The value of 18F-FDG PET in three-dimensional conformal radiotherapy of cancer

International Nuclear Information System (INIS)

Lv Huiqing; Zhang Zhongmin; Lv Zhonghong

2006-01-01

Three-dimensional conformal radiotherapy (3D-CRT) is based on an extensive use of modern medical imaging techniques. Delineation of the gross tumor volume and organs at risk constitutes one of the most important phases of conformal radiotherapy procedures. 18 F-fluorodeoxyglucose ( 18 F-FDG) PET possesses greater sensitivity and accuracy in detecting diseased lymph nodes, is an important staging examination for patients considered for radiation treatment with curative intent. 18 F-FDG PET has an important role in delineation of gross tumor volume for patients treated with three-dimensional conformal radiotherapy. (authors)

Results of different modes conformal radiotherapy in treatment of cervical cancer

International Nuclear Information System (INIS)

Baranovs'ka, L.M.; Yivankova, V.S.; Khrulenko, T.V.; Skomorokhova, T.V.; Gorelyina, G.L.

2017-01-01

Development of techniques for cytotoxic treatment applying different modes of conformal radiotherapy, brachytherapy and high-energy (high dose rate - HDR) is one of the promising areas of optimization and efficiency of conservative treatment of patients with regional forms of cervical cancer. At Radiation Oncology Department, National Cancer Institute, 89 patients with stage 2b-3b cervical cancer, aged 29 to 70, underwent examination and combined radiotherapy course. The patients were divided into 2 main groups (56 patients) depending on the mode of developed conformal radiation therapy, and a control group made up by 33 patients (classic, default conformal radiotherapy). Results. Along with external beam radiotherapy, the patients of Group 2 were provided with conformal radiotherapy carried out by means of the linear accelerator of electrons in the mode of enhanced multi fractionation of irradiation dose applied to the small pelvis area (tumor and lymph efflux channels) with the single tumor dose 1.3 Gy twice per day once 4-6 hours up to the total radiation dose of 45 Gy applied to the small pelvis lymph nodes. The patients of Group 1 and the ones of the control group underwent conformal radiotherapy in the mode of standard fractionation applied to the small pelvis area with the single tumor dose of 1.8 Gy up to the total radiation dose of 45 Gy. Conformal radiotherapy was carried out for the patients of Group 1 associated with chemoradiomodifiers (tegafur, cisplatin). At the stage 2 of combined radiotherapy course, all patients underwent HDR brachytherapy via Co60 source in the mode of the single tumor dose of 5 Gy at point A up to the total radiation dose of 35-40 Gy. Therefore, employing accelerated mode of multifractiation in conformal radiotherapy of patients with regional cervical cancer makes it possible to enhance canrcinocidal irradiation doses applied to a tumor, and an interval between radiotherapy fractions provides conditions for initiation of

Could 3-D conformal radiotherapy improve the overall survival for non-small cell lung cancer?

International Nuclear Information System (INIS)

Giraud, P.; Helfre, S.; Lavole, A.; Rosenwald, J.C.; Cosset, J.M.

2002-01-01

The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3-D treatment planning systems, sophisticated immobilization devices and demanding quality assurance and treatment verification. The main goal of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of healthy tissues. These techniques would then allow a further dose escalation increasing local control and survival. Non-small cell lung cancer (NSCLC) is one of the most difficult malignant tumors to be treated. It combines geometrical difficulties due to respiratory motion, and number of low tolerance neighboring organs, and dosimetric difficulties because of the presence of huge inhomogeneities. This localization is an attractive and ambitious example for the evaluation of new techniques. However, the published clinical reports in the last years described very heterogeneous techniques and, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from those conformal radiotherapy techniques. After reviewing the rationale for 3DCRT for NSCLC, this paper will describe the main studies of 3DCRT, in order to evaluate its impact on lung cancer treatment Then the current state-of-the-art of IMRT and the last technical and therapeutic innovations in NSCL will be discussed. (authors)

Helical tomo-therapy in the anal canal cancer: dosimetric comparison with conformal radiotherapy with intensity modulation and classical conformal radiotherapy

International Nuclear Information System (INIS)

Ozsahin, M.; Ugurluer, G.; Ballerini, G.; Letenneur, G.; Zouhair, A.; Mirimanoff, R.O.

2009-01-01

A dosimetry comparison was made between helical tomo-therapy, I.M.R.T. and classical conformal three dimensional radiotherapy for twelve first patients that received a image guided radiotherapy, the toxicity was tackled with a minimum follow-up of fourteen months. In conclusion, the CT-guided radiotherapy allows to save organs at risks superior to I.M.R.T. and conformal radiotherapy and a best homogeneity in the target volume. the toxicity is moderated and the break time is limited. (N.C.)

Selection of the optimal radiotherapy technique for locally advanced hepatocellular carcinoma

International Nuclear Information System (INIS)

Lee, Ik-Jae; Seong, Jinsil; Koom, Woong-Sub; Kim, Yong-Bae; Jeon, Byeong-Chul; Kim, Joo-Ho; Han, Kwang-Hyub

2011-01-01

Various techniques are available for radiotherapy of hepatocellular carcinoma, including three-dimensional conformal radiotherapy, linac-based intensity-modulated radiotherapy and helical tomotherapy. The purpose of this study was to determine the optimal radiotherapy technique for hepatocellular carcinoma. Between 2006 and 2007, 12 patients underwent helical tomotherapy for locally advanced hepatocellular carcinoma. Helical tomotherapy computerized radiotherapy planning was compared with the best computerized radiotherapy planning for three-dimensional conformal radiotherapy and linac-based intensity-modulated radiotherapy for the delivery of 60 Gy in 30 fractions. Tumor coverage was assessed by conformity index, radical dose homogeneity index and moderated dose homogeneity index. Computerized radiotherapy planning was also compared according to the tumor location. Tumor coverage was shown to be significantly superior with helical tomotherapy as assessed by conformity index and moderated dose homogeneity index (P=0.002 and 0.03, respectively). Helical tomotherapy showed significantly lower irradiated liver volume at 40, 50 and 60 Gy (V40, V50 and V60, P=0.04, 0.03 and 0.01, respectively). On the contrary, the dose-volume of three-dimensional conformal radiotherapy at V20 was significantly smaller than those of linac-based intensity-modulated radiotherapy and helical tomotherapy in the remaining liver (P=0.03). Linac-based intensity-modulated radiotherapy showed better sparing of the stomach compared with helical tomotherapy in the case of separated lesions in both lobes (12.3 vs. 24.6 Gy). Helical tomotherapy showed the high dose-volume exposure to the left kidney due to helical delivery in the right lobe lesion. Helical tomotherapy achieved the best tumor coverage of the remaining normal liver. However, helical tomotherapy showed much exposure to the remaining liver at the lower dose region and left kidney. (author)

Patterns of failure in children with medulloblastoma treated with 3D conformal radiotherapy

International Nuclear Information System (INIS)

Skowronska-Gardas, Anna; Chojnacka, Marzanna; Morawska-Kaczynska, Marzena; Perek, Danuta; Perek-Polnik, Marta

2007-01-01

Background and purpose: Craniospinal irradiation for medulloblastoma is one of the most complex techniques employed in radiotherapy. Many reports stress the impact of irradiation quality on survival in these patients. Our report presents the outcome and patterns of failure for 95 patients treated with 3D conformal radiotherapy (3D-CRT). Materials and methods: From 1998 to 2003, 95 children with medulloblastoma received 3D conformal radiotherapy. All of them were previously treated with surgery and chemotherapy. The brain and upper spinal cord were treated with two lateral 6 MV photon fields. In four patients, the cribriform plate was irradiated by the additional field. For primary tumour bed we applied two or three photon beams. Spinal cord was irradiated either with 18-20 MeV electron fields or with a mixed beam. Results: With a median follow-up of 48 months, 32/95 patients suffered a multifocal (21) or isolated (11) recurrence. We evaluated every primary site of failure. In all patients, the recurrence appeared within the isodose level of 95-100%. Conclusions: Patterns of failure in medulloblastoma patients treated with 3D conformal radiotherapy indicated that the relapse was mainly associated with poor response to pre-irradiation chemotherapy. We believe that 3D conformal radiotherapy allows avoiding failures, related to radiotherapy uncertainties

Clinical Applications of 3-D Conformal Radiotherapy

Science.gov (United States)

Miralbell, Raymond

Although a significant improvement in cancer cure (i.e. 20% increment) has been obtained in the last 2-3 decades, 30-40% of patients still fail locally after curative radiotherapy. In order to improve local tumor control rates with radiotherapy high doses to the tumor volume are frequently necessary. Three-dimensional conformal radiation therapy (3-D CRT) is used to denote a spectrum of radiation planning and delivery techniques that rely on three-dimensional imaging to define the target (tumor) and to distinguish it from normal tissues. Modern, high-precision radiotherapy (RT) techniques are needed in order to implement the goal of optimal tumor destruction delivering minimal dose to the non-target normal tissues. A better target definition is nowadays possible with contemporary imaging (computerized tomography, magnetic resonance imaging, and positron emission tomography) and image registration technology. A highly precise dose distributions can be obtained with optimal 3-D CRT treatment delivery techniques such as stereotactic RT, intensity modulated RT (IMRT), or protontherapy (the latter allowing for in-depth conformation). Patient daily set-up repositioning and internal organ immobilization systems are necessary before considering to undertake any of the above mentioned high-precision treatment approaches. Prostate cancer, brain tumors, and base of skull malignancies are among the sites most benefitting of dose escalation approaches. Nevertheless, a significant dose reduction to the normal tissues in the vicinity of the irradiated tumor also achievable with optimal 3-D CRT may also be a major issue in the treatment of pediatric tumors in order to preserve growth, normal development, and to reduce the risk of developing radiation induced diseases such as cancer or endocrinologic disorders.

Indications for quality assurance in conformal radiotherapy in Italy

International Nuclear Information System (INIS)

Banci Buonamici, F.; DE Angelis, C.; Rosi, A.; Tabocchini, M.A.; Iotti, C.; Olmi, P.

