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Publication Metadata only Pre-chemoradiotherapy low hemoglobin levels indicate increased osteoradionecrosis risk in locally advanced nasopharyngeal cancer patients(Springer Science and Business Media Deutschland GmbH, 2023) Yilmaz, Busra; Somay, Efsun; Topkan, Erkan; Pehlivan, Berrin; Selek, Uǧur; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, Turkey, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United StatesPurpose: We aimed to determine whether pretreatment hemoglobin (Hb) levels can predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (CCRT) for locally advanced nasopharyngeal carcinoma (LA-NPC). Methods: ORN cases were identified from the records of LA-NPCs who had oral exams before and after CCRT. All Hb measurements were obtained on the first day of treatment. Receiving operating characteristic curve analysis was used to determine the relationship between Hb levels and ORN rates. The relationship between pretreatment Hb levels and ORN rates served as the primary endpoint, and secondary endpoints included the discovery of additional potential ORN risk factors. Results: Among the 263 eligible LA-NPCs, we identified 8.7% ORN cases. The ideal cutoff Hb before CCRT was 10.6 g/dL. It was revealed that HPR ≤ 10.6 group had a significantly higher ORN rate (32.5% vs. 1.5% for Hb > 10.6, P < 0.001). The mandibular V59.8 ≥ 36% Gy, pre-CCRT ≥ 4 tooth extractions, the presence of post-CCRT tooth extractions, and the time of post-CCRT tooth extractions > 8 months were the other factors associated with significantly increased ORN rates (P < 0.05 for each). Conclusion: Low pre-CCRT Hb levels appeared to be independently linked to significantly higher ORN rates. Pretreatment Hb levels may be used to establish preventive measures and predict ORN. © 2023 Elsevier B.V., All rights reserved.Publication Metadata only The predictive usefulness of the novel combined hemoglobin-to-platelet ratio and maximum mouth opening index on prevalence of radiation induced trismus in patients with nasopharyngeal cancer(John Wiley and Sons Inc, 2023) Somay, Efsun; Yilmaz, Busra; Topkan, Erkan; Kucuk, Ahmet; Pehlivan, Berrin; Selek, Uǧur; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Kucuk, Ahmet, Department of Radiation Oncology, Mersin City Hospital, Mersin, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, Turkey, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United StatesObjectives: To explore how well a unique combination of hemoglobin-to-platelet ratio (HPR) and pretreatment maximum mouth opening (MMO) predicts the prevalence of radiation-induced trismus (RIT). Patients and methods: HPR and MMO cutoff values (0.54 and 40.7 mm) divided patients into two groups. To develop the novel HPR-MMO index, four combinations of these factors were tested for predictive power: Group 1: HPR > 0.54 and MMO > 40.7 mm, Group 2: HPR ≤ 0.54 but MMO > 40.7 mm, Group 3: HPR > 0.54 but MMO ≤ 40.7 mm, Group 4: HPR ≤ 0.54 and MMO ≤ 40.7 mm. Results: Data of 198 patients with LA-NPC was analyzed retrospectively. RIT rates for Groups 1 to 4 were 10.2%, 15.2%, 25%, and 59.4%. Groups 2 and 3 were merged to generate HPR-MMO index because of statistically equivalent RIT rates: Low-risk: HPR > 0.54 and MMO > 40.7 mm, Intermediate-risk: HPR ≤ 0.54 but MMO > 40.7 mm or, HPR > 0.54 but MMO ≤ 40.7 mm, High-risk: HPR ≤ 0.54 and MMO ≤ 40.7 mm. It was revealed that the low-, high-, and intermediate-risk group's RIT rates, 10.2%, 59.4%, and 19.2%, respectively. Conclusion: The novel HPR-MMO index may to classify LA-NPC patients into low, intermediate, and high-risk RIT groups. © 2023 Elsevier B.V., All rights reserved.Publication Metadata only Hemoglobin-to-platelet ratio in predicting the incidence of trismus after concurrent chemoradiotherapy(John Wiley and Sons Inc, 2023) Somay, Efsun; Yilmaz, Busra; Topkan, Erkan; Kucuk, Ahmet; Haksöyler, Veysel; Pehlivan, Berrin; Selek, Uǧur; Araz, Kenan; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Dentomaxillofacial Radiology, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Kucuk, Ahmet, Department of Radiation Oncology, Mersin City Hospital, Mersin, Turkey; Haksöyler, Veysel, Department of Medical Oncology, Medline Hospital, Adana, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, Turkey, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United States; Araz, Kenan, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, TurkeyObjective: The significance of