Dosimetric Impact of Titanium Alloy Implant in Spinal IMRT Plan / 中国医疗器械杂志

The purpose of this study is to establish and apply a correction method for titanium alloy implant in spinal IMRT plan, a corrected CT-density table was revised from normal CT-density table to include the density of titanium alloy implant. Dose distribution after and before correction were calculated and compared to evaluate the dose deviation. Plans were also copied to a spinal cancer simulation phantom. A titanium alloy fixation system for spine was implanted in this phantom. Plans were recalculated and compared with the measurement result. The result of this study shows that the max dose of spinal cord showed significant difference after correction, and the deviation between calculation results and measurement results was reduced after correction. The method for expanding the range CT-density table, which means that the density of titanium alloy was included, can reduce the error in calculation.

Analysis of Imaging Performance Standards of CBCT X-IGRT System Used in Radiotherapy / 中国医疗器械杂志

This article briefly describes the imaging performance standards of the kilovolt X-ray image guidance system used in radiotherapy, analyzes the main aspects that should be considered in the image quality of X-IGRT system, and focuses on parameters that should be considered in the imaging performance evaluation criteria of the CBCT X-IGRT. The purpose is to sort out the imaging performance evaluation standards of kilovolt X-IGRT system, clarify the image quality requirements of X-IGRT equipment, and reach a consensus when evaluating the imaging performance of X-IGRT system.

Analysis of risk factors of radiation-induced toxicity in limited-stage small cell lung cancer treated with hypofractionated intensity-modulated radiotherapy / 中华肿瘤杂志

Objective: To compare the incidence of radiation-related toxicities between conventional and hypofractionated intensity-modulated radiation therapy (IMRT) for limited-stage small cell lung cancer (SCLC), and to explore the risk factors of hypofractionated radiotherapy-induced toxicities. Methods: Data were retrospectively collected from consecutive limited-stage SCLC patients treated with definitive concurrent chemoradiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from March 2016 to April 2022. The enrolled patients were divided into two groups according to radiation fractionated regimens. Common Terminology Criteria for Adverse Events (CTCAE, version 5.0) was used to evaluate the grade of radiation esophagus injuries and lung injuries. Logistic regression analyses were used to identify factors associated with radiation-related toxicities in the hypofractionated radiotherapy group. Results: Among 211 enrolled patients, 108 cases underwent conventional IMRT and 103 patients received hypofractionated IMRT. The cumulative incidences of acute esophagitis grade ≥2 [38.9% (42/108) vs 35.0% (36/103), P=0.895] and grade ≥ 3 [1.9% (2/108) vs 5.8% (6/103), P=0.132] were similar between conventional and hypofractionated IMRT group. Late esophagus injuries grade ≥2 occurred in one patient in either group. No differences in the cumulative incidence of acute pneumonitis grade ≥2[12.0% (13/108) vs 5.8% (6/103), P=0.172] and late lung injuries grade ≥2[5.6% (6/108) vs 10.7% (11/103), P=0.277] were observed. There was no grade ≥3 lung injuries occurred in either group. Using multiple regression analysis, mean esophageal dose ≥13 Gy (OR=3.33, 95% CI: 1.23-9.01, P=0.018) and the overlapping volume between planning target volume (PTV) and esophageal ≥8 cm(3)(OR=3.99, 95% CI: 1.24-12.79, P=0.020) were identified as the independent risk factors associated with acute esophagitis grade ≥2 in the hypofractionated radiotherapy group. Acute pneumonitis grade ≥2 was correlated with presence of chronic obstructive pulmonary disease (COPD, P=0.025). Late lung injuries grade ≥2 was correlated with tumor location(P=0.036). Conclusions: Hypofractionated IMRT are tolerated with manageable toxicities for limited-stage SCLC patients treated with IMRT. Mean esophageal dose and the overlapping volume between PTV and esophageal are independently predictive factors of acute esophagitis grade ≥2, and COPD and tumor location are valuable factors of lung injuries for limited-stage SCLC patients receiving hyofractionated radiotherapy. Prospective studies are needed to confirm these results.

