Recommendations for intraoperative mesh brachytherapy: Report of AAPM Task Group No. 222.

Mesh brachytherapy is a special type of a permanent brachytherapy implant: it uses low-energy radioactive seeds in an absorbable mesh that is sutured onto the tumor bed immediately after a surgical resection. This treatment offers low additional risk to the patient as the implant procedure is carried out as part of the tumor resection surgery. Mesh brachytherapy utilizes identification of the tumor bed through direct visual evaluation during surgery or medical imaging following surgery through radiographic imaging of radio-opaque markers within the sources located on the tumor bed. Thus, mesh brachytherapy is customizable for individual patients. Mesh brachytherapy is an intraoperative procedure involving mesh implantation and potentially real-time treatment planning while the patient is under general anesthesia. The procedure is multidisciplinary and requires the complex coordination of multiple medical specialties. The preimplant dosimetry calculation can be performed days beforehand or expediently in the operating room with the use of lookup tables. In this report, the guidelines of American Association of Physicists in Medicine (AAPM) are presented on the physics aspects of mesh brachytherapy. It describes the selection of radioactive sources, design and preparation of the mesh, preimplant treatment planning using a Task Group (TG) 43-based lookup table, and postimplant dosimetric evaluation using the TG-43 formalism or advanced algorithms. It introduces quality metrics for the mesh implant and presents an example of a risk analysis based on the AAPM TG-100 report. Recommendations include that the preimplant treatment plan be based upon the TG-43 dose calculation formalism with the point source approximation, and the postimplant dosimetric evaluation be performed by using either the TG-43 approach, or preferably the newer model-based algorithms (viz., TG-186 report) if available to account for effects of material heterogeneities. To comply with the written directive and regulations governing the medical use of radionuclides, this report recommends that the prescription and written directive be based upon the implanted source strength, not target-volume dose coverage. The dose delivered by mesh implants can vary and depends upon multiple factors, such as postsurgery recovery and distortions in the implant shape over time. For the sake of consistency necessary for outcome analysis, prescriptions based on the lookup table (with selection of the intended dose, depth, and treatment area) are recommended, but the use of more advanced techniques that can account for real situations, such as material heterogeneities, implant geometric perturbations, and changes in source orientations, is encouraged in the dosimetric evaluation. The clinical workflow, logistics, and precautions are also presented.

Surface brachytherapy: Joint report of the AAPM and the GEC-ESTRO Task Group No. 253.

The surface brachytherapy Task Group report number 253 discusses the common treatment modalities and applicators typically used to treat lesions on the body surface. Details of commissioning and calibration of the applicators and systems are discussed and examples are given for a risk-based analysis approach to the quality assurance measures that are necessary to consider when establishing a surface brachytherapy program.

Electronic intracavitary brachytherapy quality management based on risk analysis: The report of AAPM TG 182.

PURPOSE: The purpose of this study was to provide guidance on quality management for electronic brachytherapy. MATERIALS AND METHODS: The task group used the risk-assessment approach of Task Group 100 of the American Association of Physicists in Medicine. Because the quality management program for a device is intimately tied to the procedure in which it is used, the task group first designed quality interventions for intracavitary brachytherapy for both commercial electronic brachytherapy units in the setting of accelerated partial-breast irradiation. To demonstrate the methodology to extend an existing risk analysis for a different application, the task group modified the analysis for the case of post-hysterectomy, vaginal cuff irradiation for one of the devices. RESULTS: The analysis illustrated how the TG-100 methodology can lead to interventions to reduce risks and improve quality for each unit and procedure addressed. CONCLUSION: This report provides a model to guide facilities establishing a quality management program for electronic brachytherapy.

Neutrophil elastase levels in the gingival crevicular fluid following hyaluronan gel application in the treatment of chronic periodontitis: A randomized split-mouth study.

BACKGROUND: Neutrophils are the predominant leukocytes in the periodontium, which prevent infection from periodontal pathogens and subsequent tissue destruction. A potentially destructive role has been elucidated, especially due to elastase enzyme. Controlling its levels might be crucial in minimizing the tissue destruction. Hyaluronan, known to inhibit the release of this enzyme from neutrophils, might be a viable option to treat chronic periodontitis. AIMS: The aim of this study is to evaluate and compare the effects of 0.2% hyaluronan gel adjunctive to scaling and root planing on the levels of elastase in gingival crevicular fluid (GCF). SETTINGS AND DESIGN: This split-mouth study included eighty (forty experimental and forty control) sites from twenty patients representing both sexes. MATERIALS AND METHODS: GCF samples were collected from all the eighty sites; simultaneously, clinical periodontal parameters were recorded. Enzyme-linked immunosorbent assay was used to determine the levels of elastase at baseline and 6 weeks after therapy, following mechanical debridement and subsequent subgingival placement of the experimental drug. STATISTICAL ANALYSIS USED: With the aid of statistical software (SPSS Version 13), Student's t-test and Pearson's correlation test were performed. RESULTS: There was a mean reduction in the elastase levels from baseline to 6 weeks after therapy in the experimental group. However, the difference between the groups was not statistically significant. CONCLUSIONS: Adjunctive use of hyaluronan following mechanical debridement resulted in comparable reduction in the elastase levels, suggesting that this substance has an inhibitory effect on elastase, and subsequent tissue destruction. Further long-term studies are mandatory to validate the results of this study.

Aspects of dosimetry and clinical practice of skin brachytherapy: The American Brachytherapy Society working group report.

