Malignant salivary gland tumors of the tongue: A multicenter REFCOR study.

Salivary carcinomas of minor salivary glands are very infrequent tumors. When located in the tongue, the therapeutic strategy may comprise upfront surgery, which may be debilitating, and/or (chemo-)radiotherapy. The aim of this study was to identify the prognostic factors of salivary carcinomas of the tongue in a population-based cohort. This retrospective multicentric study, based on the "Réseau d'Expertise Français sur les Cancers ORL Rares" (REFCOR), included all the patients with a salivary carcinoma of the tongue, diagnosed between January 2009 and December 2018. Dubious slides were reviewed by REFCOR expert pathologists to ensure diagnostic accuracy. Treatment was performed in accordance with national REFCOR recommendations. From 28 centers, 103 patients were included in this study. Median age at diagnosis was 63 years, and 60.2% were female. Tumors were adenoid cystic carcinomas (41.7%), mucoepidermoid carcinomas (30.1%), and other adenocarcinomas (28.2%). Primary treatment was surgical for 61.2% of them. Five-year overall survival (OS) and event-free survival (EFS) rates were 84.7% and 38.6%, respectively. In multivariable analysis, EFS was significantly worse in case of nonsurgical treatment, alcohol consumption, and glossotonsillar sulcus involvement. N-positive status was the only significant prognostic factor for OS in multivariable analysis. Salivary carcinomas of the tongue represent a heterogeneous group of rare tumors, with a high risk of recurrence. In this national cohort, surgery was associated with better EFS and N-status was the main independent prognostic factor for OS.

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios as Predictors of Dysphagia Severity and Quality of Life in Nasopharyngeal Cancer Patients after Intensity Modulated Radiotherapy (IMRT).

Background: Patients treated with definitive radiotherapy for nasopharyngeal carcinoma (NPC) develop severe dysphagia, affecting their quality of life. Traditional prognosis biomarkers are insufficient, leading to a search for new predictors like neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Methods: We retrospectively enrolled 44 NPC patients who underwent definitive radiotherapy between 2010 and 2018. EQUATOR and STROBE network guidelines were adopted. Pre-treatment evaluations were conducted, and post-treatment oropharyngeal dysphagia was assessed using the Sydney Swallow Questionnaire (SSQ) and FEES, then assigning a Dysphagia Outcome and Severity Scale (DOSS) level. Patients were divided based on NLR and PLR cut-offs, comparing subjective dysphagia (SSQ) scores and DOSS results at baseline and after a 5-year follow-up. Multiple linear regression was used for analysis. Results: At baseline, the mean NLR was 2.52 ± 1.10, and the PLR was 208.40 ± 94.35. Multivariate analysis indicated NLR and PLR as significant predictors of DOSS outcomes (p < 0.001). Conclusions: Baseline inflammation markers, such as NLR and PLR, may be used to predict dysphagia severity in NPC patients undergoing definitive radiotherapy. These markers could help identify patients at higher risk for severe dysphagia and implement tailored therapeutic and rehabilitative strategies to improve their quality of life. Further studies with larger cohorts are needed to confirm these findings and explore additional prognostic factors for dysphagia outcomes in NPC patients.

Concordance in bacterial colonization profiles between voice prostheses and oral microbiota post-laryngectomy: An experimental study.

OBJECTIVE: Knowledge about voice prosthesis microbial colonization is vital in laryngectomized patients' quality of life (QoL). Herein, we aimed to explore the relationship between oral microbial patterns, demographic variables and voice prosthesis performance. METHODS: Thirty laryngectomy patients were assessed for microbial colonization in their voice prostheses and oral cavities. Factors like age, proton pump inhibitor (PPI) usage, and alcohol consumption were considered. RESULTS: Participants' average age was 74.20 ± 7.31 years, with a majority on PPIs. Staphylococcus aureus was the most common bacterium in prostheses (53 %), followed by Pseudomonas aeruginosa (27 %). Candida albicans was the primary fungal colonizer (67 %). A statistically significant moderate correlation was found between fungal species before and after oral rinsing (p = 0.035, Phi=0.588, Cramer's V = 0.416). Voice prosthesis and oral cavity microbiota profiles showed significant concordance (kappa=0.315, p < 0.004). Among subgroup analyses, bacterial patterns of colonization did not significantly influence VHI (p = 0.9555), VrQoL (p = 0.6610), or SF-36 (p = 0.509) scores. Conversely, fungal patterns of VP colonization significantly impacted subjective voice scores, with Candida krusei demonstrating better VHI (35.25 ± 3.63 vs. 44.54 ± 6.33; p = 0.008), VrQoL (7.13 ± 1.69 vs. 10.73 ± 2.00; p = 0.001), and SF-36 (69.36 ± 7.09 vs. 76.50 ± 7.73; p = 0.051) scores compared to C. albicans. CONCLUSIONS: There was a significant correlation between the oral microbiota and voice prosthesis colonization. These insights can inform improved care strategies for voice prostheses, enhancing patient outcomes.

