Lobe Tumors Research Articles

Outcomes and surgical tips in the management of accessory parotid lobe tumours

The tumours of the parotid accessory lobe may present with significant challenges to the clinicians due to their rarity, presenting with diagnostic difficulties as well as difficult decision-making in terms of surgical approach.We retrospectively analysed 8 cases of accessory parotid lobe tumours treated in our unit. The presenting symptom was a mass in all cases present in the peri-parotid region with duration ranging from 6 weeks to 2 years. All cases were investigated with ultrasound-guided fine needle aspiration cytology (FNAC). Various surgical approaches were adopted that included standard cervico-facial (n = 4), trans-oral (n = 3) and cervical (n = 1) incision approach. The rate of early post-operative facial nerve weakness was 37.5% (n = 3). There were no cases of tumour recurrence.Any lump not typical of a parotid lump but close to the parotid region should be treated with a high degree of suspicion to exclude an accessory lobe tumour. A full work up with US-guided FNAC is recommended prior to definitive treatment. Although a standard cervico-facial incision approach is recommended in most cases, other direct approaches may also be considered depending on the location of the tumour. We present our experience of these tumours providing practical tips on diagnosis and surgical management.

The connection between frontal lobe brain tumors and lower urinary tract symptoms - Series of 347 patients.

The present study aimed to provide an early insight into the effect of intra-axial frontal lobe tumors on the micturition center and its potential role in producing compression in and around the prefrontal cortex. A total of 149 symptomatic patients were selected for urodynamic testing. The study sample included all patients with intra-axial frontal lobe tumors treated at two locations: the University Medical Center Tuebingen (Germany), and Azad University of Medical Sciences (Iran) between 2017 and 2020. Lower urinary tract symptoms (LUTS) were recorded in patients with frontal lobe compression due to local tumor growth. The symptomatic patients had brain magnetic resonance (MRI) images taken to examine for possible lesions. The treated patients (149 patients with a median age of 55 years) were evaluated using computer urodynamic investigation and voiding diaries. The results of urodynamic testing of 149 symptomatic patients showed detrusor over-activity in 82 (55%) patients, dyssynergia of detrusor-sphincter in 67 (45%) patients, uninhibited sphincter relaxation in 40 (27%) patients, and low-compliance bladder in 21 (14%) patients. There was no significant correlation found between tumor size and urinary symptoms (p = 0.103, Spearman q = 0.826). Frontal intra-axial tumors compressing and infiltrating the prefrontal cortex influence the micturition center and produce lower urinary tract symptoms. The tumors of the right frontal lobe were directly associated with incontinence, which was completely disappeared in 70% of the patients within 2 years.

Giant deep lobe parotid tumor removal via total parotidectomy without mandibulotomy. A simple and safe technique

The transmandibular route is often combined with the transparotid-transcervical approach when extensive surgical field exposure is required, as in the case of deep parotid lobe tumors measuring over 4 cm in size. This procedure implies great morbidity and prolongs surgery time. Furthermore, in cases where additional lip division is performed, the aesthetic outcomes may be poorer. A description is made of the technique used for the removal of giant pleomorphic adenomas of the parapharyngeal space, without mandibulotomy. Key words:Parapharyngeal space tumor, pleomorphic adenoma, transcervical-transparotid approach, transmandibular approach.

An analysis of neurocognitive dysfunction in brain tumors.

Background:Neurocognitive dysfunction is an important issue in patients with frontal lobe lesions. These patients who may be in good neurological status may succumb to neurocognitive dysfunction, affecting their daily living and hampering the quality of life. This study aims to correlate pre- and post-operative neurocognitive dysfunction in patients with frontal lobe lesions.Materials and Methods:A prospective analysis of 50 patients of newly-diagnosed frontal lobe tumors of any grade deemed suitable for surgical resection was carried out. All patients underwent neurocognitive testing using frontal assessment battery (FAB), mini mental state examination, and verbal learning and memory test pre- and post-operatively.Results:In this study, 22 patients had right frontal lobe lesion, whereas in 24 patients, it was located in the left frontal lobe, and 4 patients had bilateral lesions. Only 12 patients were found to be in good FAB score preoperatively, and all of them had symptom duration of less than 3 months. 1-week postsurgery, 26 patients achieved a good score, which increased to 44 at 3rd month. Patients who had psychological dysfunction for more than 3 months had average-to-bad preoperative FAB scores, while at 3rd month postoperatively, only six patients were in average score and none in bad score.Conclusion:Frontal lobe lesion should be kept in mind in patients with neurocognitive dysfunction. FAB is a simple bedside test that should be included in routine neurological examination in daily neurosurgical practice to assess long-term functional outcome in patients with frontal lobe lesions.

