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1.
Radiat Oncol ; 18(1): 54, 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36941643

RESUMEN

BACKGROUND: Utero-vaginal brachytherapy (BT) is an irreplaceable care component for the curative treatment of locally advanced cervix cancer (LACC). Magnetic Resonance Imaging (MRI)-image guided adaptive BT (IGABT) using the GYN-GEC-ESTRO EMBRACE guidelines is the international care standard. Usually following chemo-radiation therapy (CRT), IGABT has high proven utility in LACC but requires significant health system resources. Timely access was disrupted by the COVID-19 pandemic which challenged us to re-design our established IGABT care pathway. METHODS: From April 2020 consecutive patients with LACC were enrolled after CRT in a single arm exploratory non-inferiority study of a modified IGABT (mIGABT) protocol. This delivered an iso-effective IGABT dose (39.3 Gy: EQD2: α/ß10Gy concept) over a 24-h period during a single overnight hospitalisation. RESULTS: Fourteen LACC patients received mIGABT from April 2020 to March 2022. Median age was 62.5 years (37-82 years). LACC histology was primary squamous (9/14) or adeno-carcinoma (5/14). International Federation of Gynaecology and Obstetrics (FIGO) 2018 stages ranged from IB1/2 (N = 3), IIA1/IIB (5), IIIB (2), IIIC1/2 (4) with mean ± standard deviation (SD) gross tumour volume-at-diagnosis (GTV_D) of 37.7 cc ± 71.6 cc. All patients achieved complete metabolic, clinical, and cytologic cancer response with CRT and IGABT. High-risk HPV was cleared by 6-months. Complete MRI-defined cancer response before mIGABT (GTV_Fx1) was seen in 77% of cases (10/13). Only two women developed metastatic disease and one died at 12-months; 13 patients were alive without cancer at mean 20.3 ± 7.2 months follow-up. Actuarial 2-year overall survival was 93%. Compared with our pre-COVID IGABT program, overall mIGABT cost-saving in this cohort was USD 22,866. Prescribed dose covered at least 90% (D90) of the entire cervix and any residual cancer at time of BT (HRCTV_D90: high-risk clinical target volume) with 3-fractions of 8.5 Gy delivered over 24-h (22.8 ± 1.7 h). Total treatment time including CRT was 38 days. The mIGABT schedule was well tolerated and the entire cohort met EMBRACE recommended (EQD2: α/ß10Gy) combined HRCTV_D90 coverage of 87.5 ± 3.7 Gy. Similarly, organ-at-risk (OAR) median: interquartile range D2cc constraints (EQD2: α/ß3Gy) were EMBRACE compliant: bladder (65.9 Gy: 58.4-72.5 Gy), rectum (59.1 Gy: 55.7-61.8 Gy), and sigmoid colon (54.6 Gy: 50.3-58.9 Gy). ICRU recto-vaginal point dose was significantly higher (75.7 Gy) in our only case of severe (G4) pelvic toxicity. CONCLUSIONS: This study demonstrated the utility of mIGABT and VMAT CRT in a small cohort with LACC. Loco-regional control was achieved in all cases with minimal emergent toxicity. Single insertion mIGABT was logistically efficient, cost-saving, and patient-centric during the COVID-19 pandemic.


Asunto(s)
Braquiterapia , COVID-19 , Neoplasias del Cuello Uterino , Femenino , Humanos , Persona de Mediana Edad , Braquiterapia/métodos , Imagen por Resonancia Magnética , Pandemias , Dosificación Radioterapéutica , Resultado del Tratamiento , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Anciano de 80 o más Años
2.
Trials ; 24(1): 132, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36814310

