RESUMEN
In the last few years, the manufacturing of microelectromechanical systems (MEMS) by means of innovative tridimensional and bidimensional printing technologies has significantly catalyzed the attention of researchers. Inkjet material deposition, in particular, can become a key enabling technology for the production of polymer-based inertial sensors characterized by low cost, high manufacturing scalability and superior sensitivity. In this paper, a fully inkjet-printed polymeric accelerometer is proposed, and its manufacturing steps are described. The manufacturing challenges connected with the inkjet deposition of SU-8 as a structural material are identified and addressed, resulting in the production of a functional spring-mass sensor. A step-crosslinking process allows optimization of the final shape of the device and limits defects typical of inkjet printing. The resulting device is characterized from a morphological point of view, and its functionality is assessed in performing optical readout. The acceleration range of the optimized device is 0-0.7 g, its resolution is 2 × 10-3 g and its sensitivity is 6745 nm/g. In general, the work demonstrates the feasibility of polymeric accelerometer production via inkjet printing, and these characteristic parameters demonstrate their potential applicability in a broad range of uses requiring highly accurate acceleration measurements over small displacements.
RESUMEN
BACKGROUND: Preoperative chemoradiotherapy (CRT) is the standard treatment for T3-4 rectal cancer. Here, we compared image-guided and intensity-modulated RT (IG-IMRT) with a simultaneous integrated boost (SIB) (instead of concomitant chemotherapy) versus CRT in a multi-centric randomized trial. METHODS: cT3-4 rectal cancer patients were randomly assigned to receive preoperative IG-IMRT 46 Gy/23 fractions plus capecitabine 825 mg/m² twice daily (CRT arm) or IG-IMRT 46 Gy/23 fractions with an SIB to the rectal tumor up to a total dose of 55.2 Gy (RTSIB arm). RESULTS: A total of 174 patients were randomly assigned between April 2010 and May 2014. Grade 3 acute toxicities were 6% and 4% in the CRT and RTSIB arms, respectively. The mean fractional change in SUVmax at 5 weeks after completion of preoperative RT were -55.8% (±24.0%) and -52.9% (±21.6%) for patients in the CRT arm and RTSIB arm, respectively (p = 0.43). The pathologic complete response rate was 24% with CRT compared to 14% with RTSIB. There were no differences in 5-year overall survival (OS), progression-free survival (PFS) or local control (LC). CONCLUSIONS: The preoperative RTSIB approach was not inferior to CRT in terms of metabolic response, toxicity, OS, PFS and LC, and could be considered an available option for patients unfit for fluorouracil-based CRT.
RESUMEN
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.
Asunto(s)
Neoplasias Pancreáticas , Radiocirugia , Humanos , Estudios Retrospectivos , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/radioterapia , Páncreas , Quimioradioterapia , Radiocirugia/métodosRESUMEN
PURPOSE: To validate published models for the risk estimate of grade ≥ 1 (G1+), grade ≥ 2 (G2+) and grade = 3 (G3) late rectal bleeding (LRB) after radical radiotherapy for prostate cancer in a large pooled population from three prospective trials. MATERIALS AND METHODS: The external validation population included patients from Europe, and Oceanian centres enrolled between 2003 and 2014. Patients received 3DCRT or IMRT at doses between 66-80 Gy. IMRT was administered with conventional or hypofractionated schemes (2.35-2.65 Gy/fr). LRB was prospectively scored using patient-reported questionnaires (LENT/SOMA scale) with a 3-year follow-up. All Normal Tissue Complication Probability (NTCP) models published until 2021 based on the Equivalent Uniform Dose (EUD) from the rectal Dose Volume Histogram (DVH) were considered for validation. Model performance in validation was evaluated through calibration and discrimination. RESULTS: Sixteen NTCP models were tested on data from 1633 patients. G1+ LRB was scored in 465 patients (28.5%), G2+ in 255 patients (15.6%) and G3 in 112 patients (6.8%). The best performances for G2+ and G3 LRB highlighted the importance of the medium-high doses to the rectum (volume parameters n = 0.24 and n = 0.18, respectively). Good performance was seen for models of severe LRB. Moreover, a multivariate model with two clinical factors found the best calibration slope. CONCLUSION: Five published NTCP models developed on non-contemporary cohorts were able to predict a relative increase in the toxicity response in a more recent validation population. Compared to QUANTEC findings, dosimetric results pointed toward mid-high doses of rectal DVH. The external validation cohort confirmed abdominal surgery and cardiovascular diseases as risk factors.
