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1.
Br J Radiol ; 93(1107): 20190879, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31804145

RESUMO

OBJECTIVE: Locally recurrent disease is of increasing concern in (non-)small cell lung cancer [(N)SCLC] patients. Local reirradiation with photons or particles may be of benefit to these patients. In this multicentre in silico trial performed within the Radiation Oncology Collaborative Comparison (ROCOCO) consortium, the doses to the target volumes and organs at risk (OARs) were compared when using several photon and proton techniques in patients with recurrent localised lung cancer scheduled to undergo reirradiation. METHODS: 24 consecutive patients with a second primary (N)SCLC or recurrent disease after curative-intent, standard fractionated radio(chemo)therapy were included in this study. The target volumes and OARs were centrally contoured and distributed to the participating ROCOCO sites. Remaining doses to the OARs were calculated on an individual patient's basis. Treatment planning was performed by the participating site using the clinical treatment planning system and associated beam characteristics. RESULTS: Treatment plans for all modalities (five photon and two proton plans per patient) were available for 22 patients (N = 154 plans). 3D-conformal photon therapy and double-scattered proton therapy delivered significantly lower doses to the target volumes. The highly conformal techniques, i.e., intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), CyberKnife, TomoTherapy and intensity-modulated proton therapy (IMPT), reached the highest doses in the target volumes. Of these, IMPT was able to statistically significantly decrease the radiation doses to the OARs. CONCLUSION: Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. They, however, significantly differ in the dose deposited in the OARs. The therapeutic options, i.e., reirradiation or systemic therapy, need to be carefully weighed and discussed with the patients. ADVANCES IN KNOWLEDGE: Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. In light of the abilities of the various highly conformal techniques to spare specific OARs, the therapeutic options need to be carefully weighed and patients included in the decision-making process.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Recidiva Local de Neoplasia/radioterapia , Órgãos em Risco/efeitos da radiação , Fótons/uso terapêutico , Terapia com Prótons/métodos , Reirradiação/métodos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Conjuntos de Dados como Assunto , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Órgãos em Risco/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Resultado do Tratamento
2.
Int J Radiat Oncol Biol Phys ; 82(1): 175-83, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21075555

RESUMO

PURPOSE: To demonstrate the feasibility of magnetic resonance lymphography (MRL) -guided delineation of a boost volume and an elective target volume for pelvic lymph node irradiation in patients with prostate cancer. The feasibility of irradiating these volumes with a high-dose boost to the MRL-positive lymph nodes in conjunction with irradiation of the prostate using intensity-modulated radiotherapy (IMRT) was also investigated. METHODS AND MATERIALS: In 4 prostate cancer patients with a high risk of lymph node involvement but no enlarged lymph nodes on CT and/or MRI, MRL detected pathological lymph nodes in the pelvis. These lymph nodes were identified and delineated on a radiotherapy planning CT to create a boost volume. Based on the location of the MRL-positive lymph nodes, the standard elective pelvic target volume was individualized. An IMRT plan with a simultaneous integrated boost (SIB) was created with dose prescriptions of 42 Gy to the pelvic target volume, a boost to 60 Gy to the MRL-positive lymph nodes, and 72 Gy to the prostate. RESULTS: All MRL-positive lymph nodes could be identified on the planning CT. This information could be used to delineate a boost volume and to individualize the pelvic target volume for elective irradiation. IMRT planning delivered highly acceptable radiotherapy plans with regard to the prescribed dose levels and the dose to the organs at risk (OARs). CONCLUSION: MRL can be used to select patients with limited lymph node involvement for pelvic radiotherapy. MRL-guided delineation of a boost volume and an elective pelvic target volume for selective high-dose lymph node irradiation with IMRT is feasible. Whether this approach will result in improved outcome for these patients needs to be investigated in further clinical studies.