RESUMEN

BACKGROUND: Deep inspiration breath hold (DIBH) reduces radiotherapy cardiac dose for left-sided breast cancer patients. The primary aim of the BRAVEHeart (Breast Radiotherapy Audio Visual Enhancement for sparing the Heart) trial is to assess the accuracy and usability of a novel device, Breathe Well, for DIBH guidance for left-sided breast cancer patients. Breathe Well will be compared to an adapted widely available monitoring system, the Real-time Position Management system (RPM). METHODS: BRAVEHeart is a single institution prospective randomised trial of two DIBH devices. BRAVEHeart will assess the DIBH accuracy for Breathe Well and RPM during left-sided breast cancer radiotherapy. After informed consent has been obtained, 40 patients will be randomised into two equal groups, the experimental arm (Breathe Well) and the control arm (RPM with in-house modification of an added patient screen). The primary hypothesis of BRAVEHeart is that the accuracy of Breathe Well in maintaining the position of the chest during DIBH is superior to the RPM system. Accuracy will be measured by comparing chest wall motion extracted from images acquired of the treatment field during breast radiotherapy for patients treated using the Breathe Well system and those using the RPM system. DISCUSSION: The Breathe Well device uses a depth camera to monitor the chest surface while the RPM system monitors a block on the patient's abdomen. The hypothesis of this trial is that the chest surface is a better surrogate for the internal chest wall motion used as a measure of treatment accuracy. The Breathe Well device aims to deliver an easy-to-use implementation of surface monitoring. The findings from the study will help inform the technology choice for other centres performing DIBH. TRIAL REGISTRATION: ClinicalTrials.gov NCT02881203 . Registered on 26 August 2016.


Asunto(s)
Neoplasias de la Mama , Neoplasias de Mama Unilaterales , Humanos , Femenino , Contencion de la Respiración , Neoplasias de Mama Unilaterales/radioterapia , Estudios Prospectivos , Corazón , Órganos en Riesgo
3.
Pract Radiat Oncol ; 12(3): e201-e206, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34619375

RESUMEN

PURPOSE: Stereotactic body radiation therapy (SBRT) is a recognized treatment for low- and intermediate-risk prostate cancer, with 36.25 Gy in 5 fractions the most commonly used regimen. We explored the preliminary efficacy, patient recorded toxicity, and decision regret in intermediate- and high-risk prostate cancer receiving SBRT with prostate-specific membrane antigen (PSMA)/magnetic resonance imaging (MRI) guided focal gross tumor volume boost to 45 Gy. METHODS AND MATERIALS: Between July 2015 and June 2019, 120 patients received SBRT across 2 institutions with a uniform protocol. All patients had fiducial markers and hydrogel, MRI and PSMA positron emission tomography (PET) scan. All patients received a questionnaire asking the degree of urinary, bowel, and sexual bother experienced at set time points, including questions about treatment choice and decision regret. RESULTS: One hundred twelve of 120 patients consented. Their median age was 72 years and median follow-up was 2.3 years. As per National Comprehensive Cancer Network guidelines, 78% had intermediate risk and 20% high risk. Androgen deprivation was combined with radiation in 6 patients. Most patients (74%) reported that receiving SBRT significantly influenced their choice of treatment. Five men (4%) expressed "quite a lot" (n = 4) or "very much" regret (n = 1) regarding their choice of treatment, while 89% expressed "no regret." Similar to pretreatment levels, "quite a lot" or "very much" urinary or bowel bother was expressed in 8% and 6% of patients, respectively. Two patients experienced nadir +2 biochemical failure, both found to have bone metastases. A third patient underwent PSMA PET at nadir +1.7 and had disease at the penile bulb, which was out of field. Three year estimated freedom from biochemical failure was 99% for intermediate and 85% for high-risk groups. CONCLUSIONS: We have demonstrated promising efficacy and low toxicity with PSMA/MRI-guided SBRT focal boost. Less than 5% of patients expressed significant decision regret for their choice of treatment.


