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1.
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
2.
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
3.
Eur Rev Med Pharmacol Sci ; 24(23): 12480-12489, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33336767

RESUMO

COVID-19 disease is one of the biggest public health challenges in Italy and global healthcare facilities, including radiotherapy departments, faced an unprecedented emergency. Cancer patients are at higher risk of COVID-19 infection because of their immunosuppressive state caused by both tumor itself and anticancer therapy adopted. In this setting, the radiation therapy clinical decision-making process has been partly reconsidered; thus, to reduce treatment duration and minimize infection risk during a pandemic, hypofractionated regimens have been revised. Moreover, telemedicine shows its helpfulness in the radiotherapy field, and patients get the supportive care they need minimizing their access to hospitals. This review aims to point out the importance of hypofractionated RT and telemedicine in cancer patient management in the COVID-19 era.


Assuntos
Neoplasias/radioterapia , Hipofracionamento da Dose de Radiação , Radioterapia (Especialidade)/métodos , Radioterapia/métodos , Telemedicina/métodos , Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Braquiterapia/métodos , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/radioterapia , Tomada de Decisão Clínica , Assistência à Saúde , Feminino , Humanos , Masculino , Guias de Prática Clínica como Assunto , Neoplasias da Próstata/radioterapia , Radiocirurgia/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Tempo para o Tratamento
4.
Lancet Child Adolesc Health ; 4(11): 846-852, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33068550

RESUMO

For decades, radiotherapy with two opposing photon beams has been the standard technique used to cover the flank target volume in paediatric patients with renal tumours. Nowadays, many institutes are implementing advanced radiotherapy techniques that spare healthy tissue. To decrease the radiotherapy dose to healthy structures while preserving oncological efficacy, the conventional approach of flank irradiation has been adapted into a guideline for highly conformal flank target-volume delineation by paediatric radiation oncologists and representatives of the International Society of Paediatric Oncology's Renal Tumour Study Group (SIOP-RTSG) board during four live international consensus meetings. The consensus was refined by delineation exercises and videoconferences by ten collaborating paediatric radiation oncologists. The final guideline includes eight chronological steps to generate the tumour bed and clinical, internal, and planning target volumes, and it describes the optional use of surgical clips to optimise treatment planning. This guideline will be added into the radiotherapy guideline of the UMBRELLA SIOP-RTSG protocol for paediatric renal tumours to improve international consistency of highly conformal flank target-volume delineation.


Assuntos
Neoplasias Renais/radioterapia , Tratamentos com Preservação do Órgão/métodos , Radioterapia Conformacional , Criança , Consenso , Humanos , Neoplasias Renais/patologia , Guias de Prática Clínica como Assunto , Saúde Radiológica , Radioterapia Conformacional/métodos , Radioterapia Conformacional/tendências
5.
Br J Radiol ; 93(1115): 20190633, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32970475

RESUMO

OBJECTIVES: Tumors of the lacrimal sac are rare and life-threatening. Because of their rarity, no extensive clinical data on their management and prognosis exist. We investigated the application of definitive radiation therapy and its outcome in patients with lacrimal sac squamous cell carcinoma (LSSCC). METHODS: We retrospectively studied 17 patients with LSSCC at a single institution between 2003 and 2017. All the patients were treated with definitive radiotherapy, and 11 patients were delivered with cisplatin-based chemotherapy. The patients' clinical records were reviewed for symptoms, pathological types, the volume and dosimetry of the tumors and their adjacent structures, radiation coverage of lymph node drainage areas, treatment outcomes, and complications from definitive radiotherapy. RESULTS: Median follow-up was 38.9 months, and age at diagnosis was 48 years.The 2-year and 5-year overall survival, progression-free survival, locoregional control, and disease metastasis-free survival rates were 94.1 and 84.7%, 88.2 and 73.5%, 93.8%, 94.1, and 78.4%, respectively. A total dose of 6600-7000 cGy was prescribed to the tumor. Levels Ⅰb, Ⅶa, Ⅷ, and Ⅸ were covered with the clinical target volume regardless of lymph involvement. Acute Grade 3 radiation dermatitis occurred in seven patients (17.6%), but no acute Grade 4 or Grade 5 toxicity of any type occurred. Seven (41.2%, 7/17) of the treated eyes had moderated vision impairments; 17.6% (3/17) of patients developed cataracts, and glaucoma and radiation retinopathy were found in 5.9% (1/17) of patients. CONCLUSIONS: Definitive radiotherapy could be a treatment option for those who refuse surgery or have unresectable LSSCC. ADVANCES IN KNOWLEDGE: Radiation alone is a treatment option for LSSCC.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Oculares/radioterapia , Ducto Nasolacrimal , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/mortalidade , Catarata/etiologia , Quimiorradioterapia/métodos , Intervalo Livre de Doença , Neoplasias Oculares/tratamento farmacológico , Neoplasias Oculares/mortalidade , Feminino , Glaucoma/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Lesões por Radiação/complicações , Radiodermatite/etiologia , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Estudos Retrospectivos , Resultado do Tratamento , Transtornos da Visão/etiologia , Adulto Jovem
6.
J Cancer Res Ther ; 16(3): 530-533, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719262

