search
for
 About Bioline  All Journals  Testimonials  Membership  News


Journal of Cancer Research and Therapeutics
Medknow Publications on behalf of the Association of Radiation Oncologists of India (AROI)
ISSN: 0973-1482 EISSN: 1998-4138
Vol. 6, Num. 1, 2010, pp. 15-21

Journal of Cancer Research and Therapeutics, Vol. 6, No. 1, January-March, 2010, pp. 15-21

Original Article

Prospective subjective evaluation of swallowing function and dietary pattern in head and neck cancers treated with concomitant chemo-radiation

Departments of Radiation Oncology, 1 Surgical Oncology, 2 Interventional Radiology, 3 Speech Therapy, Tata Memorial Hospital, Mumbai, India

Correspondence Address: Dr J. P. Agarwal, Additional Professor, Department of Radiation Oncology, Tata Memorial Hospital, Mumbai-400012, India.

Code Number: cr10005

DOI: 10.4103/0973-1482.63563

Abstract

Aim : Prospective subjective evaluation of swallowing function and dietary pattern in locally advanced head and neck cancer patients treated with concomitant chemo-radiotherapy (CRT). Materials and Methods : Prospective evaluation of swallowing function with performance status scale for head and neck cancer patients (PSSHN) at pre-CRT, CRT completion and at subsequent follow-ups in adult with loco-regionally advanced head and neck squamous cell carcinoma (HNSCC) patients. Results : In 47 patients (40 male, seven females; mean age 53; 72% smoker 53%, oropharyngeal cancer), the mean total PSSHN score at pre-CRT was 258.5 and decreased to 225.2 and 219.2 at two and six months respectively. Understandability of speech, normalcy in diet and eating in public at pre-CRT and six months were 91.5 and 84.4; 80.4 and 63.1; 87.3 and 76.6 respectively. In univariate analysis, pre-CRT PSSHN scores were significantly lesser in patients with severe pre-CRT dysphagia (P = 0.001), hypopharyngeal cancer (P = 0.244) and advanced T-stage (T3/4) disease (P = 0.144). At CRT completion, there was significant reduction of PSSHN scores in patients with severe pre-CRT dysphagia (P = 0.008), post-CRT weight loss (>10%) and disease progression (P = 0.039). At two months and six months, 17 (57%) and 11 (73.5%) patients respectively showed change in dietary habit. Mean increase in meal time was 13% and 21% at two and six-month follow-up. Conclusions : HNSCC patients show deterioration in swallowing function after CRT with normalcy of diet in maximum and eating in public least affected. Pre-CRT severity of dysphagia, weight loss >10% and disease progression have significant correlation with higher swallowing function deterioration after CRT.

Keywords: Chemo-radiotherapy, developing countries, head and neck cancer, pattern in locally advanced head and neck, swallowing function

Introduction

In today's era, organ preservation is an important mile stone in the management of head and neck cancer. In loco-regionally advanced head and neck cancer concurrent chemo-radiation (CRT) is considered the standard of care for organ preservation. [1] Several large randomized studies and meta analyses have convincingly proven the equivalent survival with organ preservation approach compared with radical resection. [1],[2],[3] However, though organ preservation is possible with radiation therapy (RT), in recent years, a new debate regarding the 'functional status' of preserved organ with radiation has been started. [4] A few oncologists have shown serious doubt regarding the functional integrity of the preserved organ and thus utility for organ preservation at least in a subset of patient. Some believe that 'non functioning organ preservation' may cause more harm to the patient than complete excision. [5] The present day demand is to have 'functioning organ preservation,' which maintains and /or improves the quality of life.

