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BACKGROUND: The CyberKnife system features a robotically-positioned linear accelerator to deliver real-time image-guided stereotactic ablative body radiotherapy (SABR). It achieves steep dose gradients using irradiation from hundreds of different directions and increases the central dose of the gross tumor volume (GTV) without increasing the marginal dose to the planning target volume. We evaluated the effectiveness and safety of SABR with a central high dose using CyberKnife for metastatic lung tumors. METHODS: A total of 73 patients with 112 metastatic lung tumors treated with CyberKnife were retrospectively analyzed. Local control, progression-free survival, and overall survival were calculated using the Kaplan-Meier method. The median age was 69.2 years. The most common primary sites were the uterus (n = 34), colorectum (n = 24), head and neck (n = 17), and esophagus (n = 16). For peripheral lung tumors, the median radiation dose was 52 Gy in 4 fractions, whereas for centrally located lung tumors, it was 60 Gy in 8-10 fractions. The dose prescription was defined as 99% of the solid tumor components of the GTV. The median maximum dose within the GTV was 61.0 Gy. The GTV and planning target volume were enclosed conformally by the 80% and 70% isodose lines of the maximum dose, respectively. The median follow-up period was extended to 24.7 months; it was 33.0 months for survivors. RESULTS: The 2-year local control, progression-free survival, and overall survival rates were 89.1%, 37.1%, and 71.3%, respectively. Toxicities of grade ≥ 2 were noted as grade 2 and 3 radiation pneumonitis in one patient each. The two patients with grade 2 or higher radiation pneumonitis had both received simultaneous irradiation at two or three metastatic lung tumor sites. No toxicity of grade ≥ 2 was observed in patients with metastasis in one lung only. CONCLUSIONS: SABR with a central high dose using CyberKnife for metastatic lung tumors is effective with acceptable toxicity. TRIAL REGISTRATION: Number: 20557, Name: Stereotactic ablative radiotherapy using CyberKnife for metastatic lung tumor, URL: http://www.radonc.med.osaka-u.ac.jp/pdf/SBRT.pdf , Date of registration: April 1, 2021 (retrospectively registered), Date of enrollment: May 1, 2014.
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Neoplasias Pulmonares , Pneumonite por Radiação , Radiocirurgia , Feminino , Humanos , Idoso , Neoplasias Pulmonares/radioterapia , Radiocirurgia/efeitos adversos , Pescoço , PulmãoRESUMO
BACKGROUND: This dose-escalation study evaluated the toxicity and efficacy of different stereotactic body radiation therapy (SBRT) doses for selecting an optimal dose for prostatic adenocarcinoma (PCa). MATERIALS AND METHODS: This clinical trial was registered at UMIN (UMIN000014328). Patients with low- or intermediate-risk PCa were equally assigned to 3 SBRT dose levels: 35, 37.5, and 40 Gy per 5 fractions. The primary endpoint was the occurrence rate of late grade ≥2 genitourinary (GU) and gastrointestinal (GI) adverse events at 2 years, while the secondary endpoint was the 2-year biochemical relapse-free (bRF) rate. Adverse events were evaluated using the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Seventy-five patients (median age, 70 years) were enrolled from March 2014 to January 2018, of whom 10 (15%) and 65 (85%) had low- and intermediate-risk PCa, respectively. The median follow-up time was 48 months. Twelve (16%) patients received neoadjuvant androgen deprivation therapy. The 2-year occurrence rates of grade 2 late GU and GI toxicities were 34 and 7% in all cohorts, respectively (35 Gy: 21 and 4%; 37.5 Gy: 40 and 14%; 40 Gy: 42 and 5%). The occurrence risk of GU toxicities significantly increased with dose escalation (p = 0.0256). Grades 2 and 3 acute GU toxicities were observed in 19 (25%) and 1 (1%), respectively. Grade 2 acute GI toxicity was observed in 8 (11%) patients. No grade ≥3 GI or ≥4 GU acute toxicity or grade ≥3 late toxicity was observed. Clinical recurrence was detected in 2 patients. CONCLUSIONS: An SBRT dose of 35 Gy per 5 fractions is less likely to cause adverse events in patients with PCa than 375- and 40-Gy SBRT doses. Higher doses of SBRT should be applied with caution.