pre-hemoglobin-to-platelet ratio (HPR) in predicting the occurrence of radiation-induced trismus (RIT) in locally advanced nasopharyngeal carcinoma patients (LA-NPC) who received concurrent chemoradiotherapy (C-CRT). Methods: The records of LA-NPC patients with oral examination before and after C-CRT were analyzed. Maximum mouth openings (MMO) were measured before and after C-CRT to confirm RIT status, with an MMO of ≤35 mm defined as RIT. HPR values were calculated on the first day of C-CRT. The relationship between the HPR values and RIT status was discovered using the receiver operating characteristic curve analysis. Results: A total of 43 patients RIT cases among 198 individuals were diagnosed. The optimal HPR cutoff that stratified the patients into two groups was 0.54. RIT incidence was found to be significantly higher in the HPR ≤0.54 group than its HPR >0.54 counterpart(p < 0.001). Univariately T3-4 stage, mean masticator apparatus dose>57.2Gy, and pre-C-CRT MMO ≤40.7 mm were found as the other significant correlates of increased RIT rates(p < 0.05). All four variables seemed to be independently connected to greater RIT incidence in multivariate analysis (p < 0.05, for each). Conclusion: The risk of post-C-CRT RIT may be significantly increased when pre-treatment HPR levels are low. © 2023 Elsevier B.V., All rights reserved.Publication Metadata only Initial neutrophil-to-lymphocyte ratio predicts radiation-induced trismus in parotid gland cancer(John Wiley and Sons Inc, 2023) Somay, Efsun; Yilmaz, Busra; Topkan, Erkan; Kucuk, Ahmet; Pehlivan, Berrin; Selek, Uǧur; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Kucuk, Ahmet, Department of Radiation Oncology, Mersin City Hospital, Mersin, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, Turkey, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United StatesObjective: To investigate the link between pretreatment neutrophil-to-lymphocyte ratio(NLR) and the incidence of radiation-induced trismus(RIT) in parotid gland cancers(PGC) patients after postoperative radiotherapy(PORT). Method: Data of PGC patients who had oral examinations before and after PORT were reviewed retrospectively. We comprised patients who had maximum mouth opening (MMO) assessments before and after PORT and complete blood count test on the first day of PORT. MMO of ≤35 mm was considered as RIT. The receiver operating characteristic (ROC) curve analysis was used to search for an ideal NLR threshold value that might be linked to RIT rates. Results: Fifty-one patients were included, with a RIT incidence of 15.7%. The NLR cutoff that showed a link with the prevalence of RIT in the ROC curve analysis was 2.7[Area under the curve (AUC):82.0%, sensitivity:87.5%, specificity:74.4%]. The patients were divided into groups based on this value:Group 1: NLR≤2.7 (N = 34) and,NLR >2.7 (N = 17). In comparative analysis, the incidence of RIT was found to be statistically higher in the NLR >2.7 than counterpart (35.2%vs.5.8%,rs:0.79, p <.001). Also, a mean temporomandibular joint dose ≥51.0Gy was linked to increased RIT rates (p <.001). Conclusion: This study showed that high pre-PORT NLR levels were a robust and independent predictor of significantly elevated rates of RIT. © 2023 Elsevier B.V., All rights reserved.Publication Metadata only Utility of pre-chemoradiotherapy Pan-Immune-Inflammation-Value for predicting the osteoradionecrosis rates in locally advanced nasopharyngeal cancers(Springer Science and Business Media Deutschland GmbH, 2023) Yilmaz, Busra; Somay, Efsun; Topkan, Erkan; Kucuk, Ahmet; Pehlivan, Berrin; Selek, Uǧur; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Kucuk, Ahmet, Department of Radiation Oncology, Mersin City Hospital, Mersin, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, TurkeyPurpose: The aim of this retrospective study was to explore whether pretreatment Pan-Immune-Inflammation-Value (PIV) measurements might predict the risk of mandibular osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (CCRT) for locally advanced nasopharyngeal cancer (LA-NPC). Methods: The platelet, monocyte, neutrophil, and lymphocyte counts acquired on the first day of CCRT were used to compute pretreatment PIV levels: PIV = (Platelets × Monocytes × Neutrophils) ÷ Lymphocytes. Receiver operating characteristic curve analysis was used to determine the association between ORN rates and PIV levels. Spearman correlation analysis was used to examine the probable intergroup correlations. The potential link between