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1.
Medicine (Baltimore) ; 100(20): e26000, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34011096

RESUMO

BACKGROUND: This meta-analysis evaluates the difference of sparing organs at risk (OAR) in different position (Prone position and Supine position) with different breathing patterns (Free breathing, FB/Deep inspiration breath hold, DIBH) for breast cancer patients receiving postoperative radiotherapy and provides a useful reference for clinical practice. METHOD: The relevant controlled trials of prone position versus supine position in postoperative radiotherapy for breast cancer were retrieved from the sources of PubMed, Cochrane Library, Embase, Web of Science and ClinicalTrails.gov. The principal outcome of interest was OAR doses (heart dose, left anterior descending coronary artery dose and ipsilateral lung dose) and target coverage. We mainly compared the effects of P-FB (Prone position FB) and S-FB (Supine position FB) and discussed the effects of DIBH combined with different positions on OAR dose in postoperative radiotherapy. We calculated summary standardized mean difference (SMD) and 95% confidence intervals (CI). The meta-analysis was performed using RevMan 5.4 software. RESULTS: The analysis included 751 patients from 19 observational studies. Compared with the S-FB, the P-FB can have lower heart dose, left anterior descending coronary artery (LADCA) dose, and ipsilateral lung dose (ILL) more effectively, and the difference was statistically significant (heart dose, SMD = - 0.51, 95% CI - 0.66 ∼ - 0.36, P < .00001. LADCA dose, SMD = - 0.58, 95% CI - 0.85 ∼ - 0.31, P < .0001. ILL dose, SMD = - 2.84, 95% CI - 3.2 ∼ - 2.48, P < .00001). And there was no significant difference in target coverage between the S-FB and P-FB groups (SMD = - 0.1, 95% CI - 0.57 ∼ 0.36, P = .66). Moreover, through descriptive analysis, we found that P-DIBH (Prone position DIBH) has better sparing OAR than P-FB and S-DIBH (Supine position DIBH). CONCLUSION: By this meta-analysis, compared with the S-FB we found that implementation of P-FB in postoperative radiotherapy for breast cancer can reduce irradiation of heart dose, LADCA dose and ILL dose, without compromising mean dose of target coverage. Moreover, P-DIBH might become the most promising way for breast cancer patients to undergo radiotherapy.


Assuntos
Neoplasias da Mama/terapia , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/efeitos da radiação , Posicionamento do Paciente/métodos , Lesões por Radiação/prevenção & controle , Vasos Coronários/efeitos da radiação , Feminino , Coração/efeitos da radiação , Humanos , Pulmão/efeitos da radiação , Mastectomia , Decúbito Ventral , Lesões por Radiação/etiologia , Radiometria/estatística & dados numéricos , Dosagem Radioterapêutica , Radioterapia Adjuvante/efeitos adversos , Radioterapia Adjuvante/métodos , Decúbito Dorsal
2.
Cancer Imaging ; 21(1): 31, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827699

RESUMO

BACKGROUND: Many studies have successfully identified radiomics features reflecting macroscale tumor features and tumor microenvironment for various organs. There is an increased interest in applying these radiomics features found in a given organ to other organs. Here, we explored whether common radiomics features could be identified over target organs in vastly different environments. METHODS: Four datasets of three organs were analyzed. One radiomics model was constructed from the training set (lungs, n = 401), and was further evaluated in three independent test sets spanning three organs (lungs, n = 59; kidneys, n = 48; and brains, n = 43). Intensity histograms derived from the whole organ were compared to establish organ-level differences. We constructed a radiomics score based on selected features using training lung data over the tumor region. A total of 143 features were computed for each tumor. We adopted a feature selection approach that favored stable features, which can also capture survival. The radiomics score was applied to three independent test data from lung, kidney, and brain tumors, and whether the score could be used to separate high- and low-risk groups, was evaluated. RESULTS: Each organ showed a distinct pattern in the histogram and the derived parameters (mean and median) at the organ-level. The radiomics score trained from the lung data of the tumor region included seven features, and the score was only effective in stratifying survival for other lung data, not in other organs such as the kidney and brain. Eliminating the lung-specific feature (2.5 percentile) from the radiomics score led to similar results. There were no common features between training and test sets, but a common category of features (texture category) was identified. CONCLUSION: Although the possibility of a generally applicable model cannot be excluded, we suggest that radiomics score models for survival were mostly specific for a given organ; applying them to other organs would require careful consideration of organ-specific properties.


