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BACKGROUND/AIM: Heterotopic ossification (HO) is a common complication following total hip arthroplasty. Various prophylactic treatments have been proposed, including radiotherapy (RT). This review summarizes the evidence from meta-analyses on the efficacy of RT in preventing hip HO. MATERIALS AND METHODS: A literature search was conducted on PubMed. The quality of the meta-analyses was assessed using the AMSTAR-2 tool. RESULTS: Seven meta-analyses were included. One meta-analysis reported a significant reduction in HO occurrence after RT compared to the control group. Comparing RT and non-steroidal anti-inflammatory drugs, one and two meta-analyses showed significantly greater efficacy of RT in preventing severe HO and better outcomes in patients receiving drugs, respectively. Regarding RT settings, the postoperative and preoperative RT were each supported by one meta-analysis. Furthermore, two meta-analyses showed an advantage of multi-fractionated RT over single fraction RT. The overall confidence rate of the meta-analyses was moderate, low, and critically low in one, three, and three meta-analyses, respectively. CONCLUSION: RT is a confirmed prophylactic intervention for HO. However, the precise optimization of timing, dosage, and fractionation requires elucidation. Future research should focus on the development of predictive models through large-scale data collection and advanced analytics to refine individualized treatment strategies and assess RT comparative effectiveness with drugs.
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Artroplastia de Quadril , Ossificação Heterotópica , Humanos , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Ossificação Heterotópica/prevenção & controle , Ossificação Heterotópica/etiologia , Ossificação Heterotópica/radioterapia , Medicina de Precisão/métodos , Radioterapia/efeitos adversos , Radioterapia/métodos , Resultado do Tratamento , Metanálise como AssuntoRESUMO
OBJECTIVES: Stereotactic body radiotherapy (SBRT) and/or single fraction stereotactic body radiosurgery (SRS) are effective treatment options for the treatment of oligometastatic disease of lymph nodes. Despite the encouraging local control rate, progression-free survival remains unfair due to relapses that might occur in the same district or at other sites. The recurrence pattern analysis after nodal local ablative RT (laRT) in oligometastatic patients is presented in this study. METHODS: The pattern of failure of patients with nodal metastases who were recruited and treated with SBRT in the Destroy-1 or SRS in the Destroy-2 trials was investigated in this single-institution, retrospective analysis. The different relapsed sites following laRT were recorded. RESULTS: Data on 190 patients who received SBRT or SRS on 269 nodal lesions were reviewed. A relapse rate of 57.2% (154 out of 269 nodal lesions) was registered. The pattern of failure was distant in 88 (57.4%) and loco-regional in 66 (42.6%) patients, respectively. The most frequent primary malignancies among patients experiencing loco-regional failure were genitourinary and gynaecological cancers. Furthermore, the predominant site of loco-regional relapse (62%) was the pelvic area. Only 26% of locoregional relapses occurred contra laterally, with 74% occurring ipsilaterally. CONCLUSIONS: The recurrence rates after laRT for nodal disease were more frequent in distant regions compared to locoregional sites. The most common scenarios for locoregional relapse appear to be genitourinary cancer and the pelvic site. In addition, recurrences often occur in the same nodal station or in a nodal station contiguous to the irradiated nodal site. ADVANCES IN KNOWLEDGE: Local ablative radiotherapy is an effective treatment in managing nodal oligometastasis. Despite the high local control rate, the progression free survival remains dismal with recurrences that can occur both loco-regionally or at distance. To understand the pattern of failure could aid the physicians to choose the best treatment strategy. This is the first study that reports the recurrence pattern of a significant number of nodal lesions treated with laRT.
