Prevention of radiation induced xerostomia by surgical transfer of submandibular salivary gland into the submental space

Obtaining a Reliable Diagnostic Biomarker for Diabetes Mellitus by Standardizing Salivary Glucose Measurements

Salivary glucose is frequently utilized in diabetes mellitus (DM), and it might be proposed as a potential biomarker candidate for DM, as it is non-invasive and cost-effective and achieves adequate diagnostic performance for DM patients. However, salivary glucose levels may change under specific conditions. It is consequently essential to maintain a consistent strategy for measuring saliva, taking into account the possibility of external factors influencing salivary glucose levels. In this study, we analyzed salivary glucose levels under different handling conditions and donor-dependent factors, including age, interdiurnal variations, and collection and processing methods. A structured questionnaire was used to determine the symptoms and predisposing factors of DM. The glucose oxidase peroxidase method was used to estimate glucose levels in the blood and saliva of people in a fasting state. The aim of this study is to investigate the effect of such conditions on salivary glucose levels. We found that these extraneous variables should be taken into account in the future when salivary glucose is used as a predictive biomarker for DM.

Quality of Life and Aesthetic Satisfaction in Patients Who Underwent the “Commando Operation” with Pectoralis Major Myocutaneus Flap Reconstruction—A Case Series Study

The “commando operation” is an extensive surgical procedure used to treat patients with oral squamous carcinoma and metastasis in the cervical lymph nodes. While the procedure can be curative, it is also very mutilating, which consequently has a major impact on the patient’s quality of life. Several studies showed that the procedure is associated with loss of certain functions, such as impairments in speech, chewing, swallowing, and loss of taste and appetite. Furthermore, some of these impairments and their degree depend on the reconstruction method. However, the data regarding the functional impairments and aesthetic results in patients who underwent the “commando operation” along with the pectoralis major myocutaneus flap reconstruction are still inconclusive. This study included 34 patients that underwent partial glossectomy, ipsilateral modified radical neck dissection, pectoralis major myocutaneus flap reconstruction, and adjuvant radiotherapy. A structured questionnaire was used to evaluate aesthetical results and functional impairments as well as to grade the level of satisfaction with the functional and aesthetic outcomes both by the patients and by the operator. Most of the patients stated that their speech (N = 33; 97%) and salivation (N = 32; 94.2%) severely changed after the operation and that they cannot chew (N = 33; 97%) and swallow (N = 33; 97%) the same as before the operation. Moreover, almost half of the patients (N = 16; 47%) reported that they have severe sleep impairments. However, only few of the included patients stated that they sought professional help regarding the speech (N = 4; 11.7%), eating (N = 5; 14.7%), and sleeping (N = 4; 11.7%) disturbances. Additionally, there was a statistically significant difference between the operator and the patients in the subjective assessment of the aesthetic results (p = 0.047), as operators gave significantly better grades. Our results imply that this procedure and reconstructive method possibly cause impairments that have an impact on the patients’ wellbeing. Moreover, our outcomes also suggest that patients should be educated and rehabilitated after the “commando operation” since most of them were reluctant to seek professional help regarding their impairments. Lastly, sleep deficiency, which was observed after the procedure, should be further explored.

Submandibular gland transfer for the prevention of radiation-induced xerostomia in oropharyngeal cancer: Dosimetric impact in the intensity modulated radiotherapy era

BACKGROUND

Submandibular gland (SMG) transfer decreased radiation-associated xerostomia in the 2/3-dimensional radiotherapy era. We evaluated the dosimetric implications of SMG transfer on modern intensity modulated radiotherapy (IMRT) plans.

METHODS

Eighteen oropharynx cancer patients underwent SMG transfer followed by IMRT; reoptimized plans using the baseline SMG location were generated. Mean salivary gland, oral cavity, and larynx doses were compared between clinical plans and reoptimized plans.

RESULTS

No statistically significant difference in mean SMG dose (27.53 Gy vs. 29.61 Gy) or total salivary gland dose (26.12 Gy vs. 26.41 Gy) was observed with or without SMG transfer (all p > 0.05). Mean oral cavity and larynx doses were not statistically different. Neither tumor site, target volume crossing midline, stage, nor salivary gland volumes were associated with mean doses.

CONCLUSIONS

Salivary gland doses were similar with or without SMG transfer. IMRT likely decreases the benefit of SMG transfer on the risk of radiation-associated xerostomia.

Radiation-Induced Salivary Gland Dysfunction: Mechanisms, Therapeutics and Future Directions

Salivary glands sustain collateral damage following radiotherapy (RT) to treat cancers of the head and neck, leading to complications, including mucositis, xerostomia and hyposalivation. Despite salivary gland-sparing techniques and modified dosing strategies, long-term hypofunction remains a significant problem. Current therapeutic interventions provide temporary symptom relief, but do not address irreversible glandular damage. In this review, we summarize the current understanding of mechanisms involved in RT-induced hyposalivation and provide a framework for future mechanistic studies. One glaring gap in published studies investigating RT-induced mechanisms of salivary gland dysfunction concerns the effect of irradiation on adjacent non-irradiated tissue via paracrine, autocrine and direct cell-cell interactions, coined the bystander effect in other models of RT-induced damage. We hypothesize that purinergic receptor signaling involving P2 nucleotide receptors may play a key role in mediating the bystander effect. We also discuss promising new therapeutic approaches to prevent salivary gland damage due to RT.

