Central Neurocytoma Treated Using Supratentorial Ventricle Radiotherapy: A Single-Institution Analysis of Five Cases in Adjuvant or Salvage Settings After Surgery.

INTRODUCTION: Central neurocytoma (CN) is an extremely rare tumor primarily located in the supratentorial ventricular system, categorized as a glioneuronal or neuronal tumor. METHODS: This study presented a retrospective analysis of five CN patients who received adjuvant or salvage radiotherapy. Patients, aged 31-59 years, underwent radiation doses ranging from 60 Gy to 50.4 Gy over 27-30 fractions. RESULTS: All patients achieved effective local tumor control without severe complications. The median follow-up period was 51.7 months, demonstrating 100% overall and progression-free survival rates. DISCUSSION: Our study's clinical outcomes align with previous research, despite the limitation of a small sample size. Emphasizing the necessity for additional research, our findings added to the potential evidence of radiotherapy in managing CN. Larger, long-term studies were needed to confirm these promising results.

Risk factors for local recurrence of keloids and hypertrophic scars after postoperative electron beam radiotherapy.

OBJECTIVE: Keloids and hypertrophic scars are benign fibroproliferative lesions that occur as a result of skin injury. Postoperative radiation therapy is used to reduce the recurrence rate because of the high recurrence rate with surgical treatment alone. This study aimed to identify the risk factors for recurrence after postoperative electron beam radiotherapy. MATERIALS AND METHODS: Patients with keloid or hypertrophic scars with at least one lesion and who underwent postoperative electron beam radiotherapy at our institution from June 2013 to March 2022 were included in the study, while patients with a follow-up period of fewer than three months were excluded. RESULTS: A retrospective analysis was performed on 94 lesions in 81 patients. Exactly two years after the treatment, the actuarial local control rate was 86.4%. The chest wall, shoulder, and suprapubic area were identified as high-risk recurrence sites. Compared to other body sites, these sites had significantly lower local control rates (two-year local control rates: 75.5% vs. 95.2%, P = 0.005). After multivariate analysis, treatment site (P = 0.014), male gender (P = 0.019), and younger age (P = 0.029) were revealed to be statistically significant risk factors for local recurrence. Risk factors for keloid recurrence after postoperative electron beam radiotherapy were therefore identified. CONCLUSION: This result could be used for follow-up and as a determinant for the optimal dose/fractionation of postoperative radiotherapy.

Prognostic value of radiomic features in patients with esophageal cancer treated with chemoradiotherapy.

BACKGROUND: The aim of the present study was to evaluate the prognostic value of radiomic features in patients who underwent chemoradiotherapy for esophageal cancer. METHODS: In this retrospective study, two independent cohorts of esophageal cancer patients treated with chemoradiotherapy were included. Radiomics features of each patient were extracted from pre-treatment computed tomography (CT) images. Radiomic features were selected by employing univariate and multivariate analyses in the test cohort. Selected radiomic features were verified in the validation cohort. The endpoint of the present study was overall survival. RESULTS: A total of 101 esophageal cancer patients were included in our study, with 71 patients in the test cohort and 30 patients in the validation cohort. Univariate analysis identified 158 radiomic features as prognostic factors for overall survival in the test cohort. A multivariate analysis revealed that root mean squared and Low-High-High (LHH) median were prognostic factors for overall survival with a hazard ratio of 2.23 (95% confidence interval [CI]: 1.16-4.70, P = 0.017) and 0.26 (95% CI: 0.13-0.54, P < 0.001), respectively. In the validation cohort, root mean squared high/LHH median low group had the most preferable prognosis with a median overall survival of 73.30 months (95% CI: 32.13-NA), whereas root mean squared low/LHH median low group had the poorest prognosis with a median overall survival of 9.72 months (95% CI: 2.50-NA), with a P value of < 0.001. CONCLUSIONS: We identified two radiomic features that might be independent prognostic factors of overall survival of esophageal cancer patients treated with chemoradiotherapy.