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Metástase Linfática , Recidiva Local de Neoplasia , Radiocirurgia , Humanos , Radiocirurgia/métodos , Feminino , Recidiva Local de Neoplasia/radioterapia , Masculino , Estudos Retrospectivos , Metástase Linfática/radioterapia , Pessoa de Meia-Idade , Idoso , Adulto , Idoso de 80 Anos ou mais , Linfonodos/patologiaRESUMO
PURPOSE: Discriminant analysis of principal components (DAPC) was introduced to describe the clusters of genetically related individuals focusing on the variation between the groups of individuals. Borrowing this approach, we evaluated the potential of DAPC for the evaluation of clusters in terms of treatment response to SBRT of lung lesions using radiomics analysis on pre-treatment CT images. MATERIALS AND METHODS: 80 pulmonary metastases from 56 patients treated with SBRT were analyzed. Treatment response was stratified as complete, incomplete and null responses. For each lesion, 107 radiomics features were extracted using the PyRadiomics software. The concordance correlation coefficients (CCC) between the radiomics features obtained by two segmentations were calculated. DAPC analysis was performed to infer the structure of "radiomically" related lesions for treatment response assessment. The DAPC was performed using the "adegenet" package for the R software. RESULTS: The overall mean CCC was 0.97 ± 0.14. The analysis yields 14 dimensions in order to explain 95 % of the variance. DAPC was able to group the 80 lesions into the 3 different clusters based on treatment response depending on the radiomics features characteristics. The first Linear Discriminant achieved the best discrimination of individuals into the three pre-defined groups. The greater radiomics loadings who contributed the most to the treatment response differentiation were associated with the "sphericity", "correlation" and "maximal correlation coefficient" features. CONCLUSION: This study demonstrates that a DAPC analysis based on radiomics features obtained from pretreatment CT is able to provide a reliable stratification of complete, incomplete or null response of lung metastases following SBRT.
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Neoplasias Pulmonares , Análise de Componente Principal , Radiocirurgia , Humanos , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/diagnóstico por imagem , Radiocirurgia/métodos , Análise Discriminante , Resultado do Tratamento , Masculino , Feminino , Tomografia Computadorizada por Raios X , Idoso , Pessoa de Meia-Idade , Processamento de Imagem Assistida por Computador/métodos , Idoso de 80 Anos ou mais , RadiômicaRESUMO
Palliative radiotherapy (RT) effectively relieves pain in patients with bone metastases (BMs). Furthermore, several clinical trials, in most cases conducted in high-income countries (HICs), proved that single-fraction RT is equally effective compared to multi-fractionated RT. However, the evidence is scarce regarding low/middle-income countries (LMICs), where the diagnosis of BMs could be later and RT techniques less advanced. Therefore, we conducted a systematic literature review to evaluate the efficacy of palliative RT of BMs in the LMIC setting. A literature search was performed independently by two authors on the PubMed, Cochrane and Scopus databases. Overall, 333 records were screened and after the selection process, 11 papers were included in the analysis. Complete pain response rates ranged from 11.5% to 37.1% (median: 22%) for single-fraction RT and from 0% to 35.1% (median: 19%) for multi-fractionated RT. Partial pain response rates ranged from 23.1% to 76.9% (median: 53.8%) for single fraction RT and from 23.8% to 84.6% (median: 65%) for multi-fractionated RT. Four randomized trials compared single-fraction RT with multiple-fraction RT and none of them showed significant differences in terms of pain relief. Our analysis showed that pain response rates after palliative RT recorded in LMIC are like those reported in studies performed in HIC. Even in this setting, RT in single fraction shows comparable pain response rates to multifractional RT.
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Neoplasias Ósseas , Dor do Câncer , Países em Desenvolvimento , Cuidados Paliativos , Humanos , Cuidados Paliativos/métodos , Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Dor do Câncer/radioterapia , Manejo da Dor/métodos , Resultado do TratamentoRESUMO
Brachytherapy (BRT) plays a pivotal role in the treatment of tumors, offering precise radiation therapy directly to the affected area. However, this technique demands extensive training and skills development, posing challenges for widespread adoption and ensuring patient safety. This narrative review explored the utilization of augmented reality (AR) in BRT, seeking to summarize existing evidence, discuss key findings, limitations, and quality of research as well as outline future research directions. The review revealed promising findings regarding the integration of AR in BRT. Studies have suggested the feasibility and potential benefits of AR in education, training, intra-operative guidance, and treatment planning. However, the evidence remains limited and heterogeneous, with most studies in preliminary phases. Standardization, prospective clinical trials, patient-centered outcomes assessment, and cost-effectiveness analysis emerge as critical areas for future research. Augmented reality holds transformative potential for BRT by enhancing precision, safety, and training efficiency. To fully implement these benefits, the field requires standardized protocols, rigorous clinical trials, and in-depth patient-centered investigations. Policy-makers and healthcare providers should closely monitor developments in AR and consider its implementation in clinical practice, contingent and robust evidence, and cost-effectiveness analysis. The pro-active pursuit of evidence-based practices will contribute to optimizing patient care in BRT.
