-travel direction. DTRT paths were imported in a research version of a commercial treatment planning system for intensity modulation optimization using the same optimizer and dose calculation algorithms as for VMAT. Plans at each dose level were normalized with 100% of the prescribed dose to 95% of the planning target volume (PTV). PTV coverage and OAR sparing for DTRT and VMAT were compared using Wilcoxon matched-pair signed rank test (5% significance level). The correlation between the fractional OAR/PTV50Gy volume overlap and difference in OAR Dmean between the two techniques was evaluated using Spearman's correlation coefficient. Plans at each dose level were all acceptable and had D0.03cc<110% prescription dose (difference between DTRT and VMAT were not statistically significant). In the combined plans, PTV50Gy D95% and D98% and PTV70Gy D95% were significantly higher with DTRT compared to VMAT. Differences in PTV66Gy coverage and PTV70Gy D5% were not statistically significant. Mean Dmean to the contralateral (CL) parotid gland was 13.99 / 15.28 Gy for DTRT / VMAT respectively, it was 25.75 / 28.05 Gy for the CL submandibular gland, 44.88 / 45.82 Gy for the pharynx and 30.90 / 33.93 Gy for the oral cavity (all with p<.001). Mean Dmean to the ipsilateral (IL) parotid gland was 29.00 / 29.28 Gy for DTRT / VMAT respectively (p = .77) and 57.71 / 57.91 Gy for the IL submandibular gland (p = .99). Significantly higher doses were observed with DTRT than with VMAT for the optical and auditory OARs and for the brain, but well below the clinical goals. The difference in Dmean (VMAT-DTRT) was negatively correlated to the fractional OAR/PTV50Gy overlap for the CL parotid and submandibular gland and the IL submandibular gland (r = -0.55 to -0.51, p<.001) but not for IL parotid gland (r = -0.17, p = .26), oral cavity (r = -0.13, p = .41) or pharynx (r = -011, p = .47). For at least the same target coverage, DTRT statistically significantly improves sparing for OARs related to salivary and swallowing functions compared to state-of-the-art VMAT. The advantage of DTRT decreases with increasing fractional OAR/PTV50Gy volume overlap for some salivary glands but not for pharynx or oral cavity. DTRT is promising to reduce treatment-related toxicity for patients with OPC.

Predicting late radiation-induced xerostomia in nasopharyngeal carcinoma based on radiomics features extracted from T2WI images of parotids

ObjectiveTo explore the value of radiomics features extracted from the T2-weighted imaging (T2WI) images of parotids in predicting late radiation-induced xerostomia in nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). MethodsA retrospective analysis was conducted for 123 NPC patients who received RT at the Affiliated Tumour Hospital of Xinjiang Medical University from January 2019 to March 2021. All the patients underwent MRI pre-RT and post-RT. They were randomly divided into a training set and a testing set at a ratio of 4:1 using a random number table, with the former and the latter comprising 98 and 25 cases, respectively. The ipsilateral parotid gland (iPG) and the contralateral parotid gland (cPG) were delineated on T2WI images pre-RT and post-RT as regions of interest (ROIs). A total of 851 radiomics features were extracted from each ROI. Spearman analysis was used to remove redundant features, and the recursive feature elimination (RFE) method was then used to determine useful features. Using radiomics features extracted from images pre-treatment, images post-treatment, and differences between images pre- and post-treatment, this study constructed three radiomic models, namely the pre-treatment radiomics model (preRT), the post-treatment radiomics model (postRT), and the delta-radiomics model (DeltaRT). Then, this study plotted the receiver operating characteristic (ROC) curves based on the late radiation-induced xerostomia grades of patients post-RT. Furthermore, the models’ effectiveness and performance in predicting late radiation-induced xerostomia and advanced radioactive xerostomia was evaluated. In addition, the area under the curve (AUC), sensitivity, specificity, accuracy, precision, and negative predictive value (NPV) were calculated. ResultsAmong the features extracted from bilateral parotid glands (PGs), 20 were determined pre-RT (six from iPG and 14 from cPG), 19 were determined post-RT (six from iPG and 13 from cPG), and 20 were derived from the DeltaRT (20 from cPG). The PGs pre-RT and post-RT in the training set had AUCs of 0.902 (95% CI: 0.895–0.909) and 0.761 (95% CI: 0.744–0.778), respectively, while those in the testing set had AUCs of 0.740 (95% CI: 0.504–0.983) and 0.701 (95% CI: 0.478–0.924), respectively. In contrast, the AUC of the cPG derived from the DeltaRT was 0.867 (95% CI: 0.856–0.878) in the training set and 0.851 (95% CI: 0.697–0.999) in the testing set. ConclusionsThere are significant correlations between radiomics features extracted from MRI T2WI images of parotids and late radiation-induced xerostomia in NPC patients. Among the radiomics features, the changes in cPG features pre-RT and post-RT have higher accuracy in predicting late radiation-induced xerostomia.