Curative Radiotherapy for Oropharyngeal Squamous Cell Carcinoma Stratified by p16 Status, According to the Eighth Edition American Joint Committee on Cancer Staging Manual: A Retrospective Study.

Background/Aim: The prevalence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing worldwide. This retrospective study aimed to investigate the clinical outcomes of patients with OPSCC undergoing definitive radiotherapy, stratified according to their p16 status. Patients and Methods: A retrospective analysis was conducted on consecutive patients with OPSCC treated with curative external beam radiotherapy between May 2015 and September 2023. Clinical staging was determined by the eighth edition AJCC staging manual for p16 positive and negative OPSCC. All patients were treated with radiotherapy using a simultaneous integrated boost (SIB) with helical tomotherapy. The fractionation scheme, with or without chemotherapy, for the primary site and nodal lesions consisted of 2 Gy per fraction for a total dose of 70 Gy in 35 fractions over seven weeks. Results: This study included 76 patients with a median age of 66 years. With a median follow-up time of 32.6 months, the 3-year progression-free survival rate was significantly higher in p16 positive patients compared to p16 negative patients (79.6% vs. 42.5%, p<0.001). Concerning 54 patients with p16-positive tumors, the overall survival rates indicated excellent clinical outcomes for stage I, II, and III with results of 100%, 100%, and 88.1%, respectively. Conclusion: This retrospective study revealed the clinical outcomes of patients with OPSCC treated with radical radiotherapy, emphasizing the significance of p16 status. While acknowledging the limitations of the retrospective nature of this study, future prospective studies with larger cohorts and extended follow-up periods are needed to enhance evidence quality.

Safety evaluation of sinus patency after stereotactic radiosurgery for transverse-sigmoid sinus dural arteriovenous fistulas: implications of treatment options for patients with Borden type I fistulas.

OBJECTIVE: This study aimed to assess the efficacy and safety of stereotactic radiosurgery (SRS) in treating transverse-sigmoid sinus dural arteriovenous fistulas (TSS DAVFs), and to investigate post-SRS sinus patency, focusing on the risk factors associated with treated sinus occlusion. METHODS: Data from 34 patients treated with SRS between January 2006 and April 2023 were analyzed. Detailed angioarchitecture was confirmed using digital subtraction angiography before SRS. Angiography of the ipsilateral internal carotid artery and vertebral artery was performed to evaluate whether the involved side of the TSS was used for normal venous drainage. TSS stenosis was defined as sinus diameter < 50% of the normal proximal diameter. DAVF shunt obliteration, TSS occlusion, neurological status, and adverse events were also evaluated. RESULTS: Of the 34 patients, 21 had Borden type I and 14 had Borden type II DAVFs. The median age at SRS was 64 years (interquartile range 54-71 years), and the follow-up period was 31 months (interquartile range 15-94 months). Complete shunt obliteration was achieved in 24 (70.6%) patients. The cumulative 2-, 3-, and 5-year shunt obliteration rates were 49.6%, 71.2%, and 86.0%, respectively. Borden type I had higher obliteration rates (60.5%, 83.1%, and 94.4%, respectively) than Borden type II (41.7%, 51.4%, and 75.7%, respectively; p = 0.034). TSS occlusion occurred in 5 patients (14.7%). The cumulative 1-, 5-, and 10-year TSS occlusion rates were 2.9%, 8.3%, and 23.6%, respectively, across the entire cohort. All occlusions occurred exclusively in the sinuses that were not used for normal venous drainage. Cox proportional analyses revealed that TSS stenosis and the sinus not being used for normal venous drainage were significantly associated with a greater risk of TSS occlusion after SRS (HR 9.44, 95% CI 1.01-77.13; p = 0.049). CONCLUSIONS: SRS is effective and safe for TSS DAVF and results in favorable shunt obliteration, symptom improvement, and low complication rates. TSS occlusion after SRS is asymptomatic and is limited to sinuses that are not used for normal venous drainage.

