3D Variation in delineation of head and neck organs at risk.

BACKGROUND: Consistent delineation of patient anatomy becomes increasingly important with the growing use of highly conformal and adaptive radiotherapy techniques. This study investigates the magnitude and 3D localization of interobserver variability of organs at risk (OARs) in the head and neck area with application of delineation guidelines, to establish measures to reduce current redundant variability in delineation practice. METHODS: Interobserver variability among five experienced radiation oncologists was studied in a set of 12 head and neck patient CT scans for the spinal cord, parotid and submandibular glands, thyroid cartilage, and glottic larynx. For all OARs, three endpoints were calculated: the Intraclass Correlation Coefficient (ICC), the Concordance Index (CI) and a 3D measure of variation (3D SD). RESULTS: All endpoints showed largest interobserver variability for the glottic larynx (ICC = 0.27, mean CI = 0.37 and 3D SD = 3.9 mm). Better agreement in delineations was observed for the other OARs (range, ICC = 0.32-0.83, mean CI = 0.64-0.71 and 3D SD = 0.9-2.6 mm). Cranial, caudal, and medial regions of the OARs showed largest variations. All endpoints provided support for improvement of delineation practice. CONCLUSIONS: Variation in delineation is traced to several regional causes. Measures to reduce this variation can be: (1) guideline development, (2) joint delineation review sessions and (3) application of multimodality imaging. Improvement of delineation practice is needed to standardize patient treatments.

mTHPC mediated interstitial photodynamic therapy of recurrent nonmetastatic base of tongue cancers: Development of a new method.

BACKGROUND: Interstitial photodynamic therapy (iPDT) can be an option in the management of locally recurrent base of tongue cancer after (chemo)radiation treatment. The purpose of the current study was to develop a technique to implant light sources into the tumor tissue. METHODS: Twenty patients with previously irradiated locally recurrent base of tongue cancers who were not candidates for salvage surgery or reirradiation or refused these therapies were included in this study. The treatment planning was done on MRI. The light sources were implanted using modified brachytherapy techniques. RESULTS: The iPDT could be conducted in all patients without short-term complications. At 6 months, 9 patients had complete response with 4 patients still free of disease (46-80 months). Long-term complications included pharyngocutaneous fistula in 6 patients, serious bleeding in 1 patient, and cutaneous metastasis in 2 patients. CONCLUSION: The initial results are encouraging. There is room for improvement to control the destructive potential of iPDT through planning and monitoring tools.

Predictive modelling for swallowing dysfunction after primary (chemo)radiation: results of a prospective observational study.

BACKGROUND AND PURPOSE: The purpose of this large multicentre prospective cohort study was to identify which dose volume histogram parameters and pre-treatment factors are most important to predict physician-rated and patient-rated radiation-induced swallowing dysfunction (RISD) in order to develop predictive models for RISD after curative (chemo) radiotherapy ((CH) RT). MATERIAL AND METHODS: The study population consisted of 354 consecutive head and neck cancer patients treated with (CH) RT. The primary endpoint was grade 2 or more swallowing dysfunction according to the RTOG/EORTC late radiation morbidity scoring criteria at 6 months after (CH) RT. The secondary endpoints were patient-rated swallowing complaints as assessed with the EORTC QLQ-H&N35 questionnaire. To select the most predictive variables a multivariate logistic regression analysis with bootstrapping was used. RESULTS: At 6 months after (CH) RT the bootstrapping procedure revealed that a model based on the mean dose to the superior pharyngeal constrictor muscle (PCM) and mean dose to the supraglottic larynx was most predictive. For the secondary endpoints different predictive models were found: for problems with swallowing liquids the most predictive factors were the mean dose to the supraglottic larynx and radiation technique (3D-CRT versus IMRT). For problems with swallowing soft food the mean dose to the middle PCM, age (18-65 versus >65 years), tumour site (naso/oropharynx versus other sites) and radiation technique (3D-CRT versus IMRT) were the most predictive factors. For problems with swallowing solid food the most predictive factors were the mean dose to the superior PCM, the mean dose to the supraglottic larynx and age (18-65 versus >65 years). And for choking when swallowing the V60 of the oesophageal inlet muscle and the mean dose to the supraglottic larynx were the most predictive factors. CONCLUSIONS: Physician-rated and patient-rated RISD in head and neck cancer patients treated with (CH) RT cannot be predicted with univariate relationships between the dose distribution in a single organ at risk and an endpoint. Separate predictive models are needed for different endpoints and factors other than dose volume histogram parameters are important as well.