2008-01-01

Intensity-Modulated Radiation Therapy (IMRT) is an advanced and promising technique of external beam irradiation. IMRT is able to conform the dose distribution to the 3D tumour shape also for complex geometries, preserving surrounding normal tissues and reducing the probability of side effects. IMRT is a time consuming and complex technique and its use demands high level quality assurance. It is, therefore, very important to define conditions for its utilization. Professionals of Radiotherapy Centres, with experience in the IMRT use, have constituted a multidisciplinary working group with the aim of developing indications in this field. Purpose of the present document is to highlight relevant aspects of the technique, but also to underline the high complexity of the technique, whose implementation requires extreme attention of the staff of Radiotherapy Centres involved [it

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

Energy Technology Data Exchange (ETDEWEB)

De Wagter, C [ed.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions.

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

International Nuclear Information System (INIS)

De Wagter, C.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions

Evaluation of conformal radiotherapy techniques through physics and biologic criteria

International Nuclear Information System (INIS)

Bloch, Jonatas Carrero

2012-01-01

In the fight against cancer, different irradiation techniques have been developed based on technological advances and aiming to optimize the elimination of tumor cells with the lowest damage to healthy tissues. The radiotherapy planning goal is to establish irradiation technical parameters in order to achieve the prescribed dose distribution over the treatment volumes. While dose prescription is based on radiosensitivity of the irradiated tissues, the physical calculations on treatment planning take into account dosimetric parameters related to the radiation beam and the physical characteristics of the irradiated tissues. To incorporate tissue's radiosensitivity into radiotherapy planning calculations can help particularize treatments and establish criteria to compare and elect radiation techniques, contributing to the tumor control and the success of the treatment. Accordingly, biological models of cellular response to radiation have to be well established. This work aimed to study the applicability of using biological models in radiotherapy planning calculations to aid evaluating radiotherapy techniques. Tumor control probability (TCP) was studied for two formulations of the linear-quadratic model, with and without repopulation, as a function of planning parameters, as dose per fraction, and of radiobiological parameters, as the α/β ratio. Besides, the usage of biological criteria to compare radiotherapy techniques was tested using a prostate planning simulated with Monte Carlo code PENELOPE. Afterwards, prostate planning for five patients from the Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto, USP, using three different techniques were compared using the tumor control probability. In that order, dose matrices from the XiO treatment planning system were converted to TCP distributions and TCP-volume histograms. The studies performed allow the conclusions that radiobiological parameters can significantly influence tumor control

Dosimetry comparison of irradiation with conformal radiotherapy, intensity modulated radiotherapy, conformal radiotherapy in stereotactic conditions and robotic stereotactic radiotherapy for benign brain tumours

International Nuclear Information System (INIS)

Spasic, E.; Noel, A.; Buchheit, I.; Bernier, V.

2011-01-01

Purpose. - To compare several techniques in order to determine the best treatment for benign brain tumours. Methods and patients. - A retrospective study was performed for five patients who received 3D-conformal radiotherapy, intensity modulated radiotherapy or CyberKnife R . These patients had a meningioma, a pituitary tumour, a cranio-pharyngioma or a neurinoma. In each case, these treatment plans were optimised and compared with the three other dosimetries. Radiobiological or positioning parameters were evaluated, as well as dosimetric parameters, in order to compare treatments with different characteristics. Results. - The dosimetric parameters showed that the choice of treatment seemed to be determined mostly by tumour size, shape and proximity with organs at risk (not tumour localisation). Whereas the results showed no significant deviations with regards to the radiobiological parameters. Therefore, with these parameters, it was difficult to give priority to a treatment. Conclusions. - With regards to benign brain tumours of medium or large size, intensity modulated radiotherapy seemed the recommended treatment. It enabled to obtain a good ratio between efficacy and toxicity for tumours that are really close to organs at risk. Concerning small benign brain tumours, the CyberKnife R was probably the best treatment. (authors)

A computer-controlled conformal radiotherapy system I: overview

International Nuclear Information System (INIS)

Fraass, Benedick A.; McShan, Daniel L.; Kessler, Marc L.; Matrone, Gwynne M.; Lewis, James D.; Weaver, Tamar A.

1995-01-01

Purpose: Equipment developed for use with computer-controlled conformal radiotherapy (CCRT) treatment techniques, including multileaf collimators and/or computer-control systems for treatment machines, are now available. The purpose of this work is to develop a system that will allow the safe, efficient, and accurate delivery of CCRT treatments as routine clinical treatments, and permit modifications of the system so that the delivery process can be optimized. Methods and Materials: The needs and requirements for a system that can fully support modern computer-controlled treatment machines equipped with multileaf collimators and segmental or dynamic conformal therapy capabilities have been analyzed and evaluated. This analysis has been used to design and then implement a complete approach to the delivery of CCRT treatments. Results: The computer-controlled conformal radiotherapy system (CCRS) described here consists of a process for the delivery of CCRT treatments, and a complex software system that implements the treatment process. The CCRS system described here includes systems for plan transfer, treatment delivery planning, sequencing of the actual treatment delivery process, graphical simulation and verification tools, as well as an electronic chart that is an integral part of the system. The CCRS system has been implemented for use with a number of different treatment machines. The system has been used clinically for more than 2 years to perform CCRT treatments for more than 200 patients. Conclusions: A comprehensive system for the implementation and delivery of computer-controlled conformal radiation therapy (CCRT) plans has been designed and implemented for routine clinical use with multisegment, computer-controlled, multileaf-collimated conformal therapy. The CCRS system has been successfully implemented to perform these complex treatments, and is considered quite important to the clinical use of modern computer-controlled treatment techniques

Conformal intensity-modulated radiotherapy (IMRT) delivered by robotic linac-conformality versus efficiency of dose delivery

International Nuclear Information System (INIS)

Webb, Steve

2000-01-01

Intensity-modulated radiotherapy (IMRT) may be delivered with a high-energy-photon linac mounted on a robotic gantry and executing a complex trajectory. In a previous paper an inverse-planning technique was developed for such an application. Here the work is extended to demonstrate the dependence of conformality on the size of the elemental pencil beam, on the complexity of the trajectory and on the sampling of azimuth and elevation of the collimated source. The improved conformality of complex trajectories is demonstrated and benchmarked relative to simpler trajectories, more representative of existing non-robotic IMRT techniques. Specifically, by choosing a very fine pencil beam, exquisitely conformal dose distributions have been obtained. Important sampling considerations have been determined. Expressions have been derived for the dosimetry and monitor-unit efficiency of robotic IMRT. Equivalent trajectories were computed for executing the complex robotic trajectories instead by using a conventional linac. The work benchmarks an ideal in IMRT against which more practical and more common techniques may be measured. (author)

An ill-conditioning conformal radiotherapy analysis based on singular values decomposition

International Nuclear Information System (INIS)

Lefkopoulos, D.; Grandjean, P.; Bendada, S.; Dominique, C.; Platoni, K.; Schlienger, M.

1995-01-01

Clinical experience in stereotactic radiotherapy of irregular complex lesions had shown that optimization algorithms were necessary to improve the dose distribution. We have developed a general optimization procedure which can be applied to different conformal irradiation techniques. In this presentation this procedure is tested on the stereotactic radiotherapy modality of complex cerebral lesions treated with multi-isocentric technique based on the 'associated targets methodology'. In this inverse procedure we use the singular value decomposition (SVD) analysis which proposes several optimal solutions for the narrow beams weights of each isocentre. The SVD analysis quantifies the ill-conditioning of the dosimetric calculation of the stereotactic irradiation, using the condition number which is the ratio of the bigger to smaller singular values. Our dose distribution optimization approach consists on the study of the irradiation parameters influence on the stereotactic radiotherapy inverse problem. The adjustment of the different irradiation parameters into the 'SVD optimizer' procedure is realized taking into account the ratio of the quality reconstruction to the time calculation. It will permit a more efficient use of the 'SVD optimizer' in clinical applications for real 3D lesions. The evaluation criteria for the choice of satisfactory solutions are based on the dose-volume histograms and clinical considerations. We will present the efficiency of ''SVD optimizer'' to analyze and predict the ill-conditioning in stereotactic radiotherapy and to recognize the topography of the different beams in order to create optimal reconstructed weighting vector. The planification of stereotactic treatments using the ''SVD optimizer'' is examined for mono-isocentrically and complex dual-isocentrically treated lesions. The application of the SVD optimization technique provides conformal dose distribution for complex intracranial lesions. It is a general optimization procedure

Metallic stent and stereotactic conformal radiotherapy for hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Li Yu; Wang Ning; Tian Qihe; Guo Zhanwen; Zhang Haibo; Song Liyan

2005-01-01

Objective: To evaluate the effect of metallic stent combined with stereotactic conformal radiotherapy (SCRT) for hilar cholangiocarcinoma. Methods: Fifty-four patients with hilar cholangiocarcinoma were analyzed, including 31 treated with stent plus stereotactic conformal radiotherapy (combined group) and 23 with metallic stent alone (control group). Results: The mean survival time of combined group was 11.1 ± 4.6 months, compared with 5.1 ± 2.8 months of the control group, giving a significant difference between the two groups (P<0.01). Conclusion: The combination of metallic stent and stereotactic conformal radiotherapy is more effective than metallic stent alone for unresectable hilar cholangiocarcinoma. (authors)

Magnetic Resonance Imaging and conformal radiotherapy: Characterization of MRI alone simulation for conformal radiotherapy. Development and evaluation of an automatic volumes of interest segmentation tool for prostate cancer radiotherapy

International Nuclear Information System (INIS)

Pasquier, David

2006-01-01

Radiotherapy is a curative treatment of malignant tumours. Radiotherapy techniques considerably evolved last years with the increasing integration of medical images in conformal radiotherapy. This technique makes it possible to elaborate a complex ballistics conforming to target volume and sparing healthy tissues. The examination currently used to delineate volumes of interest is Computed Tomography (CT), on account of its geometrical precision and the information that it provides on electronic densities needed to dose calculation. Magnetic Resonance Imaging (MRI) ensures a more precise delineation of target volumes in many locations, such as pelvis and brain. For pelvic tumours, the use of MRI needs image registration, which complicates treatment planning and poses the problem of the lack of in vivo standard method of validation. The obstacles in the use of MRI alone in treatment planning were evaluated. Neither geometrical distortion linked with the system and the patient nor the lack of information on electronic densities represent stumbling obstacles. Distortion remained low even in edge of large field of view on modern machines. The assignment of electronic densities to bone structures and soft tissues in MR images permitted to obtain equivalent dosimetry to that carried out on the original CT, with a good reproducibility and homogeneous distribution within target volume. The assignment of electronic densities could not be carried out using 20 MV photons and suitable ballistics. The development of Image Guided Radiotherapy could facilitate the use of MRI alone in treatment planning. Target volumes and organ at risk delineation is a time consuming task in radiotherapy planning. We took part in the development and evaluated a method of automatic and semi automatic delineation of volumes of interest from MRI images for prostate cancer radiotherapy. For prostate and organ at risk automatic delineation an organ model-based method and a seeded region growing method

Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy.

