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1.
Anticancer Res ; 41(4): 2101-2110, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813420

RESUMO

BACKGROUND/AIM: To evaluate if topical support therapy during static-intensity modulated radiotherapy (sIMRT) course is able to equal the characteristic minimum risk for radiation proctitis of Image-guided volumetric modulated arc therapy (IG-VMAT) treatment among localized prostate cancer patients. PATIENTS AND METHODS: Rectal toxicity data of the above patients were retrospectively collected throughout three different clinical periods at our Radiotherapy Deparment: from October 2011 to December 2012, prostate cancer patients were treated with sIMRT and in advance supported by means of daily topical corticosteroids; from January 2013 to November 2016, topical corticosteroids were replaced by daily hyaluronic acid enemas; from December 2016 to May 2018 eligible patients were treated with newly introduced IG-VMAT supported by only on-demand topical corticosteroids. RESULTS: Among 359 eligible patients, IG-VMAT was proven generally more effective than sIMRT supported by topical medications in terms of proctitis reduction, although without clinical and practical relevance. CONCLUSION: Topical medications might have a role in radiation proctitis prevention.


Assuntos
Anti-Inflamatórios/administração & dosagem , Proctite/prevenção & controle , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Radioterapia de Intensidade Modulada , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Beclometasona/administração & dosagem , Enema/métodos , Humanos , Ácido Hialurônico/administração & dosagem , Itália , Masculino , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Proctite/etiologia , Neoplasias da Próstata/patologia , Hipofracionamento da Dose de Radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
2.
Anticancer Res ; 41(4): 2141-2145, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813425

RESUMO

BACKGROUND/AIM: We compared the outcome of docetaxel, cisplatin, and 5-fluorouracil as combination chemoradiotherapy (DCF-RT) for unresectable locally advanced thoracic esophageal cancer (EC) with that of cisplatin (CDDP) and 5-fluorouracil (5-FU) as combination chemoradiotherapy (CF-RT) in clinical settings. PATIENTS AND METHODS: Seventy-three patients with unresectable locally advanced thoracic EC were included in this study. CF (n=38) consisted of intravenous CDDP at 70 mg/m2 (day 1) and 5-FU at 700 mg/m2 (days 1 to 4), repeated every four weeks for two cycles. DCF (n=35) consisted of intravenous docetaxel at 50 mg/m2 (day 1), CDDP at 60 mg/m2 (day 1), and 5-FU at 600 mg/m2 (days 1 to 4), repeated every four weeks for two cycles. Patients were irradiated with 60 Gy in 30 fractions. RESULTS: The overall complete response (CR) rate of DCF-RT was significantly higher than that of CF-RT (36.7% vs. 3.7%, p=0.003). The 3-year overall survival (OS) rate of DCF-RT was significantly higher than that of CF-RT (32.8% vs. 8.5%, p<0.001). CONCLUSION: DCF-RT demonstrated a higher CR rate and OS for unresectable locally advanced thoracic EC than CF-RT.


Assuntos
Quimiorradioterapia , Cisplatino/administração & dosagem , Docetaxel/administração & dosagem , Neoplasias Esofágicas/terapia , Fluoruracila/administração & dosagem , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Cisplatino/efeitos adversos , Progressão da Doença , Docetaxel/efeitos adversos , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Fluoruracila/efeitos adversos , Humanos , Japão/epidemiologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
3.
Ann R Coll Surg Engl ; 103(3): 191-196, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33645271

RESUMO

INTRODUCTION: Squamous cell carcinoma is the most common variant of anal malignancy. Certain disease-related factors have been established in determining survival. These include tumour size, differentiation and nodal involvement. Other factors such as HIV status, human papillomavirus infection, smoking and socioeconomic disparity may have important roles, however few data are available on the UK population. We aim to correlate social deprivation and survival of anal cancer patients at a tertiary centre. MATERIALS AND METHODS: All consecutive cases diagnosed with anal squamous cell carcinoma and treated as per local protocol between July 2010 and April 2017 were included. The pathological and demographical details were collected from a prospectively maintained database. Socioeconomic deprivation was defined for each postcode using the Index of Multiple Deprivation decile compiled by local governments in England. Survival was estimated using Kaplan-Meier analysis and Cox regression was used to investigate the effect of different factors on overall survival. RESULTS: A total of 129 patients with anal squamous cell carcinoma over a median follow-up of 43 months were included. Overall survival for the entire patient cohort was 87.7% (95% confidence interval, CI, 82.0-93.7%), 75.5% (95% CI 67.5-84.5%) and 68.9% (95% CI 59.7-79.6%) at one year, three years and five years, respectively. On multivariate analysis, Index of Multiple Deprivation and income do not significantly influence overall survival (p = 0.79, hazard ratio, HR, 1.07; 95% CI 0.61-1.63), (p = 0.99, HR=1.00; 95% CI 0.61-1.63), respectively. Increased risk of death was observed for male sex (p = 0.02, HR=2.80; 95% CI 1.02-5.50) and larger tumour size (p = 0.01, HR=1.64; 95% CI 1.12-2.41). CONCLUSION: In contrast to US studies, there is little difference in survival between the least deprived and most deprived groups. We attribute this to equal access to intensity-modulated radiation therapy-based chemoradiotherapy. Thus, a highly effective treatment made available to all mitigates any survival difference between socioeconomic groups.