Asunto(s)
Neoplasias de la Próstata , Recto , Masculino , Humanos , Dosificación Radioterapéutica , Estudios Prospectivos , Hemorragia Gastrointestinal/etiología , Factores de Riesgo , Neoplasias de la Próstata/radioterapiaRESUMEN
The study aimed to generate a local failure (LF) risk map in resected pancreatic cancer (PC) and validate the results of previous studies, proposing new guidelines for PC postoperative radiotherapy clinical target volume (CTV) delineation. Follow-up computer tomography (CT) of resected PC was retrospectively reviewed by two radiologists identifying LFs and plotting them on a representative patient CT scan. The percentages of LF points randomly extracted based on CTV following the RTOG guidelines and based on the LF database were 70% and 30%, respectively. According to the Kernel density estimation, an LF 3D distribution map was generated and compared with the results of previous studies using a Dice index. Among the 64 resected patients, 59.4% underwent adjuvant treatment. LFs closer to the root of the celiac axis (CA) or the superior mesenteric artery (SMA) were reported in 32.8% and 67.2% cases, respectively. The mean (± standard deviation) distances of LF points to CA and SMA were 21.5 ± 17.9 mm and 21.6 ± 12.1 mm, respectively. The Dice values comparing our iso-level risk maps corresponding to 80% and 90% of the LF probabilistic density and the CTVs-80 and CTVs-90 of previous publications were 0.45-0.53 and 0.58-0.60, respectively. According to the Kernel density approach, a validated LF map was proposed, modeling a new adjuvant CTV based on a PC pattern of failure.
RESUMEN
Engineering T cells to express chimeric antigen receptors (CARs) specific for antigens on hematological cancers has yielded remarkable clinical responses, but with solid tumors, benefit has been more limited. This may reflect lack of suitable target antigens, immune evasion mechanisms in malignant cells, and/or lack of T cell infiltration into tumors. An alternative approach, to circumvent these problems, is targeting the tumor vasculature rather than the malignant cells directly. CLEC14A is a glycoprotein selectively overexpressed on the vasculature of many solid human cancers and is, therefore, of considerable interest as a target antigen. Here, we generated CARs from 2 CLEC14A-specific antibodies and expressed them in T cells. In vitro studies demonstrated that, when exposed to their target antigen, these engineered T cells proliferate, release IFN-γ, and mediate cytotoxicity. Infusing CAR engineered T cells into healthy mice showed no signs of toxicity, yet these T cells targeted tumor tissue and significantly inhibited tumor growth in 3 mouse models of cancer (Rip-Tag2, mPDAC, and Lewis lung carcinoma). Reduced tumor burden also correlated with significant loss of CLEC14A expression and reduced vascular density within malignant tissues. These data suggest the tumor vasculature can be safely and effectively targeted with CLEC14A-specific CAR T cells, offering a potent and widely applicable therapy for cancer.
Asunto(s)
Carcinoma Pulmonar de Lewis/prevención & control , Carcinoma Ductal Pancreático/prevención & control , Moléculas de Adhesión Celular/metabolismo , Inmunoterapia Adoptiva/métodos , Lectinas Tipo C/metabolismo , Neovascularización Patológica/prevención & control , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Animales , Carcinoma Pulmonar de Lewis/inmunología , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Pulmonar de Lewis/patología , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Moléculas de Adhesión Celular/genética , Femenino , Células Endoteliales de la Vena Umbilical Humana , Humanos , Lectinas Tipo C/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Neovascularización Patológica/inmunología , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/prevención & controlRESUMEN
Conventionally fractionated chemoradiation (CRT) or chemotherapy (CHT) are considered as standard options in locally advanced pancreatic cancer (LAPC) while stereotactic body radiotherapy (SBRT) is an emerging treatment in this setting. The aim of this study was to compare two cohorts of LAPC patients treated with SBRT ± CHT vs CRT ± CHT in terms of local control (LC), distant metastases-free survival (DMFS), progression-free survival (PFS), overall survival (OS), and toxicity. Eighty patients were included. Patients in the two cohorts were matched according to: age ≤/>65 years, tumor diameter (two cut-offs: ≥3.0 and ≥3.9 cm), clinical tumor stage and clinical nodal stage, neoadjuvant CHT, and adjuvant CHT. Median prescribed total dose was 30.0 Gy (range: 18.0-37.5) and 54.0 Gy (18.0-63.0) in SBRT and CRT cohorts, respectively. Toxicity was evaluated by CTCAE v4.0 scale. Survival curves were calculated by Kaplan-Meier method. For hypothesis testing an equivalence and a non-inferiority test was calculated. No statistically significant differences in terms of acute and late toxicity, DMFS, PFS, and OS were recorded among the two cohorts. Median, 1-, and 2-year LC was: 16.0 months, 53.1%, and 40.5% in the CRT cohort and 22.0 months, 80.4%, and 49.8% in the SBRT cohort, respectively (P: .017). A statistically non-inferiority significance was recorded in terms of OS between CRT and SBRT (P = .031). Patients treated with SBRT showed higher LC rate and similar OS compared to CRT. Therefore, the design of confirmatory randomized studies comparing SBRT and CRT seems justified.
