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1.
Br J Radiol ; 96(1144): 20220771, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36809197

RESUMO

OBJECTIVE: The aim of this study was to evaluate clinical results and prognostic factors in a cohort of patient with oligometastatic esophagogastric adenocarcinoma treated with stereotactic radiation therapy (SRT). METHODS: This retrospective study included patients affected by 1-3 metastases treated with SRT from 2013 to 2021. Local control (LC), overall survival (OS), progression-free survival (PFS), time to polymetastatic dissemination (TTPD) and time to systemic therapy change/initiation (TTS) were evaluated. RESULTS: Between 2013 and 2021, 55 patients were treated with SRT on 80 oligometastatic sites. Median follow-up was 20 months. Nine patients had local progression. 1 and 3 years LC was respectively 92 and 78%. 41 patients experienced further distant disease progression, median PFS was 9.6 months, 1 and 3 years PFS was respectively 40 and 15%. 34 patients died, median OS was 26.6 months, 1 and 3 years OS was respectively 78 and 40%. During follow-up, 24 patients changed or initiated a new systemic therapy; median TTS time was 9 months. 27 patients experienced poliprogression, 44% after 1 year and 52% after 3 years. Median TTPD was 8 months. The best local response (LR), tyming of metastases and PS were related with prolonged PFS on multivariate analysis. LR was correlated with OS at multivariate analysis. CONCLUSION: SRT represents a valid treatment for oligometastatic esophagogastric adenocarcinoma. CR correlated with PFS and OS, while metachronous metastasis and a good PS correlated with a better PFS. ADVANCES IN KNOWLEDGE: In selected gastroesopagheal oligometastatic patients, SRT can prolong OS Local response to SRT, metachronous timing of metastases and better PS improve PFS.Local response correlates with OS.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , Radiocirurgia , Humanos , Radiocirurgia/métodos , Prognóstico , Neoplasias Pulmonares/patologia , Estudos Retrospectivos , Adenocarcinoma/radioterapia , Resultado do Tratamento
2.
Radiat Oncol ; 17(1): 200, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36474297

RESUMO

BACKGROUND: To analyze RapidPlan knowledge-based models for DVH estimation of organs at risk from breast cancer VMAT plans presenting arc sectors en-face to the breast with zero dose rate, feature imposed during the optimization phase (avoidance sectors AS). METHODS: CT datasets of twenty left breast patients in deep-inspiration breath-hold were selected. Two VMAT plans, PartArc and AvoidArc, were manually generated with double arcs from ~ 300 to ~ 160°, with the second having an AS en-face to the breast to avoid contralateral breast and lung direct irradiation. Two RapidPlan models were generated from the two plan sets. The two models were evaluated in a closed loop to assess the model performance on plans where the AS were selected or not in the optimization. RESULTS: The PartArc plans model estimated DVHs comparable with the original plans. The AvoidArc plans model estimated a DVH pattern with two steps for the contralateral structures when the plan does not contain the AS selected in the optimization phase. This feature produced mean doses of the contralateral breast, averaged over all patients, of 0.4 ± 0.1 Gy, 0.6 ± 0.2 Gy, and 1.1 ± 0.2 Gy for the AvoidArc plan, AvoidArc model estimation, RapidPlan generated plan, respectively. The same figures for the contralateral lung were 0.3 ± 0.1 Gy, 1.6 ± 0.6 Gy, and 1.2 ± 0.5 Gy. The reason was found in the possible incorrect information extracted from the model training plans due to the lack of knowledge about the AS. Conversely, in the case of plans with AS set in the optimization generated with the same AvoidArc model, the estimated and resulting DVHs were comparable. Whenever the AvoidArc model was used to generate DVH estimation for a plan with AS, while the optimization was made on the plan without the AS, the optimizer evidentiated the limitation of a minimum dose rate of 0.2 MU/°, resulting in an increased dose to the contralateral structures respect to the estimation. CONCLUSIONS: The RapidPlan models for breast planning with VMAT can properly estimate organ at risk DVH. Attention has to be paid to the plan selection and usage for model training in the presence of avoidance sectors.