Salivary Gland Hypofunction and Xerostomia in Head and Neck Radiation Patients

BACKGROUND

The most manifest long-term consequences of radiation therapy in the head and neck cancer patient are salivary gland hypofunction and a sensation of oral dryness (xerostomia).

METHODS

This critical review addresses the consequences of radiation injury to salivary gland tissue, the clinical management of salivary gland hypofunction and xerostomia, and current and potential strategies to prevent or reduce radiation injury to salivary gland tissue or restore the function of radiation-injured salivary gland tissue.

RESULTS

Salivary gland hypofunction and xerostomia have severe implications for oral functioning, maintenance of oral and general health, and quality of life. Significant progress has been made to spare salivary gland function chiefly due to advances in radiation techniques. Other strategies have also been developed, e.g., radioprotectors, identification and preservation/expansion of salivary stem cells by stimulation with cholinergic muscarinic agonists, and application of new lubricating or stimulatory agents, surgical transfer of submandibular glands, and acupuncture.

CONCLUSION

Many advances to manage salivary gland hypofunction and xerostomia induced by radiation therapy still only offer partial protection since they are often of short duration, lack the protective effects of saliva, or potentially have significant adverse effects. Intensity-modulated radiation therapy (IMRT), and its next step, proton therapy, have the greatest potential as a management strategy for permanently preserving salivary gland function in head and neck cancer patients.Presently, gene transfer to supplement fluid formation and stem cell transfer to increase the regenerative potential in radiation-damaged salivary glands are promising approaches for regaining function and/or regeneration of radiation-damaged salivary gland tissue.

Involvement of the submandibular gland in oral squamous cell carcinoma patients with positive lymph nodes

BACKGROUND

No consensus exists about submandibular glands (SMGs) involvement in oral squamous cell carcinoma (OSCC) patients with cervical lymph node metastasis. We aimed to investigate the prevalence of SMG involvement in OSCC patients with positive lymph nodes.

METHODS

Retrospective analysis of data of 302 study subjects with positive lymph nodes in OSCC operated between January 2002 and December 2012.

RESULTS

Only 1/302 (0.3%) study subject had SMG involvement. The mode of spread was by direct extension of the primary carcinoma. Extracapsular spread of level IB lymph nodes was seen in 12/302 (4%) patients. Only one of these patients had involvement of the fibrous tissue around the SMG.

CONCLUSION

SMG involvement is very rare in OSCC patients with cervical lymph node metastasis. Preservation of the ipsilateral SMG during neck dissection might be oncologically safe when involvement by direct spread is unlikely.

Long-term outcomes of interventions for radiation-induced xerostomia: A review

Xerostomia, or dry mouth, is a significant problem affecting quality of life in patients treated with radiation therapy for head and neck cancer. Strategies for reduction of xerostomia burden vary widely, with options including: sialagogue medications, saliva substitutes, acupuncture, vitamins, hyperbaric oxygen, submandibular gland transfer, and acupuncture or associated treatments. In this review, we sought to evaluate long-term outcomes of patients treated with various interventions for radiation-induced xerostomia. A literature search was performed using the terms "xerostomia" and "radiation" or "radiotherapy"; all prospective clinical trials were evaluated, and only studies that reported 1 year follow up were included. The search results yielded 2193 studies, 1977 of which were in English. Of those, 304 were clinical trials or clinical studies. After abstract review, 23 trials were included in the review evaluating the following treatment modalities: pilocarpine (three); cevimeline (one); amifostine (eleven); submandibular gland transfer (five); acupuncture like transcutaneous electrical nerve stimulation (ALTENS) (one); hyperbaric oxygen (one); and acupuncture (one). Pilocarpine, cevimeline, and amifostine have been shown in some studies to improve xerostomia outcomes, at the cost of toxicity. ALTENS has similar efficacy with fewer side effects. Submandibular gland transfer is effective but requires an elective surgery, and thus may not always be appropriate or practical. The use of intensity-modulated radiation therapy, in addition to dose de-escalation in select patients, may result in fewer patients with late xerostomia, reducing the need for additional interventions.

Submandibular gland invasion and feasibility of gland-sparing neck dissection in oral cavity carcinoma

OBJECTIVE

This study investigated the incidence and routes of submandibular gland involvement in oral cavity carcinoma to determine the feasibility of submandibular gland sparing neck dissection.

METHODS

The records of 155 patients diagnosed with oral cavity squamous cell carcinoma, with a total of 183 neck specimens, including those involving level I, were reviewed retrospectively.

