Late effects of radiation therapy in the head and neck region

Aortotracheal Fistula Secondary to Bacterial Aortitis

Fistulas between the aorta and tracheobronchial tree are rare fatal complications that occur in patients treated with external and endobronchial radiation for carcinomas of the upper and lower respiratory tract. The etiopathogenesis can be multifactorial. We report the case of a patient with irradiated tracheal carcinoma who died of massive hemoptysis 25 months after completing therapy. Autopsy revealed a fistula between the trachea and arch of the aorta. Multiple colonies of cocci and bacilli were demonstrated within the media at the site of rupture and were absent in other areas of the aorta. The development of an aortotracheal fistula in this patient was most probably related to infection in an area of tracheal and vascular wall previously damaged by exposure to high doses of radiation.

Multicentric investigation of ionising radiation-induced cell death as a predictive parameter of individual radiosensitivity

In the present study, the predictive value of ionising radiation (IR)-induced cell death was tested in peripheral blood lymphocytes (PBLs) and their corresponding Epstein-Barr virus-transformed lymphoblastoid cell lines (LCLs) in an interlaboratory comparison. PBLs and their corresponding LCLs were derived from 15 tumour patients, that were considered clinically radiosensitive based on acute side-effects, and matched controls. Upon coding of the samples, radiosensitivity of the matched pairs was analysed in parallel in three different laboratories by assessing radiation-induced apoptotic and necrotic cell death using annexin V. All participating laboratories detected a dose-dependent increase of apoptosis and necrosis in the individual samples, to a very similar extent. However, comparing the mean values of apoptotic and necrotic levels derived from PBLs of the radiosensitive cohort with the mean values of the control cohort did not reveal a significant difference. Furthermore, within 15 matched pairs, no sample was unambiguously and independently identified by all three participating laboratories to demonstrate in vitro hypersensitivity that matched the clinical hypersensitivity. As has been reported previously, apoptotic and necrotic cell death is barely detectable in immortalised LCL derivatives using low doses of IR. Concomitantly, the differences in apoptosis or necrosis levels found in primary cells of different individuals were not observed in the corresponding LCL derivatives. All participating laboratories concordantly reasoned that, with the methods applied here, IR-induced cell death in PBLs is unsuitable to unequivocally predict the individual clinical radiosensitivity of cancer patients. Furthermore, LCLs do not reflect the physiological properties of the corresponding primary blood lymphocytes with regard to IR-induced cell death. Their value to predict clinical radiosensitivity is thus highly questionable.

Disorders of swallowing: palliative care

This article defines palliative care for swallowing disorders as treatment for severe and chronic dysphagia or intractable aspiration when the recovery of normal swallowing is not anticipated and attempts to restore normal swallowing have been unsuccessful. Palliative treatment for dysphagia is not only for the dying patient because patients with difficulty swallowing can live for a long time. Palliative care for dysphagia is aimed at maximizing swallowing function, maintaining pulmonary health, and supporting healthy nutrition despite the impaired ability to swallow. When despite all attempts at intervention a patient becomes totally unable to swallow, the goal of therapy changes toward finding ways to provide adequate nutrition for the patient.

Radiotherapy for the management of locally advanced squamous cell carcinoma of the head and neck

BACKGROUND

Squamous cell carcinomas of the head and neck (SCCHN) affect approximately 35 000 people in the United States yearly. Although survival has improved with advances in therapy, patients with advanced stages of SCCHN continue to have a poor prognosis. An understanding of rationale for treatment selection, newer developments in therapy, and treatment toxicity is critical.

METHODS

Standard methods of treating locally advanced SCCHN are reviewed. Advances in medical and radiotherapeutic management are discussed and the toxicities of therapy are described.

RESULTS

Postoperative chemoradiation is used in patients with high-risk characteristics. Induction chemotherapy and altered fractionation radiation treatment have been evaluated as alternatives to definitive chemo-radiotherapy. Targeted agents such as cetuximab may prove to increase survival with minimal increase in toxicity profile. Technological improvements such as the use of intensity-modulated radiation treatment have proven to decrease some debilitating side effects from radiation treatment.

CONCLUSIONS

Locally advanced SCCHN continues to present a therapeutic challenge. Survival, local control, and quality of life are all goals of treatment. The optimal method of treating locally advanced SCCHN is the subject of ongoing research. Long-term side effects can be minimized with the use of newer technologies and with careful treatment planning.

The effect of amifostine or IMRT to preserve the parotid function after radiotherapy of the head and neck region measured by quantitative salivary gland scintigraphy

PURPOSE

In this retrospective study, two approaches to preserve the parotid function after radiotherapy (RT) were compared: application of the radioprotective agent amifostine during RT and parotid-sparing intensity-modulated radiotherapy (IMRT).

PATIENTS AND METHODS

Patients were qualified for this analysis if (1) both parotid glands received a radiation dose of >or=50Gy using conventional radiotherapy techniques (cRT) or if they received a parotid-sparing IMRT as alternative, if (2) salivary gland scintigraphies before and after RT were performed, and if (3) a normal parotid function was present before RT. Quantitative salivary gland scintigraphy was used to assess the parotid gland function.

RESULTS

Altogether 275 salivary gland scintigraphies of 100 patients were analyzed. The mean relative tracer uptake (DeltaU) of patients treated with cRT, cRT with amifostine and IMRT 1-12 months after RT was 0.59 (95%CI 0.54-0.65), 0.67 (95%CI 0.59-0.76), and 0.93 (95%CI 0.78-1.07), respectively. The mean relative DeltaU 13-47 months after RT was 0.40 (95%CI 0.32-0.49), 0.60 (95%CI 0.48-0.71), and 0.92 (95%CI 0.56-1.28). At 1-12 months after RT, ANOVA testing with post-hoc comparison using the Bonferroni correction showed a significant difference between IMRT and cRT (p<0.001) or IMRT and amifostine (p<0.01). The difference between amifostine and cRT was not significant during the first year. At 13-47 months after RT, the difference between cRT and amifostine was significant (p=0.02).

CONCLUSION

Our data suggest that both amifostine and IMRT are able to partially preserve the parotid function after radiotherapy. The effect of IMRT appeared to be much greater.

Long-term prevalence of oropharyngeal dysphagia in head and neck cancer patients: Impact on quality of life

BACKGROUND & AIMS

To determine the prevalence of dysphagia in head and neck cancer patients treated with surgery and radiotherapy or chemoradiotherapy. To study the impact of dysphagia on food habits, nutritional status, and quality of life.

METHODS

Retrospective cross-sectional study of 87 head and neck cancer patients treated with surgery and radiotherapy or chemoradiotherapy from January 2000 through May 2005. Time since surgery was 28.5+/-17.8 months. A clinical test was used to detect dysphagia. A nutritional assessment was performed in all patients. A questionnaire was used to evaluate quality of life.