3.
Radiol Med ; 127(12): 1407-1411, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36201098

RESUMO

Recent advances in non-metastatic breast cancer radiation therapy significantly reshaped our views on modern dose and fractionation schedules. Especially the advent of hypofractionation and partial breast irradiation defined a new concept of treatment optimization, that should strongly include both patient and tumour characteristics in the physician's decision-making process. Unfortunately, hypofractionation for breast cancer radiation therapy needed long time to enter the routine practice during the last decades despite the level-1 evidence published over time. Hereby we present the Italian Association for Radiotherapy and Clinical Oncology (AIRO) Breast Cancer Group position statements for postoperative breast cancer radiation therapy volume, dose, and fractionation to harmonically boost routine clinical practice implementation following evidence-based data.


Assuntos
Neoplasias da Mama , Radioterapia (Especialidade) , Feminino , Humanos , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Fracionamento da Dose de Radiação , Oncologia , Radioterapia Adjuvante , Itália
4.
Curr Oncol ; 29(10): 7858-7867, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36290898

RESUMO

AIMS: We report the mature toxicity data of a phase II non-randomized trial on the use of SBRT for lung and liver oligometastases. METHODS: Oligometastatic patients from breast cancer were treated with SBRT for up to five lung and/or liver lesions. Inclusion criteria were: age > 18 years, ECOG 0-2, diagnosis of breast cancer, less than five lung/liver lesions (with a maximum diameter <5 cm), metastatic disease confined to the lungs and liver or extrapulmonary or extrahepatic disease stable or responding to systemic therapy. Various dose-fractionation schedules were used. Then, a 4D-CT scan and FDG-CTPET were acquired for simulation and fused for target definition. RESULTS: From 2015 to 2021, 64 patients and a total of 90 lesions were irradiated. Treatment was well tolerated, with no G 3-4 toxicities. No grade ≥3 toxicities were registered and the coprimary endpoint of the study was met. Median follow-up was 19.4 months (range 2.6-73.1). CONCLUSIONS: The co-primary endpoint of this phase II trial was met, showing excellent tolerability of SBRT for lung and liver oligometastatic in breast cancer patients. Until efficacy data will mature with longer follow-up, SBRT should be regarded as an opportunity for oligometastatic breast cancer patients.


Assuntos
Neoplasias da Mama , Neoplasias Hepáticas , Radiocirurgia , Humanos , Adulto , Pessoa de Meia-Idade , Feminino , Radiocirurgia/efeitos adversos , Neoplasias da Mama/radioterapia , Neoplasias da Mama/patologia , Estudos Prospectivos , Fluordesoxiglucose F18 , Pulmão/patologia , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/secundário
5.
Eur J Breast Health ; 18(4): 315-322, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36248756

RESUMO

Objective: Patients with triple-negative (TN) or human epidermal growth factor 2 (HER2)-enriched ipsilateral breast cancer recurrence (IBCR) seem to be excluded from a second breast-conserving surgery (BCS) under the assumption that salvage mastectomy would provide better oncological outcomes. The objective of this study was to describe the clinical features of these patients, to compare the two surgical alternatives (salvage mastectomy versus second BCS) in terms of oncological results, and to identify independent factors influencing prognosis and surgical treatment. Materials and Methods: We retrospectively reviewed all the consecutive patients with histologically confirmed TN or HER2-enriched IBCR. Disease-free survival (DFS), distant disease-free survival (DDFS), overall survival (OS), and breast cancer-specific survival (BCSS) were analyzed and compared between the two groups. Results: Eighty-five patients were affected by TN or HER2-enriched IBCR. The majority of patients (72.9%) were treated with salvage mastectomy. There was no significant difference in terms of DFS between patients receiving a second BCS or mastectomy (p = 0.596). However, patients undergoing a second BCS had significantly better DDFS, OS and BCSS compared to mastectomy (p = 0.009; p = 0.002; p = 0.001, respectively). Tumor dimension <16 mm was found to significantly increase the probability of receiving a second BCS and positively affects recurrence and survival outcomes. Salvage mastectomy represents an independent poor prognostic factor for OS and BCSS. Conclusion: Salvage mastectomy is not always necessary and it does not seem to increase survival compared to a second BCS. In patients with small aggressive subtypes of IBCR, a second conservative approach can still be evaluated and offered, presenting acceptable loco-regional control and survival.

