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1.
J Appl Clin Med Phys ; 17(6): 429-433, 2016 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-27929514

RESUMO

The purpose of this study was to evaluate bilateral kidney and target translational/rotational intrafraction motion during stereotactic body radiation therapy treatment delivery of primary renal cell carcinoma and oligometastatic adrenal lesions for patients immobilized in the Elekta BodyFIX system. Bilateral kidney motion was assessed at midplane for 30 patients immobilized in a full-body dual-vacuum-cushion system with two patients immobilized via abdominal compression. Intrafraction motion was assessed for 15 patients using kilovoltage cone-beam computed tomography (kV-CBCT) datasets (n = 151) correlated to the planning CT. Patient positioning was corrected for translational and rotational misalign-ments using a robotic couch in six degrees of freedom if setup errors exceeded 1mm and 1°. Absolute bilateral kidney motion between inhale and exhale 4D CT imaging phases for left-right (LR), superior-inferior (SI), and anterior-posterior (AP) directions was 1.51 ± 1.00 mm, 8.10 ± 4.33 mm, and 3.08 ± 2.11 mm, respec-tively. Residual setup error determined across CBCT type (pretreatment, intrafrac-tion, and post-treatment) for x (LR), y (SI), and z (AP) translations was 0.63 ± 0.74 mm, 1.08± 1.38 mm, and 0.70 ± 1.00 mm; while for x (pitch), y (roll), and z (yaw) rotations was 0.24 ± 0.39°, 0.19 ± 0.34°, and 0.26 ± 0.43°, respectively. Targets were localized to within 2.1 mm and 0.8° 95% of the time. The frequency of misalignments in the y direction was significant (p < 0.05) when compared to the x and z directions with no significant difference in translations between IMRT and VMAT. This technique is robust using BodyFIX for patient immobilization and reproducible localization of kidney and adrenal targets and daily CBCT image guidance for correction of positional errors to maintain treatment accuracy.


Assuntos
Neoplasias Abdominais/cirurgia , Rim/efeitos da radiação , Movimento , Posicionamento do Paciente , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Erros de Configuração em Radioterapia/prevenção & controle , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Imobilização , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos
2.
Future Oncol ; 10(14): 2227-41, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25471036

RESUMO

Although liver-directed therapies such as surgery or ablation can cure hepatocellular carcinoma, few patients are eligible due to advanced disease or medical comorbidities. In advanced disease, systemic therapies have yielded only incremental survival benefits. Historically, radiotherapy for liver cancer was dismissed due to concerns over unacceptable toxicities from even moderate doses. Although implementation requires more resources than standard radiotherapy, stereotactic body radiotherapy can deliver reproducible, highly conformal ablative radiotherapy to tumors while minimizing doses to nearby critical structures. Trials of stereotactic body radiotherapy for hepatocellular carcinoma have demonstrated promising local control and survival results with low levels of toxicity in Child-Pugh class A patients. We review the published literature and make recommendations for the future of this emerging modality.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Radiocirurgia , Carcinoma Hepatocelular/diagnóstico , Gerenciamento Clínico , Humanos , Neoplasias Hepáticas/diagnóstico , Estadiamento de Neoplasias , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador , Fatores de Risco , Resultado do Tratamento
3.
Artigo em Inglês | MEDLINE | ID: mdl-39293531

RESUMO

PURPOSE: SABR is growingly accepted for the treatment of localized prostate cancer with recent randomized trials showing noninferiority compared with conventional or moderately hypofractionated radiation therapy. The natural history of prostate cancer necessitates extended surveillance for recurrence; however, there are a few prospective studies reporting long-term outcomes. METHODS AND MATERIALS: This study included patients with low- and intermediate-risk localized prostate cancer from 3 Canadian clinical trials enrolled from 2006 to 2013. All patients received SABR to the prostate consisting of 35 to 40 Gy in 5 fractions over 11 to 29 days. Prostate specific antigen, distant metastasis, and vital status were prospectively recorded. The occurrence of a second malignancy after treatment was assessed by a chart review and classified using modified Cahan's criteria. RESULTS: Two hundred sixty-seven patients were included. Median follow-up was 10.3 years (interquartile range, 7.8-12.7). Ten-year biochemical failure (95% confidence interval) was 7.7% (3.9%-11.5%); 10-year overall survival, prostate cancer-specific survival, and freedom from metastasis were 84.1% (79.3%-89.1%), 99.2% (98.1%-100%), and 98.8% (97.5%-100%), respectively. Twenty-seven of 267 (10.1%) patients experienced a second malignancy (SM), with 6/27 patients (22.2%) classified as having a SM likely (n = 3) or possibly (n = 3) related to prior radiation therapy. Ten-year freedom from SM was 89.2%. CONCLUSIONS: SABR shows excellent long-term disease control for low- and intermediate-risk localized prostate cancer. Patients treated for prostate cancer have a moderate risk of SM, consistent with background rates for the population.