Assuntos
Neoplasias do Ânus/mortalidade , Carcinoma de Células Escamosas/mortalidade , Status Econômico , Classe Social , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Ânus/patologia , Neoplasias do Ânus/terapia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Estudos de Coortes , Feminino , Humanos , Renda , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Radioterapia de Intensidade Modulada , Características de Residência , Fatores Sexuais , Taxa de Sobrevida , Carga Tumoral , Reino Unido
4.
Magy Onkol ; 65(1): 14-22, 2021 Mar 17.
Artigo em Húngaro | MEDLINE | ID: mdl-33730112

RESUMO

In treatment planning of small-sized lung tumors treated with stereotactic body radiotherapy (SBRT) in Eclipse treatment planning system with the Normal tissue objective (NTO) tool sharp dose gradients beyond the target volume can be achived. NTO has 5 variable parameters, so it is difficult to know which settings are optimal. The purpose of this study was to characterize the effects of changing NTO parameters on lung SBRT dose distributions. Ten lung SBRT cases were replanned using different NTO parameters. Dose calculation was performed using AAA and AXB algorithms as well. Differences between AAA and AXB plans were statistically significant. Plans were evaluated based on plan quality metrics. According to this analysis the fall-off of 0.15 and the priority of 500 have satisfied our institutional criteria best. Using NTO during planning is recommended in clinical practice.


Assuntos
Neoplasias Pulmonares , Radiocirurgia , Radioterapia de Intensidade Modulada , Algoritmos , Humanos , Pulmão , Neoplasias Pulmonares/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
5.
Magy Onkol ; 65(1): 23-29, 2021 Mar 17.
Artigo em Húngaro | MEDLINE | ID: mdl-33730113

RESUMO

The aim of the study was to compare the different stereotactic treatment plans and dose calculation algorithms for small targets with film dosimetry in anthropomorphic phantom. Treatment plans were prepared for multiple targets with single setup isocenter. Plans for three different irradiation techniques were generated using conformal arc with four non-coplanar arcs, RapidArc with two coplanar full arcs and RapidArc with four non-coplanar arcs in the Varian Eclipse v13.7.16 TPS. Conformal arc and RapidArc plans were calculated using AAA, Acuros XBDm and XBDw algorithms. Conformity index, gradient index and dose maximum were calculated for all PTVs. All measurements were made on the Varian TrueBeam linear accelerator. Comparison between computed and measured dose distributions was performed with gamma evaluation criteria of 3%, 3 mm; 3%, 1 mm and 2%, 2 mm. According to our results, the Eclipse AAA and AXB algorithms provide accurate dose distributions for homogeneous cranial irradiation.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Radioterapia de Intensidade Modulada , Algoritmos , Neoplasias Encefálicas/radioterapia , Humanos , Aceleradores de Partículas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
6.
Br J Radiol ; 94(1120): 20201014, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33733813