RESUMO

Context: An objective conformal radiotherapy treatment planning criteria that can predict severity of early effects of radiotherapy would be quite useful in reducing the side effects of radiotherapy thereby improving quality of life for head and neck cancer patients. Aim of Study: Retrospective study aimed at correlating the maximum dose in planning target volume (PTV) with early effects of radiation. Materials and Methods: Patients with squamous cell carcinoma of H and N region who received radical radiotherapy and concomitant chemotherapy were retrospectively analyzed for maximum dose in PTV and the requirement of gap during radiotherapy or else hospitalization for supportive care during or up to 1 month after completion of radical radiotherapy. Results: Of a total of 23 patients, 8 patients (34.7%) required a gap of 2-14 days during their treatment. Twelve patients (52.1%) required hospitalization for 1-4 days and 4 patients (17.3%) required hospitalization for supportive care after completion of radiotherapy. The maximum dose in PTV ranged from 105.1% to 132.8% with an average of 112.68%. Subgroup analysis revealed a nonsignificant highest maximum dose of 114.72% in subset of patients requiring gap during radiotherapy (n= 8). Conclusion: It was concluded that maximum dose in PTV is a useful predictor of need for inhospital supportive care.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Determinação de Necessidades de Cuidados de Saúde/estatística & dados numéricos , Cuidados Paliativos/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Segurança do Paciente , Qualidade de Vida , Dosagem Radioterapêutica , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Resultado do Tratamento
7.
J Cancer Res Ther ; 16(3): 594-599, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719273

RESUMO

Introduction: Radiation therapy is commonly used in the treatment of head and neck cancer in both the definitive and postoperative settings. Proton therapy, due to its intrinsic physical properties, has the ability to reduce the integral dose delivered to the patients while maintaining highly conformal target coverage. Materials and Methods: .A literature search was performed on scientific databases, and Preferred Reporting Items for Meta-Analyses guidelines were followed to compute results. Only original studies were selected. Selected studies were used to extract some proposed data for comparison, dosimetry, site, complications, and survival. Results: Proton beam therapy technology can be used against the conventional radiotherapy and shows satisfactory results. Yet conventional therapy is not less advantageous considering the amount of work available for any cross interpretations. Conclusion: Comparative preplanning could be beneficial considering multiple therapies for ruling out the best treatment outcomes that could be expected.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias de Cabeça e Pescoço/patologia , Implementação de Plano de Saúde , Humanos , Radiometria/métodos , Dosagem Radioterapêutica , Resultado do Tratamento
8.
Phys Med Biol ; 65(16): 165010, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575096