the pretreatment PIV levels and the post-treatment ORN rates was determined as the primary objective. Results: 21 (10.0%) of 210 eligible patients were diagnosed with ORN. The optimal pre-CCRT PIV cutoff was 833, which separated patients into two PIV groups with divergent ORN prevalence estimates: Group 1: PIV < 833 (N = 153), and Group 2: PIV ≥ 833 (N = 57). The comparison analysis found that the PIV ≥ 833 cohort had significantly higher ORN rates than the PIV < 833 cohort (29.8% vs. 2.6%, P < 0.001). Other characteristics linked to significantly higher ORN rates were the patient’s continuing smoking, the use of the Three-dimensional conformal radiation therapy technique, the mean mandibular dose of ≥ 58.1 Gy, the number of tooth extractions before CCRT ≥ 4, and the presence of tooth extractions after CCRT. The independent importance of all factors on higher ORN occurrence rates were retained in multivariate analysis (P < 0.05). Conclusions: Our findings revealed a strong link between aggravated inflammatory response and ORN genesis, with high pretreatment PIV levels related to significantly higher ORN rates. © 2023 Elsevier B.V., All rights reserved.Publication Open Access Pretreatment Masseter Muscle Volume Predicts Survival in Locally Advanced Nasopharyngeal Carcinoma Patients Treated with Concurrent Chemoradiotherapy(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Pehlivan, Umur Anil; Somay, Efsun; Yilmaz, Busra; Beşen, Ali Ayberk; Mertsoylu, Hüseyin; Selek, Uǧur; Topkan, Erkan; Pehlivan, Umur Anil, Department of Radiology, Başkent Üniversitesi, Ankara, Turkey; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Beşen, Ali Ayberk, Department of Medical Oncology, Medical Park Seyhan Hospital, Adana, Turkey; Mertsoylu, Hüseyin, Department of Medical Oncology, İstinye Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, TurkeyBackground and purpose: Muscle loss is a significant indicator of cancer cachexia and is associated with a poor prognosis in cancer patients. Given the absence of comparable studies, the current retrospective study sought to examine the correlation between the total masseter muscle volume (TMMV) before treatment and the survival outcomes in locally advanced nasopharyngeal cancer (LA-NPC) patients who received definitive concurrent chemoradiotherapy (CCRT). Methods: A three-dimensional segmentation model was used to determine the TMMV for each patient by analyzing pre-CCRT magnetic resonance imaging. The optimal TMMV cutoff values were searched using receiver operating characteristic (ROC) curve analyses. The primary and secondary endpoints were the relationship between the pre-CCRT TMMV measures and overall survival (OS) and progression-free survival (PFS), respectively. Results: Ninety-seven patients were included in this study. ROC curve analyses revealed 38.0 cc as the optimal TMMV cutoff: ≤38.00 cc (n = 42) and >38.0 cc (n = 55). Comparisons between the two groups showed that the TMMV>38.0 cc group had significantly longer PFS [Not reached (NR) vs. 28, p < 0.01] and OS (NR vs. 71, p < 0.01) times, respectively. The results of the multivariate analysis demonstrated that the T-stage, N-stage, number of concurrent chemotherapy cycles, and TMMV were independent associates of PFS (p < 0.05 for each) and OS (p < 0.05 for each) outcomes, respectively. Conclusion: The findings of the current retrospective research suggest that pretreatment TMMV is a promising indicator for predicting survival outcomes in LA-NPC patients receiving definitive CCRT. © 2024 Elsevier B.V., All rights reserved.Publication Open Access The predictive value of pretreatment hemoglobin-to-platelet ratio on osteoradionecrosis incidence rates of locally advanced nasopharyngeal cancer patients managed with concurrent chemoradiotherapy(BioMed Central Ltd, 2023) Yilmaz, Busra; Somay, Efsun; Topkan, Erkan; Kucuk, Ahmet; Pehlivan, Berrin; Selek, Uǧur; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Kucuk, Ahmet, Department of Radiation Oncology, Mersin City Hospital, Mersin, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, TurkeyBackground: This retrospective study aimed to investigate whether the pretreatment hemoglobin-to-platelet ratio (HPR) could predict the risk of osteoradionecrosis (ORN) in patients receiving concurrent chemoradiotherapy (C-CRT) for locally advanced nasopharyngeal carcinoma (LA-NPC). Methods: ORN cases were reported from the records of LA-NPC patients who had oral examinations before and after C-CRT. The pretreatment