RESULTS

Oropharyngeal dysphagia was present in 50.6% of patients, mostly to solid foods (72.4%). Patients with total glossectomy and chemoradiotherapy had the highest rate of dysphagia. Nutritional support was necessary in 57.1% of patients. Malnutrition was present in 20.3% of patients, mainly marasmus (81%). Fifty-one percent of patients reported a decrease in their quality of life due to dysphagia.

CONCLUSIONS

We found a high prevalence of dysphagia in head and neck cancer patients treated with surgery and coadjuvant treatment. This problem negatively affects their quality of life. It is important that nutritional surveillance be provided to detect it and to prevent malnutrition.

Dynamic contrast-enhanced CT of head and neck tumors: perfusion measurements using a distributed-parameter tracer kinetic model. Initial results and comparison with deconvolution-based analysis

The objective of this work was to evaluate the feasibility of a two-compartment distributed-parameter (DP) tracer kinetic model to generate functional images of several physiologic parameters from dynamic contrast-enhanced CT data obtained of patients with extracranial head and neck tumors and to compare the DP functional images to those obtained by deconvolution-based DCE-CT data analysis. We performed post-processing of DCE-CT studies, obtained from 15 patients with benign and malignant head and neck cancer. We introduced a DP model of the impulse residue function for a capillary-tissue exchange unit, which accounts for the processes of convective transport and capillary-tissue exchange. The calculated parametric maps represented blood flow (F), intravascular blood volume (v(1)), extravascular extracellular blood volume (v(2)), vascular transit time (t(1)), permeability-surface area product (PS), transfer ratios k(12) and k(21), and the fraction of extracted tracer (E). Based on the same regions of interest (ROI) analysis, we calculated the tumor blood flow (BF), blood volume (BV) and mean transit time (MTT) by using a modified deconvolution-based analysis taking into account the extravasation of the contrast agent for PS imaging. We compared the corresponding values by using Bland-Altman plot analysis. We outlined 73 ROIs including tumor sites, lymph nodes and normal tissue. The Bland-Altman plot analysis revealed that the two methods showed an accepted degree of agreement for blood flow, and, thus, can be used interchangeably for measuring this parameter. Slightly worse agreement was observed between v(1) in the DP model and BV but even here the two tracer kinetic analyses can be used interchangeably. Under consideration of whether both techniques may be used interchangeably was the case of t(1) and MTT, as well as for measurements of the PS values. The application of the proposed DP model is feasible in the clinical routine and it can be used interchangeably for measuring blood flow and vascular volume with the commercially available reference standard of the deconvolution-based approach. The lack of substantial agreement between the measurements of vascular transit time and permeability-surface area product may be attributed to the different tracer kinetic principles employed by both models and the detailed capillary tissue exchange physiological modeling of the DP technique.

Quality of life and salivary output in patients with head-and-neck cancer five years after radiotherapy

BACKGROUND

To describe long-term changes in time of quality of life (QOL) and the relation with parotid salivary output in patients with head-and-neck cancer treated with radiotherapy.

METHODS

Forty-four patients completed the EORTC-QLQ-C30(+3) and the EORTC-QLQ-H&N35 questionnaires before treatment, 6 weeks, 6 months, 12 months, and at least 3.5 years after treatment. At the same time points, stimulated bilateral parotid flow rates were measured.

RESULTS

There was a deterioration of most QOL items after radiotherapy compared with baseline, with gradual improvement during 5 years follow-up. The specific xerostomia-related items showed improvement in time, but did not return to baseline. Global QOL did not alter significantly in time, although 41% of patients complained of moderate or severe xerostomia at 5 years follow-up. Five years after radiotherapy the mean cumulated parotid flow ratio returned to baseline but 20% of patients had a flow ratio <25%. The change in time of xerostomia was significantly related with the change in flow ratio (p = 0.01).

CONCLUSION

Most of the xerostomia-related QOL scores improved in time after radiotherapy without altering the global QOL, which remained high. The recovery of the dry mouth feeling was significantly correlated with the recovery in parotid flow ratio.

Longitudinal scintigraphic study of parotid and submandibular gland function after total body irradiation in children and adolescents

OBJECTIVE

Total body irradiation (TBI) and cyclophosphamide (CY) during allogeneic stem cell transplantation (ASCT) cause salivary gland dysfunction in children. The aim of this investigation was to study the scintigraphic functional changes over time of the parotid and submandibular glands in children and young adults one year after treatment with CY and TBI at ASCT.

METHODS

Salivary gland scintigraphy (SGS) was performed before ASCT, and 3-6 months and 12 months after ASCT. The three male patients who fulfilled the scintigraphic study had a mean age (+/- SD) of 17.3 +/- 9.8 years at ASCT.

RESULTS

The parotid secretion capacity (SPar) was 83.5 +/- 3.2% before ASCT and 48.5 +/- 25.8% during the next 3-6 months (P < 0.05). The SPar did not increase (48.1 +/- 12.4%) during the rest of the first year after ASCT. The submandibular emptying capacity (SSub) was 91.3 +/- 12.9% before ASCT and 35.4 +/- 2.3% after 3-6 months (P < 0.05). The SSub was 87.9 +/- 17.9% one year after ASCT.

CONCLUSIONS

The parotid glands were more sensitive to irradiation since they did not recover lost capacity to secrete saliva, while the submandibular glands recovered the secretion capacity at the one-year follow-up.

Radiation-induced xerostomia in patients with head and neck cancer: a literature review

A dry mouth or xerostomia is one of the most common complications during and after radiotherapy for head and neck cancer, because irreparable damage is caused to the salivary glands, which are included in the radiation fields. Xerostomia not only significantly impairs the quality of life of potentially cured cancer patients, it may also lead to severe and long-term oral disorders. Because management of xerostomia is rarely effective, prevention is paramount. Several strategies have been developed to avoid radiation-induced salivary dysfunction without compromising definitive oncologic treatment. These include salivary gland-sparing radiation techniques, such as 3-dimensional conformal or intensity-modulated radiotherapy, concomitant cytoprotectants, and surgical salivary gland transfer. However, these preventive approaches are not applicable to all patients, and comprehensive scientific research that incorporates new biological insights is warranted to optimize the therapeutic index of radiotherapy for head and neck cancer.

Compensator-based intensity-modulated radiotherapy in head and neck cancer: our experience in achieving dosimetric parameters and their clinical correlation

AIMS

To review the Batra Hospital and Medical Research Centre experience of using compensator-based intensity-modulated radiotherapy (IMRT) to treat head and neck cancer.

MATERIALS AND METHODS

Between October 2003 and August 2004, 18 patients underwent IMRT for head and neck cancer at our institution. IMRT was delivered using partial transmission high-resolution compensator blocks.