Clinical and dosimetric predictors of radiation pneumonitis in early-stage lung cancer treated with Stereotactic Ablative radiotherapy (SABR) – An analysis of UK’s largest cohort of lung SABR patients

BackgroundStereotactic Ablative Radiotherapy (SABR) is the standard treatment for early-stage medically inoperable lung cancer. Predictors of radiation pneumonitis (RP) in patients treated with SABR are poorly defined. In this study, we investigate clinical and dosimetric parameters, which can predict symptomatic RP in early-stage lung cancer patients treated with SABR. Materials and methodsPatients treated with lung SABR between May 2009 and August 2018, in a single United Kingdom (UK) radiotherapy center were included. The patient's baseline characteristics, treatment details, and toxicity were retrieved from the electronic medical record. Dosimetric data was extracted from Xio and Monaco treatment planning systems. Patients were treated according to the UK SABR consortium guidelines. RP was graded retrospectively using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, based on available clinical and imaging information. Univariate and multivariate binary logistic regression was performed to determine predictive factors for grade ≥ 2 radiation pneumonitis, using Statistical Package for the Social Sciences (SPSS) statistics version 21 software. The goodness of fit was assessed using the Hosmer and Lemeshow test. The optimal diagnostic threshold was tested using the Receiver operating characteristics (ROC) curve. The chi-square test was carried out to test the different risk factors against the likelihood of developing grade ≥ 2 pneumonitis. ResultsA total of 1266 patients included in the analysis. The median age of patients was 75 years. Six hundred sixty-six patients (52.6%) were female. Median follow up was 56 months. Sixty-five percent of patients received 55 Gy in 5 fractions. Forty-three percent of patients had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 and 16.2% had PS of 3. The Median Charlson comorbidity index was 6 (range 2–11). Median Standardized Uptake Value (SUV) max of the tumor was 6.5. Four hundred two patients (31.8%) had confirmed histological diagnosis; other patients were treated based on a radiological diagnosis. The median tumor size was 20 mm (range 4 mm–63 mm).Median Planning Target Volume (PTV) was 30.3 cc. Median values of R100, R50, and D2cm were 1.1, 5.6, 32.8 Gy. The median value of mean lung dose, V20, and V12.5 were 3.9 Gy, 5 %and 9.3% respectively.Eighty-five (6.7%) patients developed symptomatic RP (grade ≥ 2) with only 5(0.4%) developing grade 3 RP. Five percent of patients developed rib fractures but only 28% of these were symptomatic.On univariate analysis lower lobe tumor location, larger tumor size, PTV, mean lung dose, lung V20Gy, and V12.5 Gy were significantly associated with grade ≥ 2 RP. On multivariate analysis, only mean lung dose was associated with grade ≥ 2 pneumonitis.ROC curve analysis showed optimal diagnostic threshold for tumour size, PTV, mean lung dose, V20 and V12.5; are 22.5 mm ((Area Under Curve (AUC)-0.565)), 27.15 cc (AUC-0.58), 3.7 Gy (AUC-0.633), 4.6% (AUC-0.597), 9.5% (AUC-0.616). The incidence of ≥grade 2 RP was significantly high for values higher than the ROC threshold. ConclusionSABR treatment resulted in a very low rate of grade 3 pneumonitis. Lower lobe tumor location, larger tumor size, PTV, mean lung dose, V20, and V12.5 were found to be significant predictors of symptomatic radiation pneumonitis.

HGG-29. A CASE OF CIRCUMSCRIBED HIGH-GRADE ASTROCYTOMA WITH ATRX AND CDKN2A/B ALTERNATIONS WHO WAS INITIALLY DIAGNOSED AS GLIOBLASTOMA AND HAS 20 YEARS SURVIVAL