RESULTS

Submandibular gland involvement, via direct invasion from the anatomical proximity of T4a tumours, was evident in two patients. The floor of mouth location, either primarily or as an extension of the primary tumour, was the only risk factor for submandibular gland involvement in oral cavity carcinoma (p = 0.042). Tumour location, clinical and pathological tumour (T) and nodal (N) stages, and radiological suspicion of mandible invasion, were not found to be statistically relevant (p > 0.05).

CONCLUSION

The results suggest the feasibility of preserving the submandibular gland in early stage oral cavity carcinoma unless the tumour is located in, or extends to, the floor of mouth.

Structured review of the patient-reported outcome instruments used in clinical trials in head and neck surgery

The number of clinical trials that relate to patients with cancer of the head and neck is growing. Patient-reported outcomes, which are rarely the primary outcome, are now an important component, and in this structured review to identify and report the characteristics of the questionnaires that have been used in these trials, we summarise the findings reported. We searched several online databases using the key terms: head and neck oncology, head and neck surgery, reconstruction, clinical trials patient-reported outcomes, questionnaires, quality of life (QoL), validated instruments, and patients' satisfaction. We screened 1342 papers to collect information about the topic of the paper, sample size, selection criteria, main advantages and disadvantages of the patient-reported outcome used, and if it was used in conjunction with another measure. A total of 54 were eligible, and from them we identified 22 questionnaires. The primary reason for using a questionnaire was its relevance to the focus of the paper, such as xerostomia, pain, or swallowing. To allow the experience of patients to be the focus of the primary outcome in a clinical trial, we recommend that the measures used should be appropriate, reliable, valid, responsive, precise, interpretable, acceptable, and feasible. The trials used validated questionnaires, but the patient-reported outcome measures tended not to be the focus. There is merit in such measures being the primary outcomes in future trials and these should be designed around an explicit hypothesis.

Role of glial-cell-derived neurotrophic factor in salivary gland stem cell response to irradiation

BACKGROUND AND PURPOSE

Recently, stem cell therapy has been proposed to allow regeneration of radiation damaged salivary glands. It has been suggested that glial-cell-derived neurotrophic factor (GDNF) promotes survival of mice salivary gland stem cells (mSGSCs). The purpose of this study was to investigate the role of GDNF in the modulation of mSGSC response to irradiation and subsequent salivary gland regeneration.

METHODS

Salivary gland sphere derived cells of Gdnf hypermorphic (Gdnf^wt/hyper) and wild type mice (Gdnf^wt/wt) were irradiated (IR) with γ-rays at 0, 1, 2, 4 and 8Gy. mSGSC survival and stemness were assessed by calculating surviving fraction measured as post-IR sphere forming potential and population doublings. Flow cytometry was used to determine the CD24^hi/CD29^hi stem cell (SC) population. QPCR and immunofluorescence was used to detect GDNF expression.

RESULTS

The IR survival responses of mSGSCs were similar albeit resulted in larger spheres and an increased cell number in the Gdnf^wt/hyper compared to Gdnf^wt/wt group. Indeed, mSGSC of Gdnf^wt/hyper mice showed high sphere forming efficiency upon replating. Interestingly, GDNF expression co-localized with receptor tyrosine kinase (RET) and was upregulated after IR in vitro and in vivo, but normalized in vivo after mSGSC transplantation.

CONCLUSION

GDNF does not protect mSGSCs against irradiation but seems to promote mSGSCs proliferation through the GDNF-RET signaling pathway. Post-transplantation stimulation of GDNF/RET pathway may enhance the regenerative potential of mSGSCs.

Dental demineralization and caries in patients with head and neck cancer

Concurrent chemoradiation (CCR) therapy is a standard treatment for patients with locally advanced head and neck cancer (HNC). It is well documented that CCR causes profound acute and late toxicities. Xerostomia (the symptom of dry mouth) and hyposalivation (decreased salivary flow) are among the most common treatment side effects in this cohort of patients during and following treatment. They are the result of radiation-induced damage to the salivary glands. Patients with chronic hyposalivation are at risk for demineralization and dental cavitation (dental caries), often presenting as a severe form of rapidly developing decay that results in loss of dentition. Usual post-radiation oral care which includes the use of fluoride, may decrease, but does not eliminate dental caries associated with radiation-induced hyposalivation. The authors conducted a narrative literature review regarding dental caries in HNC population based on MEDLINE, PubMed, CLNAHL, Cochrane database, EMBASE, and PsycINFO from 1985 to 2014. Primary search terms included head and/or neck cancer, dental caries, dental decay, risk factor, physical symptom, physical sequellea, body image, quality of life, measurement, assessment, cost, prevention, and treatment. The authors also reviewed information from National Institute of Dental and Craniofacial Research (NIDCR), American Dental Association (ADA), and other related healthcare professional association web sites. This literature review focuses on critical issues related to dental caries in patients with HNC: potential mechanisms and contributing factors, clinical assessment, physical sequellea, negative impact on body image and quality of life, potential preventative strategies, and recommendations for practice and research in this area.