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Gastroenteropatias , Neoplasias da Próstata , Radiocirurgia , Masculino , Humanos , Idoso , Neoplasias da Próstata/patologia , Antígeno Prostático Específico , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Antagonistas de Androgênios/efeitos adversos , Recidiva Local de Neoplasia/radioterapia , Gastroenteropatias/epidemiologia , Gastroenteropatias/etiologiaRESUMO
PURPOSE: This study introduced an A-mode portable ultrasound bladder scanner, the Lilium® α-200 (here after Lilium; Lilium Otsuka, Kanagawa, Japan), for the treatment of prostate cancer patients with hypofractionated volumetric modulated arc therapy to improve the reproducibility of bladder volume (BV). MATERIALS AND METHODS: Thirty patients were advised to maintain full BV prior to computed tomography (CT) simulation and daily treatment. Among these, the BV of 15 patients was measured using Lilium until a BV of 80% in the simulation was achieved (with the Lilium group). Daily cone-beam CT (CBCT) was performed for treatment. The correlation between BV measured by CBCT and Lilium was assessed. The differences in the BV and dosimetric parameters of the bladder in the CBCT versus planning CT were compared between the groups with and without Lilium. RESULTS: There was a significantly strong relationship (r = 0.796, p < 0.05) between the BVs measured using CBCT and Lilium. The relative BV ratios to simulation CT < 0.5 and > 2 were observed in 10.3% and 12.7%, respectively, of treatment sessions without Lilium group, while these ratios were 1% and 2.8%, respectively, in the Lilium group. The mean absolute difference in the range of V30Gy to V40Gy without Lilium sessions was significantly larger (p < 0.05) than that in the Lilium group. CONCLUSION: The use of the A-mode portable ultrasound bladder scanner significantly improved the reproducibility of the BV, resulting in few variations in the dosimetric parameters for the bladder.
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Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada/métodos , Reprodutibilidade dos Testes , Ultrassonografia , Bexiga Urinária/diagnóstico por imagemRESUMO
BACKGROUND: Previous studies reported that cigarette smoking during radiation therapy was associated with unfavorable outcomes in various cancers using medical interviewing or monitoring of cotinine. Here, we evaluated the effect of smoking cessation on definitive radiation therapy for early stage glottic carcinoma by monitoring expiratory carbon monoxide (CO). MATERIAL AND METHODS: We enrolled 103 patients with early glottic carcinoma (T1N0/T2N0 = 79/24) who underwent conventional radiotherapy between 2005 and 2016. The median age was 70 years. Pathologically, all patients had squamous cell carcinoma. Since 2009, we confirmed smoking cessation before radiation therapy by medical interviews. Since 2014, we measured expiratory CO to strictly monitor smoking cessation. The patients were divided according to diagnosis years: 'no cessation' (2005-2008), 'incomplete cessation' (2009-2013), and 'complete cessation' (2014-2016). We retrospectively analyzed the local recurrence rate and disease-free survival (DFS). RESULTS: The median follow-up period was 60.1 months (range, 1.9-110.0 months). The 2-year local recurrence rate in the 'complete cessation' group was 5.3% and tended to be lower than that in the 'incomplete cessation' group (13.7%) and 'no cessation' group (21.2%). Multivariate analysis revealed that 'no cessation' was a risk factor for DFS (hazard ratio [HR] = 4.25) and local recurrence rate (HR = 16.5, p < .05) compared to 'complete cessation.' DISCUSSION: We confirmed that the 'complete cessation' group had better prognosis than the 'no cessation' group by monitoring expiratory CO during radiation therapy for early stage glottic carcinoma. Moreover, monitoring expiratory CO was easier and more suitable than conventional methods for evaluating smoking cessation because it provided real-time measurements.