Pediatric high-grade gliomas are rare and often hard to classify, which grow locally and show longer survival than diffuse high-grade gliomas in adults. We report a case of circumscribed high-grade astrocytoma who was initially diagnosed as glioblastoma and has 20 years survival. A 7-year-old girl suffered from epileptic seizure due to a left occipital lobe tumor. The tumor was resected in another hospital and diagnosed as glioblastoma. The tumor disappeared after extended local irradiation and chemotherapy using nimustine hydrochloride (ACNU) and cisplatin (CDDP). Eighteen years after initial onset, first recurrence was confirmed as the intra-tumoral hemorrhage. The tumor was resected and diagnosed as anaplastic oligoastrocytoma. After 6 courses of temozolomide (TMZ), the tumor disappeared. Twenty years after initial onset, the second local recurrence was confirmed. Although gamma knife and TMZ was performed, the tumor did not disappear. The tumor was surgically resected. Histopathology showed localized growth with some infiltration and mitosis but lacked pseudopallisading and microvascular proliferation. The tumor was diagnosed as circumscribed high-grade astrocytoma. Immunostaining revealed ATRX nuclear loss and CDKN2A / B homozygous deletion. After 10 courses of TMZ, the third local recurrence was confirmed. The tumor was completely removed and has not occurred recurrence more than 3 months after the last operation. Circumscribed high-grade glioma is expected to survive longer than invasive glioma. Pediatric gliomas should differ from adult gliomas in the genes of tumorigenesis. Care should be taken for its diagnosis and treatments. We also need a new classification based on histology and gene profile. HGG-30, ANALYSIS OF PEDIATRIC GLIOMAS IN OUR INSTITUTE Kaoru Tamura, Mai Fujioka, Masae Kuroha, Motoki Inaji, Yoji Tanaka, Tadashi Nariai, and Taketoshi Maehara; Tokyo Medical and Dental University, Tokyo, Japan. PURPOSE: Recent advances in genetic interrogation of pediatric glioma increase the importance of molecular diagnosis using surgical specimen. However, surgical resection may be avoided to preserve quality of life, especially in brain stem glioma cases. We retrospectively examined diagnosis and treatment of pediatric gliomas in our hospital. METHODS: This study includes 14 consecutive glioma patients under the age of 18 who underwent initial treatment at our hospital from 2000 to 2019. Histopathological diagnosis, clinical course and molecular status such as IDH, H3F3A and BRAF were analyzed. RESULTS: 5 patients (1 pilocytic astrocytoma (PA), 3 diffuse astrocytomas, 1 oligodendroglioma were treated only by surgical resection (group A). 7 patients (1 PA, 1 anaplastic oligodendroglioma, 2 diffuse midline gliomas and 3 glioblastomas (GBM)) received radiation and/or chemotherapy after surgical resection (group B). 2 diffuse intrinsic pontine gliomas (DIPG) received radiation and chemotherapy without surgical resection (Group C). No IDH mutation was observed in all pathological specimen obtained cases. BRAF alteration was observed in all PA cases. 1 case of GBM had BRAF V600Emutation and the other had H3K27M mutation. During a median of 7.7 years of follow-up, group A patients have no recurrence. Group B includes various diagnosis and prognosis. 2 group C patients diagnosed DIPG by MRI showed different clinical courses. CONCLUSION: Pediatric gliomas include diverse biological subgroups and show broad range of clinical behavior. Since pediatric glioma has a low incidence and a wide variety of genetic mutations, multicenter study is important to improve the treatment of pediatric glioma.

RARE-13. INFLAMMATORY MYOFIBROBLASTIC TUMOR MIMICKING DESMOPLASTIC INFANTILE GANGLIOGLIOMA (DIG) OF THE TEMPORAL LOBE

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm composed of fascicles of myofibroblastic spindle cells in a background of prominent inflammatory infiltrate. It is categorized as ‘intermediate, rarely metastasizing’ in the World Health Organization classification of tumors of soft tissue and bone. We present a novel case of concurrent brain and lung tumor with diagnosis of TFG-ROS1-rearranged IMT in a 14 year old female patient, in which targeted next-generation sequencing became a powerful tool for detection of genomic alterations in both lung and brain tumors. At age 9, the patient’s lung mass was incidentally found and investigated for various infectious diseases with negative result. At age 14, she presented with seizure and was noted to have a stable size lung mass and a left temporal lobe tumor. The left temporal lobe tumor showed a desmoplastic spindle cell neoplasm involving the meninges and cerebral cortex and Desmoplastic Infantile Ganglioglioma (DIG) was considered one of differentials. Subsequently, her right lung mass was resected and showed a similar spindle cell neoplasm with a background of dense fibrosis and chronic inflammation, consistent with Inflammatory Myofibroblastic Tumor. Molecular microdissection revealed that both tumors shares TFG-ROS1 fusion which is associated with (t(3;6) (q12;q22)), thus it is strongly suggestive that two tumors arose from the same origin. No predisposition syndrome was identified.

Lower lobe origin is related to unfavorable outcomes in patients with stage I-III lung cancer treated with radical chemoradiotherapy.