Safety of contralateral submandibular gland sparing in locally advanced oropharyngeal cancers: A multicenter review

BACKGROUND

Previous groups have shown contralateral submandibular gland sparing to improve xerostomia with safe outcomes, but primarily in early-stage disease. In this study, we present a large cohort of patients with locally advanced head and neck cancer that underwent contralateral submandibular gland-sparing radiotherapy, to demonstrate feasibility and safety specifically in patients with locally advanced disease.

METHODS

We retrospectively analyzed patients who were treated prospectively with contralateral submandibular gland sparing. Only patients who underwent bilateral neck radiotherapy with contralateral submandibular gland doses <39 Gy were included.

RESULTS

We identified 71 patients. Approximately 80% of patients had ≥N2b disease. The contralateral submandibular gland mean dose was 33 Gy and, at a median follow-up of 27.3 months, no patients experienced treatment failure in the contralateral level IB lymph nodes.

CONCLUSION

Xerostomia remains a significant morbidity despite parotid sparing and can be minimized further by contralateral submandibular gland sparing. These data provide important preliminary evidence that contralateral submandibular gland sparing is feasible and may be safe even in locally advanced cancers.

Double blind randomized prospective trial of bethanechol in the prevention of radiation-induced salivary gland dysfunction in head and neck cancer patients

This study assessed the prophylactic bethanechol use to prevent salivary gland dysfunction during radiotherapy. A total of 97 head and neck cancer patients were allocated into two groups: Bethanechol or Placebo. Bethanechol group presented significantly improve of salivary parameters. Bethanechol was effective in decreasing the salivary gland damage.

Salivary Secretory Disorders, Inducing Drugs, and Clinical Management

BACKGROUND

Salivary secretory disorders can be the result of a wide range of factors. Their prevalence and negative effects on the patient's quality of life oblige the clinician to confront the issue.

AIM

To review the salivary secretory disorders, inducing drugs and their clinical management.

METHODS

In this article, a literature search of these dysfunctions was conducted with the assistance of a research librarian in the MEDLINE/PubMed Database.

RESULTS

Xerostomia, or dry mouth syndrome, can be caused by medication, systemic diseases such as Sjögren's Syndrome, glandular pathologies, and radiotherapy of the head and neck. Treatment of dry mouth is aimed at both minimizing its symptoms and preventing oral complications with the employment of sialogogues and topical acting substances. Sialorrhea and drooling, are mainly due to medication or neurological systemic disease. There are various therapeutic, pharmacologic, and surgical alternatives for its management. The pharmacology of most of the substances employed for the treatment of salivary disorders is well-known. Nevertheless, in some cases a significant improvement in salivary function has not been observed after their administration.

CONCLUSION

At present, there are numerous frequently prescribed drugs whose unwanted effects include some kind of salivary disorder. In addition, the differing pathologic mechanisms, and the great variety of existing treatments hinder the clinical management of these patients. The authors have designed an algorithm to facilitate the decision making process when physicians, oral surgeons, or dentists face these salivary dysfunctions.

Submandibular Gland Transfer for the Prevention of Postradiation Xerostomia in Patients with Head and Neck Cancer: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Submandibular gland transfer has been widely used to prevent postradiation xerostomia in head-and-neck cancers. However, there are still some controversies. <b><i>Methods:</i></b> Six databases were searched, data extraction was performed and the risk of bias was assessed by 2 reviewers independently. The meta-analysis was performed using Review Manager, version 5.2. <b><i>Results:</i></b> A total of 7 trials (12 articles) and 369 participants were included. <b><i>Conclusions:</i></b> The present clinical evidence suggests that submandibular gland transfer might be highly effective to prevent postradiation xerostomia in head-and-neck cancers without serious adverse events. However, more randomized controlled trials are still needed to confirm this conclusion.

Wetting the whistle: neurotropic factor improves salivary function

Xerostomia, or dry mouth, is a common side effect of head and neck radiotherapy, Sjögren syndrome, diabetes, old age, and numerous medications. In this issue of the JCI, Xiao and colleagues identified glial cell line-derived neurotrophic factor (GDNF) as a potential stimulus for salivary stem cell growth. Due to its ability to promote neuronal growth, differentiation, and survival, GDNF is currently being used in clinical trials as a treatment for Parkinson disease; therefore, the findings of Xiao and colleagues may initiate a potential treatment for the millions of patients who suffer from xerostomia each year.

AdLTR2EF1α-FGF2-mediated prevention of fractionated irradiation-induced salivary hypofunction in swine

Patients frequently experience a loss of salivary function following irradiation (IR) for the treatment of an oral cavity and oropharyngeal cancer. Herein, we tested if transfer of fibroblast growth factor-2 (FGF2) cDNA could limit salivary dysfunction after fractionated IR (7.5 or 9 Gy for 5 consecutive days to one parotid gland) in the miniature pig (minipig). Parotid salivary flow rates steadily decreased by 16 weeks post-IR, whereas blood flow in the targeted parotid gland began to decrease ~3 days after beginning IR. By 2 weeks, post-IR salivary blood flow was reduced by 50%, at which point it remained stable for the remainder of the study. The single preadministration of a hybrid serotype 5 adenoviral vector encoding FGF2 (AdLTR2EF1a-FGF2) resulted in the protection of parotid microvascular endothelial cells from IR damage and significantly limited the decline of parotid salivary flow. Our results suggest that a local treatment directed at protecting salivary gland endothelial cells may be beneficial for patients undergoing IR for oral cavity and oropharyngeal cancer.