RESUMO

Recent changes to the guidelines for screening and early diagnosis of lung cancer have increased the interest in preserving post-radiotherapy lung function. Current investigational approaches are based on spatially mapping functional regions and generating regional avoidance plans that preferentially spare highly ventilated/perfused lung. A potentially critical, yet overlooked, aspect of functional avoidance is radiation injury to peripheral airways, which serve as gas conduits to and from functional lung regions. Dose redistribution based solely on regional function may cause irreparable damage to the 'supply chain'. To address this deficiency, we propose the functionally weighted airway sparing (FWAS) method. FWAS (i) maps the bronchial pathways to each functional sub-lobar lung volume; (ii) assigns a weighting factor to each airway based on the relative contribution of the sub-volume to overall lung function; and (iii) creates a treatment plan that aims to preserve these functional pathways. To evaluate it, we used four cases from a retrospective cohort of SAbR patients treated for lung cancer. Each patient's airways were auto-segmented from a diagnostic-quality breath-hold CT using a research virtual bronchoscopy software. A ventilation map was generated from the planning 4DCT to map regional lung function. For each terminal airway, as resolved by the segmentation software, the total ventilation within the sub-lobar volume supported by that airway was estimated and used as a function-based weighting factor. Upstream airways were weighted based on the cumulative volumetric ventilation supported by corresponding downstream airways. Using a previously developed model for airway radiosensitivity, dose constraints were determined for each airway corresponding to a <5% probability of airway collapse. Airway dose constraints, ventilation scores, and clinical dose constraints were input to a swarm optimization-based inverse planning engine to create a 3D conformal SAbR plan (CRT). The FWAS plans were compared to the patients' prescribed CRT clinical plans and the inverse-optimized clinical plans. Depending on the size and location of the tumour, the FWAS plan showed superior preservation of ventilation due to airflow preservation through open pathways (i.e. cumulative ventilation score from the sub-lobar volumes of open pathways). Improvements ranged between 3% and 23%, when comparing to the prescribed clinical plans, and between 3% and 35%, when comparing to the inverse-optimized clinical plans. The three plans satisfied clinical requirements for PTV coverage and OAR dose constraints. These initial results suggest that by sparing pathways to high-functioning lung subregions it is possible to reduce post-SAbR loss of respiratory function.


Assuntos
Neoplasias Pulmonares/radioterapia , Pulmão/fisiopatologia , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/efeitos da radiação , Ventilação Pulmonar/fisiologia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Idoso , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Respiração , Estudos Retrospectivos
9.
Vet Radiol Ultrasound ; 61(4): 481-489, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32356907

RESUMO

Radiotherapy with or without surgery is a common choice for brain tumors in dogs. Although numerous studies have evaluated use of three-dimensional conformal radiotherapy, reports of definitive-intent, IMRT for canine intracranial tumors are lacking. Intensity-modulated radiation therapy has the benefit of decreasing dose to nearby organs at risk and may aid in reducing toxicity. However, increasing dose conformity with IMRT calls for accurate target delineation and daily patient positioning, in order to decrease the risk of a geographic miss. To determine survival outcome and toxicity, we performed a multi-institutional retrospective observational study evaluating dogs with brain tumors treated with IMRT. Fifty-two dogs treated with fractionated, definitive-intent IMRT at four academic radiotherapy facilities were included. All dogs presented with neurologic signs and were diagnosed via MRI. Presumed radiological diagnoses included 37 meningiomas, 12 gliomas, and one peripheral nerve sheath tumor. One dog had two presumed meningiomas and one dog had either a glioma or meningioma. All dogs were treated in the macroscopic disease setting and were prescribed a total dose of 45-50 Gy (2.25-2.5 Gy per fraction in 18-20 daily fractions). Median survival time for all patients, including seven cases treated with a second course of therapy was 18.1 months (95% confidence of interval 12.3-26.6 months). As previously described for brain tumors, increasing severity of neurologic signs at diagnosis was associated with a worse outcome. Intensity-modulated radiation therapy was well tolerated with few reported acute, acute delayed, or late side effects.


Assuntos
Neoplasias Encefálicas/veterinária , Doenças do Cão/radioterapia , Neoplasias Meníngeas/veterinária , Radioterapia Conformacional/veterinária , Radioterapia de Intensidade Modulada/veterinária , Animais , Neoplasias Encefálicas/radioterapia , Cães , Feminino , Masculino , Neoplasias Meníngeas/radioterapia , Meningioma/radioterapia , Meningioma/veterinária , Dosagem Radioterapêutica/veterinária , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/veterinária , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
10.
Br J Radiol ; 93(1110): 20190692, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32293191