The influence of tumor location on survival was investigated in patients with lung cancer who received radical chemoradiotherapy. We examined the relationships between radiation site and survival outcome in patients with lung cancer. A total of 14,640 patients with lung cancer who received radical chemoradiotherapy for stage I-III disease were reviewed from Surveillance, Epidemiology, and End Results Program (SEER) datasets. We further retrospectively collected cases from a cohort of 148 eligible patients diagnosed between December 2013 and December 2019. Female sex, adenocarcinoma, and stage III disease were significantly correlated with right lung lobe tumor. Advanced age at diagnosis was associated with lower lung tumor origin. For the patients who received radical chemoradiotherapy, 1- and 3-year survival rates were 56.5% and 22.9%. Lower lobe origin was closely related to a shorter overall survival compared to non-right lower lobe tumors (p < 0.001). We also validated the difference in our cohort (p = 0.004). Our results suggest that lower lobe tumor increases mortality risk in patients with lung cancer treated with radical chemoradiotherapy.

Predictors of outcome in pleomorphic xanthoastrocytoma.

Pleomorphic xanthoastrocytomas (PXA) are circumscribed gliomas that typically have a favorable prognosis. Limited studies have revealed factors affecting survival outcomes in PXA. Here, we analyzed the largest PXA dataset in the literature and identify factors associated with outcomes. Using the Surveillance, Epidemiology, and End Results (SEER) 18 Registries database, we identified histologically confirmed PXA patients between 1994 and 2016. Overall survival (OS) was analyzed using Kaplan-Meier survival and multivariable Cox proportional hazard models. In total, 470 patients were diagnosed with PXA (males = 53%; median age = 23 years [14-39 years]), the majority were Caucasian (n = 367; 78%). The estimated mean OS was 193 months [95% CI: 179-206]. Multivariate analysis revealed that greater age at diagnosis (≥39 years) (3.78 [2.16-6.59], P < .0001), larger tumor size (≥30 mm) (1.97 [1.05-3.71], P = .034), and postoperative radiotherapy (RT) (2.20 [1.31-3.69], P = .003) were independent predictors of poor OS. Pediatric PXA patients had improved survival outcomes compared to their adult counterparts, in which chemotherapy (CT) was associated with worse OS. Meanwhile, in adults, females and patients with temporal lobe tumors had an improved survival; conversely, tumor size ≥30 mm and postoperative RT were associated with poor OS. In PXA, older age and larger tumor size at diagnosis are risk factors for poor OS, while pediatric patients have remarkably improved survival. Postoperative RT and CT appear to be ineffective treatment strategies while achieving GTR confer an improved survival in male patients and remains the cornerstone of treatment. These findings can help optimize PXA treatment while minimizing side effects. However, further studies of PXAs with molecular characterization are needed.

Clinical Utility of Qualitative Elastography Using Acoustic Radiation Force Impulse for Differentiating Benign from Malignant Salivary Gland Tumors

The goal of the work described here was to evaluate the utility of acoustic radiation force impulse (ARFI) imaging, a novel elastography technique, for differentiating benign from malignant salivary gland tumors. With the use of conventional strain elastography (SE) and ARFI imaging with a four-pattern scoring system, 185 tumors were examined (163 benign/22 malignant). When a score of ≥3 was used to define malignancy, the sensitivity, specificity and accuracy were higher for ARFI imaging (77.3%, 63.8% and 65.4%, respectively) than for conventional SE (54.5%, 56.4% and 56.2%, respectively). ARFI imaging findings revealed that most (92%) Warthin tumors, but only 24% of pleomorphic adenomas, were benign (score: 1 or 2). Attenuation of acoustic push pulses made it difficult to determine the stiffness of malignant tumors in the deep parotid lobes. Thus, ARFI imaging is a useful tool for screening Warthin tumors and exhibits high sensitivity for malignant tumors of salivary glands, other than deep parotid lobe tumors.