6.
Radiat Oncol ; 17(1): 150, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36028862

RESUMO

BACKGROUND: To investigate the performance of a narrow-scope knowledge-based RapidPlan (RP) model for optimisation of intensity-modulated proton therapy (IMPT) and volumetric modulated arc therapy (VMAT) plans applied to patients with pleural mesothelioma. Second, estimate the potential benefit of IMPT versus VMAT for this class of patients. METHODS: A cohort of 82 patients was retrospectively selected; 60 were used to "train" a dose-volume histogram predictive model; the remaining 22 provided independent validation. The performance of the RP models was benchmarked, comparing predicted versus achieved mean and near-to-maximum dose for all organs at risk (OARs) in the training set and by quantitative assessment of some dose-volume metrics in the comparison of the validation RP-based data versus the manually optimised training datasets. Treatment plans were designed for a prescription dose of 44 Gy in 22 fractions (proton doses account for a fixed relative biological effectiveness RBE = 1.1). RESULTS: Training and validation RP-based plans resulted dosimetrically similar for both VMAT and IMPT groups, and the clinical planning aims were met for all structures. The IMPT plans outperformed the VMAT ones for all OARs for the contra-lateral and the mean and low dose regions for the ipsilateral OARs. Concerning the prediction performance of the RP models, the linear regression for the near-to-maximum dose resulted in Dachieved = 1.03Dpredicted + 0.58 and Dachieved = 1.02Dpredicted + 1.46 for VMAT and IMPT, respectively. For the mean dose it resulted: Dachieved = 0.99Dpredicted + 0.34 and Dachieved = 1.05Dpredicted + 0.27 respectively. In both cases, the linear correlation between prediction and achievement is granted with an angular coefficient deviating from unity for less than 5%. Concerning the dosimetric comparison between manual plans in the training cohort and RP-based plans in the validation cohort, no clinical differences were observed for the target volumes in both the VMAT and IMPT groups. Similar consistency was observed for the dose-volume metrics analysed for the OAR. This proves the possibility of achieving the same quality of plans with manual procedures (the training set) or with automated RP-based methods (the validation set). CONCLUSION: Two models were trained and validated for VMAT and IMPT plans for pleural mesothelioma. The RP model performance resulted satisfactory as measured by the agreement between predicted and achieved (after full optimisation) dose-volume metrics. The IMPT plans outperformed the VMAT plans for all the OARs (with different intensities for contra- or ipsilateral structures). RP-based planning enabled the automation of part of the optimisation and the harmonisation of the dose-volume results between training and validation. The IMPT data showed a systematic significant dosimetric advantage over VMAT. In general, using an RP-based approach can simplify the optimisation workflow in these complex treatment indications without impacting the quality of plans.


Assuntos
Mesotelioma , Terapia com Prótons , Radioterapia de Intensidade Modulada , Humanos , Órgãos em Risco , Prótons , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos
7.
Curr Oncol ; 29(7): 4893-4901, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35877248

RESUMO

BACKGROUND: This study evaluated the outcome, toxicity and predictive factors in patients unfit for concurrent chemo-radiotherapy (CT-RT) treated with hypofractionated sequential CT-RT or exclusive radiotherapy (RT) for locally advanced non-small cell lung cancer (LA-NSCLC). METHODS: We included patients affected by LA-NSCLC (stage IIA-IVA) treated with a total dose of 50-60 Gy in 20 fractions. The primary outcomes were local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS) and overall survival (OS). Univariate analysis was used to correlate outcomes with prognostic factors. RESULTS: Between 2011 and 2019, 210 patients were treated, 113 (53.8%) with sequential CT-RT and 97 (46.2%) with exclusive RT. After a median follow-up of 15.3 months, 74 patients (35.2%) had a local progression and 133 (63.3%) had a distant progression. The one-, two- and five-year LC were 73.6%, 55.3% and 47.9%, respectively. At the time of analysis, 167 patients (79.5%) died. The one-, two- and five-year OS were 64.7%, 36% and 20%, respectively. PTV volume correlated with PFS (p = 0.001) and LC (p = 0.005). Acute and late toxicity occurred in 82% and 26% of patients. CONCLUSIONS: Albeit with the known limitations of a retrospective and heterogeneous study, our work shows that hypofractionated sequential CT-RT or exclusive RT offer a good local control and toxicity profile and a promising survival rate in LA-NSCLC patients unfit for the concurrent CT-RT scheme.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Radioterapia de Intensidade Modulada , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Estudos Retrospectivos , Taxa de Sobrevida
8.
Ann Surg Oncol ; 29(9): 5732-5744, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35552930