Development of NTCP models for head and neck cancer patients treated with three-dimensional conformal radiotherapy for xerostomia and sticky saliva: the role of dosimetric and clinical factors.

PURPOSE: The purpose of this multicentre prospective study was to investigate the significance of the radiation dose in the major and minor salivary glands, and other pre-treatment and treatment factors, with regard to the development of patient-rated xerostomia and sticky saliva among head and neck cancer (HNC) patients treated with primary (chemo-) radiotherapy ((CH)RT). METHODS AND MATERIALS: The study population was composed of 167 consecutive HNC patients treated with three-dimensional conformal (3D-CRT) (CH) RT. The primary endpoint was moderate to severe xerostomia (XER6m) as assessed by the EORTC QLQ-H&N35 at 6 months after completing (CH)RT. The secondary endpoint was moderate to severe sticky saliva at 6 months (STIC6m). All organs at risk (OARs) potentially involved in salivary function were delineated on planning-CT, including the parotid, submandibular and sublingual glands and the minor glands in the soft palate, cheeks and lips. Patients with moderate to severe xerostomia or sticky saliva at baseline were excluded. The optimum number of variables for a multivariate logistic regression model was determined using a bootstrapping method. RESULTS: The multivariate analysis showed the mean parotid dose, age and baseline xerostomia (none versus a bit) to be the most important predictors for XER6m. The risk of developing xerostomia increased with age and was higher when minor baseline xerostomia was present in comparison with patients without any xerostomia complaints at baseline. Model performance was good with an area under the curve (AUC) of 0.82. For STIC6m, the mean submandibular dose, age, the mean sublingual dose and baseline sticky saliva (none versus a bit) were most predictive for sticky saliva. The risk of developing STIC6m increased with age and was higher when minor baseline sticky saliva was present in comparison with patients without any sticky saliva complaints at baseline. Model performance was good with an AUC of 0.84. CONCLUSIONS: Dose distributions in the minor salivary glands in patients receiving 3D-CRT have limited significance with regard to patient-rated symptoms related to salivary dysfunction. Besides the parotid and submandibular glands, only the sublingual glands were significantly associated with sticky saliva. In addition, reliable risk estimation also requires information from other factors such as age and baseline subjective scores. When these selected factors are included in predictive models, instead of only dose volume histogram parameters, model performance can be improved significantly.

Five-year follow-up of oral functioning and quality of life in patients with oral cancer with implant-retained mandibular overdentures.

BACKGROUND: The purpose of this prospective study was to assess the quality of life (QOL) and oral functioning of patients with oral cancer up to 5 years after prosthodontic rehabilitation with mandibular implant-retained overdentures. METHODS: Fifty patients who had received implants during ablative surgery were evaluated by standardized questionnaires before and after oncological and prosthetic treatment. RESULTS: In 20 of 24 surviving patients, the dentures were functional after 5 years. In these survivors, oral function remained unchanged during this period. In the 6 patients with concurrent comorbidity, global health and QOL had deteriorated, while in the patients without comorbidity, global health and QOL were very high. Five-year survivors had a higher global health and better oral functioning at the 1-year evaluation than nonsurvivors. CONCLUSION: Oral function and denture satisfaction were high and did not change over time for survivors. Deterioration in overall global health and QOL was associated with concurrent comorbidity.

Effect of radiotherapy and chemotherapy on bone marrow activity: a 18F-FLT-PET study.

