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BACKGROUND: Primary brain rhabdomyosarcoma is a rare primary brain malignancy with few case reports. The vast majority of cases of primary brain rhabdomyosarcoma occur in pediatric patients, and immunohistochemistry can distinguish it from embryonal subtypes; however, few cases of primary brain rhabdomyosarcoma in adults have been reported in the literature. CASE PRESENTATION: We report the case of a 26-year-old White male patient who was found to have primary brain alveolar rhabdomyosarcoma after developing headaches for several months. A brain MRI revealed a mixed cystic and solid tumor along the vermis of the cerebellum. The patient underwent a gross total surgical resection, which confirmed the diagnosis of alveolar rhabdomyosarcoma. Further staging workup for another primary focus or disseminated disease yielded negative results, confirming the diagnosis of primary alveolar rhabdomyosarcoma of the brain. CONCLUSION: The standard of care for managing this rare type of brain tumor involves surgery with adjuvant chemoradiotherapy. Further studies should be conducted for a better diagnostic and therapeutic understanding.
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Neoplasias Encefálicas , Rabdomiossarcoma Alveolar , Rabdomiossarcoma Embrionário , Rabdomiossarcoma , Adulto , Humanos , Masculino , Encéfalo/patologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Imageamento por Ressonância Magnética , Rabdomiossarcoma Alveolar/diagnóstico por imagem , Rabdomiossarcoma Alveolar/terapia , Rabdomiossarcoma Embrionário/diagnósticoRESUMO
Few case reports describe metastatic prostate cancer to the thyroid cartilage. While earlier reports identified the metastatic lesions upon developing symptoms, more recent ones have detected them via prostate-specific membrane antigen positron emission tomography (PSMA PET). Herein, we report the case of a patient with metastatic castrate-resistant prostate cancer and a PSMA PET-detected lesion in the thyroid cartilage. Over the course of 2 years, he received multiple lines of chemotherapy and hormonal therapy, and his overall disease status fluctuated - some nodal and bony metastases resolved while others appeared anew. His thyroid cartilage lesion, however, slowly progressed in a consistent fashion with increasing uptake on successive PSMA PET images. Apart from mild dysphonia, the patient remained to be asymptomatic from this lesion, and no local therapies were used. To our knowledge, this is the first close follow-up of prostate cancer metastatic to the thyroid cartilage, shedding light on the course of such lesions and helping answer management-related questions, which are particularly relevant as more occult metastases are discovered in the PSMA PET era.
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Purpose: This study of internal mammary lymph node chain (IMC) irradiation in patients with left breast cancer aimed at comparing the merits of using, on one hand, a dedicated direct IMC electron field versus a wide tangent photon field covering both breast and IMC on the other. The objective was to produce guidelines allowing clinicians to readily determine the preferred method for each patient. Methods and Materials: For 19 patients with cancer of the left breast/chest wall, we produced 2 treatment plans each using a different technique: the electron technique using 2 standard opposed photon tangents covering only the breast or chest wall along with a matching adjacent electron field targeting the IMC only or the wide tangent technique using 2 opposed wide tangents covering simultaneously IMC and breast or chest wall. All plans were then optimized for acceptable target coverage. Results: For patients where the left anterior descending coronary artery (LAD) was located outside of the wide tangent fields (13 patients), the wide tangent technique resulted in lower dose to the LAD, left lung, and heart. When the LAD was inside the wide tangents (6 patients), dose was lower with the electron technique for LAD and heart. In all cases, regardless of LAD location, the wide tangent technique returned strictly superior dose homogeneity but much higher right (contralateral) breast dose. Conclusions: A flowchart was produced based on LAD location that allows the clinician to readily determine the preferred technique for each patient without having to perform and compare 2 treatment plans, thus saving valuable planning time.
