Intensity-modulated radiotherapy of nasopharyngeal carcinoma: a comparative treatment planning study of photons and protons

<p>Abstract</p> <p>Background</p> <p>The aim of this treatment planning study was to investigate the potential advantages of intensity-modulated (IM) proton therapy (IMPT) compared with IM photon therapy (IMRT) in nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Eight NPC patients were chosen. The dose prescriptions in cobalt Gray equivalent (Gy_E) for gross tumor volumes of the primary tumor (GTV-T), planning target volumes of GTV-T and metastatic (PTV-TN) and elective (PTV-N) lymph node stations were 72.6 Gy_E, 66 Gy_E, and 52.8 Gy_E, respectively. For each patient, nine coplanar fields IMRT with step-and-shoot technique and 3D spot-scanned three coplanar fields IMPT plans were prepared. Both modalities were planned in 33 fractions to be delivered with a simultaneous integrated boost technique. All plans were prepared and optimized by using the research version of the inverse treatment planning system KonRad (DKFZ, Heidelberg).</p> <p>Results</p> <p>Both treatment techniques were equal in terms of averaged mean dose to target volumes. IMPT plans significantly improved the tumor coverage and conformation (<it>P </it>< 0.05) and they reduced the averaged mean dose to several organs at risk (OARs) by a factor of 2–3. The low-to-medium dose volumes (0.33–13.2 Gy_E) were more than doubled by IMRT plans.</p> <p>Conclusion</p> <p>In radiotherapy of NPC patients, three-field IMPT has greater potential than nine-field IMRT with respect to tumor coverage and reduction of the integral dose to OARs and non-specific normal tissues. The practicality of IMPT in NPC deserves further exploration when this technique becomes available on wider clinical scale.</p

Current treatment options for recurrent nasopharyngeal cancer

Loco-regional control rate of nasopharyngeal carcinoma (NPC) has improved significantly in the past decade. However, local recurrence still represents a major cause of mortality and morbidity in advanced stages, and management of local failure remains a challenging issue in NPC. The best salvage treatment for local recurrent NPC remains to be determined. The options include brachytherapy, external radiotherapy, stereotactic radiosurgery, and nasopharyngectomy, either alone or in different combinations. In this article we will discuss the different options for salvage of locally recurrent NPC. Retreatment of locally recurrent NPC using radiotherapy, alone or in combination with other treatment modalities, as well as surgery, can result in long-term local control and survival in a substantial proportion of patients. For small-volume recurrent tumors (T1–T2) treated with external radiotherapy, brachytherapy or stereotactic radiosurgery, comparable results to those obtained with surgery have been reported. In contrast, treatment results of advanced-stage locally recurrent NPC are generally more satisfactory with surgery (with or without postoperative radiotherapy) than with reirradiation

Assessment of the quality of measures of child oral health-related quality of life

Background Several measures of oral health-related quality of life have been developed for children. The most frequently used are the Child Perceptions Questionnaire (CPQ), the Child Oral Impacts on Daily Performances (C-OIDP) and the Child Oral Health Impact Profile (COHIP). The aim of this study was to assess the methodological quality of the development and testing of these three measures. Methods A systematic search strategy was used to identify eligible studies published up to December 2012, using both MEDLINE and Web of Science. Titles and abstracts were read independently by two investigators and full papers retrieved where the inclusion criteria were met. Data were extracted by two teams of two investigators using a piloted protocol. The data were used to describe the development of the measures and their use against existing criteria. The methodological quality and measurement properties of the measures were assessed using standards proposed by the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) group. Results The search strategy yielded 653 papers, of which 417 were duplicates. Following analysis of the abstracts, 119 papers met the inclusion criteria. The majority of papers reported cross-sectional studies (n = 117) with three of longitudinal design. Fifteen studies which had used the original version of the measures in their original language were included in the COSMIN analysis. The most frequently used measure was the CPQ. Reliability and construct validity appear to be adequate for all three measures. Children were not fully involved in item generation which may compromise their content validity. Internal consistency was measured using classic test theory with no evidence of modern psychometric techniques being used to test unidimensionality of the measures included in the COSMIN analysis. Conclusion The three measures evaluated appear to be able to discriminate between groups. CPQ has been most widely tested and several versions are available. COHIP employed a rigorous development strategy but has been tested in fewer populations. C-OIDP is shorter and has been used successfully in epidemiological studies. Further testing using modern psychometric techniques such as item response theory is recommended. Future developments should also focus on the development of measures which can evaluate longitudinal change