RESUMO

OBJECTIVES: In real-time portal dosimetry, thresholds are set for several measures of difference between predicted and measured images, and signals larger than those thresholds signify an error. The aim of this work is to investigate the use of an additional composite difference metric (CDM) for earlier detection of errors. METHODS: Portal images were predicted for the volumetric modulated arc therapy plans of six prostate patients. Errors in monitor units, aperture opening, aperture position and path length were deliberately introduced into all 180 segments of the treatment plans, and these plans were delivered to a water-equivalent phantom. Four different metrics, consisting of central axis signal, mean image value and two image difference measures, were used to identify errors, and a CDM was added, consisting of a weighted power sum of the individual metrics. To optimise the weights of the CDM and to evaluate the resulting timeliness of error detection, a leave-pair-out strategy was used. For each combination of four patients, the weights of the CDM were determined by an exhaustive search, and the result was evaluated on the remaining two patients. RESULTS: The median segment index at which the errors were identified was 87 (range 40-130) when using all of the individual metrics separately. Using a CDM as well as multiple separate metrics reduced this to 73 (35-95). The median weighting factors of the four metrics constituting the composite were (0.15, 0.10, 0.15, 0.00). Due to selection of suitable threshold levels, there was only one false positive result in the six patients. CONCLUSION: This study shows that, in conjunction with appropriate error thresholds, use of a CDM is able to identify increased image differences around 20% earlier than the separate measures. ADVANCES IN KNOWLEDGE: This study shows the value of combining difference metrics to allow earlier detection of errors during real-time portal dosimetry for volumetric modulated arc therapy treatment.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Masculino , Imagens de Fantasmas , Próstata/diagnóstico por imagem , Radiometria , Dosagem Radioterapêutica , Estudos Retrospectivos
7.
Anticancer Res ; 41(3): 1587-1592, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33788753

RESUMO

BACKGROUND/AIM: Modern intensity-modulated radiotherapy (IMRT) is frequently applied to treat patients with nasal cavity and paranasal sinus (NC/PNS) malignancies. PATIENTS AND METHODS: One hundred and four patients who underwent radiotherapy (RT) between 1994 and 2020 were recognized. This analysis compared conventional-radiotherapy (CRT) and image-guided IMRT outcomes for NC/PNS malignancies. RESULTS: The median follow-up was 69 months. Eighty-eight patients (85%) were managed with image-guided IMRT. The median initial radiation dose was 65 Gy, with 68 Gy applied for patients treated with primary RT versus 63 Gy applied for adjuvant therapy (p=0.1). The 5-year locoregional control (LRC) was 85%. The locoregional recurrence rate was 18% following IMRT versus 31% in the 2D/3D-conventional RT group (p=0.09). Moreover, IMRT was associated with a lower inner-ear toxicity rate (8% vs. 20%, respectively; p=0.045). CONCLUSION: IMRT appears to be linked with higher LRC and lower inner-ear acute toxicities compared to conventional RT.


Assuntos
Cavidade Nasal , Neoplasias Nasais/radioterapia , Neoplasias dos Seios Paranasais/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Dosagem Radioterapêutica , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos
8.
Ann R Coll Surg Engl ; 103(3): e85-e87, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33645266

RESUMO

Epidermolysis bullosa simplex (EBS) is a debilitating condition affecting the skin and mucous membranes that is characterised by frequent ulceration and blistering on trivial trauma. In EBS, oral cavity mucosal injuries lead to a high propensity for developing squamous cell carcinomas. Locally advanced tongue carcinoma arising in this background presents a challenging therapeutic conundrum. To our knowledge, this is the first case of aggressive locally advanced tongue carcinoma that has developed sporadically in a patient with EBS and no family history. Routine screening of oral mucosal lesions will lead to early detection and timely management of this debilitating condition.


Assuntos
Epidermólise Bolhosa Simples/diagnóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias da Língua/diagnóstico por imagem , Adulto , Progressão da Doença , Epidermólise Bolhosa Simples/complicações , Epidermólise Bolhosa Simples/patologia , Evolução Fatal , Humanos , Masculino , Estadiamento de Neoplasias , Radiodermatite/etiologia , Radioterapia de Intensidade Modulada/efeitos adversos , Carcinoma de Células Escamosas de Cabeça e Pescoço/complicações , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , Estomatite/etiologia , Neoplasias da Língua/complicações , Neoplasias da Língua/patologia , Neoplasias da Língua/radioterapia
9.
Br J Radiol ; 94(1119): 20201031, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33529057