Mid-treatment 18F-FDG PET imaging changes in parotid gland correlates to radiation-induced xerostomia

BackgroundThe aim of this study was to measure functional changes in parotid glands using mid-treatment FDG-PET/CT and correlate early imaging changes to subsequent xerostomia in mucosal head and neck squamous cell carcinoma patients undergoing radiotherapy. Materials and Methods56 patients from two prospective imaging biomarker studies underwent FDG-PET/CT at baseline and during radiotherapy (week 3). Both parotid glands were volumetrically delineated at each time point. PET parameter SUVmedian were calculated for ipsilateral and contralateral parotid glands.Absolute and relative change (Δ) in SUVmedian were correlated to moderate-severe xerostomia (CTCAE grade ≥ 2) at 6 months. Four predictive models were subsequently created using multivariate logistic regression using clinical and radiotherapy planning parameters. Model performance was calculated using ROC analysis and compared using Akaike information criterion (AIC) Results29 patients (51.8%) developed grade ≥ 2 xerostomia. Compared to baseline, there was an increase in SUVmedian at week 3 in ipsilateral (8.4%) and contralateral (5.5%) parotid glands. Increase in ipsilateral parotid Δ SUVmedian (p = 0.04) and contralateral mean parotid dose (p = 0.04) were correlated to xerostomia.The reference ‘clinical’ model correlated to xerostomia (AUC 0.667, AIC 70.9). Addition of ipsilateral parotid Δ SUVmedian to the clinical model resulted in the highest correlation to xerostomia (AUC 0.777, AIC 65.4). ConclusionOur study shows functional changes occurring in the parotid gland early during radiotherapy. We demonstrate that integration of baseline and mid-treatment FDG-PET/CT changes in the parotid gland with clinical factors has the potential to improve xerostomia risk prediction which could be utilised for personalised head and neck radiotherapy.

MRI findings of sporadic/simple lymphoepithelial cyst of the parotid gland.

This study aimed to determine the MRI features of sporadic/simple lymphoepithelial cyst (SLEC) of the parotid gland. Ten patients (seven men, three women; mean age, 60years; age range, 38-77years) with histopathologically and clinically proven SLEC of the parotid gland who underwent MRI before surgical resection were enrolled in this study. No enrolled patient had HIV infection or Sjögren syndrome. MRI findings of SLEC were retrospectively assessed. We confirmed 10 SLECs larger than 10mm with a mean maximum diameter of 26.6mm (range, 12-42mm). Nine patients (90%) had a single cyst, and one (10%) had a large cyst accompanied by small cysts (<10mm) within the ipsilateral parotid gland. Eight SLECs (80%) were unilocular, and two (20%) were bilocular, with complete septa. Among seven SLECs (70%) with internal septa, five unilocular SLECs (50%) had incomplete septa. Six SLECs (60%) had eccentric cyst wall thickening, and five (50%) were surrounded by small solid nodules that were isointense relative to lymph node. On T1-weighted images, all cyst contents were homogeneously hyperintense relative to cerebrospinal fluid. SLECs of the parotid gland are usually single unilocular lesions. Internal septa, eccentric cyst wall thickening, and small solid nodules surrounding the lesion were often observed. Cyst contents are always homogeneously hyperintense on T1-weighted images.

Endoscopic resection of type D trigeminal schwannoma through nasal sinus approach