Root Conditioning and Agents Effect in Regeneration of Periodontal Tissue

Periodontitis affected root surfaces are hypermineralized and contaminated with cytotoxic and&quot;nother biologically active substances.&quot;nThe instrumented surface will inervitably be coverd by a smear layer following root planing with or without flap.&quot;nSmear layer is resistant to saline rinsing, but may be removed with agents such as acids (e.g.citric acid), tetracyclines, EDTA, and laser.&quot;nLow pH aqueous solutions such as citric acid have been used in surgical periodontal therapy mainly for two reasons, It dissolves smear layer after a relatively short exposure time and it has been claimed to selectively remove root surface associated mineral exposing collagen to varying degrees. A root surface coated with collagen appears to be a preferred surface for fibroblast attachment, a cellular event fundamental to successful periodontal wound healing.&quot;nSeveral studies indicate the potential of tetracycline (TTE-HCL) in periodontal regeneration. Its acidic pH suggest that it can be used as a demineralization agent and removing the smear layer and exposing collagen matrix of the dentin.&quot;nChalating agent (EDTA) working at neutral pH appears preferable with respect to preserving the integrity of exposed collagen fibers, early colonization, and wound healing. In addition, etching at neutral pH has been reported preserve adjacent tissue- vitality, while etching at low pH necrotizes the fiap and adjacent periodontium.&quot;nClinical and subclinical studies have demonstrated laser waves can remove calculus and bacterial plaque and pocket epithelium and strile the root surface and can expose the dentin collagen and dentinal tublules, and leads to pronounce reducing of probing depth around teeth diseased with periodontitis

Comparison of right-handed and left-handed dental students in measurement of periodontal pocket depth

&quot;nBackground and Aims: The precision of periodontal pocket measurements with periodontal probe is related to different factors. Some of these are related to examiner. The purpose of this study was to compare the right-handed and left-handed dental students in the measurement of periodontal pocket depth (PPD).&quot;nMaterials and Methods: Eight systemically healthy adult patients (mean age of 35 years) with 0.5-6 mm periodontal pocket depth and a minimum of 20 teeth were examined by 4 right-handed and 4 left-handed students of dentistry (mean age of 25 years). These students were trained for periodontal examination probe depth measurements with Williams probe. Measurements were inserted in SPSS software and analyzed with Iintraclass correlation coefficient (ICCS) and T-test.&quot;nResults: There was statistically significant difference in the measurement of PPD between right-handed and left-handed examiners in the whole mouth (P&amp;lt;0.05), but this difference (0.08 mm) was not clinically significant. The most difference was found in the posterior teeth of mandible at right quadrant (mean=0.2 mm). Analyses of each pair of same handed and different handed examiners with T-test and ICCS showed that these measurements were nearly similar and reproducible.&quot;nConclusion: There was no clinically significant difference in measurement of PPD between right-handed and left-handed examiners

A survey on the effects of Azithromycin in the treatment of gingival overgrowth induced by Cyclosporin in renal transplant patients

Statement of Problem: Gingival overgrowth is a side effect commonly induced by Cyclosporin treatment. The effects of Azithromycin, a macrolidic antibiotic, has been focused on gingival enlargement treatment induced by cyclosporine in numerous articles. Purpose: The goal of the present study was to survey the effects of systemic Azithromycin in the treatment of gingival overgrowth induced by cyclosporine among renal transplant patients. Materials and Methods: In this clinical trial study, 18 renal transplant patients (6 females and 12 males) with gingival overgrowth were studied. Samples were randomly divided into two groups: case group were treated by systemic Azithromycin and controls were treated by systemic placebo. Periodontal parameters including bleeding on probing (BOP), clinical crown length (CL), periodontal pocket depth (PPD), gingival overgrowth (GOI) and stent-IDP (vertical distant between a stent or plate with teeth occlusal planes at least from three of the most anterior contact points to mesial papillae) before treatment, two and six weeks after treatment were measured. To analyze the data, Wilcoxon and Mann-Whitney tests were used. Results: Most of the measured indices, among case and control groups, were significantly improved, after two weeks (P&lt;0.05). No statistically significant differences were found between two groups except for BOP index (P&lt;0.05). In other words, more BOP improvement was observed in the case group after six weeks comparing to the control group. Conclusion: Considering the findings of this study, one can assume that the reported effects of Azithromycine on gingival overgrowth, induced by cyclosporine is somehow exaggerated and the effects attributed this medicine is probably inflammation reduction