Science.gov (United States)

Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

2016-02-27

Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

2016-01-01

Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

Transition from 2-D radiotherapy to 3-D conformal and intensity modulated radiotherapy

International Nuclear Information System (INIS)

2008-05-01

in number in the near future. Since these treatment techniques are perceived as the cutting-edge of development in the field, there is a concern that centres and countries need orientation as to the preparatory conditions and resources involved. In addition the current status of the evidence supporting the use of IMRT in terms of patient outcomes has to be kept in mind when planning to invest in these technologies. To respond to the needs of Member States to establish the guidelines for the transition from 2-D radiotherapy through 3-D CRT to IMRT several consultants and advisory group meetings were convened to discuss the necessary steps and the milestones for the transfer from 2-D to 3-D conformal radiotherapy and to IMRT. As a result, the present report serves as complementary recommendations to an IAEA recent publication on setting-up a basic radiotherapy programme. Both reports provide a comprehensive overview of the required radiotherapy infrastructure and processes for a broad spectrum of radiotherapy services. The current publication is addressed to those professionals and administrators involved in the development, implementation and management of radiation oncology programmes who seek to improve the conventional approach with the aim of achieving higher precision by transition from simpler radiation treatment approaches to advanced radiotherapy. This report provides the guidelines and highlights the milestones to be achieved by radiotherapy centres in the transition from 2-D to 3-D treatment planning and delivery and further, in transitioning to IMRT. These guidelines and milestones facilitate the process and represent continuation of the work at the IAEA for providing access to safer and better quality treatment for the steadily increasing number of cancer patients in Member States

Pelvic Ewing sarcomas. Three-dimensional conformal vs. intensity-modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Mounessi, F.S.; Lehrich, P.; Haverkamp, U.; Eich, H.T. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Willich, N. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Universitaetsklinikum Muenster (Germany). RiSK - Registry for the Evaluation of Late Side Effects after Radiotherapy in Childhood and Adolescence; Boelling, T. [Center for Radiation Oncology, Osnabrueck (Germany)

2013-04-15

The goal of the present work was to assess the potential advantage of intensity-modulated radiotherapy (IMRT) over three-dimensional conformal radiotherapy (3D-CRT) planning in pelvic Ewing's sarcoma. A total of 8 patients with Ewing sarcoma of the pelvis undergoing radiotherapy were analyzed. Plans for 3D-CRT and IMRT were calculated for each patient. Dose coverage of the planning target volume (PTV), conformity and homogeneity indices, as well as further parameters were evaluated. Results The average dose coverage values for PTV were comparable in 3D-CRT and IMRT plans. Both techniques had a PTV coverage of V{sub 95} > 98 % in all patients. Whereas the IMRT plans achieved a higher conformity index compared to the 3D-CRT plans (conformity index 0.79 {+-} 0.12 vs. 0.54 {+-} 0.19, p = 0.012), the dose distribution across the target volumes was less homogeneous with IMRT planning than with 3D-CRT planning. This difference was statistically significant (homogeneity index 0.11 {+-} 0.03 vs. 0.07 {+-} 0.0, p = 0.035). For the bowel, D{sub mean} and D{sub 1%}, as well as V{sub 2} to V{sub 60} were reduced in IMRT plans. For the bladder and the rectum, there was no significant difference in D{sub mean}. However, the percentages of volumes receiving at least doses of 30, 40, 45, and 50 Gy (V{sub 30} to V{sub 50}) were lower for the rectum in IMRT plans. The volume of normal tissue receiving at least 2 Gy (V{sub 2}) was significantly higher in IMRT plans compared with 3D-CRT, whereas at high dose levels (V{sub 30}) it was significantly lower. Compared to 3D-CRT, IMRT showed significantly better results regarding dose conformity (p = 0.012) and bowel sparing at dose levels above 30 Gy (p = 0.012). Thus, dose escalation in the radiotherapy of pelvic Ewing's sarcoma can be more easily achieved using IMRT. (orig.)

Intensity modulated conformal radiotherapy

International Nuclear Information System (INIS)

Noel, Georges; Moty-Monnereau, Celine; Meyer, Aurelia; David, Pauline; Pages, Frederique; Muller, Felix; Lee-Robin, Sun Hae; David, Denis Jean

2006-12-01

This publication reports the assessment of intensity-modulated conformal radiotherapy (IMCR). This assessment is based on a literature survey which focussed on indications, efficiency and safety on the short term, on the risk of radio-induced cancer on the long term, on the role in the therapeutic strategy, on the conditions of execution, on the impact on morbidity-mortality and life quality, on the impact on the health system and on public health policies and program. This assessment is also based on the opinion of a group of experts regarding the technical benefit of IMCR, its indications depending on the cancer type, safety in terms of radio-induced cancers, and conditions of execution. Before this assessment, the report thus indicates indications for which the use of IMCR can be considered as sufficient or not determined. It also proposes a technical description of IMCR and helical tomo-therapy, discusses the use of this technique for various pathologies or tumours, analyses the present situation of care in France, and comments the identification of this technique in foreign classifications

External beam radiotherapy of localized prostatic adenocarcinoma. Evaluation of conformal therapy, field number and target margins

International Nuclear Information System (INIS)

Lennernaes, B.; Rikner, G.; Letocha, H.; Nilsson, S.

1995-01-01

The purpose of the present study was to identify factors of importance in the planning of external beam radiotherapy of prostatic adenocarcinoma. Seven patients with urogenital cancers were planned for external radiotherapy of the prostate. Four different techniques were used, viz. a 4-field box technique and four-, five- or six-field conformal therapy set-ups combined with three different margins (1-3 cm). The evaluations were based on the doses delivered to the rectum and the urinary bladder. A normal tissue complication probability (NTCP) was calculated for each plan using Lyman's dose volume reduction method. The most important factors that resulted in a decrease of the dose delivered to the rectum and the bladder were the use of conformal therapy and smaller margins. Conformal therapy seemed more important for the dose distribution in the urinary bladder. Five- and six-field set-ups were not significantly better than those with four fields. NTCP calculations were in accordance with the evaluation of the dose volume histograms. To conclude, four-field conformal therapy utilizing reduced margins improves the dose distribution to the rectum and the urinary bladder in the radiotherapy of prostatic adenocarcinoma. (orig.)

A high-precision system for conformal intracranial radiotherapy

International Nuclear Information System (INIS)

Tome, Wolfgang A.; Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Li Zuofeng

2000-01-01

Purpose: Currently, optimally precise delivery of intracranial radiotherapy is possible with stereotactic radiosurgery and fractionated stereotactic radiotherapy. We report on an optimally precise optically guided system for three-dimensional (3D) conformal radiotherapy using multiple noncoplanar fixed fields. Methods and Materials: The optically guided system detects infrared light emitting diodes (IRLEDs) attached to a custom bite plate linked to the patient's maxillary dentition. The IRLEDs are monitored by a commercially available stereo camera system, which is interfaced to a personal computer. An IRLED reference is established with the patient at the selected stereotactic isocenter, and the computer reports the patient's current position based on the location of the IRLEDs relative to this reference position. Using this readout from the computer, the patient may be dialed directly to the desired position in stereotactic space. The patient is localized on the first day and a reference file is established for 5 different couch positions. The patient's image data are then imported into a commercial convolution-based 3D radiotherapy planning system. The previously established isocenter and couch positions are then used as a template upon which to design a conformal 3D plan with maximum beam separation. Results: The use of the optically guided system in conjunction with noncoplanar radiotherapy treatment planning using fixed fields allows the generation of highly conformal treatment plans that exhibit a high degree of dose homogeneity and a steep dose gradient. To date, this approach has been used to treat 28 patients. Conclusion: Because IRLED technology improves the accuracy of patient localization relative to the linac isocenter and allows real-time monitoring of patient position, one can choose treatment-field margins that only account for beam penumbra and image resolution without adding margin to account for larger and poorly defined setup uncertainty. This

Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique.

Science.gov (United States)

Brodin, N Patrik; Munck af Rosenschöld, Per; Blomstrand, Malin; Kiil-Berthlesen, Anne; Hollensen, Christian; Vogelius, Ivan R; Lannering, Birgitta; Bentzen, Søren M; Björk-Eriksson, Thomas

2014-04-01

We investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy. We included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques. Mean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy-the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%-98%), 81% (51%-95%), and 50% (30%-70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%-100%), 90% (60%-98%), and 70% (39%-90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique. We estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered.

Conformal radiotherapy for locally advanced juvenile nasopharyngeal angio-fibroma

Directory of Open Access Journals (Sweden)

Supriya Mallick

2015-01-01

Full Text Available Purpose: To assess the efficacy of radiation in the treatment of juvenile nasopharyngeal angiofibroma (JNA. Materials and Methods: Data were retrieved for JNA treated with radiotherapy from 1987-2012. The demographics, treatment and outcome data were recorded in predesigned proforma. Results: Data of 32 patients were retrieved. Median age was 17 years (range: 12-33 years. All patients received radiation because of refractory, residual or unresectable locally advanced disease. All patients were planned with a three-dimensional conformal technique (3DCRT. The median radiation dose was 30 Gray (range: 30-45 Gray. Median follow-up was 129 months (range: 1-276 months. At the last follow-up, 13 patients were found to have a radiological complete response. Two patients progressed 38 and 43 months after completion of treatment and opted for alternative treatment. One patient developed squamous cell carcinoma of the nasal ale 15 years after radiation. Conclusion: Conformal radiotherapy shows promise as an alternative treatment approach for locally advanced JNA and confers long-term disease control with minimal toxicity.

Extracranial stereotactic radiotherapy: Evaluation of PTV coverage and dose conformity

International Nuclear Information System (INIS)

Haedinger, U.; Thiele, W.; Wulf, J.