BACKGROUND: Radiotherapy (RT) and chemotherapy are important treatment modalities for a variety of malignant tumor types. During therapy for malignant diseases, often the limitation for further therapy is determined by the capability of the bone marrow to withstand radiochemotherapeutic effects. Evaluation of hematologic toxicity is commonly performed with peripheral blood counts, and occasionally, sampling of marrow through a bone marrow biopsy. Neither method provides a comprehensive assessment, as bone marrow biopsy is invasive, and both are subject to sampling variability. Fluorine-18-3'-fluoro-3'-deoxy-L-thymidine-PET (18F-FLT-PET) is a noninvasive method and related to the rate of DNA synthesis and visualizes the high cycling activity of hematopoietic cells in the bone marrow compartment. To prove the clinical consistency of marrow function and imaging, we investigated populations of patients typically seen in clinical practice, after radiation and chemotherapy. In this feasibility study, patients were evaluated (i) to prove the ability of visualization and quantification of the activity of the bone marrow compartment with 18F-FLT-PET and (ii) to examine the effect of RT and chemotherapy on bone marrow activity and the correlation with clinical findings. METHODS: Bone marrow activity in the cervical region of 10 patients with laryngeal carcinoma who received a mean total dose of 68 Gy (range 30-41 fractions) was evaluated with 18F-FLT-PET, before and 1 month after RT. Whole body FLT images were assessed in nine patients with nonseminomatous testicular germ cell tumor, before and 6 months after the last chemotherapy, consisting of four courses of bleomycin, cisplatin, and etoposide. The maximum standardized uptake value (SUVmax) was used to quantify FLT uptake in bone marrow at the standard bone marrow regions. RESULTS: A significant decrease in 18F-FLT-PET uptake was observed in all the studied laryngeal carcinoma patients in the cervical region after RT of the adjacent bone marrow compartment. Tumor stage and additional field-of-view of RT were inversely related to the 18F-FLT uptake in bone marrow. The mean 18F-FLT SUVmax before RT was 3.0+/-1.34 and after RT was 1.94+/-0.60 (P=0.013). The mean 18F-FLT SUVmax of the spine (Th5-Th12) regions outside the field-of-view of RT were stable and reproducible and not significantly different (5.56+/-1.56 vs. 5.16+/-1.35, P=0.16). Chemotherapy did not result in a significant difference of whole body SUVmax value, with a mean SUVmax of 4.99+/-1.15 prechemotherapy, and a mean SUVmax of 5.28+/-1.0 postchemotherapy (P=0.21). Laboratory analysis of the hematologic parameters confirmed repopulation of the bone marrow. CONCLUSION: 18F-FLT uptake in the bone marrow decreases after RT, but not after chemotherapy. We conclude that 18F-FLT-PET is a potential noninvasive tool that can be used in the assessment of quantification of cellular division in the hematopoietic organ.

The Groningen Radiotherapy-Induced Xerostomia questionnaire: development and validation of a new questionnaire.

PURPOSE: The purpose of this study was to develop and validate a questionnaire (Groningen Radiotherapy-Induced Xerostomia (GRIX) questionnaire) that has the ability to distinguish between patient-rated xerostomia during day and night and can be used to evaluate the impact of emerging radiation delivery techniques aiming at prevention of xerostomia in more detail. MATERIALS AND METHODS: All questions in the GRIX were generated from an exhaustive list of relevant questions according to xerostomia as reported in the literature and reported by patients and health care providers. Finally the GRIX was reduced from 56 questions to a 14-item questionnaire, with four subscales; xerostomia during day and night and sticky saliva during day and night. 315 patients filled out 2936 questionnaires and the GRIX was evaluated by calculating Crohnbach's α for all subscales. Criterion validity was evaluated to compare the GRIX with patient-rated xerostomia scored with the EORTC QLQ-HN35 and physician-rated xerostomia, test-retest analysis and responsiveness were also tested. RESULTS: Crohnbach's α varied for all subscales between 0.88 and 0.94. The GRIX scored well for criterion-related validity on all subscales with high correlations with the EORTC QLQ-HN35 xerostomia and sticky saliva scale as well with physician-rated toxicity scoring. No significant differences were found between test and retest score and the GRIX showed good responsiveness with different time points for all subscales. CONCLUSION: The GRIX is a validated questionnaire which can be used in future research focusing on patient-rated xerostomia and sticky saliva during day and night in relation with the impact of emerging radiation delivery techniques aiming at reduction of xerostomia.

Enhanced proliferation of acinar and progenitor cells by prophylactic pilocarpine treatment underlies the observed amelioration of radiation injury to parotid glands.

BACKGROUND: Administration of pilocarpine before irradiation can ameliorate radiation-induced hyposalivation. Indirect evidence suggests that this effect may be mediated through induction of a compensatory response. In this study, this hypothesis is tested directly, by assessing the proliferation of progenitor and secretory cells in irradiated and non-irradiated parotid gland tissue. METHODS: In a rat model, parotid glands were unilaterally irradiated with a single dose of 15 Gy, 60 min after administration of pilocarpine (4.0mg/kg). Rats were sacrificed for proliferating cell nuclear antigen (PCNA) labelling, assessing the number of proliferating progenitor and secretory cells, before, and 10h, 1, 3, 7, 10, 20 and 30 days after irradiation. RESULTS: A small radiation-induced increase in PCNA expressing cells was observed, both in the acinar (secretory cells) and intercalated duct cell (containing the progenitor cells) compartment. This increment was significantly enhanced in pilocarpine pre-treated glands. In fact, in this group of animals increased proliferation was observed both in the irradiated and the shielded gland. CONCLUSIONS: Amelioration of early loss of rat salivary gland function after radiation by pilocarpine pre-treatment is, at least in part, due to compensatory mechanisms through increased proliferation of undamaged cells.