RESUMO

OBJECTIVE: The internal target volume (ITV) strategy generates larger planning target volumes (PTVs) in locally advanced non-small cell lung cancer (LA-NSCLC) than the Mid-position (Mid-p) strategy. We investigated the benefit of the Mid-p strategy regarding PTV reduction and dose to the organs at risk (OARs). METHODS: 44 patients with LA-NSCLC were included in a randomized clinical study to compare ITV and Mid-p strategies. GTV were delineated by a physician on maximum intensity projection images and on Mid-p images from four-dimensional CTs. CTVs were obtained by adding 6 mm uniform margin for microscopic extension. CTV to PTV margins were calculated using the van Herk's recipe for setup and delineation errors. For the Mid-p strategy, the mean target motion amplitude was added as a random error. For both strategies, three-dimensional conformal plans delivering 60-66 Gy to PTV were performed. PTVs, dose-volume parameters for OARs (lung, esophagus, heart, spinal cord) were reported and compared. RESULTS: With the Mid-p strategy, the median of volume reduction was 23.5 cm3 (p = 0.012) and 8.8 cm3 (p = 0.0083) for PTVT and PTVN respectively; the median mean lung dose reduction was 0.51 Gy (p = 0.0057). For 37.1% of the patients, delineation errors led to smaller PTV with the ITV strategy than with the Mid-p strategy. CONCLUSION: PTV and mean lung dose were significantly reduced using the Mid-p strategy. Delineation uncertainty can unfavorably impact the advantage. ADVANCES IN KNOWLEDGE: To the best of our knowledge, this is the first dosimetric comparison study between ITV and Mid-p strategies for LA-NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Movimentos dos Órgãos , Respiração , Idoso , Plexo Braquial/diagnóstico por imagem , Plexo Braquial/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Esôfago/diagnóstico por imagem , Esôfago/efeitos da radiação , Tomografia Computadorizada Quadridimensional , Coração/diagnóstico por imagem , Coração/efeitos da radiação , Humanos , Pulmão/diagnóstico por imagem , Pulmão/efeitos da radiação , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Órgãos em Risco/diagnóstico por imagem , Órgãos em Risco/efeitos da radiação , Estudos Prospectivos , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia Conformacional/métodos , Medula Espinal/diagnóstico por imagem , Medula Espinal/efeitos da radiação , Carga Tumoral
11.
In Vivo ; 34(2): 623-629, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32111762

RESUMO

BACKGROUND/AIM: Intensity modulated radiotherapy (IMRT) has been compared with three-dimensional conformal radiotherapy (3D-CRT) in randomized clinical trials for head and neck squamous cell carcinoma (HNSCC). The aim of this meta-analysis was to evaluate the efficacy and toxicity of IMRT and 3D-CRT and identify differences in grade ≥2 xerostomia incidence and clinical outcomes. MATERIALS AND METHODS: The preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement was applied. Random-effects models were used. Primary endpoint was xerostomia of grade 2 or worse. Secondary endpoints were overall survival (OS) and loco-regional control (LRC). RESULTS: Three randomized clinical trials representing 213 patients were identified. Global, grade ≥2 acute xerostomia and late xerostomia at 1 and 2 years after treatment were reduced with the IMRT technique (RR=0.71, 95%CI=0.59-0.86, RR=0.45, 95%CI=0.31-0.65 and RR=0.26, 95%CI=0.15-0.46, respectively). IMRT was not associated with significant OS and LRC improvement compared with 3D-CRT, with OR of 0.70 (95%CI=0.39-1.24; p=0.22) and 1.50 (95%CI=0.75-2.98; p=0.25). CONCLUSION: This meta-analysis explored the value of IMRT compared to 3D-CRT and confirmed the superiority of IMRT over 3D-CRT in terms of grade ≥2 xerostomia rates, but not on clinical outcomes. Its positive impact on tumor control and survival remains to be proven.


Assuntos
Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , Xerostomia/radioterapia , Feminino , Humanos , Masculino , Razão de Chances , Prognóstico , Dosagem Radioterapêutica , Radioterapia Conformacional/efeitos adversos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Resultado do Tratamento , Xerostomia/diagnóstico , Xerostomia/mortalidade
12.
Phys Med Biol ; 65(9): 095003, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32143198