RESUMO

BACKGROUND: The SINODAR-ONE trial is a prospective noninferiority multicenter randomized study aimed at assessing the role of axillary lymph node dissection (ALND) in patients undergoing either breast-conserving surgery or mastectomy for T1-2 breast cancer (BC) and presenting one or two macrometastatic sentinel lymph nodes (SLNs). The endpoints were to evaluate whether SLN biopsy (SLNB) only was associated with worsening of the prognosis compared with ALND in terms of overall survival (OS) and relapse. METHODS: Patients were randomly assigned (1:1 ratio) to either removal of ≥ 10 axillary level I/II non-SLNs followed by adjuvant therapy (standard arm) or no further axillary treatment (experimental arm). RESULTS: The trial started in April 2015 and ceased in April 2020, involving 889 patients. Median follow-up was 34.0 months. There were eight deaths (ALND, 4; SNLB only, 4), with 5-year cumulative mortality of 5.8% and 2.1% in the standard and experimental arm, respectively (p = 0.984). There were 26 recurrences (ALND 11; SNLB only, 15), with 5-year cumulative incidence of recurrence of 6.9% and 3.3% in the standard and experimental arm, respectively (p = 0.444). Only one axillary lymph node recurrence was observed in each arm. The 5-year OS rates were 98.9% and 98.8%, in the ALND and SNLB-only arm, respectively (p = 0.936). CONCLUSIONS: The 3-year survival and relapse rates of T1-2 BC patients with one or two macrometastatic SLNs treated with SLNB only, and adjuvant therapy, were not inferior to those of patients treated with ALND. These results do not support the use of routine ALND.


Assuntos
Neoplasias da Mama , Linfonodo Sentinela , Axila/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Excisão de Linfonodo/métodos , Linfonodos/patologia , Linfonodos/cirurgia , Metástase Linfática/patologia , Mastectomia , Recidiva Local de Neoplasia/patologia , Estudos Prospectivos , Linfonodo Sentinela/patologia , Linfonodo Sentinela/cirurgia , Biópsia de Linfonodo Sentinela
9.
J Contemp Brachytherapy ; 12(3): 207-215, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32695191

RESUMO

PURPOSE: To evaluate clinical results of catheter-based interstitial high-dose-rate (HDR) brachytherapy (BT) as adjuvant treatment in previously irradiated recurrent breast cancer. MATERIAL AND METHODS: Between January 2011 and September 2015, 31 consecutive patients with histologically confirmed recurrent breast cancer after conservative surgery and conventional whole breast radiotherapy, were retreated with a second conservative surgical resection and reirradiated with adjuvant interstitial HDR-BT. None of the brachytherapy implant was performed during the quadrantectomy procedure. A dose of 34 Gy in 10 fractions, 2 fractions per day, with a minimal interval of 6 hours was delivered. RESULTS: At the time of the implant, the median age of patients was 59.7 years (range, 39.3-74.9 years). The median time from first treatment until BT for local recurrence was 11.9 years (range, 2.5-27.8 years). The median interval between salvage surgery and BT was 3.6 months (range, 1-8.2 months). No acute epidermitis or soft tissue side effects higher than grade 2 were recorded, with good cosmetic results in all patients. Most of the patients presented grade 1-2 late side effects. Only one patient developed grade 3 liponecrosis. After a median follow-up of 73.7 months (range, 28.8-102.4 months), the overall survival and cancer specific survival were 87.1% and 90.3%, respectively; 5-year local control and 5-year progression-free survival rate were 90.3% and 83.9%, respectively. CONCLUSIONS: Our preliminary analysis showed that HDR-BT is a feasible treatment for partial breast reirradiation offering very low complications rate and fast procedure. Higher patients' cohort is warranted in order to define the role of this treatment modality in the breast conservative management of local recurrence.