Feasibility Study of Beam Angle Optimization Based on Scripts in Automated-planning for Liver Cancer / 中国医疗器械杂志

OBJECTIVE@#To study the feasibility and potential benefits of beam angle optimization (BAO) to automated planning in liver cancer.@*METHODS@#An approach of beam angle sampling is proposed to implement BAO along with the module Auto-planning in treatment planning system (TPS) Pinnacle. An in-house developed plan quality metric (PQM) is taken as the preferred evaluating method during the sampling. The process is driven automatically by in-house made Pinnacle scripts both in sampling and scoring. In addition, dosimetry analysis and physician's opinion are also performed as the supplementary and compared with the result of PQM.@*RESULTS@#It is revealed by the numerical analysis of PQM scores that only 15% patients whose superior trials evaluated by PQM are also the initial trials. Gantry optimization can bring benefit to plan quality along with auto-planning in liver cancer. Similar results are provided by both dose comparison and physician's opinion.@*CONCLUSIONS@#It is possible to introduce a full automated approach of beam angle optimization to automated planning process. The advantages of this procedure can be observed both in numerical analysis and physician's opinion.

Progress in Development of Dose Verification System Software KylinRay-Dose4D / 中国医疗器械杂志

Advanced radiotherapy technology enables the dose to more accurately conform to the tumor target area of the patient, providing accurate treatment for the patient, but the gradient of the patient's radiation dose at the tumor edge is getting larger, which putting forward higher requirements for radiotherapy dose verification. The dose verification system software KylinRay-Dose4D can verify the patient's pre-treatment plan and the in vivo/on-line dose during the patient's treatment, providing important reference for the physicist to modify the radiotherapy plan and ensuring that the patient receives accurate treatment. This study introduces the overall design and key technologies of KylinRay-Dose4D, and tests the pre-treatment plan dose checking calculation and 2D/3D dose verification through clinical cases. The test results showed that the 2D/3D gamma pass rate (3 mm/3%) of KylinRay-Dose4D reconstructed dose compared with TPS plan dose and measured dose is larger than 95%, which indicating that the reconstructed dose of KylinRay-Dose4D meets the requirement of clinical application.

Leak and Scattering Assessment by Optically Stimulated Luminescence Dosimetry in a Helical Linear Accelerator / Valoración de Fuga y Dispersión por medio de Dosimetría de Luminiscencia Estimulada Ópticamente (OSL) en un Acelerador Lineal Helicoidal

Radiation absorbed doses to organs outside the radiation therapy treatment beam can be significant and therefore of clinical interest. Two sets of out-of-beam measurements were performed measuring the leak dose and the scattered dose, at 5 points within the accelerator components (accelerator tube and collimator) and at 21 points on the equipment and surroundings based on a positioning scheme. For this purpose, 52 Optically Stimulated Luminescence (OSL) dosimeters were used in a latest generation helical linear accelerator. Of the 200 cGy fired at a cheese-like phantom, 0.332% of the out-of-beam dose contribution was found to come from the leak and 0.784% was transformed into scattering. For these dose values, estimates of the risk of second tumors in long-term survivors indicate a reduced probability of acquiring a second secondary radiation malignancy, based on information from the 1990 BEIR Committee report.

La dosis absorbida de radiación a órganos fuera del haz de tratamiento de radioterapia puede ser significativa y, por lo tanto, de interés clínico. Se realizaron dos sets de mediciones fuera del haz para determinar la dosis de fuga y la dosis dispersa, en 5 puntos dentro de los componentes del acelerador (tubo de aceleración y colimador) y 21 puntos en el equipo y alrededores basado en un esquema de posicionamiento. Para este fin se utilizaron 52 dosímetros de luminiscencia estimulada ópticamente (OSL, Optically Stimulated Luminescence), en un acelerador lineal helicoidal de última generación. De los 200 cGy disparados a un maniquí tipo queso, se encontró que el 0.332% de la contribución de dosis fuera del haz provenía de la fuga y 0.784% se transforma en dispersión. Para estos valores de dosis, las estimaciones del riesgo de segundos tumores en los supervivientes a largo plazo indican una reducida probabilidad de contraer una segunda malignidad por radiación secundaria, según la información del informe del Comité BEIR de 1990.

Impact of multi-leaf collimator positioning accuracy on quality control of volumetric modulation arc therapy plan for cervical cancer treated with Elekta linear accelerator / 南方医科大学学报