Asunto(s)
Quimioradioterapia , Fraccionamiento de la Dosis de Radiación , Neoplasias Pancreáticas/terapia , Radiocirugia , Adulto , Anciano , Anciano de 80 o más Años , Quimioradioterapia/efectos adversos , Quimioradioterapia/mortalidad , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Supervivencia sin Progresión , Radiocirugia/efectos adversos , Radiocirugia/mortalidad , Estudios Retrospectivos , Factores de Riesgo , Factores de TiempoRESUMEN
Objective: To investigate predictors of patient-reported urinary incontinence (PRUI) in the first 2 years after post-prostatectomy radiotherapy (PORT) with particular emphasis on possible dose-effect relationships. Patients and Methods: Two-hundred-thirteen patients, whose clinical and dosimetric data were prospectively collected within a registered multi-institutional cohort study, underwent PORT with adjuvant (n = 106) or salvage (n = 107) intent with conventional (n = 123, prescribed dose to the prostatic bed: 66.6-79.8Gy in 1.8-2.0Gy/fr) or moderately hypo- (n = 90, 65.8-76.8Gy in 2.1-2.7Gy/fr) fractionation during the period 2011-2017. PRUI was evaluated through the ICIQ-SF questionnaire filled in at baseline and every 6 months thereafter. The analysis focused on three ICIQ-based clinically relevant endpoints: (a) very frequent leakage (FREQUENCY, ICIQ3 score >3), (b) moderate to severe amount of urine loss (AMOUNT, ICIQ4>2) (c) objective severe symptoms (OBJECTIVE, ICIQ3+4>5). Predictors of the incidence within 2 years for the three endpoints were investigated focusing only on patients without endpoint symptoms at baseline. A uni-variable logistic regression analysis was performed in order to determine the best dose metrics describing PRUI risk in terms of 2-Gy equivalent dose (EQD2) calculated with different α/ß values reported in the literature (0.8, 3, 5Gy), and to identify the most significant clinical variables. Variables showing p < 0.20 at uni-variable analysis were entered into a backward stepwise multi-variable logistic regression analysis. Lastly, the goodness of fit and model calibration were evaluated and internally validated. Results: Patients without symptoms at baseline experienced (a), (b), and/or (c) within 2 years in 41/130 (32%), 40/192 (21%), and 41/129 (32%) of the cases, respectively. EQD2 for α/ß = 0.8Gy was the best dose metric associated with PRUI. Multi-variable analysis identified baseline incontinence levels as the strongest predictor for all endpoints (p < 0.006). Both FREQUENCY and OBJECTIVE were significantly influenced also by EQD2(α/ß = 0.8Gy). The goodness of fit was excellent, as was the calibration; internal calibration confirmed apparent performance. Conclusion: Baseline mild urinary incontinence symptoms strongly modulate the 2-year risk of PRUI. In addition, FREQUENCY is characterized by a marked dose-effect relationship also influencing the trend of OBJECTIVE, with results more reliable than AMOUNT as an objective index. A strong impact of fractionation on severe PRUI after post-prostatectomy radiotherapy also emerged.
RESUMEN
Purpose: The aim of this work was to determine how the spatial pattern of dose in the ano-rectal wall is related to late gastro-intestinal toxicity for prostate cancer patients treated with mainly IMRT.Patients and methods: Patients from the DUE-01 multicentre study with patient-reported (prospective) follow-up and available dosimetric data were included. Conventionally fractionated patients received 74-80 Gy and hypofractionated patients received 65-75.2 Gy. A large majority of the patients were treated with intensity-modulated radiotherapy (IMRT). Dose-surface maps (DSMs) for the anal canal and rectum as a single structure, and for the anal canal and the rectum separately, were co-registered rigidly in two dimensions and, for the patients with and without toxicity, respectively, the mean value of the dose in each pixel was calculated. A pixel-wise t-test was used to highlight the anatomical areas where there was a significant difference between the 'mean dose maps' of each group. Univariate models were also fitted to a range of spatial parameters. The endpoints considered were a mean grade ≥1 late fecal incontinence and a maximum grade ≥2 late rectal bleeding.Results: Twenty-six out of 213 patients had fecal incontinence, while 21/225 patients had rectal bleeding. Incontinence was associated with a higher dose in the caudal region of the anal canal; the most relevant spatial parameter was the lateral extent of the low and medium isodoses (5-49 Gy in EQD2). Bleeding was associated with high isodoses reaching the posterior rectal wall. The spatial dose parameters with the highest AUC value (.69) were the lateral extent of the 60-70 Gy isodoses.Conclusions: To avoid fecal incontinence it is important to limit the portion of the anal canal irradiated. Our analysis confirms that rectal bleeding is a function of similar spatial dose parameters for patients treated with IMRT, compared to previous studies on patients treated with three-dimensional conformal radiotherapy.