Perception of Young European Otolaryngologists toward Transoral Robotic Surgery in Head and Neck Oncology and Surgery.

Background: To investigate the perception of young European otolaryngologists (OTOs), i.e., head and neck surgeons, toward transoral robotic surgery (TORS). Methods: Members of the Young Confederation of European Otorhinolaryngology-Head and Neck Surgery and Young Otolaryngologists of International Federation of Otorhinolaryngological Societies were surveyed about TORS perception and practice. Results: The survey was completed by 120 young OTOS (26%). The most important barriers to TORS were robot availability (73%), cost (69%), and lack of training (37%). The participants believed that the main benefits include better surgical filed view (64%), shorter hospital stay (62%), and better postoperative outcomes (61%) than the conventional approach. Head and neck surgeons considered cT1-T2 oropharyngeal cancers (94%), resection of base of tongue for sleep apnea (86%), or primary unknown cancer (76%) as the most appropriate indications. A total of 67% of TORS surgeons assessed themselves as adequately trained in TORS. Conclusions: Young European OTOs report positive perception, adoption, and knowledge of TORS. The cost-related unavailability and the lack of training or access are reported to be the most important barriers for the spread of TORS.

Past, Present, and Future Diagnostic Methods for the Early Noninvasive Detection of Oral Premalignant Lesions: A State of the Art and Systematic Review.

Objectives: To provide an in-depth analysis of noninvasive methods for the early diagnosis of oral premalignant lesions, focusing on novel biomarkers and optical technologies, and to discuss their potential in improving the prognosis of patients with oral oncological diseases. Methods: This state-of-the-art review examines various noninvasive diagnostic techniques, including the utilization of salivary microRNAs and optical technologies such as Raman spectroscopy, elastic scattering spectroscopy, diffuse reflectance spectroscopy, narrow-band imaging, autofluorescence imaging, toluidine blue staining, and microendoscopy. Results: Several noninvasive techniques have shown varying degrees of effectiveness in detecting oral cancer. Autofluorescence imaging exhibited sensitivities up to 100% but had variable specificity. toluidine blue staining reported sensitivity between 77% and 100% for high-risk lesions or cancer, with specificity around 45% to 67%. Spectroscopy techniques achieved 72% to 100% sensitivities and specificities of 75% to 98%. Microendoscopy presented a sensitivity of 84% to 95% and a specificity of 91% to 95%. Conclusion: The review highlights the strengths and limitations of each noninvasive diagnostic method and their recent advancements. Although promising results have been demonstrated, there is a need for further development of reliable strategies for early detection and intervention in oral oncology.

Parotid cancer: analysis of preoperative parameters for adaptation of the therapeutic strategy.

PURPOSE: To establish typical clinical and radiological profiles of primary low-grade parotid cancers in order to tailor therapeutic strategy. MATERIALS AND METHODS: Retrospective study of 57 patients operated on for primary parotid cancer between 2010 and 2021, with review of preoperative MRI and histopathology according to a standardized scoring grid. OBJECTIVE: To study prognostic factors and determine the preoperative clinical and radiological profile of low-grade cancers. RESULTS: Good prognostic factors for specific survival were: staging ≤ cT3 (p = 0.014), absence of adenopathy on cN0 MRI (p < 0.001), superficial lobe location (p = 0.033), pN0 (p < 0.001), absence of capsular rupture (p = 0.004), as well as the absence of peri-tumoral nodules (p = 0.033), intra-parotid adenopathies (p < 0.001), vascular emboli (p < 0.001), peri-neural sheathing (p = 0.016), nuclear atypia (p = 0.031), and necrosis (p = 0.002). It was not possible to define a reliable clinical and radiological profile for low-grade cancers (sensitivity 38%, specificity 79%). CONCLUSION: Our study demonstrated multiple factors of good prognosis, but it was not possible to define a clinical and radiological profile of patients likely to benefit from more limited surgery, nor to diagnose, a priori, low-grade cancers.