A risk score model for the metastasis of level Ib lymph node based on the clinicopathological features of nasopharyngeal carcinoma in a large sample

The aim of the present study was to develop a metastatic risk score model of neck level Ib lymph nodes in primary nasopharyngeal carcinoma (NPC) to guide the level Ib radiotherapy. There were a total of 1,557 patients enrolled in the study, and of these patients, 1,145 were included in the training set. Univariate χ² analysis and multivariate logistic regression analyses were used to screen the independent risk factors to construct the risk score model. A total of 85 patients in the validating set underwent a pathology biopsy of level Ib lymph nodes to test the model. The remaining 327 patients from the prognostic-research set were used to evaluate the prognostic impact of level Ib irradiation in high- and low-risk groups. The independent risk factors in the model were carotid sheath involvement, the maximal diameter of the neck lymph nodes (≥20 mm) and the involvement of the level II/III/IV lymph nodes. The involvement of level IV was assigned score 2 and the other risk factors were assigned score 1. According to the total scores, the patients were divided into the low- (total score, 0-1; level Ib metastasis rate, 0.5%) and high-risk groups (total score, 2-4; level Ib metastasis rate, 8.5%). In the validating set, the metastatic rate of level Ib in 43 low-risk patients was 0%, and the rate was 31.0% (13/42) in 42 high-risk patients. In the prognostic-research set, the prognosis of 137 low-risk patients was not affected by level Ib irradiation. However, level Ib unirradiation was an independent prognostic factor for the locoregional recurrence in 190 high-risk patients. According to the data, the novel score model could help assess the metastatic risk of level Ib in primary NPC, and the radiotherapy on level Ib may impact the locoregional recurrence in high-risk patients.

Management of radiotherapy-induced salivary hypofunction and consequent xerostomia in patients with oral or head and neck cancer: meta-analysis and literature review

OBJECTIVE

To analyze the efficacy of various treatment options for radiation-induced hyposalivation in patients with head and neck cancer.

STUDY DESIGN

A literature review and meta-analysis was performed on all appropriate literature identified via MEDLINE/PubMed.

RESULTS

Fourteen articles were identified that met inclusion criteria for review, and 8 articles qualified for inclusion in the meta-analysis. The available literature addressed both objective and subjective responses of hyposalivation, xerostomia, or both to cholinergic agonists (such as pilocarpine and cevimeline), salivary substitutes, hyperbaric oxygen, and acupuncture.

CONCLUSIONS

This analysis indicated that cholinergic agonists were more effective in treating radiation-induced hyposalivation compared with salivary substitutes, hyperbaric oxygen, and acupuncture. However, other treatment modalities, such as salivary substitutes and hyperbaric oxygen, were also found to subjectively improve patients' perception of xerostomia.

Late oral complications following radiotherapy for head and neck cancers

Radiotherapy is an important treatment modality for head and neck cancers, both as definitive treatment and as adjunct treatment after surgery. Complications are common after radiotherapy for head and neck cancer owing to irradiation of many normal tissues and structures with important functions related to daily activities. Of these, late oral complications are of particular concern because of their effect on many basic functions, such as speech and swallowing. Although late complications following radiotherapy have been recognized for many years, recent developments in the treatment of head and neck cancers may have a significant impact on the incidence and severity of late complications. This article examines the current issue of late oral complications after radiotherapy, with an emphasis on the impact of recent advances in cancer treatment.

Oral complications of cancer and cancer therapy: from cancer treatment to survivorship

Answer questions and earn CME/CNE Oral complications resulting from cancer and cancer therapies cause acute and late toxicities that may be underreported, underrecognized, and undertreated. Recent advances in cancer treatment have led to changes in the incidence, nature, and severity of oral complications. As the number of survivors increases, it is becoming increasingly recognized that the aggressive management of oral toxicities is needed to ensure optimal long-term oral health and general well-being. Advances in care have had an impact on previously recognized oral complications and are leading to newly recognized adverse effects. Here, the authors briefly review advances in cancer therapy, including recent advances in surgery, oral care, radiation therapy, hematopoietic cell transplantation, and medical oncology; describe how these advances affect oral health; and discuss the frequent and/or severe oral health complications associated with cancer and cancer treatment and their effect upon long-term health. Although some of the acute oral toxicities of cancer therapies may be reduced, they remain essentially unavoidable. The significant impact of long-term complications requires increased awareness and recognition to promote prevention and appropriate intervention. It is therefore important for the primary oncologist to be aware of these complications so that appropriate measures can be implemented in a timely manner. Prevention and management is best provided via multidisciplinary health care teams, which must be integrated and communicate effectively in order to provide the best patient care in a coordinated manner at the appropriate time.