Asunto(s)
Neoplasias de la Próstata , Radiocirugia , Anciano , Antagonistas de Andrógenos , Emociones , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Radiocirugia/efectos adversos , Radiocirugia/métodos
4.
J Med Radiat Sci ; 69(1): 75-84, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33955205

RESUMEN

INTRODUCTION: Until late 2018, standard of practice at the Northern Sydney Cancer Centre (NSCC) for breast and nodal treatment was a conformal mono-isocentric technique. A planning study comparing an existing mono-isocentric three-dimensional conformal radiotherapy (3D-CRT) planning technique to a hybrid intensity-modulated radiotherapy (hIMRT) approach for the whole breast and supraclavicular fossa (SCF) region was undertaken with the aim to improve plan quality by improving dose conformity/homogeneity across target volumes and reducing hotspots outside the target. METHODS: A cohort of 17 patients was retrospectively planned using the proposed hIMRT technique, keeping the same planning constraints as the original treated breast and SCF 3D-CRT plan and normalising the 3D-CRT plans to achieve minimum breast/SCF target coverage to compare organs at risk (OARs). Normal tissue index (NTI) and homogeneity index (HI) were compared for plan quality as well as for evaluating OARs. RESULTS: The hIMRT technique showed statistically significant improvements in NTI and HI, as well as improvement in maximum brachial plexus and thyroid doses. There was a negligible increase in maximum oesophagus dose which could be improved if used in optimisation. Other OAR doses in the irradiated region were comparable to the 3D-CRT plans, however maximum doses were reduced overall. CONCLUSION: The hIMRT planning technique maintained clinically acceptable doses to OARs and reduced normal tissue dose while maintaining equivalent dose coverage to breast and SCF planning target volumes with improved conformity and homogeneity. The reduction in maximum doses promotes a favourable toxicity profile, with potential benefit of improved long-term cosmesis.


Asunto(s)
Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Humanos , Técnicas de Planificación , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Estudios Retrospectivos
5.
J Med Radiat Sci ; 68(4): 364-370, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34310846

RESUMEN

INTRODUCTION: This study aimed to develop a single-isocentre volumetric modulated arc therapy (si-VMAT) technique for multiple brain metastases using knowledge-based planning software, comparing it with a multiple-isocentre stereotactic radiosurgery (mi-SRS) planning approach. METHODS: Twenty-six si-VMAT plans were created and uploaded into RapidPlanTM (RP) to create a si-VMAT model. Ten patients, with 2 to 6 metastases (mets), were planned with a si-VMAT technique utilising RP, and a mi-SRS technique on Brainlab iPlan. Paddick Conformity Index (PCI) was used to compare conformity. The volumes of the brain receiving 15Gy, 12Gy, 10Gy, 7.5Gy and 3Gy were also compared. Retrospective treatment times from the last eight patients treated were averaged for pre-imaging and beam on time to calculate treatment times for both techniques. RESULTS: There was a significant difference in the PCI scores for the mi-SRS plans (M = 0.667, SD = 0.114) and si-VMAT plans (M = 0.728, SD = 0.088), with PCI values suggesting better prescription dose conformity with the si-VMAT technique (P = 0.014). Percentage of total brain volume receiving low-dose wash at four of the five different dose levels was significantly less (P < 0.05) with mi-SRS. Average time to treat a single met with current mi-SRS technique is 25.7 min, with each additional met requiring this same amount of time. The average time to treat 2-3 mets using si-VMAT would be 25.3 min and 4+ metastases 33.5 min. CONCLUSION: A knowledge-based si-VMAT approach was efficient in planning and treating multi metastases while achieving clinically acceptable dosimetry with respect to dose conformity and low-dose fall off.