Assuntos
Órgãos em Risco/efeitos da radiação , Radiometria/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Phys Med Biol ; 66(3): 035023, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33522498

RESUMO

The aim of this study was to evaluate the clinical impact of relative biological effectiveness (RBE) variations in proton beam scanning treatment (PBS) for left-sided breast cancer versus the assumption of a fixed RBE of 1.1, particularly in the context of comparisons with photon-based three-dimensional conformal radiotherapy (3DCRT) and volumetric modulated arc therapy (VMAT). Ten patients receiving radiation treatment to the whole breast/chest wall and regional lymph nodes were selected for each modality. For PBS, the dose distributions were re-calculated with both a fixed RBE and a variable RBE using an empirical RBE model. Dosimetric indices based on dose-volume histogram analysis were calculated for the entire heart wall, left anterior descending artery (LAD) and left lung. Furthermore, normal tissue toxicity probabilities for different endpoints were evaluated. The results show that applying a variable RBE significantly increases the RBE-weighted dose and consequently the calculated dosimetric indices increases for all organs compared to a fixed RBE. The mean dose to the heart and the maximum dose to the LAD and the left lung are significantly lower for PBS assuming a fixed RBE compared to 3DCRT. However, no statistically significant difference is seen when a variable RBE is applied. For a fixed RBE, lung toxicities are significantly lower compared to 3DCRT but when applying a variable RBE, no statistically significant differences are noted. A disadvantage is seen for VMAT over both PBS and 3DCRT. One-to-one plan comparison on 8 patients between PBS and 3DCRT shows similar results. We conclude that dosimetric analysis for all organs and toxicity estimation for the left lung might be underestimated when applying a fixed RBE for protons. Potential RBE variations should therefore be considered as uncertainty bands in outcome analysis.


Assuntos
Coração/efeitos da radiação , Pulmão/efeitos da radiação , Órgãos em Risco/efeitos da radiação , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Neoplasias Unilaterais da Mama/radioterapia , Feminino , Humanos , Eficiência Biológica Relativa
4.
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
5.
Cancer Radiother ; 25(3): 254-258, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33402289

RESUMO

PURPOSE: The use of IMRT for the treatment of breast cancer has been growing considerably in our institution since 2009. Alternatively, helical tomotherapy (HT) using a field width of 2.5 and 5cm (HT_FW_5), volumetric-modulated arc therapy (VMAT), or proton therapy with pencil-beam scanning (PT-PBS) have also been used to reduce treatment duration or optimize organ-at-risk (OAR) sparing. The purpose of this study was to compare the 4 treatment modalities available at our site. PATIENTS AND METHODS: We studied 10 patients treated for breast cancer with lymph node involvement. The prescribed dose was 51.8Gy to the breast with a simultaneous integrated boost up to 63Gy, and 50.4Gy to lymph nodes in 28 fractions. The CTV was delineated according to ESTRO Guidelines. Dosimetric planning in routine clinical practice was performed using HT_FW_2.5. The approved clinical plan was compared to the 3 other plans. Dosimetric goals for PTV coverage were D95%≥95% and D2%≤107% of the prescribed dose. Mean and maximum doses to OAR were recorded. RESULTS: HT_FW_5 and VMAT plans ensure equivalent or even better PTV coverage compared to the initial clinically approved plan but at the cost of poorer OAR sparing. PT_PBS plans showed that an excellent PTV coverage can be maintained with significantly lower doses to OAR. CONCLUSION: HT_FW_5 and VMAT plans allow a significant reduction of treatment duration and can be a good alternative to HT_FW_2.5 for specific populations. HT_FW_2.5 could be chosen for patients at higher risk of side effects. In addition, PT_PBS should be considered in the near future as it has been shown to have a major potential benefit to lower the risk of side effects with the same level of PTV coverage.


Assuntos
Radioterapia de Intensidade Modulada/métodos , Neoplasias Unilaterais da Mama/radioterapia , Adulto , Mama/efeitos da radiação , Fracionamento da Dose de Radiação , Feminino , Coração/efeitos da radiação , Humanos , Pulmão/efeitos da radiação , Linfonodos/patologia , Irradiação Linfática , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Unilaterais da Mama/diagnóstico por imagem , Neoplasias Unilaterais da Mama/patologia
6.
Cancer Radiother ; 25(3): 271-278, 2021 May.
Artigo em Francês | MEDLINE | ID: mdl-33402293

RESUMO

PURPOSE: Radiation therapy (RT) for muscle invasive bladder cancer (MIBC) is challenging, with observed variations in bladder shape and size resulting in inappropriate coverage of the target volumes (CTV). Large margins were historically applied around the CTV, increasing the dose delivered to organs at risk (OAR). With repositioning imaging and visualization of soft tissues during image guided RT, an opportunity to consider these movements and deformations appeared possible with an adaptive RT approach (ART). MATERIALS AND METHODS: A bibliographic search on the PubMed database has been done in January 2019. Studies focusing on patients with MIBC, treating on ART, with the objectives of feasibility, clinical and/or dosimetric evaluation and comparison with a standard irradiation technique were eligible. The purpose of this review was to define the different ART techniques used in clinical practice, to discuss their advantages compared to conventional RT in terms of target volume's coverage and OAR dose and to describe their feasibility in clinical practice. RESULTS: A total of 30 studies were selected. The strategies known as "composite offline", "plan of the day" not individualized or individualized, and "re-optimization" have been identified. All the studies have shown a significant benefit of ART in target coverage and dose of OAR, especially the rectum and small bowel. All ART plans produced are not used during RT sessions. Inter-observer variability for the selection of these plans can be observed. The practical implementation within a department required staff education and training, and increases the duration of treatment preparation. The "A-POLO" approach seems to be the most suitable for practice. CONCLUSION: ART is the technique of choice for bladder cancer RT. The "plan of the day" approach, individualized according to the A-POLO methodology, seems to be the most effective. The emergence of daily re-optimization, especially using MRI-Linac, is promising. The correlation between dosimetric benefits and clinical efficacy and safety results should be demonstrated into future trials.