RESULTS

With a median follow-up of 13.3 months, two patients had residual disease and two failed in the gross tumour volume (GTV). The complete response rate after surgical salvage was 94.5%. Both the locoregional relapse-free and disease-free survival rates were 81.8%. The target coverage in terms of average maximum, mean and minimum dose (in Gy) delivered was 78.6, 73.5 and 58.4 to the GTV-planning target volume, 82.3, 70.9 and 47.3 to clinical target volume 1 (CTV1) and 82.9, 66.2 and 29.6 to CTV2. The dose constraint of 30 Gy to less than 50% of the contralateral parotid volume was achieved in 12 (66.7%) patients. If the dose constraint was revised to 35 Gy, at least 50% of the parotid volume was spared in 17 (94.5%) patients. On average, 75% of the contralateral parotid volume received a dose less than 35 Gy in 13 (72.3%) patients with grade I xerostomia, whereas this was 49.3% in five (27.7%) patients with grade II xerostomia, and the difference was statistically significant (P = 0.001).

CONCLUSIONS

In our initial experience, compensator-based IMRT is feasible with regard to target coverage and parotid volume sparing. The parotid volume dose has significant clinical implications on the grade of xerostomia. Our results invoke rethinking into the issues of the parotid volume dose constraint in our subpopulation.

Can dose reduction to one parotid gland prevent xerostomia?--A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy

AIMS

Dryness of the mouth is one of the most distressing chronic toxicities of radiation therapy in head and neck cancers. In this study, parotid function was assessed in patients with locally advanced head and neck cancers undergoing intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Parotid function was assessed with the help of a questionnaire and parotid scintigraphy, especially with regards to unilateral sparing of the parotid gland.

MATERIALS AND METHODS

In total, 19 patients were treated with compensator-based IMRT between February 2003 and March 2004. The dose to the clinical target volume ranged between 66 and 70 Gy in 30-35 fractions to 95% of the isodose volume. Ipsilateral high-risk neck nodes received an average dose of 60 Gy and the contralateral low-risk neck received a dose of 54-56 Gy. Eight of 19 patients also received concomitant chemotherapy.

RESULTS

Subjective toxicity to the parotid glands was assessed with the help of a questionnaire at 0, 3 and 6 months and objective toxicity was assessed with parotid scintigraphy at 0 and 3 months. The mean dose to the ipsilateral parotid gland ranged from 19.5 to 52.8 Gy (mean 33.14 Gy) and the mean dose to the contralateral gland was 11.1-46.6 Gy (mean 26.85 Gy). At a median follow-up of 13 months, 9/19 patients had no symptoms of dryness of the mouth (grade I), 8/19 had mild dryness of the mouth (grade II) and only 2/19 had grade III xerostomia, although the parotid gland could only be spared on one side in most of the patients.

CONCLUSIONS

Minimising the radiation dose to one of the parotid glands with the help of IMRT in patients with advanced head and neck cancers can prevent xerostomia in most patients and parotid scintigraphy is a useful method of documenting xerostomia.

The impact of dose on parotid salivary recovery in head and neck cancer patients treated with radiation therapy

PURPOSE

A common side effect experienced by head and neck cancer patients after radiation therapy (RT) is impairment of the parotid glands' ability to produce saliva. Our purpose is to investigate the relationship between radiation dose and saliva changes in the 2 years after treatment.

METHODS AND MATERIALS

The study population includes 142 patients treated with conformal or intensity-modulated radiotherapy. Saliva flow rates from 266 parotid glands are measured before and 1, 3, 6, 12, 18, and 24 months after treatment. Measurements are collected separately from each gland under both stimulated and unstimulated conditions. Bayesian nonlinear hierarchical models were developed and fit to the data.

RESULTS

Parotids receiving higher radiation produce less saliva. The largest reduction is at 1-3 months after RT followed by gradual recovery. When mean doses are lower (e.g., <25 Gy), the model-predicted average stimulated saliva recovers to pretreatment levels at 12 months and exceeds it at 18 and 24 months. For higher doses (e.g., >30 Gy), the stimulated saliva does not return to original levels after 2 years. Without stimulation, at 24 months, the predicted saliva is 86% of pretreatment levels for 25 Gy and <31% for >40 Gy. We do not find evidence to support that the overproduction of stimulated saliva at 18 and 24 months after low dose in 1 parotid gland is the result of low saliva production from the other parotid gland.

CONCLUSIONS

Saliva production is affected significantly by radiation, but with doses <25-30 Gy, recovery is substantial and returns to pretreatment levels 2 years after RT.

Parotid-sparing intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma: Preserved parotid function after IMRT on quantitative salivary scintigraphy, and comparison with historical data after conventional radiotherapy

PURPOSE

To evaluate the parotid function after parotid-sparing intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

From March 2003 to May 2004, 16 patients with nonmetastatic NPC underwent parotid-sparing IMRT. Eight of these patients had Stage III or IV NPC based on the 1997 American Joint Committee on Cancer staging system. The post-IMRT parotid function was evaluated by quantitative salivary scintigraphy and represented by the maximal excretion ratio (MER) of the parotid gland after sialogogue stimulation. The parotid function of 16 NPC patients who were previously treated with conventional radiotherapy was reviewed as the historical control.

RESULTS

In the parotid-sparing IMRT group, all 16 patients were alive and without cancer at the end of follow-up period (median, 24.2 months). The mean parotid MER was 53.5% before radiotherapy, 10.7% at 1 month post-IMRT, and 23.3% at 9 months post-IMRT. In the conventional radiotherapy group, the mean parotid MER was 0.6% at 6 to 12 months postradiotherapy. The difference was statistically significant (23.3% vs. 0.6%, p<0.001, Mann-Whitney test). In the IMRT group, the mean parotid doses ranged from 33.2 Gy to 58.8 Gy (average, 43.9 Gy). The correlation between the mean parotid dose and the percentage decrease of parotid MER at 9 months post-IMRT (dMER) was statically significant (p=0.008, Pearson correlation).

CONCLUSIONS

Although the mean parotid doses are relatively high, the significant preservation of parotid function is achieved with IMRT for NPC patients. The significant correlation between mean parotid dose and parotid dMER demonstrates the dose-function relationship of the parotid gland.

Prevention and treatment of dysphagia and aspiration after chemoradiation for head and neck cancer

Safe, successful swallowing depends on complex events affected by head and neck cancers and their treatment. This article reviews the swallowing process, how it is affected by chemoradiotherapy, and the evaluation, prevention, and treatment of swallowing disorders. Specific recommendations are made to promote maintenance and recovery of swallowing function.

Oral complications of radiotherapy

Radiotherapy-induced damage in the oral mucosa is the result of the deleterious effects of radiation, not only on the oral mucosa itself but also on the adjacent salivary glands, bone, dentition, and masticatory musculature and apparatus. Biological response modifiers, cytoprotective drugs, salivary-sparing radiation techniques, and surgery have been introduced to combat and, more importantly, to prevent, the development of these complications. Radiotherapy-induced oral complications are complex, dynamic pathobiological processes that lower the quality of life and predispose patients to serious clinical disorders. Here, we focus on these oral complications of radiotherapy, highlight preventive and therapeutic developments, and review the current treatment options available for these disorders.

Evaluation of parotid gland function following intensity modulated radiation therapy for head and neck cancer

PURPOSE

This study was undertaken to determine the parotid gland tolerance dose levels following intensity modulated radiation therapy (IMRT) for treating patients who suffered with head and neck cancer.