A few small prospective and retrospective series have documented the functional status in loco-regionally advanced head and neck cancer of the organ after CRT. [6],[7],[8] However, literature is especially lacking in prospective detailed subjective and objective assessment of swallowing function. Thus, the onus is on the treating oncologists to provide functional outcome results of organ preservation with prospective studies involving large number of patients. The toxicity profile of patient not only depends upon the treatment modality used but also on patient related factors (e.g. nutritional status). Patient factors may vary with geographic and socio-economic status, thus it is imperative to have the toxicity profile in different patient population. [8],[9] On the other hand, pre-RT functional data is also important to provide impact of CRT at both early and long term functional outcome. The complex nature of assessment and interpretation of swallowing function may be the major reason for the limited prospective data. Impairment of swallowing function may be due to dryness of mouth (xerostomia), pain during deglutition, mucositis or even radiation induced fibrosis of 'dysphagia aspiration related structures' (DARS). [10],[11] Prospective objective evaluation may determine the impact of radiation on long term swallowing dysfunction. Consequences of dysphagia include dehydration, starvation, weight loss, aspiration pneumonia, airway obstruction and may also a cause of early mortality. [12],[13] Dysphagia may be in the form of 'labored' swallowing, prolonged eating times and limited range of foods that can be swallowed.

In the present analysis, early prospective swallowing function evaluation is done with both subjective and objective methodology at pre and post-radiation and compared with different patient related parameters.

Materials and Methods

In the period from September 2007 to November 2008, 47 consecutive head and neck cancer patients who were planned for RT and had fulfilled the present study criteria were accrued prospectively after procuring informed consent from the patient. This study was approved by the institutional scientific and ethics committee, which prospectively accrued histologically confirmed loco-regionally advanced (T1-4 N0-3 M0) non-nasopharyngeal squamous cell carcinoma patients (>18 years) of head and neck region (oropharynx/ hypopharynx / larynx) with good performance (KPS ≥ 70) and nutritional status. Patients with prior history of surgery, therapeutic irradiation (head and neck region) or chemotherapy were excluded. Majority of the patients were treated with conventional bilateral portal with reducing field technique (66-70 Gy / 33-35 #). In conformal radiotherapy (3 DCRT/IMRT), standard dose (GTV: 70 Gy / 30#, CTV: 60 Gy / 30#, 54 Gy / 30#) and constraints were prescribed. All Stage III/IV patients and four patients of Stage II with bulky disease received concomitant chemotherapy (cisplatin 30 mg / m 2 weekly). All patients were reviewed weekly for assessment of compliance to treatment, weight loss, performance status (KPS), skin and mucosal reactions (RTOG toxicity criteria), blood counts and need for supportive care (e.g. Ryle's tube, nutrition supplement). During treatment, patients were prescribed analgesics and local anesthetics. Pre-CRT swallowing function evaluation was done with subjective scale (Performance Status Scale for Head and Neck Cancer Patients [PSSHN]) and subjective dysphagia function was evaluated using standardized scale. [14],[15] In subjective dysphagia, evaluation score ranges from 0 to 6. Score 0 suggests no dysphagia and score 6 suggests 'nothing by mouth' . PSSHN is a questionnaire method for evaluation of subjective swallowing function. It has eating in public, understandability of speech and normalcy of diet domains. Each domain maximum and minimum scores were 0 and 100 respectively. Maximum total score is 300. Higher score indicates better swallowing function.

All the data was collected prospectively and analyzed with SPSS version 15. Demographic characteristics and results were summarized using mean, percentages, medians, and ranges. Pre-CRT, early post-treatment (two months post-CRT) and late post-treatment (six months post-CRT) parameters (KPS, weight loss, PSSHN) and side effect ratings were analyzed and compared using paired and unpaired t-test as appropriate.

Results

Among the 47 patients analyzed, there were 40 male, seven females; mean age 53 years (range 40-65 years); 72% smokers and with preserved performance (KPS> 70) and nutritional status [Table - 1]. Locally advanced oropharyngeal cancers (53%) were most common with commonest sub-site being base of tongue and pyriform fossa in oropharynx and hypo pharynx respectively. All patients completed CRT without any significant modification in treatment schedule.