Assuntos
Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias da Bexiga Urinária/radioterapia , Estudos de Viabilidade , Humanos , Movimentos dos Órgãos , Órgãos em Risco/efeitos da radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias da Bexiga Urinária/patologia
7.
Cancer Radiother ; 25(3): 237-241, 2021 May.
Artigo em Francês | MEDLINE | ID: mdl-33419606

RESUMO

PURPOSE: Stereotactic body radiotherapy (SBRT) of prostate cancer is associated with rectal toxicities, which can be reduced by using a hydrogel spacer. The object of this retrospective study was to show the feasibility of spacer placement under local anesthesia and utility of hydrogel spacer to reduce the dose to the rectal wall. MATERIAL AND METHODS: We collected data from all patients with localised prostate cancer treated with SBRT (40Gy in 5 fractions) between 2018 and 2020. A hydrogel spacer (SpaceOAR®) was placed depending on the availability of the product. We collected dosimetric data for target volumes and organs at risk. We calculated mean values, which were compared using non-parametric tests. RESULTS: Among 35 patients, mean age was 75 years. Seventeen had a spacer placed, with a mean space created of 10mm. No complication was reported during the intervention. High doses to the rectal wall were significantly lower in spacer group (V38: 0.39 cm3 vs. 0.72 cm3; P=0.02). PTV were better covered in spacer group (P=0.07). Doses to the bladder wall were similar in both groups. CONCLUSION: Spacer procedure under local anesthesia was well tolerated. Hydrogel spacer allowed to reduce doses to the rectum while improving PTV coverage.


Assuntos
Hidrogéis/administração & dosagem , Neoplasias da Próstata/radioterapia , Lesões por Radiação/prevenção & controle , Radiocirurgia/métodos , Reto/efeitos da radiação , Idoso , Idoso de 80 Anos ou mais , Anestesia Local , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Neoplasias da Próstata/patologia , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Estudos Retrospectivos , Estatísticas não Paramétricas , Bexiga Urinária/efeitos da radiação
8.
Cancer Radiother ; 25(3): 229-236, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33423965

RESUMO

PURPOSE: This study aimed to assess radiation dose distribution to cardiac subvolumes in left-sided breast cancer radiotherapy (LBCRT) and to clarify whether the mean heart dose (MHD) reliably reflects cardiac substructures exposure. MATERIALS AND METHODS: Fifty women referred for adjuvant LBCRT were prospectively evaluated. All patients received 3D-conformal hypofractionated radiotherapy (40Gy delivered in 15 fractions of 2.67Gy±boost of 13.35Gy). Cardiac substructures were contoured using the F. Duane's cardiac atlas. Dose distribution to cardiac chambers, left main (LM), left anterior descending (LAD), left circumflex (LCx) and right coronary artery (RCA)) was assessed. Dosimetric associations were analysed. RESULTS: The mean MHD was 3.08Gy (EQD2=3.67Gy). The mean Dmean/Dmax LAD was 11.45Gy (EQD2=13.64Gy)/29.5Gy (EQD2=35.15Gy). Low doses were delivered to LM, LCx, and RCA (Dmean≤1.3Gy). The left ventricle (LV) was the most exposed cardiac chamber with Dmean/Dmax of 4.78Gy/37Gy. The strongest correlation with MHD was found for Dmean LAD (r=0.81). For every 1Gy increase in MHD, Dmean LAD rose by 3.4Gy. However, the proportion of variance in Dmean LAD predictable from MHD was moderate (R2=0.65). For all other cardiac substructures, R2 values were<0.7. CONCLUSION: Our study showed high exposure of LAD and LV in LBCRT. With poor predictive value, MHD may underestimate doses to cardiac substructures. For optimal heart sparing radiotherapy, we recommend to consider LV and LAD as separate organ at risk.