Role of stereotactic radiosurgery for recurrent skull base acinic cell carcinoma: illustrative case.

BACKGROUND: Acinic cell carcinomas (AcCCs), rare malignancies of the salivary glands, often recur and metastasize, particularly in the skull base. Conventional radical resection can be invasive for skull base AcCCs adjacent to cranial nerves and major vasculature, and the effectiveness of stereotactic radiosurgery (SRS) as an alternative is not well established. OBSERVATIONS: This case report details the application of SRS for recurrent skull base AcCCs. A 71-year-old male with a history of resection for a right mandibular AcCC 23 years earlier experienced tumor recurrence involving the right cavernous sinus and nasal cavity. He underwent endoscopic transnasal surgery followed by SRS targeting different tumor locations-the cavernous sinus to the pterygopalatine fossa, maxillary sinus, and clivus-each with a prescribed dose of 20 Gy to the 40% to 50% isodose line. After the first skull base metastasis, additional sessions of localized SRS after endoscopic surgery led to a 12-year survival without sequela. LESSONS: This is a report indicating that SRS for skull base AcCCs can achieve favorable local control, functional preservation, and long-term survival. SRS may be suitable for skull base AcCC given the lesion's tendency toward multiple local recurrences. Further investigation is needed to validate the treatment's efficacy.

Long-term geometric quality assurance of radiation focal point and cone-beam computed tomography for Gamma Knife radiosurgery system.

To investigate the geometric accuracy of the radiation focal point (RFP) and cone-beam computed tomography (CBCT) over long-term periods for the ICON Leksell Gamma Knife radiosurgery system. This phantom study utilized the ICON quality assurance tool plus, and the phantom was manually set on the patient position system before the implementation of treatment for patients. The deviation of the RFP position from the unit center point (UCP) and the positions of the four ball bearings (BBs) in the CBCT from the reference position were automatically analyzed. During 544 days, a total of 269 analyses were performed on different days. The mean ± standard deviation (SD) of the deviation between measured RFP and UCP was 0.01 ± 0.03, 0.01 ± 0.03, and -0.01 ± 0.01 mm in the X, Y, and Z directions, respectively. The deviations with offset values after the cobalt-60 source replacement (0.00 ± 0.03, -0.01 ± 0.01, and -0.01 ± 0.01 mm in the X, Y, and Z directions, respectively) were significantly (p = 0.001) smaller than those before the replacement (0.02 ± 0.03, 0.02 ± 0.01, and -0.02 ± 0.01 mm in the X, Y, and Z directions, respectively). The overall mean ± SD of four BBs was -0.03 ± 0.03, -0.01 ± 0.05, and 0.01 ± 0.03 mm in the X, Y, and Z directions, respectively. Geometric positional accuracy was ensured to be within 0.1 mm on most days over a long-term period of more than 500 days.

Ki-67 labeling index predicts tumor progression patterns and survival in patients with atypical meningiomas following stereotactic radiosurgery.

PURPOSE: This study investigated whether Ki-67 labeling index (LI) correlated with clinical outcomes after SRS for atypical meningiomas. METHODS: This retrospective study examined 39 patients with atypical meningiomas who underwent SRS over a 10-year study period. Ki-67 LI was categorized into 3 groups: low (< 5%), intermediate (5%-10%), and high (> 10%). Local tumor control rates (LCRs), progression-free rates (PFRs), disease-specific survival (DSS) rates, and adverse radiation-induced events (AREs) were evaluated. RESULTS: The median follow-up periods were 26 months. SRS was performed at a median prescription dose of 18 Gy for tumors with a median Ki-67 LI of 9.6%. The 3-year LCRs were 100%, 74%, and 25% in the low, intermediate, and high LI groups, respectively (p = 0.011). The 3-year PFRs were 100%, 40%, and 0% in the low, intermediate, and high LI groups (p = 0.003). The 5-year DSS rates were 100%, 89%, and 50% in the low, intermediate, and high LI groups (p = 0.019). Multivariable Cox proportional hazard analysis showed a significant correlation of high LI with lower LCR (hazard ratio [HR], 3.92; 95% confidence interval [CI] 1.18-13.04, p = 0.026), lower PFR (HR 3.80; 95% CI 1.46-9.88, p = 0.006), and shorter DSS (HR 6.55; 95% CI 1.19-35.95, p = 0.031) compared with intermediate LI. The ARE rates were minimal (8%) in the entire group. CONCLUSION: Patients with high Ki-67 LI showed significantly more tumor progression and tumor-related death. Ki-67 LI might offer valuable predictive insights for the post-SRS management of atypical meningiomas.