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Objective.This study aims at quantifying the lifetime attributable risk of secondary fatal cancer (LARFAC) to patients receiving adjuvant radiotherapy treatment for thymoma, a neoplasm where cure rates and life expectancy are relatively high, patient age at presentation relatively low and indications for radiotherapy controversial depending on the disease stage.Approach.An anthropomorphic phantom was scanned, organs were contoured and a standard 6 MV 3DCRT treatment plan was produced for thymoma treatment. The phantom was loaded with thermoluminescent dosimeters (TLDs) and treated by linear accelerator per plan. The TLDs were subsequently read for out-of-field dose distribution while in-field dose distribution was obtained from the planning system. Sex and age-specific lifetime radiogenic cancer risk was calculated as the sum of in-field risk and out-of-field risk. The latter risk was estimated using hybrid ICRP 2007 103-BEIR VII tables of organ-specific risks based on the linear-no threshold (LNT) model and applicable at low doses, while the former using mathematical risk models applicable at high doses.Main results.The LARFAC associated with a prescribed dose of 50 Gy to target volume in 25 fractions was in the approximate range of 1%-3%. The risk was higher for young and female patients. The largest contributing organ to this risk were the lungs by far. Using the LNT model inappropriately to calculate risk at therapeutic doses (in-field) would overestimate the risk up to tenfold.Significance.The LARFAC to patient from thymoma radiotherapy was quantified taking into consideration the inapplicability of the LNT model at therapeutic doses. The risk is not negligible; the information may be relevant to patients and clinicians.
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Segunda Neoplasia Primária , Radioterapia de Intensidade Modulada , Timoma , Neoplasias do Timo , Feminino , Humanos , Imagens de Fantasmas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Timoma/radioterapia , Neoplasias do Timo/radioterapiaRESUMO
BACKGROUND: Peripheral neutrophil-lymphocyte ratio (NLR), reflecting immune-inflammation status, shows great potential for tumor progression and outcome. Pre-treatment NLR does not fully reflect the immune-inflammatory response to treatment. This study aimed to introduce the NLR trend as a new indicator and to investigate its prognostic value in patients with nasopharyngeal carcinoma receiving radiotherapy. METHODS: This retrospective study evaluated patients with nasopharyngeal carcinoma treated with radiotherapy. The NLR trend value was calculated from the fitted line gradient via the NLRs before, during (at least once), and after each patient's first radiotherapy. The Kaplan-Meier curve and log-rank test were used to calculate and compare survival outcomes of different pretreatment NLRs and NLR trends for progression-free survival, locoregional recurrence-free survival (LRFS), and overall survival at 3 and 5 years. Multivariate Cox regression analyses were performed to assess the association between the NLR trend plus 3- and 5-year overall survival. RESULTS: The study included 528 patients. A lower NLR trend predicted worse progression-free survival, LRFS, plus 3- and 5-year overall survival. Multivariate Cox regression analysis showed that the NLR trend independently predicted 3- and 5-year overall survival. Sub-group analysis showed that the prognosis of patients with a low pretreatment NLR and a high NLR trend were superior to those of other groups. CONCLUSION: The NLR trend independently predicted the prognosis of patients with nasopharyngeal carcinoma receiving radiotherapy. The NLR trend and the pretreatment NLR combination is more precise than pretreatment NLR in predicting prognosis. A high NLR trend may be evidence of a positive immune response to radiotherapy in patients with nasopharyngeal carcinoma.
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Neoplasias Nasofaríngeas , Neutrófilos , Intervalo Livre de Doença , Humanos , Linfócitos/patologia , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/patologia , Neutrófilos/patologia , Prognóstico , Estudos RetrospectivosRESUMO
Radiotherapy-related fibrosis remains one of the most challenging treatment related side effects encountered by patients with head and neck cancer. Several established and ongoing novel therapies have been studied with paucity of data in how to best treat these patients. This review aims to provide researchers and health care providers with a comprehensive review on the presentation, etiology, and therapeutic options for this serious condition.
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Surgery and radiation therapy are both commonly used in the treatment of early stage (AJCC stages T1-T2 N0-M0) oropharyngeal squamous cell carcinoma (OPSCC). Transoral robotic surgery (TORS) and intensity modulated radiation therapy (IMRT) have been reported to result in similar survival and disease control outcomes. However, their side effect profiles widely differ. Nevertheless, patients who experience the worst side effects and quality of life are the ones who receive the combination of TORS and adjuvant radiation or chemoradiation therapy. Thus, appropriate patient selection for surgery to minimize the need for multimodality therapy is key. We propose, in this paper, the use of sentinel lymph node biopsy in the node negative (N0) neck as a means that is worth exploring for selecting patients to either radiation therapy or surgery. Patients with a positive sentinel lymph node (SLN) would be better directed to upfront radiation. On the contrary, patients with a negative SLN biopsy would be more confidently directed towards TORS and neck dissection alone.