Assuntos
Adenocarcinoma/radioterapia , Irradiação Linfática/métodos , Linfografia/métodos , Imagem por Ressonância Magnética/métodos , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Adenocarcinoma/diagnóstico por imagem , Meios de Contraste , Dextranos , Estudos de Viabilidade , Humanos , Nanopartículas de Magnetita , Masculino , Órgãos em Risco/efeitos da radiação , Pelve , Projetos Piloto , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos
3.
Clin Genitourin Cancer ; 9(2): 109-14, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21903486

RESUMO

BACKGROUND: High-precision radiotherapy with gold marker implantation is a standard technique for prostate cancer treatment. To provide insight into the beneficial effect of gold markers, the influence on treatment volume and radiation doses to healthy tissues was investigated. PATIENTS AND METHODS: Three consecutive treatment margins were constructed, for 10 patients with localized prostate cancer, to show the reduction of planning target volume (PTV): PTV 10 mm (no markers), PTV 7 mm (markers), and PTV 7/5 mm (markers and online correction). On planning computed tomography (CT) scan, the prostate, bladder, rectal wall, and anal canal were contoured. The treatment volume and radiation doses to surrounding organs were calculated. In 65 patients, with the online protocol and gold markers, late toxicity was evaluated. RESULTS: With gold markers a significant PTV reduction of 27% was achieved (P < .001). Subsequently, radiation dose reductions to the mean of 17% (± 4.5%) to the bladder, 19% (± 4.7%) to the anal canal, and 12% (± 3%) to the rectal wall, respectively were seen (P < .001). With 5-mm posterior margins an additional PTV reduction of 3.7% (P < .001) and total radiation dose reduction to the mean of 24% (± 4%), and 16% (± 4.5%) to anal canal and rectal wall, respectively were seen (P < .001). Late Grade 1-2 genitourinary and gastrointestinal toxicity was seen in 32%, and 33%, respectively. Grade 3 toxicity was less than 10%. CONCLUSIONS: This study showed a significant reduction of treatment volume and radiation doses to healthy tissues with intraprostatic gold markers.


Assuntos
Ouro , Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia (Especialidade)/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Masculino , Radiografia , Radioterapia Conformacional/efeitos adversos
4.
Radiother Oncol ; 101(3): 465-70, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21872953

RESUMO

BACKGROUND AND PURPOSE: To investigate the effect of an endorectal balloon (ERB) on anal wall (Awall) and rectal wall (Rwall) doses in high-dose post-prostatectomy intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: For 20 patients, referred for salvage IMRT after prostatectomy for prostate cancer, two planning CT-scans were performed: one with and one without an air-filled ERB. A planning target volume (PTV) was defined, using international guidelines. Furthermore, the Awall and Rwall were delineated. In both the scans, IMRT plans were generated with a prescribed dose of 70 Gy. The mean dose (D(mean)), maximum dose, minimum dose, and volumes exposed to doses ranging from ≥ 20 to ≥ 70 Gy (V(20)-V(70)) to the Awall and Rwall were calculated. Finally, inner Rwall surface areas exposed to doses ranging from ≥ 20 to ≥ 70 Gy (A(20)-A(70)) were calculated. Dose-parameters were compared between plans with and without ERB. RESULTS: All Awall parameters, except V(70), were significantly reduced by the ERB with an overall D(mean) reduction of 6 Gy. Absolute reductions in dose-volume parameters varied from 5% to 11%. Significantly reduced Rwall V(30), V(40), and A(40) were observed with ERB, irrespective of the target volume size. CONCLUSION: ERB application significantly reduces Awall and to a lesser degree Rwall doses in high-dose post-prostatectomy IMRT.


Assuntos
Canal Anal/efeitos da radiação , Prostatectomia , Neoplasias da Próstata/radioterapia , Radioterapia de Intensidade Modulada/métodos , Reto/efeitos da radiação , Cateterismo , Humanos , Masculino , Neoplasias da Próstata/cirurgia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
5.
Int J Radiat Oncol Biol Phys ; 81(5): 1405-14, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21300472