OBJECTIVE@#To investigate the influence of positioning accuracy of the multi-leaf collimators (MLC) on the passing rate of the plan dose verification for volumetric modulation arc therapy (VMAT) of cervical cancer using an Elekta linear accelerator.@*METHODS@#The dose distributions were measured using Sun Nuclear's Mapcheck and Arccheck semiconductors matrix before and after MLC calibration in30 cervical cancer patients undergoing VMAT. Dosimetric comparisons were performed with 2D and 3D gamma passing rates of 3%, 3 mm and 2%, and 2 mm. The 3D gamma distribution was reconstructed with respect to the patient's anatomy using 3DVH software to evaluate the possible influence of MLC positioning accuracy.@*RESULTS@#Before and after MLC calibration, the gamma passing rates of Mapcheck were (88.80±1.81)% and (99.25 ± 0.53)% under 3% and 3 mm standard, respectively, with an average increase of 10.45%. The corresponding gamma passing rates of Arccheck were (87.61±1.98)% and (98.13±0.99)%, respectively, with an average increase of 10.52%. The gamma passing rates of 3DVH were (89.87±2.28)% and (98.3±1.15)%, respectively, with an average increase of 8.43%.@*CONCLUSION@#The MLC positioning accuracy is one of the main factors influencing dosimetric accuracy of VMAT for cervical cancer. The application of Autocal software facilitates MLC calibration and improves the accuracy and safety of VMAT delivery for cervical cancer.

Intensity modulated radiotherapy (IMRT) or conformational radiotherapy (3D-CRT) with conventional fractionation for prostate cancer: Is there any clinical difference?

ABSTRACT Purpose: To compare the treatment outcomes of a cohort of prostate cancer patients treated with conventional schedule using IMRT or 3DRT technique. Materials and Methods: Between 2010-2017, 485 men with localized prostate cancer were treated with conventional radiotherapy schedule with a total dose ≥74Gy using IMRT (231) or 3DCRT (254). Late gastrointestinal (GI) and genitourinary (GU) toxicity were retrospectively evaluated according to modified RTOG criteria. The biochemical control was defined by the Phoenix criteria (nadir + 2ng/mL). The comparison between the groups included biochemical recurrence free survival (bRFS), overall survival (OS) and late toxicity. Results: With a median follow-up of 51 months (IMRT=49 and 3DRT=51 months), the maximal late GU for >=grade- 2 during the entire period of follow-up was 13.1% in the IMRT and 15.4% in the 3DRT (p=0.85). The maximal late GI ≥ grade- 2 in the IMRT was 10% and in the 3DRT 24% (p=0.0001). The 5-year bRFS for all risk groups with IMRT and 3D-CRT was 87.5% vs. 87.2% (p=0.415). Considering the risk-groups no significant difference for low-, intermediate- and high-risk groups between IMRT (low-95.3%, intermediate-86.2% and high-73%) and 3D-CRT (low-96.4%, intermediate-88.2% and high-76.6%, p=0.448) was observed. No significant differences for OS and DMFS were observed comparing treatment groups. Conclusion: IMRT reduces significantly the risk of late GI severe complication compared with 3D-CRT using conventional fractionation with a total dose ≥74Gy without any differences for bRFS and OS.

Cosmesis in patients with breast neoplasia submitted to the hypofractionated radiotherapy with of intensity-modulated beam

SUMMARY OBJECTIVE: To assess the cosmetic satisfaction of patients diagnosed with breast cancer submitted to the hypofractionated radiotherapy with IMRT (hIMRT) technique and its correlation with dosimetric data of the radiotherapy planning. MATERIALS AND METHODS: The retrospective cohort study that assessed women with a diagnosis of malignant breast neoplasia submitted to the conservative treatment or radical mastectomy and treated with hIMRT. In the period between August 2007 to December 2014, in a philanthropic / private institution, 170 records were selected. The cosmetic assessment was carried out by means of the Harvard/RTOG/NSABP scale with one-year minimum range after treatment. The collected dosimetric data were: breast / chest wall volume, volume that received 95% (V95%) and 107% (V107%) of the prescribed dose. RESULTS: The volume of the treated breasts ranged from 169 to 2.103 ml (median = 702; IQR: 535 to 914 ml). Median V95% was 86.7% (54.6-96.6%; IQR: 80.0% to 90.6%); eight (5.7%) patients had V95% higher than 95%. Median V107% was 0% (0%-16.3%; IQR: 0.0% to 0.3% and 13); 9.3% patients had V107% higher than 2%. One hundred and thirty-three (78.2%) patients responded to the cosmetic assessment: 99 (74.4%) considered the cosmetic results excellent. Significant associations between cosmetic assessment and breast volume (p=0.875), V95% (p=0.294) e V107% (p=0.301) were not found. CONCLUSION: The cosmetic results showed favorable when using hIMRT, and the lack of correlation with usual the dosimetric data illustrates the capacity of hIMRT to minimize the heterogeneity of the dose in this endpoint, even in voluminous breasts.