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Neoplasias Orofaríngeas/terapia , Seleção de Pacientes , Radioterapia de Intensidade Modulada/estatística & dados numéricos , Procedimentos Cirúrgicos Robóticos/estatística & dados numéricos , Biópsia de Linfonodo Sentinela/estatística & dados numéricos , Terapia Combinada , Humanos , Esvaziamento Cervical/estatística & dados numéricos , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/patologia , Orofaringe/cirurgia , Radioterapia Adjuvante , Radioterapia de Intensidade Modulada/métodos , Procedimentos Cirúrgicos Robóticos/métodosRESUMO
OBJECTIVES: Prostate cancer incidence is increasing in the Middle East (ME); however, the data of stage at the diagnosis and treatment outcomes are lacking. In developed countries, the incidence of de novo metastatic prostate cancer ranges between 4% and 14%. We hypothesized that the rates of presentation with advanced disease are significantly higher in the ME based on clinical observation. This study aims to examine the stage at the presentation of patients with prostate cancer at a large tertiary center in the ME. METHODS: After Institutional Review Board approval, we identified the patients diagnosed with prostate adenocarcinoma and presented to a tertiary care center between January 2010 and July 2015. Clinical, demographic, and pathological characteristics were abstracted. Patients with advanced disease were stratified according to tumor volume based on definitions from practice changing clinical trials. Descriptive and Kaplan-Meier survival analysis was used. RESULTS: A total of 559 patients were identified, with a median age at the diagnosis of 65 years and an age range of 39-94 years. Median prostate-specific antigen (PSA) at the presentation was 10 ng/ml, and almost a quarter of the men (23%) presented with metastatic disease. The most common site of metastasis was the bone (34/89, 38%). High-volume metastasis was present in 30.3%, 9%, and 5.2% of the cohort based on STAMPEDE, CHAARTED, and LATITUDE trial criteria, respectively. CONCLUSION: This is the first report showing the high proportion of men from ME presenting with de novo metastasis. This could be due to many factors, including the highly variable access to specialist multidisciplinary management, lack of awareness, and lack of PSA screening in the region. There is a clear need to raise the awareness about prostate cancer screening and early detection and to address the rising burden of advanced prostate cancer affecting men in the ME region.
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Introduction Stereotactic radiosurgery (SRS) delivered to arrhythmogenic foci within the heart is a promising treatment modality. We dosimetrically evaluated the radiation dose to the organs at risk of four swine that were successfully treated with linear-accelerator-based SRS for atrioventricular (AV) node ablation. Materials and methods Single-chamber pacemakers were implanted in four large white breed swine. Cardiac computed tomography simulation scans were performed to localize the AV node and organs at risk. SRS (35-40 Gy) was delivered to the AV node, and the pigs were followed up with pacemaker interrogations. One-sample t-tests were used to evaluate Dmax of great vessels, esophagus, and chest wall as compared to known normal tissue constraints as per RTOG 0631 and AAPM Task Group 101. Results All pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic and microscopic evaluation showed fibrosis in the AV node but did not reveal any changes in non-nodal cardiac tissue or vessels. The mean Dmax±SD (p-value) of the chest wall (14.7±3.3 (0.02)), esophagus (10.7±1.1 (<0.01)) superior vena cava (3.3±4.1 (<0.01)), right pulmonary artery (16.1±6.4 (<0.01)), right pulmonary vein (15.7± 5 (<0.01)), left pulmonary artery (11.1±1.7 (<0.01)) and left pulmonary vein (14.1±2.6 (<0.01)), and the inferior vena cava (33.68±1.6 (0.026)) were significantly below the normal tissue constraint cutoffs. Mean±SD (p-value) of the ascending aorta (19.4±16.1 (0.12)) was not significantly different than normal tissue constraint cutoffs. One swine model treated at 40 Gy had small area of hotspot in the ascending aorta (40.65 (0.4 cc)). Conclusion We have demonstrated in our swine models that SRS using 35-40 Gy can be done without exceeding known human normal tissue constraints to the chest wall, esophagus, and great vessels.
