RESUMEN
Bolus serves as a tissue equivalent material that shifts the 95-100% isodose line towards the skin and subcutaneous tissue. The need for bolus for all breast cancer patients planned for postmastectomy radiation therapy (PMRT) has been questioned. The work was initiated by the faculty of the European SocieTy for Radiotherapy & Oncology (ESTRO) breast cancer courses and represents a multidisciplinary international breast cancer expert collaboration to optimize PMRT. Due to the lack of randomised trials evaluating the benefits of bolus, we designed a stepwise project to evaluate the existing evidence about the use of bolus in the setting of PMRT to achieve an international consensus for the indications of bolus in PMRT, based on the Delphi method.
Asunto(s)
Neoplasias de la Mama , Mastectomía , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Consenso , Técnica Delphi , Femenino , Humanos , Radioterapia AdyuvanteRESUMEN
PURPOSE: Post mastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and breast cancer mortality for selected patients. Bolus overcomes the skin-sparing effect of external-beam radiotherapy, ensuring adequate dose to superficial regions at risk of local recurrence (LR). This systematic review summarizes the current evidence regarding the impact of bolus on LR and acute toxicity in the setting of PMRT. RESULTS: 27 studies were included. The use of bolus led to higher rates of acute grade 3 radiation dermatitis (pooled rates of 9.6% with bolus vs. 1.2% without). Pooled crude LR rates from thirteen studies (n = 3756) were similar with (3.5%) and without (3.6%) bolus. CONCLUSIONS: Bolus may be indicated in cases with a high risk of LR in the skin, but seems not to be necessary for all patients. Further work is needed to define the role of bolus in PMRT.
Asunto(s)
Neoplasias de la Mama , Radiodermatitis , Neoplasias de la Mama/patología , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Femenino , Humanos , Mastectomía , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Radioterapia Adyuvante/efectos adversosRESUMEN
PURPOSE: This study evaluated long-term, population-based, breast cancer-specific outcomes in patients treated with radiation therapy (RT) to the breast/chest wall plus regional nodes using hypofractionated (HF) (40-42.5 Gy/16 fractions) versus conventionally fractionated (CF) regimens (50-50.4 Gy/25-28 fractions). METHODS AND MATERIALS: A prospective provincial database was used to identify patients with lymph node-positive breast cancer treated with curative-intent breast/chest wall + regional nodal RT from 1998 to 2010. The effect of RT fractionation on locoregional recurrence-free survival (LRRFS), distant recurrence-free survival (DRFS), and breast cancer-specific survival (BCSS) was assessed for the entire cohort and for high-risk subgroups: grade 3, ER-/HER2-, HER2+, and ≥4 positive nodes. Multivariable analysis and 2:1 case-match comparison of HF versus CF were also performed. RESULTS: A total of 5487 patients met the inclusion criteria (4006 HF and 1481 CF). Median age was 55 years, and median follow-up was 12.7 years. On multivariable analysis, no statistically significant differences were identified in 10-year LRRFS (hazard ratio [HR] 0.87; 95% confidence interval [CI], 0.59-1.27; P = .46), DRFS (HR 0.90; 95% CI, 0.76-1.06; P = .19), or BCSS (HR 0.92; 95% CI, 0.76-1.10; P = .36) between the HF and CF cohorts. There was no statistical difference in breast cancer-specific outcomes in the high-risk subgroups. On analysis of 2962 HF cases matched to 1481 CF controls, no statistical difference was observed in LRRFS (HR 0.98; 95% CI, 0.71-1.33; P = .87), DRFS (HR 0.97; 95% CI, 0.85-1.11; P = .68), or BCSS (HR 1.00; 95% CI, 0.87-1.16; P = .92). CONCLUSIONS: This large, population-based analysis with long-term follow-up after locoregional RT demonstrated that modest HF provides similar breast cancer-specific outcomes compared with CF. HF is an effective option for patients with stage I to III breast cancer receiving nodal RT.