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Carcinoma de Células Escamosas , Neoplasias Laríngeas , Abandono do Hábito de Fumar , Monóxido de Carbono , Carcinoma de Células Escamosas/patologia , Glote , Humanos , Neoplasias Laríngeas/patologia , Neoplasias Laríngeas/radioterapia , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , FumarRESUMO
BACKGROUND: Fractionated stereotactic radiosurgery (fSRS) is an important treatment strategy for unresected brain metastases. We previously reported that a good volumetric response 6 months after fSRS can be the first step for local control. Few studies have reported the association between gross tumor volume (GTV) dose, volumetric response, and local control in patients treated with the same number of fractions. Therefore, in this study, we aimed to investigate the GTV dose and volumetric response 6 months after fSRS in five daily fractions and identify the predictive GTV dose for local failure (LF) for unresected brain metastasis. METHODS: This retrospective study included 115 patients with 241 unresected brain metastases treated using fSRS in five daily fractions at our hospital between January 2013 and April 2022. The median prescription dose was 35 Gy (range, 30-35 Gy) in five fractions. The median follow-up time after fSRS was 16 months (range, 7-66 months). RESULTS: GTV D80 > 42 Gy and GTV D98 > 39 Gy were prognostic factors for over 65% volume reduction (odds ratio, 3.68, p < 0.01; odds ratio, 4.68, p < 0.01, respectively). GTV D80 > 42 Gy was also a prognostic factor for LF (hazard ratio, 0.37; p = 0.01). CONCLUSIONS: GTV D80 > 42 Gy in five fractions led to better volume reduction and local control. The goal of planning an inhomogeneous dose distribution for fSRS in brain metastases may be to increase the GTV D80 and GTV D98. Further studies on inhomogeneous dose distributions are required.
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Neoplasias Encefálicas , Fracionamento da Dose de Radiação , Radiocirurgia , Carga Tumoral , Humanos , Radiocirurgia/métodos , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Adulto , Idoso de 80 Anos ou mais , Prognóstico , Adulto Jovem , Dosagem RadioterapêuticaRESUMO
Purpose: Radiation therapy is widely used to treat head and neck squamous cell carcinoma (HNSCC). This study evaluated the association between circulating plasma programmed death-ligand 1 (PD-L1) and the outcomes of patients with HNSCC after radiation therapy. Methods and Materials: In this retrospective observational study, plasma samples of 76 patients with HNSCC who underwent radiation therapy from June 2019 to August 2021 were analyzed. These plasma samples were obtained before radiation therapy. The median follow-up was 32.5 months. Total and exosomal PD-L1 was measured by enzyme-linked immunosorbent assay and retrospectively analyzed for association with overall survival (OS), progression-free survival (PFS), and local control (LC). Prognostic factors among patients' characteristics and circulating PD-L1 in plasma were evaluated by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses. Results: The median concentration of total PD-L1 in plasma was 115.1 pg/mL (95% CI, 114.7-137.9 pg/mL), and the median concentration of exosomal PD-L1 was 2.8 pg/mL (95% CI, 6.0-13.0 pg/mL). Univariate and multivariate analyses showed exosomal PD-L1 as a prognostic factor for PFS and LC. Patients with high exosomal PD-L1 in plasma had poor PFS and LC compared with those with low exosomal PD-L1, indicating that 1-year PFS was 79.2% versus 33.3% (P < .001) and 1-year LC was 87.3% versus 50.0% (P < .001) in patients with high and low exosomal PD-L1, respectively. However, exosomal PD-L1 in plasma had no significant effect on OS. Total PD-L1 in plasma did not correlate with PFS, LC, and OS. Conclusions: The pretreatment circulating exosomal PD-L1 in plasma of patients with HNSCC was a prognostic factor after radiation therapy.
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BACKGROUND: Data on acute toxicities after stereotactic radiotherapy (SRT) for brain metastases, including multiple and large lesions, are lacking. We aimed to evaluate the incidence and nature of toxicities immediately after SRT using a linear accelerator. METHODS: This retrospective study reviewed the medical records of 315 patients with brain metastases treated with SRT at our institution between May 2019 and February 2022. In total, 439 SRT sessions were performed for 2161 brain metastases. The outcome of interest was immediate side effects (ISEs), defined as new or worsening symptoms occurring during SRT or within 14 days after the end of SRT. RESULTS: Grade ≥ 2 and ≥ 3 ISEs occurred in 16 (3.6%) and 7 (1.6%) cases, respectively. Among 63 treatments for 10 or more lesions (range: 10-40), 1 (1.6%) ISE occurred. Among 22 treatments for lesions with a maximum tumor volume of > 10 cc, 2 (9.1%) ISEs occurred. Grade ≥ 3 ISEs included 1, 4, 1, and 1 cases of grade 3 nausea, grade 3 new-onset partial and generalized seizures, grade 3 obstructive hydrocephalus, and grade 5 intracranial hemorrhage, respectively. ISEs were more common in patients with a larger maximum tumor volume, primary sites other than lung and breast cancer, and pre-treatment neurological symptoms. CONCLUSION: SRT using a linear accelerator for brain metastases, including multiple and large lesions, is safe, with a low incidence of ISEs. Serious complications immediately after SRT are rare but possible; therefore, careful follow-up is necessary after treatment initiation.
