Guideline From the Brazilian Society of Surgical Oncology and Brazilian College of Surgeons in Preventing and Managing Acute Hypoparathyroidism After Thyroid Surgery.

The risk of hypoparathyroidism and hypocalcemia is a critical concern in thyroid surgery. Preserving parathyroid gland vascularization during surgery is essential for effective prevention. Preoperative and postoperative management, including calcium and Vitamin D supplementation, is paramount. Measurement of parathyroid hormone levels after surgery is the best predictor of hypoparathyroidism. This guideline offers recommendations for the prevention, diagnosis, and treatment of acute hypoparathyroidism and hypocalcemia after thyroid surgery.

Latin American Consensus on the Treatment of Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is well known as a serious health problem worldwide, especially in low-income countries or those with limited resources, such as most countries in Latin America. International guidelines cannot always be applied to a population from a large region with specific conditions. This study established a Latin American guideline for care of patients with head and neck cancer and presented evidence of HNSCC management considering availability and oncologic benefit. A panel composed of 41 head and neck cancer experts systematically worked according to a modified Delphi process on (1) document compilation of evidence-based answers to different questions contextualized by resource availability and oncologic benefit regarding Latin America (region of limited resources and/or without access to all necessary health care system infrastructure), (2) revision of the answers and the classification of levels of evidence and degrees of recommendations of all recommendations, (3) validation of the consensus through two rounds of online surveys, and (4) manuscript composition. The consensus consists of 12 sections: Head and neck cancer staging, Histopathologic evaluation of head and neck cancer, Head and neck surgery-oral cavity, Clinical oncology-oral cavity, Head and neck surgery-oropharynx, Clinical oncology-oropharynx, Head and neck surgery-larynx, Head and neck surgery-larynx/hypopharynx, Clinical oncology-larynx/hypopharynx, Clinical oncology-recurrent and metastatic head and neck cancer, Head and neck surgery-reconstruction and rehabilitation, and Radiation therapy. The present consensus established 48 recommendations on HNSCC patient care considering the availability of resources and focusing on oncologic benefit. These recommendations could also be used to formulate strategies in other regions like Latin America countries.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers.

Objective: The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas. Materials and methods: Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection? Results and conclusion: Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers

ABSTRACT Objective: The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas. Materials and methods: Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection? Results/conclusion: Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

Cancer risk-reducing surgery: Brazilian society of surgical oncology guideline part 1 (gynecology and breast).

BACKGROUND: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population. OBJECTIVES: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations. METHODS: The guideline was prepared from May to December 2021 by a multidisciplinary team of experts to discuss the surgical management of cancer predisposition syndromes. Fourteen questions were defined and assigned to expert groups that reviewed the literature and drafted preliminary recommendations. Following a review by the coordinators and a second review by all participants, the groups made final adjustments, classified the level of evidence, and voted on the recommendations. RESULTS: For all questions including risk-reduction bilateral salpingo-oophorectomy, hysterectomy, and mastectomy, major agreement was achieved by the participants, always using accessible alternatives. CONCLUSION: This and its accompanying article represent the first guideline in cancer risk reduction surgery developed by the BSSO, and it should serve as an important reference for the management of families with cancer predisposition.

Cancer risk-reducing surgery: Brazilian Society of Surgical Oncology Guideline Part 2 (Gastrointestinal and thyroid).

BACKGROUND: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population. OBJECTIVES: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations. METHODS: The guideline was prepared from May to December 2021 by a multidisciplinary team of experts to discuss the surgical management of cancer predisposition syndromes. Eleven questions were defined and assigned to expert groups that reviewed the literature and drafted preliminary recommendations. Following a review by the coordinators and a second review by all participants, the groups made final adjustments, classified the level of evidence, and voted on the recommendations. RESULTS: For all questions including risk-reducing colectomy, gastrectomy, and thyroidectomy, a major agreement was achieved by the participants, always using accessible alternatives. CONCLUSION: This and its accompanying article represent the first guideline in cancer risk reduction surgery developed by the BSSO and it should serve as an important reference for the management of families with cancer predisposition.

