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BACKGROUND: Hippocampal avoidance (HA) has been shown to preserve cognitive function in adult patients with cancer treated with whole-brain radiation therapy for brain metastases. However, the feasibility of HA in pediatric patients with brain tumors has not been explored because of concerns of increased risk of relapse in the peri-hippocampal region. Our aim was to determine patterns of recurrence and incidence of peri-hippocampal relapse in pediatric patients with medulloblastoma (MB). METHODS AND MATERIALS: We identified pediatric patients with MB treated with protons between 2002 and 2016 and who had recurrent disease. To estimate the risk of peri-hippocampal recurrence, three hippocampal zones (HZs) were delineated corresponding to ≤5 mm (HZ-1), 6 to 10 mm (HZ-2), and >10 mm (HZ-3) distance of the recurrence from the contoured hippocampi. To determine the feasibility of HA, three standard-risk patients with MB were planned using either volumetric-modulated arc therapy (VMAT) or intensity-modulated proton therapy (IMPT) plans. RESULTS: Thirty-eight patients developed a recurrence at a median of 1.6 years. Of the 25 patients who had magnetic resonance imaging of the recurrence, no patients failed within the hippocampus and only two patients failed within HZ-1. The crude incidence of peri-hippocampal failure was 8%. Both HA-VMAT and HA-IMPT plans were associated with significantly reduced mean dose to the hippocampi (p < .05). HA-VMAT and HA-IMPT plans were associated with decreased percentage of the third and lateral ventricles receiving the prescription craniospinal dose of 23.4 Gy. CONCLUSIONS: Peri-hippocampal failures are uncommon in pediatric patients with MB. Hippocampal avoidance should be evaluated in a prospective cohort of pediatric patients with MB. PLAIN LANGUAGE SUMMARY: In this study, the patterns of disease recurrence in patients with a pediatric brain tumor known as medulloblastoma treated with proton radiotherapy were examined. The majority of failures occur outside of an important structure related to memory formation called the hippocampus. Hippocampal sparing radiation plans using proton radiotherapy were generated and showed that dose to the hippocampus was able to be significantly reduced. The study provides the rationale to explore hippocampal sparing in pediatric medulloblastoma in a prospective clinical trial.
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Neoplasias Encefálicas , Neoplasias Cerebelares , Meduloblastoma , Radioterapia de Intensidade Modulada , Humanos , Criança , Meduloblastoma/radioterapia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco , Prótons , Estudos Prospectivos , Planejamento da Radioterapia Assistida por Computador/métodos , Dosagem Radioterapêutica , Irradiação Craniana/efeitos adversos , Irradiação Craniana/métodos , Recidiva Local de Neoplasia/epidemiologia , Radioterapia de Intensidade Modulada/métodos , Hipocampo/diagnóstico por imagem , Neoplasias Cerebelares/radioterapiaRESUMO
Advance care planning (ACP) enables people to discuss their physical, psychological, social, and spiritual needs before nearing death. Most literature examining the determinants of ACP engagement is limited and does not include minority faith communities in the United States, including Muslim communities. The purpose of this cross-sectional correlational study was to examine ACP engagement determinants among Muslims in the United States. Using the Social Ecological Model, we conceptualized the determinants of ACP engagement into intrapersonal, interpersonal, and community factors. The study self-administered questionnaires were distributed using convenience and snowball techniques. Multiple linear regression was used to predict ACP engagement. The total sample was 148 Muslim adults. The age range was 18 to 79 years. Among all tested factors, being Asian American, knowing a deceased person who had received aggressive or minimal medical treatments near death, being born in the United States, having knowledge and awareness about ACP, and being accepting of the American culture were the determinants of ACP engagement. Engagement in ACP is a multifactorial behavior. Several intrapersonal and interpersonal factors, but none of the community factors, were associated with ACP engagement among Muslim adults. Future ACP interventions targeted toward Muslim Americans should be planned with an understanding of the multifactorial nature of ACP engagement.