Asunto(s)
Neoplasias de la Mama/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/química , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Intervalos de Confianza , Bases de Datos Factuales , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Irradiación Linfática , Metástasis Linfática , Persona de Mediana Edad , Análisis Multivariante , Recurrencia Local de Neoplasia , Modelos de Riesgos Proporcionales , Hipofraccionamiento de la Dosis de Radiación , Radioterapia Adyuvante/métodos , Estudios Retrospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Whole breast irradiation delivered once per day over 3-5 weeks after breast conserving surgery reduces local recurrence with good cosmetic results. Accelerated partial breast irradiation (APBI) delivered over 1 week to the tumour bed was developed to provide a more convenient treatment. In this trial, we investigated if external beam APBI was non-inferior to whole breast irradiation. METHODS: We did this multicentre, randomised, non-inferiority trial in 33 cancer centres in Canada, Australia and New Zealand. Women aged 40 years or older with ductal carcinoma in situ or node-negative breast cancer treated by breast conserving surgery were randomly assigned (1:1) to receive either external beam APBI (38·5 Gy in ten fractions delivered twice per day over 5-8 days) or whole breast irradiation (42·5 Gy in 16 fractions once per day over 21 days, or 50 Gy in 25 fractions once per day over 35 days). Patients and clinicans were not masked to treatment assignment. The primary outcome was ipsilateral breast tumour recurrence (IBTR), analysed by intention to treat. The trial was designed on the basis of an expected 5 year IBTR rate of 1·5% in the whole breast irradiation group with 85% power to exclude a 1·5% increase in the APBI group; non-inferiority was shown if the upper limit of the two-sided 90% CI for the IBTR hazard ratio (HR) was less than 2·02. This trial is registered with ClinicalTrials.gov, NCT00282035. FINDINGS: Between Feb 7, 2006, and July 15, 2011, we enrolled 2135 women. 1070 were randomly assigned to receive APBI and 1065 were assigned to receive whole breast irradiation. Six patients in the APBI group withdrew before treatment, four more did not receive radiotherapy, and 16 patients received whole breast irradiation. In the whole breast irradiation group, 16 patients withdrew, and two more did not receive radiotherapy. In the APBI group, a further 14 patients were lost to follow-up and nine patients withdrew during the follow-up period. In the whole breast irradiation group, 20 patients were lost to follow-up and 35 withdrew during follow-up. Median follow-up was 8·6 years (IQR 7·3-9·9). The 8-year cumulative rates of IBTR were 3·0% (95% CI 1·9-4·0) in the APBI group and 2·8% (1·8-3·9) in the whole breast irradiation group. The HR for APBI versus whole breast radiation was 1·27 (90% CI 0·84-1·91). Acute radiation toxicity (grade ≥2, within 3 months of radiotherapy start) occurred less frequently in patients treated with APBI (300 [28%] of 1070 patients) than whole breast irradiation (484 [45%] of 1065 patients, p<0·0001). Late radiation toxicity (grade ≥2, later than 3 months) was more common in patients treated with APBI (346 [32%] of 1070 patients) than whole breast irradiation (142 [13%] of 1065 patients; p<0·0001). Adverse cosmesis (defined as fair or poor) was more common in patients treated with APBI than in those treated by whole breast irradiation at 3 years (absolute difference, 11·3%, 95% CI 7·5-15·0), 5 years (16·5%, 12·5-20·4), and 7 years (17·7%, 12·9-22·3). INTERPRETATION: External beam APBI was non-inferior to whole breast irradiation in preventing IBTR. Although less acute toxicity was observed, the regimen used was associated with an increase in moderate late toxicity and adverse cosmesis, which might be related to the twice per day treatment. Other approaches, such as treatment once per day, might not adversely affect cosmesis and should be studied. FUNDING: Canadian Institutes for Health Research and Canadian Breast Cancer Research Alliance.