4.
Int J Radiat Oncol Biol Phys ; 115(4): 897-905, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36368432

RESUMO

PURPOSE: With the increasing use of stereotactic body radiation therapy (SBRT) for primary and metastatic cancer, use of multitarget thoracic (MTT) SBRT is rising. Given the limited safety and efficacy data, we report the experience of this strategy from a large academic center. METHODS AND MATERIALS: Between 2012 and 2021, patients who received SBRT for ≥2 thoracic targets separated by ≤1 year were retrospectively reviewed. The primary endpoint was clinically significant radiation pneumonitis (CSRP) requiring steroids, oxygen, or intubation. Secondary endpoints included local failure (LF), initiation or change of systemic therapy (ICST), progression-free survival, and overall survival. Competing risk analysis was used to evaluate the cumulative incidence of CSRP, LF, and ICST. Univariate and multivariable analyses were performed to look for clinical and dosimetric predictive factors of CSRP and LF. RESULTS: One hundred ninety patients (481 lesions) were treated with MTT SBRT with a median follow-up of 19.7 months. Indications for SBRT were oligometastases (n = 70; 36.8%), oligoprogression (n = 62; 32.6%), curative intent in patients with primary lung cancer (n = 37; 19.5%), and control of dominant areas of metastatic progression (n = 21; 11.0%). The number of irradiated tumors ranged from 2 to 7 and the majority of SBRT courses were delivered simultaneously (88.2%). Overall, 14 patients (7.4%) had CSRP, with 5 cases requiring oxygen. The cumulative incidence of CSRP at 6 and 12 months was 5.3% and 7.6%, respectively. The cumulative incidence of LF at 2 years was 10.5%. The cumulative incidence of ICST at 2 years was 41.1%. Median progression-free survival was 11.8 months and median overall survival was 51.3 months. On multivariable analysis, a higher lung V35Gy (hazard ratio, 2.59; P = .02) was a statistically significant predictor of CSRP and colorectal histology predicted for higher LF (hazard ratio, 2.12; P = .02). CONCLUSIONS: In one of the largest institutional series of MTT SBRT, rates of CSRP and LF were low. Optimizing plans to lower the lung V35Gy may decrease the risk of CSRP.


Assuntos
Neoplasias Pulmonares , Pneumonite por Radiação , Radiocirurgia , Humanos , Neoplasias Pulmonares/patologia , Estudos Retrospectivos , Radiocirurgia/métodos , Pulmão/patologia , Intervalo Livre de Progressão , Pneumonite por Radiação/etiologia , Resultado do Tratamento
5.
Radiother Oncol ; 186: 109792, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37414253

RESUMO

PURPOSE: Stereotactic Body Radiation Therapy (SBRT) is increasingly applied to treat non-spine bone metastases (NSBM) though data remains limited on this approach. In this retrospective study, we report outcomes and predictors of local failure (LF) and pathological fracture (PF) post-SBRT for NSBM using a mature single-institution database. METHODS: Patients with NSBM treated with SBRT between 2011 and 2021 were identified. The primary objective was to assess the rates of radiographic LF. Secondary objectives were to assess the rates of in-field PF, overall survival (OS), and late grade ≥ 3 toxicity. Competing risks analysis was used to assess rates of LF and PF. Univariable regression and multivariable regression (MVR) were performed to investigate predictors of LF and PF. RESULTS: A total of 373 patients with 505 NSBM were included in this study. Median follow-up was 26.5 months. The cumulative incidence of LF at 6, 12, and 24 months were 5.7%, 7.9%, and 12.6%, respectively. The cumulative incidence of PF at 6, 12, and 24 months were 3.8%, 6.1%, and 10.9%, respectively. Lytic NSBM (HR = 2.18; p < 0.01), a lower biologically effective dose (HR = 1.11 per 5 Gy10 decrease; p = 0.04), and a PTV ≥ 54 cc (HR = 4.32; p < 0.01) predicted for a higher risk of LF on MVR. Lytic NSBM (HR = 3.43; p < 0.01), mixed (lytic/sclerotic) lesions (HR = 2.70; p = 0.04), and rib metastases (HR = 2.68; p < 0.01) predicted for a higher risk of PF on MVR. CONCLUSION: SBRT is an effective modality to treat NSBM with high rates of radiographic local control with an acceptable rate of PF. We identify predictors of both LF and PF that can serve to inform practice and trial design.