Twelve years after: The french national network on rare head and neck tumours (REFCOR).

BACKGROUND: Rare cancers constitute less than 10% of head and neck cancers and lack sufficient evidence for standardized care. The French Rare Head and Neck Cancer Expert Network (REFCOR) as established a national database to collect data on these rare cancers. This study aims to describe patient and tumour characteristics in this database. METHODS: Prospective data collection was conducted across multiple centers. Survival analyses were performed using Kaplan Meier method and Log Rank test. Odds ratios were used for comparing proportions. RESULTS: A total of 7208 patients were included over a period of 10 years. The most frequent histologies were: Not Otherwise Specified (NOS) adenocarcinoma 13 %, adenoid cystic carcinoma 12 %, squamous cell carcinoma of rare locations 10 %, mucoepidermoid carcinoma 9 %, intestinal-type adenocarcinoma (8 %). Tumours were located in sinonasal area (38 %); salivary glands (32 %); oral cavity / oropharynx / nasopharynx (16 %); larynx / hypopharynx (3 %); ears (1 %); others (3 %). Tumours were predominantly classified as T4 (23 %), N0 (54 %), and M0 (62 %). Primary treatment approach involved tumour resection (78 %) and / or radiotherapy (63 %). Patients with salivary gland cancers exhibited better 5-year overall survival (OS) rates (p < 0.05), and lower recurrence rates compared to patients with sinonasal, laryngeal/ hypopharyngeal cancers. No significant differences were observed in the other comparisons. Acinar cell carcinoma demonstrated the best OS while mucous melanoma had the poorest prognosis. CONCLUSION: Melanoma, carcinoma NOS, and sinonasal undifferenciated carcinoma still have poor prognoses. Efforts are being made, including training and guidelines, to expand network coverage (REFCOR, EURACAN), improve data collection and contribute to personalized therapies.

Correlation between MRI (DWI and DCE) and cellularity of parotid gland pleomorphic adenomas.

PURPOSE: Parotid pleomorphic adenomas present a risk of recurrence, higher when the tumour is a hypocellular subtype. The aim of the study was to determine whether it is possible to characterize this histological subtype with diffusion and perfusion sequences of the preoperative MRI. METHODS: This retrospective study included 97 patients operated between 2010 and 2020. Histologic slides review was performed to classify tumours into three histologic subtypes: hypocellular, classical and hypercellular. Univariate and multivariate analyses studied the correlation between histology and diffusion and perfusion MRI parameters obtained with OleaSphere® software. RESULTS: The hypocellular subtype had higher apparent diffusion coefficient values than the other two subtypes: 2.13 ± 0.23, 1.83 ± 0.42, and 1.61 ± 0.4 × 10-3 mm2/s for hypocellular, classical and hypercellular subtype respectively (p < 0.0001). Multivariate analysis showed that an ADCmean > 1.88 × 10-3 mm2/s was suggestive of a hypocellular pleomorphic adenoma in 79% of the cases, with a specificity and PPV of 94 and 96% (p < 0.001), respectively. CONCLUSION: The histological subtype of a pleomorphic adenoma can be predicted preoperatively with ADC values. A prospective and multicentric study on a larger cohort is needed to confirm our results.

[French national standard for the treatment of squamous cell carcinoma of upper aero-digestive tract - General principles of treatment]. / Référentiel national de traitement des carcinomes épidermoïdes des voies aérodigestives supérieures ­ Principes généraux de traitement.