RESUMO

Previous work has shown that PRESAGE® can be used successfully to perform 3D dosimetric measurements of complex radiotherapy treatments. However, measurements near the sample edges are known to be difficult to achieve. This is an issue when the doses at air-material interfaces are of interest, for example when investigating the electron return effect (ERE) present in treatments delivered by magnetic resonance (MR)-linac systems. To study this effect, a set of 3.5 cm-diameter cylindrical PRESAGE® samples was uniformly irradiated with multiple dose fractions, using either a conventional linac or an MR-linac. The samples were imaged between fractions using an optical-CT, to read out the corresponding accumulated doses. A calibration between TPS-predicted dose and optical-CT pixel value was determined for individual dosimeters as a function of radial distance from the axis of rotation. This data was used to develop a correction that was applied to four additional samples of PRESAGE® of the same formulation, irradiated with 3D-CRT and IMRT treatment plans, to recover significantly improved 3D measurements of dose. An alternative strategy was also tested, in which the outer surface of the sample was physically removed prior to irradiation. Results show that for the formulation studied here, PRESAGE® samples have a central region that responds uniformly and an edge region of 6-7 mm where there is gradual increase in dosimeter response, rising to an over-response of 24%-36% at the outer boundary. This non-uniform dose response increases in both extent and magnitude over time. Both mitigation strategies investigated were successful. In our four exemplar studies, we show how discrepancies at edges are reduced from 13%-37% of the maximum dose to between 2 and 8%. Quantitative analysis shows that the 3D gamma passing rates rise from 90.4, 69.3, 63.7 and 43.6% to 97.3, 99.9, 96.7 and 98.9% respectively.


Assuntos
Imageamento Tridimensional/instrumentação , Neoplasias Pulmonares/radioterapia , Aceleradores de Partículas/instrumentação , Imagens de Fantasmas , Radiometria/instrumentação , Planejamento da Radioterapia Assistida por Computador/métodos , Calibragem , Raios gama , Humanos , Imageamento Tridimensional/métodos , Radiometria/métodos , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos
13.
Cancer Radiother ; 24(2): 159-165, 2020 Apr.
Artigo em Francês | MEDLINE | ID: mdl-32151544

RESUMO

Ovarian cancer is the fifth most common cancer in women in France with 4714 new cases in 2017. More than 70% of patients whose disease is initially locally advanced will present locoregional or distant recurrence. Therapeutic options in this situation are not consensual. They are based on chemotherapy possibly associated with an iterative cytoreductive surgery when it is bearable by the patient. The place of radiotherapy in the management of the disease is hidden in the vast majority of national or international standards. We conducted a general review of the literature to clarify the role of irradiation in the global management of ovarian cancers, particularly in recurrence.


Assuntos
Recidiva Local de Neoplasia/radioterapia , Neoplasias Ovarianas/radioterapia , Antineoplásicos/uso terapêutico , Feminino , Humanos , Recidiva Local de Neoplasia/classificação , Neoplasias Ovarianas/classificação , Cuidados Paliativos/métodos , Radiocirurgia/métodos , Radioterapia Adjuvante , Radioterapia Conformacional/métodos
14.
BMC Cancer ; 20(1): 90, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32013912

RESUMO

BACKGROUND: It has been hypothesized that radiotherapy (RT) techniques delivering radiations to larger volumes (IMRT, VMAT) are potentially associated with a higher risk of second primary tumors. The aim of this study was to analyse the impact of RT technique (3D-CRT vs IMRT/VMAT) on the incidence of second tumors in prostate cancer (PCa) patients. METHODS: A retrospective study on 2526 previously irradiated PCa patients was performed. Patients were treated with 3D-CRT (21.3%), IMRT (68.1%), or VMAT (10.6%). Second tumors incidence was analysed in 3 categories: pelvic, pelvic and abdominal, and "any site". The correlation with RT technique was analysed using log-rank test and Cox's proportional hazard method. RESULTS: With a median follow-up of 72 months (range: 9-185), 92 (3.6%) cases of second tumors were recorded with 48 months (range: 9-152) median interval from RT. Actuarial 10-year second tumor free survival (STFS) was 87.3%. Ten-year STFS in patients treated with 3D-CRT and IMRT/VMAT was 85.8 and 84.5%, respectively (p: .627). A significantly higher 10-year cumulative incidence of second tumors in the pelvis was registered in patients treated with IMRT/VMAT compared to 3D-CRT (10.7% vs 6.0%; p: .033). The lower incidence of second pelvic cancers in patients treated with 3D-CRT was confirmed at multivariable analysis (HR: 2.42, 95%CI: 1.07-5.47, p: .034). CONCLUSIONS: The incidence of second pelvic tumors after RT of PCa showed a significant correlation with treatment technique. Further analyses in larger series with prolonged follow-up are needed to confirm these results.