Asunto(s)
Canal Anal/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Radioterapia de Intensidad Modulada/efectos adversos , Recto/efectos de la radiación , Fraccionamiento de la Dosis de Radiación , Incontinencia Fecal/etiología , Hemorragia Gastrointestinal/etiología , Humanos , Masculino , Estudios Prospectivos , Radioterapia de Intensidad Modulada/métodos , Enfermedades del Recto/etiología , RiesgoRESUMEN
PURPOSE: REQUITE aimed to establish a resource for multi-national validation of models and biomarkers that predict risk of late toxicity following radiotherapy. The purpose of this article is to provide summary descriptive data. METHODS: An international, prospective cohort study recruited cancer patients in 26 hospitals in eight countries between April 2014 and March 2017. Target recruitment was 5300 patients. Eligible patients had breast, prostate or lung cancer and planned potentially curable radiotherapy. Radiotherapy was prescribed according to local regimens, but centres used standardised data collection forms. Pre-treatment blood samples were collected. Patients were followed for a minimum of 12 (lung) or 24 (breast/prostate) months and summary descriptive statistics were generated. RESULTS: The study recruited 2069 breast (99% of target), 1808 prostate (86%) and 561 lung (51%) cancer patients. The centralised, accessible database includes: physician- (47,025 forms) and patient- (54,901) reported outcomes; 11,563 breast photos; 17,107 DICOMs and 12,684 DVHs. Imputed genotype data are available for 4223 patients with European ancestry (1948 breast, 1728 prostate, 547 lung). Radiation-induced lymphocyte apoptosis (RILA) assay data are available for 1319 patients. DNA (nâ¯=â¯4409) and PAXgene tubes (nâ¯=â¯3039) are stored in the centralised biobank. Example prevalences of 2-year (1-year for lung) grade ≥2 CTCAE toxicities are 13% atrophy (breast), 3% rectal bleeding (prostate) and 27% dyspnoea (lung). CONCLUSION: The comprehensive centralised database and linked biobank is a valuable resource for the radiotherapy community for validating predictive models and biomarkers. PATIENT SUMMARY: Up to half of cancer patients undergo radiation therapy and irradiation of surrounding healthy tissue is unavoidable. Damage to healthy tissue can affect short- and long-term quality-of-life. Not all patients are equally sensitive to radiation "damage" but it is not possible at the moment to identify those who are. REQUITE was established with the aim of trying to understand more about how we could predict radiation sensitivity. The purpose of this paper is to provide an overview and summary of the data and material available. In the REQUITE study 4400 breast, prostate and lung cancer patients filled out questionnaires and donated blood. A large amount of data was collected in the same way. With all these data and samples a database and biobank were created that showed it is possible to collect this kind of information in a standardised way across countries. In the future, our database and linked biobank will be a resource for research and validation of clinical predictors and models of radiation sensitivity. REQUITE will also enable a better understanding of how many people suffer with radiotherapy toxicity.
Asunto(s)
Neoplasias de la Mama/radioterapia , Neoplasias Pulmonares/radioterapia , Neoplasias de la Próstata/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
OBJECTIVE: This study was undertaken to model the biochemical free survival at 5 years and to evaluate the parameters defining dose-response curve, dose-fractionation radiosensitivity and repopulation. METHODS: It was carried out a literature search on Pubmed to retrieve data sets of patients treated with external beam radiation therapy of 1.8-4.0 Gy per fraction and overall treatment time of 3 to 10 weeks. 10 groups were identified, based on risk class and androgen deprivation therapy (ADT). Dose-response curve D50 (dose at 50% probability of control) and g50 (steepness), α/ß (dose-fractionation radiosensitivity), and repopulation parameters, dprolif and Tprolif , were calculated. Bootstrap-based cross-validation was performed and median and 95% CI (confidence interval) were evaluated. RESULTS: 25 data sets, including 20,310 patients, were considered. The median (95% CI) D50 and g50 values were 62 (CI 53 - 66) Gy and 1.6 (0.8 - 2.4). ADT patients showed lower values of D50 and g50 (57 ± 5 Gy and 1.1 ± 0.4) compared to no-ADT patients (65 ± 2 Gy and 2.3 ± 0.6), with p < 0.0001 and p = 0.002. If we did not consider any dependence on overall treatment time, the median (95% CI) value of α/ß was 1.4 (1.0 - 1.9) Gy with p < 0.0001 for all patients. The median values of dproli f and Tprolif were 0.0 to 0.3 Gy/d and 18-40 days. CONCLUSION: Dose-response curve resulted dependent on risk class and ADT, with higher steepness for no-ADT patients. Low values of dose-fractionation radiosensitivity were found, supporting the use of moderate hypofractionated radiotherapy in each risk class. A limited dependence on repopulation was observed. ADVANCES IN KNOWLEDGE: Prostate cancer response to moderate hypofractionated radiotherapy was reliably quantified considering risk class and androgen deprivation therapy.