RESUMO

OBJECTIVE: To study dosimetric impact of random spot positioning errors on the clinical pencil beam scanning proton therapy plans. METHODS AND MATERIALS: IMPT plans of 10 patients who underwent proton therapy for tumors in brain or pelvic regions representing small and large volumes, respectively, were included in the study. Spot positioning errors of 1 mm, -1 mm or ±1 mm were introduced in these clinical plans by modifying the geometrical co-ordinates of proton spots using a script in the MATLAB programming environment. Positioning errors were simulated to certain numbers of (20%, 40%, 60%, 80%) randomly chosen spots in each layer of these treatment plans. Treatment plans with simulated errors were then imported back to the Raystation (Version 7) treatment planning system and the resultant dose distribution was calculated using Monte-Carlo dose calculation algorithm.Dosimetric plan evaluation parameters for target and critical organs of nominal treatment plans delivered for clinical treatments were compared with that of positioning error simulated treatment plans. For targets, D95% and D2% were used for the analysis. Dose received by optic nerve, chiasm, brainstem, rectum, sigmoid, and bowel were analyzed using relevant plan evaluation parameters depending on the critical structure. In case of intracranial lesions, the dose received by 0.03 cm3 volume (D0.03 cm3) was analyzed for optic nerve, chiasm and brainstem. In rectum, the volume of it receiving a dose of 65 Gy(RBE) (V65) and 40 Gy(RBE) (V40) were compared between the nominal and error introduced plans. Similarly, V65 and V63 were analyzed for Sigmoid and V50 and V15 were analyzed for bowel. RESULTS: The maximum dose variation in PTV D95% (1.88 %) was observed in a brain plan in which the target volume was the smallest (2.7 cm3) among all 10 plans included in the study. This variation in D95% drops down to 0.3% for a sacral chordoma plan in which the PTV volume is significantly higher at 672 cm3. The maximum difference in OARs in terms of absolute dose (D0.03 cm3) was found in left optic nerve (9.81%) and the minimum difference was observed in brainstem (2.48%). Overall, the magnitude of dose errors in chordoma plans were less significant in comparison to brain plans. CONCLUSION: The dosimetric impact of different error scenarios in spot positioning becomes more prominent for treatment plans involving smaller target volume compared to plans involving larger target volumes. ADVANCES IN KNOWLEDGE: Provides information on the dosimetric impact of various possible spot positioning errors and its dependence on the tumor volume in intensity modulated proton therapy.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Pélvicas/radioterapia , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Método de Monte Carlo , Dosagem Radioterapêutica , Reprodutibilidade dos Testes
10.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(1): 109-113, 2021 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-33522189

RESUMO

Clinically, beam matching can greatly improve the flexibility and efficiency of treating patients between different medical electron linacs. However, in addition to the regular quality assurance (QA) test of the machine performance of linacs, there is still a lack of comprehensive evaluation of the clinical radiotherapy performance of beam-matched linacs. In this paper, the performance of volumetric modulated arc therapy (VMAT) between three closely matched linacs was evaluated by statistical process control (SPC) technology. It was found that the average and median γ passing rates of the VMAT QA processes of the three linacs had little difference, but the process capability levels were at three different levels. The results show that SPC technology can effectively evaluate the performance of beam matching for medical electron linacs, improve the patient-specific VMAT QA processes, and guide clinical decision-making.


Assuntos
Elétrons , Aceleradores de Partículas , Garantia da Qualidade dos Cuidados de Saúde , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada
11.
Lancet Oncol ; 22(3): 381-390, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33600761

RESUMO

BACKGROUND: The role of surgery compared with reirradiation in the primary treatment of patients with resectable, locally recurrent nasopharyngeal carcinoma (NPC) who have previously received radiotherapy is a matter of debate. In this trial, we compared the efficacy and safety outcomes of salvage endoscopic surgery versus intensity-modulated radiotherapy (IMRT) in patients with resectable locally recurrent NPC. METHODS: This multicentre, open-label, randomised, controlled, phase 3 trial was done in three hospitals in southern China. We included patients aged 18-70 years with a Karnofsky Performance Status score of at least 70 who were histopathologically diagnosed with undifferentiated or differentiated, non-keratinising, locally recurrent NPC with tumours confined to the nasopharyngeal cavity, the post-naris or nasal septum, the superficial parapharyngeal space, or the base wall of the sphenoid sinus. Eligible patients were randomly assigned (1:1) to receive either endoscopic nasopharyngectomy (ENPG group) or IMRT (IMRT group). Randomisation was done manually using a computer-generated random number code and patients were stratified by treatment centre. Treatment group assignment was not masked. The primary endpoint was overall survival, compared between the groups at 3 years. Efficacy analyses were done by intention to treat. Safety analysis was done in patients who received treatment according to the treatment they actually received. This trial was prospectively registered at the Chinese Clinical Trial Registry, ChiCTR-TRC-11001573, and is currently in follow-up. FINDINGS: Between Sept 30, 2011, and Jan 16, 2017, 200 eligible patients were randomly assigned to receive either ENPG (n=100) or IMRT (n=100). At a median follow-up of 56·0 months (IQR 42·0-69·0), 74 patients had died (29 [29%] of 100 patients in the ENPG group and 45 [45%] of 100 patients in the IMRT group). The 3-year overall survival was 85·8% (95% CI 78·9-92·7) in the ENPG group and 68·0% (58·6-77·4) in the IMRT group (hazard ratio 0·47, 95% CI 0·29-0·76; p=0·0015). The most common grade 3 or worse radiation-related late adverse event was pharyngeal mucositis (in five [5%] of 99 patients who underwent ENPG and 26 [26%] of 101 patients who underwent IMRT). Five [5%] of the 99 patients who underwent ENPG and 20 [20%] of the 101 patients who underwent IMRT died due to late toxic effects specific to radiotherapy; attribution to previous radiotherapy or trial radiotherapy is unclear due to the long-term nature of radiation-related toxicity. INTERPRETATION: Endoscopic surgery significantly improved overall survival compared with IMRT in patients with resectable locally recurrent NPC. These results suggest that ENPG could be considered as the standard treatment option for this patient population, although long-term follow-up is needed to further determine the efficacy and toxicity of this strategy. FUNDING: Sun Yat-sen University Clinical Research 5010 Program.