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Neoplasias Encefálicas , Radiocirurgia , Humanos , Estudos Retrospectivos , Incidência , Neoplasias Encefálicas/secundário , Radiocirurgia/efeitos adversos , Aceleradores de PartículasRESUMO
PURPOSE: In this study, we developed in-house software to evaluate the effect of the lead block (LB)-inserted spacer on the mandibular dose in interstitial brachytherapy (ISBT) for tongue cancer. In addition, an inverse planning algorithm for LB attenuation was developed, and its performance in mandibular dose reduction was evaluated. METHODS: Treatment plans of 30 patients with tongue cancer treated with ISBT were evaluated. The prescribed dose was 54 Gy/9 fractions. An in-house software was developed to calculate the dose distribution based on the American Association of Physicists in Medicine (AAPM) Task Group No.43 (TG-43) formalism. The mandibular dose was calculated with consideration of the LB attenuation. The attenuation coefficient of the lead was computed using the PHITS Monte Carlo simulation. The software further optimized the treatment plans using an attraction-repulsion model (ARM) to account for the LB attenuation. RESULTS: Compared to the calculation in water, the D2 cc of the mandible changed by - 2.4 ± 2.3 Gy (range, - 8.6 to - 0.1 Gy) when the LB attenuation was considered. The ARM optimization with consideration of the LB resulted in a - 2.4 ± 2.4 Gy (range, - 8.2 to 0.0 Gy) change in mandibular D2 cc. CONCLUSIONS: This study enabled the evaluation of the dose distribution with consideration of the LB attenuation. The ARM optimization with lead attenuation further reduced the mandibular dose.
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Braquiterapia , Neoplasias da Língua , Humanos , Neoplasias da Língua/radioterapia , Dosagem Radioterapêutica , Software , Método de Monte Carlo , Mandíbula , Planejamento da Radioterapia Assistida por ComputadorRESUMO
BACKGROUND/AIM: This study evaluated the effects of the respiratory phase shifts between liver tumor and chest wall motions on the dose distribution for the CyberKnife Synchrony respiratory tracking system (SRTS). PATIENTS AND METHODS: Eight patients who received stereotactic body radiotherapy for hepatocellular carcinoma or liver metastases were analyzed. Three-dimensional (3D) motion of the implanted fiducial markers and vertical motion of the sternal bone were derived from the four-dimensional computed tomography (4D-CT) images acquired with a 320-row area detector CT. For each patient, Gaussian random numbers were generated for the standard deviation of the tracking error calculated from the phase shift and a literature. For each voxel of the target, the dose delivered from each beam was calculated 100 times with the random 3D offsets representing the tracking error. RESULTS: The median respiratory phase shifts were 6.0% and 4.6% for the anterior-posterior (AP) and superior-inferior (SI) directions, respectively. The median motion tracking errors influenced by respiratory phase shifts were 1.21 mm and 0.96 mm for the AP and SI directions, respectively. The change in the dose covering 90% of the target (D90%) was within 1.1% when median phase shifts were considered. When evaluating the 90th percentile of the phase shifts, the D90% decreased up to 6.6%. CONCLUSION: We have developed a technique to estimate the impact of the respiratory phase shifts on the dose distribution of a liver tumor treated with the SRTS. The calculation of the respiratory phase shifts from the area-detector 4D-CT will be valuable to improve the tracking accuracy of the SRTS.