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BACKGROUND: The primary objective of this study was to assess the adequacy of analgesic care in radiotherapy (RT) patients, with a secondary objective to identify predictive variables associated with pain management adequacy using a modern statistical approach, integrating the Least Absolute Shrinkage and Selection Operator (LASSO) algorithm and the Classification and Regression Tree (CART) analysis. METHODS: This observational, multicenter cohort study involved 1387 patients reporting pain or taking analgesic drugs from 13 RT departments in Italy. The Pain Management Index (PMI) served as the measure for pain control adequacy, with a PMI score < 0 indicating suboptimal management. Patient demographics, clinical status, and treatment-related factors were examined to discern the predictors of pain management adequacy. RESULTS: Among the analyzed cohort, 46.1% reported inadequately managed pain. Non-cancer pain origin, breast cancer diagnosis, higher ECOG Performance Status scores, younger patient age, early assessment phase, and curative treatment intent emerged as significant determinants of negative PMI from the LASSO analysis. Notably, pain management was observed to improve as RT progressed, with a greater discrepancy between cancer (33.2% with PMI < 0) and non-cancer pain (73.1% with PMI < 0). Breast cancer patients under 70 years of age with non-cancer pain had the highest rate of negative PMI at 86.5%, highlighting a potential deficiency in managing benign pain in younger patients. CONCLUSIONS: The study underscores the dynamic nature of pain management during RT, suggesting improvements over the treatment course yet revealing specific challenges in non-cancer pain management, particularly among younger breast cancer patients. The use of advanced statistical techniques for analysis stresses the importance of a multifaceted approach to pain management, one that incorporates both cancer and non-cancer pain considerations to ensure a holistic and improved quality of oncological care.
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Locally advanced cervical cancer represents a significant treatment challenge. Body composition parameters such as body mass index, sarcopenia, and sarcopenic obesity, defined by sarcopenia and BMI ≥ 30 kg/m2, have been identified as potential prognostic factors, yet their overall impact remains underexplored. This study assessed the relationship between these anthropometric parameters alongside clinical prognostic factors on the prognosis of 173 cervical cancer patients. Survival outcomes in terms of local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were analyzed using Kaplan regression methods-Meier and Cox. Older age, lower hemoglobin levels, higher FIGO (International Federation of Gynecology and Obstetrics) stages, and lower total radiation doses were significantly associated with worse outcomes. Univariate analysis showed a significant correlation between BMI and the outcomes examined, revealing that normal-weight patients show higher survival rates, which was not confirmed by the multivariate analysis. Sarcopenia was not correlated with any of the outcomes considered, while sarcopenic obesity was identified as an independent negative predictor of DFS (HR: 5.289, 95% CI: 1.298-21.546, p = 0.020) and OS (HR: 2.645, 95% CI: 1.275-5.488, p = 0.009). This study highlights the potential of sarcopenic obesity as an independent predictor of clinical outcomes. These results support their inclusion in prognostic assessments and treatment planning for patients with advanced cervical cancer.