Sentinel lymph node biopsy for early squamous cell carcinoma of the lip and oral cavity: Real-world experience in Brazil.

BACKGROUND: This study aimed to evaluate the accuracy and oncological results of sentinel lymph node biopsy in patients with early lip and oral cavity squamous cell carcinoma (SCC) in a real-world scenario. METHODS: Retrospective study including seven Brazilian centers. RESULTS: Four-hundred and seven cN0 patients were accrued for 20 years. The rate of occult metastasis was 23.1% and 22 patients (5.4%) had regional failure. We found, for 5 years of follow-up, 85.3% of regional recurrence-free survival; 77.1% of disease-free survival; 73.7% of overall survival; and 86.7% of disease-specific survival. The rate of false-negative cases was 5.4%. CONCLUSION: In a real-world scenario, sentinel lymph node biopsy for patients with SCC of the lip and oral cavity proved feasible in different settings and to be oncologically safe, with similar rates of occult lymph node metastasis and false-negative cases, when compared to elective neck dissection, and with similar long-term survival to that reported historically.

Metastatic lymph node characteristics as predictors of recurrence/persistence in the neck and distant metastases in differentiated thyroid cancer

ABSTRACT Objective: The aim of this study was to evaluate the association between this characteristic and outcomes in patients with lymph node metastasis in a Brazilian cohort. Subjects and methods: This study examined a retrospective cohort of adult patients diagnosed with differentiated thyroid cancer and lymph node metastases from 1998 to 2015 in two referral centers. Number, location, size and extranodal extension (ENE) of metastatic lymph nodes were assessed and correlated with response to initial therapy. Results: A greater number of metastatic nodes, larger size, presence of lateral neck disease and ENE were all associated with a lower probability of achieving an excellent response to initial therapy (p ≤ 0.05 for all these parameters). Local recurrent disease had a significant association with lymph node number (6 in the recurrence/persistence group versus 4 in the non-recurrent group; p = 0.02) and ENE (19.2 versus 75%, p = 0.03). Lateral neck disease was the only characteristic associated with distant metastasis and was present in 52.1% of the group without metastasis and 70.4% of the group with metastasis (p = 0.001). Conclusion: The lymph node characteristics were associated with response to initial therapy and neck recurrence/persistence, confirming the importance of the analysis of these factors in risk stratification in a Brazilian population and its possible use to tailor initial staging and long term follow-up.

Somatostatin receptor subtype 1 might be a predictor of better response to therapy in medullary thyroid carcinoma.

PURPOSE: Medullary thyroid carcinoma (MTC) is a malignant neoplasm of parafollicular cells. Because it is a neuroendocrine tumor, it has known somatostatin receptors (SSTRs). The actual frequencies of the SSTR subtypes and their potential influences (by binding with endogenous somatostatin) on MTC cell proliferation have not been fully elucidated to date. The present study evaluated the occurrence of SSTR subtypes 1, 2, 3 and 5 as well as the possible role that each subtype plays in the clinical evolution of patients with MTC. METHODS: This retrospective, longitudinal study analyzed thyroid surgical material from 42 patients with MTC. Immunohistochemical staining was performed with monoclonal antibodies against subtypes 1, 2, 3 and 5 of SSTR. The histological material was classified as negative, focal positive or diffuse positive, in relation to each of the SSTR subtypes. The initial response to treatment, clinical course and patient mortality rate were assessed and related to the presence of SSTR subtypes. RESULTS: The most prevalent SSTR subtype was SSTR 3, which was found in 81% of the patients, when considering any pattern of positivity. However, subtype 2 had the lowest number of positive patients, with 28.6% demonstrating any positive pattern. Subtypes 1 and 5 had an intermediate prevalence of positivity, with subtype 1 present in 45.2% of the patients and subtype 5 positive in 54.8% of the patients, when considering any pattern of positivity. The presence of STR 1, in the form of diffuse positivity, independently predicted a better response to the initial therapy, with a hazard ratio (HR) of 4.80 (p = 0.03). CONCLUSION: This is the first study to show the correlation of the presence of SSTR1, detected by monoclonal immunohistochemical techniques, and better response to initial treatment and possibly better long-term clinical response in patients with MTC. In addition, these patients had low positivity rates for SSTR2, which might explain the low sensitivity of diagnostic and limited therapeutic response to octrotide based radioisotopes.

