Preliminary observations on the effect of mantle field radiotherapy on salivary flow rates in patients with Hodgkin's disease

Surgery of the major salivary glands and its impact on salivary flow-A review

OBJECTIVE

The aim of this study was to bring attention to a rather unnoted side effect of salivary gland surgery-reduced salivary flow.

METHODS

A systematic PubMed, Cochrane Library, LIVIVO, and Embase databases search was performed to identify relevant articles.

RESULTS

Eight studies matched the inclusion criteria. All studies described an association between salivary gland surgery and reduced salivary flow. In five of the eight studies, patients reported on xerostomia after salivary gland surgery.

CONCLUSIONS

Head and neck surgeons should inform their patients more accurately about reduced salivary flow and possible xerostomia after salivary gland surgery, and focus more on conservative strategies and minimally invasive techniques. Laryngoscope, 129:2053-2058, 2019.

A prospective study of salivary gland function in lymphoma patients receiving head and neck irradiation

PURPOSE

To determine the radiation dose-response relationship on salivary dysfunction and quality of life (QOL) over time in patients with lymphoma receiving radiation therapy (RT) to the head and neck (H&N).

METHODS AND MATERIALS

We conducted a prospective study on salivary-gland function in lymphoma patients receiving RT to the H&N. Fifteen patients were enrolled on the study. Dose-volume histograms and mean doses to the salivary glands were generated. Radiation-related toxicities and H&N-specific QOL were assessed before treatment and at prespecified time points posttreatment. Factors predicting a decrement in QOL were explored using Fisher's exact test.

RESULTS

During RT, 47% of patients experienced Grade >or= 2 acute toxicity of the salivary gland, mucous membrane, or both. QOL scores improved over time, but up to one third of patients continued to have persistent oral symptoms at 2 years. At 6 months, a mean dose to at least one of the parotids of > 31 Gy was significantly associated with persistent dry mouth (100% vs. 17%, p = 0.02) and sticky saliva (100% vs. 25%, p = 0.04); a mean dose of > 11 Gy to the minor salivary glands was significantly associated with persistent sticky saliva (100% vs. 25%, p = 0.04), although the difference was no longer significant at 1 year.

CONCLUSIONS

Limiting the mean parotid dose to <or= 31 Gy and mean minor salivary gland dose to <or= 11 Gy in lymphoma patients treated to the H&N may help reduce the risk of subacute xerostomia.

Salivary flow rates measured during radiation therapy in head and neck cancer patients: a pilot study assessing salivary sediment formation

STATEMENT OF PROBLEM

Xerostomia often occurs in patients being managed for head and neck cancer who receive radiation therapy. Although accurate salivary sampling can be therapeutically important to measure during radiation, sampling errors can occur because of salivary sediments. Determining the impact that salivary sediments have on measured salivary flow rates during radiation is important for management of patients.

PURPOSE

The purpose of this study was to assess the magnitude of error associated with the inclusion of nonsalivary components (sediment) in the calculation of whole stimulated saliva flow rates prior to and during radiation therapy (SS and SSR) in patients with head and neck cancer.

MATERIAL AND METHODS

Whole paraffin-stimulated saliva was collected in large-mouth centrifuge tubes from 20 patients with head and neck cancer prior to and during the third week of radiation therapy. Gravimetric methods were used to calculate the flow rates at g/5 min. After centrifugation, supernatant saliva was removed and the sediment was oven-dried to remove residual moisture. Sediment weight was subtracted from the original weight of saliva specimens and flow rates were recalculated. Means and standard deviations were determined and flow rate differences before (BC) and after (AC) sediment correction were evaluated statistically with the paired t test (alpha=.05). A nonparametric analysis of the flow rate data with the Wilcoxon matched-pairs signed-ranks test was also used to examine the magnitude and direction of the intrapair (BC-AC) differences (alpha=.05).

RESULTS

On average, salivary sediment contributed less than 1% of the total uncorrected weight of saliva prior to radiation therapy. In specimens collected during radiation therapy, sediment contributed an average of 14% of the total uncorrected weight and as high as 95.4% in 1 patient. Sediment percentages were 20% and higher in 4 patients. In the Wilcoxon analysis, 19 out of 20 paired BC and AC flow rates were higher in the BC group in the SS and SSR samples.

CONCLUSIONS

The error associated with the inclusion of salivary sediment in the calculation of saliva flow rates prior to radiation treatment was small, but statistically significant. The magnitude of the sediment effect was more pronounced in specimens taken during radiotherapy and was significant, as determined by the Wilcoxon test, but the mean paired differences were not significantly different according to the t test.