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Planejamento Antecipado de Cuidados , Islamismo , Adolescente , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Estudos Transversais , Cuidados Paliativos , Estados UnidosRESUMO
PURPOSE: Uncertainties in relative biological effectiveness (RBE) constitute a major pitfall of the use of protons in clinics. An RBE value of 1.1, which is based on cell culture and animal models, is currently used in clinical proton planning. The purpose of this study was to determine RBE for temporal lobe radiographic changes using long-term follow-up data from patients with nasopharyngeal carcinoma. METHODS AND MATERIALS: Five hundred sixty-six patients with newly diagnosed nasopharyngeal carcinoma received double-scattering proton therapy or intensity modulated radiation therapy at our institutions. The 2 treatment cohorts were well matched. Proton dose distributions were simulated using Monte Carlo and compared with those obtained from the proton clinical treatment planning system. Late treatment effect was defined as development of enhancement of temporal lobe on T1-weighted magnetic resonance imaging, with or without accompanying clinical symptoms. The tolerance dose was calculated with receiving operator characteristic analysis and the Youden index. Tolerance curves, expressed as a cumulative dose-volume histogram, were generated using the cutoff points. RESULTS: With a median follow-up period >5 years for both cohorts, 10% of proton patients and 4% of patients undergoing intensity modulated radiation therapy developed temporal lobe enhancement in unilateral temporal lobe. There was no significant difference in dose distributions between the Monte Carlo method and treatment planning system. The tolerance dose-volume levels were V10 (26.1%), V20 (21.9%), V30 (14.0%), V40 (7.7%), V50 (4.8%), and V60 (3.3%) for proton therapy (P < .03). Comparison of the two tolerance curves revealed that tolerance doses of proton treatments were lower than that of photon treatments at all dose levels. The dose tolerance at D1% was 58.56 Gy for protons and 69.07 Gy for photons. The RBE for temporal lobe enhancement from proton treatments were calculated to be 1.18. CONCLUSIONS: Using long-term clinical outcome of patients with nasopharyngeal carcinoma, our data suggest that the RBE for temporal lobe enhancement is 1.18 at D1%. A prospective study in a large cohort would be necessary to confirm these findings.
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Encéfalo/efeitos da radiação , Carcinoma Nasofaríngeo/radioterapia , Terapia com Prótons , Eficiência Biológica Relativa , Adulto , Feminino , Humanos , Masculino , Método de Monte Carlo , Estudos Prospectivos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Resultado do TratamentoRESUMO
Advance care planning (ACP) is a cornerstone of self-determination for the type of care provided at the end of life. Despite many national efforts to improve American adults' engagement in ACP, statistics indicate low engagement. Low engagement, especially among racial and ethnic minority populations, immigrants, people with lower socioeconomic status, young adults, rural residents, or non-English speakers, is common. Advance care planning engagement among Muslims living in the United States has been minimally studied. The purpose of this study was to explore Muslims' engagement in ACP. A cross-sectional descriptive design was used. Participants were recruited from Islamic organizations through convenience and snowball sampling. Engagement in ACP was measured by the Advance Care Planning Engagement Survey. A sample of 148 Muslims (18-79 years of age) participated in the study. The average engagement scores ranged from 1.97 to 2.09, with about two-thirds in the precontemplation stage. Significant differences in engagement scores were found according to health condition and end of life experiences. Results suggest a need for further collaborative efforts by health care providers, policymakers, and researchers to mitigate the disparities in ACP engagement in the American Muslim community.
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Planejamento Antecipado de Cuidados/normas , Islamismo/psicologia , Participação do Paciente/métodos , Adolescente , Adulto , Planejamento Antecipado de Cuidados/estatística & dados numéricos , Idoso , Estudos Transversais , Feminino , Humanos , Vida Independente/psicologia , Masculino , Pessoa de Meia-Idade , Participação do Paciente/psicologia , Inquéritos e Questionários , Assistência Terminal/tendências , Estados UnidosRESUMO
Chronic Hepatitis C (CHC) is the most common blood-borne infection in the U. S. Patients with CHC undergoing treatment face many challenges including adherence to medications and management of symptoms; health care practitioners are well positioned to facilitate patients' ability to address these challenges. We used the Adaptive Leadership for Chronic Illness Framework to investigate the difficulties inherent in affecting behavior change in patients undergoing treatment. We enrolled 11 patient participants and 10 provider participants. We used data from the first clinical encounter between patients and providers during which treatment was discussed. We found examples of adaptive leadership and categorized these behaviors into three themes: support for medication, coping with family/ home life, and strategizing to manage employment. We also saw examples of what we termed missed opportunities for adaptive leadership. This study illustrates the contributions of adaptive leadership behaviors by healthcare providers and the potential risk to patients in their absence.