Assuntos
Fraturas Espontâneas , Neoplasias Pulmonares , Radiocirurgia , Humanos , Fraturas Espontâneas/etiologia , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Neoplasias Pulmonares/patologia , Incidência
6.
Cureus ; 12(9): e10618, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-33123432

RESUMO

Introduction Despite treatment advances, the prognosis of locally advanced pancreatic cancer is poor. Treatment remains varied and includes systemic and radiotherapy (RT). Stereotactic body radiotherapy (SBRT), highly conformal high-dose RT per fraction, is an emerging treatment option. Materials and methods We performed a single-institution retrospective review of patients with pancreatic adenocarcinoma treated with SBRT from 2015-2017. The median dose was 27 Gy (range: 21-36 Gy) in three fractions. Endpoints included local progression (RECIST 1.1; Response Evaluation Criteria in Solid Tumors 1.1), distant metastasis, overall survival, and toxicity. Results Forty-one patients were treated, with a median follow-up of eight months. Patients who received SBRT had unresectable (49%), metastatic (17%), or borderline resectable (7%) disease, declined surgery (17%), medically inoperable (7%), or developed local recurrence following the Whipple procedure (2%). The six-month and one-year rates of local progression-free survival, distant metastasis-free survival, and overall survival were 62% and 55%, 44% and 32%, and 70% and 49%, respectively. Five patients (12%) experienced seven late gastrointestinal (GI) grade 3 events. Conclusion  SBRT may be considered a treatment option to achieve local control of pancreatic cancer and is associated with a modest risk of severe late GI toxicities. Systemic therapies remain important, given the proportion of patients who develop distant metastases.

7.
Radiother Oncol ; 149: 8-13, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32416376

RESUMO

BACKGROUND: Prostate stereotactic ablative radiotherapy (SABR) regimens differ in time, dose, and fractionation. We report an update of a multicentre, Canadian randomized phase II study to investigate the impact of overall treatment time on quality of life (QOL), efficacy, and toxicity. METHODS: Men with intermediate risk prostate cancer were randomized to 40 Gy in 5 fractions delivered every other day (EOD) versus once per week (QW). Primary outcome was proportion of patients experiencing a minimally clinically important change (MCIC) in acute bowel QOL using EPIC. Secondary outcomes were toxicity, biochemical failure (BF), other QOL domains, and the rate of salvage therapy. FINDINGS: 152 men from 3 centers were randomized; the median follow-up was 62 months. Results are described for EOD versus QW. Acute bowel and urinary QOL was reported previously. Late changes in QOL were not significantly different between the two arms. There were 1 (1.3%) vs 3 (2.7%) late grade 3 + GI toxicities (p = 0.36) and 5 (6.7%) vs 2 (2.7%) late grade 3 GU toxicities (p = 0.44). Two and 5 patients had BF (5-year failure rate 3.0 vs 7.2%, p = 0.22); 0 and 4 patients received salvage therapy (p = 0.04). 5-Year OS and CSS was 95.8% and 98.6% with no difference between arms (p = 0.49, p = 0.15). 3 patients in the QW arm developed metastases. INTERPRETATION: Although we previously reported that weekly prostate SABR had better bowel and urinary QOL compared to EOD, the updated results show no difference in late toxicity, QOL, BF, or PSA kinetics. Patients should be counseled that QW SABR reduces short-term toxicity compared to QW SABR.