Assuntos
Cardiotoxicidade/etiologia , Coração/efeitos da radiação , Radioterapia Conformacional/efeitos adversos , Neoplasias Unilaterais da Mama/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/radioterapia , Carcinoma Lobular/tratamento farmacológico , Carcinoma Lobular/radioterapia , Vasos Coronários/efeitos da radiação , Feminino , Átrios do Coração/efeitos da radiação , Ventrículos do Coração/efeitos da radiação , Humanos , Irradiação Linfática , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Estudos Prospectivos , Doses de Radiação , Hipofracionamento da Dose de Radiação , Reirradiação , Neoplasias Unilaterais da Mama/tratamento farmacológico
9.
Vet Radiol Ultrasound ; 62(2): 246-254, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33460237

RESUMO

Planning organ at risk volume (PRV) estimates have been reported as methods for sparing organs at risk (OARs) during radiation therapy, especially for hypofractioned and/or dose-escalated protocols. The objectives of this retrospective, analytical, observational study were to evaluate peri-ocular OAR shifts and derive PRVs in a sample of dogs undergoing radiation therapy for periocular tumors. Inclusion criteria were as follows: dogs irradiated for periocular tumors, with 3D-image-guidance and at least four cone-beam CTs (CBCTs) used for position verification, and positioning in a rigid bite block immobilization device. Peri-ocular OARs were contoured on each CBCT and the systematic and random error of the shifts in relation to the planning CT position computed. The formula 1.3×Σ+0.5xσ was used to generate a PRV of each OAR in the dorsoventral, mediolateral, and craniocaudal axis. A total of 30 dogs were sampled, with 450 OARs contoured, and 2145 shifts assessed. The PRV expansion was qualitatively different for each organ (1-4 mm for the dorsoventral and 1-2 mm for the mediolateral and craniocaudal axes). Maximal PRV expansion was ≤4 mm and directional for the majority; most pronounced for corneas and retinas. Findings from the current study may help improve awareness of and minimization of radiation dose in peri-ocular OARs for future canine patients. Because some OARs were difficult to visualize on CBCTs and/ or to delineate on the planning CT, authors recommend that PRV estimates be institution-specific and applied with caution.


Assuntos
Tomografia Computadorizada de Feixe Cônico/veterinária , Imageamento Tridimensional/veterinária , Planejamento da Radioterapia Assistida por Computador/veterinária , Animais , Cães , Tamanho do Órgão , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Radioterapia Guiada por Imagem/veterinária , Estudos Retrospectivos
10.
Cancer Radiother ; 25(1): 77-91, 2021 Feb.
Artigo em Francês | MEDLINE | ID: mdl-33358082

RESUMO

Pelvic bone marrow is the site of nearly 50% of total hematopoiesis. Radiation therapy of pelvic lymph node areas, and cancers located near the bony structures of the pelvis, exposes to hematological toxicity in the range of 30 to 70%. This toxicity depends on many factors, including the presence or absence of concomitant chemotherapy and its type, the volume of irradiated bone, the received doses, or the initial hematopoietic reserve. Intensity modulated radiation therapy allows the optimisation of dose deposit on at risk organs while providing optimal coverage of target volumes. However, this suggests that dose constraints should be known precisely to limit the incidence of radiation side effects. This literature review focuses firstly on pelvic lymph node areas and bony volumes nearby, then on the effects of irradiation on bone marrow and the current dosimetric constraints resulting from it, and finally on hematological toxicities by carcinologic location and progress in reducing these toxicities.


Assuntos
Medula Óssea/efeitos da radiação , Quimiorradioterapia/efeitos adversos , Hematopoese/efeitos da radiação , Irradiação Linfática/efeitos adversos , Ossos Pélvicos/efeitos da radiação , Neoplasias Pélvicas/terapia , Neoplasias do Ânus/terapia , Quimiorradioterapia/métodos , Feminino , Neoplasias dos Genitais Femininos/terapia , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos da radiação , Órgãos em Risco/efeitos da radiação , Pelve , Neoplasias da Próstata/terapia , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Neoplasias Retais/terapia , Irradiação Corporal Total/efeitos adversos
11.
Br J Radiol ; 94(1119): 20200239, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33353402

RESUMO

OBJECTIVE: This study aimed to assess the dosimetric effect of intestinal gas of stereotactic magnetic resonance (MR)-guided adaptive radiation therapy (SMART) on target and critical organs for pancreatic cancer without online electron density correction (EDC). METHODS: Thirty pancreatic cancer patients who underwent online SMART were selected for this study. The treatment time of each stage and the total treatment time were recorded and analyzed. The concerned dose-volume parameters of target and organs-at-risk (OAR) were compared with and without an intestinal gas EDC using the Wilcoxon-signed rank test. Analysis items with p value < 0.05 were considered statistically significant. The relationships between dosimetric differences and intestinal gas volume variations were investigated using the Spearman test. RESULTS: The average treatment time was 82 min, and the average EDC time was 8 min, which accounted for 10% of the overall treatment time. There were no significant differences in CTV (GTV), PTV, bowel, stomach, duodenum, and skin (p > 0.05) with respect to dose volume parameters. For the Dmax of gastrointestinal organs (p = 0.03), the mean dose of the liver (p = 0.002) and kidneys (p = 0.03 and p = 0.04 for the left and right kidneys, respectively), there may be a risk of slight overestimation compared with EDC, and for the Dmax of the spinal cord (p = 0.02), there may be a risk of slight underestimation compared with EDC. A weak correlation for D95 in the PTV and D0.5 cc in the duodenum was observed. CONCLUSION: For patients with similar inter-fractional intestinal gas distribution, EDC had little dosimetric effects on the D0.5 cc of all GI organs and dose volume parameters of target in most plans. ADVANCES IN KNOWLEDGE: By omitting the EDC of intestinal gas, the online SMART treatment time can be shortened.