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PURPOSE: Radiation-related toxicity in nasopharyngeal carcinoma (NPC) is common. There are no well-established guidelines for clinical target volume (CTV) delineation with long-term follow-up. Current consensus continues to rely heavily on bony landmarks and fixed margins around the gross tumor volume (GTV), an approach used to define fields in the conventional 2- and 3-dimensional radiation therapy era. METHODS AND MATERIALS: We retrospectively evaluated patients with newly diagnosed nonmetastatic NPC treated with definitive radiation therapy using a technique of CTV delineation based on individual tumor extent and the orderly stepwise pattern of tumor spread. Dosimetric comparisons were made between national protocol HN001 and our contouring strategies on a representative early- and advanced-stage NPC. The primary endpoints were patterns of failure and local control; secondary endpoints included regional control and survival, estimated using the Kaplan-Meier method. RESULTS: Between 1999 and 2013, 73 patients (88% with stage 3-4 disease) were treated with median follow-up of 90 months for surviving patients. Median dose to GTV was 70 Gy. Four patients developed local recurrence and 1 patient developed regional recurrence. All locoregional recurrences occurred within the high-dose GTV. The 5-year local control, regional control, and overall survival was 94% (95% confidence interval [CI], 85%-98%), 99% (95% CI, 90%-100%), and 84% (95% CI, 73%-91%), respectively. Compared with HN001, our contouring strategy resulted in 62% and 36% reduction in CTV for T1 and T4 disease, respectively. In the T1 tumor, the reduction of doses to the contralateral parotid, optic nerve, and cochlea were 54%, 50%, 34% respectively. In the T4 case, there was a decrease of optic chiasm dose of 46% and contralateral optic nerve of 37%. There were 10 grade 3 toxicities. There was no grade 2 or higher xerostomia and no grade 4/5 toxicity. CONCLUSIONS: Our long-term experience with individualized CTV delineation based on stepwise patterns of spread results in excellent local control, with no recurrence outside the GTV.
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Neoplasias de Cabeça e Pescoço/radioterapia , Carcinoma Nasofaríngeo/radioterapia , Radioterapia/métodos , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Neoplasias Nasofaríngeas/radioterapia , Metástase Neoplásica , Recidiva Local de Neoplasia , Terapia com Prótons , Lesões por Radiação , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: To evaluate the effect of angle modification of cranial field proton beam therapy on the radiation dose delivered to the lens during craniospinal irradiation (CSI). METHODS AND MATERIALS: Thirty-nine patients with central nervous system tumors who received CSI with a posterior fossa boost were analyzed for the radiation dose to the lens. Thirteen patients received cranial field treatment using standard opposed-lateral proton beams, and 26 patients received treatment with angled posterior-oblique proton beams. The lens dose in a test case also was evaluated by comparing conventional X-rays with the two proton beam planning methods by using a CMS/Xio three-dimensional planning system. RESULTS: Substantial lens dose sparing was realized with the angling of the cranial proton beams 15 degrees -20 degrees to the posterior. In the 39 treated patients who were analyzed (median age, 7 years), average dose delivered to the lens was decreased by approximately 50% by angling of the proton beams, with the average maximum dose decreasing from 74% to 40% of the prescribed dose (p < 0.0001). Significant lens sparing was seen in patients 10 years and younger (median age, 6 years; p < 0.0001), whereas an insignificant decrease was seen in older patients (median age, 16 years; p = 0.14). With the opposed-lateral technique (median age, 6 years), the lens dose increased significantly with decreasing age (p = 0.002), whereas there was no effect of age on lens dose in the angled beam-treated group (median age, 8.5 years; p = 0.73). CONCLUSION: The present study clearly shows an advantage in sparing of the lens dose by angling the beams used during proton beam CSI. This effect is most pronounced in patients 10 years and younger because of anatomic effects of sinus development.