Asunto(s)
Braquiterapia/métodos , Neoplasias de la Mama/radioterapia , Carcinoma in Situ/radioterapia , Carcinoma Ductal de Mama/radioterapia , Anciano , Australia , Neoplasias de la Mama/cirugía , Canadá , Carcinoma in Situ/patología , Carcinoma in Situ/cirugía , Carcinoma Ductal de Mama/cirugía , Femenino , Humanos , Mastectomía Segmentaria , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia/prevención & control , Nueva Zelanda , Pronóstico , Tasa de SupervivenciaRESUMEN
PURPOSE: The Cancer and Leukemia Group B (CALGB) 9343 trial randomized elderly women with estrogen receptor-positive, stage 1 breast cancer to receive either hormone therapy (HT) or HT and radiation therapy (HT-RT) after lumpectomy and showed no difference in survival. After this publication, a practice guideline made HT alone a standard treatment option in British Columbia. The subsequent population-based pattern of practice was studied. METHODS AND MATERIALS: All women aged 70 to 79 years, referred after lumpectomy from 1999 to 2009, with stage 1, estrogen receptor-positive breast cancer were identified. The use of adjuvant HT or HT-RT was evaluated in 2 eras: before (1999-2003) and after (2005-2009) the CALGB publication. The proportion receiving each treatment in these eras was determined. Kaplan-Meier analyses with Cox regression were used for survival endpoints. The Fine and Gray method was used with non-breast cancer death as a competing risk for event-free survival. The Charlson score was used to quantify comorbidity. Adherence was defined as dispensation of 80% of prescribed HT. RESULTS: HT-RT was used in 91% of patients before (n=319) and 89% of patients after (n=403) the CALGB publication (P=.4). In the HT-alone group, the rate of HT adherence was 75% at 1 year and 55% at 4 years. The 10-year locoregional recurrence-free survival rate was 98% with HT-RT and 90% with HT alone (P=.01), whereas the 10-year breast cancer-specific survival rate was 96% with HT-RT and 95% with HT alone (P=.2). Patients with grade 3 histology or lymphovascular invasion were more likely to have low event-free survival. On multivariate analysis, treatment type did not predict overall survival (P=.3). CONCLUSIONS: Our patient outcomes closely matched those of the CALGB trial, suggesting that its results are generalizable to a population of elderly breast cancer patients with typical HT adherence. The CALGB trial results, as well as the resulting practice guideline, did not change the use of adjuvant HT-RT in our population-based cancer program.
Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/radioterapia , Anciano , Neoplasias de la Mama/química , Neoplasias de la Mama/patología , Colombia Británica , Terapia Combinada/métodos , Terapia Combinada/estadística & datos numéricos , Supervivencia sin Enfermedad , Fraccionamiento de la Dosis de Radiación , Femenino , Humanos , Estimación de Kaplan-Meier , Mastectomía Segmentaria/métodos , Mastectomía Segmentaria/estadística & datos numéricos , Guías de Práctica Clínica como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Regresión , Estudios Retrospectivos , Tasa de Supervivencia , Factores de TiempoRESUMEN
PURPOSE: There is controversy about whether patients with synchronous bilateral breast cancer (SBBC) have similar or worse outcomes compared with patients with unilateral breast cancer. The purpose of this study was to determine whether survival outcomes for patients with SBBC can be estimated from the characteristics of their individual cancers. PATIENTS AND METHODS: Patients had invasive breast cancer, without metastases or inflammatory disease, diagnosed in British Columbia between 1989 and 2000. There were 207 cases with SBBC (diagnosed ≤ 2 months apart) and 15,497 with unilateral breast cancer. By using 10-year breast cancer-specific survival (BCSS) estimates, the higher-risk cancer of each SBBC case was determined and matched with three breast cancers from the unilateral cohort to select 621 high-risk matches. The priority sequence of matching the prognostic and predictive variables was positive lymph node number, primary tumor size, age, grade, lymphovascular invasion, estrogen receptor status, local therapy used, margin status, treating clinic, diagnosis year, and type of systemic therapy used. RESULTS: With a median follow-up of 10.2 years, the overall 10-year BCSS was significantly higher for the unilateral cohort (81%; 95% CI, 81% to 82%) than for the SBBC cases (71%; 95% CI, 63% to 77%). The SBBC cases had significantly higher mean age and stage at presentation. The 10-year BCSS was 74% (95% CI, 69% to 77%) for the high-risk matches. CONCLUSION: BCSS was not significantly different between the SBBC cases and their high-risk matches.