Objective: To examine the feasibility and surgical approach of removing type D trigeminal schwannoma through nasal cavity and nasal sinus under endoscope. Methods: Eleven patients with trigeminal schwannoma who were treated in the Department of Otorhinolaryngology, Qilu Hospital of Shandong University from December 2014 to August 2021 were analyzed retrospectively in this study. There were 7 males and 4 females, aged (47.5±13.5) years (range: 12 to 64 years). The neoplasm involved the pterygopalatine fossa, infratemporal fossa, ethmoidal sinus, sphenoid sinus, cavernous sinus, and middle cranial fossa. The size of tumors were between 1.6 cm×2.0 cm×2.0 cm and 5.7 cm×6.0 cm×6.0 cm. Under general anesthesia, the tumors were resected through the transpterygoid approach in 4 cases, through the prelacrimal recess approach in 4 cases, through the extended prelacrimal recess approach in 2 cases, and through the endoscopic medial maxillectomy approach in 1 case. The nasal endoscopy and imaging examination were conducted to detect whether neoplasm recurred or not, and the main clinical symptoms during follow-up. Results: All the surgical procedures were performed under endonasal endoscope, including Gross total resection in 10 patients. The tumor of a 12-year-old patient was not resected completely due to huge tumor size and limited operation space. One patient was accompanied by two other schwannomas located in the occipital region and the ipsilateral parotid gland region originating from the zygomatic branch of the facial nerve, both of which were removed concurrently. After tumor resection, the dura mater of middle cranial fossa was directly exposed in the nasal sinus in 2 cases, including 1 case accompanied by cerebrospinal fluid leakage which was reconstructed by a free mucosal flap obtained from the middle turbinate, the other case was packed by the autologous fat to protect the dura mater. The operation time was (M(IQR)) 180 (160) minutes (range: 120 to 485 minutes). No complications and deaths were observed. No recurrence was observed in the 10 patients with total tumor resection during a 58 (68) months' (range: 10 to 90 months) follow-up. No obvious change was observed in the facial appearance of all patients during the follow-up. Conclusion: Type D trigeminal schwannoma involving pterygopalatine fossa and infratemporal fossa can be removed safely through purely endoscopic endonasal approach by selecting the appropriate approach according to the size and involvement of the tumor.

Point Shear Wave Elastography in Diagnosis and Follow-Up of Salivary Gland Affection after Head and Neck Cancer Treatment.

Therapies of head and neck squamous cell carcinoma (HNSCC), particularly irradiation and chemotherapy (C/RT), can affect salivary glands to some extent. Recent studies suggest that point shear wave elastography (pSWE) is well suited for the diagnosis and rating of homogenous damage to parenchymatous organs. The purpose of this study was to assess the value of this sonographic modality as a tool for the evaluation both of salivary gland affection after HNSCC therapy and the effect of a salivary replacement therapy based on liposomes. A total of 69 HNSCC patients were included in this study. All patients had finished cancer treatment and attended regular follow-up. pSWE values of ipsi- and contralateral parotid (PG) and submandibular glands (SMG) were obtained in a standardized manner and compared to those of a healthy control (HC) group. After a two months treatment with a liposomal saliva replacement therapy pSWE quantification was performed again. Ipsi- and contralateral salivary glands suffer under standard HNSCC tumor therapy. Here, the ipsilateral parotid gland (PG) is primarily affected. Therefore, a sequence of manifestation (surgery &lt; surgery plus adjuvant C/RT &lt; primary C/RT) is comprehensible, evaluated by pSWE measurements. The examination of all glands and statistical analysis of the values compared to controls resulted in an pSWE cutoff value for affected glandular tissue of &gt;2 m/s. Using a liposomal saliva replacement therapy, pSWE values of the ipsilateral PG can be improved, although the level of HC could not be restored.

Multiple synchronous neoplasms in the ipsilateral parotid gland: case series

Multiple synchronous neoplasms in the ipsilateral parotid gland are very rare. We intend to analyze the clinical characteristics and treatment results of multiple synchronous neoplasms in the ipsilateral parotid gland managed at our hospital. The study included 21 patients of multiple synchronous neoplasms in the ipsilateral parotid gland from January 2010 to December 2020. Twenty-one cases of multiple synchronous neoplasms in the ipsilateral parotid gland were identified among 994 cases of parotid surgery, with a frequency of 2.1%. Multiple synchronous neoplasms in the ipsilateral parotid gland occurred in all males and one female. Except for one case, all of them involved histopathologic neoplasms. Warthin tumor (n=19, 90.5%) was the most common. Among 21 lesions, there were 9 patients of right parotid gland, 4 patients of left parotid gland, and 4 patients of bilateral parotid gland. The main symptoms were slowly enlarging mass within the parotid gland (n=20), followed by incidental detection (n=1). Clinicians should be aware of the possibility of multiple synchronous neoplasms in the ipsilateral parotid gland. Preoperative imaging tests, clinical examinations, and careful palpation during surgery are important for accurate diagnosis and treatment.