At the time of analysis, all (n = 47) patients had completed two months and 26 patients had completed six-month follow-up. Among them, at two-month evaluation, one patient had died and 46 had follow-up evaluation. At six months, 19 patients had PSSHN evaluation, six died with disease progression and one patient was lost to follow-up.

Detailed PSSHN scores at pre-CRT and at subsequent follow-up were mentioned in [Table - 2]. Mean total score for PSSHN scale at pre-CRT was 258.5 and decreased to 225.2 at 2 month and 219.2 at 6 month follow up respectively. Normalcy of diet was 80.4 at pre-CRT and was reduced to 63.1 at two-month post-CRT. Eating in public domain score was 87.3 at pre-CRT, 76.1 at two months and was maintained to 76.6 at six-month follow-up. There was minimal disturbance in patient's speech with more than 77% patients' speech always understandable and 23% patients requiring occasional repetition of words. Half of the patients (50%) reported being comfortable eating in public places. 'Understandability of speech' was minimally affected whereas 'normalcy in diet' was impaired most at post-CRT evaluation [Figure - 1].

At pre-CRT evaluation, on univariate analysis, PSSHN score was significantly poor in patients with severe pre-CRT dysphagia score (dysphagia Grade 3-6) (P = 0.001) compared with patients with preserved dysphagia function (Grade 0-2) and markedly less in patients with hypo pharyngeal than non-hypo-pharyngeal cancer (P = 0.244) [Table - 3]. Lower T-stage (T1-2) patient's had better pre-CRT PSSHN score (276.3 versus 254.1; P = 0.144), However, patient related factors (age, gender), personal habits (smoking, tobacco chewing, alcohol use) or treatment related factors (overall treatment time) had not shown to significantly influence pre-CRT PSSHN score.

Patients with severe pre-CRT dysphagia (Grade 3-6) (P = 0.008), significant weight loss (>10%) at CRT completion and patients with disease progression (P = 0.039) had significantly higher reduction of PSSHN score at follow-up [Table - 4]. Patient-related factors such as age (P = 0.793), gender (P = 0.426), personal habits (P = 0.799), pre-RT hemoglobin levels (P = 0.218), site of primary (P = 0.536), T stage (P = 0.406), nodal stage (P = 0.782), AJCC stage, (P=0.412), overall treatment time (P = 0.190), grade of mucositis at RT completion (P = 0.538) and weight loss> 10% at two months (P = 0.186) evaluation had not shown any significant correlation with reduction in PSSHN score. Smokers, patients with early stage disease (T and N), smaller tumor volume (15 cm 2 ), overall treatment time > 48 days and with severe mucositis at RT completion had comparatively higher reduction in PSSHN score after CRT, though statistical significance was not achieved.

At pre-CRT, 31 patients (65%) were on solid diet, 16 (33%) on semisolid and only one patient (2%) was on liquid diet. At two-month and six-month post-CRT follow-up 33% and 26% patient were on solid food [Figure - 2]. At CRT conclusion, 11 (23.5%) patients were on feeding tube and at two months post-CRT; there were 12 (27%) .

Among the 31 patients on solid food at pre-CRT, 30 patients had two-month and 15 had six-month follow-up [Table - 5]. Among these patients, at two-month and six-month evaluation, 17/30 (57%) and 11/15 (73.5%) patients respectively required change in dietary habit to semisolid or liquid food. Mean increase in meal time in patients on solid food were only 13% and 21% at two and six-month follow-up from pre-CRT assessment. Weight loss was 8.8% at post-CRT two months and only 2.9% at six- month follow-up.