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Neoplasias do Sistema Nervoso Central/radioterapia , Irradiação Craniana/métodos , Cristalino/efeitos da radiação , Adolescente , Adulto , Fatores Etários , Neoplasias Cerebelares/radioterapia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Meduloblastoma/radioterapia , Terapia com Prótons , Doses de Radiação , Lesões por Radiação/prevenção & controleRESUMO
Patient safety may be at risk when details are omitted during anesthesia handoff. The Written Handoff Anesthesia Tool (WHAT), designed by the author, was implemented to improve the quality of anesthesia handoffs in the operating room and postanesthesia care unit (PACU). The author used the Anesthesia Handoff Communication survey to evaluate Certified Registered Nurse Anesthetist (CRNA) and PACU registered nurse (RN) satisfaction with anesthesia handoff and the Targeted Solutions Tool to identify the adequacy, contributing factors, and specific patient data omitted by senders of anesthesia handoff before and after implementation of the WHAT. Adequacy of the handoff process significantly improved for CRNAto-PACU RN (P < .0001) and CRNA-to-CRNA (P < .0001) handoffs. After implementation of the WHAT, satisfaction with anesthesia handoff significantly improved for CRNAs (P < .001) and PACU RNs (P = .001). Factors contributing to inadequate handoffs and omitted patient details were identified and significantly improved for CRNA-to-PACU RN and CRNA-to-CRNA handoffs, respectfully: ineffective method (P < .001; P < .001), baseline vital signs (P = .009; P = .014), and preoperative neurologic status (P = .012; P = .004). Implementation of the WHAT led to evidence-based changes in practice, standardization, and improved anesthesia handoff communication.
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Anestesiologia/normas , Lista de Checagem/normas , Transferência da Responsabilidade pelo Paciente/normas , Humanos , Enfermeiros Anestesistas , Melhoria de QualidadeRESUMO
PURPOSE: To compare intensity-modulated photon radiotherapy (IMRT) with three-dimensional conformal proton therapy (3D-CPT) for early-stage prostate cancer, and explore the potential utility of intensity-modulated proton therapy (IMPT). METHODS AND MATERIALS: Ten patients were planned with both 3D-CPT (two parallel-opposed lateral fields) and IMRT (seven equally spaced coplanar fields). Prescribed dose was 79.2 Gy (or cobalt Gray-equivalent, [CGE] for protons) to the prostate gland. Dose-volume histograms, dose conformity, and equivalent uniform dose (EUD) were compared. Additionally, plans were optimized for 3D-CPT with nonstandard beam configuration, and for IMPT assuming delivery with beam scanning. RESULTS: At least 98% of the planning target volume received the prescription dose. IMRT plans yielded better dose conformity to the target, whereas proton plans achieved higher dose homogeneity and better sparing of rectum and bladder in the range below 30 Gy/CGE. Bladder volumes receiving more than 70 Gy/CGE (V70) were reduced, on average, by 34% with IMRT vs. 3D-CPT, whereas rectal V70 were equivalent. EUD from 3D-CPT and IMRT plans were indistinguishable within uncertainties for both bladder and rectum. With the use of small-angle lateral-oblique fields in 3D-CPT and IMPT, the rectal V70 was reduced by up to 35% compared with the standard lateral configuration, whereas the bladder V70 increased by less than 10%. CONCLUSIONS: In the range higher than 60 Gy/CGE, IMRT achieved significantly better sparing of the bladder, whereas rectal sparing was similar with 3D-CPT and IMRT. Dose to healthy tissues in the range lower than 50% of the target prescription was substantially lower with proton therapy.
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Neoplasias da Próstata/radioterapia , Terapia com Prótons , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Masculino , Estadiamento de Neoplasias , Fótons/uso terapêutico , Neoplasias da Próstata/patologia , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Reto/efeitos da radiação , Carga Tumoral , Bexiga Urinária/efeitos da radiaçãoRESUMO
OBJECTIVES: Management of unresectable adenocystic carcinoma (ACC) of the nasopharynx is challenging given the high dose required for tumor control while respecting dose constraints. We evaluated long-term outcomes and toxicity in patients with unresectable ACC of the nasopharynx treated with definitive proton beam therapy. METHODS: Between 2000 and 2013, 14 patients with ACC of the nasopharynx were treated. Ninety-three percent had T4 disease. All had involvement of the skull base. Seventy-nine percent and 21% of patients underwent biopsy and endoscopic debulking surgery, respectively. Median dose was 73.8Gy (RBE). Fifty percent of patients received concurrent chemotherapy. Locoregional control and overall survival probabilities were estimated by the Kaplan-Meier method. Treatment toxicity was scored by the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Median follow-up of surviving patients was 69months. There were 3 local, 1 regional, and 4 distant failures. Median time of local failures was 69months (range: 63-161). All local recurrences were within previous high-dose regions. Four patients developed metastatic disease at a median of 30months (range: 4-64). Five-year overall survival was 59%. The most common cause of death was due to metastatic disease. There was one acute grade 3 toxicity. No patient required gastrostomy tube or hospitalization. Three patients developed grade 3 or higher late toxicity. Two of these patients received combined modality treatment. With 176months follow-up, no second cancer was observed. CONCLUSION: Proton beam therapy results in promising local control with acceptable toxicity in patients with unresectable ACC of the nasopharynx. As late recurrence is common, longer follow-up is necessary to confirm our findings.