RESUMO OBJETIVO: Avaliar a satisfação cosmética de pacientes diagnosticadas com câncer de mama submetidas à radioterapia hipofracionada com técnica IMRT (hIMRT) e sua correlação com dados dosimétricos do planejamento radioterápico. MATERIAIS E MÉTODOS: Estudo de coorte retrospectivo que avaliou mulheres com diagnóstico de neoplasia maligna de mama submetidas a tratamento conservador ou mastectomia radical e tratadas com hIMRT. No período de agosto de 2007 a dezembro de 2014, em uma instituição filantrópica/particular, foram selecionados 170 prontuários. A avaliação cosmética foi feita por meio da escala de Harvard/RTOG/NSABP com um intervalo mínimo de um ano após o tratamento. Dados dosimétricos coletados foram: volume da mama/plastrão, volume que recebeu 95% (V95%) e 107% (V107%) da dose prescrita. RESULTADOS: O volume das mamas tratadas variou de 169 a 2.103 ml (mediana = 702; IQR: 535 a 914 ml). O V95% mediano foi 86,7% (54,6-96,6%; IQR: 80,0% a 90,6%); oito (5,7%) pacientes tiveram o V95% superior a 95%. O V107% mediano foi 0% (0%-16,3%; IQR: 0,0% a 0,3% e 13); 9,3% pacientes tiveram o V107% superior a 2%. Cento e trinta e três (78,2%) pacientes responderam à avaliação cosmética: 99 (74,4%) consideraram o resultado cosmético excelente. Não foram encontradas associações significativas entre a avaliação cosmética e o volume da mama (p=0,875), V95% (p=0,294) e V107% (p=0,301). CONCLUSÕES: Os resultados cosméticos mostraram-se favoráveis com o uso de hIMRT, e a ausência de correlação com os dados dosimétricos usuais ilustra a capacidade do hIMRT em minimizar a heterogeneidade da dose neste desfecho, mesmo em mamas volumosas.

Intensity-modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3D-CRT) for head and neck cancer: cost-effectiveness analysis

SUMMARY BACKGROUND: A cost-effectiveness analysis of IMRT compared to 3D-CRT for head and neck cancer patients (HNCPs) was conducted in the Brazilian Public Health System. METHODS: A Markov model was used to simulate radiation therapy-induced dysphagia and xerostomia in HNCPs. Data from the PARSPORT trial and the quality-of-life study were used as parameters. The incremental cost-effectiveness ratio (ICER) and cost per quality-adjusted life-year (QALY) gained were calculated. RESULTS: At 2 years, IMRT was associated with an incremental benefit of 0.16 QALYs gained per person, resulting in an ICER of BRL 31,579 per QALY gained. IMRT was considered cost-effective when using the guideline proposed by the World Health Organization (WHO) of three times the national gross domestic product (GDP) per capita (BRL 72,195). Regarding life expectancy (15 years), the incremental benefit of IMRT was 1.16 QALYs gained per person, with an ICER of BRL 4,341. IMRT was also cost-effective using the WHO definition, which states that the maximum cost is equal to the GDP per capita (BRL 24,065). CONCLUSIONS: IMRT was considered cost-effective from the perspective of the Brazilian public health system.

RESUMO INTRODUÇÃO: Foi realizada uma análise de custo-efetividade da radioterapia com intensidade modulada de feixe (IMRT) comparada com a radioterapia conformada para pacientes com câncer de cabeça e pescoço (CCP) no contexto do Sistema Único de Saúde (SUS). MÉTODOS: Foi elaborado um modelo de Markov para comparar os custos médicos diretos e os desfechos de saúde relacionados à qualidade de vida do paciente pós-intervenção radioterápica sofrendo de xerostomia e disfagia. Com essa finalidade, foram usados os dados do estudo PARSPORT e parâmetros de qualidade de vida. Os resultados comparativos das estratégias alternativas de tratamento foram medidos pela razão de custo-efetividade incremental (RCEI). O desfecho analisado foi o de anos de vida ajustados à qualidade (QALY). RESULTADOS: Em um horizonte de tempo de dois anos, a IMRT foi associada com um benefício incremental de ganho de 0,16 QALYs por indivíduo, resultando em um RCEI de R$ 31.579 por QALY ganhado. A IMRT foi custo-efetivo, adotando-se o limite máximo de disposição a pagar, proposto pela OMS, de três vezes o PIB per capita nacional, equivalente a R$ 72.195. No horizonte de tempo de 15 anos, o benefício incremental de ganho foi de 1,16 QALYs por indivíduo, com um RCEI de R$ 4.341. A IMRT foi custo-efetivo, adotando-se o limite de disposição a pagar, proposto pela OMS, de uma vez o PIB per capita nacional, equivalente a R$ 24.065. CONCLUSÃO: A IMRT foi considerada um tratamento custo-efetivo na perspectiva do SUS.

Radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado / Intensity modulated radiation therapy (IMRT) for the treatment of early and locally advanced head and neck tumors

CONTEXTO: O tumor de cabeça e pescoço é um grupo heterogêneo de doenças incluindo tumores com diversos tipos histológicos, de cavidade oral, faringe, laringe, narinas, seios paranasais, tireoide, glândulas salivares. A radioterapia tem como importante efeito adverso a lesão de estruturas nobres como glândulas submandibulares e parótidas. TECNOLOGIA: Radioterapia por Intensidade Modulada (IMRT). INDICAÇÃO: Tumores de Cabeça e Pescoço. PERGUNTA: A técnica de radioterapia por IMRT é mais eficaz e segura do que as modalidades de radioterapia convencional (2D) ou tridimensional (3D)? EVIDÊNCIAS CIENTÍFICAS: os estudos apresentam baixa qualidade, demonstrando superioridade apenas em relação a xerostomia observada pelo médico. Existe dúvida em relação ao risco de neoplasias secundárias, com provável aumento do risco. A implementação apresenta dificuldades como adaptação do ambiente, treinamento da equipe e maior duração de cada seção. AVALIAÇÃO ECONÔMICA: elevado valor estimado de RCEI R$ 574.087,00/QALY. AVALIAÇÃO DE IMPACTO ORÇAMENTÁRIO: anual R$ 67.152.510,00 e em 5 anos R$ 335.762.550,00. DISCUSSÃO: As vantagens são incertas, o procedimento é mais longo e existe risco de incremento em neoplasias secundárias, sem impacto favorável em sobrevida. RECOMENDAÇÃO DA CONITEC: A matéria será disponibilizada em Consulta Pública com recomendação preliminar não favorável. CONSULTA PÚBLICA: Ao considerar os riscos e benefícios potenciais da tecnologia, a matéria foi disponibilizada em Consulta Pública com recomendação da Conitec não favorável. Após a análise das 138 contribuições recebidas na Consulta Pública, a Conitec deliberou por recomendar a não incorporação da radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado. DELIBERAÇÃO FINAL: Os membros presentes deliberaram por unanimidade recomendar a não incorporação de um procedimento específico para radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado. Foi assinado o Registro de Deliberação n˚174/2015. A recomendação será encaminhada para decisão do Secretário da SCTIE. O representante do CFM se absteve de votar por alegar conflito de interesse com o tema. DECISÃO: Não incorporar de procedimento específico para radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado, no âmbito do Sistema Único de Saúde ­ SUS, dada pela Portaria SCTIE-MS nº 7 publicada no Diário Oficial da União (D.O.U.) nº 18, de 27 de janeiro de 2016, pág. 57.(AU)

Tratamiento no quirúrgico en cáncer epidermoide de orofaringe avanzado: análisis de resultados oncológicos en función del subsitio tumoral y fraccionamiento de radioterapia / Nonsurgical treatment in advanced oropharyngeal squamous cell cancer

Objetivo: Reportar resultados de nuestro protocolo de radioquimioterapia concomitante exclusiva en el cáncer de orofaringe avanzado. Materiales y métodos: Estudio retrospectivo que incluyó 87 pacientes. Se realizó radioterapia concomitante con cisplatino semanal. Se aceptó la realización de fraccionamiento convencional (FC), hiperfraccionamiento (Hfx) o fraccionamiento acelerado tipo boost concomitante (FABC). Se revisó la sobrevida global (SG), sobrevida libre de enfermedad (SLE), sobrevida libre de recidiva local (SLRL) y regional (SLRR) según subsitio y fraccionamiento. Resultados: Ingresaron 87 pacientes. Mediana de seguimiento: 120 meses. El 53, 30 y 17% recibieron FC, FABC y Hfx respectivamente. La SG a 2, 5 y 10 años fue de un 73, 61 y 43% respectivamente. La SG a 5 años según subsitio anatómico fue: amígdala 74%, paladar blando 33%, base de lengua 33%, y pared faríngea posterior 33%. Al comparar la SG de amígdala versus otros subsitios se alcanza una diferencia estadísticamente significativa (p < 0,001). La mediana de SG para amígdala no fue alcanzada, mientras que en otros subsitios fue de 22 meses. La SLE fue diferente en los distintos subsitios, superior en amígdala y diferente entre los distintos fraccionamientos, a favor de Hfx, alcanzando diferencias significativas. Las mismas tendencias se demostraron en SLRL y SLRR. Observamos un 23% de segundos primarios, siendo el pulmón el sitio más frecuente. Conclusión: La radioterapia concomitante con cisplatino semanal es un tratamiento adecuado para el cáncer de orofaringe. Ofrece excelentes resultados en cáncer de amígdala, especialmente con fraccionamiento modificado. Para los otros subsitios nos parece recomendable explorar nuevas estrategias de tratamiento.