Radiotherapy for head and neck cancer

Treatment for patients with head and neck cancer requires a multidisciplinary approach. Radiotherapy is employed as a primary treatment or as an adjuvant to surgery. Each specific subsite dictates the appropriate radiotherapy techniques, fields, dose, and fractionation scheme. Quality of life is also an important issue in the management of head and neck cancer. The radiation-related complications have a tremendous impact on the quality of life. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and image-guided radiotherapy, can offer precise radiation delivery and reduce the dose to the surrounding normal tissues without compromise of target coverage. In the future, efforts should be made in the exploration of novel strategies to improve treatment outcome in patients with head and neck cancer.

The Preventive and Therapeutic Effect of Acupuncture for Radiation-Induced Xerostomia in Patients With Head and Neck Cancer

Background. Methods currently available to prevent and manage xerostomia which caused by radiotherapy in patients with head and neck caner have limited efficacy. Some studies suggest that acupuncture may be beneficial. Objectives. The authors evaluated the preventive and therapeutic effect of acupuncture for radiation-induced xerostomia among patients with head and neck cancer. Methods. PUBMED, EMBASE, Cochrane Library, CBM, CAJD, Wan Fang database, and VIP Database for Chinese Technical Periodicals were electronically searched, in conjunction with further manual search for relevant articles. Studies that met the inclusion criteria were systematically evaluated. Results. Three randomized controlled trials (RCTs) investigating the therapeutic effect of acupuncture were included. One RCT on the preventive effect of acupuncture was found. Because of the considerable variation among included studies, meta-analysis was not possible. Two included RCTs used placebo controls, and both observed significant improvement in the salivary flow rates between acupuncture and control groups. However, no significant differences were found. Three included RCTs suggested that acupuncture for radiation-induced xerostomia can improve patients’ subjective symptoms. The only study evaluating the preventive effect of acupuncture for radiation-induced xerostomia showed positive changes in salivary flow rates (both unstimulated and stimulated) and dry mouth -related symptoms. Acupuncture treatment was well tolerated by all patients and no severe adverse effects were seen. Conclusions. Insufficient evidence is available to judge whether acupuncture is safe and whether it is effective in preventing or treating radiation-induced xerostomia. Significant research remains to be done before acupuncture can be recommended for routine use in radiation-induced xerostomia.

Submandibular gland-sparing intensity modulated radiotherapy in the treatment of head and neck cancer: sites of locoregional relapse and survival

BACKGROUND AND PURPOSE

To evaluate the patterns of locoregional relapse and survival following submandibular gland (SMG)-sparing intensity modulated radiotherapy (IMRT).

PATIENTS AND METHODS

Eighty patients with laryngeal (n = 15), oropharyngeal (n = 50), hypopharyngeal (n = 11) or nasopharyngeal cancer (n = 4) were treated by submandibular gland-sparing IMRT for head and neck squamous cell cancer between July 2000 and December 2008. All patients were treated by bilateral IMRT. Thirty-nine (49%) received definitive radiotherapy (RT) and 41 (51%) postoperative RT. The contralateral parotid gland (PG) and SMG were included in the dose optimization planning program with intent to keep the mean doses for PG and SMG below 23 Gy and 28-30 Gy, respectively. The ipsilateral glands were also spared when considered feasible.

RESULTS

During a median follow-up time of 51 months (range, 24-117 months) nine local recurrent tumors were observed. Four of these nine patients were salvaged by surgery with no further recurrence. All local recurrences were located within the high-dose CTVs. None of the locally recurrent cancers were located at the vicinity of the spared PGs or SMGs. No recurrent tumors were observed in the contralateral neck. The Kaplan-Meier estimate for local control at five years following IMRT was 88% for the whole cohort and the corresponding figure for local control following salvage surgery was 94%. The estimates for five-year overall survival and disease-specific survival were 85% and 90%, respectively.

CONCLUSION

In selected head and neck cancer patients who are estimated to have a low risk of cancer recurrence at the nodal levels I-II and who are treated with SMG-sparing IMRT the risk of cancer recurrence at the vicinity of the spared salivary glands is low.

Salivary gland sparing in the treatment of head and neck cancer

Radiotherapy is an important component of the multimodality treatment of head and neck cancer. Although an effective treatment for many patients, it can have significant long-term sequelae. In particular, xerostomia - or dry mouth - caused by salivary gland injury is a serious problem suffered by most patients and leads to problems with oral comfort, dental health, speech and swallowing. This article explores the mechanisms behind radiation injury to the major salivary glands, as well as different strategies to minimize and alleviate xerostomia. This includes technical approaches to minimize radiation dose to salivary tissue, such as intensity-modulated radiotherapy and surgical transfer of salivary glands, as well as pharmacologic approaches to stimulate or protect the salivary tissue. The scientific literature will be critically examined to see what works and what strategies have been less effective in attempting to minimize xerostomia in head and neck cancer patients.