MATERIALS AND METHODS

From February 2003 through June 2004, 34 head and neck patients with 6 months of follow-up were evaluated for xerostomia after being treated by IMRT. Their median age was 59 years (range: 29~78). Xerostomia was assessed using a 4-question xerostomia questionnaire score (XQS) and a test for the salivary flow rates (unstimulated and stimulated: USFR and SSFR, respectively). The patients were also given a validated LENT SOMA scale (LSS) questionnaire. Evaluations were performed before IMRT and at 1, 3 and 6 months after IMRT.

RESULTS

All 34 patients showed significant changes in the XQS, LSS and Salivary Flow rates (USFR and SSFR) after IMRT. No significant changes in the XQS or LSS were noted in 12 patients who received a total parotid mean dose of 3,100 cGy, significant increases in the XQS and LSS were observed. The USFR and SSFR from the parotid glands in 7 patients who received 2,750 cGy were significantly lower than the baseline values at all times after IMRT.

CONCLUSION

We suggest that the total parotid mean dose should be limited to Collapse

Key Words

• IMRT (intensity modulated radiation therapy)
• Parotid gland
• Salivary flow rate
• Xerostomia

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Affiliation(s)

Seok Ho Lee Research Institute and Hospital, National Cancer Center, Goyang, Korea
Tae Hyun Kim Research Institute and Hospital, National Cancer Center, Goyang, Korea
Joo Young Kim Research Institute and Hospital, National Cancer Center, Goyang, Korea
Sung Yong Park Research Institute and Hospital, National Cancer Center, Goyang, Korea
Hong Ryull Pyo Research Institute and Hospital, National Cancer Center, Goyang, Korea
Kyung Hwan Shin Research Institute and Hospital, National Cancer Center, Goyang, Korea
Dae Yong Kim Research Institute and Hospital, National Cancer Center, Goyang, Korea
Joo Young Kim Research Institute and Hospital, National Cancer Center, Goyang, Korea
Kwan Ho Cho Research Institute and Hospital, National Cancer Center, Goyang, Korea

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Dramatic and prolonged decrease of whole salivary secretion in nasopharyngeal carcinoma patients treated with radiotherapy

OBJECTIVES

This study evaluates: (1) the change in whole salivary secretion rates of nasopharyngeal carcinoma patients before, during, and after radiotherapy, especially during the first week of irradiation; (2) the recovery capability of salivary glands up to 2 years postirradiation; and (3) the possible prognostic factors affecting salivary gland functions.

STUDY DESIGN

Fifty patients who completed conventional radiotherapy using either once-per-day or hyperfractionated technique were included. Both unstimulated and stimulated whole salivary flow rates and ratios (flow rate compared with baseline) were measured before, during, 1, 3, and 6 months, and 1 and 2 years after radiotherapy. Multivariate analysis of potential prognostic factors affecting the salivary secretion ratio was made.

RESULTS

Salivary glands were very radiosensitive and responded to radiation very early. After 720 cGy at the fourth day of the 8-week treatment, the unstimulated and stimulated salivary flow rates had decreased by 40%-50%. The nadir was reached in many patients after 3600 cGy (4 weeks). A second phase of decrease in salivary secretion was noted after completion of radiotherapy.

CONCLUSIONS

Different mechanisms may be responsible for salivary response after low and high dose of radiation. This study shows no recovery of salivary secretion during the follow-up period, and the best strategy for managing radiation-induced salivary gland damage may be reduction of radiation dose to the glands.

Effects of sucking acidic candies on saliva in unilaterally irradiated pharyngeal cancer patients

Patients who have received radiation therapy on the head and neck area often use acidic candies to relieve symptoms of dry mouth. Therefore, the aim of this study was to determine the erosive potential in relation to teeth of an acidic candy in 10 such patients. The patients sucked the candy while their whole saliva was collected into a closed system at different times: baseline, candy-stimulated, and post-stimulated. The erosive potential of the candy was evaluated from candy-induced changes in saliva degree of saturation with respect to hydroxyapatite (HAp). Previously published normative values were used for comparison. The results showed that saliva became significantly more undersaturated with respect to HAp in irradiated patients, and failed to return to baseline values during the post-stimulatory period, which it normally does in healthy individuals. Thus, prevention of dental breakdown in these patients should involve counseling regarding choice of stimulant for dry mouth relief.

Mucoepidermoid carcinoma of salivary glands in the pediatric age group: 18 clinical cases, including 11 second malignant neoplasms

BACKGROUND

Salivary gland tumors represent 1% of head and neck tumors, with only 5% of these occurring in patients younger than 20 years. Mucoepidermoid carcinoma (MEC) is one of the most frequent salivary gland cancers among adults and children.

METHODS

This survey was conducted among 34 French pediatric oncology departments. From 1980 to 2000, 18 cases were reported.

RESULTS

Treatment included surgery or radiotherapy, or both. The 5-year survival rate was 93.7%. Eleven patients had been previously treated by radiotherapy and/or chemotherapy for a first malignant tumor, specifically, lymphoid leukemia (n = 4), lymphoma (n = 3), brain tumor (n = 2), sarcoma (n = 1), and retinoblastoma (n = 1).

CONCLUSIONS

MEC is very rare in the pediatric age group. Treatment involves surgical removal of the tumor plus radiotherapy, according to histologic staging. MEC has a good prognosis in young patients. The survival rate does not differ in the subgroup of patients with MEC as a secondary tumor.

PET-CT vs contrast-enhanced CT: What is the role for each after chemoradiation for advanced oropharyngeal cancer?

PURPOSE

The aim of our study was to assess the utility of positron emission tomography (PET) and 2 fluoro-2-deoxy-D-glucose coupled with neck CT compared with contrast-enhanced CT in predicting persistent cancer either at the primary site or cervical lymphatics in patients with oropharyngeal cancer treated with concurrent chemoradiation

METHODS

Thirty consecutive patients underwent clinical examination, PET-CT, and contrast-enhanced CT to assess response after the completion of the treatment. The outcome variable was positive tissue diagnosis or negative disease at 6 months. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the primary site as well as cervical disease.

RESULTS

Contrast-enhanced CT alone showed the best accuracy in detecting disease at the primary site after treatment (85.7%). Accuracy in evaluating residual tumor in the cervical lymphatics for contrast-enhanced CT and PET-CT was 59.3% and 74.1%, respectively. For evaluating the neck, PET-CT and contrast-enhanced CT demonstrated 100% NPV, but the PPV was 36.3% and 26.6%, respectively.

CONCLUSIONS

In this preliminary study, PET-CT seems to be superior to contrast-enhanced CT in predicting persistent disease in the neck after chemoradiation for oropharyngeal or unknown primary cancer, but not at the primary site. However, the possibility of a false-positive result in the neck remains high, and thus overtreatment may result. Even more concerning are the false-negative results. Larger, prospective studies will be important in defining the role of PET-CT in obviating the need for salvage neck dissections after chemoradiation.