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Neoplasias Hepáticas , Radiocirurgia , Humanos , Tomografia Computadorizada Quadridimensional/métodos , Radiocirurgia/métodos , Marcadores Fiduciais , Movimento (Física) , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/cirurgiaRESUMO
BACKGROUND AND PURPOSE: Few reports include volumetric measurements as endpoints after stereotactic radiotherapy (SRT) despite the importance of such measurements. This study aimed to (1) investigate the impact of the volumetric response (specifically, an over 65% and over 90% volume reduction in brain metastases) at 6 months post-SRT on local control and (2) identify the predictive factors for a volumetric response of over 65% and over 90%. MATERIALS AND METHODS: This study included 250 unresected brain metastases (>0.3 cc) treated with SRT. Doses were stratified according to the biological effective dose (BED). The BED was calculated using four models: linear-quadratic (LQ): α/ß = 10; LQ: α/ß = 20; LQ cubic: α/ß = 12; and LQ linear: α/ß = 10. The median prescription dose was 30 Gy/3 fractions (BED20, 45). The median follow-up time after SRT was 18.6 months (range, 6.4-81.8 months). RESULTS: In the multivariate analysis, over 65% volume reduction and over 90% volume reduction were prognostic factors for local control (hazard ratio: 2.370, p = 0.011 and hazard ratio: 3.161, p = 0.014, respectively). A dose of 80% of the gross tumor volume (GTV) D80 > BED20 58 was a predictive factor for over 65% and over 90% volume reductions (odds ratio: 1.975, p = 0.023; odds ratio: 3.204, p < 0.001, respectively). CONCLUSION: Robust volume reduction of brain metastases at 6 months post-SRT can predict local control. GTV D80 in the LQ model: α/ß = 20 may be warranted for good volume reduction.
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Neoplasias Encefálicas , Radiocirurgia , Humanos , Prognóstico , Radiocirurgia/efeitos adversos , Neoplasias Encefálicas/patologia , Modelos de Riscos Proporcionais , Análise Multivariada , Estudos Retrospectivos , Dosagem RadioterapêuticaRESUMO
BACKGROUND/AIM: We evaluated the effectiveness and safety of stereotactic ablative radiotherapy (SABR) delivered using Cyberknife in patients with stage I non-small-cell lung cancer. PATIENTS AND METHODS: The clinical results of 153 patients with 161 lung cancers treated with CyberKnife between May 2014 and August 2020 at the Osaka University Hospital were retrospectively analyzed. The median age was 80 years (range=48-99 years). Nine patients (5.6%) had interstitial pneumonia. The median radiation dose was 52 Gy (range=40-70 Gy) in 4-10 fractions, and the median follow-up extended to 21.4 months (range=0-68.9 months). RESULTS: The 2-year local control, progression-free, and overall survival rates were 91.9%, 61.7%, and 84.8%, respectively. Toxicities of grade ≥3 were observed in 13 (8.1%) patients; one patient with interstitial pneumonia developed grade 5 radiation pneumonitis and one patient developed grade 5 bronchopulmonary hemorrhage. CONCLUSION: In patients with stage I non-small-cell lung cancer, SABR using Cyberknife was effective with acceptable toxicity.
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Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Radiocirurgia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Estudos RetrospectivosRESUMO
Purpose: The radiation recall phenomenon (RRP) is a rare and unexpected late complication of radiation therapy (RT). Although predominantly in the skin, RRP of the upper respiratory tract has also been reported. In general, RRP is caused by anticancer agents, and the COVID-19 vaccine has also been reported to cause RRP in recent years. Methods and Materials: A 50-year-old woman who had received RT around the larynx 3 years prior and was receiving a docetaxel + ramucirumab (RAM) regimen experienced recurrent sore throat. The administration of RAM was discontinued after a gastroscopic examination revealed mucosal bleeding from around the larynx, which was thought to be RRP caused by RAM, a vascular endothelial growth factor inhibitor. Results: After the remission of the RRP, the patient received a COVID-19 vaccine (Pfizer-BioNTech). Five days later, the appearance of cough and recurrence of sore throat worsened with time, and marked stridor was observed. The patient was admitted, and steroid pulse therapy was administered for 3 days starting on day 18 after vaccination. On day 50 after vaccination, edema of the vocal cords improved. Conclusions: When administering COVID-19 vaccines, considering that these vaccines may cause RRP is important, because RRP can be fatal in patients with a history of RT in the laryngeal region and treated with vascular endothelial growth factor inhibitors.