Study on CT features of congenital branchial cleft anomaly in children

Objective:To summarize the CT features of congenital branchial cleft anomaly in children, to reduce misdiagnosis and improve surgical strategy. Methods:This study enrolled 323 pediatric patients with congenital first branchial cleft anomaly, congenital second branchial cleft anomaly and congenital piriform sinus fistula confirmed by surgery and post-operative histopathology, who was admitted to Shanghai Children's hospital from August 2014 to January 2021., CT imaging data were retrospectively analyzed. Results:A total of 323 children with congenital branchial cleft deformity were included. There were 145 males and 178 females, aged from 22 days to 15 years. 119（119/323, 36.8%） cases were diagnosed as congenital first branchial cleft anomaly. Among them, 96 cases（96/119, 80.67%） were related to the wall of external auditory canal, and 89 cases（89/119, 74.78%） were related to parotid gland. The positive rate of CT examination was 87.4%（104/119）. 57 cases（57 / 323, 17.6%） had congenital second branchial cleft anomaly. Among them, 46 cases（46/57, 80.7%） were related to submandibular gland. The positive rate of CT examination was 84.2%（48/57）. 147 cases（147/323, 45.5%） had congenital piriform sinus fistula, in which 129 cases（129/147, 87.8%） were related to thyroid. The positive rate of CT was 89.1%（131/147）. Conclusion:The CT findings of congenital first branchial cleft anomaly are characterized by lesions in the inferior and/or posterior wall of ipsilateral external auditory canal and parotid gland. The CT features of congenital second branchial cleft anomaly are that the lesion is located on the ipsilateral submandibular gland （posterior and medial）. The CT features of congenital piriform sinus fistula are that the focus is located on the dorsal side of the upper pole of the lateral lobe of the thyroid gland.

The First Prognostic Tool to Estimate the Risk of Late Grade ≥3 Xerostomia in Patients Irradiated for Head-and-Neck Cancer.

Xerostomia is a serious complication following radiotherapy of head-and-neck cancers. A prognostic tool was developed for estimating its risk. In our previous study, age, tumor site, bilateral lymph node involvement, definitive radiotherapy, and addition of systemic therapies showed significant associations with grade ≥3 late xerostomia or trends. In additional analyses, mean radiation dose to ipsilateral parotid gland was significant (p=0.011). These six factors were included in the prognostic tool. Scoring points of 0 (lower risk) or 1 (higher risk) were assigned to each factor and added for each patient. Patient scores ranged between 0 and 6; Grade ≥3 xerostomia rates were 0%, 8%, 24%, 26%, 25%, 42%, and 100%, respectively. Three groups were designed (0-1, 2-4, and 5-6 points) with grade ≥3 xerostomia rates of 5%, 25%, and 50%, respectively (p<0.001). This new tool helps estimating the risk of radiation-induced grade ≥3 xerostomia. It can support physicians and other medical staff members during treatment planning.

The dosimetric and clinical advantages of the GTV-CTV-PTV margins reduction by 6 mm in head and neck squamous cell carcinoma: Significant acute and late toxicity reduction

PurposeWe aim to identify the dosimetric and clinical impact of reducing the total GTV-CTV-PTV margins in head-and-neck squamous cell carcinoma (HNSCC) treated with definitive (chemo)radiation. Materials and methodsThe acute and late toxicity and outcomes of 155 consecutive patients treated between February 2017 and March 2019 with GTV-CTV-PTV margins of 9 mm were compared to those of 155 consecutive patients treated with total margin of 15 mm margin, before April 2015. All patients were treated with VMAT with daily-image guidance using CBCT. ResultsReducing the GTV-CTV-PTV by 6 mm resulted in significant reduction of total irradiated volume (PTV-total) by a median of 28.1% and significant reduction of doses to all salivary glands (largest reduction ipsilateral parotid gland; median −9.6 Gy) and constrictor muscle (−6.1 Gy) with subsequent reduction of the incidence of overall acute grade 3 toxicity (47.7% for 9 mm and 66.5% for 15 mm groups, p = 0.001), grade 3 mucositis (18.1% vs. 35.5%, p < 0.001) and feeding tube-dependency at the end of treatment (24.5% vs. 40%, p = 0.005). The incidence of late grade ≥ 2 xerostomia and dysphagia were also significantly lower in the 9 mm group (31.7% vs. 58.6% p < 0.001, and 15.4% vs. 26.7%, p = 0.04). The 2-year rates of loco-regional control, disease-free and overall survival were 78.8% vs.75.8%, 70.9% vs. 64.4%, and 83.8% vs. 67.6%, (p > 0.05, all). ConclusionReduction of the total GTV-CTV-PTV margins from 15 to 9 mm in HNSCC significantly reduced the irradiated volumes and the dose to salivary glands and constrictor muscle with significant reduction of radiation-related toxicity. The loco-regional control rates of both groups were comparable.