2002-01-01

During the past few years the concept of cranial sterotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3%±2.3% (lung), 95.0%±4.5% (liver), and 92.1%±5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73±0.09 (lung), 0.77±0.10 (liver), and 0.70±0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields. (orig.) [de

Conformal radiotherapy using multileaf collimation: quality assurance and in vivo dosimetry

Energy Technology Data Exchange (ETDEWEB)

Aletti, P [Centre A. Vautrin, Nancy (France)

1995-12-01

The application of quality assurance principles in three dimensional conformal therapy is discussed.Critical requirements in three dimensional radiotherapy are the patient immobilization, the location, and the delivered dose. General recommendations with respect to the equipment for conformal radiotherapy and personnel are made.

Conformal radiotherapy using multileaf collimation: quality assurance and in vivo dosimetry

International Nuclear Information System (INIS)

Aletti, P.

1995-01-01

The application of quality assurance principles in three dimensional conformal therapy is discussed.Critical requirements in three dimensional radiotherapy are the patient immobilization, the location, and the delivered dose. General recommendations with respect to the equipment for conformal radiotherapy and personnel are made

Bladder radiotherapy treatment: A retrospective comparison of 3-dimensional conformal radiotherapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy plans

Energy Technology Data Exchange (ETDEWEB)

Pasciuti, Katia, E-mail: k.pasciuti@virgilio.it [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Kuthpady, Shrinivas [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Anderson, Anne; Best, Bronagh [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Waqar, Saleem; Chowdhury, Subhra [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

2017-04-01

To examine tumor's and organ's response when different radiotherapy plan techniques are used. Ten patients with confirmed bladder tumors were first treated using 3-dimensional conformal radiotherapy (3DCRT) and subsequently the original plans were re-optimized using the intensity-modulated radiation treatment (IMRT) and volumetric-modulated arc therapy (VMAT)-techniques. Targets coverage in terms of conformity and homogeneity index, TCP, and organs' dose limits, including integral dose analysis were evaluated. In addition, MUs and treatment delivery times were compared. Better minimum target coverage (1.3%) was observed in VMAT plans when compared to 3DCRT and IMRT ones confirmed by a statistically significant conformity index (CI) results. Large differences were observed among techniques in integral dose results of the femoral heads. Even if no statistically significant differences were reported in rectum and tissue, a large amount of energy deposition was observed in 3DCRT plans. In any case, VMAT plans provided better organs and tissue sparing confirmed also by the normal tissue complication probability (NTCP) analysis as well as a better tumor control probability (TCP) result. Our analysis showed better overall results in planning using VMAT techniques. Furthermore, a total time reduction in treatment observed among techniques including gantry and collimator rotation could encourage using the more recent one, reducing target movements and patient discomfort.

Towards multidimensional radiotherapy (MD-CRT): biological imaging and biological conformality

International Nuclear Information System (INIS)

Ling, C. Clifton; Humm, John; Larson, Steven; Amols, Howard; Fuks, Zvi; Leibel, Steven; Koutcher, Jason A.

2000-01-01

Purpose: The goals of this study were to survey and summarize the advances in imaging that have potential applications in radiation oncology, and to explore the concept of integrating physical and biological conformality in multidimensional conformal radiotherapy (MD-CRT). Methods and Materials: The advances in three-dimensional conformal radiotherapy (3D-CRT) have greatly improved the physical conformality of treatment planning and delivery. The development of intensity-modulated radiotherapy (IMRT) has provided the 'dose painting' or 'dose sculpting' ability to further customize the delivered dose distribution. The improved capabilities of nuclear magnetic resonance imaging and spectroscopy, and of positron emission tomography, are beginning to provide physiological and functional information about the tumor and its surroundings. In addition, molecular imaging promises to reveal tumor biology at the genotype and phenotype level. These developments converge to provide significant opportunities for enhancing the success of radiotherapy. Results: The ability of IMRT to deliver nonuniform dose patterns by design brings to fore the question of how to 'dose paint' and 'dose sculpt', leading to the suggestion that 'biological' images may be of assistance. In contrast to the conventional radiological images that primarily provide anatomical information, biological images reveal metabolic, functional, physiological, genotypic, and phenotypic data. Important for radiotherapy, the new and noninvasive imaging methods may yield three-dimensional radiobiological information. Studies are urgently needed to identify genotypes and phenotypes that affect radiosensitivity, and to devise methods to image them noninvasively. Incremental to the concept of gross, clinical, and planning target volumes (GTV, CTV, and PTV), we propose the concept of 'biological target volume' (BTV) and hypothesize that BTV can be derived from biological images and that their use may incrementally improve

Clinical Studies on conformal radiotherapy combined with epidermal ...

African Journals Online (AJOL)

in second-line treatment of non-small cell lung cancer ... receptor-tyrosine kinase inhibitor (EGFR-TKI) in the second-line treatment of non-small cell ... were divided into two groups: 106 patients were treated with conformal ... Conformal radiotherapy, Targeted therapy, Survival rate .... regression model was used for survival.

Nasopharynx carcinoma treatment: from the conventional radiotherapy to the conformal radiotherapy with intensity modulation; Traitement du carcinome du nasopharynx: de la radiotherapie conventionnelle a la radiotherapie conformationnelle avec modulation d'intensite

Energy Technology Data Exchange (ETDEWEB)

Mokaouim, K.; Grehange, G.; Truc, G.; Peingnaux, K.; Martin, E.; Zanetta, S.; Bruchon, Y.; Bonnetain, F.; Maingon, P. [Centre Georges-Francois Leclerc, 21 - Dijon (France)

2009-10-15

The objective of this study was to evaluate retrospectively the impact of factors linked to the radiotherapy realisation on the local and locoregional control, the global survival, the survival without disease of patients suffering of naso-pharynx carcinoma. Conclusion: the patients suffering of a nasopharynx carcinoma treated by irradiation associated to chemotherapy have an improved global survival and an improved survival without disease. The conformal radiotherapy with or without modulated intensity reduce the risk of serous otitis, trismus and xerostomia at long term. It seems necessary to realize multi centric studies with a longer period of follow up before asserting the advantages of the I.M.R.T. in comparison to the classical and conformal technique in the treatment of naso-pharynx carcinomas. (N.C.)

Conformal radiotherapy: a glossary

International Nuclear Information System (INIS)

Dubray, B.; Giraud, P.; Beaudre, A.

1999-01-01

Most of the concepts and terms related to conformal radiotherapy were produced by English-speaking authors and eventually validated by international groups of experts, whose working language was also English. Therefore, a significant part of this literature is poorly accessible to the French-speaking radiation oncology community. The present paper gathers the 'official' definitions already published in French, along with propositions for the remaining terms which should be submitted to a more formal and representative validation process. (author)

Factors influencing conformity index in radiotherapy for non-small cell lung cancer.

LENUS (Irish Health Repository)

Brennan, Sinead M

2010-01-01

The radiotherapy conformity index (CI) is a useful tool to quantitatively assess the quality of radiotherapy treatment plans, and represents the relationship between isodose distributions and target volume. A conformity index of unity implies high planning target volume (PTV) coverage and minimal unnecessary irradiation of surrounding tissues. We performed this analysis to describe the CI for lung cancer 3-dimensional conformal radiotherapy (3DCRT) and to identify clinical and technical determinants of CI, as it is not known which factors are associated with good quality 3D conformal radiotherapy treatment planning. Radiotherapy treatment plans from a database of 52 patients with inoperable Stage 1 to 3b lung cancer, on a hypofractionated 3DCRT trial were evaluated. A CI was calculated for all plans using the definition of the ICRU 62:CI = (TV\\/PTV), which is the quotient of the treated volume (TV) and the PTV. Data on patient, tumor, and planning variables, which could influence CI, were recorded and analyzed. Mean CI was 2.01 (range = 1.06-3.8). On univariate analysis, PTV (p = 0.023), number of beams (p = 0.036), medial vs. lateral tumor location (p = 0.016), and increasing tumor stage (p = 0.041) were associated with improved conformity. On multiple regression analysis, factors found to be associated with CI included central vs. peripheral tumor location (p = 0.041) and PTV size (p = 0.058). The term 3DCRT is used routinely in the literature, without any indication of the degree of conformality. We recommend routine reporting of conformity indices. Conformity indices may be affected by both planning variables and tumor factors.

Optimization of Stereotactic Radiotherapy Treatment Delivery Technique for Base-Of-Skull Meningiomas

International Nuclear Information System (INIS)

Clark, Brenda G.; Candish, Charles; Vollans, Emily; Gete, Ermias; Lee, Richard; Martin, Monty; Ma, Roy; McKenzie, Michael

2008-01-01

This study compares static conformal field (CF), intensity modulated radiotherapy (IMRT), and dynamic arcs (DA) for the stereotactic radiotherapy of base-of-skull meningiomas. Twenty-one cases of base-of-skull meningioma (median planning target volume [PTV] = 21.3 cm 3 ) previously treated with stereotactic radiotherapy were replanned with each technique. The plans were compared for Radiation Therapy Oncology Group conformity index (CI) and homogeneity index (HI), and doses to normal structures at 6 dose values from 50.4 Gy to 5.6 Gy. The mean CI was 1.75 (CF), 1.75 (DA), and 1.66 (IMRT) (p 3 , the CI (IMRT) was always superior to CI (DA) and CI (CF). At PTV sizes below 25 cm 3 , there was no significant difference in CI between each technique. There was no significant difference in HI between plans. The total volume of normal tissue receiving 50.4, 44.8, and 5.6 Gy was significantly lower when comparing IMRT to CF and DA plans (p 3 , due to improved conformity and normal tissue sparing, in particular for the brain stem and ipsilateral temporal lobe

Conformal radiotherapy for prostate cancer: contribution of pelvic immobilization and new fiducial markers

International Nuclear Information System (INIS)

Garcia, R.; Oozeer, R.; Le Thanh, H.; Chauvet, B.; Toy, B.J.; Reboul, F.

1997-01-01

To reduce errors in the positioning of patients treated with external conformal radiotherapy for prostate cancer, we evaluated both the use of an immobilization device and new fiducial markers. The immobilization device consisted of an individual mold made of polyurethane foam. Two sets of skin markers located on the anterior tibial surfaces were used to identify the pelvic isocenter. The patient's position was evaluated by orthogonal port film which were then compared with the original simulation film. Results are presented with respect to orthogonal axes. Comparison with classic procedures without immobilization showed that use of the mold and new fiducial markers led to a decrease in set-up errors which were less than 5 mm. With the use of an immobilization device and optimized techniques for patients' positioning, conformal radiotherapy of prostate cancer is more accurate. (authors)

The place of conformal radiotherapy in the routine work: national investigation of SFRO members'opinion

International Nuclear Information System (INIS)

Lagrange, J.L.; Lipinski, F.