OBJECTIVES: The management of upper aerodigestive tract cancers is a complex specialty. It is essential to provide an update to establish optimal care. At the initiative of the INCa and under the auspices of the SFORL, the scientific committee, led by Professor Béatrix Barry, Dr. Gilles Dolivet, and Dr. Dominique De Raucourt, decided to develop a reference framework aimed at defining, in a scientific and consensus-based manner, the general principles of treatment for upper aerodigestive tract cancers applicable to all sub-locations. METHODOLOGY: To develop this framework, a multidisciplinary team of practitioners was formed. A systematic analysis of the literature was conducted to produce recommendations classified by grades, in accordance with the standards of the French National Authority for Health (HAS). RESULTS: The grading of recommendations according to HAS standards has allowed the establishment of a reference for patient care based on several criteria. In this framework, patients benefit from differentiated care based on prognostic factors they present (age, comorbidities, TNM status, HPV status, etc.), conditions of implementation, and quality criteria for indicated surgery (operability, resectability, margin quality, mutilation, salvage surgery), as well as quality criteria for radiotherapy (target volume, implementation time, etc.). The role of medical and postoperative treatments was also evaluated based on specific criteria. Finally, supportive care must be organized from the beginning and throughout the patients' care journey. CONCLUSION: All collected data have led to the development of a comprehensive framework aimed at harmonizing practices nationally, facilitating decision-making in multidisciplinary consultation meetings, promoting equality in practices, and providing a state-of-the-art and reference practices for assessing the quality of care. This new framework is intended to be updated every 5 years to best reflect the latest advances in the field.

Carcinomas of the external auditory canal: Management and results: A multicenter REFCOR propensity score matching study.

OBJECTIVES: To analyse prognostic factors and survival outcomes of malignant tumors of the external auditory canal, to investigate the role of regional surgery, and adjuvant radiotherapy in early stages and to investigate the role of surgery in operable T4 stage. SETTING: A retrospective analysis was conducted on all patients prospectively included in the national database of the French Expertize Network for Rare ENT Cancers (REFCOR) from January 2000 to December 2016. PARTICIPANTS: 103 patients from 19 reference centers were included. A propensity score matching analysis was applied to enable comparisons between treatments. MAIN OUTCOMES AND MEASURES: Event-free survival, overall survival and factors of poor prognosis of the cohort were described. The interest of local and regional surgery and postoperative radiotherapy were evaluated. RESULTS: The factors of poor prognosis on event-free survival were immunosuppression (p = 0.002), Karnofsky status less than 90% (p = 0.02), body mass index less than 19 Kg / m2 (p = 0.0009), peripheric facial palsy (p = 0.0016), and positive margin (p = 0.0006). In early stages, locoregional surgery was associated with an increase in event-free survival (p = 0.003, HR = 0.21) versus local surgery alone, while postoperative radiotherapy was not associated with an increase in event-free survival (p = 0.86, HR = 0.91) or overall (p = 0.86, HR = 0.91). In locally advanced stages, locoregional surgery followed by radiotherapy was associated with an increase in event-free survival (p = 0.03, HR = 0.39) and overall (p = 0.02, HR = 0.34) versus chemoradiotherapy alone. CONCLUSION AND RELEVANCE: Regional surgery is recommended for early stages of cancers of the external auditory canal. In operable cases, locoregional surgery followed by radiotherapy is recommended.

Functional or radical surgical treatment of laryngeal chondrosarcoma, analysis of survival and prognostic factors: A REFCOR and NetSarc-ResOs multicenter study of 74 cases.

INTRODUCTION: Laryngeal chondrosarcoma (LCS) is a rare tumor of slow evolution whose treatment is poorly codified. For a long time, a radical treatment by total laryngectomy (TL) was proposed. More recent studies tend to propose a conservative surgical approach of the larynx. The objective of this study was to compare the overall survival (OS) of total laryngectomized patients (TL+) versus non-laryngectomized patients (TL-). The secondary objectives were to analyse the reoperation free survival (RFS), the total laryngectomy free survival (TLFS) and to identify the preoperative factors leading surgeons to propose TL. MATERIALS AND METHODS: A retrospective analysis of prospectively collected incident cases from the REFCOR and NetSarc-ResOs multicenter databases between March 1997 and June 2021 was conducted. A propensity score matching analysis was performed to compare the OS of TL+ and TL-patients. RESULTS: 74 patients were included. After propensity score, the 5-year OS of TL+ and TL-patients was comparable (100 %, p = 1). The 5-year RFS rate was 69.2 % (95 % CI [57.5-83.4]) and the 5-year TLFS was 61.7 % (95 % CI [50.4-75.5]). Cricoid involvement greater than 50 % (HR 3.58; IC 95 % [1.61-7.92] p < 0.001), an ASA score of 3 or 4 (HR 5.07; IC 95 % [1.64-15.67] p = 0.009) and involvement of several cartilages (HR 5.26; IC 95 % [1.17-23.6] p = 0.04) are prognostic factors for TL. Dyspnea caused by the tumour is a prognostic factor for reoperation (HR 2.59; IC 95 % [1.04-6.45] p = 0.03). CONCLUSION: These results demonstrate that conservative treatment should be considered as first-line treatment for laryngeal chondrosarcoma.