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Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Tomada de Decisão Clínica , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Idoso , Anticorpos Monoclonais Humanizados , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Escamosas/diagnóstico por imagem , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Terapia Neoadjuvante , Pneumonectomia , Radioterapia de Intensidade Modulada , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: To test our hypothesis that, for young children with intracranial tumors, proton radiotherapy in a high-income country does not reduce the risk of a fatal subsequent malignant neoplasm (SMN) compared with photon radiotherapy in low- and middle-income countries. MATERIALS AND METHODS: We retrospectively selected 9 pediatric patients with low-grade brain tumors who were treated with 3-dimensional conformal radiation therapy in low- and middle-income countries. Images and contours were deidentified and transferred to a high-income country proton therapy center. Clinically commissioned treatment planning systems of each academic hospital were used to calculate absorbed dose from the therapeutic fields. After fusing supplemental computational phantoms to the patients' anatomies, models from the literature were applied to calculate stray radiation doses. Equivalent doses were determined in organs and tissues at risk of SMNs, and the lifetime attributable risk of SMN mortality (LAR) was predicted using a dose-effect model. Our hypothesis test was based on the average of the ratios of LARs from proton therapy to that of photon therapy ()(H0: = 1; H A : < 1). RESULTS: Proton therapy reduced the equivalent dose in organs at risk for SMNs and LARs compared with photon therapy for which the for the cohort was 0.69 ± 0.10, resulting in the rejection of H0 (P < .001, α = 0.05). We observed that the younger children in the cohort (2-4 years old) were at a factor of approximately 2.5 higher LAR compared with the older children (8-12 years old). CONCLUSION: Our findings suggest that proton radiotherapy has the strong potential of reducing the risk of fatal SMNs in pediatric patients with intracranial tumors if it were made available globally.
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Papillary tumors of the pineal region (PTPR) can be observed among adults with poor prognosis and high recurrence rates. Standards of therapy involve total surgical excision along with radiation therapy, with no promising prospects for primary adjuvant chemotherapy, as long-term treatment options have not been explored. Chromosome 10 loss is characteristic of PTPR, and PTEN gene alterations are frequently encountered in a wide range of human cancers and may be treated with mTORC1 inhibitors such as everolimus. In parallel, there are no reports of treating PTPR with everolimus alone as a monopharmacotherapy. We report the case of a patient diagnosed with PTPR (grade III) characterized by a PTEN R130Q alteration with chromosome 10 loss that was treated with everolimus pharmacotherapy alone, resulting in an asymptomatic course and tumor regression, a rare yet notable phenomenon not described in the literature so far with potential to alter the management approach to patients with PTPR.
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Neoplasias Encefálicas , Glândula Pineal , Pinealoma , Adulto , Cromossomos Humanos Par 10 , Everolimo/uso terapêutico , Humanos , Recidiva Local de Neoplasia , PTEN Fosfo-Hidrolase/genéticaRESUMO
Multiple randomized studies have shown that combination of chemotherapy and immune checkpoint inhibitors (ICIs) leads to better response rates and survival as compared to chemotherapy alone in the advanced stage of NSCLC. Data suggesting a benefit to using ICIs in the neoadjuvant therapy of patients with early stage NSCLC are emerging. Eligible subjects were treatment naïve patients with stage IB, II, and resectable IIIA NSCLC. Patients received three cycles of neoadjuvant chemotherapy with four doses of avelumab every 2 weeks. Patients with squamous cell cancer received cisplatin or carboplatin on day 1 and gemcitabine on days 1 and 8 of each cycle of chemotherapy. Patients with nonsquamous histology received cisplatin or carboplatin with pemetrexed on day 1 of each cycle. Patients then proceeded to their planned surgery. Out of 15 patients accrued as part of stage 1 of the study, four had a radiologic response (1 complete response), lower than the minimum of six responses needed to continue to phase 2 of the study. The study was therefore terminated. Majority had adenocarcinoma histology and stage IIIA disease. The treatment was well tolerated with no unexpected side effects. Four patients (26.7%) had grade III/IV CTCAE toxicity. This study confirms that the preoperative administration of chemotherapy and avelumab is safe. There was no indication of increased surgical complications. The benefit of adding immunotherapy to chemotherapy did not appear to enhance the overall response rate of patients in the neoadjuvant setting in patients with resectable NSCLC because this study failed to meet its primary endpoint.