Swallowing outcomes after radiotherapy for head and neck cancer: A systematic review

BACKGROUND

A systematic review of the current data on swallowing function after radiotherapy or chemoradiotherapy is presented.

METHODS

Electronic databases were searched for 1966-2005. Papers were categorized according to level of evidence, methodological quality, and the specific domain of swallowing being measured.

RESULTS

Of 109 papers retrieved, 33 were identified and reviewed. Evidence was primarily classified as either level III.2 (cohort studies) or level IV (case series). Methodological quality was found to be compromised in most studies. Although many researchers had investigated swallowing impairment, a wide variety of measurement tools were employed.

CONCLUSIONS

There are limited data on swallowing outcomes after radiotherapy or chemoradiotherapy for head and neck cancer. Further work is needed to ascertain which aspects of swallowing should be measured, and then to use such measures in well-designed clinical trials and prospective cohort studies of this under-researched population.

Prospective study of the long term change of the oral flora after radiation therapy

OBJECTIVES

The aim of this prospective study was to evaluate the long term change in oral pathogens following radiation therapy.

METHODS

Twenty-two patients with planned radiation therapy (>30 Gy) of head and neck squamous cell carcinoma were included. Before radiation therapy, after 3, 6, and 12 months samples from the deepest periodontal pocket were drawn. Five major periodontal pathogens were studied using DNA probes (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteriodes forsythus, Treponema denticola). Stimulated saliva was sampled for the microbiologic study of caries pathogens (streptococci and lactobacilli). Plaque index and decayed, missing, filled tooth surfaces (DMF-S) were recorded.

RESULTS

A normalisation of the caries bacteria is not found correlating to a significant increase in the number of affected teeth (DMF-S) from 80.7 to 88.5 after 12 months. The plaque index remained unchanged. The incidence of periodontal pathogens did not significantly change during the follow up.

CONCLUSION

In contrast to radiation caries there seems to be no microbiological evidence for "radiation periodontitis". Despite of the intensive oral hygiene no reduction of the high number of caries pathogens is found, which leads to a high risk of tooth decay even 12 months after radiation.

A mouse caries model and evaluation of aqp5-/- knockout mice

Current techniques to alter gene expression in mice allow direct analysis of the net role of a host factor in caries development. Towards this goal we first established protocols to induce and score caries in NFS/N mice and determined caries susceptibility in mice with targeted deletion of the gene encoding aquaporin-5 (Aqp5-/-), a water channel involved in the production of saliva. In the NFS/N strain of mice total sulcal caries and severity scores were consistent between experiments, whereas smooth surface caries scores were lower, more variable but distributed fairly evenly among the buccal, lingual and sulcal surfaces. In Black Swiss/129SvJ mice (genetic background of Aqp5-/- mice) caries scores were 50-75% lower compared to NFS/N mice, suggesting strain variation in caries susceptibility under our experimental conditions. In Aqp5-/- mice, in which the volume of total salivary secretion is reduced by 60-65%, there was a significant increase in caries, primarily on the buccal and sulcal surfaces. Results indicate that caries susceptibility increases with a reduced salivary flow that is associated with decreased water content of saliva.

Does radiation dose to the salivary glands and oral cavity predict patient-rated xerostomia and sticky saliva in head and neck cancer patients treated with curative radiotherapy?

BACKGROUND AND PURPOSE

To investigate the association between the mean salivary gland and oral cavity dose, with patient-rated moderate and severe xerostomia and sticky saliva.

PATIENTS AND METHODS

One hundred and fifty-seven patients treated with bilateral irradiation for head and neck cancer were included. The parotid and submandibular glands and the oral cavity were delineated on plannings-CT scans. At baseline and 6 and 12 months self-reported xerostomia and sticky saliva were assessed using the EORTC QLQ-H&N35 questionnaire.

RESULTS

At 6 months a significant association between the mean parotid (MD(par)) and mean submandibular dose (MD(subm)) and xerostomia was observed (OR - MD(par): 1.17; P=0.002 and OR - MD(subm): 1.08; P = 0.02). Between MD(par) and MD(subm), a significant interaction term was present. No significant association was found with the oral cavity dose. Xerostomia was reversible depending on MD(par) and MD(subm). Considering Sticky saliva, a significant association was found at 6 and 12 months with MD(subm) (OR: 1.03; P < 0.001). The P50 for sticky saliva increased with elapsing time.

CONCLUSIONS

Both MD(par) and MD(subm) influence the risk of xerostomia in irradiated patients at 6 months. This probability as a function of the mean parotid dose significantly depended on the mean dose in the submandibular glands. Sticky saliva mainly depends on MD(subm).

Eating Problems and Weight Loss for Patients With Head and Neck Cancer

This descriptive study aimed to examine the occurrence and treatment of eating problems, and their causes and consequences during the trajectory of care for patients with head and neck cancer treated with radiotherapy. The method used was a review of patient records, conducted by means of an audit instrument developed for the study. The instrument audits demographic data and documented eating problems, their causes and consequences, and undertaken interventions in medical and nursing records from diagnosis until 1 year after completion of treatment. Data were collected prior to treatment, each week during radiotherapy and at the follow-up visits to the physician 1, 6, and 12 months after completion of treatment. The results show that eating problems were common before treatment started, and at the end of radiotherapy every patient suffered from eating problems. One year after treatment the majority still had eating problems. Weight loss occurred early during radiotherapy and became aggravated after treatment, but was not treated to an adequate extent. Implications of this study are that nutritional interventions must be initiated before the treatment starts and they need to be ongoing after completion of treatment.

Secondary radiation damage as the main cause for unexpected volume effects: a histopathologic study of the parotid gland

PURPOSE

To elucidate with a histopathological study the mechanism of region-dependent volume effects in the partly irradiated parotid gland of the rat.

METHODS AND MATERIALS

Wistar rats were locally X-irradiated with collimators with conformal radiation portals for 100% volume and 50% cranial/caudal partial volumes. Single doses up to 40 Gy were applied. Parotid saliva samples were collected, and the three lobes of the parotid gland were examined individually on the macro- and micromorphologic level up to 1 year after irradiation.

RESULTS

Dose-dependent loss of gland weight was observed 1 year after total or partial X-irradiation. Weight loss of the glands correlated very well with loss of secretory function. Irradiating the cranial 50% volume (implicating a shielded lateral lobe) resulted in substantially more damage in terms of weight loss and loss of secretory function than 50% caudal irradiation (shielding the ventral and dorsal lobe). Histologic examinations of the glands 1 year after irradiation revealed that the shielded lateral lobe was severely affected, in contrast to the shielded ventral and dorsal lobes. Time studies showed that irradiation of the cranial 50% volume caused late development of secondary damage in the shielded lateral lobe, becoming manifest between 240 and 360 days after irradiation. The possible clinical significance of this finding is discussed.