Assuntos
Neoplasias da Próstata , Radiocirurgia , Canadá , Fracionamento da Dose de Radiação , Humanos , Masculino , Próstata , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Qualidade de Vida , Radiocirurgia/efeitos adversos
8.
Radiother Oncol ; 144: 135-140, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31809979

RESUMO

PURPOSE: SABR offers an effective treatment option for clinically localized prostate cancer. Here we report the dosimetric predictors of late toxicity and quality of life (QOL) in a pooled cohort of patients from four phase II trials. METHODS: The combined cohort included all three prostate cancer risk groups. The prescription dose was 35-40 Gy in 5 fractions. Toxicity (CTCAE) and QOL (EPIC) were collected. Multiple dosimetric parameters for the bladder, rectum and penile bulb were collected. Univariate (UVA) followed by multivariate (MVA) logistic regression analysis was conducted to search for significant dosimetric predictors of late GI/GU toxicity, or minimal clinically important change in the relevant QOL domain. RESULTS: 258 patients were included with median follow up of 6.1 years. For QOL, bladder Dmax, V38, D1cc, D2cc, D5cc and rectal V35 were predictors of urinary and bowel MCIC on UVA. On MVA, only bladder V38 remained significant. For late toxicity, various parameters were significant on UVA but only rectal Dmax, V38 and bladder D2cc were significant predictors on MVA. CONCLUSIONS: This report confirms that the high-dose regions in the bladder and rectum are more significant predictors of late toxicity and QOL after prostate SABR compared to low-dose regions. Caution must be taken to avoid high doses and hotspots in those organs.


Assuntos
Neoplasias da Próstata , Lesões por Radiação , Radiocirurgia , Humanos , Masculino , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Qualidade de Vida , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Reto
9.
Int J Radiat Oncol Biol Phys ; 107(1): 136-142, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987962

RESUMO

PURPOSE: Dose-escalated stereotactic ablative radiotherapy (SABR) to the whole prostate may be associated with better outcomes but has a risk of increased toxicity. An alternative approach is to focally boost the dominant intraprostatic lesion (DIL) seen on magnetic resonance imaging. We report the toxicity and quality-of-life (QOL) outcomes of 2 phase 2 trials of prostate and pelvic SABR, with or without a simultaneous DIL boost. METHODS AND MATERIALS: The first trial treated patients with high-risk prostate cancer to a dose of 40 Gy to the prostate and 25 Gy to the pelvis in 5 fractions. The second trial treated patients with intermediate-risk and high-risk prostate cancer to a dose of 35 Gy to the prostate, 25 Gy to the pelvis, and a DIL boost up to 50 Gy in 5 fractions. Acute toxicities, late toxicities, and QOL were assessed. RESULTS: Thirty patients were enrolled in each trial. In the focal boost cohort, the median DIL D90% was 48.3 Gy. There was no significant difference in acute grade ≥2 gastrointestinal or genitourinary toxicity between the 2 trials or in cumulative worst late gastrointestinal or genitourinary toxicity up to 24 months. There was no significant difference in QOL domain scores or minimally clinical important change between the 2 trials. CONCLUSIONS: Prostate and pelvic SABR with a simultaneous DIL boost was feasible. Acute grade ≥2 toxicity, late toxicity, and QOL seemed to be comparable to a cohort that did not receive a focal boost. Further follow-up will be required to assess long-term outcomes, and randomized data are required to confirm these findings.


Assuntos
Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Qualidade de Vida , Radiocirurgia/efeitos adversos , Segurança , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fatores de Tempo
10.
Radiother Oncol ; 140: 105-109, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31265940

RESUMO

PURPOSE: Stereotactic ablative radiotherapy (SABR) is appealing for prostate cancer (PCa) due to low α/ß, and increasing the dose per fraction could improve the therapeutic index and lead to a better quality of life (QOL). Here we report the outcomes of a QOL comparison between two phase II clinical trials: two vs. five fraction prostate SABR. METHODS: Patients had low or intermediate risk PCa. The doses prescribed were 26 Gy/2 and 40 Gy/5. Expanded prostate cancer index composite was collected. Urinary, bowel and sexual domains were analyzed. Minimal clinically important change (MCIC) was defined as >0.5 standard deviation. RESULTS: 30 and 152 patients were treated with 2-fraction and 5-fraction SABR. Median follow-up was 55 and 62 months. Five-year biochemical failure rate was 3.3% and 4.6%. The 2-fraction cohort had a significantly better mean QOL over time in the bowel domain (p = 0.0004), without a significant difference in the urinary or sexual domains. The 2-fraction cohort had a significantly lower rate of bowel MCIC (17.8% vs 42.3%, p = 0.01), but there was no difference in urinary (24.1% vs 35.7%) or sexual (15.3% vs 29.2%) MCIC. For MCIC x2 (moderate QOL change), the 2-fraction trial had significantly lower MCIC rates in both the bowel (7.1% vs 24%, p = 0.04) and sexual (0 vs 17.6%, p = 0.01) domains. CONCLUSIONS: 2-Fraction SABR is feasible to deliver and well tolerated, with significant signals of improved bowel and sexual QOL. A randomized trial of two vs. five fractions for prostate SABR is needed to confirm the promising findings of this study.