Nasal Cavity Paraganglioma: Literature Review and Discussion of a Rare Case.

Paragangliomas can be found from the skull base to the sacrum. Sinonasal paragangliomas are infrequent. A 16-year-old female reported spontaneous discrete bilateral epistaxis once a month beginning when she was 3 years of age. Computed tomography showed an expansive hypervascular mass occupying the right nasal cavity and nasopharynx. Sinonasal paragangliomas usually occur in middle-aged women. Radiologic investigation is essential for the diagnosis of sinonasal paragangliomas and evaluating extension of the lesion. Endoscopic and conventional approaches are effective, and preoperative embolization is paramount for reducing bleeding risk. Histopathological features cannot differentiate benign from malignant paragangliomas, and since metastasis may eventually occur, follow-up must be carried out for a long period of time.

Metastatic lymph node characteristics as predictors of recurrence/persistence in the neck and distant metastases in differentiated thyroid cancer.

OBJECTIVE: The aim of this study was to evaluate the association between this characteristic and outcomes in patients with lymph node metastasis in a Brazilian cohort. SUBJECTS AND METHODS: This study examined a retrospective cohort of adult patients diagnosed with differentiated thyroid cancer and lymph node metastases from 1998 to 2015 in two referral centers. Number, location, size and extranodal extension (ENE) of metastatic lymph nodes were assessed and correlated with response to initial therapy. RESULTS: A greater number of metastatic nodes, larger size, presence of lateral neck disease and ENE were all associated with a lower probability of achieving an excellent response to initial therapy (p ≤ 0.05 for all these parameters). Local recurrent disease had a significant association with lymph node number (6 in the recurrence/persistence group versus 4 in the non-recurrent group; p = 0.02) and ENE (19.2 versus 75%, p = 0.03). Lateral neck disease was the only characteristic associated with distant metastasis and was present in 52.1% of the group without metastasis and 70.4% of the group with metastasis (p = 0.001). CONCLUSION: The lymph node characteristics were associated with response to initial therapy and neck recurrence/persistence, confirming the importance of the analysis of these factors in risk stratification in a Brazilian population and its possible use to tailor initial staging and long term follow-up.

Prognostic Factors for Early and Long-Term Remission in Pediatric Differentiated Thyroid Carcinoma: The Role of Sex, Age, Clinical Presentation, and the Newly Proposed American Thyroid Association Risk Stratification System.

BACKGROUND: The incidence of pediatric differentiated thyroid carcinoma (DTC) has been rising in recent years, and the main risk factors for recurrence are lymph node and distant metastasis at diagnosis. Other clinical features remain unclear, such as the impact of age, sex, and puberty. Furthermore, until now, this population has been treated using the same strategies used to treat adults. In 2015, the American Thyroid Association (ATA) published the first guidelines targeted at this age group. The aims of this study were to investigate the prognostic factors for early and long-term remission and also to validate the ATA risk stratification proposal in a population outside the United States. METHODS: Clinical records from 118 patients <18 years old followed in two referral centers were reviewed. The median age was 12 years (range 4-18 years), and 20.3% (24 patients) were <10 years old at diagnosis. The median follow-up was 9.1 years. The majority were female (72%) and received total thyroidectomy and radioiodine therapy (RAI), and 61.8% were treated with more than one dose of RAI. The majority were classified as high risk (48.3%) by the new ATA pediatric guidelines due to distant metastasis (30 patients) or extensive lymph node involvement (27 patients). The remained were classified as low risk (31.3%) and intermediate risk (20.4%). RESULTS: Females with no lymph node or distant metastasis and low ATA pediatric risk were more likely to have no evidence of disease (p < 0.05) within the first year and also in the long term. In this study, age did not significantly predict outcomes. Furthermore, patients also benefitted from multiple doses of RAI, but when the cumulative activity was >400 mCi, this benefit was diminished. CONCLUSIONS: This study shows that the ATA risk stratification proposal for pediatric patients is useful in predicting early and long-term outcomes in pediatric patients with DTC. In addition, it shows that sex and metastatic disease are important prognostic factors in pediatric populations.