Discussion

In recent years, there has been great enthusiasm regarding quality of life, acute and late toxicities of different treatment modalities and these are being recognized as equally important as survival function. [10],[11],[12],[16] Prospective measurement of toxicity outcome is a tedious process but is critical in providing substantial evidences regarding the magnitude of toxicity with any treatment modality. Toxicity outcome not only depends on the treatment modality but is also closely related with various patient factors. Literature suggests that higher proportion of patients in developing countries have advanced disease at presentation compared with the developed country data. [17] Hence, toxicity profile of patients from developing countries with larger volume disease and poorer nutritional status may be different from developed countries. Implementation of 'treatment guidelines' obtained from western population should be appropriately adapted only after evaluation of toxicity parameters in the patient population concerned. [8]

In head and neck cancer, CRT is known to cause deterioration of swallowing function in both early and late post-CRT period. [18],[19],[20] CRT is the accepted standard of care as organ preservation strategies in loco-regionally advanced HNSCC, however, it is imperative for clinicians to assess the increased risk of dysphagia and aspiration with this treatment. [12],[13] Disease itself, poor oral hygiene, throat pain, mucositis, xerostomia, impairment of 'dysphagia aspiration related structures' (DARS) and also psychosocial factors plays adverse role in swallowing. [10],[11],[1],[18],[21] Though dysphagia has been described as an important acute and late toxicity of RT with or without CT, there is very sparse data regarding its objective assessment, especially from developing countries.

In our study, most of the patients had deterioration of total and sub-domain PSSHN scores at post-CRT follow-up evaluation. These findings matched with that of Stenson et al. and Salama et al. study which reported 60% patients had a worse dysphagia severity score after CRT. [22],[23] Normalcy of diet is mainly affected at two months post-CRT and was shown to deteriorate further in subsequent follow-ups. Magnitude of deterioration of total PSSHN scores at post-CRT evaluation corroborated consistently with the published western literature. [14],[17],[18],[19],[24] However, eating in public and understandability of speech is minimally affected in our patients. This may be due to influence of socio-cultural environment rather than treatment modality used. Patients had higher dysphagia scores due to acute toxicities of CRT at immediate post-CRT period, which decreased at two and six- month follow-up evaluation as reflected in PSSHN scores.

In literature, HNSCC patients treated with CRT had significantly higher swallowing dysfunction compared with RT alone. [14],[18] In RTOG 91-11 study, only 23% of patients treated with CRT (Cisplatin) were able to swallow soft foods at post CRT evaluation compared with 15% in RT alone arm and Only 9% patients on sequential Cisplatin/Fluorouracil had severe dysphagia. [24] The mean PSSHN scores of different prospective studies using conventional radiation therapy are described in [Table - 6]. The mean scores of different domains were similar in our study compared with the published western literature.

Patient and tumor related factors had influenced the change in PSSHN scores at post-CRT evaluation. Hypopharyngeal tumors, smokers, larger primary tumor volume, longer treatment time (> 48 days), patients with post-CRT> 10% weight loss, severe baseline dysphagia and disease progression are prone to have higher post-RT swallowing function deterioration. This suggests preservation of structure by itself does not ensure preservation of function. However, age at presentation, AJCC stage and pre-CRT hemoglobin level did not significantly influence post-CRT PSSHN scores. As expected, though T-stage had significant impact on swallowing function, N stage did not show any correlation. Longer treatment time may be due to treatment interruptions caused by severe acute toxicities during treatment, suggesting patients with high acute toxicities are also prone to have late squeals of CRT. [25] In literature, large primary tumor, hypo pharyngeal tumors and patients with disease progression had poorer post-treatment swallowing function. [7],[9],[20]

Mean weight had persistently reduced at subsequent post-CRT follow ups. Average weight loss was 8.5 kilograms from pre-CRT assessment and was matched with Connor et al. study. [24] Maximum reductions in weight was observed in immediate post-CRT two-month period, minimum during two to six months and there was a trend of increase in weight loss after six-month follow-up. In immediate post-CRT period, severe acute mucosal toxicity, change in taste, CRT-induced dysphagia and also anorexia played a role in weight reduction. In addition, xerostomia and inadequate dietary intake also contributed to weight loss. Majority of our patients had changed their dietary habits at subsequent follow-up. Conversion rate from solid to semisolid/ liquid food was high at follow-up. Our findings corroborated with Graner et al. and Machtay et al. findings who reported poor mean normalcy of diet score after CRT in head and neck cancer. [18],[19] List et al. also reported persistent restricted dietary habitat post CRT one year follow up evaluation. [17] There was only minimal increase in meal time in patients on solid food at follow-up.