Effectiveness and rapidity on olfatory fuction recovery in CRS patients treated with Dupilumab: a real life prospective controlled study.

BACKGROUND: Recovery of olfactory function plays a prominent role in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). While rates and timing of such recovery vary, monoclonal antibodies might yield better results which we aimed at evaluating with this study. METHODOLOGY: A prospective controlled study was conducted at our tertiary otolaryngological center from April 1, 2021, to October 1, 2022, in CRSwNP patients. We included an active group (n = 60 patients) performing dupilumab treatment and a control group (n = 60 patients) treated with intranasal and oral corticosteroids. Primary endpoints were changes in smell visual analogical scale (VAS) and SS-I (Sniffin' Sticks-identification) scores, and olfactory recovery rate. The secondary efficacy endpoints were nasal obstruction, rhinorrhea, headache, SNOT-22, and nasal congestion score (NCS). RESULTS: At 6 months, the active group demonstrated better outcomes than control in SS-I scores (10.23 ± 4.21 vs.3.68 ± 3.08; p < 0.001). No significant differences were found in blood eosinophil count, SNOT-22, and NPS (p > 0.05 for all). Olfactory function in the treatment arm improved in 86.66% (52/60 cases), with normal scores in 48.33% (29/60), while the control group reported a lower recovery rate (3/60; 5%), with no normal olfaction cases. Log-rank comparison for Kaplan-Meier functions was statistically significant (p < 0.001), but no differences were found in subanalysis in the active group based on blood eosinophil count at baseline, SNOT-22, and NPS scores. CONCLUSIONS: Patients who receive dupilumab treatment may experience a faster recovery of olfactory function compared to those receiving corticosteroid therapy. This result would be maintained regardless of the severity of type 2 CRSwNP inflammation, the volume of the polyps, or the patient's subjective symptomatology.

Laser Hair Removal for Intraoral Flaps: A Review.

Importance: Laser hair removal is a noninvasive technique that has been used for patients with oropharyngolaryngeal hair growth related to surgical flap reconstruction after head and neck cancer resection. The purpose of this work was to perform a rapid review of the literature to determine the therapeutic relevance of laser hair removal and identify laser parameters. Observations: A total of 10 publications addressing depilation of the head and neck sphere were selected and analyzed. Conclusions and Relevance: Laser therapy appears to be a promising treatment for hair removal from flaps with few side effects. However, there is no scientific basis for a standardized protocol or determination of the superiority of laser hair removal over another treatment.

Influence of Otolaryngological Subspecialties on Perception of Transoral Robotic Surgery: An International YO-IFOS Survey.

BACKGROUND: To investigate perception, adoption, and awareness on the part of otolaryngology and head and neck surgeons (OTO-HNS) of transoral robotic surgery (TORS). METHODS: Several items assessed: awareness/perception; access to TORS; training; indications and advantages/hurdles to TORS practice. A subanalysis was performed to assess differences according to the identified otolaryngological subspecialties. RESULTS: A total of 359 people completed the survey. Among subspecialties, while for otolaryngologists 30/359 (8.4%) and H&N surgeons 100/359 (27.9%) TORS plays an effective role in hospital stay, laryngologists frequently disagreed (54.3%). There was a lower incidence among rhinologists and otologists (1.9%). Pediatric surgeons (0.8%) reported a positive response regarding the adoption of robotic surgery, and head and neck specialists expressed an even greater response (14.2%). Low adherence was related to perceived cost-prohibitive TORS, by 50% of H&N surgeons. CONCLUSIONS: Perception, adoption, and knowledge about TORS play a key role in the application of the robotic system, significantly varying across subspecialties.