Asunto(s)
Neoplasias de la Mama/mortalidad , Neoplasias Primarias Múltiples/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Estudios de Cohortes , Femenino , Humanos , Persona de Mediana Edad , Estadificación de NeoplasiasRESUMEN
PURPOSE: Volumetric modulated arc therapy (VMAT), the predecessor to Varian's RapidArc, is a novel extension of intensity-modulated radiotherapy (IMRT) wherein the dose is delivered in a single gantry rotation while the multileaf collimator leaves are in motion. Leaf positions and the weights of field samples along the arc are directly optimized, and a variable dose rate is used. This planning study compared seven-field coplanar IMRT (cIMRT) with VMAT for high-grade gliomas that had planning target volumes (PTVs) overlapping organs at risk (OARs). METHODS AND MATERIALS: 10 previously treated patients were replanned to 60 Gy in 30 fractions with cIMRT and VMAT using the following planning objectives: 98% of PTV covered by 95% isodose without violating OAR and hotspot dose constraints. Mean OAR doses were maximally decreased without reducing PTV coverage or violating hotspot constraints. We compared dose-volume histogram data, monitor units, and treatment times. RESULTS: There was equivalent PTV coverage, homogeneity, and conformality. VMAT significantly reduced maximum and mean retinal, lens, and contralateral optic nerve doses compared with IMRT (p < 0.05). Brainstem, chiasm, and ipsilateral optic nerve doses were similar. For 2-Gy fractions, mean monitor units were as follows: cIMRT = 789 +/- 112 and VMAT = 363 +/- 45 (relative reduction 54%, p = 0.002), and mean treatment times (min) were as follows: cIMRT = 5.1 +/- 0.4 and VMAT = 1.8 +/- 0.1 (relative reduction 65%, p = 0.002). CONCLUSIONS: Compared with cIMRT, VMAT achieved equal or better PTV coverage and OAR sparing while using fewer monitor units and less time to treat high-grade gliomas.
Asunto(s)
Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Traumatismos por Radiación/prevención & control , Radioterapia de Intensidad Modulada/métodos , Neoplasias Encefálicas/patología , Tronco Encefálico/efectos de la radiación , Fraccionamiento de la Dosis de Radiación , Femenino , Glioma/patología , Humanos , Cristalino/efectos de la radiación , Masculino , Nervio Óptico/efectos de la radiación , Retina/efectos de la radiación , Carga TumoralRESUMEN
PURPOSE: To determine the reduction of prostate motion during a typical radiotherapy (RT) fraction from a bowel regimen comprising an antiflatulent diet and daily milk of magnesia. METHODS AND MATERIALS: Forty-two patients with T1c-T2c prostate cancer voided the bladder and rectum before three cinematic magnetic resonance imaging scans obtained every 9 s for 9 min in a vacuum immobilization device. The MRIs were at baseline without bowel regimen (MRI-BL), before CT planning with bowel regimen (MRI-CT), and before a randomly assigned RT fraction (1-42) with bowel regimen (MRI-RT). A single observer tracked displacement of the posterior midpoint (PM) of the prostate. The primary endpoints were comparisons of the proportion of time that the PM was displaced >3 mm (PTPM3) from its initial position, and the secondary endpoints were comparisons of the reduction of initial rectal area, with and without the bowel regimen. RESULTS: The mean rectal area was: 13.5 cm(2) at MRI-BL, 12.7 cm(2) at MRI-CT, and 12.3 cm(2) at MRI-RT (MRI-BL vs. MRI-CT, p = 0.11; MRI-BL vs. MRI-CT, p = 0.07). Moving rectal gas alone (56%) and moving gas and stool (18%) caused 74% of intrafraction prostate motion. The PTPM3 was 11.3% at MRI-BL, 4.8% at MRI-CT, and 12.0% at MRI-RT (MRI-BL vs. MRI-CT, p = 0.12; MRI-BL vs. MRI-RT, p = 0.89). CONCLUSION: For subjects voiding their rectum before imaging, an antiflatulent diet and milk of magnesia laxative did not significantly reduce initial rectal area or intrafraction prostate motion.