Patients were encouraged to have feeding tube as and when required. However, acceptance of feeding tube was low in our patient population and only a small proportion of patients had naso gastric tubes while none had percutaneous endoscopic gastrostomy tube (PEG) insertion. Patients were strongly encouraged to maintain oral intake with high calorie diet as long as possible during treatment, In prospective organ preservation studies from developed countries 88% of patients were either on PEG or Ryle's tube feeding. [2],[3] On the contrary, in our study only 27% had feeding tube at two-month evaluation.

Though our study provides interesting information regarding swallowing function at pre-CRT and post-CRT follow-up, it is not devoid of limitations. In the era of conformal RT, majority of our patients were treated with 2-dimentional simulator based planning. PSSHN scoring methodology has not been validated in patient population from developing countries. In recent years, a lot of emphasis has been given to dysphagia aspiration related structure (DARS) and their constraints. Swallowing function is inherently related to DARS function and it will be interesting to see the outcomes with IMRT when appropriate DARS constraints are used. [20] However, in our study, the small cohort of patients treated with IMRT had not shown any significant preservation of PSSHN scores at post-CRT follow-up. All patients with abnormal swallowing should be encouraged for swallowing therapy and preferably take semisolid diet orally during and post-CRT period. At follow-up, special attention and appropriate referral should be given towards dietary advice.

In summary, the data clearly establish that CRT causes deterioration of swallowing function in majority of HNSCC patients. Normalcy of diet in mostly affected after RT. Conversion from solid to semisolid / liquid food was observed in majority of the patients. Eating in public was least affected and mainly due to socio-cultural reason. Patients with higher pre-CRT dysphagia score, weight loss> 10% and disease progression have significantly higher swallowing dysfunction after CRT. After six-month evaluation, there was a trend of higher weight loss, which may have been due to reduction in intensity of supervision, poorer compliance or due to disease progression. Dietary supervision needs to be reinforced for a longer duration after CRT. Larger and longer studies are needed to validate the data.[27]