RESUMO

PURPOSE: To develop a treatment technique for craniospinal irradiation using intensity-modulated radiotherapy (IMRT) with improved dose homogeneity at the field junction(s), increased target volume conformity, and minimized dose to the organs at risk (OARs). METHODS AND MATERIALS: Five patients with high-risk medulloblastoma underwent CT simulation in supine position. For each patient, an IMRT plan with daily intrafractionally modulated junction(s) was generated, as well as a treatment plan based on conventional three-dimensional planning (3DCRT). A dose of 39.6 Gy in 22 daily fractions of 1.8 Gy was prescribed. Dose-volume parameters for target volumes and OARs were compared for the two techniques. RESULTS: The maximum dose with IMRT was <107% in all patients. V<95 and V>107 were <1 cm3 for IMRT compared with 3-9 cm3 for the craniospinal and 26-43 cm3 for the spinal-spinal junction with 3DCRT. These observations corresponded with a lower homogeneity index and a higher conformity index for the spinal planning target volume with IMRT. IMRT provided considerable sparing of acute and late reacting tissues. V75 for the esophagus, gastroesophageal junction, and intestine was 81%, 81%, and 22% with 3DCRT versus 5%, 0%, and 1% with IMRT, respectively. V75 for the heart and thyroid was 42% and 32% vs. 0% with IMRT. CONCLUSION: IMRT with daily intrafractionally modulated junction results in a superior target coverage and junction homogeneity compared with 3DCRT. A significant dose reduction can be obtained for acute as well as late-reacting tissues.


Assuntos
Neoplasias Cerebelares/radioterapia , Irradiação Craniana/métodos , Meduloblastoma/radioterapia , Órgãos em Risco/efeitos da radiação , Lesões por Radiação/prevenção & controle , Radioterapia de Intensidade Modulada/métodos , Coluna Vertebral/efeitos da radiação , Adolescente , Articulação Atlantoccipital/efeitos da radiação , Criança , Pré-Escolar , Fracionamento da Dose de Radiação , Junção Esofagogástrica/efeitos da radiação , Esôfago/efeitos da radiação , Coração/efeitos da radiação , Humanos , Intestinos/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Estômago/efeitos da radiação , Glândula Tireoide/efeitos da radiação , Adulto Jovem
6.
Radiother Oncol ; 93(1): 131-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19523704

RESUMO

BACKGROUND AND PURPOSE: To investigate the anal wall (Awall) sparing effect of an endorectal balloon (ERB) in 3D conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) for prostate cancer. MATERIALS AND METHODS: In 24 patients with localized prostate carcinoma, two planning CT-scans were performed: with and without ERB. A prostate planning target volume (PTV) was defined, and the Awall was delineated, using two different methods. Three-field and 4-field 3D-CRT plans, and IMRT plans were generated with a prescription dose of 78Gy. In 144 treatment plans, the minimum dose (D(min)), maximum dose (D(max)), and mean dose (D(mean)) to the Awall were calculated, as well as the Awall volumes exposed to doses ranging from >or=20Gy to >or=70Gy (V(20)-V(70), respectively). RESULTS: In the 3D-CRT plans, an ERB significantly reduced D(mean), D(max), and V(30)-V(70). For IMRT all investigated dose parameters were significantly reduced by the ERB. The absolute reduction of D(mean) was 12Gy in 3D-CRT and was 7.5Gy in IMRT for both methods of Awall delineation. CONCLUSIONS: Application of an ERB showed a significant Awall sparing effect in both 3D-CRT and IMRT. This may lead to reduced late anal toxicity in prostate radiotherapy.


Assuntos
Adenocarcinoma/radioterapia , Canal Anal/efeitos da radiação , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Adenocarcinoma/patologia , Idoso , Cateterismo , Estudos de Coortes , Relação Dose-Resposta à Radiação , Seguimentos , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Próstata/patologia , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/instrumentação , Radioterapia de Intensidade Modulada/instrumentação , Medição de Risco , Resultado do Tratamento
7.
Int J Radiat Oncol Biol Phys ; 65(1): 291-303, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16618584

