***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer . We undertook a prospect i ve study of the effect on xerostomia and outcomes of sparing one or both parotid gl and s during radiotherapy for patients with squamous cell carcinoma of the head and neck . Methods and material s Patients with locally advanced squamous cell carcinoma of the head and neck received definitive ( 70 Gy in 2 Gy fractions ) or adjuvant ( 60–66 Gy in 2 Gy fractions ) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate . Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid . Results The study included 126 patients ; 114 ( 55 in group A and 59 in group B ) had follow-up data . There were no statistically significant differences between groups in disease stage . Xerostomia was significantly reduced in group A vs. group B ( p = 0.0381 ) . Patients in group A also had significantly less dysphagia . Relapse-free and overall survival were not compromised in group A : 2-year relapse-free survival was 86 % vs. 72 % in group B ( p = 0.361 ) ; 2-year overall survival was 88 % and 76 % , respectively ( p = 0.251 ) . Conclusion This analysis suggests that reducing radiotherapy doses to both parotid gl and s to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival . Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be st and ard practice .ZusammenfassungZielFür Patienten mit Kopf-Hals-Tumoren ist die Xerostomie nach Strahlentherapie ein häufiges Problem . I m Rahmen einer prospektiven Studie haben wir untersucht , inwieweit die Schonung nur einer oder beider Parotiden das Ausmaß der Xerostomie und das Therapieergebnis beeinflusst . Patienten und Method enPatienten mit lokal fortgeschrittenem Plattenepithelkarzinom i m Kopf-Hals-Bereich wurden primär ( 70 Gy , 2 Gy pro Fraktion ) oder adjuvant ( 60–66 Gy , 2 Gy pro Fraktion ) mit kurativer Intention mit der helikalen Tomotherapie bestrahlt . Bei entsprechender Indikation wurde simultan eine platinbasierte Chemotherapie appliziert . Die Parotiden der Patienten der Gruppe A erhielten beide jeweils < 26 Gy , während in Gruppe B nur eine der beiden Parotiden mit < 26 Gy bestrahlt wurde . Ergebnisse126 Patienten wurden eingeschlossen , von denen 114 systematisch nachgesorgt werden konnten , 55 in Gruppe A und 59 in Gruppe B. Bezüglich der Tumorstadien best and statistisch zwischen den Gruppen kein Unterschied . Die Xerostomierate war in Gruppe A signifikant geringer als in Gruppe B ( p = 0,0381 ) . Bei signifikant weniger Patienten der Gruppe A kam es zu einer Dysphagie ( p = 0,0032 ) . Das rezidivfreie Überleben und das Gesamtüberleben waren nicht beeinträchtigt ; das rezidivfreie Überleben nach 2 Jahren betrug 86 % in Gruppe A versus 72 % in Gruppe B ( p = 0,361 ) ; das Gesamtüberleben nach 2 Jahren lag bei 88 % in Gruppe A versus 76 % in Gruppe B ( p = 0,251).SchlussfolgerungBei der Diskussion um Parotisschonung/Dosisbelastung ist es entscheidend , dass jede Parotis individuell zu betrachten ist und nicht der Mittelwert über beide . Diese Ergebnisse zeigen , dass siginifikant weniger Patienten eine Xerostomie und Dysphagie entwickeln , wenn beide Parotiden mit < 26 Gy belastet werden , ohne dass das Gesamtüberleben oder das rezidivfreie Überleben negativ beeinträchtigt werden CONTEXT Radiotherapy techniques have improved over years but have also raised concerns over subsequent acute and late effects . One such complication , dysphagia , has led to much interest and optimization in treatment delivery . AIMS The aim of this study was to compare radiation dose to dysphagia aspiration related structures ( DARS ) in intensity modulated radiation therapy ( IMRT ) and three-dimensional conformal radiotherapy ( 3DCRT ) , and assess its relation to post-treatment swallowing status , in patients of carcinoma of the anterior two thirds of tongue . MATERIAL S AND METHODS Treatment plans of patients treated with IMRT and 3DCRT , from November 2011 to December 2012 , were retrieved . Swallowing structures were contoured . Dose volume histograms were generated . Constraint doses were considered based on the statistical derivations . Swallowing status was evaluated based on University of Washington Head- and Neck-related Quality -of-Life questions addressing swallowing . STATISTICAL