Asunto(s)
Neoplasias Encefálicas , Radiocirugia , Radioterapia de Intensidad Modulada , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Humanos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Estudios Retrospectivos
6.
Pract Radiat Oncol ; 11(2): e146-e153, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33186781

RESUMEN

PURPOSE: This study aimed to investigate the feasibility of using diagnostic computed tomography (dCT) for palliative radiation planning, removing the need for a planning computed tomography (pCT) scan. METHODS AND MATERIALS: A sequential 2-stage study was performed. Stage 1 was a retrospective analysis of 150 patients' dCTs and pCTs to review potential barriers to radiation planning, as well as assess the field of view (FOV), patient positioning, couch curvature, and Hounsfield unit (HU) variation, and its dosimetric impact. Stage 2 was a clinical implementation of dCT planning into the clinical care path. Eligible patients were simulated per the standard department protocol in the dCT position. Treatment was planned on the dCT and replicated on the pCT as a backup and comparator. The dCT plan was delivered with cone beam computed tomography (CT) image guidance. After treatment, the delivered plan was recalculated on the modified dCT to compare planned with delivered planning target volume (PTV) dose. RESULTS: Positron emission tomography-CT imaging was the most suited for diagnostic treatment planning. Metastases in the pelvis, abdomen, thoracic, and lumbar spines were the most reproducible. A curved, full-body vac-bag was designed to enable better replication of the posterior body curvature of dCT for treatment. There was minimal variation in mean HU from dCT to pCT scans. Dose difference due to HU variation in the thorax region due to the low-density tissue had the greatest variation. All patients in stage 2 (n = 30) were successfully treated using the dCT plan. Dosimetric evaluations were conducted comparing dCT and modified dCT plans, with the 95% dose coverage change in PTV between -2% to +2.5%. CONCLUSIONS: For palliative patients with bony and soft-tissue metastases, clinically acceptable plans can be produced using dCT. Diagnostic position can be replicated at treatment, eliminating the need for pCT with implications for streamlining and improving care for patients who require palliative radiation therapy.


Asunto(s)
Planificación de la Radioterapia Asistida por Computador , Tomografía Computarizada por Rayos X , Humanos , Dosificación Radioterapéutica , Estudios Retrospectivos
7.
J Med Radiat Sci ; 67(4): 310-317, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32881407

RESUMEN

INTRODUCTION: RapidPlan (RP), a knowledge-based planning system, aims to consistently improve plan quality and efficiency in radiotherapy. During the early stages of implementation, some of the challenges include knowing how to optimally train a model and how to integrate RP into a department. We discuss our experience with the implementation of RP into our institution. METHODS: We reviewed all patients planned using RP over a 7-month period following inception in our department. Our primary outcome was clinically acceptable plans (used for treatment) with secondary outcomes including model performance and a comparison of efficiency and plan quality between RP and manual planning (MP). RESULTS: Between November 2017 and May 2018, 496 patients were simulated, of which 217 (43.8%) had an available model. RP successfully created a clinically acceptable plan in 87.2% of eligible patients. The individual success of the 24 models ranged from 50% to 100%, with more than 90% success in 15 (62.5%) of the models. In 40% of plans, success was achieved on the 1st optimisation. The overall planning time with RP was reduced by up to 95% compared with MP times. The quality of the RP plans was at least equivalent to historical MP plans in terms of target coverage and organ at risk constraints. CONCLUSION: While initially time-consuming and resource-intensive to implement, plans optimised with RP demonstrate clinically acceptable plan quality, while significantly improving the efficiency of a department, suggesting RP and its application is a highly effective tool in clinical practice.


Asunto(s)
Planificación de la Radioterapia Asistida por Computador/métodos , Humanos , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada
8.
J Med Radiat Sci ; 67(3): 217-224, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32450610