Assuntos
Neoplasias da Próstata/radioterapia , Qualidade de Vida , Radiocirurgia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Próstata/psicologia , Radiocirurgia/efeitos adversos
11.
Radiother Oncol ; 129(3): 435-440, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30274721

RESUMO

PURPOSE: To report the changes in quality of life (QoL) after stereotactic ablative radiotherapy (SABR) in patients with liver metastases (LM). MATERIALS AND METHODS: A prospective cohort study was undertaken to measure the acute changes in QoL after SABR. Patients with 1-3 treated LM were eligible. Doses of 30-60 Gy in 3-5 fractions were delivered. Prospective QoL was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaires, Core 15 for Palliative Care (EORTC QLQ-C15-PAL) and liver metastases (LM21), at baseline, 1st week and last day of treatment, then 1, 6 and 12 weeks after SABR. The functional living index-emesis (FLIE) was collected at baseline, 1st week, last day and 1 week after treatment. Univariable and multivariable linear mixed modeling were performed as appropriate to assess changes in QoL over time. RESULTS: Sixty patients were included. The most common primary cancer was colorectal (42%). The global health score measured by QLQ-C15-PAL was significantly worse at treatment completion (p = 0.001), 1 week (p = 0.003) and 6 weeks (p = 0.002) after SABR but recovered by 12 weeks (p = 0.124). Nausea and constipation were worse at treatment completion (p < 0.05) but recovered 1 week after while fatigue recovered 6 weeks post-SABR. The majority of patients reported stable QoL at 12 weeks for all domains in the C15-PAL and LM21 questionnaires. CONCLUSION: SABR offers a non-invasive mean of ablating LM with minimal impact on acute QoL.


Assuntos
Neoplasias Hepáticas/radioterapia , Qualidade de Vida , Radiocirurgia/métodos , Idoso , Neoplasias Colorretais , Constipação Intestinal/etiologia , Fadiga/etiologia , Feminino , Nível de Saúde , Humanos , Neoplasias Hepáticas/psicologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Náusea/etiologia , Metástase Neoplásica , Cuidados Paliativos/métodos , Estudos Prospectivos , Radiocirurgia/efeitos adversos , Inquéritos e Questionários
12.
Radiother Oncol ; 127(2): 206-212, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29551231

RESUMO

BACKGROUND AND PURPOSE: Prostate stereotactic body radiotherapy (SBRT) regimens differ in time, dose, and fractionation. We completed a multicentre, randomized phase II study to investigate the impact of overall treatment time on quality of life (QOL). MATERIAL AND METHODS: Men with low and intermediate-risk prostate cancer were randomly assigned to 40 Gy in 5 fractions delivered once per week (QW) vs. every other day (EOD). QOL was assessed using the Expanded Prostate Cancer Index Composite. The primary endpoint was the proportion with a minimum clinically important change (MCIC) in bowel QOL during the acute (≤12 week) period, and analysis was by intention-to-treat. ClinicalTrials.gov NCT01423474. RESULTS: 152 men from 3 centres were randomized with median follow-up of 47 months. Patients treated QW had superior acute bowel QOL with 47/69 (68%) reporting a MCIC compared to 63/70 (90%) treated EOD (p = 0.002). Fewer patients treated QW reported moderate-severe problems with bowel QOL during the acute period compared with EOD (14/70 [20%] vs. 40/70 [57%], p < 0.001). Acute urinary QOL was also better in the QW arm, with 52/67 (78%) vs 65/69 (94%) experiencing a MCIC (p = 0.006). There were no significant differences in late urinary or bowel QOL at 2 years or last follow-up. CONCLUSION: Prostate SBRT delivered QW improved acute bowel and urinary QOL compared to EOD. Patients should be counselled regarding the potential for reduced short-term toxicity and improved QOL with QW prostate SBRT.