Asunto(s)
Neoplasias de la Próstata/radioterapia , Fraccionamiento de la Dosis de Radiación , Relación Dosis-Respuesta en la Radiación , Métodos Epidemiológicos , Humanos , Masculino , Dosificación Radioterapéutica , Resultado del TratamientoRESUMEN
BACKGROUND: To evaluate the outcome of patients treated with salvage radiotherapy after radical prostatectomy and to investigate the effects of independent predictors on survival. METHODS: From January 2000 to December 2015, 234 patients with biochemical/clinical recurrences after radical prostatectomy were submitted to salvage radiotherapy (SRT). One hundred and fifty-seven patients (67%) received three-dimensional (3D) conformal radiotherapy while 77 patients (33%) were treated with intensity-modulated radiotherapy (IMRT) or IMRT/image-guided radiotherapy by tomotherapy. The median RT dose to prostate bed was 70.2 Gy (range: 66-79 Gy). The investigated endpoints were biochemical relapse-free survival (BRFS), clinical relapse-free survival (CRFS), distant metastasis-free survival (DMFS), and prostate cancer-specific survival (PCSS). Different covariates were considered to investigate predictors of survival. RESULTS: With a median follow-up of 117 months the BRFS, CRFS, DMFS and PCSS at 10 years were 54%, 84%, 90%, and 94%, respectively. In multivariate analysis (MVA), the pathological Gleason Score (pGS) was the most important factor affecting BRFS, CRFS, DMFS and PCSS (P<0.007, HR>1.55); pathological stage (pT) was predictor of BRFS (P=0.007, HR=1.7) and PCSS (P=0.02, HR=4.2), and the last prostate-specific antigen during follow-up was an important survival predictor of CRFS (P=0.004, HR=1.26) and PCSS (P<0.0001, HR=1.04). The time between surgery and the start of SRT was correlated with BRFS (P<0.0001, HR=0.987) and CRFS (P=0.047, HR=0.989). In univariate analysis (UVA), positive surgical margins at the prostatectomy specimen improved BRFS (P=0.01, HR=0.54), CRFS (P=0.05, HR=0.46) and DMFS (P=0.005, HR=0.13) after SRT. CONCLUSIONS: At long-term follow-up, excellent outcome results of SRT on BRFS, CRFS, DMFS, and PCSS were obtained. Several prognostic factors such as pGS, pT and surgical margin status were found to be predictors of survival.
Asunto(s)
Prostatectomía , Neoplasias de la Próstata/radioterapia , Terapia Recuperativa/métodos , Adulto , Anciano , Estudios de Cohortes , Estudios de Seguimiento , Humanos , Masculino , Márgenes de Escisión , Persona de Mediana Edad , Clasificación del Tumor , Metástasis de la Neoplasia/prevención & control , Supervivencia sin Progresión , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/cirugía , Radioterapia Guiada por Imagen , Recurrencia , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
PURPOSE: The aim of this paper is to characterize two different EPID-based solutions for pre-treatment VMAT quality assurance, the 2D portal dosimetry and the 3D projection technique. Their ability to catch the main critical delivery errors was studied. METHODS: Measurements were performed with a linac accelerator equipped with EPID aSi1000, Portal Dose Image Prediction (PDIP), and PerFRACTION softwares. Their performances were studied simulating perturbations of a reference plan through systematic variations in dose values and micromultileaf collimator position. The performance of PDIP, based on 2D forward method, was evaluated calculating gamma passing rate (%GP) between no-error and error-simulated measurements. The impact of errors with PerFRACTION, based on 3D projection technique, was analyzed by calculating the difference between reference and perturbed DVH (%ΔD). Subsequently pre-treatment verification with PerFRACTION was done for 27 patients of different pathologies. RESULTS: The sensitivity of PerFRACTION was slightly higher than sensitivity of PDIP, reaching a maximum of 0.9. Specificity was 1 for PerFRACTION and 0.6 for PDIP. The analysis of patients' DVHs indicated that the mean %ΔD was (1.2⯱â¯1.9)% for D2%, (0.6⯱â¯1.7)% for D95% and (-0.0⯱â¯1.2)% for Dmean of PTV. Regarding OARs, we observed important discrepancies on DVH but that the higher dose variations were in low dose area (<10â¯Gy). CONCLUSIONS: This study supports the introduction of the new 3D forward projection method for pretreatment QA raising the claim that the visualization of the delivered dose distribution on patient anatomy has major advantages over traditional portal dosimetry QA systems.