Assuntos
Carcinoma Adenoide Cístico/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Terapia com Prótons , Base do Crânio/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de NeoplasiaRESUMO
PURPOSE: To evaluate and understand the tolerance of the thoracolumbar spinal cord using equivalent uniform dose (EUD) and dose volume histogram (DVH) analysis after combined high dose photon-proton radiotherapy. MATERIALS AND METHODS: A total of 68 patients were identified as having high dose radiotherapy, ⩾5900cGy (RBE) in the region of the thoracolumbar spinal cord, defined as extending inferiorly to L2. Pathological diagnosis for patients in this review included chordoma (50 patients, 53.1%), chondrosarcoma (28 patients, 29.8%), osteosarcoma (3 patients, 3.2%), other sarcoma (11 patients, 11.7%), and other (2 patients, 2.1%). Patient data were reviewed retrospectively, detailed dose volume histogram data (DVH) were available for 23 patients. Composite plans and DVH were constructed for both pre-operative and post-operative radiation therapy courses in MIM-Vista software, as available. Dose constraints to the center and surface of the cord were 5400cGy (RBE), and 6300cGy (RBE) respectively, and patients receiving concurrent chemotherapy received an eight percent dose reduction. Spinal cord toxicity was recorded using the RTOG/EORTC late effects scoring system. RESULTS: Clinical and dosimetric data for each patient were analyzed. Median prescription dose was 7020cGy (RBE), range (5940-7820cGy (RBE)). Median follow-up was 12.9months. Five-year overall survival for all patients in this group was 88.7%, 95%CI (74.7-95.2). One patient suffered from transient paralysis following stem cell transplant for treatment of myelodysplastic syndrome. Other reasons for spinal cord injury following treatment included: local disease progression, noted in 7 patients (10.3%), and direct result of surgery, noted in 8 patients (11.8%). Freedom from neurological injury (RTOG Grade 2 or higher) at 5years was 92.9%(95%CI: 74.6-98.2), at 6years was 80.9%(95%CI: 55.3-92.7), and at 8years 80.9%(95%CI: 55.3-92.7). CONCLUSION: Our clinical and dosimetric data suggest that the noted dose constraints are safe and acceptable with regard to spinal cord complications. Pre-existing disease characteristics, surgical complications, as well as tumor progression, appear to be more important factors when it comes to spinal cord toxicity.
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Cordoma/radioterapia , Radioterapia Conformacional/métodos , Sarcoma/radioterapia , Neoplasias da Medula Espinal/radioterapia , Medula Espinal/efeitos da radiação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Estudos Retrospectivos , Adulto JovemRESUMO
PURPOSE: Squamous cell carcinoma (SCC) is the most common sinonasal cancer and is associated with one of the poor outcomes. Proton therapy allows excellent target coverage with maximal sparing of adjacent normal tissues. We evaluated the long-term outcomes in patients with sinonasal SCC treated with proton therapy. METHODS AND MATERIALS: Between 1991 and 2008, 54 patients with Stage III and IV SCC of the nasal cavity and paranasal sinus received proton beam therapy at our institution to a median dose of 72.8 Gy(RBE). Sixty-nine percent underwent prior surgical resection, and 74% received elective nodal radiation. Locoregional control and survival probabilities were estimated with the Kaplan-Meier method. Multivariate analyses were performed using the Cox proportional-hazards model. Treatment toxicity was scored using the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: With a median follow-up time of 82 months in surviving patients, there were 10 local, 7 regional, and 11 distant failures. The 2-year and 5-year actuarial local control rate was 80%. The 2-year and 5-year rates of overall survival were 67% and 47%, respectively. Only smoking status was predictive for worse locoregional control, with current smokers having a 5-year rate of 23% compared with 83% for noncurrent smokers (P=.004). Karnofsky performance status ≤80 was the most significant factor predictive for worse overall survival in multivariate analysis (adjusted hazard ratio 4.5, 95% confidence interval 1.6-12.5, P=.004). There were nine grade 3 and six grade 4 toxicities, and no grade 5 toxicity. Wound adverse events constituted the most common grade 3-4 toxicity. CONCLUSIONS: Our long-term results show that proton radiation therapy is well tolerated and yields good locoregional control for SCC of the nasal cavity and paranasal sinus. Current smokers and patients with poor performance status had inferior outcomes. Prospective study is necessary to compare IMRT with proton therapy in the treatment of sinonasal malignancy.