Assuntos
Imagem por Ressonância Magnética Intervencionista/métodos , Órgãos em Risco/efeitos da radiação , Neoplasias Pancreáticas/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Elétrons , Feminino , Humanos , Intestinos/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica
12.
Br J Radiol ; 94(1117): 20200848, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33095659

RESUMO

OBJECTIVE: The main aim of the current analysis was to explore the hypothetical advantages using rectal spacer during 1.5T MR-guided and daily adapted prostate cancer stereotactic body radiotherapy (SBRT) compared to a no-rectal spacer hydrogel cohort of patients. METHODS: The SBRT-protocol consisted of a 35 Gy schedule delivered in 5 fractions. Herein, we present a dosimetric analysis between spacer and no-spacer patients. Furthermore, treatment tolerability and feasibility were preliminarily assessed according to clinicians-reported outcomes at the end of treatment and patient-reported outcomes measures (PROMs) in both arms. Toxicity and quality of life were assessed at baseline and after treatment using the Common Terminology Criteria for Adverse Events v. 5.0, International Prostatic Symptoms Score, ICIQ-SF, IIEF-5, and EORTC-QLQ-C30 and PR-25 questionnaires. RESULTS: 120 plans (pre- and daily adaptive SBRT planning) were analyzed in 20 patients (10 patients in spacer group and 10 patients in no-spacer group) treated using 1.5T MR-guided adaptive SBRT. Statistically significant dosimetric advantages were observed in favor of the spacer insertion, improving the planning target volume coverage in terms of V33.2Gy >95% and planning target volume 37.5 Gy <2% mainly during daily-adapted SBRT. Also, rectum V32, V28 and V18Gy and bladder V35Gy <1 cc were significantly reduced in the spacer cohort. Concerning the PROMS, all questionnaires showed no difference between the pre- and post-SBRT evaluation in both arms, excepting the physical functioning item of EORTC QLQ-C30 questionnaire that was declined in the no-spacer group. CONCLUSION: These preliminary results strongly suggest the adoption of perirectal spacer due to dosimetric advantages not only for rectal sparing but also for target coverage. Longer follow-up is required to validate the clinical impact in terms of clinicians-reported toxicity and PROMs. ADVANCES IN KNOWLEDGE: This the first experience reporting preliminary data concerning the potential dosimetric impact of rectal hydrogel spacer on MR-guided SBRT for prostate cancer.


Assuntos
Hidrogéis/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radiocirurgia/métodos , Reto/efeitos da radiação , Idoso , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Medidas de Resultados Relatados pelo Paciente , Estudos Prospectivos , Próstata/diagnóstico por imagem , Radiologia Intervencionista/métodos , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica
13.
PLoS One ; 15(12): e0242218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33370316

RESUMO

Improvements in survival rates with gonad-sparing protocols for childhood and adolescence cancer have increased the optimism of survivors to become parents after treatment. Findings in rodents indicate that chromosomal aberrations can be induced in male germ cells by genotoxic exposures and transmitted to offspring and future generations with effects on development, fertility and health. Thus, there is a need for effective technologies to identify human sperm carrying chromosomal aberrations to assess the germ-line risks, especially for cancer survivors who have received genotoxic therapies. The time-dependent changes in the burden of sperm carrying structural chromosomal aberrations were assessed for the first time in a cancer setting, using the AM8 sperm FISH protocol which simultaneously detects abnormalities in chromosomal structure and number in sperm. Nine Hodgkin lymphoma (HL) patients provided 20 semen samples before, during, and after NOVP therapy (Novantrone, Oncovin, Velban and Prednisone) and radiation therapy that produced scattered gonadal doses from <0.05 to 0.6 Gy. Late meiosis was found to be the most sensitive to NOVP treatment for the production of sperm with chromosomal abnormalities, both in structure and number. Earlier stages of spermatogenesis were less sensitive and there was no evidence that therapy-exposed stem cells resulted in increased frequencies of sperm with abnormalities in chromosomal structure or number. This indicates that NOVP therapy may increase the risks for paternal transmission of chromosomal structural aberrations for sperm produced 32 to 45 days after a treatment with these drugs and implies that there are no excess risks for pregnancies conceived more than 6 months after this therapy. This clinical evaluation of the AM8 sperm FISH protocol indicates that it is a promising tool for assessing an individual's burden of sperm carrying chromosomal structural aberrations as well as aneuploidies after cancer therapy, with broad applications in other clinical and environmental situations that may pose aneugenic or clastogenic risks to human spermatogenesis.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Aberrações Cromossômicas/efeitos dos fármacos , Doença de Hodgkin/terapia , Meiose/efeitos dos fármacos , Análise do Sêmen/métodos , Espermatozoides/efeitos dos fármacos , Adulto , Células-Tronco Germinativas Adultas/efeitos dos fármacos , Células-Tronco Germinativas Adultas/efeitos da radiação , Sobreviventes de Câncer , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Aberrações Cromossômicas/efeitos da radiação , Estudos de Coortes , Preservação da Fertilidade , Humanos , Hibridização in Situ Fluorescente/métodos , Masculino , Meiose/efeitos da radiação , Mitoxantrona/efeitos adversos , Mutagênese/efeitos dos fármacos , Mutagênese/efeitos da radiação , Tratamentos com Preservação do Órgão/efeitos adversos , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/efeitos da radiação , Prednisona/efeitos adversos , Dosagem Radioterapêutica , Espermatogênese/efeitos dos fármacos , Espermatogênese/efeitos da radiação , Espermatozoides/fisiologia , Espermatozoides/efeitos da radiação , Testículo/efeitos dos fármacos , Testículo/efeitos da radiação , Fatores de Tempo , Vimblastina/efeitos adversos , Vincristina/efeitos adversos
14.
J Cancer Res Ther ; 16(4): 726-730, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32930110