Asunto(s)
Flatulencia/dietoterapia , Laxativos/uso terapéutico , Óxido de Magnesio/uso terapéutico , Imagen por Resonancia Cinemagnética/métodos , Movimiento , Próstata , Neoplasias de la Próstata/radioterapia , Anciano , Defecación , Heces , Gases , Humanos , Masculino , Persona de Mediana Edad , Recto/anatomía & histología , Recto/fisiología , MicciónRESUMEN
Surgical clips were investigated for partial breast image-guided radiotherapy (IGRT). Small titanium clips were insufficiently well visualised. Medium tantalum clips were best for megavoltage IGRT and small tantalum clips were best for floor mounted kilovoltage IGRT (ExacTrac). Both small tantalum and medium titanium clips were suitable for isocentric kilovoltage IGRT.
Asunto(s)
Neoplasias de la Mama/radioterapia , Fantasmas de Imagen , Instrumentos Quirúrgicos , Artefactos , Humanos , Modelos Logísticos , Tantalio , Titanio , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Evaluate the accuracy and the sensitivity to contour variation and model size of a finite element model-based deformable registration algorithm for the prostate. METHODS AND MATERIALS: Two magnetic resonance images (MRIs) were obtained for 21 prostate patients with three implanted markers. A single observer contoured the prostate and markers and performed blinded recontouring of the first MRI. A biomechanical-model based deformable registration algorithm, MORFEUS, was applied to each dataset pair, deforming the second image (B) to the first image (A). The residual error was calculated by comparing the center of mass (COM) of the markers with the predicted COM. Sensitivity to contour variation was calculated by deforming B to the repeat contour of A (A2). The sensitivity to the model size was calculated by reducing the number of nodes (B', A', A2') and repeating the analysis. RESULTS: The average residual error of the registration for B to A and B to A2 was 0.22 cm (SD: 0.08 cm) and 0.24 cm (SD: 0.09 cm), respectively. The average residual error of the registration of B' to A' and B' to A2' was 0.22 cm (SD: 0.10 cm) and 0.25 cm (SD: 0.10 cm), respectively. The average time to run MORFEUS on the standard and reduced model was 3606 s (SD: 7788 s) and 56 s (SD: 16 s), respectively. CONCLUSIONS: The accuracy of the algorithm, equal to the image voxel size, is not affected by intraobserver contour variability or model size. Reducing the model size significantly increases algorithm efficiency.
Asunto(s)
Algoritmos , Análisis de Elementos Finitos , Neoplasias de la Próstata/patología , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , MasculinoRESUMEN
PURPOSE: The aim of this study is to develop a surface-based deformable image registration strategy and to assess the accuracy of the system for the integration of multimodality imaging, image-guided radiation therapy, and assessment of geometrical change during and after therapy. METHODS AND MATERIALS: A surface-model-based deformable image registration system has been developed that enables quantitative description of geometrical change in multimodal images with high computational efficiency. Based on the deformation of organ surfaces, a volumetric deformation field is derived using different volumetric elasticity models as alternatives to finite-element modeling. RESULTS: The accuracy of the system was assessed both visually and quantitatively by tracking naturally occurring landmarks (bronchial bifurcations in the lung, vessel bifurcations in the liver, implanted gold markers in the prostate). The maximum displacements for lung, liver and prostate were 5.3 cm, 3.2 cm, and 0.6 cm respectively. The largest registration error (direction, mean +/- SD) for lung, liver and prostate were (inferior-superior, -0.21 +/- 0.38 cm), (anterior-posterior, -0.09 +/- 0.34 cm), and (left-right, 0.04 +/- 0.38 cm) respectively, which was within the image resolution regardless of the deformation model. The computation time (2.7 GHz Intel Xeon) was on the order of seconds (e.g., 10 s for 2 prostate datasets), and deformed axial images could be viewed at interactive speed (less than 1 s for 512 x 512 voxels). CONCLUSIONS: Surface-based deformable image registration enables the quantification of geometrical change in normal tissue and tumor with acceptable accuracy and speed.