Asunto(s)
Garantía de la Calidad de Atención de Salud/métodos , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Algoritmos , Neoplasias Encefálicas/radioterapia , Neoplasias de la Mama/radioterapia , Calibración , Humanos , Neoplasias Hepáticas/radioterapia , Masculino , Órganos en Riesgo , Aceleradores de Partículas , Neoplasias de la Próstata/radioterapia , Dosificación Radioterapéutica , Sarcoma/radioterapia , Programas InformáticosRESUMEN
PURPOSE: This study was designed to apply artificial neural network (ANN) classification methods for the prediction of late fecal incontinence (LFI) after high-dose prostate cancer radiation therapy and to develop a ready-to-use graphical tool. MATERIALS AND METHODS: In this study, 598 men recruited in 2 national multicenter trials were analyzed. Information was recorded on comorbidity, previous abdominal surgery, use of drugs, and dose distribution. Fecal incontinence was prospectively evaluated through self-reported questionnaires. To develop the ANN, the study population was randomly split into training (n = 300), validation (n = 149), and test (n = 149) sets. Mean grade of longitudinal LFI (ie, expressed as the average incontinence grade over the first 3 years after radiation therapy) ≥1 was considered the endpoint. A suitable subset of variables able to better predict LFI was selected by simulating 100,000 ANN configurations. The search for the definitive ANN was then performed by varying the number of inputs and hidden neurons from 4 to 5 and from 1 to 9, respectively. A final classification model was established as the average of the best 5 among 500 ANNs with the same architecture. An ANN-based graphical method to compute LFI prediction was developed to include one continuous and n dichotomous variables. RESULTS: An ANN architecture was selected, with 5 input variables (mean dose, previous abdominal surgery, use of anticoagulants, use of antihypertensive drugs, and use of neoadjuvant and adjuvant hormone therapy) and 4 hidden neurons. The developed classification model correctly identified patients with LFI with 80.8% sensitivity and 63.7% ± 1.0% specificity and an area under the curve of 0.78. The developed graphical tool may efficiently classify patients in low, intermediate, and high LFI risk classes. CONCLUSIONS: An ANN-based model was developed to predict LFI. The model was translated in a ready-to-use graphical tool for LFI risk classification, with direct interpretation of the role of the predictors.
Asunto(s)
Incontinencia Fecal/etiología , Redes Neurales de la Computación , Neoplasias de la Próstata/radioterapia , Traumatismos por Radiación/etiología , Incontinencia Fecal/diagnóstico , Humanos , Masculino , Pronóstico , Traumatismos por Radiación/diagnóstico , Factores de TiempoRESUMEN
PURPOSE: This study aimed to validate a previously published predictive model for late fecal incontinence (FI) in a contemporary population of prostate cancer patients treated with radical radiation therapy. METHODS AND MATERIALS: The validation included patients treated with intensity-modulated radiation therapy (IMRT) (2010-2014). Prescribed dose range was 65-80 Gy, including conventional and moderate hypo-fractionated treatments. Rectal toxicity was scored using LENT/SOMA, a minimum 2-year follow up was considered. We chose to validate the model published by Rancati et al for predicting chronic FI, developed on a 3-dimensional conformal radiation therapy (3DCRT) population. It considered a longitudinal endpoint defined as the average toxicity grade during the follow up. This continuous endpoint was dichotomized using a cut-off value of mean FI grade >1. The model included mean rectal dose (Dmean), previous diseases of the colon (COLO) and previous abdominal surgery (SURG). Doses were corrected to 2 Gy/fraction using the linear-quadratic model and applying alpha/beta ratio = 4.8 Gy. RESULTS: 228 patients constituted the validation population. A mean FI grade >1 was scored in 25 patients (11%). Logistic regression confirmed risk factors reported in the literature, with similar odds ratios (ORs) for Dmean (1.04 ± 0.03 vs 1.06 ± 0.04) and SURG (1.9 ± 1.7 vs 1.6 ± 1.45); COLO was not confirmed. Consequently, the predictive models including Dmean/Dmean + SURG were evaluated using calibration plots. Both showed a clear discriminative trend, but the absolute observed toxicity rates were underestimated (ie, absolute predicted rates were always lower than corresponding absolute observed rates). This result was consistent with an unexpected effect of hypofractionation (OR = 2.20, conventional = 8.1% vs hypofractionated = 17.4%) beyond the standard correction using linear-quadratic model. Nevertheless, the FI rate in the conventionally treated group was almost double the rate observed in the previously studied cohort (4.3% vs 8.1%). CONCLUSIONS: The study confirms previously published results indicating that abdominal surgery and rectal mean dose are risk factors for late FI. Calibration plots highlight a possible role of hypofractionation beyond linear-quadratic correction.