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PURPOSE: DESTROY-4 (DOSE-ESCALATION STUDY OF STEREOTACTIC BODY RADIATION THERAPY) was a Phase I trial aimed to evaluate the safety and the feasibility of escalating doses of stereotactic body radiation therapy (SBRT) on MRI-defined Dominant Intraprostatic Lesion (DIL) in low- and intermediate-risk pCa patients using a simultaneous integrated boost-volumetric arc therapy (SIB-VMAT) technique. METHODS: Eligible patients included those with low- and intermediate-risk prostate carcinoma (NCCN risk classes) and an International Prostatic Symptoms Score (IPSS) ≤â¯15. No restriction about DIL and prostate volumes was set. Pretreatment preparation required an enema and the placement of intraprostatic gold fiducials. SBRT was delivered in five consecutive daily fractions. For the first three patients, the DIL radiation dose was set at 8â¯Gy per fraction up to a total dose of 40â¯Gy (PTV1) and was gradually increased in succeeding cohorts to total doses of 42.5â¯Gy, 45.0â¯Gy, 47.5â¯Gy, and finally, 50.0â¯Gy, while keeping the prescription of 35â¯Gy/7â¯Gy per fraction for the entire prostate gland. Dose-limiting toxicity (DLT) was defined as grade 3 or worse gastrointestinal (GI) or genitourinary (GU) toxicity occurring within 90 days of follow-up (Common Terminology Criteria of Adverse Events scale 4.0). Patients completed quality-of-life questionnaires at defined intervals. RESULTS: Twenty-four patients with a median age of 75 (range, 58-89) years were enrolled. The median follow-up was 26.3 months (8.9-84 months). 66.7% of patients were classified as intermediate-risk groups, while the others were low-risk groups, according to the NCCN guidelines. Enrolled patients were treated as follows: 8 patients (40â¯Gy), 5 patients (42.5â¯Gy), 4 patients (45â¯Gy), 4 patients (47.5â¯Gy), and 3 patients (50â¯Gy). No severe acute toxicities were observed. G1 and G2 acute GU toxicities occurred in 4 (16%) and 3 patients (12.5%), respectively. Two patients (8.3%) and 3 patients (12.5%) experienced G1 and G2 GI toxicities, respectively. Since no DLTs were observed, 50â¯Gy in five fractions was considered the MTD. The median nadir PSA was 0.20â¯ng/mL. A slight improvement in QoL values was registered after the treatment. CONCLUSION: This trial confirms the feasibility and safety of a total SIB-VMAT dose of 35â¯Gy on the whole gland and 50â¯Gy on DIL in 5 fractions daily administered in a well-selected low- and intermediate-risk prostate carcinoma population. A phase II study is ongoing to confirm the tolerability of the schedule and assess the efficacy.
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Carcinoma , Neoplasias da Próstata , Radiocirurgia , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/patologia , Qualidade de Vida , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Fatores de RiscoRESUMO
Radiotherapy (RT) and electrochemotherapy (ECT) are established local treatments for cancer. While effective, both therapies have limitations, especially in treating bulky and poorly oxygenated tumors. ECT has emerged as a promising palliative treatment, raising interest in exploring its combination with RT to enhance tumor response. However, the potential benefits and challenges of combining these treatments remain unclear. A systematic review was conducted following PRISMA guidelines. PubMed, Scopus, and Cochrane libraries were searched. Studies were screened and selected based on predefined inclusion and exclusion criteria. Ten studies were included, comprising in vitro and in vivo experiments. Different tumor types were treated with ECT alone or in combination with RT. ECT plus RT demonstrated superior tumor response compared to that under single therapies or other combinations, regardless of the cytotoxic agent and RT dose. However, no study demonstrated a clear superadditive effect in cell survival curves, suggesting inconclusive evidence of specific ECT-induced radiosensitization. Toxicity data were limited. In conclusion, the combination of ECT and RT consistently improved tumor response compared to that with individual therapies, supporting the potential benefit of their combination. However, evidence for a specific ECT-induced radiosensitization effect is currently lacking. Additional investigations are necessary to elucidate the potential benefits of this combination therapy.
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Antineoplásicos , Eletroquimioterapia , Neoplasias , Radiossensibilizantes , Humanos , Radiossensibilizantes/farmacologia , Radiossensibilizantes/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Antineoplásicos/uso terapêutico , Cuidados PaliativosRESUMO
Locally advanced cervical cancer (LACC) is treated with concurrent chemoradiation (CRT). Predictive models could improve the outcome through treatment personalization. Several factors influence prognosis in LACC, but the role of systemic inflammation indices (IIs) is unclear. This study aims to assess the correlation between IIs and prognosis in a large patient cohort considering several clinical data. We retrospectively analyzed pretreatment IIs (NLR, PLR, MLR, SII, LLR, COP-NLR, APRI, ALRI, SIRI, and ANRI) in 173 LACC patients. Patient, tumor, and treatment characteristics were also considered. Univariate and multivariate Cox's regressions were conducted to assess associations between IIs and clinical factors with local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). Univariate analysis showed significant correlations between age, HB levels, tumor stage, FIGO stage, and CRT dose with survival outcomes. Specific pretreatment IIs (NLR, PLR, APRI, ANRI, and COP-NLR) demonstrated associations only with LC. The multivariate analysis confirmed Hb levels, CRT dose, and age as significant predictors of OS, while no II was correlated with any clinical outcome. The study findings contradict some prior research on IIs in LACC, emphasizing the need for comprehensive assessments of potential confounding variables.