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BACKGROUND/AIM: This study aimed to evaluate the treatment outcomes of radiation therapy (RT) for localized prostate cancer in elderly patients aged ≥75 years. PATIENTS AND METHODS: We retrospectively investigated data of patients aged ≥75 years with prostate cancer who underwent intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) with doses of 70-78 Gy in 35-39 fractions between September 2008 and June 2016. Overall survival (OS), recurrence-free (RF) rates, and occurrence rates of toxicities were calculated. RESULTS: Eighty-eight patients were enrolled in the study. Nineteen patients died, and nine patients reported PSA failure within the follow-up period. The median follow-up time was 83.5 months. The median age was 77 years. In the cohort, 6 were low-risk, 36 were intermediaterisk, and 46 were high-risk patients. The 5-/7-year OS and RF rates were 87.9%/80.2% and 93.5%/89.1%, respectively. By risk, the 5-/7-year RF rates were 100%/80% in the low-, 100%/100% in the intermediate-, and 87.6%/82.7% in the high-risk groups, respectively. The cumulative incidence rates of Grade ≥3 genitourinary and gastrointestinal toxicities were 1.3% and 3.5% at 5 years and 3.3% and 3.5% at 7 years, respectively. CONCLUSION: IMRT and VMAT are effective treatment options for elderly patients with prostate cancer and in a good general condition.
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Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Idoso , Humanos , Masculino , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/efeitos adversos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Previous studies have reported conflicting results for the effect of overall treatment time with stereotactic body radiotherapy on tumor control in early-stage non-small-cell lung cancer. To examine this effect, we conducted a propensity score-weighted, retrospective, observational study at a single institution. We analyzed the data of 200 patients with early-stage non-small-cell lung cancer who underwent stereotactic body radiotherapy (48 Gy in 4 fractions) at our institution between January 2007 and October 2013. Patients were grouped into consecutive (overall treatment time = 4-5 days, n = 116) or non-consecutive treatment groups (overall treatment time = 6-10 days, n = 84). The outcomes of interest were local control and overall survival. The Cox regression model was used with propensity score and inverse probability of treatment weighting. The median overall treatment times in the consecutive and non-consecutive groups were 4 and 6 days, respectively. The 5-year local control and overall survival rates in the consecutive vs. the non-consecutive group were 86.3 vs. 77.2% and 55.5 vs. 51.8%, respectively. After propensity score weighting, consecutive stereotactic body radiotherapy was associated with positive local control (adjusted hazard ratio 0.30, 95% confidence interval 0.14-0.65; p = 0.002) and overall survival (adjusted hazard ratio 0.56, 95% confidence interval 0.34-0.91; p = 0.019) benefits. The prolonged overall treatment time of stereotactic body radiotherapy treatment negatively affected the outcomes of patients with early-stage non-small-cell lung cancer. To our knowledge, this is the first study to show that in patients with early-stage non-small-cell lung cancer treated with the same dose-fractionation regimen, consecutive stereotactic body radiotherapy has a more beneficial effect on tumor control than non-consecutive stereotactic body radiotherapy.
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Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Humanos , Neoplasias Pulmonares/mortalidade , Pessoa de Meia-Idade , Prognóstico , Pontuação de Propensão , Radiocirurgia , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
In this study, we evaluated the inter-unit variability of the lateral response artifact for multiple flatbed scanners, focusing on the dual-channel method, and investigated the correction method of the lateral non-uniformity. Four scanners with A3+ paper-size and five scanners with A4 paper-size were evaluated. To generate the dose-response curves, small pieces of the Gafchromic EBT3 and EBT-XD films were irradiated, and five of the pieces were repeatedly scanned by moving them on the scanner to evaluate the lateral non-uniformity. To calculate the dose distribution accounting for the lateral non-uniformity, linear functions of the correction factor, representing the difference between the pixel values at offset position and the scanner midline, were calculated for red and blue color channels at each lateral position. Large variations of the lateral non-uniformity among the scanners were observed, even for the same model of scanner. For high dose, red color showed pixel value profiles similar to symmetric curves, whereas the profiles for low dose were asymmetric. The peak positions changed with dose. With correction of the lateral non-uniformity, the dose profiles of the pyramidal dose distribution measured at various scanner positions and that calculated with a treatment planning system showed almost identical profile shapes at all high-, middle- and low-dose levels. The dual-channel method used in this study showed almost identical dose profiles measured with all A3+ and A4 paper-size scanners at any positions when the corrections were applied for each color channel.