Asunto(s)
Incontinencia Fecal/etiología , Neoplasias de la Próstata/radioterapia , Radioterapia de Intensidad Modulada/efectos adversos , Determinación de Punto Final , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Pronóstico , Dosificación Radioterapéutica , Reproducibilidad de los Resultados , Medición de Riesgo , Factores de TiempoRESUMEN
BACKGROUND AND PURPOSE: Intestinal toxicity is commonly experienced during whole-pelvis intensity-modulated radiotherapy (WPRT) for prostate cancer. The aim of the current study was to assess bowel dose-volume relationships for acute patient-reported intestinal symptoms of patients treated with WPRT for prostate cancer. MATERIALS AND METHODS: Complete data of 206 patients were available; the median dose to pelvic nodes was 51.8Gy (range 50.4-54.4, 1.7-2Gy/fr). Intestinal symptoms were assessed as changes in the Inflammatory Bowel Disease Questionnaire scores relative to the Bowel Domain (IBDQ-B) between baseline and radiotherapy mid-point/end. The 25th percentiles of the most severe worsening from baseline (ΔIBDQ-B) were set as end-points. The impact of bowel loops and sigmoid colon dose-volume/surface parameters as well as selected clinical parameters were investigated using multivariate logistic regression. RESULTS: Analyses were focused on the four questions showing a median ΔIBDQ-B>0. No dose volume/surface parameters were predictive, other than ΔIBDQ5≥3 (loose stools): when grouping patients according to bowel DVHs (high risk: V20>470cc, V30>245cc, V42>110cc; low risk: all the remaining patients), a two-variable model including high-risk DVH-shape (OR: 9.3) and age (protective, OR: 0.94) was assessed. The model showed good calibration (slope: 1.003, R2=0.92) and was found to be robust after bootstrap-based internal validation. CONCLUSIONS: Constraining the bowel loops may reduce the risk of loose stools. The risk is higher for younger patients.
Asunto(s)
Enfermedades Intestinales/etiología , Intestinos/efectos de la radiación , Traumatismos por Radiación/etiología , Anciano , Anciano de 80 o más Años , Diarrea/diagnóstico , Diarrea/etiología , Relación Dosis-Respuesta en la Radiación , Humanos , Enfermedades Intestinales/diagnóstico , Modelos Logísticos , Masculino , Persona de Mediana Edad , Medición de Resultados Informados por el Paciente , Pelvis/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Traumatismos por Radiación/diagnóstico , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/efectos adversos , Encuestas y CuestionariosRESUMEN
BACKGROUND: The aim of this paper was to analyze, retrospectively, in prostate cancer patients treated in our Centre with external beam radiotherapy, the prognostic factors and their impact on the outcome in terms of cancer-specific survival (CSS), biochemical disease-free survival (BDFS) and clinical disease-free survival (CDFS). METHODS: From October 1999 and March 2012, 1080 patients were treated with radiotherapy at our Institution: 87% of them were classified as ≤cT2, 83% had a Gleason Score (GS) ≤7, their mean of iPSA was 18 ng/mL, and the rate of clinical positive nodes was 1%. The mean follow-up was 81 months. RESULTS: The statistically significant prognostic factors for all groups of patients at both, univariate and multivariate analysis, were the GS and the iPSA. In intermediate- and high- or very-high-risk patients at multivariate analysis other prognostic factors for CSS were positive nodes on computed tomography (CT) scan and rectal preparation during the treatment; for BDFS, the prognostic factors were patient risk classification, positive lymph nodes on CT scan and rectal/bladder preparation; for CDFS, the prognostic factors were the number of positive core on biopsy (P=0.003), positive lymph nodes on CT scan, and radiotherapy (RT) dose. In high/very-high risk patient group at multivariate analysis other prognostic factors for CSS were clinical/radiological stage and RT dose, for BDFS they were adjuvant hormone therapy, clinical/radiological stage, and RT dose >77.7 Gy, and for CDFS they were clinical/radiological stage and RT dose >77.7 Gy. CONCLUSIONS: The results of this study confirm the prognostic factors described in the recent literature, with the addition of rectal/bladder preparation, generally known for its effect on toxicity but not yet on outcome.