Submandibular salivary gland transfer for the prevention of radiation-induced xerostomia in patients with nasopharyngeal carcinoma: 5-Year outcomes

BACKGROUND

Our aim in this study was to investigate the value of the submandibular salivary gland transfer procedure in prevention of radiation-induced xerostomia in patients with nasopharyngeal carcinoma (NPC).

METHODS

In all, there were 70 patients, consisting of a test group (36 patients) and a control group (34 patients) in a nonrandomized fashion. In the test group, the submandibular salivary gland was transferred to submental space before radiotherapy (XRT) and shielded. Salivary gland functions were evaluated by the amount of saliva and a quality of life questionnaire before and after XRT and 3 and 60 months after XRT.

RESULTS

At 5 years, the trapping and excretion functions of salivary gland were significantly better in the test group (p = .000 and p = .000). The mean weight of saliva after XRT was heavier (1.65 g vs 0.73 g, p = .000), and the incidence of xerostomia was lower in the test group, with no difference in 5-year survival and neck nodal recurrence between the 2 groups.

CONCLUSIONS

Salivary gland transfer procedure prevents XRT-induced xerostomia and improves quality of life of patients with NPC.

Sparing the contralateral submandibular gland without compromising PTV coverage by using volumetric modulated arc therapy

BACKGROUND

Salivary gland function decreases after radiation doses of 39 Gy or higher. Currently, submandibular glands are not routinely spared. We implemented a technique for sparing contralateral submandibular glands (CLSM) during contralateral elective neck irradiation without compromising PTV coverage.

METHODS

Volumetric modulated arc therapy (RapidArc™) plans were applied in 31 patients with stage II-IV HNC without contralateral neck metastases, all of whom received elective treatment to contralateral nodal levels II-IV. Group 1 consisted of 21 patients undergoing concurrent chemo-radiotherapy, with elective nodal doses of 57.75 Gy (PTVelect) and 70 Gy to tumor and pathological nodes (PTVboost) in 7 weeks. Group 2 consisted of 10 patients treated with radiotherapy to 54.45 Gy to PTVelect and 70 Gy to PTVboost in 6 weeks. All clinical plans spared the CLSM using individually adapted constraints. For each patient, a second plan was retrospectively generated without CLSM constraints ('non-sparing plan').

RESULTS

PTV coverage was similar for both plans, with 98.7% of PTVelect and 99.2% of PTVboost receiving ≥95% of the prescription dose. The mean CLSM dose in group 1 was 33.2 Gy for clinical plans, versus 50.6 Gy in 'non-sparing plans' (p < 0.001). In group 2, mean CLSM dose was 34.4 Gy for clinical plans, and 46.8 Gy for non-sparing plans (p = 0.002).

CONCLUSIONS

Elective radiotherapy to contralateral nodal levels II-IV using RapidArc consistently limited CLSM doses well below 39 Gy, without compromising PTV-coverage. Future studies will reveal if this extent of dose reduction can reduce patient symptoms.

Is it oncologically safe to leave the ipsilateral submandibular gland during neck dissection for head and neck squamous cell carcinoma?

Aim:

To investigate the incidence of metastasis to the submandibular gland in patients with head and neck squamous cell carcinoma.

Methods:

We retrospectively evaluated histological reports of neck dissections for upper respiratory tract carcinoma (performed 2002–2009), recording: primary tumour site, tumour–node–metastasis stage, level Ib involvement, previous radiotherapy, perineural invasion, lymphovascular invasion, extracapsular spread, and the presence of malignant disease in the submandibular gland.

Results:

We evaluated 107 cases. The most common primary site was the oral cavity (49 per cent) followed by the supraglottis (21 per cent), glottis (14 per cent), oropharynx (9 per cent) and hypopharynx (6 per cent). Forty-eight per cent of patients had advanced local disease, with 21 per cent at tumour stage 3 and 27 per cent at tumour stage 4. Fifty-six per cent had cervical lymph node metastasis, and 8 per cent received pre-operative radiotherapy. Forty-eight per cent had perineural invasion, 46 per cent lymphovascular spread, 27 per cent extracapsular spread and 8 per cent level Ib metastasis. Only one patient had submandibular gland involvement, due to direct spread (a case with prior radiotherapy and macroscopic submandibular gland involvement evident peri-operatively).

Conclusion:

Submandibular gland metastasis from head and neck primary squamous cell carcinoma is extremely rare. Preservation of the ipsilateral submandibular gland during neck dissection is oncologically safe, except in patients with prior surgery or radiotherapy, or a primary tumour in close relation to the gland.

Functional outcomes related to the prevention of radiation-induced xerostomia: oral pilocarpine versus submandibular salivary gland transfer

BACKGROUND

Xerostomia has a devastating impact on oral function and quality of life in patients who receive radiation treatment for head and neck cancer. The purpose of this study was to examine functional outcomes related to 2 saliva-sparing treatments: (1) oral pilocarpine during radiotherapy; or (2) the submandibular salivary gland transfer (SGT) before radiotherapy.