RESUMEN

INTRODUCTION: To create and clinically validate knowledge-based planning (KBP) models for gynaecologic (GYN) and rectal cancer patients. Assessment of ecologic generalisability and predictive validity of conventional planning versus single calculation KBP was reviewed against practical metrics of planning time (PT) and radiation oncologist plan preference. METHOD: Study cohorts were 34 and 42 consecutively treated GYN and rectal cancer patients dosimetrically archived within the centre's research databank. For model training, structures and dose distributions from 22 and 32 GYN and rectal volumetric-modulated arc therapy (VMAT) plans were used in RapidPlan™. Prescription doses ranged from 45 to 60Gy in 25 fractions using a simultaneous integrated boost to 2-4 targets and up to 9 organ-at-risk volumes. For model validation, 12 GYN and 10 rectal were independent of the archive and a single pass KBP VMAT plan was created. Each plan was evaluated against the archived treated plan under blinded conditions for radiation oncologist preference using standard dosimetric quality parameters. RESULTS: All 22 plans generated in the KBP validation cohort met pre-set GYN and rectal cancer dosimetric quality metrics. Fifty per cent of GYN plans and eighty per cent of rectal plans were judged superior to the manually optimised plans. KBP reduced PT considerably for both tumour sites. CONCLUSION: Single pass KBP for GYN and rectal cancer patients produced clinically acceptable treatment plans which were non-inferior to conventionally optimised plans in 14 of 22 cases. Efficiencies captured by KBP will have predictable impacts on institutional workflows and resource allocation to facilitate adaptive planning.


Asunto(s)
Neoplasias de los Genitales Femeninos/radioterapia , Bases del Conocimiento , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias del Recto/radioterapia , Fraccionamiento de la Dosis de Radiación , Femenino , Humanos , Radioterapia de Intensidad Modulada , Reproducibilidad de los Resultados , Factores de Tiempo
9.
J Med Radiat Sci ; 67(1): 80-86, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32043819

RESUMEN

INTRODUCTION: Differences in knowledge and experience, patient anatomy and tumour location and manipulation of inverse planning objectives and priorities will lead to a variability in the quality of radiation planning. The aim of this study was to investigate whether parotid glands should be treated as separate or combined structures when using knowledge-based planning (KBP) to create oropharyngeal plans, based on the dose they receive. METHOD: Two separate RapidPlan (RP) models were created using the same 70 radical oropharyngeal patients. The 'separated model' divided the parotids into ipsilateral and contralateral structures. The 'combined model' did not separate the parotids. The models were independently validated using 20 patients not included in the models. The same dose constraints and priorities were applied to planning target volumes (PTVs) and organs at risk (OARs) for all plans. An auto-generated line objective and priority was applied in both models, with parotid mean dose and V50 doses evaluated and compared. RESULTS: Plans optimised using the combined model resulted in lower ipsilateral mean doses and lower V50 doses in 80% and 75% of cases, respectively. Fifty-five per cent of plans produced lower mean doses for the contralateral parotid when optimised using the combined model, while lower V50 doses were evenly split between the models. CONCLUSION: Combining the data for both parotids into one RP model resulted in better ipsilateral parotid sparing. Results also suggest that a combined parotid model will spare dose to the contralateral parotid; however, further investigation is required to confirm these results.


Asunto(s)
Neoplasias Orofaríngeas/diagnóstico por imagen , Orofaringe/diagnóstico por imagen , Glándula Parótida/diagnóstico por imagen , Modelación Específica para el Paciente , Planificación de la Radioterapia Asistida por Computador/métodos , Humanos , Órganos en Riesgo , Neoplasias Orofaríngeas/radioterapia , Dosificación Radioterapéutica
10.
Adv Radiat Oncol ; 4(4): 623-630, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31673655