Assuntos
Carcinoma Nasofaríngeo/mortalidade , Neoplasias Nasofaríngeas/mortalidade , Cirurgia Endoscópica por Orifício Natural/mortalidade , Recidiva Local de Neoplasia/mortalidade , Radioterapia de Intensidade Modulada/mortalidade , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/radioterapia , Carcinoma Nasofaríngeo/cirurgia , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/radioterapia , Neoplasias Nasofaríngeas/cirurgia , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Taxa de Sobrevida
12.
Artigo em Japonês | MEDLINE | ID: mdl-33473076

RESUMO

PURPOSE: Knowledge-based planning (KBP) has disadvantages of high monitor unit (MU) and complex multi-leaf collimator (MLC) motion. We investigated the optimal aperture shape controller (ASC) level for the KBP to reduce these factors in volumetric modulated arc therapy (VMAT) for prostate cancer. METHODS: The KBP model was created based on 51 clinical plans (CPs) of patients who underwent the VMAT for prostate cancer. Another 10 CPs were selected randomly, and the KBPs with/without ASC, changed stepwise from very low (KBP-VL) to very high (KBP-VH), were performed with a single auto-optimization. The parameters of dose-volume histograms (DVHs) and MLC performance metrics were evaluated. We obtained the modulation complexity score for VMAT (MCSv), closed leaf score (CLS), small aperture score (SAS), leaf travel (LT), and total MU. RESULTS: The ASC did not affect the DVH parameters negatively. The following comparisons of MLC performance were obtained (KBP vs. KBP-VL vs. KBP-VH, respectively): 0.25 vs. 0.27 vs. 0.30 (MCSv), 0.19 vs. 0.18 vs. 0.16 (CLS), 0.50 vs. 0.45 vs. 0.40 (SAS10 mm), 0.73 vs. 0.68 vs. 0.63 (SAS20 mm), 768.35 mm vs. 671.50 mm vs. 551.32 mm (LT), and 672.87 vs. 642.36 vs. 607.59 (MU). There were significant differences between KBP and KBP-VH for MCSv and LT (p<0.05). CONCLUSIONS: The KBP using an ASC set to the very high level could reduce the complexity of MLC motion significantly more without deterioration of the DVH parameters compared with the KBP in VMAT for prostate cancer.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Humanos , Bases de Conhecimento , Masculino , Neoplasias da Próstata/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
13.
Medicine (Baltimore) ; 100(1): e24266, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429836

RESUMO

BACKGROUND: Intensity-modulated radiotherapy (IMRT) is a widely used irradiation technique in rectal cancer patients. We aimed to compare 4 different IMRT plans with 3-dimensional conformal radiotherapy (3D-CRT) considering organs at risk (OARs) in patients with rectal carcinoma. METHODS: This retrospective study included 27 rectal cancer patients who were irradiated preoperatively between January 2016 and December 2018. Five different plans (4-field 3D-CRT in 2 phases, 7-field IMRT in 2 phases, 9-field IMRT in 2 phases, 7-field simultaneous integrated boost [SIB] IMRT, and 9-field SIB IMRT) were generated for each patient. Comparison of 5 different plans according to bladder and bilateral femoral head mean doses, bladder V40, bilateral femoral head V40, and small bowel V35 values were evaluated. RESULTS: Most of the OAR parameters significantly favored IMRT plans compared to the 3D-CRT plan. The largest difference was observed in bladder V40 values (reduction of V40 value up to 51.2% reduction) in favor of IMRT. In addition, SIB plans showed significantly better reduction in OARs than phase plans except for small bowel V35 values. CONCLUSIONS: IMRT plans reduced almost all the OARs doses compared with the 3D-CRT plan in rectal cancer patients. Furthermore, SIB plans demonstrated lower OAR doses than the phase plans. IMRT techniques, especially SIB plans, reduce OAR doses and provide safer doses for the treatment of rectal carcinoma.