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Artefatos , Dosimetria Fotográfica/instrumentação , Relação Dose-Resposta à Radiação , Radioterapia de Intensidade ModuladaRESUMO
PURPOSE: This study investigated the characteristics of a new shielded diode detector, microSilicon X (model 60022: MSX), for small-field and large-field dosimetry. METHODS: The percent depth dose (PDD), beam profiles, detector output factor (OFdet ), temperature dependence, dose rate dependence, dose-per-pulse (DPP) dependence, and dose-response linearity of MSX were evaluated in Cyberknife and TrueBeam photon beams and compared with various detectors including microDiamond (PTW model 60019: MD), Sun Nuclear EDGE detector, Photon diode (PTW model 60016: PD), and semiflex ionization chamber (PTW model 31010: IC). RESULTS: For field sizes ranging from 50 × 50 mm2 to 400 × 400 mm2 , MSX-measured OFdet values were within 1% of the IC-measured values. For the CyberKnife small fields, the maximum difference between the MSX-measured OFdet and the MD-measured field output factor (Ω) was 4.0%, while the maximum differences were 8.8% and 10.9% for PD and EDGE, respectively. MSX showed a stable response within 0.7% for water temperatures of 5°C to 34°C, while PD and EDGE showed a linear correlation between the water temperature and the response. MSX showed small variations within 0.2% for the dose rate, and PD and EDGE showed logarithmic increases in the response with the dose rate. MSX and MD had smaller DPP dependences than PD and EDGE. CONCLUSIONS: The characteristics of MSX for measurements of small- and large-field photon beams are favorable. Compared to PD, MSX exhibited significant improvement in the over-response for small fields. The OFdet values measured by MSX were approximately in-between those measured by MD and PD. MSX showed stable responses against water temperature, dose rate, and DPP variations and provided suitable data for a wide range of field sizes. However, careful attention is required for measurements of OFdet for field sizes of <10 × 10 mm2 and PDD for field sizes of ≥200 × 200 mm2 .
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Fótons , Radiometria , ÁguaRESUMO
To assess the objective and subjective image quality, and respiratory motion of hepatocellular carcinoma with portal vein tumor thrombosis (PVTT) using the contrast-enhanced four-dimensional dual-energy computed tomography (CE-4D-DECT). For twelve patients, the virtual monochromatic image (VMI) derived from the CE-4D-DECT with the highest contrast to noise ratio (CNR) was determined as the optimal VMI (O-VMI). To assess the objective and subjective image quality, the CNR and five-point score of the O-VMI were compared to those of the standard VMI at 77 keV (S-VMI). The respiratory motion of the PVTT and diaphragm was measured based on the exhale and inhale phase images. The VMI at 60 keV yielded the highest CNR (4.8 ± 1.4) which was significantly higher (p = 0.02) than that in the S-VMI (3.8 ± 1.2). The overall image quality (4.0 ± 0.6 vs 3.1 ± 0.5) and tumor conspicuity (3.8 ± 0.8 vs 2.8 ± 0.6) of the O-VMI determined by three radiation oncologists was significantly higher (p < 0.01) than that of the S-VMI. The diaphragm motion in the L-R (3.3 ± 2.5 vs 1.2 ± 1.1 mm), A-P (6.7 ± 4.0 vs 1.6 ± 1.3mm) and 3D (8.8 ± 3.5 vs 13.1 ± 4.9 mm) directions were significantly larger (p < 0.05) compared to the tumor motion. The improvement of objective and subjective image quality was achieved in the O-VMI. Because the respiratory motion of the diaphragm was larger than that of the PVTT, we need to be pay attention for localizing target in radiotherapy.
Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Tomografia Computadorizada Quadridimensional , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Trombose/diagnóstico por imagem , Idoso , Carcinoma Hepatocelular/complicações , Meios de Contraste/química , Diafragma/diagnóstico por imagem , Diafragma/fisiologia , Feminino , Humanos , Neoplasias Hepáticas/complicações , Masculino , Pessoa de Meia-Idade , Veia Porta/diagnóstico por imagem , Veia Porta/patologia , Estudos Retrospectivos , Razão Sinal-Ruído , Trombose/complicaçõesRESUMO
A 74-year-old man presented with recurrent syncope 3 months after definitive surgery for hypopharyngeal cancer. The patient experienced dizziness and severe hypotension on the movement of the neck and head. CT revealed disease recurrence with masses encasing the left internal carotid artery. The patient was diagnosed with vasodepressor type of tumour-induced carotid sinus syndrome (tiCSS) and was referred for palliative intensity-modulated radiotherapy (IMRT). Ten days after the commencement of IMRT (25 Gy in five fractions), the symptoms of tiCSS improved, and there was no re-exacerbation of the symptoms till the patient died 56 days after the commencement of RT. Palliative IMRT was feasible and effective for recurrent malignant tiCSS. Given the fact that palliative IMRT is minimally invasive, this option could be widely adapted for patients with such poor general condition and prognosis.
Assuntos
Carcinoma de Células Escamosas , Seio Carotídeo , Recidiva Local de Neoplasia , Neoplasias Faríngeas , Radioterapia de Intensidade Modulada/métodos , Síncope , Idoso , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Seio Carotídeo/diagnóstico por imagem , Seio Carotídeo/patologia , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/fisiopatologia , Recidiva Local de Neoplasia/radioterapia , Cuidados Paliativos/métodos , Neoplasias Faríngeas/patologia , Neoplasias Faríngeas/cirurgia , Síncope/diagnóstico , Síncope/etiologia , Síncope/fisiopatologia , Síncope/terapia , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
BACKGROUND: The present study aimed to evaluate the toxicity and efficacy of stereotactic body radiotherapy (SBRT) for localized prostate cancer. PATIENTS AND METHODS: We investigated 25 patients treated with SBRT of 35 Gy per five fractions from May 2014 to March 2015. RESULTS: The median age of patients was 70 years, four (16%) patients were low risk and 21 (84%) were intermediate risk. Seven (28%) patients received neoadjuvant androgen-deprivation therapy. The median follow-up time was 53 months. Grade 2 acute and late genitourinary toxicities were observed in five (20%) and two (8%) patients and there were no Grade 2 gastrointestinal toxicities. There were no Grade 3 or higher acute or late toxicities at 2 years follow-up. The biochemical relapse-free survival rate at 2 years was 100%. CONCLUSION: SBRT of 35 Gy per five fractions is a promising treatment method in the short term for prostate cancer.
Assuntos
Androgênios/metabolismo , Trato Gastrointestinal/efeitos dos fármacos , Neoplasias da Próstata/radioterapia , Radiocirurgia/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Androgênios/administração & dosagem , Antineoplásicos Hormonais/administração & dosagem , Fracionamento da Dose de Radiação , Trato Gastrointestinal/patologia , Humanos , Masculino , Terapia Neoadjuvante , Próstata/patologia , Próstata/efeitos da radiação , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Planejamento da Radioterapia Assistida por Computador , Medição de Risco , Resultado do TratamentoRESUMO
The prognosis of hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT) is poor. We conducted a prospective study to evaluate the efficacy and safety of tri-modality therapy, including preoperative stereotactic body radiotherapy (SBRT) and surgery, followed by hepatic arterial infusion chemotherapy (HAIC) in HCC patients with PVTT. In this report, we investigated the pathology of the irradiated PVTT specimen in resected cases and SBRT-related acute toxicity. A total of 8 HCC patients with PVTT received preoperative SBRT targeting the PVTT at a dose of 48 Gy in 4 fractions at our institute from 2012 to 2016. Of the eight patients, six underwent surgery, while the remaining two did not because of disease progression. At the pathological examination, all patients' irradiated PVTT specimens showed necrotic tissue, and three of six patients showed complete pathological response. Two patients showed 30% necrosis with high degeneration and one patient, with 30% necrosis without degeneration, was the only recurrent case found during the follow-up period (median: 22.5, range: 5.9-49.6 months). No SBRT-related acute toxicity worse than grade 2 was observed from SBRT to surgery. In conclusion, the preoperative SBRT for HCC was pathologically effective and the acute toxicities were tolerable.