A randomized phase II trial of amifostine for head and neck irradiation in lymphoma

Acute and long-term oral complications occur in patients receiving mantle radiation therapy or irradiation to the head and neck region for Hodgkin's disease or non-Hodgkin's lymphoma. While considerable data are available on the effect of radiation therapy on the oral function and quality of life of patients with squamous cell carcinoma of the head and neck, such information is lacking for similarly irradiated lymphoma patients. In this article we discuss the rationale and study design of an ongoing, randomized phase II study evaluating the role of amifostine (Ethyol; Medimmune Inc, Gaithersburg, MD) as a radiation protectant in patients receiving head and neck irradiation for lymphoma. Further investigation in this lymphoma population is needed to improve our understanding of the extent of the problem and its impact on patients' daily living and functioning. Importantly, fine-tuning the treatment and management approaches to minimize morbidity while maximizing the survival and quality of life of patients are crucial next steps.

Mutans streptococci in xerostomic cancer patients after pilocarpine therapy: A pilot study

OBJECTIVES

Opiod- and/or radiation-induced xerostomia in cancer patients is frequently associated with elevated levels of cariogenic mutans streptococci (MS).

STUDY DESIGN

In a single-center, single blind 8-week clinical trial at The University of Texas M. D. Anderson Cancer Center, and from an initial sample of 32 patients, we evaluated MS counts in 28 cancer patients receiving chronic analgesic treatment for cancer pain. All patients received escalating doses of pilocarpine (Salagen) tablets, either 2.5 mg to 5 mg or 5 mg to 7.5 mg qid for 6 weeks, followed by placebo qid for a 2-week washout period. Whole resting saliva flow rates (g/5 min) and MS counts were evaluated at pretreatment, 3 weeks, 6 weeks, and 8 weeks. MS samples were obtained by 5-mL saline rinse (15 sec) at each visit prior to sialometry.

RESULTS

In 19 patients (59%), MS counts exceeded 10(5) CFU/mL. At the end of the 6-week trial, 96% of patients showed a positive response to pilocarpine following a 30-minute postdosing evaluation (P=.001). MS counts were lower in 17 patients, higher in 6 patients, and nondetectable before and after pilocarpine in 5 patients (P=.03).

CONCLUSION

The reduced MS counts associated with improved saliva flow rates following pilocarpine therapy in this short-term pilot study are encouraging, but further investigation in a larger group of patients over a longer study period is indicated.

Effect of Radiotherapy on the Levels of Secretory Immunoglobulin A Against Indigenous and Virulent Streptococci

If is well known that the frequency of upper respiratory infection is clinically increased after radiotherapy of the head and neck region. This study found higher antibacterial secretory immunoglobulin A (S-IgA) activity against three indigenous streptococci ( Streptococcus mitis, S. salivarius, and S. sanguis I) and S. pneumoniae in patients who had undergone radiation therapy of the head and neck region than in control subjects. This showed no relation to the extent of the radiation field. Compared with before radiotherapy, the S-IgA titer against S. pneumoniae and its ratio to the activities against the indigenous streptococci were significantly higher in patients with fully irradiated major salivary glands. These results indicated that the radiotherapy promoted the antigen-specific S-IgA production of virulent streptococci in most patients with head and neck cancer, even more than 6 months after radiotherapy. The resulting altered balance in the S-IgA system of normal indigenous streptococci may also impair the ability to maintain the stable bacterial interference between normal indigenous and virulent streptococci in the oropharyngeal cavity.

Oral health care for the cancer patient

Orofacial complications are common after radiotherapy to the head and neck, and after chemotherapy for malignant disease. Mucositis is the most frequent and often most distressing complication, but adverse reactions can affect all other orofacial tissues. This paper discusses the aetiopathogenesis and current means available for preventing, ameliorating and treating these complications, as well as indicating research directions.

Whole salivary flow rates following submandibular gland resection

BACKGROUND

Patients with head and neck neoplasms receive therapeutic neck dissections which may include the submandibular gland unilaterally or bilaterally. The clinical consequences of salivary gland resection could be reduced salivary output, altered cariogenic microflora, and increased incidence of dental caries.

METHODS

This investigation evaluated whole salivary flow rates of patients who had received unilateral (n = 29) or bilateral (n = 8) submandibular gland resections and compared them with noncancer control subjects (n = 29).

RESULTS

Unstimulated and stimulated (paraffin) flow rates were significantly lower in both resection groups compared with those of the noncancer group, ranging from p < .002 to p < .02. Although flow rates were lower in the bilateral group than in the unilateral group, the differences between these two groups were statistically significant (p < .02) only for stimulated saliva. Xerostomia was reported by one third of the resection subjects.