Initial validation of a diaphragm tracking system for multiple breath-hold volumetric modulated arc therapy of abdominal tumors: A phantom study.

BACKGROUND: The breath-hold radiotherapy has been increasingly used to mitigate interfractional and intrafractional breathing impact on treatment planning and beam delivery. Previous techniques include body surface measurements or radiopaque metal markers, each having known disadvantages. PURPOSE: We recently proposed a new markerless technique without the disadvantages, where diaphragm was registered between DRR and fluoroscopic x-ray projection images every 180 ms during VMAT delivery. An initial validation of the proposed diaphragm tracking system (DiaTrak) was performed using a chest phantom to evaluate its characteristics. METHODS: Diaphragm registration was performed between DRR and projection streaming kV x-ray images of a chest phantom during VMAT delivery. Streaming data including the projection images and the beam angles were transferred from a linac system to an external PC, where the diaphragm registration accuracy and beam-off latency were measured based on image cross correlation between the DRR and the projection images every 180 ms. RESULTS: It was shown that the average of the beam-off latency was 249.5 ms and the average of the diaphragm registration error was 0.84 mm CONCLUSIONS: Initial validation of the proposed DiaTrak system for multiple breath-hold VMAT of abdominal tumors has been successfully completed with a chest phantom. The resulting beam-off latency and the diaphragm registration error were regarded clinically acceptable.

Histopathological, Demographic, and Clinical Signatures of Medulla Oblongata Germ Cell Tumors: A Case Report With the Review of Literature.

The medulla oblongata is one of the rarest sites of occurrence for germ cell tumors (GCTs) of the central nervous system. As there is scant data regarding epidemiology, clinical presentations, optimal intervention, and long-term prognosis, we aimed to delineate the features of this rare entity by presenting our representative case and performing a quantitative review of the literature. A 24-year-old woman presented to our department with vertigo and swallowing difficulties. Magnetic resonance imaging revealed a homogenously enhanced exophytic lesion arising from the medulla oblongata and extending to the fourth ventricle. Surgical resection was performed and a histological diagnosis of pure germinoma was made. The patient underwent chemotherapy and whole-ventricular irradiation. No recurrence has been experienced for 4 months after the surgery. According to the literature, the prognosis of GCTs at the medulla oblongata seems no worse than those at typical sites. Striking features including occurrence at an older age, female preponderance, and a predominance of germinoma were noteworthy. The pattern of local recurrence suggests extensive radiation coverage is not a prerequisite. Special attention is needed for cardiac and respiratory functions as the main factors eliciting mortality.

Relationship between hydrogel spacer distribution and dosimetric parameters in linear-accelerator-based stereotactic body radiotherapy for prostate cancer.