10.
J Cancer Res Clin Oncol ; 145(7): 1887-1896, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31144158

RESUMO

PURPOSE: To report the dosimetric feasibility of the radiation technique HALFMOON (Helical ALtered Fractionation for iMplant partial OmissiON) for post-mastectomy radiation therapy (PMRT) in intermediate-high-risk breast cancer patients with implant-based immediate breast reconstruction, where the clinical target volume (CTV) does not include the whole implant (implant-sparing approach). METHODS: In the HALFMOON technique, the CTV consisted of skin, subcutaneous tissues, and pectoralis major muscle, excluding the implant, chest wall muscles, and rib plane. The HALFMOON plans were compared with conventionally contoured CTV plans, in which the whole implant, chest wall muscles, and ribs plane were included in the CTV, in a ratio 1:3. All patients underwent hypofractionated treatment of 40.05 Gy/15 fractions, using helical Tomotherapy®. RESULTS: Eighteen patients undergoing HALFMOON technique were compared to 54 subjects treated with conventionally contoured CTV plans. No difference was found in the planning target volume coverage between the two groups. Conversely, a statistically relevant dose reduction in HALFMOON patients was observed for ipsilateral lung (D15%, p < 0.0001; D20%, p < 0.0001; D35%, p = 0.003), contralateral lung (D20%, p = 0.048), contralateral breast (D15%, p = 0.031; D20%, p = 0.047), and stomach (Dmean, p = 0.011). Regarding the implant, V90% and D50% decreased by 46% and 8%, respectively, in the HALFMOON plans (p < 0.0001). CONCLUSION: The HALFMOON approach is technically feasible and resulted in high-dose conformity of the target with a significant reduction of radiation dose delivered to implant and other organs. A clinical study is needed to assess the impact on reconstruction cosmetic outcome and local control.


Assuntos
Implantes de Mama , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias da Mama/diagnóstico por imagem , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Mastectomia/métodos , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Hipofracionamento da Dose de Radiação , Radioterapia Adjuvante , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos
11.
J Contemp Brachytherapy ; 11(6): 516-526, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31969909

RESUMO

PURPOSE: To analyse the survival outcomes and toxicity profile of patients treated with pulsed-dose-rate (PDR) brachytherapy (BT) after intensity-modulated radiation therapy (IMRT) for uterine cervical cancer in a single institution. MATERIAL AND METHODS: Between March 2011 and December 2014, 50 patients with histologically proven stages IB1-IVB cervical cancer were treated with IMRT followed by PDR-BT boost. Radiation treatment consisted of IMRT to pelvic with or without paraaortic lymph nodes to a total dose of 45-50.4 Gy. Weekly concomitant chemotherapy was administered to 45 patients. PDR-BT boost was delivered with a median dose of 30 Gy to the high-risk clinical target volume (HR-CTV) after a median time of 14 days since IMRT. Acute and late toxicity were evaluated by Radiation Therapy Oncology Group (RTOG) - European Organization for Research and Treatment of Cancer (EORTC) scoring criteria and Subjective Objective Management Analytic-Late Effects of Normal Tissues (SOMA-LENT) criteria. RESULTS: Two patients had tumour persistence at 6 months after the end of BT. After a median follow-up of 33 months, 6 distant metastases with or without regional relapse were observed. The 1- and 5-year progression-free survival was 83% (95% CI: 69-91%) and 76% (95% CI: 61-86%), whereas the 3- and 5-year overall survival was 91% (95% CI: 78-97%) and 76% (95% CI: 56-88%), respectively. Urinary and rectal toxicity higher than grade 2 was observed in 6.3% and 17% of patients, respectively. Five patients (10.6%) had grade 4 gastrointestinal toxicity requiring colostomy. CONCLUSIONS: Our study confirms that the combination of IMRT and PDR-BT can be considered an effective treatment for cervical cancer, ensuring high local control, despite the high percentage of locally advanced disease.