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Carcinoma de Células Escamosas/radioterapia , Neoplasias Nasais/radioterapia , Terapia com Prótons/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Avaliação de Estado de Karnofsky , Irradiação Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/mortalidade , Neoplasias Nasais/patologia , Neoplasias Nasais/cirurgia , Neoplasias dos Seios Paranasais/mortalidade , Neoplasias dos Seios Paranasais/patologia , Neoplasias dos Seios Paranasais/radioterapia , Neoplasias dos Seios Paranasais/cirurgia , Modelos de Riscos Proporcionais , Terapia com Prótons/efeitos adversos , Lesões por Radiação/patologia , Dosagem Radioterapêutica , Eficiência Biológica Relativa , Fumar/efeitos adversos , Taxa de SobrevidaRESUMO
BACKGROUND: Central nervous system (CNS) injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. METHODS AND MATERIALS: We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. RESULTS: At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values (P=.12). CONCLUSIONS: Central nervous system and brainstem injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between injury and LET.
Assuntos
Tronco Encefálico/efeitos da radiação , Neoplasias Cerebelares/radioterapia , Irradiação Craniana/efeitos adversos , Meduloblastoma/radioterapia , Terapia com Prótons/efeitos adversos , Lesões por Radiação/epidemiologia , Medula Espinal/efeitos da radiação , Adolescente , Tronco Encefálico/diagnóstico por imagem , Neoplasias Cerebelares/tratamento farmacológico , Cerebelo/efeitos da radiação , Vértebras Cervicais , Criança , Pré-Escolar , Estudos de Coortes , Irradiação Craniana/métodos , Feminino , Seguimentos , Humanos , Incidência , Transferência Linear de Energia , Espectroscopia de Ressonância Magnética , Masculino , Meduloblastoma/tratamento farmacológico , Método de Monte Carlo , Tratamentos com Preservação do Órgão/efeitos adversos , Tratamentos com Preservação do Órgão/métodos , Terapia com Prótons/métodos , Lesões por Radiação/diagnóstico , Lesões por Radiação/diagnóstico por imagem , Radiografia , Dosagem Radioterapêutica , Eficiência Biológica Relativa , Fatores de Tempo , Adulto JovemRESUMO
The magnitude of inter- and intrafractional patient motion has been assessed for a broad set of immobilization devices. Data was analyzed for the three ordinal directions--left-right (x), sup-inf (y), and ant-post (z)--and the combined spatial displacement. We have defined "rigid" and "non-rigid" immobilization devices depending on whether they could be rigidly and reproducibly connected to the treatment couch or not. The mean spatial displacement for intrafractional motion for rigid devices is 1.3 mm compared to 1.9 mm for nonrigid devices. The modified Gill-Thomas-Cosman frame performed best at controlling intrafractional patient motion, with a 95% probability of observing a three-dimensional (3D) vector length of motion (v95) of less than 1.8 mm, but could not be evaluated for interfractional motion. All other rigid and nonrigid immobilization devices had a v95 of more than 3 mm for intrafractional patient motion. Interfractional patient motion was only evaluated for the rigid devices. The mean total interfractional displacement was at least 3.0 mm for these devices while v95 was at least 6.0 mm.