Marginal versus Segmental Mandibulectomy in the Treatment of Oral Cavity Cancer: A Systematic Review and Meta-analysis.

Introduction Oral cavity squamous cell carcinoma (OCSCC) is the most common malignancy in the oral cavity. Two types of mandibular resections have been described: the segmental mandibulectomy and the marginal mandibulectomy. Both may have a different impact over the quality of life, oncological prognosis, and functional or aesthetic result. Objectives The aim of this study was to systematically explore the literature to determine the survival outcomes and disease control rates in patients who underwent segmental or marginal mandibulectomy for OCSCC with histological evidence of cortical and medullary bone invasion. Data Synthesis This review involved a systematic search of the electronic databases MEDLINE/PUBMED, Google Scholar, Ovid Medline, Embase, and Scopus including articles from 1985 to 2019. Fifteen articles were included for qualitative analysis and 11 articles were considered for meta-analysis calculations. All of them correspond to retrospective cohort studies. Conclusion This systematic review reveals the low-level evidence regarding the impact over local control or survival according to the type of mandibulectomy. Our results need to be considered with precaution according to the limited evidence available. We just found difference regarding the 5-year disease-free survival, and a tendency in favor of segmental mandibulectomy was confirmed when medullary invasion was evident.

Biomarkers in Laryngeal Squamous Cell Carcinoma: The Literature Review.

Laryngeal squamous cell carcinoma (LSCC) is the second most common cancer among head and neck cancers. Despite a lower incidence of laryngeal carcinoma, new diagnostic techniques, and more targeted therapies, the overall survival has not changed significantly in the last decades, leading to a negative prognosis in advanced stages. Recently, several studies have focused on the identification of biomarkers that may play a critical role in the pathogenesis of LSCC. Reviewing the literature on the main databases, this study aims to investigate the role of some biomarkers in LSCC that are correlated with oxidative stress and inflammation: heat shock proteins; metallothioneins; nuclear factor erythroid 2-related factor 2; heme oxygenase; cyclooxygenase-2; and micro ribonucleic acids. This review shows that biomarker expression depends on the type, grade of differentiation, stage, and site of carcinoma. In addition, the role of these biomarkers in LSCC is still little-known and little-studied. However, the study of biomarker expression and the detection of a possible correlation with patients' epidemiological, clinicopathological, and therapeutics data may lead to better awareness and knowledge of the tumor, to the identification of the best therapeutic strategy, and the most proper follow-up protocol tailored for each patient. In conclusion, the achievement of these goals may improve the prognosis of LSCC patients.

Adding automated decision-tree models to multiparametric MRI for parotid tumours improves clinical performance.

PURPOSE: Therapeutic management of parotid gland tumours depends on their histological type. To aid its characterisation, we sought to develop automated decision-tree models based on multiparametric magnetic resonance imaging (MRI) parameters and to evaluate their added diagnostic value compared with morphological sequences. METHODS: 206 MRIs from 206 patients with histologically proven parotid gland tumours were included from January 2009 to January 2018. Multiparametric MRI findings (including parameters derived from diffusion-weighted imaging [DWI] and dynamic contrast-enhanced [DCE]) were used to build predictive classification and regression tree (CART) models for each histological type. All MRIs were read twice: first, based on morphological sequence findings only, and second, with the addition of multiparametric sequences and CART findings. The diagnostic performance between these two readings was compared using ROC curves. RESULTS: Compared to morphological sequences alone, the addition of multiparametric analysis significantly increased the diagnostic performance for all histological types (p < 0.001 to p = 0.011), except for lymphomas, where the increase was not significant (AUC 1.00 vs. 0.99, p = 0.066). ADCmean was the best parameter to identify pleomorphic adenomas, carcinomas and lymphomas with respective cut-offs of 1.292 × 10-3 mm2/s, 1.181 × 10-3 mm2/s and 0.611 × 10-3 mm2/s, respectively. × 10-3 mm2/s. The mean extracellular-extravascular space coefficient was the best parameter to Warthin tumours from the others, with a cut-off of 0.07. CONCLUSIONS: The addition of decision tree prediction models based on multiparametric sequences improves the non-invasive diagnostic performance of parotid gland tumours. ADC and extracellular-extravascular space coefficient are the two best parameters for decision making.