Asunto(s)
Neoplasias Hepáticas/diagnóstico por imagen , Hígado/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Próstata/diagnóstico por imagen , Planificación de la Radioterapia Asistida por Computador/métodos , Femenino , Humanos , Riñón/diagnóstico por imagen , Neoplasias Hepáticas/radioterapia , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Masculino , Modelos Anatómicos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/radioterapia , Prótesis e Implantes , Radiografía , Estómago/diagnóstico por imagen , Factores de TiempoRESUMEN
PURPOSE: To describe prostate deformation during radiotherapy and determine the margins required to account for prostate deformation after setup to intraprostatic fiducial markers (FM). METHODS AND MATERIALS: Twenty-five patients with T1c-T2c prostate cancer had three gold FMs implanted. The patients presented with a full bladder and empty rectum for two axial magnetic resonance imaging (MRI) scans using a gradient recalled echo (GRE) sequence capable of imaging the FMs. The MRIs were done at the time of radiotherapy (RT) planning and a randomly assigned fraction. A single observer contoured the prostate surfaces. They were entered into a finite element model and aligned using the centroid of the three FMs. RESULTS: During RT, the prostate volume decreased by 0.5%/fraction (p = 0.03) and the FMs in-migrated by 0.05 mm/fraction (p < 0.05). Prostate deformation was unrelated to differential bladder and bowel filling, but was related to a transurethral resection of the prostate (TURP) (p = 0.003). The standard deviation for systematic uncertainty of prostate surface contouring was 0.8 mm and for FM centroid localization was 0.4 mm. The standard deviation of random interfraction prostate deformation was 1.5 mm and for FM centroid variability was 1.1 mm. These uncertainties from prostate deformation can be incorporated into a margin recipe to determine the total margins required for RT. CONCLUSIONS: During RT, the prostate exhibited: volume decrease, deformation, and in-migration of FMs. Patients with TURPs were prone to prostate deformation.
Asunto(s)
Oro , Imagen por Resonancia Magnética/métodos , Próstata/patología , Neoplasias de la Próstata/patología , Prótesis e Implantes , Anciano , Análisis de Elementos Finitos , Humanos , Masculino , Persona de Mediana Edad , Movimiento , Próstata/cirugía , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/cirugía , Reproducibilidad de los Resultados , Resección Transuretral de la PróstataRESUMEN
PURPOSE: Inconsistencies in contouring target structures can undermine the precision of conformal radiation therapy (RT) planning and compromise the validity of clinical trial results. This study evaluated the impact of guidelines on consistency in target volume contouring for partial breast RT planning. METHODS AND MATERIALS: Guidelines for target volume definition for partial breast radiation therapy (PBRT) planning were developed by members of the steering committee for a pilot trial of PBRT using conformal external beam planning. In phase 1, delineation of the breast seroma in 5 early-stage breast cancer patients was independently performed by a "trained" cohort of four radiation oncologists who were provided with these guidelines and an "untrained" cohort of four radiation oncologists who contoured without guidelines. Using automated planning software, the seroma target volume (STV) was expanded into a clinical target volume (CTV) and planning target volume (PTV) for each oncologist. Means and standard deviations were calculated, and two-tailed t tests were used to assess differences between the "trained" and "untrained" cohorts. In phase 2, all eight radiation oncologists were provided with the same contouring guidelines, and were asked to delineate the seroma in five new cases. Data were again analyzed to evaluate consistency between the two cohorts. RESULTS: The "untrained" cohort contoured larger seroma volumes and had larger CTVs and PTVs compared with the "trained" cohort in three of five cases. When seroma contouring was performed after review of contouring guidelines, the differences in the STVs, CTVs, and PTVs were no longer statistically significant. CONCLUSION: Guidelines can improve consistency among radiation oncologists performing target volume delineation for PBRT planning.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Guías de Práctica Clínica como Asunto , Planificación de la Radioterapia Asistida por Computador/normas , Seroma/diagnóstico por imagen , Neoplasias de la Mama/radioterapia , Femenino , Humanos , Radiografía , Radioterapia ConformacionalRESUMEN