CONCLUSION

It is concluded that the observed region-dependent volume effect for late function loss in the rat parotid gland after partial irradiation is mainly caused by secondary events in the shielded lateral lobe. The most probable first step (primary radiation event) in the development of this secondary damage is radiation exposure to the hilus region (located between the ventral and dorsal lobe). By injuring major excretory ducts and supply routes for blood and nerves in this area, the facility system necessary for proper functioning of the nonexposed lateral lobe is seriously affected. The unexpected volume effect in the rat might have consequences for treatment strategies in radiotherapy, implicating not only salivary glands but also other organs with a seemingly homogeneous distribution of radiosensitive elements, a situation wherein volume effects have not been anticipated up to now.

Clinical photodynamic therapy of head and neck cancers-A review of applications and outcomes

As local control is tantamount to cure in head and neck cancer, an aggressive regimen of surgery and radiation remains the standard of care for most patients. Despite significant technical advances, these treatments are highly morbid. Further, patients who fail treatment have limited salvage options. Photodynamic therapy (PDT) and photodiagnosis (PD) of head and neck cancer offer significant potential for improved outcomes in a myriad of clinical indications ranging from in situ to recurrent disease. However, despite promising results, these modalities remain at the fringe of head and neck treatment options. Photofrin(®), Photosan and Foscan(®) are photosensitizers used clinically in head and neck PD/PDT. In addition, aminolevulinic acid (ALA), which gives origin to Protoporphyrin IX, an endogeneous photosensitizer, is also used for PD/PDT. We review the clinical literature on these photosensitizers to assist in the integration of these important modalities into the mainstream of head and neck oncological therapy.

On the mechanism of salivary gland radiosensitivity

PURPOSE

To contribute to the understanding of the enigmatic radiosensitivity of the salivary glands by analysis of appropriate literature, especially with respect to mechanisms of action of early radiation damage, and to supply information on the possibilities of amelioration of radiation damage to the salivary glands after radiotherapy of head-and-neck cancer.

METHODS AND MATERIALS

Selected published data on the mechanism of salivary gland radiosensitivity and radioprotection were studied and analyzed.

RESULTS

From a classical point of view, the salivary glands should not respond as rapidly to radiation as they appear to do. Next to the suggestion of massive apoptosis, the leakage of granules and subsequent lysis of acinar cells was suggested to be responsible for the acute radiation-induced function loss of the salivary glands. The main problem with these hypotheses is that recently performed assays show no cell loss during the first days after irradiation, while saliva flow is dramatically diminished. The water secretion is selectively hampered during the first days after single-dose irradiation. Literature is discussed that shows that the compromised cells suffer selective radiation damage to the plasma membrane, disturbing signal transduction primarily affecting watery secretion. Although the cellular composition of the submandibular gland and the parotid gland are different, the damage response is very alike. The acute radiation-induced function loss in both salivary glands can be ameliorated by prophylactic treatment with specific receptor agonists.

CONCLUSIONS

The most probable mechanism of action, explaining the enigmatic high radiosensitivity for early effects, is selective radiation damage to the plasma membrane of the secretory cells, disturbing muscarinic receptor stimulated watery secretion. Later damage is mainly due to classical mitotic cell death of progenitor cells, leading to a hampered replacement capacity of the gland for secretory cells, but is also caused by damage to the extracellular environment, preventing proper cell functioning.

Effects of EGF and bFGF on Irradiated Parotid Glands

Radiotherapy is common treatment for head-and-neck cancer, during which the salivary glands are often included within the radiation field. The most common side effect of this treatment is the development of oral dryness (xerostomia). This study considers the administration of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF or FGF2) at physiological concentrations before and after irradiation in order to repair radiation-induced damage in salivary gland cells. As a preliminary examination of the efficacy of this approach we have characterized the effects of EGF and bFGF on the apoptotic response of 15-Gy irradiated rat salivary glands in vitro. Also, we have developed a controlled-release delivery system to effectively administer the growth factor to the gland since local delivery is essential to avoid unwanted protection of cancer cells. In vitro administration of bFGF prior to and immediately after irradiation partially protected (44%) the rat parotid gland. EGF did not show any significant radioprotective effect on parotid glands after a single 15-Gy irradiation dose. Encapsulation, storage and release of bFGF from biodegradable 50/50 PLGA microspheres did not affect the functionality of the growth factor in vitro.

Toxicity and compliance of subcutaneous amifostine in patients undergoing postoperative intensity-modulated radiation therapy for head and neck cancer

Standard conventional radiation therapy for advanced head and neck tumors typically involves administering high radiation dose to the major salivary glands bilaterally. In most cases, this causes a marked reduction in oral saliva output. Xerostomia is one of the most prevalent late side effects of radiation for head and neck malignancies, and patients cite it as the major cause of decreased quality of life. The degree of xerostomia has been reported to depend on the radiation dose and volume of salivary gland irradiated. Several studies show dose-volume-response relationships in the salivary glands, suggesting the possibility of significant improvement in saliva production postradiation, as well as quality of life, if radiation techniques can spare the salivary glands. A growing body of literature supports the premise that intensity-modulated radiation therapy (IMRT) allows irradiation of tumor targets in the head and neck while sparing substantial portions of salivary glands. Early clinical experience has shown substantial sparing of salivary flow following IMRT, and suggests at least equal tumor control but improved xerostomia compared with patients receiving standard radiation techniques. We hypothesize that the addition of a radiation protector, such as amifostine (Ethyol; Medimmune Inc, Gaithersburg, MD) may further improve salivary function over that obtained with IMRT alone. To test this hypothesis, we have initiated a pilot clinical trial to compare unstimulated and stimulated salivary flow rates 6 months and 1 year after IMRT + amifostine with historic controls treated with IMRT alone. Twenty-seven patients have been accrued onto this trial, and the toxicity and compliance data are reported herein.

Serum cystatin C in patients with head and neck carcinoma

BACKGROUND

The balance between proteinases of various classes and their inhibitors was found to be of critical importance for local invasion and metastasizing of tumor cells. The aim of the present study was to determine the changes in the serum cystatin C concentration in patients with squamous cell carcinoma of the head and neck.

METHODS

In the sera of 34 patients with squamous cell carcinoma of the head and neck, the concentration of cysteine proteinase inhibitor cystatin C was determined using ELISA. The serum samples were collected at diagnosis (group A) and 7 to 407 days (median, 59 days) after the therapy (group B). The sera of 30 healthy blood donors served as controls (group C).

RESULTS

A significant increase in the median concentration of cystatin C was found in the patients' sera (group A: 573 ng/ml, P<0.0001; group B: 551 ng/ml, P<0.0001) compared to control group C (320 ng/ml), whereas no difference was observed between groups A and B (P>0.05). Cystatin C concentrations in the sera of group A correlated with the site of primary tumor (P=0.035), being higher in the patients with non-laryngeal tumors (658 ng/ml) than in those with larynx primaries (529 ng/ml). There was a significant trend (RS=-0.535, P=0.049) towards lower cystatin C concentrations with an increasing time delay in post-treatment serum sampling (group B), which was observed in the patients with no relapse of the disease and a sampling later than 45 days after the completion of therapy.