References

1.Pignon JP, Bourhis J, Domenge C, Designι L. Chemotherapy added to locoregional treatment for head and neck squamous- cell carcinoma: Three meta-analyses of updated individual data: MACH-NC Collaborative Group: Meta-Analysis of Chemotherapy on head and neck cancer. Lancet 2000;355:949-55.  Back to cited text no. 1    
2.Forastiere AA, Goepfert H, Maor M, Pajak TF, Weber R, Morrison W, et al. Concurrent chemotherapy and radiotherapy for organ preservation in advanced laryngeal cancer. N Engl J Med 2003;349:2091-8.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.Fung K, Lyden TH, Lee J, Urba SG, Worden F, Eisbruch A, et al. Voice and swallowing outcomes of an organ-preservation trial for advanced laryngeal cancer. Int J Radiat Oncol Biol Phys 2005;63:1395-9.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]
4.Budach W, Hehr T, Budach V, Belka C, Dietz K. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck. BMC Cancer 2006;6:28.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]
5.Nguyen NP, Sallah S, Karlsson U, Antoine JE. Combined chemotherapy and radiation therapy for head and neck malignancies: Quality of life issues. Cancer 2002;94:1131-41.  Back to cited text no. 5  [PUBMED]  [FULLTEXT]
6.Smith RV, Goldman SY, Beitler JJ, Wadler SS. Decreased short- and long-term swallowing problems with altered radiotherapy dosing used in an organ sparing protocol for advanced pharyngeal carcinoma. Arch Otolaryngol Head Neck Surg 2004;130:831-6.  Back to cited text no. 6  [PUBMED]  [FULLTEXT]
7.Caudell JJ, Schaner PE, Meredith RF, Locher JL, Nabell LM, Carroll WR, et al. Factors associated with long-term dysphagia after definitive radiotherapy for locally advanced head-and-neck cancer. Int J Radiat Oncol Biol Phys 2009;73:410-5.  Back to cited text no. 7  [PUBMED]  [FULLTEXT]
8.Agarwal JP, Baccher GK, Waghmare CM, Mallick I, Ghosh-Laskar S, Budrukkar A, et al. Factors affecting the quality of voice in the early glottic cancer treated with radiotherapy. Radiother Oncol 2009;90:177-82.  Back to cited text no. 8  [PUBMED]  
9.Simental AA, Carrau RL. Assessment of swallowing function in patients with head and neck cancer. Curr Oncol Rep 2004;6:162-5.  Back to cited text no. 9  [PUBMED]  
10.Eisbruch A, Lyden T, Bradford CR, Dawson LA, Haxer MJ, Miller AE, et al. Objective assessment of swallowing dysfunction and aspiration after radiation concurrent with chemotherapy for head-and neck cancer. Int J Radiat Oncol Biol Phys 2002;53:23-8.   Back to cited text no. 10  [PUBMED]  [FULLTEXT]
11.Levendag PC, Teguh DN, Voet P, van der Est H, Noever I, de Kruijf WJ, et al. Dysphagia disorders in patients with cancer of the oropharynx are significantly affected by radiation therapy dose to the superior and middle constrictor muscle: A dose effect relationship. Radiother Oncol 2007;85:64-73.  Back to cited text no. 11  [PUBMED]  [FULLTEXT]
12.Nguyen NP, Frank C, Moltz CC, Vos P, Smith HJ, Bhamidipati PV, et al. Aspiration rate following chemoradiation for head and neck cancer: An underreported occurrence. Radiother Oncol 2006;80:302-6.  Back to cited text no. 12  [PUBMED]  [FULLTEXT]
13.Pedruzzi PA, Kowalski LP, Nishimoto IN, Oliveira BV, Tironi F, Ramos GH. Analysis of prognostic factors in patients with oropharyngeal squamous cell carcinoma treated with radiotherapy alone or in combination with systemic chemotherapy. Arch Otolaryngol Head Neck Surg 2008;134:1196-204.  Back to cited text no. 13  [PUBMED]  [FULLTEXT]
14.List MA, D'Antonio LL, Cella DF, Siston A, Mumby P, Haraf D, et al. The performance status scale for head and neck cancer patients and the functional assessment of cancer therapy-head and neck scale: A study of utility and validity. Cancer 1996;77:2294-301.  Back to cited text no. 14  [PUBMED]  