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Adenocarcinoma de Pulmão/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Terapia Neoadjuvante , Pneumonectomia , Adenocarcinoma de Pulmão/mortalidade , Adenocarcinoma de Pulmão/patologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/efeitos adversos , Terapia Neoadjuvante/mortalidade , Estadiamento de Neoplasias , Pneumonectomia/efeitos adversos , Pneumonectomia/mortalidade , Intervalo Livre de Progressão , Fatores de TempoRESUMO
BACKGROUND: We report outcomes for patients with T2N0M0 glottic squamous cell carcinoma (SCC) treated with radiation therapy (RT). METHODS: Patients who received definitive RT for T2 glottic SCC from 2000 through 2013 were retrospectively reviewed. RESULTS: One hundred and thirteen patients were analyzed (median follow-up time 91 months; 85 patients received three-dimensional conformal radiotherapy [3D-CRT] and 28 received intensity-modulated radiation therapy [IMRT]). Fractionation was conventional (58%) or altered (42%); 20 patients (18%) received concurrent chemotherapy. Five-year local control was 83% for the 3D-CRT vs 81% for the IMRT group (P = .76). The ultimate locoregional control at 5 years was 100% for IMRT vs 91% for 3D-CRT (P = .1). The 5-year overall survival (OS) was 78% for 3D-CRT vs 81% for IMRT (P = .83). On multivariate analysis, younger age was the only independent predictor of improved OS (P = .0002). CONCLUSIONS: Oncologic and survival outcomes were excellent for patients with T2N0 glottic cancer. Patients treated with IMRT and 3D-CRT had no statistically significant differences in all investigated endpoints.
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Neoplasias de Cabeça e Pescoço , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Humanos , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapiaRESUMO
BACKGROUND: Given the paucity of data and widely variable rates that have been reported, the main objective of this study was to examine the prevalence of HPV-positivity in oropharyngeal squamous cell carcinoma (OPSCC) in Middle Eastern patients presenting to one of the region's largest tertiary care centers using polymerase chain reaction (PCR) amplification of the HPV E6/E7 oncogenes, a highly sensitive and specific method of detection. METHODS: Medical charts and archived pathological specimens were obtained for patients diagnosed with biopsy proven oropharyngeal cancer who presented to the American University of Beirut Medical Center between 1972 and 2017. DNA was extracted from paraffin-embedded specimens and tested for 30 high-risk and low-risk papilloma viruses using the PCR-based EUROarray HPV kit (EuroImmun). RESULTS: A total of 57 patients with oropharyngeal cancer were initially identified; only 34 met inclusion/exclusion criteria and were included in the present study. Most patients were males (73.5%) from Lebanon (79.4%). The most common primary tumor site was in the base of tongue (50%), followed by the tonsil (41.2%). The majority of patients (85.3%) tested positive for HPV DNA. CONCLUSION: The prevalence of HPV-positivity amongst Middle Eastern OPSCC patients, specifically those from Lebanon, may be far greater than previously thought. The Lebanese population and other neighboring Middle Eastern countries may require a more vigilant approach towards HPV detection and awareness. On an international level, further research is required to better elucidate non-classical mechanisms of HPV exposure and transmission.
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PURPOSE: Prostate cancer care in the Middle East is highly variable and access to specialist multidisciplinary management is limited. Academic tertiary referral centers offer cutting-edge diagnosis and treatment; however, in many parts of the region, patients are managed by non-specialists with limited resources. Due to many factors including lack of awareness and lack of prostate-specific antigen (PSA) screening, a high percentage of men present with locally advanced and metastatic prostate cancer at diagnosis. The aim of these recommendations is to assist clinicians in managing patients with different levels of access to diagnostic and treatment modalities. METHODS: The first Advanced Prostate Cancer Consensus Conference (APCCC) satellite meeting for the Middle East was held in Beirut, Lebanon, November 2017. During this meeting a consortium of urologists, medical oncologists, radiation oncologist and imaging specialists practicing in Lebanon, Syria, Iraq, Kuwait and Saudi Arabia voted on a selection of consensus questions. An additional workshop to formulate resource-stratified consensus recommendations was held in March 2019. RESULTS: Variations in practice based on available resources have been proposed to form resource-stratified recommendations for imaging at diagnosis, initial management of localized prostate cancer requiring therapy, treatment of castration-sensitive/naïve advanced prostate cancer and treatment of castration-resistant prostate cancer. CONCLUSION: This is the first regional consensus on prostate cancer management from the Middle East. The following recommendations will be useful to urologists and oncologists practicing in all areas with limited access to specialist multi-disciplinary teams, diagnostic modalities and treatment resources.