Objective: To report results of our concomitant radiochemotherapy protocol for advanced oropharyngeal cancer. Materials and methods: Retrospective study. Concomitant radiochemotherapy was performed with weekly cisplatin. Conventional fractionation (CF), hyperfractionation (Hfx) or accelerated fractionation with concomitant boost (FABC) were accepted. Overall survival (OS), Disease-free survival (RFS), Local relapse-free survival (LRFS) and Regional relapse-free survival (RRFS) were calculated, according subsite and radiotherapy fractionation. Results: We found 87 patients. Median follow-up: 120 months. 53%, 30% and 17% received FC, FABC, Hfx respectively. OS at 2, 5 and 10 years was 73%, 61% and 43% respectively. The 5-year OS was, by anatomic subsite: Tonsillar 74%, 33% soft palate, base of tongue 33%, and 33% for posterior pharyngeal wall. By comparing the OS in tonsil versus other subsites we found statistically significant difference in favor of tonsillar cancer (P < .001). Median OS for tonsillar cancer was not achieved, while in other subsites was 22 months. DFS was different in different subsites, better for amygdala and different among different fractionations, better for Hfx, reaching significant differences. The same trends were demonstrated in LRFS and RRFS. We observed a 23% of second cancers, being lung the most common site. Conclusion: Concomitant radiotherapy with weekly cisplatin is an appropriate treatment for oropharyngeal cancer. It provides excellent outcomes in tonsillar cancer, especially with modified fractionation and Hfx type. For other subsites it seems advisable to explore a new treatment approach.

Spine radiosurgery for the local treatment of spine metastases: Intensity-modulated radiotherapy, image guidance, clinical aspects and future directions

Many cancer patients will develop spinal metastases. Local control is important for preventing neurologic compromise and to relieve pain. Stereotactic body radiotherapy or spinal radiosurgery is a new radiation therapy technique for spinal metastasis that can deliver a high dose of radiation to a tumor while minimizing the radiation delivered to healthy, neighboring tissues. This treatment is based on intensity-modulated radiotherapy, image guidance and rigid immobilization. Spinal radiosurgery is an increasingly utilized treatment method that improves local control and pain relief after delivering ablative doses of radiation. Here, we present a review highlighting the use of spinal radiosurgery for the treatment of metastatic tumors of the spine. The data used in the review were collected from both published studies and ongoing trials. We found that spinal radiosurgery is safe and provides excellent tumor control (up to 94% local control) and pain relief (up to 96%), independent of histology. Extensive data regarding clinical outcomes are available; however, this information has primarily been generated from retrospective and nonrandomized prospective series. Currently, two randomized trials are enrolling patients to study clinical applications of fractionation schedules spinal Radiosurgery. Additionally, a phase I clinical trial is being conducted to assess the safety of concurrent stereotactic body radiotherapy and ipilimumab for spinal metastases. Clinical trials to refine clinical indications and dose fractionation are ongoing. The concomitant use of targeted agents may produce better outcomes in the future.

Radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado / Intensity modulated radiation therapy (IMRT) for the treatment of early and locally advanced head and neck tumors

Contexto: O tumor de cabeça e pescoço é um grupo heterogêneo de doenças incluindo tumores com diversos tipos histológicos, de cavidade oral, faringe, laringe, narinas, seios paranasais, tireoide, glândulas salivares. A radioterapia tem como importante efeito adverso a lesão de estruturas nobres como glândulas submandibulares e parótidas. Pergunta: A técnica de radioterapia por IMRT é mais eficaz e segura do que as modalidades de radioterapia convencional (2D) ou tridimensional (3D)? Evidências científicas: os estudos apresentam baixa qualidade, demonstrando superioridade apenas em relação a xerostomia observada pelo médico. Existe dúvida em relação ao risco de neoplasias secundárias, com provável aumento do risco. A implementação apresenta dificuldades como adaptação do ambiente, treinamento da equipe e maior duração de cada seção. Discussão: As vantagens são incertas, o procedimento é mais longo e existe risco de incremento em neoplasias secundárias, sem impacto favorável em sobrevida. Decisão: Não incorporar de procedimento específico para radioterapia de intensidade modulada (IMRT) para o tratamento de tumores de cabeça e pescoço em estágio inicial e localmente avançado, no âmbito do Sistema Único de Saúde ­ SUS, dada pela Portaria SCTIE-MS nº 7 publicada no Diário Oficial da União (D.O.U.) nº 18, de 27 de janeiro de 2016.