ANALYSIS USED IBM SPSS Statistics 20 Windows ( SPSS Inc. , Chicago , IL , USA ) was used . Mann-Whitney U-test , Spearman 's rho correlation coefficient , and receiver operating curves were used . RESULTS Definitive statistical and subjective correlations were found to exist between doses of swallowing structures , especially the constrictor muscles , the base of the tongue and larynx . Probable mean dose constraints derived statistically clinical ly corroborates with the swallowing status of patients . IMRT had statistically significant advantage over 3DCRT , in terms of V30 ( P - 0.051 ) , V50 ( P - 0.002 ) , V60 ( P - 0.002 ) , and D80 ( P - 0.023 ) for swallowing structures taken together . CONCLUSION Our study is probably one of the few studies predicting possible mean dose constraints for superior constrictor , the base of the tongue and larynx . Further prospect i ve studies are required to confirm these and to improve the swallowing quality OBJECTIVES To characterize and compare quality of life ( QOL ) in patients with head and neck cancer shortly before initial treatment and 1 year later and to study the predictors of changes in QOL over 1 year . DESIGN Prospect i ve cohort study . SETTING Three otolaryngology clinics . PATIENTS Three hundred sixteen patients having newly diagnosed squamous cell head and neck cancer . MAIN OUTCOME MEASURE Health-related QOL was assessed using the  36-item Short-Form Health Survey  and a head and neck cancer-specific QOL scale .  RESULTS Over 1 year , QOL decreased for physical functioning measures and eating but improved for mental health QOL . Depression and smoking were major predictors of poor QOL at baseline . Major predictors of change in QOL from baseline to 1 year were treatment factors , especially feeding tube placement ( 9 scales ) , chemotherapy ( 3 scales ) , and radiation therapy ( 3 scales ) . Baseline smoking and depressive symptoms also remained significant predictors of several QOL scales at 1 year . CONCLUSIONS Health-related physical QOL tended to decline over 1 year and mental health QOL improved . The major predictors of change in QOL were treatment factors , smoking , and depressive symptoms . Physicians should alert patients to the relative effects on QOL one may experience with different treatments PURPOSE To evaluate late dysphagia after chemoradiotherapy for locally advanced head- and -neck squamous cell carcinoma , and to examine its correlation with clinical and dosimetric parameters . METHODS AND MATERIAL S Consecutive patients , treated with radiotherapy ( 70 - 72 Gy ) and concomitant chemotherapy ( cisplatinum 100 mg/m(2 ) every 3 weeks ) between 2004 and 2007 , were examined . Swallowing was evaluated by four quality -of-life question naires : EORTC C30 and H&N35 , the Performance Status Scale of List , and the MD And erson Dysphagia Inventory . Clinical and dosimetric parameters were correlated with late dysphagia . RESULTS A total of 53 disease-free patients were evaluated ; mean follow-up was 20.4 months ( range , 6 - 45 months ) . The volume of the middle pharyngeal constrictor muscle receiving > or = 50 Gy ( p = 0.04 ) , the mean dose to this structure ( p = 0.02 ) and to the supraglottic larynx ( p = 0.04 ) were significantly associated with late swallowing problems at univariate analysis , along with tumor localization ( p = 0.008 ) , T-classification ( p = 0.02 ) , and pretreatment swallowing problems ( p = 0.01 ) . Only this last factor significantly correlated with late dysphagia at multivariate analysis . CONCLUSION These findings motivate further efforts to reduce the dose to the swallowing structures , especially to the pharyngeal constrictor muscles and the larynx . However , clinical parameters are also important and should be included in future prospect i ve trials PURPOSE To evaluate early swallowing after intensity-modulated radiotherapy for head and neck squamous cell carcinoma and determine factors correlating with aspiration and /or stricture . METHODS AND MATERIAL S Consecutive patients treated with intensity-modulated radiotherapy with or without chemotherapy between September 2004 and August 2006 at the Dana Farber Cancer Institute/Brigham and Women 's Hospital were evaluated with