METHODS

Sixty-nine patients were recruited (SGT = 36; pilocarpine = 33). Speech intelligibility, swallowing outcomes, and quality of life were assessed at 4 points in time (pretreatment, and 1 month, 6 months, and 12 months after the pretreatment assessment).

RESULTS

There were no differences between groups in speech outcomes; however, significant between-group differences existed in swallowing and quality of life outcomes. In all cases, patients who received the SGT procedure had better swallowing outcomes and quality of life scores than the patients who received oral pilocarpine.

CONCLUSION

The SGT should be the treatment of choice between the 2 treatments offered to prevent xerostomia in the present study.

A systematic review of salivary gland hypofunction and xerostomia induced by cancer therapies: management strategies and economic impact

PURPOSE

This systematic review aimed to assess the literature for management strategies and economic impact of salivary gland hypofunction and xerostomia induced by cancer therapies and to determine the quality of evidence-based management recommendations.

METHODS

The electronic databases of MEDLINE/PubMed and EMBASE were searched for articles published in English since the 1989 NIH Development Consensus Conference on the Oral Complications of Cancer Therapies until 2008 inclusive. For each article, two independent reviewers extracted information regarding study design, study population, interventions, outcome measures, results, and conclusions.

RESULTS

Seventy-two interventional studies met the inclusion criteria. In addition, 49 intensity-modulated radiation therapy (IMRT) studies were included as a management strategy aiming for less salivary gland damage. Management guideline recommendations were drawn up for IMRT, amifostine, muscarinic agonist stimulation, oral mucosal lubricants, acupuncture, and submandibular gland transfer.

CONCLUSIONS

There is evidence that salivary gland hypofunction and xerostomia induced by cancer therapies can be prevented or symptoms be minimized to some degree, depending on the type of cancer treatment. Management guideline recommendations are provided for IMRT, amifostine, muscarinic agonist stimulation, oral mucosal lubricants, acupuncture, and submandibular gland transfer. Fields of sparse literature identified included effects of gustatory and masticatory stimulation, specific oral mucosal lubricant formulas, submandibular gland transfer, acupuncture, hyperbaric oxygen treatment, management strategies in pediatric cancer populations, and the economic consequences of salivary gland hypofunction and xerostomia.

Sparing the parotid glands and surgically transferred submandibular gland with helical tomotherapy in post-operative radiation of head and neck cancer: a planning study

BACKGROUND AND PURPOSE

To evaluate the feasibility of sparing the parotid glands and surgically transferred submandibular gland (SMG) by intensity modulated radiotherapy (IMRT) in post-operative cases of head and neck cancer (HNC).

MATERIALS AND METHODS

Ten patients (larynx-2, base of tongue-4, tonsil-3, and unknown primary-1; pathologic stages III-IV) who underwent SMG transfers on the side of N0 neck along with definitive surgery were selected for this study. IMRT planning was done retrospectively using helical tomotherapy approach. Planning objective was to deliver 60 Gy to PTV1 and 54 Gy to PTV2 while maintaining the mean dose to the total parotid volume (TPV) and SMG less than 26 Gy.

RESULTS

The mean dose (+/-SD) to the TPV and SMG were 25+/-0.6 Gy and 23+/-1.9 Gy, respectively. The D(95) for PTV1 and PTV2 were 59.9+/-0.1 Gy and 54.9+/-0.3 Gy, respectively, satisfying our planning goal for PTV coverage. The D(99) for PTV1 and PTV2 were 58.2+/-0.7 Gy and 49.5+/-2.2 Gy, respectively, showing that sparing the salivary glands did not result in underdosing of the PTVs.

CONCLUSIONS

By combining the gland transfer and IMRT, the mean dose to TPV and transferred SMG could be reduced to less than 26 Gy in post-operative patients of HNC.

[Cell-based strategies for salivary gland regeneration]

Xerostomia as a side effect of radiotherapy or due to Sjögren's disease leads to considerable impairment of the quality of life of the affected patients. Preventive treatment approaches such as intensity-modulated radiotherapy, surgical transfer of a submandibular gland to a site outside the radiation field or administration of amifostin during radiation treatment are not yet completely established in clinical practice and are not applicable for all patients. Symptomatic treatment with pilocarpin or synthetic saliva leads to an improvement of the symptoms only in some patients, and in the case of pilocarpin significant systemic anticholinergic side-effects might occur. Because large numbers of patients are affected and current treatment options are not satisfactory, it is essential to develop new treatment options. In parallel with the in vitro production of functional salivary gland constructs by means of tissue engineering techniques, attempts are currently under way to experimentally restore salivary gland function by genetic treatment approaches such as transfection of the affected salivary glands with aquaporins or pro-angiogenic factors. In addition, the in vivo application of stem cells is under investigation. In the present paper, we discuss the clinical and radiobiological background of xerostomia and highlight possible innovative future treatment options.