RESUMO

PURPOSE: To demonstrate the theoretical feasibility of integrating two functional prostate magnetic resonance imaging (MRI) techniques (dynamic contrast-enhanced MRI [DCE-MRI] and 1H-spectroscopic MRI [MRSI]) into inverse treatment planning for definition and potential irradiation of a dominant intraprostatic lesion (DIL) as a biologic target volume for high-dose intraprostatic boosting with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: In 5 patients, four gold markers were implanted. An endorectal balloon was inserted for both CT and MRI. A DIL volume was defined by DCE-MRI and MRSI using different prostate cancer-specific physiologic (DCE-MRI) and metabolic (MRSI) parameters. CT-MRI registration was performed automatically by matching three-dimensional gold marker surface models with the iterative closest point method. DIL-IMRT plans, consisting of whole prostate irradiation to 70 Gy and a DIL boost to 90 Gy, and standard IMRT plans, in which the whole prostate was irradiated to 78 Gy were generated. The tumor control probability and rectal wall normal tissue complication probability were calculated and compared between the two IMRT approaches. RESULTS: Combined DCE-MRI and MRSI yielded a clearly defined single DIL volume (range, 1.1-6.5 cm3) in all patients. In this small, selected patient population, no differences in tumor control probability were found. A decrease in the rectal wall normal tissue complication probability was observed in favor of the DIL-IMRT plan versus the plan with IMRT to 78 Gy. CONCLUSION: Combined DCE-MRI and MRSI functional image-guided high-dose intraprostatic DIL-IMRT planned as a boost to 90 Gy is theoretically feasible. The preliminary results have indicated that DIL-IMRT may improve the therapeutic ratio by decreasing the normal tissue complication probability with an unchanged tumor control probability. A larger patient population, with more variations in the number, size, and localization of the DIL, and a feasible mechanism for treatment implementation has to be studied to extend these preliminary tumor control and toxicity estimates.


Assuntos
Imagem por Ressonância Magnética/métodos , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos , Meios de Contraste , Estudos de Viabilidade , Ouro , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Projetos Piloto , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Próteses e Implantes , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Reto/efeitos da radiação
8.
Int J Radiat Oncol Biol Phys ; 63(2): 565-76, 2005 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-16168848

RESUMO

PURPOSE: To investigate the dosimetric consequences and rectal wall (Rwall) sparing effect of three different endorectal balloons (ERBs) for three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) for prostate cancer. METHODS AND MATERIALS: In 20 patients, 4 planning computed tomography scans were made: 1 without ERB and 3 with ERB1, ERB2, or ERB3 inserted. Two different planning target volumes were defined: prostate only, and prostate plus seminal vesicles. The 3D-CRT and IMRT planning techniques were used, and the prescription dose was 78 Gy. In 284 treatment plans, the Rwall mean dose, the Rwall normal tissue complication probability, and the absolute Rwall volumes exposed to > or =50 Gy (V(50)) and > or =70 Gy (V(70)) were calculated. For spatial dose distribution analysis, inner rectal wall dose maps and dose surface histograms were generated. RESULTS: Each ERB was tolerated well. In the case of 3D-CRT, each ERB showed a statistically significant reduction of all the measured parameters. ERB2 and ERB3 performed better than ERB1. In IMRT, a statistically significant reduction in the Rwall dose parameters could not be demonstrated for any of the ERBs. For 3D-CRT and IMRT, as a result of the rectal dilation, ranging from 8 to 20 cm in circumference, the ERBs resulted in a reduction of the relative inner Rwall surface exposed to intermediate and high doses. CONCLUSIONS: In 3D-CRT, any ERB showed a significant rectal wall sparing effect. ERB2 and ERB3 were superior to ERB1. For both 3D-CRT and IMRT, a reduction of the relative inner Rwall surface exposed to intermediate and high doses was found, which may lead to reduced late rectal toxicity. Development of user- and patient-friendly ERBs is warranted to increase their acceptability.


Assuntos
Cateterismo/instrumentação , Neoplasias da Próstata/radioterapia , Lesões por Radiação/prevenção & controle , Radioterapia Conformacional/instrumentação , Reto/efeitos da radiação , Cateterismo/métodos , Desenho de Equipamento , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Reto/diagnóstico por imagem , Tomografia Computadorizada por Raios X
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