PURPOSE: To explore the potential of quantitative parameters of the hydrogel spacer distribution as predictors for separating the rectum from the planning target volume (PTV) in linear-accelerator-based stereotactic body radiotherapy (SBRT) for prostate cancer. METHODS: Fifty-five patients underwent insertion of a hydrogel spacer and were divided into groups 1 and 2 of the PTV separated from and overlapping with the rectum, respectively. Prescribed doses of 36.25-45 Gy in five fractions were delivered to the PTV. The spacer cover ratio (SCR) and hydrogel-implant quality score (HIQS) were calculated. RESULTS: Dosimetric and quantitative parameters of the hydrogel spacer distribution were compared between the two groups. For PTV, D99% in group 1 (n = 29) was significantly higher than that in group 2 (n = 26), and Dmax , D0.03cc , D1cc , and D10% for the rectum were significantly lower in group 1 than in group 2. The SCR for prostate (89.5 ± 12.2%) in group 1 was significantly higher (p < 0.05) than that in group 2 (74.7 ± 10.3%). In contrast, the HIQS values did not show a significant difference between the groups. An area under the curve of 0.822 (95% confidence interval, 0.708-0.936) for the SCR was obtained with a cutoff of 93.6%, sensitivity of 62.1%, and specificity of 100%. CONCLUSIONS: The SCR seems promising to predict the separation of the rectum from the PTV in linear-accelerator-based SBRT for prostate cancer.

Hypofractionated Radiotherapy as a Standalone Treatment Modality for Locally Advanced Type B2 Thymoma in an Octogenarian Patient: 45 Gy in 15 Fractions.

Thymic epithelial tumors (TETs), particularly type B2 thymomas, are rare neoplasms primarily found in the anterior mediastinum. The current therapeutic approach includes surgery, chemotherapy, and radiotherapy, but there is limited research on radiotherapy as a standalone treatment. This case report aims to elucidate the clinical outcomes of hypofractionated radiotherapy as a standalone treatment for locally advanced type B2 thymoma, offering insights into its potential efficacy and role in clinical practice.

Complete remission of perineal extra-mammary Paget's disease by curative-intent radiotherapy using volumetric modulated arc therapy in a patient older than 90 years.

ABSTRACT: Localized extra-mammary Paget's disease (EMPD) is mainly treated with surgical resection. Curative radiation therapy (CRT) is an alternative to surgery. Electron beams and conventional X-ray methods have been used in patients with EMPD for radiotherapy. The present report describes the case of a very elderly patient with perineal EMPD who was treated with definitive radiotherapy consisting of 60 Gy in 30 fractions. Surgery was deemed too difficult because of his age and comorbidities. We adopted volumetric modulated arc therapy as the radiotherapy modality, a recent, advanced form of intensity-modulated radiation therapy. Grade 3 dermatitis was observed as an acute phase adverse event, and he achieved a complete response and maintained remission for over one-year post-treatment. Our radiotherapy treatment protocol resulted in good clinical outcomes; therefore, it may be a candidate for inoperable patients with EMPD.

Survival Following Palliative Radiotherapy for Head and Neck Squamous Cell Carcinoma: Examining Treatment Indications in Elderly Patients.

Background/Aim: This study investigated the survival outcomes of patients with head and neck squamous cell carcinoma (HNSCC) undergoing palliative radiotherapy, particularly focusing on challenges and factors associated with older age, providing insights into appropriate palliative radiotherapy use in this demographic. Patients and Methods: A retrospective study was conducted using electronic medical records of 73 patients with HNSCC who were deemed unsuitable for curative therapy. Palliative radiotherapy involved a uniform dose of 30 Gy in 10 fractions. Survival analysis was performed using Kaplan-Meier method, and multivariate analysis identified significant prognostic factors. Results: The median overall survival was 7.5 months, with no significant difference between age groups. Karnofsky performance status (KPS) >70 correlated with favorable survival. Multivariate analysis confirmed KPS as an independent prognostic factor (hazard ratio=1.949, p=0.031). Conclusion: The results of this study align with those of previous studies, emphasizing the importance of palliative radiotherapy for HNSCC treatment. Optimal dose fractionation regimens remain undetermined, and tailored approaches that consider factors, such as age and performance status are crucial. Individualized, comprehensive assessments and supportive care measures enhance patient well-being, reflecting palliative care principles.

Clinical Outcomes of Curative Intent Radiotherapy by Helical Tomotherapy for Laryngeal Squamous Cell Carcinoma: A Retrospective Analysis in a Tertiary Referral Center.