Assuntos
Adenocarcinoma/radioterapia , Neoplasias Retais/radioterapia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Período Pré-Operatório , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Estudos Retrospectivos
14.
BMC Neurol ; 21(1): 30, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33468088

RESUMO

BACKGROUND: Hypothyroidism (HT) and carotid artery stenosis (CAS) are complications of radiotherapy (RT) in patients with head and neck cancer (HNC). The impact of post-RT HT on CAS progression remains unclear. METHODS: Between 2013 and 2014, HNC patients who had ever received RT and were under regular follow-up in our hospital were initially screened. Patients were categorized into euthyroid (EU) and HT groups. Details of RT and HNC were recorded. Total plaque scores and degrees of CAS were measured during annual extracranial duplex follow-up. Patients were monitored for CAS progression to > 50 % stenosis or ischemic stroke (IS). Cumulative time to CAS progression and IS between the 2 groups were compared. Data were further analyzed based on the use or nonuse of thyroxine of the HT group. RESULTS: 333 HNC patients with RT history were screened. Finally, 216 patients were recruited (94 and 122 patients in the EU and HT groups). Patients of the HT group received higher mean RT doses (HT vs. EU; 7021.55 ± 401.67 vs. 6869.69 ± 425.32 centi-grays, p = 0.02). Multivariate Cox models showed comparable CAS progression (p = 0.24) and IS occurrence (p = 0.51) between the 2 groups. Moreover, no significant difference was observed in time to CAS progression (p = 0.49) or IS (p = 0.31) among patients with EU and HT using and not using thyroxine supplement. CONCLUSIONS: Our results did not demonstrate significant effects of HT and thyroxine supplementation on CAS progression and IS incidence in patients with HNC after RT.


Assuntos
Estenose das Carótidas/etiologia , Irradiação Craniana/efeitos adversos , Neoplasias de Cabeça e Pescoço/radioterapia , Hipotireoidismo/etiologia , Lesões por Radiação/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/epidemiologia , Feminino , Humanos , Hipotireoidismo/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Radioterapia de Intensidade Modulada/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia
15.
Br J Radiol ; 94(1119): 20201354, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33481637

RESUMO

OBJECTIVES: This multicentric study was carried out to investigate the impact of small field output factors (OFs) inaccuracies on the calculated dose in volumetric arctherapy (VMAT) radiosurgery brain plans. METHODS: Nine centres, realised the same five VMAT plans with common planning rules and their specific clinical equipment Linac/treatment planning system commissioned with their OFs measured values (OFbaseline). In order to simulate OFs errors, two new OFs sets were generated for each centre by changing only the OFs values of the smallest field sizes (from 3.2 × 3.2 cm2 to 1 × 1 cm2) with well-defined amounts (positive and negative). Consequently, two virtual machines for each centre were recommissioned using the new OFs and the percentage dose differences ΔD (%) between the baseline plans and the same plans recalculated using the incremented (OFup) and decremented (OFdown) values were evaluated. The ΔD (%) were analysed in terms of planning target volume (PTV) coverage and organs at risk (OARs) sparing at selected dose/volume points. RESULTS: The plans recalculated with OFdown sets resulted in higher variation of doses than baseline within 1.6 and 3.4% to PTVs and OARs respectively; while the plans with OFup sets resulted in lower variation within 1.3% to both PTVs and OARs. Our analysis highlights that OFs variations affect calculated dose depending on the algorithm and on the delivery mode (field jaw/MLC-defined). The Monte Carlo (MC) algorithm resulted significantly more sensitive to OFs variations than all of the other algorithms. CONCLUSION: The aim of our study was to evaluate how small fields OFs inaccuracies can affect the dose calculation in VMAT brain radiosurgery treatments plans. It was observed that simulated OFs errors, return dosimetric calculation accuracies within the 3% between concurrent plans analysed in terms of percentage dose differences at selected dose/volume points of the PTV coverage and OARs sparing. ADVANCES IN KNOWLEDGE: First multicentre study involving different Planning/Linacs about undetectable errors in commissioning output factor for small fields.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos , Encéfalo/diagnóstico por imagem , Simulação por Computador , Humanos , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Incerteza
16.
Cancer Radiother ; 25(2): 191-199, 2021 Apr.
Artigo em Francês | MEDLINE | ID: mdl-33402287