HPR values were calculated on the first day of C-CRT. The connection between HPR values and ORN occurrences was determined using receiver operating characteristic curve analysis. The primary endpoint was the relationship between the pretreatment HPR values and post-C-CRT ORN incidence rates, while secondary endpoints included the identification of other putative ORN risk factors. Results: We distinguished 10.9% incidences of ORN during the post-C-CRT follow-up period among 193 LA-NPC patients. The optimal cutoff for pre-C-CRT HPR was 0.48 that grouped the patients into two HPR groups with fundamentally different post-C-CRT ORN incidence rates: Group 1: HPR ≤ 0.48 (N = 60), and Group 2: HPR > 0.48 (N = 133). The comparative analysis indicated a significantly higher ORN incidence in HPR ≤ 0.48 group (30%, P < 0.001). The other factors associated with meaningfully increased ORN rates included the presence of pre-C-CRT ≥ 5 teeth extractions, mandibular volume receiving ≥ 64 Gy, post-C-CRT tooth extractions, mean mandibular dose ≥ 50.6 Gy, and C-CRT to tooth extraction interval > 5.5 months. Conclusion: Low pretreatment HPR levels were independently and unequivocally linked to significantly increased incidence of ORN post-C-CRT. Pre-C-CRT HPR levels may be used to estimate the incidence of ORN and be useful for taking preventive and therapeutic measures in these patients such as monitoring oral hygiene with strict follow-up, avoidance of unnecessary tooth extractions, particularly after C-CRT, and use of more rigorous mandibular RT dose limits. © 2023 Elsevier B.V., All rights reserved.Publication Open Access Valero’s host index is useful in predicting radiation-induced trismus and osteoradionecrosis of the jaw risks in locally advanced nasopharyngeal carcinoma patients(BioMed Central Ltd, 2023) Topkan, Erkan; Somay, Efsun; Yilmaz, Busra; Pehlivan, Berrin; Selek, Uǧur; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, TurkeyBackground: In the absence of previous research, we sought to assess the H-Index’s predictive significance for radiation-induced trismus (RIT) and osteoradionecrosis of the jaw (ORNJ) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) receiving concurrent chemoradiotherapy (C-CRT). Patients and methods: The research comprised 295 LA-NPC patients who had C-CRT and pre- and post-C-CRT oral exams between June 2010 and December 2021. The H-Index was calculated using neutrophils, monocytes, lymphocytes, hemoglobin, and albumin measurements obtained on the first day of C-CRT. Patients were divided into three and two H-index groups, respectively, based on previously established cutoff values (1.5 and 3.5) and the cutoff value determined by our receiver operating characteristic (ROC) curve analysis. The primary objective was the presence of any significant connections between pretreatment H-Index groups and post-C-CRT RIT and ORNJ rates. Results: RIT and ORNJ was diagnosed in 46 (15.6%) and 13 (7.8%) patients, respectively. The original H-Index grouping could only categorize RIT and ORNJ risks at a cutoff value of 3.5, with no significant differences in RIT and ORNJ rates between groups with H-Index 1.5 and 1.5 to 3.5 (P < 0.05 for each). The ideal H-Index cutoff for both RIT and ORNJ rates was found to be 5.5 in ROC curve analysis, which divided the entire research population into two groups: H-Index ≤ 5.5 (N = 195) and H-Index > 5.5 (N = 110). Intergroup comparisons revealed that patients in the H-Index > 5.5 group had significantly higher rates of either RIT (31.8% vs. 5.9%, P < 0.001) or ORNJ (17.3% vs. 2.2%, P < 0.001) than their H-Index ≤ 5.5 counterparts. The results of the multivariate analysis showed that H-Index > 5.5 was independently linked to significantly higher RIT (P < 0.001) and ORNJ (P < 0.001) rates. Conclusion: Pre-C-CRT H-Index > 5.5 is associated with significantly increased RIT and ORNJ rates in LA-NPC patients receiving definitive C-CRT. © 2023 Elsevier B.V., All rights reserved.Publication Open Access Predicting Teeth Extraction after Concurrent Chemoradiotherapy in Locally Advanced Nasopharyngeal Cancer Patients Using the Novel GLUCAR Index(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Somay, Efsun; Topkan, Erkan; Yilmaz, Busra; Beşen, Ali Ayberk; Mertsoylu, Hüseyin; Selek, Uǧur; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Beşen, Ali Ayberk, Department of Medical Oncology, Medical Park Hospital, Bursa, Turkey; Mertsoylu, Hüseyin, Department of Medical