The clinical heterogeneity of intermediate-risk prostate carcinoma presents a challenge to urologic oncology in terms of prognosis and management. There is controversy regarding whether patients with intermediate-risk prostate carcinoma should be treated with dose-escalated external beam radiotherapy (EBRT) (e.g., doses > 74 gray [Gy]), or conventional-dose EBRT (e.g., doses < 74 Gy) combined with androgen deprivation (AD). Data for this review were identified through searches for articles in MEDLINE and in conference proceedings, indexed from 1966 to 2004. Currently, the intermediate-risk prostate carcinoma grouping is defined on the basis of prostate-specific antigen (PSA), tumor classification (T classification), and Gleason score. Emerging evidence suggests that additional prognostic information may be derived from the percentage of positive core needle biopsies at the time of diagnosis and/or from the pretreatment PSA doubling time. Novel prognostic biomarkers include protein expression relating to cell cycle control, cell death, DNA repair, and intracellular signal transduction. Preclinical data support dose escalation or combined AD with radiation as a means to increase prostate carcinoma cell kill. There is Level I evidence that patients with intermediate-risk prostate carcinoma benefit from dose-escalated EBRT or AD plus conventional-dose EBRT. However, clinical evidence is lacking to support the uniform use of AD plus dose-escalated EBRT. Patients in the intermediate-risk group should be entered into well designed, randomized clinical trials of dose-escalated EBRT and AD with sufficient power to address biochemical failure and cause-specific survival endpoints. These studies should be stratified by novel prognostic markers and accompanied by strong translational endpoints to address clinical heterogeneity and to allow for individualized treatment.
Asunto(s)
Neoplasias de la Próstata/radioterapia , Ensayos Clínicos como Asunto , Terapia Combinada , Humanos , Masculino , Pronóstico , Dosificación Radioterapéutica , RiesgoRESUMEN
PURPOSE: To determine the rate of change in the cross-sectional area of the masticatory muscles after radiotherapy. METHODS AND MATERIALS: Eligible patients had undergone unilateral radiotherapy between 1993 and 2000 and had a baseline CT scan, a comparable follow-up CT scan a minimum of 1 year later, and no recurrence of cancer. Fourteen patients had their CT series scanned into digital image files. Two anatomically selected CT slices were bisected by the midline sagittal plane and stored under randomly assigned file names. Three observers measured the masseter and medial pterygoid areas on two occasions. RESULTS: The intraobserver reliability of the muscle area measurements was 96.3% for the masseter and 97.1% for the medial pterygoid. The interobserver reliability of the muscle area measurements was 96.7% for the masseter and 96.3% for the medial pterygoid. On the treated side, the muscles received a median dose of 56 Gy (range 47-63) in 2.0-0.4-Gy fractions. With a median follow-up of 2.9 years (range 1-7.6), mixed-effects regression analysis demonstrated a significant area of reduction of -0.17 cm(2)/y (p = 0.0001) for the masseter and -0.13 cm(2)/y (p = 0.001) for the medial pterygoid. The controlled rate of muscle atrophy was 3.9%/y (95% confidence interval 1.4-6.4) for the masseter and 2.3%/y (95% confidence interval -0.6 to 5.1) for the medial pterygoid. CONCLUSION: Standard therapeutic radiation doses appear to cause significant masticatory muscle atrophy.