RESUMO

Purpose: The purpose of this study was to evaluate the organs at risk (OARs) doses for lung tumors in gated radiotherapy (RT) compared to conventional RT using the four-dimensional extended cardiac-torso (4D-XCAT) digital phantom in a simulation study. Materials and Methods: 4D-XCAT digital phantom was used to create 32 digital phantom datasets of different tumor diameters of 3 and 4 cm, and motion ranges (MRs) of 2, 2.5, 3, and 3.5 cm and each tumor was placed in four different lung locations (right lower lobe, right upper lobe, left lower lobe, and left upper lobe). XCAT raw binary images were converted to the digital imaging and communication in medicine format using an in-house MATLAB-based program and were imported to treatment planning system (TPS). For each dataset, gated and conventional treatment plans were prepared using Planning Computerized RadioTherapy-three dimensional (PCRT-3D) TPS with superposition computational algorithm. Dose differences between gated and conventional plans were evaluated and compared (as a function of 3D motion and tumor volume and its location) with respect to the dose-volume histograms of different organs-at-risk. Results: There are statistically significant differences in dosimetric parameters among gated and conventional RT, especially for the tumors near the diaphragm (P < 0.05). The maximum reduction in the mean dose of the lung, heart, and liver were 6.11 Gy, 1.51 Gy, and 10.49 Gy, respectively, using gated RT. Conclusions: Dosimetric comparison between gated and conventional RT showed that gated RT provides relevant dosimetric improvements to lung normal tissue and the other OARs, especially for the tumors near the diaphragm. In addition, dosimetric differences between gated and conventional RT did generally increase with increasing tumor motion and decreasing tumor volume.


Assuntos
Neoplasias Pulmonares/radioterapia , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada Quadridimensional/instrumentação , Tomografia Computadorizada Quadridimensional/métodos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Órgãos em Risco/diagnóstico por imagem , Imagens de Fantasmas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/instrumentação , Mecânica Respiratória , Carga Tumoral/efeitos da radiação
15.
J Cancer Res Ther ; 16(4): 888-899, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32930136

RESUMO

Context: Stereotactic body radiotherapy (SBRT) is increasingly being used for early-stage lung cancer and lung oligometastases. Aims: To report our experience of setting up lung SBRT and early clinical outcomes. Settings and Design: This was a retrospective, interventional, cohort study. Subjects and Methods: Patients were identified from multidisciplinary tumor board meetings. They underwent four-dimensional computed tomography-based planning. The ROSEL trial protocol, the Radiation Therapy Oncology Group (RTOG) 0236, and the UK-Stereotactic Ablative Body Radiotherapy Consortium guidelines were used for target volume and organs-at-risks (OARs) delineation, dosimetry, and plan quality assessment. Each SBRT plan underwent patient-specific quality assurance (QA). Daily online image guidance using KVCT or MVCT was done to ensure accurate treatment delivery. Statistical Analysis Used: Microsoft Excel 2010 was used for data analysis. Results: Fifteen patients were treated to one or more lung tumors. One patient received helical tomotherapy in view of bilateral lung oligometastases at similar axial levels. All the remaining patients received volumetric modulated arc therapy (VMAT)-based treatment. The prescription dose varied from 40 to 60 Gy in 5-8 fractions with alternate-day treatment. The mean and median lung V20 was 5.24% and 5.16%, respectively (range, 1.66%-9.10%). The mean and median conformity indexes were 1.02 and 1.06, respectively (range, 0.70-1.18). After a median follow-up of 17 months, the locoregional control rate was 93.3%. Conclusions: SBRT was implemented using careful evaluation of OAR dose constraints, dosimetric accuracy and plan quality, patient-specific QA, and online image guidance for accurate treatment delivery. It was safe and effective for early-stage nonsmall cell lung cancer and lung metastases. Prospective data were collected to audit our outcomes.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Tomografia Computadorizada Quadridimensional/métodos , Humanos , Índia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Órgãos em Risco/diagnóstico por imagem , Órgãos em Risco/efeitos da radiação , Garantia da Qualidade dos Cuidados de Saúde , Radiocirurgia/normas , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Centros de Atenção Terciária/organização & administração , Resultado do Tratamento
16.
Cancer Radiother ; 24(6-7): 594-601, 2020 Oct.
Artigo em Francês | MEDLINE | ID: mdl-32773282