Assuntos
Segunda Neoplasia Primária/epidemiologia , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/etiologia , Modelos de Riscos Proporcionais , Radioterapia Conformacional/efeitos adversos , Radioterapia de Intensidade Modulada , Estudos Retrospectivos , Resultado do Tratamento
15.
Int J Radiat Oncol Biol Phys ; 106(3): 604-611, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32014151

RESUMO

PURPOSE: Steep dose falloff outside of tumors is a hallmark of stereotactic radiosurgery (SRS) and radiation therapy (SRT). Dose gradient index (DGI) quantifies the dose drop off. Tables of DGIs versus target volumes have been published for body sites, but none is available for brain. This study recommends guidelines for DGIs for brain SRS/SRT treatments based on clinical CyberKnife (CK) cases. METHODS AND MATERIALS: Four hundred ninety-five plans for patients with central nervous system tumors treated with CK at our institution between March 2015 and May 2018 were analyzed. The CK treatment planning system MultiPlan was used for planning. SRS/SRT plans were stratified into 6 groups by tumor size (Group I [0-1 cm3], II [1.0-3.0 cm3], III [3.0-5.0 cm3], IV [5.0-10.0 cm3], V [10.0-15.0 cm3], and VI [15.0-40.0 cm3]). Ideal and minimally acceptable DGIs were determined for each size group. To evaluate the effect of target shape on DGI criteria, the plans were divided into 4 target shape groups: (1) homogeneous shape (circular), (2) adjacent to radiosensitive organs at risk (adjacent), (3) irregularly shaped (irregular), and (4) multiple target plans (multilesion). The mean for each target size group was defined as the ideal DGI. Minimally acceptable DGI criteria are specified to reject the lowest 10% of cases. RESULTS: The minimal acceptable DGIs were 83 (Group I), 72 (II), 65 (III), 58 (IV), 52 (V), and 35 (VI). The ideal DGI is designated to evaluate SRS/SRT plans for homogeneous circular lesions, whereas minimal DGI is chosen to assess the plans for irregular, adjacent to organs at risk, and multilesions. SRS/SRT plans with higher DGI values are correlated with lower irradiated normal tissue volumes. CONCLUSIONS: This study provides a table of DGIs for brain SRS/SRT treatments as a tool for assessing the quality of intracranial SRS/SRT plans. DGI guidelines support SRS/SRT planning that results in lower risk of radionecrosis.


Assuntos
Neoplasias Encefálicas/radioterapia , Órgãos em Risco/efeitos da radiação , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Guias como Assunto , Humanos , Órgãos em Risco/diagnóstico por imagem , Tolerância a Radiação , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Radioterapia Conformacional/efeitos adversos , Espalhamento de Radiação
16.
Lancet Oncol ; 21(2): e74-e82, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32007208

RESUMO

MRI-guided radiotherapy is a novel and rapidly evolving technology that might enhance the risk-benefit ratio. Through direct visualisation of the tumour and the nearby healthy tissues, the radiation oncologist can deliver highly accurate treatment even to mobile targets. Each individual treatment can be customised to changing anatomy, potentially reducing the risk of radiation-related toxicities while simultaneously increasing the dose delivered to the tumour. MRI-guided radiotherapy offers a new tool for the radiation oncologist, and creates an opportunity to achieve durable local control of liver tumours that might not otherwise be possible. Future work will allow us to expand the population eligible for curative-intent radiotherapy, optimise and customise radiation doses to specific tumours, and hopefully create opportunities for improving outcomes through machine learning and radiomics-based approaches. This Review outlines the current and future applications for MRI-guided radiotherapy with respect to metastatic and primary liver cancers.