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Simulators have revolutionized medical education and training across various disciplines, offering unique advantages in skill acquisition and performance improvement. In the context of interventional radiation therapy (IRT), simulators have emerged as valuable tools for training healthcare professionals in these complex procedures. This narrative review summarized the available evidence on the use of simulators in IRT training, highlighting their impact on proficiency, engagement, and self-confidence as well as their benefits for medical physicists and radiation therapists. A systematic search was conducted in PubMed, resulting in inclusion of 10 papers published since 2009, with 5 of them published since 2020. Publications originated from centers in USA, Ireland, Switzerland, Canada, and Japan, covering a range of IRT settings, including general, prostate, and cervical IRT. The review demonstrated that simulators provide a controlled and realistic environment for skill acquisition, allowing healthcare professionals to practice procedures, optimize image quality, and enhance technical proficiency. The use of simulators addressed the barriers associated with limited caseload and procedural complexity, ultimately contributing to improved education and IRT training. While cost considerations may exist, simulators offer long-term cost-effective solutions, balancing the potential benefits in improving educational outcomes and patient care. Overall, simulators play a crucial role in IRT training, enhancing the skills and competence of healthcare providers and improving access to quality IRT care worldwide. Future research should focus on evaluating the long-term impact of simulation-based training on clinical outcomes and patient satisfaction, exploring different simulation models and training approaches, and addressing region-specific barriers to optimize the utilization of IRT.
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Secondary cancer risk is a significant concern for women treated with breast radiation therapy due to improved long-term survival rates. We evaluated the potential of new advanced automated planning algorithms together with hybrid techniques to minimize the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for early staged breast cancer. Using CT data set of 25 patients, we generated 4 different radiation treatment plans of different complexity, including 3-dimensional conformal radiotherapy (3D-CRT), field-in-field (FinF), hybrid-IMRT (HMRT) and automated hybrid-VMAT (HVMAT) techniques. The organ-equivalent dose (OED) was calculated from differential dose-volume histograms on the basis of the "linear-exponential," "plateau," and "full mechanistic" dose-response models and was used to evaluate the EAR for secondary cancer in the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL). Statistical comparisons of data were performed by a Kruskal-Wallis analysis of variance. The planning objectives were fulfilled with all the planning techniques for both target coverage and organs-at-risk sparing. The differences in EAR for CB, CL and IL secondary tumor induction were not significant among the 4 techniques. For the CB and CL, the mean absolute difference did not reach 1 case of 10000 patient-years. For the IL, the mean absolute difference was up to 5 cases of 10,000 patient-years. In conclusion, the automated HVMAT technique allows an EAR reduction at the level of well-consolidated tangential 3D-CRT or FinF techniques, keeping all the HVMAT dosimetric improvements unchanged. On the basis of this analysis, the adoption of the HVMAT technique poses no increase in EAR and could be considered safe also for younger patients.
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Neoplasias da Mama , Neoplasias Induzidas por Radiação , Segunda Neoplasia Primária , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Humanos , Feminino , Neoplasias da Mama/radioterapia , Neoplasias da Mama/patologia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/efeitos adversos , Radioterapia Conformacional/métodos , Segunda Neoplasia Primária/etiologia , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Técnicas de PlanejamentoRESUMO
Systemic inflammation indices were found to be correlated with therapeutic outcome in several cancers. This study retrospectively analyzes the predictive role of a broad range of systemic inflammatory markers in patients with locally advanced cervical cancer (LACC) including patient-, tumor-, and treatment-related potential prognostic factors. All patients underwent definitive chemoradiation and pretreatment values of several inflammatory indices (neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, monocyte/lymphocyte ratio, systemic immune inflammation index (SII), leukocyte/lymphocyte ratio, combination of platelet count and NLR, aspartate aminotransferase/platelet ratio index, aspartate aminotransferase/lymphocyte ratio index, systemic inflammatory response index, and aspartate transaminase/neutrophil ratio index) were calculated. Their correlation with local control (LC), distant metastasis-free (DMFS), disease-free (DFS), and overall survival (OS) was analyzed. One hundred and seventy-three patients were included. At multivariable analysis significant correlations were recorded among clinical outcomes and older age, advanced FIGO stage, lower hemoglobin levels, larger tumor size, and higher body mass index values. The multivariate analysis showed only the significant correlation between higher SII values and lower DMFS rates (p < 0.01). Our analysis showed no significant correlation between indices and DSF or OS. Further studies are needed to clarify the role of inflammation indices as candidates for inclusion in predictive models in this clinical setting.