Assuntos
Neoplasias da Próstata/radioterapia , Radiocirurgia/métodos , Idoso , Fracionamento da Dose de Radiação , Gastroenteropatias/etiologia , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Lesões por Radiação/etiologia , Radiocirurgia/efeitos adversos , Fatores de Tempo , Transtornos Urinários/etiologia
13.
J Biomed Opt ; 12(2): 024011, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17477726

RESUMO

Tissue remodeling during maturation, wound healing, and response to vascular stress involves molecular changes of collagen and elastin in the extracellular matrix (ECM). Two optical techniques are effective for investigating these changes--laser-induced fluorescence (LIF) spectroscopy and polarizing microscopy. LIF spectroscopy integrates the signal from both elastin and collagen cross-linked structure, whereas birefringence is a measure of only collagen. Our purpose is (1) to evaluate the rat tail tendon (RTT) spectroscopy against data from purified extracted protein standards and (2) to correlate the two optical techniques in the study of RTT and skin. Spectra from tissue samples from 27 male rats and from extracted elastin and collagen were obtained using LIF spectroscopy (357 nm). Birefringence was measured on 5-mum histological sections of the same tissue. Morphometric analysis reveals that elastin represents approximately 10% of tendon volume and contributes to RTT fluorescence. RTT maximum fluorescence emission intensity (FEI(max)), which includes collagen and elastin, increases with animal weight (R(2)=0.64). Birefringence, when plotted against weight, increases to a plateau (nonlinear correlation: R(2)=0.90), tendon having greater birefringence than skin. LIF spectroscopy and collagen fiber birefringence are shown to provide complementary measurements of molecular structure (tendon birefringence versus FEI(max) at R(2)=0.60).


Assuntos
Envelhecimento/metabolismo , Colágeno/metabolismo , Elastina/metabolismo , Refratometria/métodos , Espectrometria de Fluorescência/métodos , Cauda/fisiologia , Tendões/fisiologia , Animais , Birrefringência , Masculino , Ratos , Ratos Wistar , Distribuição Tecidual
14.
Technol Cancer Res Treat ; 16(2): 231-237, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28279146

RESUMO

The aim of this study is to determine whether stereotactic body radiotherapy for multiple vertebral metastases treated with a single isocenter results in greater intrafraction errors than stereotactic body radiotherapy for single vertebral metastases and to determine whether the currently used spinal cord planning organ at risk volume and planning target volume margins are appropriate. Intrafraction errors were assessed for 65 stereotactic body radiotherapy treatments for vertebral metastases. Cone beam computed tomography images were acquired before, during, and after treatment for each fraction. Residual translational and rotational errors in patient positioning were recorded and planning organ at risk volume and planning target volume margins were calculated in each direction using this information. The mean translational residual errors were smaller for single (0.4 (0.4) mm) than for multiple vertebral metastases (0.5 (0.7) mm; P = .0019). The mean rotational residual errors were similar for single (0.3° (0.3°) and multiple vertebral metastases (0.3° (0.3°); P = .862). The maximum calculated planning organ at risk volume margin in any direction was 0.83 mm for single and 1.22 for multiple vertebral metastases. The maximum calculated planning target volume margin in any direction was 1.4 mm for single and 1.9 mm for multiple vertebral metastases. Intrafraction errors were small for both single and multiple vertebral metastases, indicating that our strategy for patient immobilization and repositioning is robust. Calculated planning organ at risk volume and planning target volume margins were smaller than our clinically employed margins, indicating that our clinical margins are appropriate.


Assuntos
Posicionamento do Paciente , Radiocirurgia , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/secundário , Tomografia Computadorizada de Feixe Cônico , Fracionamento da Dose de Radiação , Humanos , Imageamento por Ressonância Magnética , Radiocirurgia/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia Guiada por Imagem , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/patologia , Carga Tumoral
15.
Med Dosim ; 41(4): 323-328, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27745995

RESUMO

To develop a volumetric modulated arc therapy (VMAT) treatment planning solution in the treatment of primary renal cell carcinoma and oligometastatic adrenal lesions with stereotactic body radiation therapy. Single-arc VMAT plans (n = 5) were compared with clinically delivered step-and-shoot intensity-modulated radiotherapy (IMRT) with planning target volume coverage normalized between techniques. Target volume conformity, organ-at-risk (OAR) dose, treatment time, and monitor units were compared. A VMAT planning solution, created from a combination of arc settings and optimization constraints, auto-generated treatment plans in a single optimization. The treatment planning solution was evaluated on 15 consecutive patients receiving kidney and adrenal stereotactic body radiation therapy. Treatment time was reduced from 13.0 ± 2.6 to 4.0 ± 0.9 minutes for IMRT and VMAT, respectively. The VMAT planning solution generated treatment plans with increased target homogeneity, improved 95% conformity index, and a reduced maximum point dose to nearby OARs but with increased intermediate dose to distant OARs. The conformity of the 95% isodose improved from 1.32 ± 0.39 to 1.12 ± 0.05 for IMRT and VMAT treatment plans, respectively. Evaluation of the planning solution showed clinically acceptable dose distributions for 13 of 15 cases with tight conformity of the prescription isodose to the planning target volume of 1.07 ± 0.04, delivering minimal dose to OARs. The introduction of a stereotactic body radiation therapy VMAT treatment planning solution improves the efficiency of planning and delivery time, producing treatment plans of comparable or superior quality to IMRT in the case of primary renal cell carcinoma and oligometastatic adrenal lesions.