Assuntos
Neoplasias Hepáticas/radioterapia , Imagem por Ressonância Magnética/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia Guiada por Imagem/métodos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Dosagem Radioterapêutica
17.
Jpn J Clin Oncol ; 50(3): 303-309, 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-31926489

RESUMO

OBJECTIVES: We aimed to compare the dose constraints fulfillment rate of the three-dimensional conformal radiotherapy treatment plan before and after a hydrogel spacer insertion. METHODS: The planning computed tomography scans of 39 patients who received stereotactic body radiotherapy for prostate cancer were used. All patients inserted a hydrogel spacer and underwent computed tomography scans before and after spacer insertion. The three-dimensional conformal radiotherapy plans according to NCCN classification, low-, intermediate- and high-risk, were made for each patient. Clinical target volume included prostate and seminal vesicle 2 cm for high risk, prostate and seminal vesicle 1 cm for intermediate risk and prostate only for low risk. Three-dimensional conformal radiotherapy including a seven-field conformal technique with 76 Gy in 38 fractions. Dose constraints for rectum and bladder were V70 Gy ≤ 15%, V65 Gy ≤ 30% and V40 Gy ≤ 60%. RESULTS: Among 39 patients, 35 (90%), 19 (49%) and 13 (33%) and 38 (97%), 38 (97%) and 34 (87%) patients before and after the spacer insertion fulfilled rectum dose constraints for low-, intermediate- and high-risk plans, respectively. A hydrogel spacer significantly reduced rectum dose and improved the rectum dose constraints fulfillment rate in intermediate (P < 0.01) and high (P < 0.01), but no difference was found in low-risk plan (P = 0.25). On multivariate analysis, spacer use was associated with the higher rectum dose constraints fulfillment rate. CONCLUSIONS: A hydrogel spacer reduced rectum dose and improved the dose constraints fulfillment rate in three-dimensional conformal radiotherapy plan. Although IMRT is the standard treatment, 3D-CRT using a hydrogel spacer may be a treatment option.


Assuntos
Equipamentos e Provisões , Hidrogéis , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/instrumentação , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Reto , Tomografia Computadorizada por Raios X
18.
Strahlenther Onkol ; 196(2): 182-192, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31925465

RESUMO

PURPOSE: Intra- and inter-fraction organ motion is a major concern in stereotactic body radiation therapy (SBRT). It may cause substantial differences between the planned and delivered dose distribution. Such delivery errors may lead to medical harm and reduce life expectancy for patients. The project presented here investigates and improves a rapid method to detect such errors by performing online dose verification through the analysis of electronic portal imaging device (EPID) images. METHODS: To validate the method, a respiratory phantom with inhomogeneous insert was examined under various scenarios: no-error and error-simulated measurements. Simulation of respiratory motions was practiced for target ranges up to 2 cm. Three types of treatment planning technique - 3DCRT (three-dimensional conformal radiation therapy), IMRT (intensity modulated radiation therapy), and VMAT (volumetric modulated arc therapy - were generated for lung SBRT. A total of 54 plans were generated to assess the influence of techniques on the performance of portal dose images. Subsequently, EPID images of 52 SBRT patients were verified. Both for phantom and patient cases, dose distributions were compared using the gamma index method according to analysis protocols in the target volume. RESULTS: The comparison of error-introduced EPID-measured images to reference images showed no significant differences with 3%/3 mm gamma evaluation, though target coverage was strongly underestimated. Gamma tolerance of 2%/2 mm reported noticeable detection in EPID sensitivity for simulated errors in 3DCRT and IMRT techniques. The passing rates for 3DCRT, IMRT, and VMAT with 1%/1 mm in open field were 84.86%, 92.91%, and 98.75%, and by considering MLC-CIAO + 1 cm (threshold 5%), were 68.25%, 83.19%, and 95.29%, respectively. CONCLUSION: This study demonstrates the feasibility of EPID for detecting the interplay effects. We recommend using thin computed tomography slices and adding sufficient tumor margin in order to limit the dosimetric organ motion in hypofractionated irradiation with preserved plan quality. In the presence of respiratory and gastrointestinal motion, tighter criteria and consequently using local gamma evaluation should be considered, especially for VMAT. This methodology offers a substantial step forward in in vivo dosimetry and the potential to distinguish errors depending on the gamma tolerances. Thus, the approach/prototype provides a fast and easy quality assurance procedure for treatment delivery verification.