2001-01-01

National French investigation of the using of conformal radiotherapy in routine work, has been made in 2001, in 180 radiotherapeutic centers. Eighty responses have been obtained and analyzed. Conformal radiotherapy is used in 88% and virtual simulation in 60% of these centers. There is a heterogeneity in the equipment of these institutions, most of them have one or two machines. The accelerator equipment differs, and the availability of multi-leaf collimators and electronic portal imaging is limited. Actually only eleven centers have IMRT, eight have projects to install. Only six centers have CT-scans, used mainly for simulation. In 75% of centers conformal radiotherapy have been used in the treatment of CNS-tumors, head and neck cancers, prostate, and non-small cell lung carcinoma. If there are more equipment and human facilities to use conformal radiotherapy, this treatment can be proposed to patients with breast cancer, rectal and gynecological tumors. According 90% of responses, all prostatic cancers need conformal radiotherapy. The analysis of routine use of conformal radiotherapy in France shows an important heterogeneity but it seems that there is an agreement with objectives of this treatment. (authors)

Implementation of intensity-modulated conformational radiotherapy for cervical cancers at the Alexis Vautrin Centre

International Nuclear Information System (INIS)

Renard-Oldrini, Sophie

2010-01-01

As platinum salt based concomitant conformational radiotherapy and chemotherapy have been used as a standard treatment for cervical cancers but resulted in digestive and haematological toxicities, this research thesis reports the application of intensity-modulated conformational radiation therapy. After having recalled some epidemiological, anatomical aspects, diagnosis and treatments aspects regarding cervical cancer, the author presents this last treatment technique (principles, benefits, practical implementation). The author discusses results obtained by an experiment during which seven patients have been treated by simple conformational radiation therapy, and four by intensity-modulated conformational radiation therapy. Results are discussed in terms of volumes (clinical target volume, growth target volume, planned target volume), dosimetric results, toxicities (urine and skin), weight loss [fr

Bladder filling variation during conformal radiotherapy for rectal cancer

Science.gov (United States)

Sithamparam, S.; Ahmad, R.; Sabarudin, A.; Othman, Z.; Ismail, M.

2017-05-01

Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients.

Bladder filling variation during conformal radiotherapy for rectal cancer

International Nuclear Information System (INIS)

Sithamparam, S; Ahmad, R; Sabarudin, A; Othman, Z; Ismail, M

2017-01-01

Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients. (paper)

Conventional (2D) Versus Conformal (3D) Techniques in Radiotherapy for Malignant Pediatric Tumors: Dosimetric Perspectives

International Nuclear Information System (INIS)

Ahmad, N.; Attia, G.; Radwan, A.; El-Badawy, S.; El-Ghoneimy, E.

2009-01-01

Objectives: In pediatric radiotherapy, the enhanced radiosensitivity of the developing tissues combined with the high overall survival, raise the possibility of late complications. The present study aims at comparing two dimensional (2D) and three dimensional (3D) planning regarding dose homogeneity within target volume and dose to organs at risk (OARs) to demonstrate the efficacy of 3D in decreasing dose to normal tissue. Material and Methods: Thirty pediatric patients (18 years or less) with different pediatric tumors were planned using 2D and 3D plans. All were CT scanned after proper positioning and immobilization. Structures were contoured; including the planning target volume (PTV) and organs at risk (OARs). Conformal beams were designed and dose distribution analysis was edited to provide the best dose coverage to the PTV while sparing OARs using dose volume histograms (DVHs) of outlined structures. For the same PTVs conventional plans were created using the conventional simulator data (2-4 coplanar fields). Conventional and 3D plans coverage and distribution were compared using the term of V95% (volume of PTV receiving 95% of the prescribed dose), V107% (volume of PTV receiving 107% of the prescribed dose), and conformity index (CI) (volume receiving 90% of the prescribed dose/PTV). Doses received by OARs were compared in terms of mean dose. In children treated for brain lesions, OAR volume received 90% of the dose (V 90%) and OAR score were calculated. Results: The PTV coverage showed no statistical difference between 2D and 3D radiotherapy in terms of V95% or V107%. However, there was more conformity in 3D planning with CI 1.43 rather than conventional planning with CI 1.86 (p-value <0.001). Regarding OARs, 3D planning shows large gain in healthy tissue sparing. There was no statistical difference in mean dose received by each OAR. However, for brain cases, brain stem mean dose and brain V 90% showed better sparing in 3D planning (brain stem mean dose was

Acute and late side-effects of conventional and conformal pelvic radiotherapy for cervical and endometrial cancer

International Nuclear Information System (INIS)

Izmajlowicz, B.; Komafel, J.

2010-01-01

Aim of the study. The purpose of this prospective study was to analyze and compare acute and late side-effects observed in patients with cervical and endometrial cancer treated with conventional 2-dimensional (2D) and conformal 3-dimensional (3D) pelvic radiotherapy. Patients and method. 50 patients treated with conventional pelvic radiotherapy and 50 patients treated with conformal pelvic radiotherapy at the Clinical Department of Gynecological Radiotherapy of the Lower Silesian Oncology Center between November 2004 and October 2005 were entered into a prospective study. We assessed Radiotherapy side-effects according to EORTCIRTOG, performance status according to the WHO, Body Mass Index and hematologic parameters during radiotherapy and one year after treatment. Results. Performance status acc. to the WHO was significantly better in the conformal arm. Anemia and nausea were more frequent in the conventional arm. In both the study groups acute gastrointestinal and genitourinary morbidity was more frequent than late morbidity and performance status was better after than before radiotherapy. Mean BMI was lower after radiotherapy than before treatment. Conclusions. Conformal pelvic radiotherapy in patients with cervical and endometrial cancer is less toxic than conventional pelvic radiotherapy which is also confirmed by the performance status. (authors)

Analysis of the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy

Directory of Open Access Journals (Sweden)

Song-Lin Wang

2017-04-01

Full Text Available Objective: To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy. Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42 and the three-dimensional conformal radiotherapy group (n=42 according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated. Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3 +,CD4 +, and CD4 +/CD8 + were significantly elevated, while CD8 + was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions: The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.

A computer-controlled conformal radiotherapy system. III: graphical simulation and monitoring of treatment delivery

International Nuclear Information System (INIS)

Kessler, Marc L.; McShan, Daniel L.; Fraass, Benedick A.

1995-01-01

Purpose: Safe and efficient delivery of radiotherapy using computer-controlled machines requires new procedures to design and verify the actual delivery of these treatments. Graphical simulation and monitoring techniques for treatment delivery have been developed for this purpose. Methods and Materials: A graphics-based simulator of the treatment machine and a set of procedures for creating and manipulating treatment delivery scripts are used to simulate machine motions, detect collisions, and monitor machine positions during treatment. The treatment delivery simulator is composed of four components: a three-dimensional dynamic model of the treatment machine; a motion simulation and collision detection algorithm, user-interface widgets that mimic the treatment machine's control and readout devices; and an icon-based interface for creating and manipulating treatment delivery scripts. These components are used in a stand-alone fashion for interactive treatment delivery planning and integrated with a machine control system for treatment implementation and monitoring. Results: A graphics-based treatment delivery simulator and a set of procedures for planning and monitoring computer-controlled treatment delivery have been developed and implemented as part of a comprehensive computer-controlled conformal radiotherapy system. To date, these techniques have been used to design and help monitor computer-controlled treatments on a radiotherapy machine for more than 200 patients. Examples using these techniques for treatment delivery planning and on-line monitoring of machine motions during therapy are described. Conclusion: A system that provides interactive graphics-based tools for defining the sequence of machine motions, simulating treatment delivery including collision detection, and presenting the therapists with continual visual feedback from the treatment machine has been successfully implemented for routine clinical use as part of an overall system for computer

Dosimetric Evaluation of Intensity Modulated Radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate Cancer Treatment

Directory of Open Access Journals (Sweden)

Bora Uysal

2013-03-01

Full Text Available Objective: The purpose of this dosimetric study is the targeted dose homogeneity and critical organ dose comparison of 7-field Intensity Modulated Radiotherapy (IMRT and 3-D 4-field conformal radiotherapy. Study Design: Cross sectional study. Material and Methods: Twenty patients with low and moderate risk prostate cancer treated at Gülhane Military Medical School Radiation Oncology Department between January 2009 and December 2009 are included in this study. Two seperate dosimetric plans both for 7-field IMRT and 3D-CRT have been generated for each patient to comparatively evaluate the dosimetric status of both techniques and all the patients received 7-field IMRT. Results: Dose-comparative evaluation of two techniques revealed the superiority of IMRT technique with statistically significantly lower femoral head doses along with reduced critical organ dose-volume parameters of bladder V60 (the volume receiving 60 Gy and rectal V40 (the volume receiving 40 Gy and V60. Conclusion: It can be concluded that IMRT is an effective definitive management tool for prostate cancer with improved critical organ sparing and excellent dose homogenization in target organs of prostate and seminal vesicles.