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Imageamento Tridimensional/métodos , Imobilização/métodos , Radioterapia/instrumentação , Radioterapia/métodos , Algoritmos , Desenho de Equipamento , Humanos , Movimento (Física) , Movimento , Postura , Prótons , Reprodutibilidade dos Testes , Restrição FísicaRESUMO
CONTEXT: Clinically localized prostate cancer is very prevalent among US men, but recurrence after treatment with conventional radiation therapy is common. OBJECTIVE: To evaluate the hypothesis that increasing the radiation dose delivered to men with clinically localized prostate cancer improves disease outcome. DESIGN, SETTING, AND PATIENTS: Randomized controlled trial of 393 patients with stage T1b through T2b prostate cancer and prostate-specific antigen (PSA) levels less than 15 ng/mL randomized between January 1996 and December 1999 and treated at 2 US academic institutions. Median age was 67 years and median PSA level was 6.3 ng/mL. Median follow-up was 5.5 (range, 1.2-8.2) years. INTERVENTION: Patients were randomized to receive external beam radiation to a total dose of either 70.2 Gy (conventional dose) or 79.2 Gy (high dose). This was delivered using a combination of conformal photon and proton beams. MAIN OUTCOME MEASURE: Increasing PSA level (ie, biochemical failure) 5 years after treatment. RESULTS: The proportions of men free from biochemical failure at 5 years were 78.8% [corrected] (95% confidence interval, 73.1%-84.6%) [corrected] for conventional-dose and 91.3% [corrected] (95% confidence interval, 87.2%-95.4%) [corrected] for high-dose therapy (P<.001), a 59% [corrected] reduction in the risk of failure. The advantage to high-dose therapy was statistically significant [corrected] in both the low-risk subgroup [corrected] (risk reduction, 84% [P<.001]) [corrected] There has been no significant difference in overall survival rates between the treatment groups. Only 1% of patients receiving conventional-dose and 2% receiving high-dose radiation experienced acute urinary or rectal morbidity of Radiation Therapy Oncology Group (RTOG) grade 3 or greater. So far, only 2% and 1%, respectively, have experienced late morbidity of RTOG grade 3 or greater. CONCLUSIONS: Men with clinically localized prostate cancer have a lower risk of biochemical failure if they receive high-dose rather than conventional-dose conformal radiation. This advantage was achieved without any associated increase in RTOG grade 3 acute or late urinary or rectal morbidity.
Assuntos
Adenocarcinoma/radioterapia , Neoplasias da Próstata/radioterapia , Dosagem Radioterapêutica , Adenocarcinoma/sangue , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Radioterapia ConformacionalRESUMO
BACKGROUND: Palliative care in intensive care units (ICUs) reduces costs and improves outcomes yet is consistently underused; studies suggest that screening tools increase the use of palliative services. AIMS: This project piloted the use of the Palliative Performance Scale, version 2 (PPSv2), as a trigger for palliative care referrals in a 12-bed medical ICU. METHODS: Using a preintervention-postintervention design, the authors measured the effect of the intervention on nurses' comfort and knowledge in assessing palliative care needs, number of palliative care referrals, and number of days between ICU admission and palliative care referral. The authors also measured uptake of the scale over 12 weeks of implementation and asked nurses to share their thoughts about using the PPSv2. RESULTS: Over 610 observations, the rate of uptake increased over time and use of the scale ranged from 24.2% to 85.6%. The nurses' (n = 26) comfort with palliative care issues increased from preintervention to postintervention, albeit not significantly. Knowledge items did not change. There was a 110% increase in the number of palliative care referrals between preintervention and postintervention and a nearly 1-day decrease in the number of days between medical ICU admission and palliative care referral; this reduction was not statistically significant. A majority of nurses (n = 22 [84.5%]) voted to retain the PPSv2 as an official process of care, stating that the tool facilitated assessment of patient needs that might have been previously overlooked. CONCLUSION: Data suggest that the PPSv2 was well received by the bedside nurses and changed practice patterns with regard to facilitating palliative care services.
Assuntos
Cuidados Críticos/normas , Unidades de Terapia Intensiva/organização & administração , Cuidados Paliativos/normas , Equipe de Assistência ao Paciente/organização & administração , Encaminhamento e Consulta , Humanos , Capacitação em Serviço , Unidades de Terapia Intensiva/normas , Recursos Humanos de Enfermagem Hospitalar , Cuidados Paliativos/estatística & dados numéricos , Projetos PilotoRESUMO
PURPOSE: To calculate the dose in time-dependent geometry, the results of three-dimensional calculations are usually performed separately and combined. This approach becomes cumbersome when high temporal resolution is required, if the geometry is complex, or if interplay effects between different, independently moving systems are to be studied. The purpose of this project was the implementation of continuous (four-dimensional [4D]) Monte Carlo simulation to study the irradiation of tumors under respiratory motion. METHODS AND MATERIALS: In taking advantage of object-oriented programming, we implemented 4D Monte Carlo dose calculation. Local dose depositions in the patient are calculated while beam configuration and organ positions are changed continuously. Deformable image registration is used to describe the CT voxel displacement over time. RESULTS: The 4D Monte Carlo technique is applied to a lung cancer case planned for proton therapy. We show that the effect of motion on the dose distribution can be simulated effectively based on statistical motion parameterizations acting on the geometry or based on patient-specific 4D CT information. CONCLUSION: We present a novel method able to calculate dose with underlying time-dependent geometry. The technique allows 4D dose calculation in arbitrary time scales in a single simulation even for double-dynamic systems (e.g., time-dependent beam delivery under organ motion).