RESUMEN

PURPOSE: To demonstrate feasibility and toxicity of linear accelerator-based stereotactic radiation therapy boost (SBRT) for prostate cancer, mimicking a high-dose-rate brachytherapy boost. METHODS AND MATERIALS: A phase 1 sequential dose escalation study of SBRT compared 20 Gy, 22 Gy, and 24 Gy to the prostate and 25 Gy, 27.5 Gy, and 30 Gy to the gross tumor volume in 2 fractions, combined with 46 Gy in 23 fractions of external beam radiation. Feasibility of dose escalation (volume receiving 125% and 150% of the dose) while meeting organ-at-risk dose constraints, grade 2 acute and late gastrointestinal and genitourinary toxicity, and freedom from biochemical failure were secondary endpoints. RESULTS: Thirty-six men with intermediate- and high-risk prostate cancer were enrolled with a median follow-up of 24 months. Sixty-four percent of patients had high-risk features. Nine men were enrolled to dose level 1, 6 to level 2, and 6 to level 3. Another 15 patients were treated at dose level 3 on the continuation study. Dose level 3 achieved superior 125% (23.75 Gy) and 150% (28.5 Gy) dose compared to dose levels 1 and 2, with minimal differences in organ-at-risk doses. Kaplan-Meier estimate of freedom from biochemical failure at 3 years was 93.3%. There were no late grade 2 or 3 gastrointestinal events. The late grade 2 genitourinary toxicity at 2 years was 19.3%. Prostate-specific membrane antigen positron emission tomography was performed at 2 years with no local recurrences. CONCLUSIONS: We have shown that a linear accelerator-based SBRT boost for prostate cancer is feasible and can achieve doses comparable to high-dose-rate boost up to the 150% isodose volumes. Rectal, bladder, and urethral doses remained low, and long-term toxicity was the same as or better than previous reports from high-dose-rate or low-dose-rate boost protocols.

11.
Med Dosim ; 41(1): 1-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26553473

RESUMEN

Target volume matching using cone-beam computed tomography (CBCT) is the preferred treatment verification method for lung cancer in many centers. However, radiation therapists (RTs) are trained in bony matching and not soft tissue matching. The purpose of this study was to determine whether RTs were equivalent to radiation oncologists (ROs) and radiologists (RDs) in alignment of the treatment CBCT with the gross tumor volume (GTV) defined at planning and in delineating the GTV on the treatment CBCT, as may be necessary for adaptive radiotherapy. In this study, 10 RTs, 1 RO, and 1 RD performed a manual tumor alignment and correction of the planning GTV to a treatment CBCT to generate an isocenter correction distance for 15 patient data sets. Participants also contoured the GTV on the same data sets. The isocenter correction distance and the contoured GTVs from the RTs were compared with the RD and RO. The mean difference in isocenter correction distances was 0.40cm between the RO and RD, 0.51cm between the RTs, and RO and 0.42cm between the RTs and RD. The 95% CIs were smaller than the equivalence limit of 0.5cm, indicating that the RTs were equivalent to the RO and RD. For GTV delineation comparisons, the RTs were not found to be equivalent to the RD or RO. The alignment of the planning defined GTV and treatment CBCT using soft tissue matching by the RTs has been shown to be equivalent to those by the RO and RD. However, tumor delineation by the RTs on the treatment CBCT was not equivalent to that of the RO and RD. Thus, it may be appropriate for RTs to undertake soft tissue alignment based on CBCT; however, further investigation may be necessary before RTs undertake delineation for adaptive radiotherapy purposes.


Asunto(s)
Competencia Clínica/estadística & datos numéricos , Tomografía Computarizada de Haz Cónico , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Radioterapia Guiada por Imagen/normas , Humanos , Radioterapia Guiada por Imagen/estadística & datos numéricos
12.
J Med Radiat Sci ; 62(3): 177-83, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26451239

RESUMEN

INTRODUCTION: The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. METHODS: A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 days post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). RESULTS: There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm(3) (4-118) and CT2ch: median 16 cm(3), (2-99), (P = 0.01), but no significant volume reduction thereafter. CONCLUSION: Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence.