Oncology, İstinye Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, TurkeyTo evaluate the value of the newly created GLUCAR index in predicting tooth extraction rates after concurrent chemoradiotherapy (C-CRT) in locally advanced nasopharyngeal carcinomas (LA-NPCs). Methods: A total of 187 LA-NPC patients who received C-CRT were retrospectively analyzed. The GLUCAR index was defined as ′GLUCAR = (Fasting Glucose × CRP/Albumin Ratio) by utilizing measures of glucose, C-reactive protein (CRP), and albumin obtained on the first day of C-CRT. Results: The optimal GLUCAR cutoff was 31.8 (area under the curve: 78.1%, sensitivity: 70.5%, specificity: 70.7%, Youden: 0.412), dividing the study cohort into two groups: GLUCAR ˂ 1.8 (N = 78) and GLUCAR ≥ 31.8 (N = 109) groups. A comparison between the two groups found that the tooth extraction rate was significantly higher in the group with a GLUCAR ≥ 31.8 (84.4% vs. 47.4% for GLUCAR ˂ 31.8, odds ratio (OR):1.82, p < 0.001). In the univariate analysis, the mean mandibular dose ≥ 38.5 Gy group (76.5% vs. 54.9% for <38.5 Gy, OR: 1.45, p = 0.008), mandibular V55.2 Gy group ≥ 40.5% (80.3 vs. 63.5 for <40.5%, p = 0.004, OR, 1.30), and being diabetic (71.8% vs. 57.9% for nondiabetics, OR: 1.23, p = 0.007) appeared as the additional factors significantly associated with higher tooth extraction rates. All four characteristics remained independent predictors of higher tooth extraction rates after C-CRT in the multivariate analysis (p < 0.05 for each). Conclusions: The GLUCAR index, first introduced here, may serve as a robust new biomarker for predicting post-C-CRT tooth extraction rates and stratifying patients according to their tooth loss risk after treatment. © 2024 Elsevier B.V., All rights reserved.Publication Metadata only The Use of Pre-Chemoradiotherapy Total Masseter Muscle Volume as a Novel Predictor of Radiation-Induced Trismus in Locally Advanced Nasopharyngeal Carcinoma Patients(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Somay, Efsun; Topkan, Erkan; Pehlivan, Umur Anil; Yilmaz, Busra; Beşen, Ali Ayberk; Mertsoylu, Hüseyin; Pehlivan, Berrin; Selek, Uǧur; Somay, Efsun, Department of Oral and Maxillofacial Surgery, Başkent Üniversitesi, Ankara, Turkey, Department of Oral and Maxillofacial Surgery, University of Kyrenia, Kyrenia, Cyprus; Topkan, Erkan, Department of Radiation Oncology, Başkent Üniversitesi, Ankara, Turkey; Pehlivan, Umur Anil, Department of Radiology, Başkent Üniversitesi, Ankara, Turkey; Yilmaz, Busra, Department of Oral and Maxillofacial Surgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Beşen, Ali Ayberk, Department of Medical Oncology, Medical Park Hospital, Bursa, Turkey; Mertsoylu, Hüseyin, Department of Medical Oncology, İstinye Üniversitesi, Istanbul, Turkey; Pehlivan, Berrin, Department of Radiation Oncology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Selek, Uǧur, Department of Radiation Oncology, Koç Üniversitesi, Istanbul, TurkeyBackground: We sought to determine whether pretreatment total masseter muscle volume (TMMV) measures can predict radiation-induced trismus (RIT) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) receiving concurrent chemoradiotherapy (C-CRT). Methods: We retrospectively reviewed the medical records of LA-NPC patients who received C-CRT and had pretreatment maximum mouth openings (MMO) greater than 35 mm. MMO of 35 mm or less after C-CRT were considered RIT. We employed receiver operating characteristic (ROC) curve analysis to explore the correlation between pre-treatment TMMV readings and RIT status. Results: Out of the 112 eligible patients, 22.0% of them received a diagnosis of RIT after C-CRT. The optimal TMMV cutoff that was significantly linked to post-C-CRT RIT rates was determined to be 35.0 cc [area under the curve: 79.5%, sensitivity: 75.0%, and specificity: 78.6%, Youden index: 0.536] in the ROC curve analysis. The incidence of RIT was significantly higher in patients with TMMV ≤ 5.0 cc than in those with TMMV > 35.0 cc [51.2% vs. 8.7%, Odds ratio: 6.79, p < 0.001]. A multivariate logistic regression analysis revealed that pre-C-CRT MMO ≤ 41.6 mm (p = 0.001), mean masticatory apparatus dose V56.5 ≥ 34% group (p = 0.002), and TMMV ≤ 35 cc were the independent predictors of significantly elevated rates of RIT. Conclusion: The presence of a smaller pretreatment TMMV is a reliable and independent novel biological marker that can confidently predict higher RIT rates in LA-NPC patients who receive C-CRT. © 2024 Elsevier B.V., All rights reserved.