12.
Med Oncol ; 35(5): 73, 2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29667046

RESUMO

As a result of aging, the number of patients with cardiac implantable electronic device (CIED) requiring radiotherapy (RT) continues to rise. The aim of this work was to evaluate RT-related malfunctions of CIED in a cohort of patients who underwent RT in our clinic from June 2010 to December 2016. We retrospectively analyzed 93 RT treatments in 63 patients with CIEDs. Patients were treated with 3D conformal RT, intensity-modulated RT and stereotactic RT. We collected clinical characteristics of cancer, models of CIEDs, total RT dose to tumor and radiation energy. Radiation dose delivered to CIED and its dysfunctions after RT was evaluated. Subgroup analysis of 48 RT treatments (32 patients) on chest and neck plus on 13 RT treatments (12 patients) with 18 MV neutron-producing photon energy considered as high risk was performed. The number of treatments of patients with CIEDs increased from 0.3% in 2011 to 1.2% in 2016. Two patients, treated with 18 MV photon beam, with implantable cardioverter-defibrillators (ICDs) that received a maximum dose of around 2.1 Gy, experienced adverse events: a reprogramming of ICD when the patient reached a delivered dose to the tumor of 32 Gy, and an altered sensing function requiring replacement after 11 months from the end of RT. Nearly 2% of patients with CIEDs from high-risk patients subgroup had experienced a damage of the device. Close cooperation between radiation oncologists, cardiologists, medical physicists and radiation technologists is needed to achieve the best practice management in these patients.


Assuntos
Desfibriladores Implantáveis , Neoplasias/radioterapia , Marca-Passo Artificial , Falha de Prótese/efeitos da radiação , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição à Radiação/efeitos adversos , Radiometria , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos
13.
Phys Med ; 39: 25-32, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28711185

RESUMO

BACKGROUND AND PURPOSE: 3D printing is rapidly evolving and further assessment of materials and technique is required for clinical applications. We evaluated 3D printed boluses with acrylonitrile butadiene styrene (ABS) and polylactide (PLA) at different infill percentage. MATERIAL AND METHODS: A low-cost 3D printer was used. The influence of the air inclusion within the 3D printed boluses was assessed thoroughly both with treatment planning system (TPS) and with physical measurements. For each bolus, two treatment plans were calculated with Monte Carlo algorithm, considering the computed tomography (CT) scan of the 3D printed bolus or modelling the 3D printed bolus as a virtual bolus structure with a homogeneous density. Depth dose measurements were performed with Gafchromic films. RESULTS: High infill percentage corresponds to high density and high homogeneity within bolus material. The approximation of the bolus in the TPS as a homogeneous material is satisfying for infill percentages greater than 20%. Measurements performed with PLA boluses are more comparable to the TPS calculated profiles. For boluses printed at 40% and 60% infill, the discrepancies between calculated and measured dose distribution are within 5%. CONCLUSIONS: 3D printing technology allows modulating the shift of the build-up region by tuning the infill percentage of the 3D printed bolus in order to improve superficial target coverage.


Assuntos
Impressão Tridimensional , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Humanos , Método de Monte Carlo , Fótons , Radiometria , Tomografia Computadorizada por Raios X
14.
Phys Med ; 32(12): 1698-1706, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27592531

RESUMO

PURPOSE: Dosimetric assessment of high dose rate (HDR) brachytherapy applicators, printed in 3D with acrylonitrile butadiene styrene (ABS) at different infill percentage. MATERIALS AND METHODS: A low-cost, desktop, 3D printer (Hamlet 3DX100, Hamlet, Dublin, IE) was used for manufacturing simple HDR applicators, reproducing typical geometries in brachytherapy: cylindrical (common in vaginal treatment) and flat configurations (generally used to treat superficial lesions). Printer accuracy was investigated through physical measurements. The dosimetric consequences of varying the applicator's density by tuning the printing infill percentage were analysed experimentally by measuring depth dose profiles and superficial dose distribution with Gafchromic EBT3 films (International Specialty Products, Wayne, NJ). Dose distributions were compared to those obtained with a commercial superficial applicator. RESULTS: Measured printing accuracy was within 0.5mm. Dose attenuation was not sensitive to the density of the material. Surface dose distribution comparison of the 3D printed flat applicators with respect to the commercial superficial applicator showed an overall passing rate greater than 94% for gamma analysis with 3% dose difference criteria, 3mm distance-to-agreement criteria and 10% dose threshold. CONCLUSION: Low-cost 3D printers are a promising solution for the customization of the HDR brachytherapy applicators. However, further assessment of 3D printing techniques and regulatory materials approval are required for clinical application.