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Different options for locally advanced pancreatic cancer (LAPC) are available based on international guidelines: chemotherapy (CHT), chemoradiation (CRT), and stereotactic body radiotherapy (SBRT). However, the role of radiotherapy is debated in LAPC. We retrospectively compared CHT, CRT, and SBRT ± CHT in a real-world setting in terms of overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS). LAPC patients from a multicentric retrospective database were included (2005-2018). Survival curves were calculated using the Kaplan-Meier method. Multivariable Cox analysis was performed to identify predictors of LC, OS, and DMFS. Of the 419 patients included, 71.1% were treated with CRT, 15.5% with CHT, and 13.4% with SBRT. Multivariable analysis showed higher LC rates for CRT (HR: 0.56, 95%CI 0.34-0.92, p = 0.022) or SBRT (HR: 0.27, 95%CI 0.13-0.54, p < 0.001), compared to CHT. CRT (HR: 0.44, 95%CI 0.28-0.70, p < 0.001) and SBRT (HR: 0.40, 95%CI 0.22-0.74, p = 0.003) were predictors of prolonged OS with respect to CHT. No significant differences were recorded in terms of DMFS. In selected patients, the addition of radiotherapy to CHT is still an option to be considered. In patients referred for radiotherapy, CRT can be replaced by SBRT considering its duration, higher LC rate, and OS rate, which are at least comparable to that of CRT.
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Neoplasias Pancreáticas , Radiocirurgia , Humanos , Estudos Retrospectivos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/radioterapia , Pâncreas , Quimiorradioterapia , Radiocirurgia/métodosRESUMO
PURPOSE: Stereotactic body radiotherapy (SBRT) is a key treatment modality for lung cancer patients. This study aims to develop a machine learning-based prediction model of complete response for lung oligometastatic cancer patients undergoing SBRT. MATERIALS AND METHODS: CT images of 80 pulmonary oligometastases from 56 patients treated with SBRT were analyzed. The gross tumor volumes (GTV) were contoured on CT images. Patients that achieved complete response (CR) at 4 months were defined as responders. For each GTV, 107 radiomic features were extracted using the Pyradiomics software. The concordance correlation coefficients (CCC) between the region of interest (ROI)-based radiomics features obtained by the two segmentations were calculated. Pairwise feature interdependencies were evaluated using the Spearman rank correlation coefficient. The association of clinical variables and radiomics features with CR was evaluated with univariate logistic regression. Two supervised machine learning models, the logistic regression (LR) and the classification and regression tree analysis (CART), were trained to predict CR. The models were cross-validated using a five-fold cross-validation. The performance of models was assessed by receiver operating characteristic curve (ROC) and class-specific accuracy, precision, recall, and F1-measure evaluation metrics. RESULTS: Complete response was associated with four radiomics features, namely the surface to volume ratio (SVR; pâ¯= 0.003), the skewness (Skew; pâ¯= 0.027), the correlation (Corr; pâ¯= 0.024), and the grey normalized level uniformity (GNLU; pâ¯= 0.015). No significant relationship between clinical parameters and CR was found. In the validation set, the developed LR and CART machine learning models had an accuracy, precision, and recall of 0.644 and 0.750, 0.644 and 0.651, and 0.635 and 0.754, respectively. The area under the curve for CR prediction was 0.707 and 0.753 for the LR and CART models, respectively. CONCLUSION: This analysis demonstrates that radiomics features obtained from pretreatment CT could predict complete response of lung oligometastases following SBRT.