Background: The management of laryngeal cancer involves balancing curative treatment with preserving essential functions. This study aimed to evaluate the clinical outcomes of helical tomotherapy, an advanced form of radiation therapy, as a primary treatment modality for laryngeal squamous cell carcinoma (LSCC). Methods: A retrospective analysis of data obtained from a tertiary referral center was performed to assess treatment response rates, survival outcomes, disease control, and treatment-related adverse events. Results: The study included 45 patients with LSCC treated with helical tomotherapy between May 2015 and September 2022. The 5-year overall survival (OS) rate and disease-free survival (DFS) rate were 89.2% and 71.1%, respectively. Local control and laryngeal preservation rates at 5 years were 79.7% and 84.7%, respectively. Subgroup analysis revealed higher DFS rates in early-stage patients (84.2%) compared to advanced-stage patients (58.9%). Conclusions: The results indicate that helical tomotherapy offers effective tumor control and potential for laryngeal preservation in LSCC. Further prospective studies and longer follow-up are needed to validate these findings and optimize treatment strategies for LSCC patients.

Radiotherapy in nonagenarian patients: A 20-year retrospective analysis in a single ternary centre.

INTRODUCTION: The global burden of cancer and the ageing population is increasing, resulting in an increase in cancer incidence among elderly patients. This study aimed to evaluate the clinical outcomes and safety profile of radiotherapy in nonagenarians and to contribute to the existing knowledge on radiotherapy in elderly patients. METHODS: This retrospective analysis included nonagenarian patients who received external beam radiotherapy at a single centre in Japan between May 2003 and May 2023. Data, including patient demographics, tumour characteristics, treatment details, and clinical outcomes, were collected from medical records. Statistical analyses including survival and subgroup analyses were performed to summarize the data. RESULTS: The analysis included 124 nonagenarian patients who received 151 treatment courses. Among the patients with a median age of 92 years (range, 90-98 years), 71 received palliative-intent radiotherapy and 53 underwent curative-intent radiotherapy. The overall survival rates at 1 and 3 years after radiotherapy were 55.4% and 38.3%, respectively. Performance status and radiotherapy at the primary site were independent prognosis factors for improved overall survival, while age was not. The incidence rate of grades 3-5 radiation-related toxicities was 3.4%, which is generally considered to be acceptable. CONCLUSION: This study demonstrates that radiotherapy can be effectively and safely used in this age group, supporting its use as a treatment option for both palliative and curative goals. These results contribute to the existing body of evidence on radiotherapy in elderly patients and can guide clinical decision-making in the management of nonagenarian patients with cancer.

Long-term outcomes of stereotactic radiosurgery for intracranial schwannoma in neurofibromatosis type 2: a genetic analysis perspective.

PURPOSE: Neurofibromatosis type 2 (NF2) is intractable because of multiple tumors involving the nervous system and is clinically diverse and genotype-dependent. Stereotactic radiosurgery (SRS) for NF2-associated schwannomas remains controversial. We aimed to investigate the association between radiosurgical outcomes and mutation types in NF2-associated schwannomas. METHODS: This single-institute retrospective study included consecutive NF2 patients with intracranial schwannomas treated with SRS. The patients' types of germline mutations ("Truncating," "Large deletion," "Splice site," "Missense," and "Mosaic") and Halliday's genetic severity scores were examined, and the associations with progression-free rate (PFR) and overall survival (OS) were analyzed. RESULTS: The study enrolled 14 patients with NF2 with 22 associated intracranial schwannomas (median follow-up, 102 months).　The PFRs in the entire cohort were 95% at 5 years and 90% at 10-20 years. The PFRs tended to be worse in patients with truncating mutation exons 2-13 than in those with other mutation types (91% at 5 years and 82% at 10-20 years vs. 100% at 10-20 years, P = 0.140). The OSs were 89% for patients aged 40 years and 74% for those aged 60 years in the entire cohort and significantly lower in genetic severity group 3 than in the other groups (100% vs. 50% for those aged 35 years; P = 0.016). CONCLUSION: SRS achieved excellent PFR for NF2-associated intracranial schwannomas in the mild (group 2A) and moderate (group 2B) groups. SRS necessitates careful consideration for the severe group (group 3), especially in cases with NF2 truncating mutation exons 2-13.