BIOM-03. INVASIVE HISTOPATHOLOGY DRIVES POOR OUTCOMES IN SURGICALLY RESECTED BRAIN METASTASES

Abstract BACKGROUND Surgery as a single modality for the treatment of brain metastases (BrM) results in local recurrence (LR) in 60% of patients. These failure rates are reduced by half with post-operative radiotherapy. The non-invasive nature of BrM has led to the assumption that local recurrence is caused by spillage of cancer cells into the surgical cavity at the time of surgery. We present evidence suggesting that invasion of metastatic cancer cells into the adjacent brain is present in the majority of BrM and is associated with LR, leptomeningeal metastasis (LM), and overall survival (OS). METHODS We assessed the histopathological growth pattern (HGP) of 164 surgically resected BrM. HGP was correlated with LR, LM and OS. Single-cell transcriptomics (scRNAseq) was performed on 15,615 cells from metastasis center (MC) and surrounding brain (SB) adjacent to the tumor. N=30 orthotopic patient-derived xenograft models (OPDX) were established from BrM. RESULTS 56/164 (34%) BrM specimens showed a minimally invasive (MI) HGP between the tumor and adjacent brain while 108/164 (66%) showed significant invasion of tumor lobules or single-cells into the brain (HI-HGP). HI-HGP was associated with LR, LM and shortened OS in BrM patients. scRNAseq identified abundant cancer cells in SB that overexpressed pathways and genes involved in cell survival and stress adaptation compared to matched cancer cells in MC. Validation of these targets with immunohistochemistry in patient and OPDX tissues revealed cold-inducible RNA binding protein (CIRBP) overexpression in HI-HGP patient and OPDX BrM. Modulation of CIRBP expression in OPDX and cell line models of HI-HGP BrM delayed BrM progression and extended OS. CONCLUSION HI-HGP is a poor prognostic indicator in patients with surgically resected BrM, establishing HGP as an important prognostic factor that should be considered by clinicians treating BrM patients. We identify CIRBP as a functional mediator of this process.

NCOG-07. FEATURES OF EPILEPTOGENIC BRAIN METASTASES AND THEIR TREATMENT

Abstract Patients with brain metastases (BM) may experience seizures at diagnosis or during their treatment. Seizures are associated with decreased overall survival (OS) and poorer quality of life. Therapeutic options may include surgical resection of epileptogenic BM. This study evaluated features of epileptogenic BM and whether surgical resection of these tumors improved seizure control and OS. A retrospective single-center review between 2006-2016 identified 1581 patients with BM. Data analyzed included demographics, primary cancer, systemic treatments, radiographic features of BM, BM treatment modalities, anti-epileptic drugs (AEDs), and seizure characteristics before and after intervention for BM. Chi-squared tests were used for categorical variables. Kaplan-Meier curves and Breslow values were used to assess OS following seizure. Of 1581 patients with BM, 136 (9%) experienced one or more seizures. Seizure was the presenting symptom of BM in 74 (54.4%) patients. Melanoma metastases were most epileptogenic, causing seizure in 38 of 216 (17.6%) patients (p&amp;lt; 0.001). Frontal lobe metastases were most common in patients with seizures (100, 73.5% p=0.033). After median follow-up of 23 months, 48 of 80 (60%) surgical patients were seizure free compared with 27 of 56 (48.2%) non-surgical patients. OS from first seizure was improved in surgical patients versus non-surgical patients (735±133 vs 447±74 days, p=0.043). Frontal lobe tumor resection (n=61) conferred improved survival compared with non-frontal lobe tumor resections (n=19) (698±323 vs 344±132 days, p=0.044). Variables such as demographics, number of BM, tumor histology, and dose of AED were not significantly different between surgical and non-surgical groups. Seizures due to BM cause significant morbidity and mortality. Frontal lobe location and melanoma histology increase seizure risk. Resection of BM was associated with improved seizure control and prolonged OS from the time of first seizure. Further studies should delineate the impact of surgery and determine if a specific constellation of variables warrants prophylactic AEDs.

真皮导管瘤一例

Dermal duct tumor arising from the intradermal portion of the eccrine duct is a variant of benign eccrine sweat duct tumor. The tumor is a rare, usually occurs on the head and neck or limbs and presents as a non-characteristic, usually asymptomatic, flesh-colored or erythematous, firm nodule or papule. Histologically, the tumor lobules are located principally in the dermis with or without connection to the epidermis, showed similar architectural features and identical cytologic features of eccrine poroma. We report a case of dermal duct tumor which developed on the left calf area in a 57-year-old male patient.

Capacity of proton beams in preserving normal liver tissue during proton beam therapy for hepatocellular carcinoma.