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Neoplasias Pulmonares , Radiocirurgia , Humanos , Radiocirurgia/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/patologia , Pulmão/patologia , Curva ROC , Tomografia Computadorizada por Raios X/métodosRESUMO
The aim of this narrative review of the literature was to collect and analyze the results of the published preclinical studies on stereotactic arrhythmia radioablation (STAR) in the treatment of refractory cardiac arrhythmias. A literature search was conducted on PubMed using the following terms: ("stereotactic" OR "SBRT" OR "SABR" OR "radioablation" OR "radiosurgery") AND ("arrhythmia" OR "tachycardia"). Preclinical and pathological reports published in English without time limit, comprising studies of STAR in animal models and histological analyzes of explanted animal and human hearts were included. The analyzed studies confirm that doses lower than 25 Gy seem to produce sub-optimal therapeutic results whereas doses >35 Gy are less safe in terms of radiation-induced toxicity. However, long-term results (>1 year) are still missing and reporting outcomes based on low dose irradiation (≤15 Gy). Finally, STAR proved to be an effective therapy in the analyzed studies despite the irradiation of rather different cardiac targets. Therefore, additional studies are needed to: 1) compare the outcomes of STAR at doses of 25 Gy versus 30 Gy; 2) evaluate the long-term results (>1 year) in animal models irradiated at doses similar to those used in the clinic; 3) define the optimal target.
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Arritmias Cardíacas , Radiocirurgia , Animais , Humanos , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/radioterapia , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Coração , Modelos Animais , Fatores de TempoRESUMO
Significant improvements in plan quality using automated planning have been previously demonstrated. The aim of this study was to develop an optimal automated class solution for stereotactic radiotherapy (SBRT) planning of prostate cancer using the new Feasibility module implemented in the pinnacle evolution. Twelve patients were retrospectively enrolled in this planning study. Five plans were designed for each patient. Four plans were automatically generated using the 4 proposed templates for SBRT optimization implemented in the new pinnacle evolution treatment planning systems, differing for different settings of dose-fallout (low, medium, high and veryhigh). Based on the obtained results, the fifth plan (feas) was generated customizing the template with the optimal criteria obtained from the previous step and integrating in the template the "a-priori" knowledge of OARs sparing based on the Feasibility module, able to estimate the best possible dose-volume histograms of OARs before starting optimization. Prescribed dose was 35 Gy to the prostate in 5 fractions. All plans were generated with a full volumetric-modulated arc therapy arc and 6MV flattening filter-free beams, and optimized to ensure the same target coverage (95% of the prescription dose to 98% of the target). Plans were assessed according to dosimetric parameters and planning and delivery efficiency. Differences among the plans were evaluated using a Kruskal-Wallis 1-way analysis of variance. The requests for more aggressive objectives for dose falloff parameters (from low to veryhigh) translated in a statistically significant improvement of dose conformity, but at the expense of a dose homogeneity. The best automated plans in terms of best trade-off between target coverage and OARs sparing among the 4 plans automatically generated by the SBRT module were the high plans. The veryhigh plans reported a significant increase of high-doses to prostate, rectum, and bladder that was considered dosimetrically and clinically unacceptable. The feas plans were optimized on the basis on high plans, reporting significant reduction of rectum irradiation; Dmean, and V18 decreased by 19% to 23% (pâ¯=â¯0.031) and 4% to 7% (pâ¯=â¯0.059), respectively. No statistically significant differences were found in femoral heads and penile bulb irradiation for all dosimetric metrics. feas plans showed a significant increase of MU/Gy (mean: 368; pâ¯=â¯0.004), reflecting an increased level of fluence modulation. Thanks to the new efficient optimization engines implemented in pinnacle evolution (L-BFGS and layered graph), mean planning time was decreased to less than 10 minutes for all plans and all techniques. The integration of dose-volume histograms a-priori knowledge provided by the feasibility module in the automated planning process for SBRT planning has shown to significantly improve plan quality compared to generic protocol values as inputs.