RESUMO

PURPOSE: In breast cancer, radiotherapy is an essential component of the treatment. However, indications of irradiation of the internal mammary chain and axillary area are debatables. Axillary recurrence in patients with invasive breast carcinoma remains an issue. Currently, the substitution of axillary lymph node dissection by sentinel node biopsy leads to revisit the role of axillary irradiation. Breast irradiation including level I, II and III might decrease the risk of axillary recurrence. MATERIAL AND METHODS: A literature search was performed in PubMed and the Cochrane library to identify articles publishing data regarding dose-volume analysis of axillary levels in breast irradiation aiming to determine the potential therapeutic implications. RESULTS: Eleven articles were retained. A total of 375 treatment plans were analyzed. The results concerning the irradiation technique, initial dose prescribed to breast, delineated volumes and dose received at axillary levels were heterogeneous. The average dose delivered to axilla levels I-III with 3D-conformal radiotherapy using standard fields were between 24Gy and 43.5Gy, 3Gy and 32.5Gy and between 1.0Gy and 20.5Gy respectively. The average doses delivered to axilla levels I-III with 3D-conformal radiotherapy using high tangential fields were between 38Gy and 49.7Gy, 11Gy and 47.1Gy and 5Gy 38.7Gy, 32.1Gy and 5Gy (result available for only one study) respectively. Finally, the average doses delivered to axilla levels I-III with intensity modulated radiation therapy were between 14.5Gy and 42.6Gy, 3.4Gy and 35Gy and between 1.2Gy and 25.5Gy respectively. CONCLUSIONS: Incidental axillary dose seems insufficient to be therapeutic regardless of the irradiation technique. There are meaningful differences between intensity modulated radiation therapy and 3D-conformal radiotherapy.


Assuntos
Neoplasias da Mama/radioterapia , Irradiação Linfática/métodos , Axila , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Feminino , Humanos , Mastectomia , Terapia Neoadjuvante/métodos , Recidiva Local de Neoplasia/prevenção & controle , Recidiva Local de Neoplasia/radioterapia , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Radioterapia Conformacional/normas , Radioterapia de Intensidade Modulada/métodos , Radioterapia de Intensidade Modulada/normas , Biópsia de Linfonodo Sentinela
17.
Cancer Radiother ; 25(1): 32-38, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33402292

RESUMO

PURPOSE: To evaluate attenuation of the totally implantable vascular access device (TIVAD) and assess its clinical and dosimetric impact on radiotherapy (RT) of lymphoma patients. MATERIALS AND METHODS: The first part of the study consisted of an in vitro approach by irradiating the TIVAD with different electron and photon energies. The attenuation data measured were compared with data calculated by our treatment planning system. All patients treated by radiotherapy for Hodgkin's lymphoma with their TIVAD in the target volume were then reviewed to assess the clinical outcome and dosimetric comparison using different plan metrics. All patients were treated by 3D conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy delivered by Helical Tomotherapy (HT). RESULTS: Nineteen patients treated for stage I-III HL were studied. Seven patients were treated exclusively on the side of TIVAD and 12 were treated bilaterally. Median prescription dose was 30Gy. No significant clinical or dosimetric differences were observed between the side of the TIVAD and the contralateral side in patients treated bilaterally. HT resulted in a significantly higher conformity index (P<0.0022) and a significantly lower healthy tissue coverage (P=0.0008) than 3DCRT. The observed attenuation was 79% for 6 MeV, 59% for 9 MeV, and 46% for 12 MeV for electrons and 9% for 4 MV, 8% for 6 MV, 5% for 10 MV and 15 MV and 3% for 20 MV for X photons. CONCLUSION: TIVADs induce significant beam attenuation when using electrons, which can be overcome by using high-energy photons or by creating an exclusion zone in when HT is used.


Assuntos
Doença de Hodgkin/radioterapia , Radioterapia Conformacional/métodos , Dispositivos de Acesso Vascular , Adulto , Elétrons/uso terapêutico , Feminino , Doença de Hodgkin/patologia , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Terapia com Prótons , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Adulto Jovem
18.
Cancer Radiother ; 25(1): 39-44, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33419607