Asunto(s)
Neoplasias de la Próstata/radioterapia , Dosificación Radioterapéutica , Anciano , Anciano de 80 o más Años , Biopsia con Aguja Gruesa , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Humanos , Calicreínas/sangre , Estimación de Kaplan-Meier , Metástasis Linfática , Masculino , Persona de Mediana Edad , Análisis Multivariante , Clasificación del Tumor , Modelos de Riesgos Proporcionales , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/patología , Radioterapia/efectos adversos , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
The use of imaging to maximize precision and accuracy throughout the entire process of radiation therapy (RT) delivery has been called "Image-guided RT" (IGRT). RT has long been image guided: in fact, historically, the portal films and later electronic megavoltage images represented an early form of IGRT. A broad range of IGRT modalities is now available and adopted. The target location may be defined for each treatment fraction by several methods by localizing surrogates, including implanted fiducial markers, external surface markers or anatomical features (through planar imaging, fluoroscopy, KV or MV computed tomography, magnetic resonance imaging, ultrasound and X-ray imaging, electromagnetic localization, optical surface imaging, etc.). The aim of the present review is to define practical recommendations for IGRT.
Asunto(s)
Neoplasias/radioterapia , Radioterapia Guiada por Imagen , Marcadores Fiduciales , Humanos , Italia , Radiometría , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por ComputadorRESUMEN
OBJECTIVE: To analyze the prevalence of cardiovascular disease (CVD) and osteoporosis in patients treated with androgen deprivation therapy (ADT) for prostate cancer (PCa) but not adherent to European Association of Urology (EAU) guidelines. MATERIALS AND METHODS: The CHOosIng Treatment for Prostate CanCEr (CHOICE) study was an Italian multicenter, cross-sectional study conducted from December 2010 to January 2012. A total of 1386 patients treated with ADT for PCa (first prescription or renewal of ADT) were selected. According to EAU guidelines, the cohort was categorized in discordant ADT (Group A) and concordant ADT (Group B). The prevalence of CVD and osteoporosis after ADT was recorded. RESULTS: The final cohort included 1075 patients. According to EAU guidelines adherence, 285 (26.51%) and 790 (73.49%) were considered discordant and concordant, respectively. The proportion of men with Charlson Comorbidity Index > 2 at baseline was statistically similar in Group A (81.8%) compared to Group B (80.8%) (P = .96). The number of complications reported at enrollment was as follows: cardiovascular in 351 (32.7%), endocrine in 166 (15.4%), sexual in 498 (46.3%), osteoporosis in 181 (16.8%), and gynecomastia in 274 (25.5%) subjects. At the multivariate logistic regression analysis adjusted for confounding factors, discordant ADT was associated with greater risk of cardiovascular complications (odds ratio: 2.07; P < .01) and osteoporosis (odds ratio: 1.75; P = .04). CONCLUSION: About one-third of patients with PCa received inappropriate ADT and showed a greater risk of CVD and osteoporosis. These results could be useful for setting better policy strategies to limit the inappropriateness of ADT prescription.
Asunto(s)
Antagonistas de Andrógenos/administración & dosificación , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Hormona Liberadora de Gonadotropina/agonistas , Orquiectomía/efectos adversos , Osteoporosis/epidemiología , Osteoporosis/etiología , Neoplasias de la Próstata/terapia , Anciano , Anciano de 80 o más Años , Antagonistas de Andrógenos/efectos adversos , Estudios Transversales , Humanos , Masculino , PrevalenciaRESUMEN
PURPOSE: We focused the attention on radiation therapy practices about the gynecological malignancies in Piedmont, Liguria, and Valle d'Aosta to know the current treatment practice and to improve the quality of care. MATERIAL AND METHODS: We proposed a cognitive survey to evaluate the standard practice patterns for gynecological cancer management, adopted from 2012 to 2014 by radiotherapy (RT) centers with a large amount of gynecological cancer cases. There were three topics: 1. Taking care and multidisciplinary approach, 2. Radiotherapy treatment and brachytherapy, 3. Follow-up. RESULTS: Nineteen centers treated gynecological malignancies and 12 of these had a multidisciplinary dedicated team. Radiotherapy option has been used in all clinical setting: definitive, adjuvant, and palliative. In general, 1978 patients were treated. There were 834 brachytherapy (BRT) treatments. The fusion between diagnostic imaging (magnetic resonance imaging - MRI, positron emission tomography - PET) and computed tomography (CT) simulation was used for contouring in all centers. Conformal RT and intensity modulated radiation therapy (IMRT) were the most frequent techniques. The image guided radiation therapy (IGRT) was used in 10/19 centers. There were 8 active BRT centers. Brachytherapy was performed both with radical intent and as boost, mostly by HDR (6/8 centers). The doses for exclusive BRT were between 20 to 30 Gy. The doses for BRT boost were between 10 and 20 Gy. Four centers used CT-MRI compatible applicators but only one used MRI for planning. The BRT plans on vaginal cuff were still performed on traditional radiographies in 2 centers. The plan sum was evaluated in only 1 center. Only 1 center performed in vivo dosimetry. CONCLUSIONS: In the last three years, multidisciplinary approach, contouring, treatment techniques, doses, and control systems were similar in Liguria-Piedmont and Valle d'Aosta. However, the technology implementation didn't translate in a real treatment innovation so far.