RESUMO

Therapeutic strategies combining irradiation and drugs including chemotherapy, hormonotherapy, but also more recently targeted therapy and immunotherapy are routinely used for cancer treatment. Nevertheless, combined treatments usually lead to a rise in toxicity. In order to increase the therapeutic ratio in favour of a multimodality treatment, adapting dose constraints to organs at risk may be the key to lower the risk of toxicity. A review of the literature was conducted, focusing on the toxicity in dose-limiting organs at risk when radiation therapy is associated with drugs. Four situations were differentiated, including : 1) some contraindicated combinations due to an inacceptable increased of toxicity, or recommendations of careful use with restricted indications, reduction in prescribed dose, or severe dose constraints to organs at risk, 2) combined treatments without increased toxicity with no arguments for adjusted dose constraints, 3) associations with higher risk of toxicity, for which dose constraints could be adapted, 4) combined therapies with limited tolerance data, prohibiting their use out of clinical trials.


Assuntos
Quimiorradioterapia , Neoplasias/terapia , Órgãos em Risco/efeitos da radiação , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Humanos , Neoplasias/tratamento farmacológico , Dosagem Radioterapêutica
17.
Cancer Radiother ; 24(6-7): 586-593, 2020 Oct.
Artigo em Francês | MEDLINE | ID: mdl-32861607

RESUMO

Concurrent chemoradiotherapy improves the outcome of locally advanced head and neck cancers and the current reference chemotherapy is cisplatin. These results are obtained at the cost of increased toxicities. To limit the risk of toxicity, organ at riskdose constraints have been established starting with 2D radiotherapy, then 3D radiotherapy and intensity-modulated radiotherapy. Regarding grade ≥3 acute toxicities, the scientific literature attests that concurrent chemoradiotherapy significantly increases risks of mucositis and dysphagia. Constraints applied to the oral mucosa volume excluding the planning target volume, the pharyngeal constrictor muscles and the larynx limit this adverse impact. Regarding late toxicity, concurrent chemoradiotherapy increases significantly the risk of postoperative neck fibrosis and hearing loss. However, for some organs at risk, concurrent chemotherapy appears to increase late radiation induced effect, even though the results are less marked (brachial plexus, mandible, pharyngeal constrictor muscles, parotid gland). This additional adverse impact of concomitant chemotherapy may be notable only when organs at risk receive less than their usual dose thresholds and this would be vanished when those thresholds are exceeded as seems to be the situation for the parotid glands. Until the availability of more robust data, it seems appropriate to apply the principle of delivering dose to organs at risk as low as reasonably achievable.


Assuntos
Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/terapia , Órgãos em Risco/efeitos da radiação , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Humanos , Dosagem Radioterapêutica
18.
J Cancer Res Ther ; 16(3): 485-493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719255

RESUMO

Purpose: In this study, it is aimed to compare three different radiotherapy treatment planning techniques in terms of critical organ scoring index (COSI), two different conformity index (CI), tumor control probability (TCP), and normal tissue complication probability (NTCP) calculations in early (T1) glottic larynx carcinoma (T1GL). Furthermore, it is aimed to investigate these parameters compliance with dose-volume histograms (DVH) parameters. Materials and Methods: Ten T1GL patients were immobilized in a supine position with a head and neck thermoplastic mask. Treatment plans were created with opposed lateral fields (OLAFs) and intensity-modulated radiation therapy (IMRT) techniques with a total dose of 66 Gy in 33 fraction with 2 Gy/day. IMRT fields were selected as five fields (5IMRT) and seven fields (7IMRT). Dosimetric evaluation of three different treatment plans for T1GL carcinoma was performed in two consequential steps. First step was the assessment of planning target volume (PTV), all organs at risks (OARs), and normal tissue (NT) dose calculations according to given dose constraint directions and comparing the plans via DVH. In the second step, for PTV, the compatibility of DVH data with CIs-TCP was investigated where COSI-NTCP was compared with DVH for OARs. The DVH data were considered as reference in all evaluations. Results: The CIRTOG mean values were significantly closer to 1 with IMRT plans when compared to OLAF plans (P = 0.005). The CIPADDICK mean values revealed that OLAF plans were significantly worse than IMRT plans (P = 0.005). No statistically significant difference was found between all three plans in terms of homogeneity index mean values (P = 0.076). The calculated mean TCP values were significantly better for 7IMRT plans when compared to OLAF and 5IMRT plans (P = 0.007 and P = 0.017, respectively). Both NTCP and COSI evaluations, which is compatible with DVH, significantly favored OLAF plan for spinal cord and 7IMRT for thyroid gland. The COSI evaluations, which are compatible with DVH, significantly favored 7IMRT plan for carotid arteries and 5IMRT plan for NT. Conclusion: Our results demonstrated that CIPADDICK-TCP calculations for PTV and COSI-NTCP calculations for OARs were compatible with DVH in T1 GL plans. Therefore, we suggest such parameters as valuable tools for choosing the feasible one among multiple plans and even with different treatment machines.