Proliferating trichilemmal tumor: case report / Tumor triquilemal proliferante: relato de caso

ABSTRACT The proliferating trichilemmal tumor is a lesion with trichilemmal differentiation, more common occurring among elderly women; it affects the scalp with sizes ranging from 2-10 cm. Microscopically, it is solid-cystic, well-defined, affecting the dermis and the subcutaneous cellular tissue. It presents trichilemmal and squamous keratinization. Pleomorphism may be present. Ghosts, apocrine and spindle cells can be observed. The differential diagnosis should be performed with malignant trichilemmal tumor and squamous cell carcinoma. Their behavior is benign and complete resection is recommended. Our goal is to report a case of proliferating trichilemmal tumor.

RESUMO O tumor triquilemal proliferante é uma lesão com diferenciação triquilemal, mais frequente em mulheres idosas; acomete o couro cabeludo, com tamanho variando de 2 cm a 10 cm. Microscopicamente, é sólido-cístico, bem delimitado, comprometendo a derme e o tecido celular subcutâneo. Apresenta ceratinização triquilemal e escamosa. Pleomorfismo pode estar presente. Células fantasmas, apócrinas e fusiformes podem ser observadas. O diagnóstico diferencial deve ser feito com o tumor triquilemal maligno e o carcinoma de células escamosas. O seu comportamento é benigno, sendo recomendada a ressecção completa. Nosso objetivo é relatar um caso de tumor triquilemal proliferante.

Predictors of postoperative complications, prolonged length of hospital stay, and short-term mortality in elderly patients with malignant head and neck neoplasm.

PURPOSE: To identify and assess predictors of short-term outcomes and a prolonged length of hospital stay after head and neck cancer surgery in older-old and oldest-old patients. PROCEDURES: Patients aged ≥75 years with head and neck cancer undergoing surgery at the Brazilian National Cancer Institute from January to December 2011 were assessed regarding postoperative complications, mortality, and length of hospital stay. RESULTS: Over the study period, 67 patients with head and neck cancer underwent surgery, 44.8% of whom developed complications within 30 days of surgery, surgical site and respiratory infections (29.9 and 20.9%, respectively) being the most common. The mean length of hospital stay was 7 days (range: 2-26). In multivariate analysis, previous radiotherapy, dependence in instrumental activities of daily living, and low serum hemoglobin (≤13.2 g/dl) were predictors of complications. In addition, the presence of at least 1 clinical or surgical complication, smoking, and an arm circumference ≤25 cm were independent predictors of a prolonged length of hospital stay. CONCLUSIONS: Complications after head and neck cancer surgery in the elderly are common and related to the prolonged length of hospital stay, both being influenced by previous radiotherapy, smoking, functional dependence in instrumental activities of daily living, and nutritional conditions. Such predictors should be considered in a preoperative assessment of elderly patients as these are modifiable risk factors.

Use of prototyping in preoperative planning for patients with head and neck tumors.

BACKGROUND: Prototyping technologies for reconstructions consist of obtaining a 3-dimensional model of the object of interest. Solid models are constructed by the deposition of materials in successive layers. The purpose of this study was to perform a double-blind, randomized, prospective study to evaluate the efficacy of prototype use in head and neck surgeries. METHODS: Thirty-seven cases were randomized into prototype and nonprototype groups. The following factors were recorded: the time of plate and locking screw apposition, flap size, time for reconstruction, and an aesthetic evaluation. RESULTS: The prototype group exhibited a reduced surgical time (43.7 minutes vs 127.7 minutes, respectively; p = .001), a tendency to reduce the size of the bone flap taken for reconstruction, and better aesthetic results than the group that was not prototyped. CONCLUSION: The use of prototyping demonstrated a trend toward a reduced surgical time, smaller bone flaps, and better aesthetic results.