RESUMO

PURPOSE: Chemoradiotherapy (CRT) is considered as a standard treatment for unresectable and inoperable esophageal cancer (EC) patients. However, no consensus has been reached regarding the optimal synchronous chemotherapy regimen and the best combination of radiotherapy and chemotherapy. The aim of this study was to evaluate the efficacy and toxicity of raltitrexed plus cisplatin and docetaxel plus cisplatin to find a safe and effective concurrent chemotherapy schedule. PATIENTS AND METHODS: Our retrospective study included 151 EC patients treated with raltitrexed and cisplatin (RP) (n=90) or docetaxel and cisplatin (DP) (n=61) from 2011 till 2018. Survival outcomes and treatment related toxicity were analyzed between the two groups. RESULTS: PFS and OS were 18 and 34 months in the RP group, while 13 and 20 months in the DP group (P=0.118 and P=0.270). The 1-, 2-, 3-year survival rates of the RP group were 71.1, 55.4 and 46.4%. For the DP group, these were 63.9, 44.3 and 37.6%, respectively. Compared with DP group, RP group received a superior CR rate (68.9% versus 52.5%, P=0.041). There was a trend that the total number of toxic reactions in RP group was lower than that in DP group (P=0.058). CONCLUSIONS: Even RP and DP groups have the similar survival outcomes and toxicity, raltitrexed/cisplatin get a higher complete response rate. Our study suggests that raltitrexed combined with cisplatin is a safe and effective concurrent chemotherapy regimen and it might be used as an alternative for cisplatin/5-FU and cisplatin/docetaxel in CCRT for EC patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia/métodos , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas do Esôfago/terapia , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimiorradioterapia/efeitos adversos , Cisplatino/administração & dosagem , Docetaxel/administração & dosagem , Neoplasias Esofágicas/mortalidade , Carcinoma de Células Escamosas do Esôfago/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quinazolinas/administração & dosagem , Radioterapia de Intensidade Modulada/efeitos adversos , Análise de Regressão , Estudos Retrospectivos , Taxa de Sobrevida , Tiofenos/administração & dosagem , Resultado do Tratamento
19.
Phys Med Biol ; 65(24): 24TR05, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33438582

RESUMO

In the late 1980s, a new technique was proposed that would revolutionize radiotherapy. Now referred to as intensity-modulated radiotherapy, it is at the core of state-of-the-art photon beam delivery techniques, such as helical tomotherapy and volumetric modulated arc therapy. Despite over two decades of clinical application, there are still no established guidelines on the calibration of dynamic modulated photon beams. In 2008, the IAEA-AAPM work group on nonstandard photon beam dosimetry published a formalism to support the development of a new generation of protocols applicable to nonstandard beam reference dosimetry (Alfonso et al 2008 Med. Phys. 35 5179-86). The recent IAEA Code of Practice TRS-483 was published as a result of this initiative and addresses exclusively small static beams. But the plan-class specific reference calibration route proposed by Alfonso et al (2008 Med. Phys. 35 5179-86) is a change of paradigm that is yet to be implemented in radiotherapy clinics. The main goals of this paper are to provide a literature review on the dosimetry of nonstandard photon beams, including dynamic deliveries, and to discuss anticipated benefits and challenges in a future implementation of the IAEA-AAPM formalism on dynamic photon beams.


Assuntos
Fótons/uso terapêutico , Radiometria/normas , Radioterapia de Intensidade Modulada , Calibragem , Humanos , Planejamento da Radioterapia Assistida por Computador , Padrões de Referência
20.
Anticancer Res ; 41(1): 417-427, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33419839

RESUMO

BACKGROUND/AIM: The use of intensity-modulated radiation therapy (IMRT) in the treatment of breast cancer is increasing worldwide. Despite clear benefits concerning normal tissue sparing and dose homogeneity, the effects of breathing motion and setup error during breast IMRT should be considered. This study aimed to assess the dosimetric impact of respiratory motion on breast IMRT using four-dimensional (4D) dose calculations. PATIENTS AND METHODS: Multiple computed tomography datasets acquired in three representative respiratory amplitudes, were retrospectively re-planned. Based on the reference dose distribution (RDD), motion-adjusted dose distributions (MDD) were recalculated. All 4D dose distributions were calculated by the voxel-based accumulation of RDD and MDD using five temporal probabilities. The dosimetric parameters of the 4D plans were compared to those of RDD. RESULTS: The dosimetric parameters of the planning target volume (PTV) were not significantly different between the RDD and 4D plans. Of the parameters of tumor bed (TB) simultaneous-integrated boost (SIB), the mean dose and V95% for the 4D plans were significantly reduced compared to those of RDD, and the percentage difference in the TB V95% ranged from -1.1% to -5.7% (p<0.05). CONCLUSION: The breast IMRT plan was robust against respiratory motion during tidal breathing. However, special considerations should be made when designing the TB SIB.


Assuntos
Neoplasias da Mama/radioterapia , Movimento (Física) , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Respiração , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem , Radioterapia de Intensidade Modulada/métodos , Radioterapia de Intensidade Modulada/normas , Tomografia Computadorizada por Raios X
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