CONCLUSIONS

These results add to the knowledge of the role of cystatin C in invasive behavior of squamous cell carcinoma of the head and neck, and suggest its potential role as a tumor marker in this particular type of cancer.

Evaluations of quality of life and organ function

For advanced head and neck cancer (HNC) patients, aggressive radiation and chemoradiation treatments offer new therapy options. The aims of these regimens are increased survival and organ preservation, with the goals of preserving organ function, minimizing late effects, and improving quality of life (QOL). At the same time, the toxicities of these regimens are acknowledged as is the potential for long-term dysfunction. Thus, particularly now, with the increasing use of aggressive chemoradiation therapy (CRT) regimens, documentation of the QOL and functional outcomes of these treatments is critical. The implications for speech and swallowing are widely recognized and the broader effects of these impairments on overall QOL have received some attention. This article presents data on the performance, functional, and QOL results of radiation therapy (RT) and various CRT regimens in HNC.

Impact of dysphagia on quality-of-life in nasopharyngeal carcinoma

BACKGROUND

Little is known about dysphagia or quality of life (QOL) in patients treated for nasopharyngeal carcinoma (NPC). The aim of this study was to determine the impact of dysphagia on QOL in patients treated for NPC as measured by two standard tools, the University of Washington Quality-of-Life Questionnaire(1) (UW-QOL) and the Swallow Quality-of-Life Questionnaire(3) (SWAL-QOL).

METHODS

This is a cross-sectional survey of 59 consecutive disease-free survivors of NPC attending the head and neck cancer clinic at the National University Hospital, Singapore. The UW-QOL and SWAL-QOL underwent minor modification and were translated into Mandarin. A linear regression analysis was performed to identify significant predictors of health-related QOL.

RESULTS

Fifty-one patients (86%) responded; of these, 43 had self-reported swallowing difficulties. On the UW-QOL, respondents indicated the three most important issues to be swallowing (59%), hearing (45%), and saliva/dry mouth (41%). Respondents with swallowing difficulty reported a lower UW-QOL composite score (p = .002) and a lower health-related QOL score (HR-QOL) than those without swallowing difficulty (p = .004). Self-reported swallowing difficulty predicted a lower HR-QOL score (p = .004). A longer time since treatment predicted a better score in HR-QOL (p = .024). A lower score in fatigue predicted a lower HR-QOL score (p = .001).

CONCLUSIONS

Swallowing difficulties negatively impact QOL. It is recommended that future QOL studies aimed specifically at swallowing function in NPC use a swallowing specific questionnaire (eg, SWAL-QOL) in addition to a head and neck-specific measure. Further research is needed to look at the adaptation and usefulness of swallowing-specific QOL surveys for use with people treated for NPC.

Intensity modulated radiotherapy for head and neck cancer: evidence for preserved salivary gland function

BACKGROUND AND PURPOSE

To investigate the salivary gland function following intensity modulated radiotherapy (IMRT) for head and neck cancer.

PATIENTS AND METHODS

Seventeen patients with oropharyngeal (n=11) or nasopharyngeal (n=6) carcinoma located adjacent to the major salivary glands were treated with IMRT with an emphasis to spare the salivary glands from high-dose irradiation and to reduce the risk of postirradiation xerostomy. Three patients had stage 2, 4 stage III, and 10 stage IVA cancer. The total basal and stimulated saliva flow rates were measured before the treatment, and 6 and 12 months after radiotherapy.

RESULTS

The median basal saliva flow rate measured before radiation treatment was 0.13 mL/min, and at 6 and 12 months after the completion of IMRT 0.04 mL/min and 0.07 mL/min, respectively. The corresponding median stimulated saliva flow rates were 0.49 mL/min, 0.33 mL/min, and 0.45 mL, respectively. The D50 for an impaired stimulated parotid gland saliva flow rate was 25.5 Gy. Only two (12%) patients developed grade 3 and none grade 4 xerostomia during a median follow-up of 24 months (range, 12-40 months). No patients had locoregional cancer recurrence following IMRT.

CONCLUSIONS

The results suggest that much of the salivary gland function can be maintained with IMRT without jeopardizing the local control rate in the treatment of locally advanced oropharynx or nasopharynx carcinoma.

Current practice and knowledge of oral care for cancer patients: a survey of supportive health care providers

BACKGROUND

The Oral Care Study Section of the Multinational Association of Supportive Care in Cancer (MASCC) and the International Society for Oral Oncology (ISOO) conducted a survey on clinical practices of oral/dental management of cancer patients among supportive health care providers. The main purpose was to evaluate the knowledge and current practice for preventing and managing oral side effects associated with intensive chemotherapy (ICT), hematopoietic cell transplant (HCT), and radiation therapy to the head and neck (H&N RT).

MATERIALS AND METHODS

A questionnaire designed and pretested was sent to 212 MASCC/ISOO members around the world with different dental and medical backgrounds.

MAIN RESULTS

Seventy-four individuals (35%) responded. The majority of respondents were aware of possible oral complications and provided patients with clinical strategies and recommendations although there was considerable variability among the respondents. Approximately 75% stated that patients were referred for oral/dental care prior to H&N RT and ICT including HCT. However, integrated dental and medical services were reported available in only about 25% of the institutions, and most patients were referred to community-based dental professionals.

MAIN CONCLUSIONS

The survey represents a first review of current, international oral care practices. It suggests a need to develop evidence-based clinical guidelines to support effective oral/dental interventions and management strategies for this population. Furthermore, strategies for implementation of oral care protocols and better integration of dental and medical services should be developed. Caution in interpreting these findings is urged due to the limited response rate.

Simultaneous integrated boost intensity-modulated radiotherapy for locally advanced head-and-neck squamous cell carcinomas: II—clinical results

PURPOSE

To perform a Phase I radiation dose-escalation trial to determine the maximal tolerable dose (MTD) deliverable to the gross tumor volume (GTV) using an accelerated fractionation with simultaneous integrated boost intensity-modulated radiotherapy regimen with parotid gland sparing as the sole therapy in the treatment of locally advanced head-and-neck squamous cell carcinoma. The primary objective was the definition of the MTD using established criteria of quantifying acute dose-limiting toxicity (DLT). Secondary objectives included analysis of failure patterns, tumor control rates, and toxicity.