Remoção de corpo estranho de vias aéreas de pacientes adultos traqueostomizados utilizando broncoscópio flexível: relato de dois casos / Removal of foreign body obstructing the airway in adult patients undergoing tracheostomy using flexible bronchoscope: two case report

Introdução: Aspiração de corpo estranho (CE) não é tão comumem adultos quanto em crianças. A presença de um estoma traquealpode ser um fator predisponente para a inalação de corpo estranhoem pacientes traqueostomizados. A história de broncoaspiraçãoassociada à radiografia simples de tórax pode fornecer subsídiossuficientes para identificação e diagnóstico da presença de CEna luz brônquica. A alternativa mais indicada para a remoçãode objetos das vias aéreas inferiores é a broncoscopia rígida,podendo ser associada ou não à broncoscopia flexível. Existempoucos relatos de remoção de corpo estranho em pacientestraqueostomizados. Objetivo: O presente artigo visa relatar aremoção de objetos da árvore traqueobrônquica de pacientestraqueostomizados, utilizando apenas o broncofibroscópio flexívele sua pinça de biópsia, assim como fazer uma revisão de literaturado assunto. Relato de caso: Dois pacientes matriculados naseção de cirurgia de cabeça e pescoço do Instituto Nacionalde Câncer, INCA/MS-RJ, traqueostomizados, submetidosa retirada de corpo estranho de vias aéreas inferiores combroncoscópio flexível com resultado satisfatório. Comentáriosfinais: Corpos estranhos aspirados para via aérea podemser removidos com sucesso através de broncoscopia flexível.

Retalho de Martin modificado / Modified Martin flap

O retalho submentoniano é versátil e útil em reconstruções dedefeitos intra-orais, trato aero- digestivo e 1/3 inferior da face.Relato de caso: Apresentamos o retalho de Martin modificadopara defeito extenso de mucosa jugal á esquerda até palato,associado a retalho Karapandizix e nasogeniano para terço dolábio superior esquerdo e dois terços do lábio inferior. O retalhode Martin modificado é uma variação segura, útil, com bom arcode rotação, cor e textura similar a da face.

Valor prognóstico da espessura tumoral no carcinoma escamocelular avançado do lábio inferior e sua correlação com metástases cervicais / Prognostic value of tumor thickness in advanced squamous cell carcinoma of the lower lip and their correlation with neck metastases

Introdução: O carcinoma escamocelular (CEC) do lábio inferioré um dos tumores malignos mais comuns da cavidade oral. Aespessura tumoral é relativamente um novo fator prognósticopara o câncer de lábio inferior e sua importância em casosavançados é incerto. Objetivo: Avaliar o valor prognóstico daespessura tumoral no CEC avançado do lábio inferior. Método:Análise retrospectiva de 31 pacientes diagnosticados com CECavançado do lábio inferior e tratados cirurgicamente no InstitutoNacional do Câncer (Rio de Janeiro, Brasil), durante o períodoentre 2000 e 2009. Foram analisadas variáveis relacionadasà espessura tumoral, metástase cervical e sobrevida global.Resultados: Metástases cervicais ocorreram em 61,2% dospacientes. A espessura tumoral foi um fator preditor independentede metástases cervicais, e quando utilizado o ponto de corte de 5mm, a taxa de metástases cervicais foi de 5,3% em comparaçãocom 94,7% dos pacientes com tumores maiores que 5 mm deespessura (p = 0,001). A ocorrência de metástases cervicais foium fator preditor independente para a redução da sobrevivênciaglobal (p = 0,003). Conclusão: A espessura tumoral foi um fatorpreditor independente de metástase cervical no CEC avançadode lábio inferior. Na ocorrência de metástases cervicais há umasignificativa redução da sobrevida global.

Surgical management of parapharyngeal ganglioneuroma: case report and review of the literature.