15.Waxman MJ, Durfee D, Moore M, Morantz RA, Koller W. Nutritional aspects of swallowing function of patients of Parkinson's disease. Nutr Clin Pract 1990;5:196-9.  Back to cited text no. 15  [PUBMED]  
16.Feng FY, Kim HM, Lyden TH, Haxer MJ, Feng M, Worden FP, et al. Intensity-modulated radiotherapy of head and neck cancer aiming to reduce dysphagia: Early dose-effect relationships for the swallowing structures. Int J Radiat Oncol Biol Phys 2007;68:1289-98.  Back to cited text no. 16  [PUBMED]  [FULLTEXT]
17.Parkin DM, Bray F, Ferlay J, Pisani P. Estimating the world cancer burden: Globocan 2000. Int J Cancer 2001;94:153-6.  Back to cited text no. 17  [PUBMED]  [FULLTEXT]
18.Machtay M, Rosenthal DI, Hershock D, Jones H, Williamson S, Greenberg MJ, et al. Organ preservation therapy using induction plus concurrent chemoradiation for advanced respectable oropharyngeal carcinoma: A University of Pennsylvania phase II trial. J Clin Oncol 2002;20:3964-71.  Back to cited text no. 18  [PUBMED]  [FULLTEXT]
19.Graner DE, Foote RL, Kasperbauer JL, Stoeckel RE, Okuno SH, Olsen KD, et al. Swallow function in patients before and after intra-arterial chemoradiation. Laryngoscope 2003;113:573-9.  Back to cited text no. 19  [PUBMED]  [FULLTEXT]
20.Colangelo LA, Logemann JA, Rademaker AW. Tumor size and pretreatment speech and swallowing with resectable tumors. Otolaryngol Head Neck Surg 2000;122:653-61.  Back to cited text no. 20  [PUBMED]  [FULLTEXT]
21.Eisbruch A, Schwartz M, Rasch C, Vineberg K, Damen E, Van As CJ, et al. Dysphagia and aspiration after chemoradiotherapy for head-and-neck cancer: Which anatomic structures are affected and can they be spared by IMRT? Int J Radiat Oncol Biol Phys 2004;60:1425-39.  Back to cited text no. 21  [PUBMED]  [FULLTEXT]
22.Jensen K, Bonde Jensen A, Grau C. The relationship between observer-based toxicity scoring and patient assessed symptom severity after treatment for head and neck cancer: A correlative cross sectional study of the DAHANCA toxicity scoring system and the EORTC quality of life questionnaires. Radiother Oncol 2006;78:298-5.  Back to cited text no. 22  [PUBMED]  [FULLTEXT]
23.Salama JK, Stenson KM, List MA, Mell LK, Maccracken E, Cohen EE, et al. Characteristics associated with swallowing changes after concurrent chemotherapy and radiotherapy in patients with head and neck cancer. Arch Otolaryngol Head Neck Surg 2008;134:1060-5.  Back to cited text no. 23  [PUBMED]  [FULLTEXT]
24.Connor NP, Cohen SB, Kammer RE, Sullivan PA, Brewer KA, Hong TS, et al. Impact of conventional radiotherapy on health related quality of life and critical functions of head and neck. Int J Radiat Oncol Biol Phys 2006;65:1051-62.  Back to cited text no. 24  [PUBMED]  [FULLTEXT]
25.Antognoni P, Corvς R, Zerini D, Orecchia R. Altered fractionation radiotherapy in head and neck cancer: Clinical issues and pitfalls of "evidence-based medicine". Tumori 2005;91:30-9.  Back to cited text no. 25    
26.Harrison LB, Zelefsky MJ, Pfister DG, Carper E, Raben A, Kraus DH, et al. Detailed quality of life assessment in patients treated with primary radiotherapy for squamous cell cancer of the base of the tongue. Head Neck 1997;19:169-75.  Back to cited text no. 26  [PUBMED]  [FULLTEXT]
27.Allal AS, Dulguerov P, Bieri S, Lehmann W, Kurtz JM. Assessment of quality of life in patients treated with accelerated radiotherapy for laryngeal and hypopharyngeal carcinomas. Head Neck 2000;22:288-93.  Back to cited text no. 27  [PUBMED]  [FULLTEXT]

Copyright 2010 - Journal of Cancer Research and Therapeutics


The following images related to this document are available:

Photo images

[cr10005f2.jpg] [cr10005t6.jpg] [cr10005f1.jpg] [cr10005t2.jpg] [cr10005t5.jpg] [cr10005t3.jpg] [cr10005t4.jpg] [cr10005t1.jpg]
Home Faq Resources Email Bioline
© Bioline International, 1989 - 2024, Site last up-dated on 01-Sep-2022.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Google Cloud Platform, GCP, Brazil