The influence of radiation dose on taste impairment in a prospective observational study cohort of oropharyngeal cancer patients

Background To analyze the influence of radiation dose on late radiation-associated taste impairment in oropharyngeal cancer (OPC) patients treated with intensity-modulated radiotherapy (IMRT) using the taste bud bearing tongue mucosa as organ at risk. Material and methods This study is part of an ongoing, prospective observational study. Cancer-free OPC survivors with at least 24 months from IMRT were included in this analysis. Scores for taste impairment and dry mouth were extracted from the MD Anderson Symptom Inventory Head and Neck module (MDASI-HN) with scores of ≥5 considered as moderate-to-severe symptoms. The mean dose, minimum and maximum dose to the taste bud bearing tongue mucosa, the ipsi- and contralateral parotid and submandibular glands were extracted and analyzed for correlation with moderate-to-severe taste impairment. Results One hundred sixteen T1–4 OPC patients were included (81% males, median age: 55). The primary tumor was in the tonsil in 92 cases (79%) and in the base of tongue in 21 cases (18%). Patients were treated with 64.2–72.0 Gy; 37 patients (32%) received concurrent chemotherapy and 22 (19%) concurrent targeted therapy. After a median of 58 months from RT (IQR: 43–68) 38 patients (33%) suffered from moderate-to-severe long-term radiation-associated taste impairment. No dose volume parameter of the taste bud bearing tongue mucosa and the salivary glands was significantly associated with moderate-to-severe taste impairment for the whole patient cohort. For patients without concurrent chemotherapy, the minimum and mean dose to the ipsilateral parotid gland, and the maximum dose to the submandibular gland was significantly associated with late taste impairment (all p < 0.05). A significant correlation was found between taste impairment and dry mouth (p < 0.001). Conclusion The dose to the ipsilateral parotid gland seems to play an important role in the development of late taste impairment. The influence of dose to the taste bud bearing tongue mucosa remains unclear and needs further investigation.

Qualitative and dosimetric assessment of radiation-induced xerostomia in patients with oral cancers treated with 3DCRT versus IMRT: A prospective observational study

Background: Xerostomia is an important complication in patients with head-and-neck cancer treated with radiotherapy. It is caused by the radiation dose to the salivary glands situated in the lateral facial and submandibular regions, which are commonly included in or are close to the target volume.Objectives: Our primary objective was to evaluate xerostomia in patients treated with three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT). We also aimed to identify the risk factors for the development of xerostomia and the treatment-related and dosimetric parameters associated with xerostomia in patients with oral cancers receiving radiotherapy.Materials and Methods: We enrolled 100 patients with oral cancers between Sept 2015 and Apr 2018 who were planned for adjuvant radiotherapy. Patients were treated with unilateral portals in 3DCRT or IMRT. Xerostomia was assessed using the Wake Forest National Cancer Institute Community Oncology Research Program Research Base (WF NCORP RB) # 97115 Questionnaire at baseline, treatment completion, and at 1, 4, and 7 months following the completion of radiotherapy. Detailed salivary gland dosimetric parameters including the minimum (Dmin), maximum (Dmax), and mean dose (Dmean) and other dose and volume parameters (e.g., D25, D50, D75, and V10–V60) were assessed through cumulative dose volume histograms (DVH). Multivariate analysis was performed to determine the factors associated with the development of xerostomia and assess the correlation with dosimetric parameters.Results: At a median follow-up of 20 (95% confidence interval [CI], 8–32) months, the V20, V25, V30, V40, V45, V50, V60, Dmin, and Dmean received by the ipsilateral parotid gland were significantly lower in patients treated with IMRT compared to those treated with 3DCRT (P < 0.001). After the completion of radiotherapy, the mean xerostomia scores at each follow-up were significantly lower in the patients who had received IMRT, compared to 3DCRT. At 7 months of completion of treatment, the mean score of xerostomia in the 3DCRT arm was 44.4, compared to 33.8 in the IMRT arm (P = 0.023). On multivariate analysis, Dmin, V30, V40, V45, V60, history of substance abuse, advanced age, and lower body weight were found to be associated with higher chances of xerostomia.Conclusion: Compared to 3DCRT, IMRT results in lower rates of xerostomia based on dosimetric as well as subjective analysis.