Laser treatment of 13 benign oral vascular lesions by three different surgical techniques

Objectives: Benign Oral Vascular Lesions (BOVLs) are a group of vascular diseases characterized by congenital, inflammatory or neoplastic vascular dilations clinically evidenced as more or less wide masses of commonly dark bluish color. If traumatized BOVLs are characterized by a great risk of hemorrhage and their treatment usually requires great caution to prevent massive bleeding. In the last decades lasers have dramatically changed the way of treatment of BOVLs permitting the application of even peculiar techniques that gave interesting advantages in their management reducing hemorrhage risks. The aim of this study was to evaluate the capabilities and disadvantages of three laser assisted techniques in the management of BOVLs. Study design: In this study 13 BOVLs were treated by three different laser techniques: the traditional excisional biopsy (EB), and two less invasive techniques, the transmucosal thermocoagulation (TMT) and the intralesional photocoagulation (ILP). Two different laser devices were adopted in the study: a KTP laser (DEKA, Florence, Italy, 532nm) and a GaAlAs laser (Laser Innovation, Castelgandolfo, Italy, 808nm) selected since their great effectiveness on hemoglobin. Results: In each case, lasers permitted safe treatments of BOVLs without hemorrhages, both during the intervention and in the post-operative period. The minimally invasive techniques (TMT and ILP) permitted even the safe resolution of big lesions without tissue loss. Conclusions: Laser devices confirm to be the gold standard in BOVLs treatment, permitting even the introduction of minimal invasive surgery principles and reducing the risks of hemorrhage typical of these neoplasms. As usual in laser surgery, it is necessary a clear knowledge of the devices and of the laser-tissue interaction to optimize the results reducing risks and disadvantages

Benign fibro-osseous lesions of the maxillas: analysis of 11 cases

Introduction: A study is made of the principal characteristics of the oral lesions biopsied in our Service of Oral Surgery and histologically diagnosed as corresponding to fibro-osseous lesions of the maxillas. Patients and methods: A retrospective review was made of all the biopsies made in a Service of Oral Surgery between 1996 and 2003. The reason for consultation was analyzed, along with patient age, sex, clinical and radiological characteristics, tentative diagnosis, histological diagnosis and treatment provided. Results: A total of 1238 biopsies were performed during the study period. Of these, only 11 corresponded to benign fibro-osseous lesions (7 women and 4 men). The mean patient age was 44 years (range 19-72 years). The most frequent location was the mandible (8 of the cases). In 7 patients the lesions constituted casual radiological findings; 4 presented bulging of the vestibular cortical bone, though only one of them reported pain. The histological diagnoses comprised 7 cemento-ossifying fibromas and 4 fibrous dysplasias. In 9 cases surgical resection was carried out, while in one case an incisional biopsy was performed, and in the remaining case curettage was decided. Discussion: These lesions are more frequent in women than in men, and the age at presentation is variable. In terms of lesion location, fibrous dysplasia is more common in the upper maxilla, while cemento-ossifying fibroma is more frequently found in the mandible. The diagnosis of such lesions is established upon contrasting the data obtained from the anamnesis, physical examination, the radiological characteristics, the intraoperative findings and the histological study, since both disorders have similar clinical and histological features- despite the fact that they constitute distinct disease conditions.

Central odontogenic fibroma: retrospective study of 8 clinical cases

Introduction and Objectives: The central odontogenic fibroma (COF) is a benign odontogenic tumour derived from the dental mesenchymal tissues. It is a rare tumour and only 70 cases of it have been published. Bearing in mind the rareness of the tumour, 8 new cases of central odontogenic fibroma have been found by analyzing the clinical, radiological and histopathological characteristics of COF. Patients and Method: A retrospective study was carried out on 3011 biopsies in the Service of Oral and Maxillofacial Surgery of the Dental Clinic of Barcelona University between January 1995 and March 2008. 85 odontogenic tumours were diagnosed of which 8 were central odontogenic fibroma. The radiological study was based on orthopantomographs, periapical and occlusal radiographies and computerised tomographics. The variables collected were: sex, age, clinical characteristics of the lesion, treatment received and possible reappearances of the tumour. Results: The central odontogenic fibroma represents 9.4% of all odontogenic tumours. Of the 8 cases, 5 were diagnosed in men and 3 in women. The average age was 19.9 years with an age range of 11 to 38 years. The most common location of the tumour was in the mandible. All cases were associated with unerupted teeth. Of the 8 tumours, 3 provoked rhizolysis of the adjacent teeth and 4 cases caused cortical bone expansion. 50% of the patients complained of pain associated to the lesion. No case of recurrence was recorded up to 2 years after the treatment. Conclusions: Central odontogenic fibromas usually evolve asymptomatically although they can manifest very aggressively provoking dental displacement and rhizolysis. Radiologically, COF manifest as a uni or multilocular radiotransparent image although they can be indistinguishable from other radiotransparent lesions making diagnosis more difficult. COF treatment involves conservative surgery as well as follow-up patient checks.