CONCLUSION

In view of the significantly lower flow rates observed in the resection groups (especially for unstimulated saliva), topical fluoride therapy should be considered for those patients whose past caries activity would indicate an increased caries risk associated with partial loss of salivary function.

Cariogenic microflora in patients with Hodgkin's disease before and after mantle field radiotherapy

Because mantle field radiotherapy is associated with partial xerostomia in patients with Hodgkin's disease, the purpose of this study was to evaluate their cariogenic microflora before and after completion of radiotherapy. We obtained samples of oral saline solution rinse from 40 patients with Hodgkin's disease before radiotherapy and from 31 patients with Hodgkin's disease who had survived 1 to 24 years after radiotherapy. We also evaluated caries experience and history of fluoride gel use for caries prevention in these patients. Mutans streptococci and lactobacilli levels were significantly higher in the postradiotherapy patients with carious teeth, particularly in those with limited home use of fluoride gels. In the postradiotherapy group, caries parameters were significantly higher (p < 0.05) than in the preradiotherapy group. Within the postradiotherapy group, both caries and microbial parameters tended to be higher in patients who were less compliant about using the recommended 0.4% stannous fluoride "brush-in" technique than in those who used the gel regularly at home. This study indicates that for patients with Hodgkin's disease who receive mantle field irradiation during the management of their disease, a sustained brush-in program with stannous fluoride gel can be of benefit for caries prevention and for limitation of oral levels of cariogenic mutans streptococci.

Late effects of head and neck radiation therapy and patient/dentist compliance with recommended dental care

Head and neck radiation therapy patients have permanent damage to their salivary glands, tissue, and bone. This damage may result in late effects such as: xerostomia, rampant dental caries, demineralization, trismus, and osteoradionecrosis. Therefore, a pretherapy dental evaluation and treatment and compliance with a long-term oral care regimen are necessary. This retrospective study was designed to assess the late effects of radiation therapy and compliance with long-term care recommendations of patients seen in the Oncology Dental Support Clinic at the University of Missouri-Kansas City School of Dentistry during 1981 to 1989. Telephone interviews of patients and their dentists were conducted, and a written questionnaire to the dentists provided further data. Late effects were consistent with those reported in the literature. A compliance rate of approximately 50% was reported. Several measures have been implemented in an attempt to increase compliance.

Obtaining pre-radiation therapy dental clearance

Patients scheduled to receive radiation therapy that involves the mandible, maxilla or salivary glands should be referred for dental consultation, assessment and clearance before therapy begins. A form that aids the radiation oncologist and the dentist in patient referrals is presented.

Effect of radioactive iodine therapy on salivary flow rates and oral Streptococcus mutans prevalence in patients with thyroid cancer

Unstimulated and stimulated salivary flow rates, Streptococcus mutans samples, and dental caries data were obtained from 50 patients with thyroid cancer who had received radioactive iodine, I131, from 0.3 to 20 years earlier. The salivary flow rates were compared with a healthy control group, and the S. mutans counts were compared to a group of patients with head and neck cancer who were sampled before radiotherapy. Flow rates were found to be significantly lower in the patients with thyroid cancer, and S. mutans levels were slightly but not significantly higher than the controls. Longitudinal flow rate data taken on four patients, who served as their own controls before and after I131 therapy, indicated a trend in saliva reduction.

Effects of total body irradiation on salivary gland function and caries-associated oral microflora in bone marrow transplant patients

Forty-one cancer patients who received chemoradiotherapy conditioning with bone marrow transplantation were examined for changes in salivary gland function and caries-associated oral microflora. Salivary flow rates (stimulated and unstimulated) and Streptococcus mutans levels decreased after pretransplant cytoreductive therapy and posttransplant prophylactic antibiotic therapy. Normal levels returned with time after the patients left the protected environment. Lactobacillus counts were not affected. Chronic graft-versus-host disease did not significantly influence saliva production. Results indicate that irradiation is probably the major factor responsible for the transient xerostomia.

Salivary flow rates in patients with head and neck cancer 0.5 to 25 years after radiotherapy

In this clinical study at the University of Texas M. D. Anderson Cancer Center, unstimulated and stimulated salivary flow rates were obtained from 47 patients with head and neck cancer who had received mantle, unilateral facial, or bilateral facial field radiotherapy from 0.5 to 25 years earlier. The magnitude of salivary flow rate reduction compared with a healthy control group was primarily related to the radiation dosage and the amount of salivary gland tissue included in the irradiated fields. Flow rates were lower for women in all groups, but these differences were not statistically significant.