Intrafractional Diaphragm Variations During Breath-Hold Stereotactic Body Radiotherapy for a Liver Tumor Based on Real-Time Registration Between Kilovoltage Projection Streaming and Digitally Reconstructed Radiograph Images: A Case Report.

In liver stereotactic body radiotherapy (SBRT), precise image guidance is paramount, serving as the foundation of this treatment approach. The accuracy of SBRT in liver cancer treatment heavily relies on meticulous imaging techniques. The diaphragm, situated adjacent to the liver, is a crucial anatomical structure susceptible to positional and motion variations, which can potentially impact the accuracy of liver tumor targeting. This study explores the application of real-time kilovoltage projection streaming images (KVPSI) in comparison to digitally reconstructed radiography (DRR) for assessing diaphragm position deviations during breath-hold liver tumor SBRT. A 76-year-old male diagnosed with cholangiocarcinoma underwent breath-hold SBRT using split arc volumetric modulated arc therapy (VMAT), where a full arc was split into six sub-arcs, each spanning 60 degrees. The diaphragm dome positions were continuously monitored through KVPSI during treatment. The intrafractional position deviations of the diaphragm were calculated and analyzed for each split arc. The case report revealed a mean diaphragm dome deviation of 0.47 mm (standard deviation: 4.47 mm) in the entire arc. This pioneering study showcases the feasibility of intrafractional diaphragm position variation assessment using real-time KVPSI during the breath-hold liver tumor VMAT-SBRT. Integrating real-time imaging techniques enhances our comprehension of the intra-breath-hold variations, thereby guiding adaptive treatment strategies and potentially improving treatment outcomes. Clinical validation through further research is essential.

Failure Patterns of Recurrence in Patients With Localized Esthesioneuroblastoma Following Surgery and Adjuvant Radiotherapy Without Elective Nodal Irradiation.

BACKGROUND: Esthesioneuroblastoma (ENB), a rare malignancy arising from the olfactory epithelium, poses clinical challenges owing to its propensity for local invasion and recurrence. Its management typically involves surgical resection and adjuvant radiotherapy. However, debate persists regarding the optimal treatment strategy, particularly the use of elective nodal irradiation (ENI). This study aimed to investigate recurrence patterns in patients with localized ENB treated with surgery and adjuvant radiotherapy without ENI. METHODS: Our retrospective analysis included patients who underwent surgery followed by adjuvant radiotherapy for treatment of ENB between January 2011 and November 2022. Patients with incomplete data or who had received neoadjuvant radiotherapy were excluded. Patient characteristics, radiotherapy data (type, dose, and duration), and follow-up data were collected. Recurrence patterns were evaluated, and overall survival (OS), disease-free survival (DFS), and local control rates were determined using the Kaplan-Meier method. RESULTS: Twelve patients with ENB (median age, 56 years) were included. Most had stage C disease. The median radiation dose was 60 Gy, and the median treatment duration was six weeks. Only one death was confirmed during the observation period, and the five-year DFS rates were 64.3%. Local control was achieved in 11 patients, with only one experiencing local recurrence. Regional lymph node recurrence occurred in three patients and was successfully managed via neck dissection. The timing of recurrence varied, emphasizing the importance of long-term surveillance. CONCLUSION: Adjuvant radiotherapy without ENI is a viable treatment option for ENB, resulting in favorable local control and OS outcomes. Regional lymph node metastases were observed but effectively managed via salvage therapy. Prospective studies with larger cohorts are warranted to confirm the effectiveness of this treatment strategy and to define optimal radiotherapy fields.