Risk Prediction Scores for Recurrence and Progression of Non-Muscle Invasive Bladder Cancer: An International Validation in Primary Tumours

Abstract Objective: We aimed to determine the validity of two risk scores for patients with non-muscle invasive bladder cancer in different European settings, in patients with primary tumours. Methods: We included 1,892 patients with primary stage Ta or T1 non-muscle invasive bladder cancer who underwent a transurethral resection in Spain (n = 973), the Netherlands (n = 639), or Denmark (n = 280). We evaluated recurrence-free survival and progression-free survival according to the European Organisation for Research and Treatment of Cancer (EORTC) and the Spanish Urological Club for Oncological Treatment (CUETO) risk scores for each patient and used the concordance index (c-index) to indicate discriminative ability. Results: The 3 cohorts were comparable according to age and sex, but patients from Denmark had a larger proportion of patients with the high stage and grade at diagnosis (p,0.01). At least one recurrence occurred in 839 (44%) patients and 258 (14%) patients had a progression during a median follow-up of 74 months. Patients from Denmark had the highest 10- year recurrence and progression rates (75% and 24%, respectively), whereas patients from Spain had the lowest rates (34% and 10%, respectively). The EORTC and CUETO risk scores both predicted progression better than recurrence with c-indices ranging from 0.72 to 0.82 while for recurrence, those ranged from 0.55 to 0.61. Conclusion: The EORTC and CUETO risk scores can reasonably predict progression, while prediction of recurrence is more difficult. New prognostic markers are needed to better predict recurrence of tumours in primary non-muscle invasive bladder cancer patients.

O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction

Background: The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) confers resistance to alkylating agents. Several methods have been applied to its analysis, with methylation-specific polymerase chain reaction (MSP) the most commonly used for promoter methylation study, while immunohistochemistry (IHC) has become the most frequently used for the detection of MGMT protein expression. Agreement on the best and most reliable technique for evaluating MGMT status remains unsettled. The aim of this study was to perform a systematic review and meta-analysis of the correlation between IHC and MSP. Methods A computer-aided search of MEDLINE (1950-October 2009), EBSCO (1966-October 2009) and EMBASE (1974-October 2009) was performed for relevant publications. Studies meeting inclusion criteria were those comparing MGMT protein expression by IHC with MGMT promoter methylation by MSP in the same cohort of patients. Methodological quality was assessed by using the QUADAS and STARD instruments. Previously published guidelines were followed for meta-analysis performance. Results Of 254 studies identified as eligible for full-text review, 52 (20.5%) met the inclusion criteria. The review showed that results of MGMT protein expression by IHC are not in close agreement with those obtained with MSP. Moreover, type of tumour (primary brain tumour vs others) was an independent covariate of accuracy estimates in the meta-regression analysis beyond the cut-off value. Conclusions Protein expression assessed by IHC alone fails to reflect the promoter methylation status of MGMT. Thus, in attempts at clinical diagnosis the two methods seem to select different groups of patients and should not be used interchangeably.

Classifier combination for in vivo magnetic resonance spectra of brain tumours

Peer-reviewed

Classifier combination for in vivo magnetic resonance spectra of brain tumours

In this paper we present a multi-stage classifier for magnetic resonance spectra of human brain tumours which is being developed as part of a decision support system for radiologists. The basic idea is to decompose a complex classification scheme into a sequence of classifiers, each specialising in different classes of tumours and trying to reproducepart of the WHO classification hierarchy. Each stage uses a particular set of classification features, which are selected using a combination of classical statistical analysis, splitting performance and previous knowledge.Classifiers with different behaviour are combined using a simple voting scheme in order to extract different error patterns: LDA, decision trees and the k-NN classifier. A special label named "unknown¿ is used when the outcomes of the different classifiers disagree. Cascading is alsoused to incorporate class distances computed using LDA into decision trees. Both cascading and voting are effective tools to improve classification accuracy. Experiments also show that it is possible to extract useful information from the classification process itself in order to helpusers (clinicians and radiologists) to make more accurate predictions and reduce the number of possible classification mistakes.