PURPOSE: Nonmelanoma skin cancers (NMSCs) are the most common type of human malignancy. Although surgical techniques are the standard treatment, radiation therapy using photons, electrons, and brachytherapy (BT) (radionuclide-based and electronic) has been an important mode of treatment in specific clinical situations. The purpose of this work is to provide a clinical and dosimetric summary of the use of BT for the treatment of NMSC and to describe the different BT approaches used in treating cutaneous malignancies. METHODS AND MATERIALS: A group of experts from the fields of radiation oncology, medical physics, and dermatology, who specialize in managing cutaneous malignancies reviewed the literature and compiled their clinical experience regarding the clinical and dosimetric aspects of skin BT. RESULTS: A dosimetric and clinical review of both high dose rate ((192)Ir) and electronic BT treatment including surface, interstitial, and custom mold applicators is given. Patient evaluation tools such as staging, imaging, and patient selection criteria are discussed. Guidelines for clinical and dosimetric planning, appropriate margin delineation, and applicator selection are suggested. Dose prescription and dose fractionation schedules, as well as prescription depth are discussed. Commissioning and quality assurance requirements are also outlined. CONCLUSIONS: Given the limited published data for skin BT, this article is a summary of the limited literature and best practices currently in use for the treatment of NMSC.

A randomized clinical trial of autologous platelet-rich plasma in the treatment of mandibular degree II furcation defects.

AIM: A combined technique using a platelet-rich plasma (PRP)/bovine porous bone mineral/guided tissue regeneration membrane was found to be an effective modality for the treatment of mandibular grade II furcation defects. To elucidate the role played by each component, the present randomized, double-blind study is designed to evaluate the effectiveness of autologous PRP alone in the treatment of mandibular degree II furcation defects compared with open flap debridement (OFD). MATERIAL AND METHODS: Using a split-mouth design, 40 mandibular degree II furcation defects were treated either with autologous PRP or OFD. Plaque index, sulcus bleeding index, vertical probing depth, relative vertical and horizontal clinical attachment level and gingival marginal level were recorded at baseline and 6 months post-operatively. Vertical and horizontal defect depths were also recorded using spiral computed tomography. RESULTS: A statistically significant difference was observed in all the clinical and radiographic parameters at the sites treated with PRP as compared with those with OFD. However, all the furcation defects retained their degree II status. CONCLUSION: Despite a significant improvement, lack of complete closure of furcation defects implies a limited role of autologous PRP as a regenerative material in the treatment of furcation defects, necessitating further long-term studies.

Clinical effectiveness of autologous platelet-rich plasma and Peptide-enhanced bone graft in the treatment of intrabony defects.

BACKGROUND: The goal of periodontal therapy has always been the regeneration of lost attachment apparatus. The use of platelet-rich plasma (PRP) plus anorganic bovine-derived matrix and peptide 15 (ABM/P-15) for periodontal regenerative therapy offers a potentially useful modality for treating periodontal osseous defects. However, it is unknown whether a combination of these materials enhances the outcome of periodontal regenerative therapy. Therefore, this study was carried out to compare the effectiveness of the two regenerative techniques (autologous PRP plus ABM/P-15 versus autologous PRP) in treating intrabony defects in humans by analyzing the clinical and radiologic parameters. METHODS: Using a split-mouth design, 28 intrabony defects were treated with autologous PRP (control) or a combination of autologous PRP and ABM/P-15 (test). Clinical parameters such as plaque index, sulcus bleeding index, probing depth, attachment level, and gingival marginal level were recorded at baseline and 9 months postoperatively. Hard tissue measurements such as defect fill, defect resolution, and change in alveolar crest height were also recorded using spiral computed tomography (CT). RESULTS: A statistically significant difference was observed in all clinical parameters in the test group compared to the control group. Furthermore, spiral CT images revealed significantly greater bone fill in the test group. CONCLUSIONS: A combination of PRP plus ABM/P-15 was more effective than PRP alone in the treatment of intrabony defects. Further studies using a larger sample size are necessary to confirm the results of the present study.

Papillon-Lefèvre syndrome: a case report.

We present a case of Papillon-Lefèvre syndrome in an 8-year-old child. The syndrome is characterized by periodontal disease affecting the deciduous and permanent dentition, along with palmar and plantar keratosis. Other symptoms include increased susceptibility to infections. Family history revealed consanguinity and similar findings in her two siblings. A review of several reports describe successful outcomes in a few patients, which suggests it may be possible to halt the periodontal disease process if one uses a combined and intensive mechanical and antimicrobial treatment approach in these patients.

TG-69: radiographic film for megavoltage beam dosimetry.

TG-69 is a task group report of the AAPM on the use of radiographic film for dosimetry. Radiographic films have been used for radiation dosimetry since the discovery of x-rays and have become an integral part of dose verification for both routine quality assurance and for complex treatments such as soft wedges (dynamic and virtual), intensity modulated radiation therapy (IMRT), image guided radiation therapy (IGRT), and small field dosimetry like stereotactic radiosurgery. Film is convenient to use, spatially accurate, and provides a permanent record of the integrated two dimensional dose distributions. However, there are several challenges to obtaining high quality dosimetric results with film, namely, the dependence of optical density on photon energy, field size, depth, film batch sensitivity differences, film orientation, processing conditions, and scanner performance. Prior to the clinical implementation of a film dosimetry program, the film, processor, and scanner need to be tested to characterize them with respect to these variables. Also, the physicist must understand the basic characteristics of all components of film dosimetry systems. The primary mission of this task group report is to provide guidelines for film selection, irradiation, processing, scanning, and interpretation to allow the physicist to accurately and precisely measure dose with film. Additionally, we present the basic principles and characteristics of film, processors, and scanners. Procedural recommendations are made for each of the steps required for film dosimetry and guidance is given regarding expected levels of accuracy. Finally, some clinical applications of film dosimetry are discussed.