Radiotherapy in larynx squamous cell carcinoma is not associated with an increased diagnosis of second primary tumours.

AIMS: Larynx cancer is the most common form of head and neck squamous cell carcinoma (HNSCC). Radiotherapy is a major treatment modality and is implicated in the possible formation of second primary tumours (SPT). The aims of this retrospective study were to establish the incidence of SPTs and their correlation with previous radiotherapy and to establish overall survival and the SPT diagnostic time lag from the index tumour according to subtype as well as radiotherapy status. MATERIALS AND METHODS: In a retrospective study of 987 patients with larynx SCCs (1967-2004) associations between radiotherapy, diagnosis of SPTs, median SPT diagnostic time lag, disease-free survival and overall survival were analysed. RESULTS: In total, 184 (18.6%) patients developed metachronous SPTs with an overall survival of 93.0 (standard error 6.8 months). One hundred and seventy (92.4%) underwent radiotherapy, whereas 14 (7.6%) patients were not exposed to radiotherapy. No significant increased incidence of SPT was shown in the radiotherapy group. A statistically non-significant increase in SPT diagnostic time lag trend was noted for both HNSCC SPTs (radiotherapy vs non-radiotherapy; 76.0 [standard error 6.7] vs 50.0 [standard error 23.0]) and lung SPTs (45.0 [standard error 12.1] vs 24.0 [standard error 4.9]) months. CONCLUSION: This study suggests that radiotherapy is not a risk for SPT induction; it may, however, neutralise a proportion of cancerised fields in the lung and head and neck areas without any significant benefit on overall survival.

Effect of distraction rate on biomechanical, mineralization, and histologic properties of an ovine mandible model.

Craniofacial microsomia is a common congenital malformation. Ilizarov's method of distraction osteogenesis applied to the mandible has yielded promising results both experimentally and clinically. Because the technique is used predominantly in a pediatric population, length of treatment and compliance may be problematic. To date, the limits of distraction rate in the craniofacial skeleton have not been defined. This study was designed to investigate the effects of distraction rate, in a large animal model, on the mineralization, biomechanical, and histologic properties of lengthened mandibles. Clinically faster distraction rates would decrease the overall treatment time. Twenty-four animals were divided into four groups, with varying rates of distraction (1, 2, 3, and 4 mm/day). A uniaxial distractor at the angle of the mandible was used. The mandibles were lengthened to 24 mm and fixed for a period of 5 weeks, when the animals were killed. The specimens were analyzed with respect to mineralization using dual energy x-ray absorptiometry, biomechanical strength, through a modified three-point bending test, and histologic properties with hematoxylin and eosin stains. Biomechanical, mineralization, and histologic analyses of the samples indicated that group 1 (1 mm/day) samples were significantly superior (p<0.05) to those of group 4 (4 mm/day). Although bone formation was achieved in all groups, group 1 (1 mm/day) demonstrated the strongest biomechanical and histologic properties. Bone mineral density obtained using dual energy x-ray absorptiometry may be clinically useful as a reliable, noninvasive, and relatively cheap predictor for removal time of the fixator.

Autologous microtia reconstruction combined with ancillary procedures: a comprehensive reconstructive approach.

INTRODUCTION: Autologous microtia reconstruction is generally performed in two stages. The second stage presents a unique opportunity to carry out other complementary procedures. The present study describes our approach to microtia reconstruction, wherein the second stage of reconstruction is combined with final refinements to the ear construct and/or additional procedures to enhance facial contour and symmetry. METHODS: Retrospective analysis of patients who underwent two-stage microtia reconstruction by a single surgeon (NWB) was conducted in order to ascertain those that had ancillary procedures at the time of the second stage. Patient and operative details were collected. RESULTS: Thirty-four patients (male, 15, median age and age range at second stage, 11 and 10-18 years, respectively) who had complementary procedures executed during the second stage of auricular reconstruction were identified. Collectively, these included centralizing genioplasty (n = 1), fat transfer (n = 22), ear piercing (n = 7), and contralateral prominauris correction (n = 7). Six patients had correction for unilateral isolated microtia and in the remaining 28 patients, auricular reconstruction for microtia associated with a named syndrome. All patients reported a high rate of satisfaction with the result achieved and the majority (85%) reported no perceived need for additional surgical refinements to the ear or procedure(s) to achieve further facial symmetry. No peri- or post-operative complications were noted. CONCLUSION: Combining the final stage of autologous microtia reconstruction with other ancillary procedures affords a superior aesthetic outcome and decreased patient morbidity.

The role of transforming growth factor-beta, insulin-like growth factor I, and basic fibroblast growth factor in distraction osteogenesis of the mandible.

Distraction osteogenesis is a viable method for regenerating large amounts of bone. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. The basic biology of the process is still not well understood. The growth factor cascade is likely to play an important role in distraction. This study examines the growth factor cascade in a lengthened ovine mandible model. Twenty-four animals were divided into four groups with varying rates of distraction (1, 2, 3, and 4 mm/day). A unilateral distractor at the angle of the mandible was used. The mandibles were lengthened to 24 mm and fixed for a period of 5 weeks, after which the animals were killed. The sections were probed for transforming growth factor-beta, basic fibroblast growth factor, and insulin-like growth factor I. The growth factors studied were present in all four groups. Transforming growth factor-beta, basic fibroblast growth factor, and insulin-like growth factor I were present in both the bony matrix of the sections and the cytoplasm of the cells, osteoblasts, and a small number of mesenchymal cells. The sections obtained from groups distracted at faster rates showed stronger presence of the growth factors examined by more intense staining. In fracture healing, the localization of transforming growth factor-beta in stage I of healing corresponded with the precise region of intramembranous ossification in stage II. Diffuse presence of transforming growth factor-beta throughout the lengthened region corresponded with the process of intramembranous ossification observed in distraction. In fracture healing, insulin-like growth factor I and basic fibroblast growth factor have been shown to promote proliferation and differentiation of osteoblasts from precursor cells. The intense presence of insulin-like growth factor I and basic fibroblast growth factor in the distracted region may account for osteoblast proliferation and formation from precursor mesenchymal cells. Mechanical strain has been shown to increase the expression of transforming growth factor-beta and insulin-like growth factor I. Distraction may serve as a source of mechanical strain, which may explain, in part, the expression of these growth factors, particularly in the faster groups.