The prognostic role of comorbidity in salivary gland carcinoma.

BACKGROUND: Patients with head and neck cancer are prone to develop significant comorbidity mainly because of the high incidence of tobacco and alcohol abuse, both of which are etiologic and prognostic factors. However, to the authors' knowledge little is known regarding the prognostic relevance of comorbidity in patients with salivary gland cancer. METHODS: A retrospective cohort of 666 patients with salivary gland cancer was identified within the Dutch Head and Neck Oncology Cooperative Group database. For multivariate analysis, a Cox proportional hazards model was used to study the effect of comorbidity on overall survival and disease-specific survival. RESULTS: According to the Adult Comorbidity Evaluation-27 (ACE-27) index, 394 patients (64%) had grade 0 comorbidity, 119 patients (19%) had grade 1 comorbidity, 71 patients (12%) had grade 2 comorbidity, and 29 patients (5%) had grade 3 comorbidity. In multivariate analysis for overall survival, the ACE-27 comorbidity grade was a strong independent prognostic variable. The hazards ratio (HR) of death, including all causes, was 1.5 (95% confidence interval [CI], 1.1-2.1) for patients with ACE-27 grade 1 comorbidity versus grade 0 comorbidity (P < .007). The HR was 1.7 (95% CI, 1.2-2.5) for grade 2 comorbidity (P = .003) and 2.7 (95% CI, 1.5-4.7) for grade 3 comorbidity versus grade 0 comorbidity (P = .001). In the current analysis, ACE-27 comorbidity grade was not an independent prognostic factor for disease-free survival. CONCLUSIONS: To the authors' knowledge, this is the first study concerning the prevalence and relevance of the prognostic comorbidity variable ACE-27 grade in patients with salivary gland cancer. Overall survival, but not disease-free survival, was correlated strongly with ACE-27 grade. Compared with other studies that investigated the effect of comorbidity on patients with head and neck cancer, patients with salivary gland cancer had less comorbidity. Their comorbid status appeared to be reasonably comparable to that of patients with other nonsmoking- and nonalcohol-related cancers.

Protection of salivary function by concomitant pilocarpine during radiotherapy: a double-blind, randomized, placebo-controlled study.

PURPOSE: To investigate the effect of concomitant administration of pilocarpine during radiotherapy for head-and-neck squamous cell carcinoma (HNSCC) on postradiotherapy xerostomia. METHODS AND MATERIALS: A prospective, double blind, placebo-controlled randomized trial including 170 patients with HNSCC was executed to study the protective effect of pilocarpine on radiotherapy-induced parotid gland dysfunction. The primary objective endpoint was parotid flow rate complication probability (PFCP) scored 6 weeks, 6 months, and 12 months after radiotherapy. Secondary endpoints included Late Effects of Normal Tissue/Somatic Objective Management Analytic scale (LENT SOMA) and patient-rated xerostomia scores. For all parotid glands, dose-volume histograms were assessed because the dose distribution in the parotid glands is considered the most important prognostic factor with regard to radiation-induced salivary dysfunction. RESULTS: Although no significant differences in PFCP were found for the two treatments arms, a significant (p = 0.03) reduced loss of parotid flow 1 year after radiotherapy was observed in those patients who received pilocarpine and a mean parotid dose above 40 Gy. The LENT SOMA and patient-rated xerostomia scores showed similar trends toward less dryness-related complaints for the pilocarpine group. CONCLUSIONS: Concomitant administration of pilocarpine during radiotherapy did not improve the PFCP or LENT SOMA and patient-rated xerostomia scores. In a subgroup of patients with a mean dose above 40 Gy, pilocarpine administration resulted in sparing of parotid gland function. Therefore, pilocarpine could be provided to patients in whom sufficient sparing of the parotid is not achievable.

Patient position verification with oblique radiation beams.

PURPOSE: In this study we investigated whether the position of head and neck cancer patients during radiotherapy could be determined from portal images of oblique radiation beams. Currently applied additional anterior posterior (AP) and lateral verification beams could then be abandoned. METHOD: The patient position was determined from portal images of the oblique radiation beams and compared with that determined from AP and lateral verification beams. Seven hundred and fifty-one portal images of 18 different patients were analyzed. RESULTS: The set-up errors of patients that were treated with oblique gantry angles could be determined with the same accuracy from the oblique beams as from the AP and lateral verification beams in the ventrodorsal and craniocaudal direction. An additional AP beam was necessary to obtain the same accuracy in the lateral direction, because the used beam directions were relatively close to lateral. The position verification of patients treated with both oblique gantry angles and isocentric table rotations was more accurate if AP and lateral verification beams were used. CONCLUSIONS: For patients treated with an irradiation technique with oblique gantry angles (and no isocentric table rotations) position verification can be performed by using these oblique radiation beams.