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The aim of this study was to evaluate the reproducibility and stability of left breast positioning during spirometer-guided deep-inspiration breath-hold (DIBH) radiotherapy using an optical surface imaging system (AlignRT). The AlignRT optical tracking system was used to monitor five left-sided breast cancer patients treated using the Active Breathing Coordinator spirometer with DIBH technique. Treatment plans were created using an automated hybrid-VMAT technique on DIBH CTs. A prescribed dose of 60 Gy to the tumor bed and 50 Gy to the breast in 25 fractions was planned. During each treatment session, the antero-posterior (VRT), superior-inferior (LNG), and lateral (LAT) motion of patients was continuously recorded by AlignRT. The intra-breath-hold stability and the intra- and inter-fraction reproducibility were analyzed for all breath-holds and treatment fractions. The dosimetric impact of the residual motion during DIBH was evaluated from the isocenter shifts amplitudes obtained from the 50%, 90%, and 100% cumulative distribution functions of intra-fractional reproducibility. The positional variations of 590 breath-holds as measured by AlignRT were evaluated. The mean intra-breath-hold stability during DIBH was 1.0 ± 0.4 mm, 2.1 ± 1.9 mm, and 0.7 ± 0.5 mm in the VRT, LNG, and LAT directions, with a maximal value of 8.8 mm in LNG direction. Similarly, the mean intra-breath-hold reproducibility was 1.4 ± 0.8 mm, 1.7 ± 1.0 mm, and 0.8 ± 0.5 mm in the VRT, LNG, and LAT directions, with a maximal value of 4.1 mm in LNG direction. Inter-fractional reproducibility showed better reliability, with difference in breathing levels in all fractions of 0.3 mm on average. Based on tolerance limits corresponding to the 90% cumulative distribution level, gating window widths of 1 mm, 2 mm, and 5 mm in the LAT, VRT, and LNG directions were considered an appropriate choice. In conclusion, despite the use of a dedicated spirometer at constant tidal volume, a non-negligible variability of the breast surface position has been reported during breath-holds. The real-time monitoring of breast surface using surface-guided optical technology is strongly recommended.
Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Humanos , Feminino , Reprodutibilidade dos Testes , Planejamento da Radioterapia Assistida por Computador/métodos , Respiração , Suspensão da Respiração , Mama , Dosagem Radioterapêutica , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/radioterapia , Neoplasias Unilaterais da Mama/radioterapia , Coração , Órgãos em RiscoRESUMO
PURPOSE: To evaluate the pathological complete response (pCR) rate of locally advanced rectal cancer (LARC) after adaptive high-dose neoadjuvant chemoradiation (CRT) based on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG-PET/CT). METHODS: The primary endpoint was the pCR rate. Secondary endpoints were the predictive value of 18 F-FDG-PET/CT on pathological response and acute and late toxicity. All patients performed 18 F-FDG-PET/CT at baseline (PET0) and after 2 weeks during CRT (PET1). The metabolic PET parameters were calculated both at the PET0 and PET1. The total CRT dose was 45 Gy to the pelvic lymph nodes and 50 Gy to the primary tumor, corresponding mesorectum, and to metastatic lymph nodes. Furthermore, a sequential boost was delivered to a biological target volume defined by PET1 with an additional dose of 5 Gy in 2 fractions. Capecitabine (825 mg/m2 twice daily orally) was prescribed for the entire treatment duration. RESULTS: Eighteen patients (13 males, 5 females; median age 55 years [range, 41-77 years]) were enrolled in the trial. Patients underwent surgical resection at 8-9 weeks after the end of neoadjuvant CRT. No patient showed grade > 1 acute radiation-induced toxicity. Seven patients (38.8%) had TRG = 0 (complete regression), 5 (27.0%) showed TRG = 2, and 6 (33.0%) had TRG = 3. Based on the TRG results, patients were classified in two groups: TRG = 0 (pCR) and TRG = 1, 2, 3 (non pCR). Accepting p < 0.05 as the level of significance, at the Kruskal-Wallis test, the medians of baseline-MTV, interim-SUVmax, interim-SUVmean, interim-MTV, interim-TLG, and the MTV reduction were significantly different between the two groups. 18 F-FDG-PET/CT was able to predict the pCR in 77.8% of cases through compared evaluation of both baseline PET/CT and interim PET/CT. CONCLUSIONS: Our results showed that a dose escalation on a reduced target in the final phase of CRT is well tolerated and able to provide a high pCR rate.