A comparison of conformal and intensity-modulated techniques for oesophageal radiotherapy

International Nuclear Information System (INIS)

Nutting, Christopher M.; Bedford, James L.; Cosgrove, Vivian P.; Tait, Diana M.; Dearnaley, David P.; Webb, Steve

2001-01-01

Background and purpose: To investigate the potential of intensity-modulated radiotherapy (IMRT) to reduce lung irradiation in the treatment of oesophageal carcinoma with radical radiotherapy. Materials and methods: A treatment planning study was performed to compare two-phase conformal radiotherapy (CFRT) with IMRT in five patients. The CFRT plans consisted of anterior, posterior and bilateral posterior oblique fields, while the IMRT plans consisted of either nine equispaced fields (9F), or four fields (4F) with orientations equal to the CFRT plans. IMRT plans with seven, five or three equispaced fields were also investigated in one patient. Treatment plans were compared using dose-volume histograms and normal tissue complication probabilities. Results: The 9F IMRT plan was unable to improve on the homogeneity of dose to the planning target volume (PTV), compared with the CFRT plan (dose range, 16.9±4.5 (1 SD) vs. 12.4±3.9%; P=0.06). Similarly, the 9F IMRT plan was unable to reduce the mean lung dose (11.7±3.2 vs. 11.0±2.9 Gy; P=0.2). Similar results were obtained for seven, five and three equispaced fields in the single patient studied. The 4F IMRT plan provided comparable PTV dose homogeneity with the CFRT plan (11.8±3.3 vs. 12.4±3.9%; P=0.6), with reduced mean lung dose (9.5±2.3 vs 11.0±2.9 Gy; P=0.001). Conclusions: IMRT using nine equispaced fields provided no improvement over CFRT. This was because the larger number of fields in the IMRT plan distributed a low dose over the entire lung. In contrast, IMRT using four fields equal to the CFRT fields offered an improvement in lung sparing. Thus, IMRT with a few carefully chosen field directions may lead to a modest reduction in pneumonitis, or allow tumour dose escalation within the currently accepted lung toxicity

Comparison of 3DCRT,VMAT and IMRT techniques in metastatic vertebra radiotherapy: A phantom Study

Directory of Open Access Journals (Sweden)

Gedik Sonay

2017-01-01

Full Text Available Vertebra metastases can be seen during the prognosis of cancer patients. Treatment ways of the metastasis are radiotherapy, chemotherapy and surgery. Three-dimensional conformal therapy (3D-CRT is widely used in the treatment of vertebra metastases. Also, Intensity Modulated Radiotherapy (IMRT and Volumetric Arc Therapy (VMAT are used too. The aim of this study is to examine the advantages and disadvantages of the different radiotherapy techniques. In the aspect of this goal, it is studied with a randophantom in Uludag University Medicine Faculty, Radiation Oncology Department. By using a computerized tomography image of the phantom, one 3DCRT plan, two VMAT and three IMRT plans for servical vertebra and three different 3DCRT plans, two VMAT and two IMRT plans for lomber vertebra are calculated. To calculate 3DCRT plans, CMS XiO Treatment System is used and to calculate VMAT and IMRT plans Monaco Treatment Planning System is used in the department. The study concludes with the dosimetric comparison of the treatment plans in the spect of critical organ doses, homogeneity and conformity index. As a result of this study, all critical organ doses are suitable for QUANTEC Dose Limit Report and critical organ doses depend on the techniques which used in radiotherapy. According to homogeneity and conformity indices, VMAT and IMRT plans are better than one in 3DCRT plans in servical and lomber vertebra radiotherapy plans.

Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S.; Malandain, G.

2007-01-01

The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

Initiation of conformal radiotherapy with a multileaf-collimator - An approach to clinical routine

International Nuclear Information System (INIS)

Bannach, B.; Doll, Th.; Pape, H.; Schmitt, G.

1995-01-01

The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in MLC-field-shaping concerning size, position and contour to PTV-projection in beams-eye-view (BEV). Field prescription with defined leaf positions of the MLC-setting for geometrical beam shaping is transferred from TPS via TCP/IP. Patient treatment with complex coplanar and non-coplanar field arrangements is performed with an automatic set-up for gantry and collimator angle position contolled by a verification system. Quality assurance for treatment set-up is gained with a mega-voltage imaging device (MVI / PHILIPS SRI 100). Actual treatment outcome and accurate dose delivery for conformal therapy is verified by intercomparison of geometrical field matching of MVI and digitally reconstructed radiographs (DRR) for each delivered beam in BEV

Dosimetric and Radiobiologic Comparison of 3D Conformal Versus Intensity Modulated Planning Techniques for Prostate Bed Radiotherapy

International Nuclear Information System (INIS)

Koontz, Bridget F.; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I.; Montana, Gustavo S.; Oleson, James R.

2009-01-01

Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy.

Science.gov (United States)

Koontz, Bridget F; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I; Montana, Gustavo S; Oleson, James R

2009-01-01

Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

Clinical Studies on conformal radiotherapy combined with epidermal ...

African Journals Online (AJOL)

Purpose: To study the effect of conformal radiotherapy combined with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in the second-line treatment of non-small cell lung cancer (NSCLC). Methods: A total of 316 patients attending Shanghai Pulmonary Hospital affiliated to Tongji University, were divided ...

Salvage conformal radiotherapy for biochemical recurrent prostate cancer after radical prostatectomy

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Carlos R. Monti

2006-08-01

Full Text Available OBJECTIVE: Assess the results of salvage conformal radiotherapy in patients with biochemical failure after radical prostatectomy and identify prognostic factors for biochemical recurrence and toxicity of the treatment. MATERIALS AND METHODS: From June 1998 to November 2001, 35 patients were submitted to conformal radiotherapy for PSA > 0.2 ng/mL in progression after radical prostatectomy and were retrospectively analyzed. The mean dose of radiation in prostatic bed was of 77.4 Gy (68-81. Variables related to the treatment and to tumor were assessed to identify prognostic factors for biochemical recurrence after salvage radiotherapy. RESULTS: The median follow-up was of 55 months (17-83. The actuarial survival rates free of biochemical recurrence and free of metastasis at a distance of 5 years were 79.7% e 84.7%, respectively. The actuarial global survival rate in 5 years was 96.1%.The actuarial survival rate free of biochemical recurrence in 5 years was 83.3% with PSA pre-radiotherapy 1 and 2 (p = 0.023. Dose > 70 Gy in 30% of the bladder volume implied in more acute urinary toxicity (p = 0.035. The mean time for the development of late urinary toxicity was 21 months (12-51. Dose > 55 Gy in 50% bladder volume implied in more late urinary toxicity (p = 0.018. A patient presented late rectal toxicity of 2nd grade. CONCLUSIONS: Conformal radiotherapy showed to be effective for the control of biochemical recurrence after radical prostatectomy. Patients with pre-therapy PSA < 2 ng/mL have more biochemical control.

High precision conformal radiotherapy employing conservative margins in childhood benign and low-grade brain tumours

International Nuclear Information System (INIS)

Jalali, Rakesh; Budrukkar, Ashwini; Sarin, Rajiv; Sharma, Dayananda S.

2005-01-01

Background and purpose: To report local control and follow up outcome data of high precision conformal radiotherapy in childhood brain tumours. Materials and methods: Between December 1999 and December 2002, 26 children (17 boys and 9 girls, median age 11.5 years) with incompletely excised or recurrent benign and low-grade brain tumours [13 craniopharyngiomas, 11 low-grade gliomas (LGG) and 2 others] were treated with three-dimensional (3D) conformal radiotherapy (CRT) (12 patients) and stereotactic conformal radiotherapy (SCRT) (14 patients). Gross tumour volume (GTV) included neuro-imaging based visible tumour and/or resected tumour bed. Clinical target volume (CTV) consisted of GTV + 5 mm margin and planning target volume (PTV) consisted of additional 5 mm margin for CRT and 2 mm for SCRT. Treatment was delivered with 3-9 conformal fixed fields to a median dose of 54 Gy/30 fractions. Results: The actuarial 2 and 3 year disease free and overall survival was 96 and 100%, respectively (median follow up: 25 months, range 12-47 months). Radiological follow up available in 25 patients revealed complete response in 1, partial regression in 10, stable disease in 13 and progression in 1 patient (within the CTV). One patient with craniopharyngioma on a routine imaging revealed a mild asymptomatic cyst enlargement, which resolved with conservative management. A patient with chiasmatic glioma developed cystic degeneration and hydrocephalus 9 months after SCRT requiring cyst drainage and placement of a ventriculoperitoneal shunt. Conclusion: High-precision conformal techniques delivering irradiation to a computer generated target volume employing 7-10 mm 3D margins beyond the visible tumour and/or resected tumour bed appear to be safe in children with incompletely resected or recurrent benign and low-grade brain tumours, based on these data

Three dimensional conformal postoperative radiotherapy for ...

African Journals Online (AJOL)

Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radiotherapy techniques. However they irradiate differently the surrounding organs at risk (OARs) in particular the cochlea, oral cavity & contralateral parotid causing significant increase in the risk of oral mucositis, xerostomia, and ...

Fractionated stereotactic conformal radiotherapy following conservative surgery in the control of craniopharyngiomas

International Nuclear Information System (INIS)

Minniti, Giuseppe; Saran, Frank; Traish, Daphne; Soomal, Rubin; Sardell, Susan; Gonsalves, Adam; Ashley, Susan; Warrington, Jim; Burke, Kevin; Mosleh-Shirazi, Amin; Brada, Michael

2007-01-01

Purpose: To describe the technique and results of stereotactically guided conformal radiotherapy (SCRT) in patients with craniopharyngioma after conservative surgery. Methods and materials: Thirty-nine patients with craniopharyngioma aged 3-68 years (median age 18 years) were treated with SCRT between June 1994 and January 2003. All patients were referred for radiotherapy after undergoing one or more surgical procedures. Treatment was delivered in 30-33 daily fractions over 6-6.5 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. Results: At a median follow-up of 40 months (range 3-88 months) the 3- and 5-year progression-free survival (PFS) was 97% and 92%, and 3- and 5-year survival 100%. Two patients required further debulking surgery for progressive disease 8 and 41 months after radiotherapy. Twelve patients (30%) had acute clinical deterioration due to cystic enlargement of craniopharyngioma following SCRT and required cyst aspiration. One patient with severe visual impairment prior to radiotherapy had visual deterioration following SCRT. Seven out of 10 patients with a normal pituitary function before SCRT had no endocrine deficits following treatment. Conclusion: SCRT as a high-precision technique of localized RT is suitable for the treatment of incompletely excised craniopharyngioma. The local control, toxicity and survival outcomes are comparable to results reported following conventional external beam RT. Longer follow-up is required to assess long-term efficacy and toxicity, particularly in terms of potential reduction in treatment related late toxicity

Intensity-Modulated Radiotherapy versus 3-Dimensional Conformal Radiotherapy Strategies for Locally Advanced Non-Small-Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Uğur Selek

2014-12-01

Full Text Available Chemoradiotherapy is the current standard of care in patients with advanced inoperable stage IIIA or IIIB non-small cell lung cancer (NSCLC. Three-dimensional radiotherapy (3DCRT has been a trusted method for a long time and has well-known drawbacks, most of which could be improved by Intensity Modulated Radiotherapy (IMRT. IMRT is not currently the standard treatment of locally advanced NSCLC, but almost all patients could benefit to a degree in organ at risk sparing, dose coverage conformality, or dose escalation. The most critical step for a radiation oncology department is to strictly evaluate its own technical and physical capabilities to determine the ability of IMRT to deliver an optimal treatment plan. This includes calculating the internal tumor motion (ideally 4DCT or equivalent techniques, treatment planning software with an up-to-date heterogeneity correction algorithm, and daily image guidance. It is crucial to optimise and individualise the therapeutic ratio for each patient during the decision of 3DCRT versus IMRT. The current literature rationalises the increasing use of IMRT, including 4D imaging plus PET/CT, and encourages the applicable knowledge-based and individualised dose escalation using advanced daily image-guided radiotherapy.