Assuntos
Braquiterapia , Dosimetria Fotográfica/instrumentação , Impressão Tridimensional , Doses de Radiação , Absorção de Radiação , Dosagem Radioterapêutica
15.
Ecancermedicalscience ; 10: 657, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27563352

RESUMO

The aim of this study is to access the feasibility, toxicity profile, and tumour outcome of an organ preservation curative approach in non-metastatic muscle-invasive bladder cancer. A retrospective analysis was conducted on patients affected by M0 bladder cancer, who refused cystectomy and were treated with a curative approach. The standard bladder preservation scheme included maximal transurethral resection of bladder tumour (TURBT) and combination of radiotherapy and platin-based chemotherapy, followed by endoscopic evaluation, urine cytology, and instrumental evaluation. Thirteen patients fulfilled the inclusion criteria. TNM stage was cT2cN0M0 and cT2cNxM0, in 12 and one patients, respectively. All patients had transitional cell cancer. Twelve patients completed the whole therapeutic programme (a bimodal treatment without chemotherapy for one patient). Median follow-up is 36 months. None of the patients developed severe urinary or intestinal acute toxicity. In 10 patients with a follow-up > 6 months, no cases of severe late toxicity were observed. Response evaluated in 12 patients included complete response and stable disease in 11 patients (92%), and one patient (8%), respectively. At the time of data analysis (March 2016), 10 patients (77%) are alive with no evidence of disease, two patients (15%) died for other reasons, and one patient has suspicious persistent local disease. The trimodality approach, including maximal TURBT, radiotherapy, and chemotherapy for muscle-invasive bladder cancer, is well-tolerated and might be considered a valid and feasible option in fit patients who refuse radical cystectomy.

16.
Br J Radiol ; 89(1065): 20150981, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27384381

RESUMO

OBJECTIVE: Low-dose-rate brachytherapy (LDR-BT) in localized prostate cancer is available since 15 years in Italy. We realized the first national multicentre and multidisciplinary data collection to evaluate LDR-BT practice, given as monotherapy, and outcome in terms of biochemical failure. METHODS: Between May 1998 and December 2011, 2237 patients with early-stage prostate cancer from 11 Italian community and academic hospitals were treated with iodine-125 ((125)I) or palladium-103 LDR-BT as monotherapy and followed up for at least 2 years. (125)I seeds were implanted in 97.7% of the patients: the mean dose received by 90% of target volume was 145 Gy; the mean target volume receiving 100% of prescribed dose (V100) was 91.1%. Biochemical failure-free survival (BFFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method. Log-rank test and multivariable Cox regression were used to evaluate the relationship of covariates with outcomes. RESULTS: Median follow-up time was 65 months. 5- and 7-year DSS, OS and BFFS were 99 and 98%, 94 and 89%, and 92 and 88%, respectively. At multivariate analysis, the National Comprehensive Cancer Network score (p < 0.0001) and V100 (p = 0.09) were correlated with BFFS, with V100 effect significantly different between patients at low risk and those at intermediate/high risk (p = 0.04). Short follow-up and lack of toxicity data represent the main limitations for a global evaluation of LDR-BT. CONCLUSION: This first multicentre Italian report confirms LDR-BT as an excellent curative modality for low-/intermediate-risk prostate cancer. ADVANCES IN KNOWLEDGE: Multidisciplinary teams may help to select adequately patients to be treated with brachytherapy, with a direct impact on the implant quality and, possibly, on outcome.


Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/mortalidade , Relação Dose-Resposta à Radiação , Humanos , Itália/epidemiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Padrões de Prática Médica , Antígeno Prostático Específico , Neoplasias da Próstata/mortalidade , Dosagem Radioterapêutica , Resultado do Tratamento , Ultrassonografia de Intervenção/métodos
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