Alternative treatment for open bite Class III malocclusion in a child with Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is a rare genetic condition that affects approximately 1 in every 20,000 - 50,000 live births. WBS children have specific skeletal deformities, dental malformations and rare lingual muscle dysfunction. The need for orthodontic and orthognathic therapy has arisen and has been considered a real clinical challenge even for experienced professionals, once it requires a complex and individualized treatment plan. This study reports a case of orthopedic expansion of the maxilla, in which a modified facial mask was used for protraction of the maxillary complex associated with clockwise rotation of the maxilla. In addition, special considerations about treatment time and orthopedic outcomes are discussed.

A síndrome de Williams-Beuren (WBS) é uma doença genética rara, acometendo, aproximadamente, de 1:20.000 a 1:50.000 crianças nascidas. As crianças com WBS têm deformidades esqueléticas específicas, má formações dentárias e, algumas vezes, disfunção muscular da língua. As necessidades ortodônticas e ortognáticas têm sido consideradas um verdadeiro desafio clínico, até mesmo para aqueles profissionais com vasta experiência, uma vez que requerem um plano de tratamento individualizado e complexo. Esse relato de caso aborda uma expansão ortopédica da maxila, em que foi utilizada uma máscara facial modificada para protração do complexo maxilar, acompanhada de uma rotação horária da maxila. Além disso, considerações especiais sobre o tempo de tratamento e resultados ortopédicos são discutidas.

Dosimetric Effects of Magnetic Resonance Imaging-assisted Radiotherapy Planning: Dose Optimization for Target Volumes at High Risk and Analytic Radiobiological Dose Evaluation

Based on the assumption that apparent diffusion coefficients (ADCs) define high-risk clinical target volume (aCTVHR) in high-grade glioma in a cellularity-dependent manner, the dosimetric effects of aCTVHR-targeted dose optimization were evaluated in two intensity-modulated radiation therapy (IMRT) plans. Diffusion-weighted magnetic resonance (MR) images and ADC maps were analyzed qualitatively and quantitatively to determine aCTVHR in a high-grade glioma with high cellularity. After confirming tumor malignancy using the average and minimum ADCs and ADC ratios, the aCTVHR with double- or triple-restricted water diffusion was defined on computed tomography images through image registration. Doses to the aCTVHR and CTV defined on T1-weighted MR images were optimized using a simultaneous integrated boost technique. The dosimetric benefits for CTVs and organs at risk (OARs) were compared using dose volume histograms and various biophysical indices in an ADC map-based IMRT (IMRTADC) plan and a conventional IMRT (IMRTconv) plan. The IMRTADC plan improved dose conformity up to 15 times, compared to the IMRTconv plan. It reduced the equivalent uniform doses in the visual system and brain stem by more than 10% and 16%, respectively. The ADC-based target differentiation and dose optimization may facilitate conformal dose distribution to the aCTVHR and OAR sparing in an IMRT plan.

Feasibility and Outcomes of Hypofractionated Simultaneous Integrated Boost-Intensity Modulated Radiotherapy for Malignant Gliomas: A Preliminary Report

PURPOSE: The aim of this study was to assess the feasibility and efficacy of hypofractionated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) using three-layered planning target volumes (PTV) for malignant gliomas. MATERIALS AND METHODS: We conducted a retrospective analysis of 12 patients (WHO grade IV-10; III-2) postoperatively treated with SIB-IMRT with concurrent temozolomide. Three-layered PTVs were contoured based on gadolinium-enhanced magnetic resonance imaging as follows; high risk PTV (H-PTV) as the area of surgical bed including residual gross tumor with a 0.5 cm margin; low risk PTV (L-PTV) as the area surrounding the high risk PTV with 1.5 cm margin; moderate risk PTV (M-PTV) as a line at one-third the distance from high risk PTV to low risk PTV. Total dose to high risk PTV was 70 Gy in 8 and 62.5 Gy in 4 patients. RESULTS: The median follow-up time was 52 months in surviving patients. The 2- and 5-year overall survival (OS) rates were 66.6% and 47.6%, respectively. The 2- and 5-year progression-free survival (PFS) rates were 57.1% and 45.7%, respectively. The median OS and PFS were 48 and 31 months, respectively. Six patients (50%) progressed: in-field only in one, out-field or disseminated in 4, and both in one patient. All patients completed planned treatments without a toxicity-related gap. Asymptomatic radiation necrosis was observed in 4 patients at post-radiotherapy 9-31 months. CONCLUSION: An escalated dose of hypofractionated SIB-IMRT using three-layered PTVs can be safely performed in patients with malignant glioma, and might contribute to better tumor control and survival.