Dosimetric study of volumetric arc modulation with RapidArc and intensity-modulated radiotherapy in patients with cervical cancer and comparison with 3-dimensional conformal technique for definitive radiotherapy in patients with cervical cancer

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Guy, Jean-Baptiste [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Falk, Alexander T. [Department of Radiation Oncology, Centre Antoine Lacassagne, Nice (France); Auberdiac, Pierre [Department of Radiation Oncology, Clinique Claude Bernard, Albi (France); Cartier, Lysian; Vallard, Alexis [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Ollier, Edouard [Department of Pharmacology-Toxicology, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Priest en Jarez (France); Trone, Jane-Chloé; Khodri, Moustapha [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Chargari, Cyrus [Department of Radiation Oncology, Hôpital d’instruction de Armées du Val-de-Grâce, Paris (France); Magné, Nicolas, E-mail: nicolas.magne@icloire.fr [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France)

2016-04-01

Introduction: For patients with cervical cancer, intensity-modulated radiation therapy (IMRT) improves target coverage and allows dose escalation while reducing the radiation dose to organs at risk (OARs). In this study, we compared dosimetric parameters among 3-dimensional conformal radiotherapy (3D-CRT), “step-and-shoot” IMRT, and volumetric intensity-modulated arc radiotherapy (VMAT) in a series of patients with cervical cancer receiving definitive radiotherapy. Computed tomography (CT) scans of 10 patients with histologically proven cervical cancer treated with definitive radiation therapy (RT) from December 2008 to March 2010 at our department were selected for this study. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated following the guidelines of the Gyn IMRT consortium that included cervix, uterus, parametrial tissues, and the pelvic nodes including presacral. The median age was 57 years (range: 30 to 85 years). All 10 patients had squamous cell carcinoma with Federation of Gynecology and Obstetrics (FIGO) stage IB-IIIB. All patients were treated by VMAT. OAR doses were significantly reduced for plans with intensity-modulated technique compared with 3D-CRT except for the dose to the vagina. Between the 2 intensity-modulated techniques, significant difference was observed for the mean dose to the small intestine, to the benefit of VMAT (p < 0.001). There was no improvement in terms of OARs sparing for VMAT although there was a tendency for a slightly decreased average dose to the rectum: − 0.65 Gy but not significant (p = 0.07). The intensity modulation techniques have many advantages in terms of quality indexes, and particularly OAR sparing, compared with 3D-CRT. Following the ongoing technologic developments in modern radiotherapy, it is essential to evaluate the intensity-modulated techniques on prospective studies of a larger scale.

Salvage conformal radiotherapy for biochemical recurrent prostate cancer after radical prostatectomy

International Nuclear Information System (INIS)

Monti, Carlos R.; Nakamura, Ricardo A.; Ferrigno, Robson; Rossi Junior, Aristides; Kawakami, Neusa S.; Trevisan, Felipe A.

2006-01-01

Objective: Assess the results of salvage conformal radiotherapy in patients with biochemical failure after radical prostatectomy and identify prognostic factors for biochemical recurrence and toxicity of the treatment. Materials and methods: From June 1998 to November 2001, 35 patients were submitted to conformal radiotherapy for PSA ≥ 0.2 ng/mL in progression after radical prostatectomy and were retrospectively analyzed. The mean dose of radiation in prostatic bed was of 77.4 Gy (68-81). Variables related to the treatment and to tumor were assessed to identify prognostic factors for biochemical recurrence after salvage radiotherapy. Results: The median follow-up was of 55 months (17-83). The actuarial survival rates free of biochemical recurrence and free of metastasis at a distance of 5 years were 79.7% e 84.7%, respectively. The actuarial global survival rate in 5 years was 96.1%.The actuarial survival rate free of biochemical recurrence in 5 years was 83.3% with PSA pre-radiotherapy ≤ 1, 100% when > 1 and ≤ 2, and 57.1% when > 2 (p = 0.023). Dose > 70 Gy in 30% of the bladder volume implied in more acute urinary toxicity (p = 0.035). The mean time for the development of late urinary toxicity was 21 months (12-51). Dose > 55 Gy in 50% bladder volume implied in more late urinary toxicity (p = 0.018). A patient presented late rectal toxicity of second grade. Conclusions: Conformal radiotherapy showed to be effective for the control of biochemical recurrence after radical prostatectomy. Patients with pre-therapy PSA < 2 ng/mL have more biochemical control. (author)

Preservation of parotid function with uncomplicated conformal radiotherapy

International Nuclear Information System (INIS)

Maes, Annelies; Weltens, Caroline; Flamen, Patrick; Lambin, Philippe; Bogaerts, Ria; Liu, Xuan; Baetens, Jan; Hermans, Robert; Van den Bogaert, Walter

2002-01-01

Background and purpose: To evaluate (1) parotid function, (2) subjective xerostomia and (3) pattern of relapses after conformal parotid-sparing radiotherapy (RT) for head and neck cancer. (4) To study dose-response curves of parotid glands. Material and methods: From September 1999 to November 2000, 39 head and neck cancer patients requiring bilateral neck RT were treated with a fairly simple conformal RT technique (three-field set-up+anterior lower neck field; two opposed oblique boost fields). The contralateral parotid was spared. Parotid function was assessed by salivary gland scintigraphies performed before, early (median 4 weeks) and late (median 28 weeks) after RT. Xerostomia was monitored by visual analogue scales (VAS) and LENT SOMA scores. Location of locoregional recurrences was studied in relation to the radiation fields. A dose-response curve of parotids was created using logistic regression. Results: (1) Early after RT, on salivary gland scintigraphy, the mean loss of secretion function in the spared parotid was 67% and total in the non-spared. Late after RT, the mean loss remained 19% in the spared and total in the non-spared parotid. Normal excretion function was regained in 75% of the spared parotids. (2) Late after RT, 78% of patients had no, minimal or acceptable subjective xerostomia. (3) No recurrence was seen near the spared parotid (11/39 locoregional recurrences). (4) The dose-response curve of parotids showed that the mean parotid dose should preferentially be ≤20 Gy, to obtain a good chance (≥70%) for preservation of its function on scintigraphy. Conclusions: An easy conformal parotid-sparing RT technique prevents moderate or severe subjective xerostomia in 78% of patients. In the spared parotids, nearly complete to complete recovery is obtained after 6-12 months

Prospective randomized trail on chrono-chemotherapy + late course three dimensional conformal radio-therapy and conventional chemotherapy plus radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Jin Feng; Ouyang Jinling; Dong Hongmin; Wu Weili; Chen Haixia; He Zhihui

2005-01-01

Objective: To compare the therapeutic effects, toxic side effects of late-course three dimensional conformal radiotherapy plus chrono-chemotherapy (DDP + 5-FU/CF) and conventional radiotherapy plus chemotherapy for nasopharyngeal carcinoma (NPC). Methods: Eighty -six NPC patients admitted from Feb. 2001 to Jan. 2002 were divided randomly into two groups: 1. Chrono-chemotherapy + late course three dimensional conformal radiotherapy(CCR) group-44 patients were treated by late course three dimensional conformal radio-therapy plus chrono-chemotherapy, and 2. Routine-chemotherapy-radiotherapy (RCR) group-42 patients were treated by routine chemotherapy plus radiotherapy. The patients in CCR and RCR group were comparable in age, KPS, stage and pathology. All patients were treated by combined chemotherapy and radiotherapy, with chemotherapy stared 2 weeks ahead of radiotherapy. Chemotherapy: Braun pump was used in all drug infusions; 1. CCR group-DDP 80 mg/ m 2 starting from 10:00 until 22:00, 5-Fu 750 mg/d/m 2 starting from 22:00 until 10:00 next day, CF 200 mg/d/m 2 starting from 10:00 every day, infused at normal speed. These drugs were given for 3 days, 14 days as one cycle, totally 2 cycle, and 2. RCR group-with the same drugs at the same total dose, only with the difference being DDP and CF given QD, starting from 10:00 but at the normal speed. 5-Fu was given through-out the day and continuously for 3 days, totally for 2 cycles. Radiotherapy: linear accelerator irradiation was given to either group. Composite facio-cervical field + anterior cervical tangential field to D T 40 Gy/4w, followed by the coned down per-auricular field plus anterior tangential field or β beam irradiation. In CCR group, after D T 40gy/4w, late course 3-dimensional conformal radiotherapy (3DCRT) was used to add D T 30Gy/3w. In RCR group, routine radiotherapy of 40 Gy/w was supplemented with 30 Gy/3w. The total dose in either group was 70 Gy/7w at the nasopharynx, D T 60-70 Gy/6-7w at the

Localized field conformation radiotherapy combined with endocrine therapy for the treatment of prostate cancer

International Nuclear Information System (INIS)

Karasawa, Katsuyuki; Kaizu, Toshihide; Kurosaki, Hiromasa; Tanaka, Yoshiaki

1999-01-01

To improve the quality of life (QOL) of the patients with prostate cancer, we limit the radiotherapy target volume to the prostate and seminal vesicles while using endocrine therapy towards the disease outside the target volume. Radiotherapy technique was rotation conformation technique with computer-controlled multileaf collimators to the total doses of up to 66-70 Gy. Among 145 evaluable cases with the median age of 74, overall and cause-specific 5-year survival rates were 59.3% and 84.1%, respectively, and the relative survival rate of the Stage A-C cases was 100%. The two thirds (33/50) of the deaths were not of prostate cancer. The rate of severe complication was 1.4%. As for QOL, the rate of impotence was 90%, however, the patients' overall satisfaction towards the treatment was 90%. From this analysis, this combined treatment seems beneficial in the treatment of prostate cancer. (author)

