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Rotterdam, Netherlands

Mashouf S.,University of Toronto | Lechtman E.,University of Toronto | Lai P.,University of Toronto | Keller B.M.,Sunnybrook Odette Cancer Center | And 3 more authors.
Physics in Medicine and Biology | Year: 2014

Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 ICF formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions. Source

Van De Velde C.J.,Leiden University | Rea D.,University of Birmingham | Seynaeve C.,Erasmus MC Daniel Den Hoed | Putter H.,Leiden University | And 13 more authors.
The Lancet | Year: 2011

Aromatase inhibitors improved disease-free survival compared with tamoxifen when given as an initial adjuvant treatment or after 2-3 years of tamoxifen to postmenopausal women with hormone-receptor-positive breast cancer. We therefore compared the long-term effects of exemestane monotherapy with sequential treatment (tamoxifen followed by exemestane). The Tamoxifen Exemestane Adjuvant Multinational (TEAM) phase 3 trial was conducted in hospitals in nine countries. Postmenopausal women (median age 64 years, range 35-96) with hormone-receptor-positive breast cancer were randomly assigned in a 1:1 ratio to open-label exemestane (25 mg once a day, orally) alone or following tamoxifen (20 mg once a day, orally) for 5 years. Randomisation was by use of a computer-generated random permuted block method. The primary endpoint was disease-free survival (DFS) at 5 years. Main analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, NCT00279448, NCT00032136, and NCT00036270; NTR 267; Ethics Commission Trial 27/2001; and UMIN, C000000057. 9779 patients were assigned to sequential treatment (n=4875) or exemestane alone (n=4904), and 4868 and 4898 were analysed by intention to treat, respectively. 4154 (85) patients in the sequential group and 4186 (86) in the exemestane alone group were disease free at 5 years (hazard ratio 0·97, 95 CI 0·88-1·08; p=0·60). In the safety analysis, sequential treatment was associated with a higher incidence of gynaecological symptoms (942 [20] of 4814 vs 523 [11] of 4852), venous thrombosis (99 [2] vs 47 [1]), and endometrial abnormalities (191 [4] vs 19 [<1]) than was exemestane alone. Musculoskeletal adverse events (2448 [50] vs 2133 [44]), hypertension (303 [6] vs 219 [5]), and hyperlipidaemia (230 [5] vs 136 [3]) were reported more frequently with exemestane alone. Treatment regimens of exemestane alone or after tamoxifen might be judged to be appropriate options for postmenopausal women with hormone-receptor-positive early breast cancer. Pfizer. © 2011 Elsevier Ltd. Source

Van Hezewijk M.,Leiden University | Bastiaannet E.,Leiden University | Putter H.,Leiden University | Scholten A.N.,Leiden University | And 10 more authors.
Radiotherapy and Oncology | Year: 2013

Background and purpose The TEAM trial investigated the efficacy and safety of adjuvant endocrine therapy consisting of either exemestane or the sequence of tamoxifen followed by exemestane in postmenopausal hormone-sensitive breast cancer. The present analyses explored the association between locoregional therapy and recurrence (LRR) in this population. Material and methods Between 2001 and 2006, 9779 patients were randomized. Local treatment was breast conserving surgery plus radiotherapy (BCS + RT), mastectomy without radiotherapy (MST-only), or mastectomy plus radiotherapy (MST + RT). Patients with unknown data on surgery, radiotherapy, tumor or nodal stage (n = 199), and patients treated by lumpectomy without radiotherapy (n = 349) were excluded. Results After a median follow-up of 5.2 years, 270 LRRs occurred (2.9%) among 9231 patients. The 5-years actuarial incidence of LRR was 4.2% (95% CI 3.3-4.9%) for MST-only, 3.4% (95% CI 2.4-4.2%) for MST + RT and 1.9% (95% CI 1.5-2.3%) for BCS + RT. After adjustment for prognostic factors, the hazard ratio (HR, reference BCS + RT) for LRR remained significantly higher for MST-only (HR 1.53; 95% CI 1.10-2.11), not for MST + RT (HR 0.78; 95% CI 0.50-1.22). Conclusion This explorative analysis showed a higher LRR risk after MST-only than after BCS + RT, even after adjustment for prognostic factors. As this effect was not seen for MST + RT versus BCS + RT, it might be explained by the beneficial effects of radiation treatment. © 2013 Elsevier Ireland Ltd. All rights reserved. Source

van der Holt B.,Data Center | Cornelissen J.J.,Erasmus MC Daniel Den Hoed
Thrombosis and Haemostasis | Year: 2013

Treatment of acute lymphoblastic leukaemia (ALL) is frequently complicated by venous thromboembolism (VTE). The efficacy and optimal approach of VTE prevention are unclear, particularly in adult patients. We assessed the effect of thromboprophylaxis on symptomatic VTE incidence in cycle 1 of ALL treatment in adult patients. Secondly, we explored potential etiologic factors for VTE and the clinical impact of VTE on ALL outcome. We retrospectively assessed symptomatic VTE incidence and use of thromboprophylaxis in 240 adults treated for newly diagnosed ALL in the Dutch-Belgian HOVON-37 multicentre study (1999-2005). Potential etiologic factors were explored by analysis of patient and disease characteristics, impact of VTE on ALL outcome by analysis of complete remission and overall survival rates. Symptomatic VTE was observed in 24 of 240 patients (10%). Thromboprophylaxis differed by centre (prophylactic fresh frozen plasma (FFP) supplementation or no thromboprophylaxis) and was applied only during L-asparaginase in cycle 1. VTE incidence was significantly lower with FFP supplementation than without FFP (6% vs. 19%; adjusted odds ratio [OR] 0.28; 95% confidence interval [CI] 0.10-0.73). FFP did not influence antithrombin or fibrinogen plasma levels. Patients with VTE in cycle 1 had a significantly poorer complete remission rate (adjusted OR 0.18; 95% CI 0.07-0.50), particularly patients with cerebral venous thrombosis (adjusted OR 0.17; 95% CI 0.04-0.65). Our study suggests that prophylactic FFP supplementation effectively reduces symptomatic VTE incidence during ALL treatment in adults. This should be confirmed in a randomised controlled trial. © Schattauer 2013. Source

Rodrigues C.A.,University of Sao Paulo | Rocha V.,University of Sao Paulo | Rocha V.,University of Oxford | Dreger P.,University of Heidelberg | And 19 more authors.
Haematologica | Year: 2014

We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97%, respectively; P<0.0001) and chronic graft-versus-host disease (26% vs. 52%; P=0.0005) were less frequent after unrelated cord blood than after matched unrelated donor, whereas no differences were observed in grade II-IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28%), and relapse or progression (28% vs. 35%) at 36 months. There were also no significant differences in 2- year progression-free survival (43% vs. 58%, respectively) and overall survival (36% vs. 51%) at 36 months. In a multivariate analysis, no differences were observed in the outcomes between the two stem cell sources except for a higher risk of neutrophil engraftment (hazard ratio=2.12; P<0.0001) and chronic graft-versus-host disease (hazard ratio 2.10; P=0.0002) after matched unrelated donor transplant. In conclusion, there was no difference in final outcomes after transplantation between umbilical cord blood and matched unrelated donor transplant. Umbilical cord blood is a valuable alternative for patients with lymphoid malignancies lacking an HLA-matched donor, being associated with lower risk of chronic graft-versus-host disease. © 2013 Ferrata Storti Foundation. Source

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