Assuntos
Algoritmos , Glote/efeitos da radiação , Neoplasias Laríngeas/radioterapia , Laringe/efeitos da radiação , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Glote/patologia , Humanos , Neoplasias Laríngeas/patologia , Laringe/patologia , Radiometria/métodos , Dosagem Radioterapêutica
19.
J Cancer Res Ther ; 16(3): 600-604, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719274

RESUMO

Background: Radiotherapy in head-and-neck cancer (HNC) is a challenging task, and the anatomical alterations occurring during the course of intensity-modulated radiotherapy (IMRT) can be compensated by adaptive radiotherapy (ART) which utilizes repeat computed tomography (CT) scans during the treatment course for replanning. In this study, the clinical and dosimetric benefits of ART were compared with the conventional IMRT. Materials and Methods: Sixty patients with locally advanced HNC were randomized into two arms to receive IMRT up to a curative dose of 70 Gy with concurrent weekly chemotherapy and were prospectively analyzed between March 2018 and March 2019. Repeat CT scan was acquired after the 3rd week of radiation. Patients in the study arm underwent replanning, whereas those in the control arm continued with the first IMRT plan. Assessment was done weekly till the end of treatment and at 1, 3, and 6 months post IMRT for disease response and toxicities. Tumor volume reduction rate (TVRR) and dose reduction to organs at risk were also recorded. Results: Complete response was observed in 90% and 96.7% patients in the control and study arms, respectively, at the end of 6 months. Insignificant differences were found between the two arms in terms of toxicities. Xerostomia was statistically significantly higher in the control arm at 6 months (P = 0.01). TVRR was found to be 31.85%. Dose to spinal cord, ipsilateral, and contralateral parotid reduced by 4.3%, 6%, and 2.2%, respectively, with ART. Conclusion: Mid-treatment adaptive replanning can help in better target coverage and minimize toxicities in HNC patients.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Adolescente , Adulto , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco/diagnóstico por imagem , Estudos Prospectivos , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos , Carga Tumoral/efeitos da radiação , Adulto Jovem
20.
Phys Med Biol ; 65(17): 175014, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32663813

RESUMO

The purpose of this work was to develop a deep learning (DL) based algorithm, Automatic intensity-modulated radiotherapy (IMRT) Planning via Static Field Fluence Prediction (AIP-SFFP), for automated prostate IMRT planning with real-time planning efficiency. The following method was adopted: AIP-SFFP generates a prostate IMRT plan through predictions of fluence maps using patient anatomy. No inverse planning is required. AIP-SFFP is centered on a custom-built deep learning (DL) neural network for fluence map prediction. Predictions are imported to a commercial treatment-planning system for dose calculation and plan generation. AIP-SFFP was demonstrated for prostate IMRT simultaneously-integrated-boost planning (58.8 Gy/70 Gy to PTV58.8 Gy/PTV70 Gy in 28 fx, PTV = Planning Target Volume). Training data was generated from 106 patients using a knowledge-based planning (KBP) plan generator. Two types of 2D projection images were designed to represent structures' sizes and locations, and a total of eight projections were utilized to describe targets and organs-at-risk. Projections at nine template beam angles were stacked as inputs for artificial intelligence (AI) training. 14 patients were used as independent tests. The generated test plans were compared with the plans from the KBP training plan generator and clinic practice. The following results were obtained: After normalization (PTV70 Gy V70 Gy = 95%), all 14 AI plans met institutional criteria. The coverage of PTV58.8 Gy in the AI plans was comparable to KBP and clinic plans without statistical significance. The whole body (BODY) D1cc and rectum D0.1cc of AI plans were slightly higher (<1 Gy) compared to KBP and clinic plans; in contrast, the bladder D1cc and other rectum and bladder low doses in the AI plans were slightly improved without clinical relevance. The overall isodose distribution in the AI plans was comparable with KBP plans and clinical plans. AIP-SFFP generated each test plan within 20s including the prediction and the dose calculation. In conclusion, AIP-SFFP was successfully developed for prostate IMRT planning. AIP-SFFP demonstrated good overall plan quality and real-time efficiency. Showing great promise, AIP-SFFP will be investigated for immediate clinical application.


Assuntos
Aprendizado Profundo , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada , Automação , Humanos , Masculino , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/efeitos adversos
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