Unirradiated liver volume (ULV) preservation rate is an important factor associated with radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) undergoing proton beam therapy (PBT). The purpose of this study is to identify the predictors for ULV preservation and quantify the capacity of proton beams in normal liver sparing during PBT. We reviewed planning data of 92 patients with single intrahepatic HCC tumors undergoing PBT. The potential clinical and planning factors that may affect ULV preservation were involved in multiple linear regression for ULV preservation rate. The significant factors were determined to be predictors and their influences were quantified. The median ULV preservation rate was 62.08%. All the assessed clinical factors showed significant effects on ULV preservation rate: clinical target volume (CTV), P < 0.001; portal vein tumor thrombosis (PVTT), P = 0.010; left lobe tumor, P = 0.010. In contrast, none of the planning factors demonstrated significance. The coefficients of significant factors in multiple linear regression were 60.85 for intercept, −0.02 for CTV, −9.01 for PVTT and 8.31 for left lobe tumors. The capacity of proton beams to spare normal liver tissue during PBT for HCC is mainly affected by clinical factors. The baseline of the ULV preservation rate is 60.85%, decreasing 0.02% with each milliliter of CTV increase and 9.01% for tumors with PVTT, and increasing 8.31% for tumors limited to the left lobe. Further clinical studies should be carried out to correlate our dosimetric findings with clinical outcomes.

Does location matter? Characterisation of the anatomic locations, molecular profiles, and clinical features of gliomas.

Neuroanatomic locations of gliomas may influence clinical presentations, molecular profiles, and patients' prognoses. We investigated our institutional cancer registry to include patients with glioma over a 10-year period. Statistical tests were used to compare demographic, genetic, and clinical characteristics among patients with gliomas in different locations. Survival analysis methods were then used to assess associations between location and overall survival in the full cohort, as well as in relevant subgroups. 182 gliomas were identified. Of the tumours confined to a single lobe, there were 51 frontal (28.0%), 50 temporal (27.5%), 22 parietal (12.1%), and seven occipital tumours (3.8%) identified. Tumours affecting the temporal lobe were associated with reduced overall survival when compared to all other tumours (11 months vs. 13 months, log-rank p = 0.0068). In subgroup analyses, this result was significant for males [HR (95%CI) 2.05 (1.30, 3.24), p = 0.002], but not for females [HR (95%CI) 1.12 (0.65, 1.93), p = 0.691]. Out of 82 cases tested for IDH-1, 10 were mutated (5.5%). IDH-1 mutation was present in six frontal, two temporal, one thalamic, and one multifocal tumour. Out of 21 cases tested for 1p19q deletions, 12 were co-deleted, nine of which were frontal lobe tumours. MGMT methylation was assessed in 45 cases; 7/14 frontal tumours and 6/13 temporal tumours were methylated. Our results support the hypothesis that the anatomical locations of gliomas influence patients' clinical courses. Temporal lobe tumours were associated with poorer survival, though this association appeared to be driven by these patients' more aggressive tumour profiles and higher risk baseline demographics. Independently, female patients who had temporal lobe tumours fared better than males. Molecular analysis was limited by the low prevalence of genetic testing in the study sample, highlighting the importance of capturing this information for all gliomas. The specific neuroanatomic location of tumours in the brain is thought to be predictive of treatment options and overall prognosis. Despite evidence for the clinical significance of this information, there is relatively little information available regarding the incidence and prevalence of tumours in the different anatomical regions of the brain. This study has more fully characterised tumour prevalence in different regions of the brain. Additionally, we have analysed how this information may affect tumours' molecular characteristics, treatment options offered to patients, and patients' overall survival. This information will be informative both in the clinical setting and in directing future research.

Impact of Anatomic Tumor Location on Clinical Outcomes: A Long-Term Analysis of Early Stage Non-Small Cell Lung Cancer Treated with Stereotactic Body Radiation Therapy and Fiducial Tracking