13.
Med Dosim ; 39(2): 163-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24393498

RESUMEN

Radiation therapy to the breast is a complex task, with many different techniques that can be employed to ensure adequate dose target coverage while minimizing doses to the organs at risk. This study compares the dose planning outcomes of 3 radiation treatment modalities, 3 dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and static tomotherapy, for left-sided whole-breast radiation treatment with a simultaneous integrated boost (SIB). Overall, 20 patients with left-sided breast cancer were separated into 2 cohorts, small and large, based on breast volume. Dose plans were produced for each patient using 3D-CRT, IMRT, and static tomotherapy. All patients were prescribed a dose of 45Gy in 20 fractions to the breast with an SIB of 56Gy in 20 fractions to the tumor bed and normalized so that D98% > 95% of the prescription dose. Dosimetric comparisons were made between the 3 modalities and the interaction of patient size. All 3 modalities offered adequate planning target volume (PTV) coverage with D98% > 95% and D2% < 107%. Static tomotherapy offered significantly improved (p = 0.006) dose homogeneity to the PTVboost eval (0.079 ± 0.011) and breast minus the SIB volume (BreastSIB) (p < 0.001, 0.15 ± 0.03) compared with the PTVboost eval (0.085 ± 0.008, 0.088 ± 0.12) and BreastSIB (0.22 ± 0.05, 0.23 ± 0.03) for IMRT and 3D-CRT, respectively. Static tomotherapy also offered statistically significant reductions (p < 0.001) in doses to the ipsilateral lung mean dose of 6.79 ± 2.11Gy compared with 7.75 ± 2.54Gy and 8.29 ± 2.76Gy for IMRT and 3D-CRT, respectively, and significantly (p < 0.001) reduced heart doses (mean = 2.83 ± 1.26Gy) compared to both IMRT and 3D-CRT (mean = 3.70 ± 1.44Gy and 3.91 ± 1.58Gy). Static tomotherapy is the dosimetrically superior modality for the whole breast with an SIB compared with IMRT and 3D-CRT. IMRT is superior to 3D-CRT in both PTV dose conformity and reduction of mean doses to the ipsilateral lung.


Asunto(s)
Neoplasias de la Mama/radioterapia , Radioterapia de Intensidad Modulada/métodos , Femenino , Humanos , Dosis de Radiación , Planificación de la Radioterapia Asistida por Computador
14.
J Med Imaging Radiat Oncol ; 56(5): 499-509, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23043567

RESUMEN

Inter- and intra-fraction motion during radiation therapy for breast cancer has been a widely researched topic. Recently, however, with the emergence of new technologies and techniques such as intensity modulated radiation therapy (IMRT), field in field, volumetric modulated arc therapy (VMAT), tomotherapy and partial breast irradiation (PBI), the magnitude of this movement has become more important. The aim of this study is to provide a comprehensive summary of the literature relating to the magnitude of motion during radiation therapy for a breast cancer patient. A systematic review of the literature was conducted using Medline, Cinhal, Embase, Scopus and Web of Science. Studies included were limited to women having radical radiation therapy to the whole breast in the supine position. Studies needed to report quantitatively on the magnitude of inter- and intra-fraction motion using electronic portal imaging, port films or kilovoltage imaging techniques. Eighteen articles fitted the selection criteria. The averages of random and systematic error for inter- and intra-fraction movement were reported using central lung distance, central irradiated width, central beam edge to skin distance and cranio-caudal distance measurements, or isocentric matching techniques. Inter-fraction motion was consistently larger than intra-fraction motion but, on average, within a 5 mm tolerance. There were, though, large maximum inter- and intra-fraction variations observed in the measurements of individual patients, which indicate the need for daily inter- and intra- fraction motion management before implementing IMRT, VMAT, tomotherapy or PBI techniques.