Assuntos
Neoplasias Pulmonares/radioterapia , Método de Monte Carlo , Movimento , Planejamento da Radioterapia Assistida por Computador/métodos , Respiração , Estudos de Viabilidade , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Radiografia , Dosagem Radioterapêutica , Radioterapia Conformacional/métodosRESUMO
Clinical results from various trials have demonstrated the viability of protons in radiation therapy and radiosurgery. This has motivated a few large medical centers to design and build expensive hospital based proton facilities based proton facilities (current cost estimates for a proton facility is around 100 million US dollars). Until this development proton therapy was done using retrofitted equipment originally designed for nuclear experiments. There are presently only three active proton therapy centers in the United States, 22 worldwide. However, more centers are under construction and being proposed in the US and abroad. The important difference between proton and x-ray therapy is in the dose distribution. X-rays deposit most of their dose at shallow depths of a few centimeters with a gradual decay with depth in the patient. Protons deliver most of their dose in the Bragg peak, which can be delivered at most clinically required depths followed by a sharp fall-off. This sharp falloff makes protons sensitive to variations in treatment depths within patients. Treatment planning incorporates all the knowledge of protons into a process, which allows patients to be treated accurately and reliably. This process includes patient immobilization, imaging, targeting, and modeling of planned dose distributions. Although the principles are similar to x-ray therapy some significant differences exist in the planning process, which described in this paper. Target dose conformality has recently taken on much momentum with the advent of intensity modulated radiation therapy (IMRT) with photon beams. Proton treatments provide a viable alternative to IMRT because they are inherently conformal avoiding normal tissue while irradiating the intended targets. Proton therapy will soon bring conformality to a new high with the development of intensity modulated proton therapy (IMPT). Future challenges include keeping the cost down, increasing access to conventional proton therapy as well as the clinical implementation of IMPT. Computing advances are making Monte Carlo techniques more accessible to treatment planning for all modalities including proton therapy. This technique will allow complex delivery configurations to be properly modeled in a clinical setting.
Assuntos
Terapia com Prótons , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Humanos , Imageamento Tridimensional , Dosagem RadioterapêuticaRESUMO
OBJECTIVES: To explore how family members of ICU patients at high risk of dying respond to nursing communication strategies. BACKGROUND: Family members of ICU patients may face difficult decisions. Nurses are in a position to provide support. Evidence of specific strategies that nurses use to support decision-making and how family members respond to these strategies is lacking. METHODS: This is a prospective, qualitative descriptive study involving the family members of ICU patients identified as being at high risk of dying. RESULTS: Family members described five nursing approaches: Demonstrating concern, building rapport, demonstrating professionalism, providing factual information, and supporting decision-making. This study provides evidence that when using these approaches, nurses helped family members to cope; to have hope, confidence, and trust; to prepare for and accept impending death; and to make decisions. CONCLUSION: Knowledge lays a foundation for interventions targeting the areas important to family members and most likely to improve their ability to make decisions and their well-being.
Assuntos
Atitude Frente a Morte , Família/psicologia , Papel do Profissional de Enfermagem , Relações Profissional-Família , Adulto , Idoso , Comunicação , Tomada de Decisões , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Confiança , Adulto JovemRESUMO
OBJECTIVE: Using the Adaptive Leadership framework, we describe behaviours that providers used while interacting with family members facing the challenges of recognising that their loved one was dying in the ICU. RESEARCH METHODOLOGY: In this prospective pilot case study, we selected one ICU patient with end-stage illness who lacked decision-making capacity. Participants included four family members, one nurse and two physicians. The principle investigator observed and recorded three family conferences and conducted one in-depth interview with the family. Three members of the research team independently coded the transcripts using a priori codes to describe the Adaptive Leadership behaviours that providers used to facilitate the family's adaptive work, met to compare and discuss the codes and resolved all discrepancies. FINDINGS: We identified behaviours used by nurses and physicians that facilitated the family's ability to adapt to the impending death of a loved one. Examples of these behaviours include defining the adaptive challenges for families and foreshadowing a poor prognosis. CONCLUSIONS: Nurse and physician Adaptive Leadership behaviours can facilitate the transition from curative to palliative care by helping family members do the adaptive work of letting go. Further research is warranted to create knowledge for providers to help family members adapt.