Treatment of early stage non-small cell lung cancer (ES-NSCLC) broadly includes surgical resection and definitive radiotherapy. Although surgical resection remains the standard of care for operable patients, approximately 20% of patients are deemed inoperable. A substantial body of literature has established stereotactic body radiation therapy (SBRT) as the ideal definitive therapy for those patients ineligible for surgery. A variety of techniques exist for SBRT delivery in the thorax, each with their own accommodations for respiratory motion. Such motion is linked with the anatomical location of the tumor, with those closer to the diaphragm demonstrating larger excursions than those localized to the upper lobes. In this study, we examined the long-term outcomes of patients treated with robotic SBRT using fiducial tracking to elucidate variations in clinical outcomes as a consequence of tumor anatomical location. This is a single institutional analysis of patients with medically inoperable, biopsy-confirmed lymph-node negative (T1-3N0M0) ES-NSCLC using the AJCC 7th edition Cancer Staging Manual. Patients were treated per institutional protocol with robotic SBRT and fiducial tracking to a total dose of 45-60 Gy in 3 to 5 fractions prescribed to the planning target volume defined as a 5-mm expansion from the gross tumor volume. Estimates of overall survival, progression-free survival, local control, and locoregional control for patients were obtained using Kaplan-Meier analysis. Association with tumor stage, tumor location, histology, age, performance status, smoking history, and biologically equivalent dose were evaluated using Cox proportional hazards regression models. One-hundred medically inoperable patients with early stage NSCLC were treated from August 2005 to August 2017. The median age of all treated patients was 74 (range, 52 – 94). The majority of patients (n = 67) had tumors in the upper lobes. Most patients had T1a (n = 27), T1b (n = 27), or T2a (n = 25) tumors. After a median follow up of 3.3 years, median overall survival for the entire cohort was 50 months. At 3 years, overall survival rates were 62% for patients with upper lobe tumors and 54% for patients with lower lobe tumors (p = 0.10). Progression-free survival (62% v 54%, p = 0.38), local control (89% v 93%, p = 0.66), and locoregional control (83% v 79%, p = 0.98) rates were also similar between the two groups. Anatomical location did not appear to lead to significantly different long-term clinical outcomes. Fiducial tracking appears to work well in this diverse population of patients despite differences in respiratory motion. Future research should explore if difference in SBRT technique can lead to variations in clinical outcomes stratified by tumor anatomical location.

Adaptive Radiotherapy in Locally Advanced Lung Cancers – Real World Scenario from a Tertiary Cancer Center

Concurrent chemo-radiation (CTRT) for locally advanced lung cancer (LALC) leads to dynamic changes in tumor volume and location especially in patients with large tumor or atelectasis. Using adaptive radiotherapy (ART) prevents under dosage of the tumor and over dosage of the organs at risk (OAR). One hundred forty patients of LALC from Jan 2017 to Dec 2019 were treated with concurrent CTRT. A four-dimensional computed tomography (4D CT) scan was acquired and contouring of gross target volume (GTV) was guided by PET-scan fusion. All patients were planned to receive 60Gy/30 daily fractions with volumetric modulated arc therapy. Cone-beam CT (CBCT) for set-up verification was performed at least twice weekly. Change in anatomy and tumor response was determined on CBCT during weekly radiotherapy audit. Patients suitable for ART were re-simulated and re-planned. GTV now consisted of residual tumor and 5mm isotropic clinical target volume (CTV) was generated and manually extended to include areas suspicious for residual disease. Dose delivered prior to ART and time needed to execute ART (calculated from the day of re-simulation to the day of starting ART) were documented. The volumetric and dosimetric changes were analyzed using paired t-test between the 2 plans for full prescription dose. We also evaluated local control for this cohort. Out of 140 patients, 35 (25%) required re-planning for ART. Median age was 61 years (range 50 - 65). Twenty-six patients (75%) had upper lobe tumors. Fifteen (43%) patients had squamous carcinoma, 13 (37%) had adenocarcinoma, and 7 (20%) had small cell carcinoma. Requirement for ART was anticipated in 10/35 (28%) patients prior to CTRT. The triggers for ART were resolution of atelectasis in 7 (20%) patients, tumor response in 26 (74%) and progression in 2 (6%) patients. A median of 6 CBCTs prior to ART were acquired. A median of 26Gy (IQR 14-36Gy) was delivered prior to ART. While it required 5 days (IQR:3.5-7.5) for executing ART. There was a reduction in mean planning target volume of 23% (544cc - 418 cc; p = 0.003), mean GTV primary of 47% (153cc - 80.8cc; p = 0.024), and GTV nodes of 33.7% (8 cc - 5.3 cc; p = 0.033). The V20 of total lung minus PTV and the mean lung dose increased by 3.7% (18.8% - 19.5%; p = 0.158) and 4.5% (10.9Gy - 11.4Gy; p = 0.274) respectively whereas there was a reduction in heart V20 and Spinal cord Dmax by 18.3% (9.7 Gy to 8.2 Gy; p = 0.005) and 6.7% (36.6 Gy to 34.3 Gy; p = 0.100) respectively. At a median follow up of 14.7 months, the loco regional control rate was 70% and no patient experienced ³ grade 3 toxicity. In our practice approximately 25% patients of locally advanced lung cancer required ART, with tumor response and resolution of atelectasis being the most common triggers. Anticipation of clinically significant change, frequent use of on-board imaging and implementation of ART could prevent under dosage of the tumor and over dosage of OAR.

Functional outcomes after extracapsular dissection with partial facial nerve dissection for small and large parotid neoplasms.