Asunto(s)
Artefactos , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/radioterapia , Fraccionamiento de la Dosis de Radiación , Posicionamiento del Paciente/métodos , Radioterapia Conformacional/métodos , Radioterapia Guiada por Imagen/métodos , Femenino , Humanos , Movimiento (Física) , Radiografía , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Posición Supina
15.
Radiother Oncol ; 90(2): 247-52, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19135275

RESUMEN

BACKGROUND: To reduce the waiting time between diagnosis and the start of radiation therapy, some departments have introduced appointments outside of conventional working hours, but the inconvenience this may cause to patients is unknown. We examined, from the patient's perspective, whether reduced waiting times to treatment would be sufficient to trade off against potentially inconvenient appointment times. METHOD: We interviewed patients receiving radiation therapy at a major teaching hospital between January and May 2005. Two patient groups were considered: those treated during conventional working hours (8.30 am to 4.30 pm), and those treated outside these hours. Patients were asked to trade a reduction in waiting time to the start of treatment against treatment outside conventional working hours. RESULTS: Of 129 patients interviewed, 77 were treated during conventional working hours and 52 outside these hours. Fifty-seven (44%) were male and 52 (40%) were aged over 60 years. To prefer treatment out of working hours, patients being treated during conventional working hours required a larger reduction in waiting time (odds ratio 2.36, 95% CI 0.97-5.76). Patients with curable disease and those who had made few changes in their lifestyle throughout the treatment were more likely to accept treatment outside of conventional working hours. CONCLUSION: It is impractical to satisfy the treatment-time preferences of all patients. However, many patients prefer treatment outside of normal treatment times if this would reduce the time until the start of radiation therapy. Evaluating the effect of waiting times on patients' perceptions of their disease control provides important information in allocating treatment hours and appointment times.


Asunto(s)
Atención Posterior , Citas y Horarios , Satisfacción del Paciente , Servicio de Radiología en Hospital/organización & administración , Radioterapia , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Gales del Sur , Factores Socioeconómicos , Listas de Espera , Adulto Joven
16.
Radiother Oncol ; 89(3): 361-7, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18524400

RESUMEN

BACKGROUND AND PURPOSE: To determine whether radiation therapists (RTTs) and radiation oncologists (ROs) believe RTTs can lead patient treatment reviews. MATERIALS AND METHODS: Phase 1 involved the construction of a checklist of the procedures followed during RO treatment reviews. Phase 2 employed the checklist to monitor the frequency of review procedures. From these data, questionnaires regarding RTTs' ability to carry out these procedures to be used in Phase 3 were developed. The questionnaires were distributed to RTTs and ROs at two large public cancer centres. RESULTS: The majority of RTTs and ROs believed that RTTs could provide assurance and answer questions about side effects, treatment techniques, cancer, nutrition and logistics. ROs and RTTs agreed that RTTs were not capable of recommending medication or answering medical questions. Most RTTs thought they could decide if a patient should take a break from treatment if a standard protocol existed, but the ROs disagreed (P < 0.01). ROs believed that RTTs were capable of using the Common Toxicity Criteria system to grade side effects, but RTTs disagreed (P < 0.01). Concerns were raised about training, legalities, workloads, logistics, cost, patients' perspectives and remuneration. CONCLUSION: RTTs and ROs believed RTTs could lead treatment reviews with training, and support this role development.


Asunto(s)
Oncología por Radiación , Radioterapia , Actitud del Personal de Salud , Humanos , Radioterapia/normas , Encuestas y Cuestionarios
17.
Med Teach ; 23(2): 198-204, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11371299

RESUMEN

Five hundred and three experienced practitioners involved in management from four professional fields (medical radiation science, occupational therapy, speech pathology and physiotherapy) representing a range of health care settings participated in a survey. The survey examined the importance attached to managerial competencies for the beginning practitioner. The most important grouping related to management of future planning. Underlying competencies included decision making regarding time management and communication with other staff. The second most important grouping of managerial competencies related to organisational practices. These competencies included strategic and organisation-wide management processes associated with change, vision, organisational awareness and decision making. The third grouping of managerial competencies related to knowledge regarding legislation and in particular compliance with occupational health and safety regulations. Other competencies were seen as less important for the beginning practitioner. The implications of these findings are discussed in relation to health science curriculum development in higher education.

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