Parapharyngeal ganglioneuroma is a rare benign tumor, with fewer than 40 cases having been reported in the literature. We report a case of parapharyngeal ganglioneuroma in a child, including the presentation, diagnostic testing, treatment, outcome and a review of the literature. The patient presented with a large cervical mass arising from the cervical sympathetic chain. Complete excision of the ganglioneuroma was possible via a transcervical dissection approach without mandibulotomy. Clinical follow-up was conducted, and no recurrence has been observed to date.

Uso da prototipagem no planejamento pré-operatório de pacientes com tumores de cabeça e pescoço / [Use of prototyping in the preoperative planning of patients with head and neck tumors]

Introdução: Prototipagem é definida como a fabricação de modelos físicos da anatomia humana, dimensionalmente precisos, através de dados das imagens médicas obtidas por tomografia computadorizada, utilizando tecnologias de prototipagem rápida. Consiste em se obter um modelo tridimensional dos objetos de interesse. Os modelos sólidos são construídos pela deposição de camadas sucessivas de materiais. Objetivo: Demonstrar resultados de um ensaio clínico piloto, prospectivo, randomizado, duplo cego, com objetivo de avaliar a eficácia do uso da prototipagem no planejamento pré e trans-operatório dos tumores da cabeça e pescoço. Materiais e Métodos: São apresentados os 37 casos do estudo. O primeiro grupo (grupo A) randomizado submetido à mandibulectomia com reconstrução microcirúrgica tendo a prototipagem como auxílio, e o segundo grupo (grupo B) com o mesmo tipo de tumor, submetido à mesma técnica cirúrgica, porém, sem prototipagem. São avaliados: redução no tempo de aposição de placa e de parafusos, redução no tamanho do retalho utilizado, melhor escolha de parafusos, melhor conhecimento tridimensional do tumor, redução de custos cirúrgicos e anestésicos assim como avaliação da estética. Os protótipos foram confeccionados no CenPRA (Centro de Pesquisa Renato Archer – Ministério de Ciência e Tecnologia – Campinas/ SP). Resultados: O grupo A apresentou tempo médio reduzido, com retirada da mandíbula e retirada do retalho em menor tempo (43.7 minutos vs. 127.7 minutos, respectivamente; p = 0.001), sem excessos de osso desperdiçado (2.1 cm vs. 8.7 cm, respectivamente) e moldagem de placas com colocação de parafusos em menor tempo (30.4 minutos vs. 86.6 minutos, respectivamente; p = 0.001) quando comparado com grupo B. Com esta diminuição no tempo cirúrgico, houve redução na utilização de anestésicos e de custos envolvidos e melhores resultados estéticos foram alcançados no grupo da prototipagem...

Background: Prototyping is defined as the fabrication of physical models of human anatomy, obtained from medical data (computadorized tomography). Reconstruction is obtained in order to achieve a tridimensional model of the desired objects. Solid models are built through the sedimentation of successive layers of the utilized material. Objective: To demonstrate the results of a prospective, randomized, doble-blinded study seeking the evaluation of the efficacy of prototyping in medical planning, before and after operative techniques are applied, in head and neck tumor disorders. Material and methods: 37 cases compose this study. The first randomized group (A group) was submitted to microsurgical reconstruction with prototyping after mandibulectomy had been performed. The second randomized group (B group), presenting the same tumor features, was submitted to the same kind of surgery in function of the tumor presentation, in exception to the use of the prototyping. A few variables were evaluated: time of the plate and screws exposure, flap size, screw choice, knowledge of tumor tridimensionally and reduction of costs and anesthetics as well as the final aesthetic result. Prototypes were manufactured at CenPRA (Centro de Pesquisa Renato Archer – Ministério de Ciência e Tecnologia – Campinas/ SP). Results: The A Group presented reduced surgical median time, taking into consideration mandibulectomy and bone flap harvesting (43.7 minutes vs. 127.7 minutes, respectively; p = 0.001), smaller flap size (2.1 cm vs. 8.7 cm, respectively) and diminished time with plate modeling and screw adjustments (30.4 minutes vs. 86.6 minutes, respectively; p = 0.001), taking account the B group. With surgical time reduction, we had a reduction of anesthetics and costs. The aesthetic results were better in the prototyped group...