Multiple surgical options exist for benign parotid tumors without agreement upon a single, best approach. We evaluated the short-term outcomes and rate of complications using the ECD-FND technique for small and large parotid neoplasms involving the superficial and deep lobes of the parotid gland using a categorical approach. A single surgeon retrospective cohort study with analysis of patient demographics, outcomes, and complication rates was conducted of patients undergoing the ECD-FND for benign parotid neoplasm. Cases from May 2014 to May 2020 with at least 6months follow up were considered. Complications were assessed by chart review and tumors were categorized by size and by European Salivary Gland Society (ESGS) classification assigned by a neuroradiologist. Fifty-one patients who underwent ECD-FND of suspected benign parotid mass met inclusion criteria. The most common histology was pleomorphic adenoma (56.9%) followed by Warthin's tumor (19.6%). Overall rate of complications was 31.4% with no major complications. Most patients (88.2%) had normal facial nerve function immediately after surgery and all recovered completely in the post operative period. Sialocele occurred in 15.7% of patients with 87.5% resolved within one month and seromas occurred in four patients (7.8%). There was no significant difference in complication rates between the size of tumor (p=0.889), depth (p=0.770), or ESGS classification (p=0.846). The ECD-FND technique achieved excellent facial nerve outcomes among our cohort, which included a - proportion of large (>3cm) and deep lobe tumors. Complications rates and outcomes were similar for larger and deep lobe tumors that underwent a ECD-FND approach. 3.

Effectiveness of intraoperative facial nerve monitoring and risk factors related to postoperative facial nerve paralysis in patients with benign parotid tumors: A 20-year study with 902 patients

ObjectiveWe examined the incidence, risk factors, and recovery time for postoperative facial nerve paralysis in patients with benign parotid tumors and also investigated the usefulness of intraoperative facial nerve monitoring (FNM). MethodsSubjects were 902 patients with benign parotid tumors. Univariate and multivariate analyses were conducted for risk factors of postoperative facial nerve paralysis. We investigated the relationship between intraoperative FNM and postoperative facial nerve paralysis, and the recovery time for postoperative facial nerve paralysis according to tumor site. ResultsPostoperative facial nerve paralysis occurred in 179 (19.8%) of 902 patients. Among them, 15.1%, 15.8%, and 37.5% had tumors in the superficial lobe, lower pole, and deep lobe, respectively. Paralysis risk factors were deep tumors, large tumors, long operation times, extensive bleeding, and non-use of FNM. Multivariate analysis determined female patients, deep tumors, and long operation times as significant risk factors, and female patients and deep tumors had an odds ratio of nearly 2. Use of intraoperative FNM resulted in a significantly lower incidence of facial nerve paralysis and was particularly useful in patients with superficial lobe tumors. Time to recovery from facial nerve paralysis was 6 months in 88% of the patients. ConclusionThe incidence of paralysis should be kept as low as possible to enhance the postoperative quality of life of patients. The use of intraoperative FNM significantly lowered the incidence of paralysis in female patients with superficial tumors.

Comparison of Parotidectomy With Observation for Treatment of Pleomorphic Adenoma in Adults

There is no consensus regarding optimal management of pleomorphic adenoma in adults. To compare parotidectomy with observation for the management of pleomorphic adenoma in patients 50 years or older by age. This decision analytical model was performed from November 21, 2019, to June 15, 2020, using a Markov model. Model variables and ranges were selected based on a literature review. A 1-way sensitivity analysis was performed to evaluate the age threshold at which each algorithm, either upfront elective parotidectomy or observation, would be favored. A Monte Carlo probabilistic sensitivity analysis using variable ranges was then performed 5 times with patients in the model assigned a starting age of 50, 60, 70, 80, and 90 years to assess how age at diagnosis would be associated with the model results. Model outcomes were measured with quality-adjusted life-years (QALYs). In the study models, the age thresholds at which observation became more beneficial than parotidectomy were 88.5 years for patients with superficial lobe tumors (5.37 QALYs in favor of parotidectomy below this age, and 5.37 QALYs in favor of observation above this age) and 83.4 years for patients with deep lobe tumors (7.51 QALYs in favor of surgery below this age, and 7.51 QALYs in favor of observation above this age). There was no significant difference in outcomes between parotidectomy and observation among patients aged 70 to 80 years. This study suggests that the outcomes associated with parotidectomy and observation are similar at 70 years or older among patients with pleomorphic adenoma and that observation may be the favorable treatment in that age group.