Assuntos
Neoplasias das Glândulas Suprarrenais/radioterapia , Carcinoma de Células Renais/radioterapia , Neoplasias Renais/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias das Glândulas Suprarrenais/patologia , Humanos , Metástase Neoplásica , Órgãos em Risco , Dosagem Radioterapêutica
16.
Photochem Photobiol ; 81(2): 457-66, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15560737

RESUMO

Altered collagen and elastin content correlates closely with remodeling of the arterial wall after injury. Optical analytical approaches have been shown to detect qualitative changes in plaque composition, but the capacity for detection of quantitative changes in arterial collagen and elastin content in vivo is not known. We have assessed fluorescence spectroscopy for detection of quantitative changes in arterial composition in situ, in rabbit models of angioplasty and stent implant. Fluorescence emission intensity (FEI) recorded at sites remote from the primary implant site was correlated with immunohistochemical (IH) analysis and extracted elastin and collagen. FEI was significantly decreased (P<0.05) after treatment with anti-inflammatory agents, and plaque area decreased on comparison with saline-treated rabbits after stent implant or angioplasty (Por=0.961) analysis were detected by multiple regression (MR) analysis. Good correlations also were found for FEI with elastin and collagen measured by high-performance liquid chromatography; MR analysis provided highly predictive values for collagen and elastin (R2>or=0.994). Fluorescence spectroscopic analysis detects quantitative compositional changes in arterial connective tissue in vivo, demonstrating changes at sites remote from primary angioplasty and stent implant sites.


Assuntos
Arteriosclerose/metabolismo , Colágeno/química , Elastina/química , Artéria Femoral/química , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Arteriosclerose/induzido quimicamente , Arteriosclerose/tratamento farmacológico , Colesterol na Dieta/administração & dosagem , Colágeno/metabolismo , Modelos Animais de Doenças , Elastina/metabolismo , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/cirurgia , Fluorescência , Imuno-Histoquímica , Óptica e Fotônica , Coelhos , Espectrometria de Fluorescência , Coloração e Rotulagem , Stents
17.
J Neurosurg Spine ; 21(5): 711-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25170656

RESUMO

OBJECT: The aim of this study was to evaluate local control (LC) and the risk of vertebral compression fracture (VCF) after stereotactic body radiotherapy (SBRT) in patients with renal cell cancer spinal metastases. METHODS: Prospectively collected data on 71 spinal segments treated with SBRT in 37 patients were reviewed. The median follow-up was 12.3 months (range 1.2-55.4 months). The LC rate was assessed based on each spinal segment treated and overall survival (OS) according to each patient treated. Sixty of 71 segments (85%) were radiation naive, 11 of 71 (15%) were previously irradiated, and 10 of 71 (14%) were treated with postoperative SBRT. The median SBRT total dose and number of fractions were 24 Gy and 2, respectively. The VCF analysis also included evaluation of the Spinal Instability Neoplastic Score criteria. RESULTS: The 1-year OS and LC rates were 64% and 83%, respectively. Multivariate analysis identified oligometastatic disease (13 of 37 patients) as a positive prognostic factor (p = 0.018) for OS. Of 61 non-postoperative spinal segments treated, 10 (16%) developed VCFs; 3 of 10 were de novo VCFs and 7 of 10 occurred as progression of an existing VCF. The 1-year VCF-free probability rate was 82%. Multivariate analysis identified single-fraction SBRT and baseline VCF as significant predictors of SBRT-induced VCF (p = 0.028 and p = 0.012, respectively). CONCLUSIONS: Spine SBRT yields high rates of local tumor control in patients with renal cell cancer. Baseline VCF and 18-24 Gy delivered in a single fraction were predictive of further collapse. Patients with oligometastatic disease may benefit most from such aggressive local therapy, given the prolonged survival observed.