Assuntos
Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Garantia da Qualidade dos Cuidados de Saúde , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X , Carga Tumoral/efeitos da radiação , Adulto Jovem
19.
Strahlenther Onkol ; 196(4): 356-367, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31980834

RESUMO

PURPOSE: Radiochemotherapy is the standard treatment for anal carcinoma (ACa). Intensity-modulated radiotherapy (IMRT) has been introduced, allowing focused irradiation of the tumor area. Whether physical benefits of IMRT translate to clinical benefits has not been sufficiently demonstrated. METHODS: We retrospectively reviewed data from 82 patients with newly diagnosed ACa. Patients treated with IMRT were compared with previous patients treated with conventional three-dimensional computational radiotherapy (3D-CRT). The influence of IMRT on complete remission and acute and chronic side effects was analyzed in univariate and multivariate analyses. RESULTS: 39/40 patients treated with IMRT were in complete remission after 1 year compared to 31/39 patients treated with 3D-CRT (p = 0.014). Multivariate analysis confirmed tumor T stage as well as lack of IMRT treatment as risk factors for persistent tumor at 6 months. No significant benefits of IMRT were apparent at later timepoints (median follow up 52 months, IQR: 31.5-71.8 months). Patients treated with IMRT had a significantly lower degree of skin toxicity (median 2 vs. 3 in a scale ranging from 0 to 3, p = 0.00092). Rates of hematological toxicity/proctitis were not reduced and rates of acute diarrhea increased (p = 0.034). Median length of hospitalization tended to be shorter in patients treated with IMRT (n. s.). CONCLUSION: We present a real-world experience of shifting radiation technique from conventional 3D-CRT to IMRT. IMRT patients had better tumor control at 1 year and lower degrees of skin toxicity. Our data indicate that IMRT can enable therapies with lower side effects with equal or better oncological results for patients with ACa.


Assuntos
Neoplasias do Ânus/radioterapia , Radiodermatite/prevenção & controle , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Ânus/tratamento farmacológico , Neoplasias do Ânus/patologia , Quimioterapia Adjuvante , Terapia Combinada , Feminino , Fluoruracila/uso terapêutico , Humanos , Infusões Intravenosas , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Lesões por Radiação/etiologia , Radioterapia Conformacional/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos , Indução de Remissão , Estudos Retrospectivos , Resultado do Tratamento
20.
Br J Radiol ; 93(1107): 20190879, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31804145

RESUMO

OBJECTIVE: Locally recurrent disease is of increasing concern in (non-)small cell lung cancer [(N)SCLC] patients. Local reirradiation with photons or particles may be of benefit to these patients. In this multicentre in silico trial performed within the Radiation Oncology Collaborative Comparison (ROCOCO) consortium, the doses to the target volumes and organs at risk (OARs) were compared when using several photon and proton techniques in patients with recurrent localised lung cancer scheduled to undergo reirradiation. METHODS: 24 consecutive patients with a second primary (N)SCLC or recurrent disease after curative-intent, standard fractionated radio(chemo)therapy were included in this study. The target volumes and OARs were centrally contoured and distributed to the participating ROCOCO sites. Remaining doses to the OARs were calculated on an individual patient's basis. Treatment planning was performed by the participating site using the clinical treatment planning system and associated beam characteristics. RESULTS: Treatment plans for all modalities (five photon and two proton plans per patient) were available for 22 patients (N = 154 plans). 3D-conformal photon therapy and double-scattered proton therapy delivered significantly lower doses to the target volumes. The highly conformal techniques, i.e., intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), CyberKnife, TomoTherapy and intensity-modulated proton therapy (IMPT), reached the highest doses in the target volumes. Of these, IMPT was able to statistically significantly decrease the radiation doses to the OARs. CONCLUSION: Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. They, however, significantly differ in the dose deposited in the OARs. The therapeutic options, i.e., reirradiation or systemic therapy, need to be carefully weighed and discussed with the patients. ADVANCES IN KNOWLEDGE: Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. In light of the abilities of the various highly conformal techniques to spare specific OARs, the therapeutic options need to be carefully weighed and patients included in the decision-making process.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Recidiva Local de Neoplasia/radioterapia , Órgãos em Risco/efeitos da radiação , Fótons/uso terapêutico , Terapia com Prótons/métodos , Reirradiação/métodos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Conjuntos de Dados como Assunto , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Órgãos em Risco/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Resultado do Tratamento
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