institutional review board approval . Patients underwent swallowing evaluation after completion of therapy ; including video swallow studies . The clinical - and treatment-related variables were examined for correlation with aspiration or strictures , as well as doses to the larynx , pharyngeal constrictor muscles , and cervical esophagus . The correlation was assessed with logistic regression analysis . RESULTS A total of 96 patients were evaluated . Their median age was 55 years , and 79 ( 82 % ) were men . The primary site of cancer was the oropharynx in 43 , hypopharynx/larynx in 17 , oral cavity in 13 , nasopharynx in 11 , maxillary sinus in 2 , and unknown primary in 10 . Of the 96 patients , 85 % underwent definitive RT and 15 % postoperative RT . Also , 28 patients underwent induction chemotherapy followed by concurrent chemotherapy , 59 received concurrent chemotherapy , and 9 patients underwent RT alone . The median follow-up was 10 months . Of the 96 patients , 31 ( 32 % ) had clinical ly significant aspiration and 36 ( 37 % ) developed a stricture . The radiation dose-volume metrics , including the volume of the larynx receiving > or=50 Gy ( p = 0.04 and p = 0.03 , respectively ) and volume of the inferior constrictor receiving > or=50 Gy ( p = 0.05 and p = 0.02 , respectively ) were significantly associated with both aspiration and stricture . The mean larynx dose correlated with aspiration ( p = 0.003 ) . Smoking history was the only clinical factor to correlate with stricture ( p = 0.05 ) but not aspiration . CONCLUSION Aspiration and stricture are common side effects after intensity-modulated radiotherapy for head- and -neck squamous cell carcinoma . The dose given to the larynx and inferior constrictors correlated with these side effects The purpose of this prospect i ve study was to evaluate the swallowing performance of patients with head and neck cancer treated with parotid‐sparing intensity‐modulated radiotherapy ( IMRT ) BACKGROUND The purpose of this study was to assess how xerostomia affects dysphagia . METHODS Prospect i ve longitudinal studies of 93 patients with oropharyngeal cancer treated with definitive chemotherapy-intensity-modulated radiotherapy ( IMRT ) .  Observer-rated dysphagia ( ORD ) , patient-reported dysphagia ( PRD ) , and patient-reported xerostomia ( PRX ) assessment of the swallowing mechanics by videofluoroscopy ( videofluoroscopy score ) , and salivary flow rates  , were prospect ively assessed from pretherapy through 2 years . RESULTS ORD grade s ≥2 were rare and therefore not modeled . Of patients with no/mild videofluoroscopy abnormalities , a substantial proportion had PRD that peaked 3 months posttherapy and subsequently improved . Through 2 years , highly significant correlations were observed between PRX and PRD scores for all patients , including those with no/mild videofluoroscopy abnormalities . Both PRX and videofluoroscopy scores were highly significantly associated with PRD . On multivariate analysis , PRX score was a stronger predictor of PRD than the videofluoroscopy score . CONCLUSION Xerostomia contributes significantly to PRD . Efforts to further decrease xerostomia , in addition to sparing parotid gl and s , may translate into improvements in PRD . © 2015 Wiley Periodicals , Inc. Head Neck 38 : E1605-E1612 , 2016 OBJECTIVE To evaluate changes in patient-perceived swallowing function over time following transoral robotic surgery ( TORS ) for primary T1 and T2 oropharyngeal squamous cell carcinomas . DESIGN Prospect i ve case series . SETTING Academic tertiary referral center . PATIENTS Forty-two patients with T1 or T2 oropharyngeal squamous cell carcinomas . INTERVENT 
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Furthermore , advanced tumor and nodal stage , pretreatment weight loss , ( concomitant ) chemotherapy and prophylactic gastrostomy policy were prognostic for tube feeding dependence ≥6months .
Prognostic patients /disease and treatment factors for tube feeding placement and use at less than 6months were similar to the prognostic factors for tube feeding dependence at ≥6months , but also included several unique variables such as the use of narcotics prior to treatment and living alone at the time of treatment