Nonsurgical treatments in periodontics

Both surgical and nonsurgical treatments are definitely effective in ameliorating periodontal condition. In nonsurgical treatments, pocket elimination is not an essential part but subgingival infection control is the main objective which can eliminate inflammation, stop destruction, form new attachments, decrease pocket depth (following edema decrease) and finally result in long junctional epithelium formation. In short term, surgery can eliminate pocket depth more effectively although after a while this difference would become less. Besides, nowadays according to infectious nature of periodontal diseases systemic and local antimicrobials are used along with nonsurgical and mechanical treatments specially in rapidly progressing periodontitis, HIV related periodontitis and refractory periodontitis . Therefore, the most appropriate and simplest treatment plan should be selected according to the type of periodontal disease

INVESTIGATION OF PERIODONTITIS PATIENTS AND COMPARISON WITH CONTROL GROUP

The bacterial population found in the gingival sulcus region in periodontitis consists of gram negative microorganisms; most of them are obligate anaerobes and capnophil, including Porphyromonas, Prevotella, Fusobaclenuin, Welinella, Actinobacillus actinomycetem comitans, Eiknella and Capnocytohaga. This study has been carried out to investigate anaerobic and capnophilic bacteria from 206 specimens of patients with periodontitis and 145 specimens of control group. Different bacteria isolated from total specimens were obtained as follows: Actinobacillus actinomycetem comitans (patients group 36.9%, control group 4.1 %), Capnocytophaga (47.9%), Eikenella corodens (34.5% , 10.3%), Porphyryromonas gingivaIis (35% , 11%), Prevotella intermedius25.7%, 6.7%) and Prevotella melaninogenicus (13.6% , 3.4%)

Isolation and characterization of oral Actinomyces strain from patients with periodontal disease

&quot;nAbstract: Actinomyces species are normal residents of the mouth cavity, gastrointestinal tract and female genital tract. The genus consists of gram-positive bacteria, strictly anaerobic or microaerophilic. The bacteria are opportunists with a low virulence potential that cause actinomycosis only when the normal mucosal barriers are disrupted. The main purpose of this study was the isolation of Actinomyces strains and determining of their role in periodontal diseases. The present study was carried out on 100 patients with periodontal diseases referred to the Periodontic Department of Faculty of Dentistry. The sampling was done in 6 months with isolation of oral Actinomyces from microbial plaque and periodontal pocket. The samples were selected based on the following criteria: periodontal plaque with deep pocket (&amp;gt;3 mm), no antibiotic therapy for a period of at least two weeks, and lack of systemic diseases. One strain of Actinomyces viscosus and two strains of Actinomyces naeslundii were isolated from the patients with gingivitis and periodontitis. Of the 100 patients with gingivitis and periodontitis, aged between 18-57 years old, 46% were males and 54% were females. The peak incidence of the diseases (35%) was in the third age group (31-40) and the lowest incidence (10%) was in the first age group (&amp;lt;20). Forty patients (40%) complained of gingival disease and its bleeding with lower incidence of (42.5%) in female

STUDY OF RELATIONSHIP BETWEEN DEPTH OF PERIODONTAL POCKETS, ANAEROBIC BACTERIA AND INFLAMMATORY CELLS IN PERIODONTITIS

In this study 100 cases of advanced periodontitis were compared with a control group of 100 persons. The parameters were the depth of the periodontal pockets, radiographic images, presence of inflammatory cells and different types of anaerobic bacteria in the pockets. The depth of pocket was measured by a sterile probe and the presence of inflammatory cells was determined through sterile curettage. The smears were stained by Gimsa and Gram methods. For the purpose of microbiological studies, subgingival plaque samples were taken on paper points and were plated on brucella agar medium supplemented with rabbit blood, haemin and vitamin K1. The results indicated that with increasing depth of the pocket, the number of mixed anaerobic infections increases, and the presence of inflammatory cells especially polymorphonuclears is more prominent in comparison to the control group. As the pocket depth increases the conditions become more favourable for anaerobic bacteria and in consequence the incidence of isolation of these bacteria increases. On the other hand as the number of anaerobic bacteria and inflammatory cells and the secretion of destructive enzymes increases, the resultant injury to periodontal tissue increases