METHODS AND MATERIALS

Between July 1999 and June 2002, eligible patients with bulky Stage II to Stage IVB head-and-neck squamous cell carcinoma, excluding laryngeal primaries, were enrolled. Intensity-modulated radiotherapy was delivered with 6-MV photons using a "sliding-window" technique. Enrollment of 6 patients for each dose level was planned; if DLTs were seen in >2 of 6 patients, the previous dose was to be expanded by an additional 6 patients to confirm that dose level as the MTD. All schedules administered a total of 30 fractions, but with escalating doses per fraction (2.27, 2.36, and 2.46 Gy) to achieve a total dose to the GTV of 68.1, 70.8, and 73.8 Gy, respectively. The remaining target tissues were constrained to receive the same dose in all patients regardless of the GTV dose level. The clinical target volume, defined as tissue within 1 cm around the GTV (at high risk of subclinical disease), received 60 Gy in 30 fractions of 2.0 Gy. The electively irradiated target volume, defined as the clinically uninvolved lymph node-bearing tissues, received 54 Gy in 30 fractions of 1.8 Gy. The parotid glands were spared to the degree possible without compromising target coverage. Acute toxicity was scored weekly using National Cancer Institute Common Toxicity Criteria. DLT was defined as any Grade 4 acute toxicity or any acute toxicity requiring either a dose reduction or a treatment break of >5 treatment days.

RESULTS

Of 18 men and 2 women (average age, 57 years; range, 37-80 years), 17 presented with oropharyngeal primary tumors, and 1 each with squamous cell carcinoma of the oral cavity, nasopharynx, and hypopharynx. None of the 6 patients at dose level 1, and 2 of the 6 patients initially enrolled at dose level 2, developed DLT. Both patients treated at dose level 3 required a 3-day treatment break and dose reduction after rapid development of Grade 3 toxicity (by Day 15). Six additional confirmatory patients subsequently enrolled at dose level 2 completed treatment without DLT. At least 50% of the total parotid gland volume received <30 Gy in 14 patients (average, 54% of volume), with an average mean dose of 32 Gy. In contrast, >/=50% of the distal parotid gland volume received <25 Gy in 15 patients (average, 63% of volume), with an average mean dose of 24 Gy. With a median follow-up of 20 months from the date of enrollment and 28 months for surviving patients, the actuarial 2-year local control (primary site), regional control (nodal sites), and distant control rate was 76.3%, 66.7%, and 71.8%, respectively.

CONCLUSION

Dose level 2, 70.8 Gy in 30 fractions of 2.36 Gy, was defined as the MTD deliverable to the GTV using this accelerated fractionation with simultaneous integrated boost intensity-modulated radiotherapy regimen with parotid gland sparing as the sole treatment for locally advanced head-and-neck squamous cell carcinoma. Adequate parotid sparing was achievable in most cases. Early toxicity, tumor control, and survival rates compared favorably with the outcomes after other accelerated regimens.

Intensity-modulated radiotherapy for early-stage nasopharyngeal carcinoma: a prospective study on disease control and preservation of salivary function

BACKGROUND

Xerostomia is a uniform complication after radiotherapy (RT) for nasopharyngeal carcinoma (NPC). Dosimetric studies suggested that intensity-modulated RT (IMRT) can spare part of the parotid glands from high-dose radiation. Disease control and salivary function after IMRT for early-stage NPC was studied prospectively.

METHODS

Thirty-three patients with T1,N0-N1,M0 NPC were treated with IMRT from 2000 to 2002. The prescribed dose was 68-70 grays (Gy) in 34 fractions to gross tumor volume, 64-68 Gy to the planning target volume, and 70 Gy to enlarged cervical lymph nodes. Nineteen patients had stimulated whole salivary (SWS) flow assessment and stimulated parotid salivary (SPS) flow assessment at baseline and at 2 months, 6 months, 12 months, 18 months, and 24 months after the completion of IMRT.

RESULTS

At a median follow-up of 2 years, only 1 neck failure was observed. The 2-year and 3-year local control, distant metastases-free, and overall survival rates all were 100%. The lymph node control and progression-free survival rates were 100% at 2 years and 92.3% at 3 years, respectively. The average mean dose to the parotid gland was 38.8 Gy. The SWS and SPS flow showed continuous recovery: 60% and 47.1% of patients recovered at least 25% of their baseline SPS flow and SWS flow, respectively, at 1 year after completion of IMRT, and the proportions rose to 85.7% and 71.4%, respectively, by 2 years. The pH and buffering capacity of saliva also improved with time.

CONCLUSIONS

Parotid-sparing IMRT achieved good locoregional control, and there was continuous recovery of salivary flow, pH, and buffering capacity in the first 2 years after IMRT in patients with NPC.

Scintigraphic assessment of early and late parotid gland function after radiotherapy for head-and-neck cancer: a prospective study of dose-volume response relationships

PURPOSE

To investigate the value of scintigraphy as an indirect measurement of parotid function after radiotherapy (RT).

METHODS AND MATERIALS

Ninety-six patients with primary or postoperative RT for various malignancies in the head-and-neck region were prospectively evaluated. Parotid gland scintigraphy was performed before RT and 6 weeks and 1 year after RT. The uptake, excretion fraction of the saliva from the parotid gland to the oral cavity (SEF), and the ratios of uptake and SEF after and before treatment were calculated. CT-based treatment planning was used to derive dose-volume histograms of the parotid glands. To establish the effects of both the radiation dose and the volume of the parotid gland irradiated, the normal tissue complication probability model proposed by Lyman was fit to the data.

RESULTS

The mean maximal uptake of 192 parotid glands decreased significantly from 3329 counts (ct)-/s before RT to 3084 ct/s and 3005 ct/s at 6 weeks and 1 year after RT. The SEF before treatment was 44.7%. The SEF decreased to 18.7% at 6 weeks after RT, but recovered to a SEF of 32.4% at 1 year after RT. A significant correlation was found between the uptake 1 year after RT and the mean parotid dose. The reduction in post-RT SEF correlated significantly with the mean parotid gland dose. The normal tissue complication probability model parameter TD50 was found to be 29 and 43 Gy at 6 weeks and 1 year after RT, respectively, when a complication was defined as a posttreatment SEF parotid ratio of <45%.

CONCLUSIONS

The effects of radiation on parotid gland function using scintigraphy could be well established. A statistically significant correlation between the SEF ratio and the mean parotid dose was shown, with some recovery of function at 1 year after RT, comparable with the flow results. When direct flow measurements are not feasible, parotid scintigraphy appears to be a good indicator of gland function.

Use of modified Northwick Park Neck Pain Questionnaire in patients with postirradiation neck disability: Validation study

BACKGROUND

No available measure exists for postirradiation neck disability. Adoption of the Chinese Northwick Park Neck Pain Questionnaire (NPQ) for patients with postirradiation neck disability was examined in this study.

METHODS

Eight physiotherapists and five patients were invited to test the validity of the content. Forty-three patients with neck disability were recruited to evaluate test-retest reliability and internal consistency. The level of neck discomfort, range of neck motion and maximal isometric neck muscle strength, and SF-36 health score were measured for construct validity testing.

RESULTS

The questionnaire had good content validity, a high degree of test-retest reliability, internal consistency (intraclass correlation coefficient [ICC], 0.94; Cronbach's alpha, 0.88), and good construct validity. NPQ correlated significantly with most of the subscores of SF-36 (r(s), -0.43 to - 0.71) and numeric rating scale (r(s) = 0.69).

CONCLUSION

The modified Chinese NPQ was found to be reliable and valid for the evaluation of postirradiation neck disability.