Assuntos
Carcinoma de Células Renais/secundário , Carcinoma de Células Renais/cirurgia , Neoplasias Renais/patologia , Radiocirurgia , Neoplasias da Coluna Vertebral/secundário , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas por Compressão/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Radiocirurgia/efeitos adversos , Fraturas da Coluna Vertebral/etiologia
18.
J Med Imaging Radiat Sci ; 44(3): 126-133, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31052036

RESUMO

Conventional low-dose radiation therapy (RT) has long been used in the treatment of patients suffering from the symptoms of metastatic cancer in and around the spine. The goals of therapy include pain control and at least short-term local disease control. Most patients are offered palliative doses such as 8 Gy in one fraction, 20 Gy in five fractions, or 30 Gy in 10 fractions, and as yet there has been no dose-response relationship within conventional RT practice. Stereotactic body radiation therapy (SBRT) is a relatively new technique that overcomes the previous limitations of conventional RT by delivering high biologically effective doses (BED), in the range of what is considered locally curative, using intensity-modulated radiotherapy (IMRT). Doses such as 16-24 Gy in a single fraction, 24-30 Gy in two or three fractions, and 30-40 Gy in four or five fractions are commonly used in spine SBRT, while sparing the surrounding normal tissues to a much lower dose that falls within tolerance. The high precision required for spine SBRT demands near-rigid patient immobilization, visualization of the target volume and spinal cord with magnetic resonance imaging, and image-guided radiotherapy. Ultimately, an overall delivery precision of approximately 1.5-2 mm is required for safe and effective treatment. The aim of this review is to discuss the technical delivery of spine SBRT with particular attention to the incorporation of robotic treatment couch technology. The HexaPOD (Elekta AB, Stockholm, Sweden) is the robotic couch in use at the University of Toronto, and it is capable of performing fine translations and rotations allowing for six degrees of freedom patient positioning. This technology is a major advancement in correcting patient setup errors.

19.
Int J Radiat Oncol Biol Phys ; 86(4): 638-42, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23664326

RESUMO

PURPOSE: To determine the incidence of pain flare after spine stereotactic body radiation therapy (SBRT) in steroid-naïve patients and identify predictive factors. METHODS AND MATERIALS: Forty-one patients were treated with spine SBRT between February 2010 and April 2012. All patients had their pain assessed at baseline, during, and for 10 days after SBRT using the Brief Pain Inventory. All pain medications were recorded daily and narcotics converted to an oral morphine equivalent dose. Pain flare was defined as a 2-point increase in worst pain score as compared with baseline with no decrease in analgesic intake, a 25% increase in analgesic intake as compared with baseline with no decrease in worst pain score, or if corticosteroids were initiated at any point during or after SBRT because of pain. RESULTS: The median age and Karnofsky performance status were 57.5 years (range, 27-80 years) and 80 (range, 50-100), respectively. Eighteen patients were treated with 20-24 Gy in a single fraction, whereas 23 patients were treated with 24-35 Gy in 2-5 fractions. Pain flare was observed in 68.3% of patients (28 of 41), most commonly on day 1 after SBRT (29%, 8 of 28). Multivariate analysis identified a higher Karnofsky performance status (P=.02) and cervical (P=.049) or lumbar (P=.02) locations as significant predictors of pain flare. In those rescued with dexamethasone, a significant decrease in pain scores over time was subsequently observed (P<.0001). CONCLUSIONS: Pain flare is a common adverse event after spine SBRT and occurs most commonly the day after treatment completion. Patients should be appropriately consented for this adverse event.


Assuntos
Analgésicos/uso terapêutico , Dexametasona/uso terapêutico , Glucocorticoides/uso terapêutico , Dor/tratamento farmacológico , Dor/fisiopatologia , Radiocirurgia/efeitos adversos , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgésicos/administração & dosagem , Dexametasona/administração & dosagem , Feminino , Glucocorticoides/administração & dosagem , Humanos , Avaliação de Estado de Karnofsky , Dor Lombar/tratamento farmacológico , Dor Lombar/etiologia , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Cervicalgia/tratamento farmacológico , Cervicalgia/etiologia , Cervicalgia/fisiopatologia , Dor/etiologia , Medição da Dor/métodos , Estudos Prospectivos , Dosagem Radioterapêutica , Neoplasias da Coluna Vertebral/secundário , Vértebras Torácicas
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