Permanent unilateral hearing loss after radiotherapy for parotid gland tumors.

BACKGROUND: The purpose of this retrospective study was to determine the long-term effects of radiotherapy on hearing function in patients who underwent parotidectomy and postoperative radiotherapy for unilateral tumors of the parotid gland. METHODS: An extensive set of tests was used to measure hearing loss. The mean dose on middle ear, cochlea, and Eustachian tube was estimated with a CT-planning system. RESULTS: A hearing loss of > or = 15 dB in 3 frequencies was found in 32% of the 52 patients included in the study. Patients with an asymmetrical hearing loss received a higher mean dose on the hearing structures (p < .002). The threshold dose for clinically relevant hearing loss was found at 50 Gy on the cochlea and Eustachian tube. CONCLUSIONS: Radiation-induced hearing loss is a common complication. A mean dose of > 50 Gy on the cochlea should be avoided.

Variability of flow rate when collecting stimulated human parotid saliva.

The aim of this study was to estimate the accuracy and reproducibility of citric-acid-stimulated parotid saliva sampling. In healthy volunteers a strong correlation (r2 = 0.79) between flow rates from the left and right parotid gland was observed. In patients with Sjögren's syndrome this correlation (r2 = 0.90) was even stronger. The intraindividual variation in healthy volunteers was 23.3 +/- 5.9%. Increasing the number of collections did not reduce this variation significantly. In head and neck cancer patients, to estimate whether repeated measurements result in more reliable baseline values for use in clinical studies, repeated collections did not result in a significant reduction of intrapatient variation, similar to the results with the healthy volunteers. Thus, notwithstanding the good agreement between left and right flow rates, a high variation in parotid flow rates has to be considered when planning clinical trials evaluating the effects of treatment on salivary gland functioning.

Prevention and treatment of salivary gland hypofunction related to head and neck radiation therapy and chemotherapy.

Radiation therapy and chemotherapy for malignant tumors in the head and neck region are inevitably associated with injury to oral tissues, including the salivary glands. This often results in salivary gland hypofunction. Until now there has been no effective method of preventing damage caused by cancer therapies. Although not yet supported by sufficient evidence, there are some clinical trials indicating a potential benefit from radical scavengers and saliva stimulants. Other developments are in gene transfer to regain salivary gland function and stem cell transplantation to regenerate a diseased salivary gland. While irradiation on salivary gland tissue is irreversible to a large extent, hyposalivation associated with chemotherapy is usually less severe and reversible. In case of significant residual secretory capacity, supportive care is indicated. These patients are advised to stimulate their salivary glands by mechanical or gustatory stimuli. Alternatively, salivary flow can be stimulated by cholinergic stimulation (eg, pilocarpine or cevimeline). In the case of little or no residual capacity, palliative treatment is the only option. In such patients, nocturnal oral dryness can be alleviated by spraying oral surfaces with water or by applying a saliva substitute, particularly a substitute with gellike properties. During the day, the application of mouthwashes and saliva substitutes is indicated if moistening of oral surfaces with water is not sufficient. Recent developments are focusing on bioactive saliva substitutes and mouthwashes containing antimicrobial peptides to protect oral tissues against microbial colonization and to suppress or cure mucosal and gingival inflammation.

Supraomohyoid neck dissection in the management of cervical lymph node metastases of squamous cell carcinoma of the lower lip.

BACKGROUND: Supraomohyoid neck dissection (SOHND) is generally considered an adequate staging procedure in selected patients with squamous cell carcinoma (SCC) of the lip and oral cavity, with clinically negative nodes in the neck that are at increased risk for occult metastatic disease. The potential role of SOHND as a therapeutic surgical procedure for cervical metastasis limited to level I is controversial. METHODS: A series of 44 patients with clinical cervical lymph node metastases at level I from SCC of the lower lip is reported to evaluate the results of a treatment protocol consisting of therapeutic SOHND on indication followed by radiotherapy. RESULTS: Regional recurrences were observed in four (9%) patients. All recurrences developed within the SOHND dissected area only. CONCLUSIONS: A therapeutic SOHND, on indication followed by radiotherapy, can be an oncologically sound and effective procedure in the management of regional lymph node metastases at level I from SCC of the lower lip.