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Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Recursos em Saúde , Acessibilidade aos Serviços de Saúde , Prostatectomia , Neoplasias da Próstata/terapia , Radioterapia Adjuvante , Acetato de Abiraterona/uso terapêutico , Antineoplásicos/uso terapêutico , Benzamidas , Biópsia com Agulha de Grande Calibre , Neoplasias Ósseas/secundário , Neoplasias Ósseas/terapia , Docetaxel/uso terapêutico , Endossonografia , Humanos , Iraque , Calicreínas/metabolismo , Kuweit , Líbano , Excisão de Linfonodo , Imageamento por Ressonância Magnética , Masculino , Margens de Excisão , Oriente Médio , Metástase Neoplásica , Nitrilas , Feniltioidantoína/análogos & derivados , Feniltioidantoína/uso terapêutico , Tomografia por Emissão de Pósitrons , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/diagnóstico , Neoplasias de Próstata Resistentes à Castração/epidemiologia , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/terapia , Risco , Terapia de Salvação , Arábia Saudita , SíriaRESUMO
Stereotactic body radiotherapy uses the principle of 3-dimensional localization of a target to deliver a high dose of radiation to a precise location. The aim of this technique is to ablate tissue noninvasively. Because of its high precision and target conformity, it can deliver a high dose of radiation to a specific area in a tissue without significantly affecting nearby tissues. It is being actively studied and even used in therapy for atrial fibrillation and ventricular tachycardia.
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Arritmias Cardíacas , Radiocirurgia , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/cirurgia , HumanosRESUMO
Introduction: This study explores the feasibility of SRS/SRT treatment with MLC leaves wider than 2.5 mm at isocenter by inter-comparing treatment plans produced with 2.5, 5.0, and 10.0 mm leaves for various target sizes and shapes. Materials and methods: Forty previously treated patients were re-planned using 2.5, 5.0, and 10.0 mm wide MLC leaves. For each patient, all three plans were evaluated and contrasted between them in terms of five metrics: target dose homogeneity, conformity index, organs at risk dose, dose fall off outside the target, and dose to normal tissues. A regularity index RI was introduced that quantified the degree of target shape irregularity. The effect of target size and shape irregularity on feasibility of 5.0 and 10.0 mm leaves was analyzed. Results: Consistent plan degradation was observed for 10.0 mm (sometimes for 5.0 mm) compared to 2.5 mm MLC in terms of the above five plan metrics, but this degradation was small to clinically insignificant. As an exception, when target (PTV) size was smaller than about 1 cm diameter, clinically significant differences were found between 2.5, 5.0, and 10.0 mm MLC. Conclusion: 5.0 and 10.0 mm MLC can be used in SRS/SRT for targets (PTV) diameter larger than 1 cm. For smaller targets, 2.5 mm MLC is clinically superior, 5.0 is acceptable and 10.0 mm MLC is discouraged in terms of PTV dose conformity.
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Head and neck neuroendocrine tumors (NET) are a rare type of cancer. NET can be classified according to the histopathological features. The typical carcinoid tumor is a well-differentiated tumor that is the least common among other types. Owing to its indolent behavior and variable radiological and pathological features, treatment of carcinoid tumors remains a challenge. We report a case of a 54-year-old man presenting with a non-operable carcinoid tumor arising in the sphenoid sinuses treated with radiotherapy with stable disease control after three years follow-up.
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Purpose: The purpose of this study was to evaluate patient-related non-dosimetric predictors of cardiac sparing with the use of deep inspiration breath-hold (DIBH) in patients with left-sided breast cancer undergoing irradiation (RT). Materials and Methods: We retrospectively reviewed charts and treatment plans of one-hundred and three patients with left-sided breast cancer. All patients had both free-breathing (FB) and DIBH (with body surface tracking) plans available. (MHD) and V4 (heart volume receiving at least 4 Gy) were extracted from dose volume histograms. Fisher's exact and Chi-square tests were used to identify predictors of reductions in MHD and V4 after DIBH. Results: One-hundred and three patients were identified and most underwent mastectomy. MHD and V4 decreased significantly in DIBH plans (0.74 ± 0.25 Gy vs. 1.72 ± 0.98 Gy, p < 0.0001 for MHD; 4 ± 4.98 cc vs. 20.79 ± 18.2 cc, p < 0.0001 for V4). Body mass index (BMI), smoking and timing of CT simulation (spring/winter vs. summer/fall) were significant predictors of reduction in MHD whereas BMI, field size, chemotherapy, axillary dissection, and timing of CT simulation predicted reduction in V4. On multivariate analysis, BMI, and timing of CT simulation remained significant predictors of the heart-sparing effect of DIBH. Conclusions: In the setting of limited resources, identifying patients who will benefit the most from DIBH is extremely important. Prior studies have identified multiple dosimetric predictors of cardiac sparing and hereby we identified new non-dosimetric factors such as BMI and timing of treatments.