Radioterapia de intensidad modulada: resultados preliminares de los primeros pacientes atendidos en Cuba / Intensity Modulated Radiotherapy: preliminary results of the first patients in Cuba

Introducción: la radioterapia de intensidad modulada es una técnica moderna donde se modula la intensidad de haz de radiaciones para irradiar el tejido tumoral y disminuir al máximo la dosis recibida por los tejidos sanos. El Instituto de Oncología y Radiobiología (INOR), pionero en emplear la técnica en Latinoamérica, presenta sus resultados preliminares. Métodos: se presentó un estudio prospectivo realizado en 31 pacientes a los cuales se les diagnosticó un tumor de cabeza y cuello y fueron tratados con radioterapia de intensidad modulada, desde mayo de 2008 hasta mayo de 2010. Resultados: las edades de los pacientes incluidos en el estudio estaban comprendidas entre los 45 y 70 años con una mediana de 58 años. Predominó el sexo masculino con 87 porciento. Las etapas clínicas localmente avanzadas fueron las más frecuentes. Con el empleo de esta técnica no hubo interrupción del tratamiento por toxicidades o complicaciones importantes. El 89 porciento de los pacientes mantiene controlada su enfermedad y solo 4 de ellos tuvieron recaída: 3, locorregionalmente y 1 a distancia. Las complicaciones más frecuentes durante el tratamiento fueron la radiomucositis, la disfagia y la disfonía, pero generalmente toleradas por los pacientes con el suministro de tratamientos de sostén. La xerostomía no se presentó en estos pacientes porque en la planificación de la técnica se protegen las parótidas como órganos de riesgo (OR). Conclusiones: el mayor control locorregional del tumor y la disminución de las complicaciones durante el tratamiento indican la superioridad de la técnica...

Introduction: the intensity modulated radiotherapy (IMRT) is a current technique where the beam radiations intensity to irradiate the tumoral tissue and to decrease at maximum the dose received by healthy tissues. The Institute of Oncology and Radiobiology (INOR), pioneer in the use of this technique in Latin America, offers its preliminary results. Methods: a prospective study was conducted in 31 patients diagnosed with a head and neck tumor treated with radiotherapy of modulated intensity from May, 2008 to May, 2010. Results: ages of patients included in present study were between 45-70 years with a mean of 58 years. There was predominance of male sex for a 87 percent. The clinical stages locally advances were the more frequent. With the use of this technique there was not interruption of treatment from toxicities or significant complications. The 89 percent of patients maintain controlled its diseases and only 4 of them had relapses: three in a loco-regional way and another one at distance. The more frequent complications during the treatment were the radio-mucositis, dysphagia and dysphonia, but in general were tolerated by patients with the supply of support treatment. The xerostomia wa not present in these patients due to in the planning of technique the parotid glands are protected like risk organs (RO). Conclusions: the great loco-regional control of tumor and the decrease of complications during treatment indicates the superiority of the technique...

Importance of contouring the cervical spine levels in initial intensity-modulated radiation therapy radiation for head and neck cancers: implications for re-irradiation.

Aim: To evaluate the maximum differential cervical spinal (C-spine) cord dose in intensity-modulated radiation therapy (IMRT) plans of patients undergoing radiotherapy for treatment of head and neck cancer. Materials and Methods: The C-spine of ten head and neck cancer patients that were planned using IMRT and each cervical vertebral body and the right and left sides was contoured by splitting the cord in the center. Dose-volume histograms (DVH) and maximum point doses were obtained for each contour and compared. Results: The dose to the cord varied with the location of the primary tumor but such variation was not consistently seen. This report provides information that is critical for planning reirradiation treatments. We recommend that contouring of the C-spine cord with IMRT should include outlining of each cervical cord level and identification of the right and the left sides of the cord on each plan.