Single-arc volumetric-modulated arc therapy (sVMAT) as adjuvant treatment for gastric cancer: Dosimetric comparisons with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)

International Nuclear Information System (INIS)

Wang, Xin; Li, Guangjun; Zhang, Yingjie; Bai, Sen; Xu, Feng; Wei, Yuquan; Gong, Youling

2013-01-01

To compare the dosimetric differences between the single-arc volumetric-modulated arc therapy (sVMAT), 3-dimensional conformal radiotherapy (3D-CRT), and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for gastric cancer as adjuvant radiotherapy. Twelve patients were retrospectively analyzed. In each patient's case, the parameters were compared based on the dose-volume histogram (DVH) of the sVMAT, 3D-CRT, and IMRT plans, respectively. Three techniques showed similar target dose coverage. The maximum and mean doses of the target were significantly higher in the sVMAT plans than that in 3D-CRT plans and in the 3D-CRT/IMRT plans, respectively, but these differences were clinically acceptable. The IMRT and sVMAT plans successfully achieved better target dose conformity, reduced the V 20/30 , and mean dose of the left kidney, as well as the V 20/30 of the liver, compared with the 3D-CRT plans. And the sVMAT technique reduced the V 20 of the liver much significantly. Although the maximum dose of the spinal cord were much higher in the IMRT and sVMAT plans, respectively (mean 36.4 vs 39.5 and 40.6 Gy), these data were still under the constraints. Not much difference was found in the analysis of the parameters of the right kidney, intestine, and heart. The IMRT and sVMAT plans achieved similar dose distribution to the target, but superior to the 3D-CRT plans, in adjuvant radiotherapy for gastric cancer. The sVMAT technique improved the dose sparings of the left kidney and liver, compared with the 3D-CRT technique, but showed few dosimetric advantages over the IMRT technique. Studies are warranted to evaluate the clinical benefits of the VMAT treatment for patients with gastric cancer after surgery in the future

Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

Eldebawy, Eman [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Department of Radiation Oncology, Children' s Cancer Hospital, Cairo (Egypt); Parker, William, E-mail: william.parker@mcgill.ca [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Abdel Rahman, Wamied [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Freeman, Carolyn R. [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada)

2012-03-01

Purpose: To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye. Methods and Materials: Treatment plans for 3 patients with retinoblastoma were developed using 10 radiotherapy techniques including electron beams, photon beam wedge pair (WP), photon beam three-dimensional conformal radiotherapy (3D-CRT), fixed gantry intensity-modulated radiotherapy (IMRT), photon volumetric arc therapy (VMAT), fractionated stereotactic radiotherapy, and helical tomotherapy (HT). Dose-volume analyses were carried out for each technique. Results: All techniques provided similar target coverage; conformity was highest for VMAT, nine-field (9F) IMRT, and HT (conformity index [CI] = 1.3) and lowest for the WP and two electron techniques (CI = 1.8). The electron techniques had the highest planning target volume dose gradient (131% of maximum dose received [D{sub max}]), and the CRT techniques had the lowest (103% D{sub max}) gradient. The volume receiving at least 20 Gy (V{sub 20Gy}) for the ipsilateral bony orbit was lowest for the VMAT and HT techniques (56%) and highest for the CRT techniques (90%). Generally, the electron beam techniques were superior in terms of brain sparing and delivered approximately one-third of the integral dose of the photon techniques. Conclusions: Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.

Intensity modulation in breast radiotherapy: Development of an innovative field-in-field technique at Institut Gustave-Roussy

International Nuclear Information System (INIS)

Heymann, S.; Bourhis, J.; Bourgier, C.; Verstraet, R.; Pichenot, C.; Vergne, E.; Lefkopoulos, D.; Husson, F.; Kafrouni, H.; Mahe, J.; Kandalaft, B.; Marsiglia, H.

2011-01-01

Purpose. - To assess the potential dosimetric gain of pre-segmentation modulated radiotherapy (OAPS, DosiSoft TM ) of breast, compared to routine 3D conformal radiotherapy. Patients and methods. - Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm 3 ; range [100-1049 cm 3 ]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the pre-segmentation algorithm of DosiSoft TM (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V 30 Gy for the heart, and mean dose, V 20 Gy and V 30 Gy for lungs. Results. - Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P TM ) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk. (authors)

Conformal Radiotherapy in the Treatment of Advanced Juvenile Nasopharyngeal Angiofibroma With Intracranial Extension: An Institutional Experience

International Nuclear Information System (INIS)

Chakraborty, Santam; Ghoshal, Sushmita; Patil, Vijay Maruti; Oinam, Arun Singh; Sharma, Suresh C.

2011-01-01

Purpose: To describe the results of conformal radiotherapy in advanced juvenile nasopharyngeal angiofibroma in a tertiary care institution. Methods and Materials: Retrospective chart review was conducted for 8 patients treated with conformal radiotherapy between 2006 and 2009. The median follow-up was 17 months. All patients had Stage IIIB disease with intracranial extension. Radiotherapy was considered as treatment because patients were deemed inoperable owing to extensive intracranial/intraorbital extension or proximity to optic nerve. All but 1 patient were treated with intensity-modulated radiotherapy using seven coplanar fields. Median (range) dose prescribed was 39.6 (30-46) Gy. Actuarial analysis of local control and descriptive analysis of toxicity profile was conducted. Results: Despite the large and complex target volume (median planning target volume, 292 cm 3 ), intensity-modulated radiotherapy achieved conformal dose distributions (median van't Reit index, 0.66). Significant sparing of the surrounding organs at risk was obtained. No significant Grade 3/4 toxicities were experienced during or after treatment. Actual local control at 2 years was 87.5%. One patient died 1 month after radiotherapy secondary to massive epistaxis. The remaining 7 patients had progressive resolution of disease and were symptom-free at last follow-up. Persistent rhinitis was the only significant toxicity, seen in 1 patient. Conclusions: Conformal radiotherapy results in good local control with minimal acute and late side effects in juvenile nasopharyngeal angiofibromas, even in the presence of advanced disease.

Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy

International Nuclear Information System (INIS)

Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

2016-01-01

Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Ten consecutive patients with inoperable chest wall desmoid tumours (PTV range 416–4549 cm 3 ) were selected. For each patient, 3DCRT, IMRT and VMAT plans were generated and the Conformity Index (CI), organ at risk (OAR) doses and monitor unit (MU) were evaluated. The Wilcoxon signed-rank test was used to compare dose delivered to both target and OARs. The mean number of fields for 3DCRT and IMRT were 6.3 ± 2.1, 7.2 ± 1.8. The mean number of arcs for VMAT was 3.7 ± 1.1. The mean conformity index of VMAT (0.98 ± 0.14) was similar to that of IMRT (1.03 ± 0.13), both of which were significantly better than 3DCRT (1.35 ± 0.20; p = 0.005). The mean dose to lung was significantly higher for 3DCRT (11.9Gy ± 7.9) compared to IMRT (9.4Gy ± 5.4, p = 0.014) and VMAT (8.9Gy ± 4.5, p = 0.017). For the 3 females, the low dose regions in the ipsilateral breast for VMAT were generally less with VMAT. IMRT plans required 1427 ± 532 MU per fraction which was almost 4-fold higher than 3DCRT (313 ± 112, P = 0.005). Compared to IMRT, VMAT plans required 60 % less MU (570 ± 285, P = 0.005). For inoperable chest wall desmoid tumours, VMAT delivered equivalent target coverage when compared to IMRT but required 60 % less MU. Both VMAT and IMRT were superior to 3DCRT in terms of better PTV coverage and sparing of lung tissue

Conformal radiotherapy for 6 cases of bile duct carcinoma

International Nuclear Information System (INIS)

Kawasaki, Yoshiyuki; Suzuki, Takashi; Sugahara, Shinji

1998-01-01

Authors performed the conformal radiotherapy using the multileaf collimator for inoperable patients with bile duct carcinoma and examined the usefulness of this treatment. Forty one patients were examined, whose age was from 45 to 80 years (mean: 69.5 years), and whose ratio of men to women was 1 to 1.6. Patients in Group I (palliative irradiation, 30 cases) received bilateral irradiation using the linac with 4 MV-x-ray of total 50.0 Gy (2.0 Gy a dose, 5 times a week), those in Group II (palliative irradiation, 5 cases) using the microtron with 10 MV-x-ray of total 50.0 Gy (2.0 Gy a dose, 5 times a week). And those in Group III (radial irradiation, 6 cases) were first irradiated using the microtron with total 40.0 Gy (2.0 Gy a dose, 5 times a week) and secondly by the conformal radiotherapy with total 20.0 Gy (2.0 Gy a dose, 5 times a week). Patients in Group III were irradiated with total 60.0 Gy. Patients in all Groups showed mild side-effects including nausea and vomiting. And patients in Group III, who were irradiated 10 Gy more than other Group, showed no severe side-effects as alimentary bleeding, liver function disorders and cholangitis. In Group I, one year survivors were 3 (10.0%) and two years survivors were none. The median survival month was 7.2 months. In Group II, one year survivor was 1 (20.0%) and two years survivors were none. The median survival month was 8.1 months. In Group III, one year survivors were 2 (33.3%), and two years survivors were 2 (33.3%). The median survival month was 11.2 months. Two patients are survival at present (March, 1998), 2 years and 10 months, and 2 years and 9 months, respectively. The conformal radiotherapy gave better results than the ordinary radiotherapy. (K.H.)

Hyperfractionated 3D conformal radiotherapy and concurrent chemotherapy for unresectable stage III non-small cell lung cancer

International Nuclear Information System (INIS)

Choi, E.K.; Ahn, S.D.; Yi, B.Y.; Chang, H.S.; Lee, J.H.; Suh, C.W.; Lee, J.S.; Kim, S.H.; Koh, Y.S.; Kim, W.S.; Kim, D.S.; Kim, W.D.; Sohn, K.H.

1997-01-01

Purpose/Objective: This phase II study has been conducted to determine the feasibility, toxicity, response rate, local control, distant metastasis, and survival of hyperfractionated 3D conformal radiotherapy and concurrent chemotherapy with mitomycin C, vinblastine, and cisplatin in unresectable stage III non-small cell lung cancer (NSCLC), and also to find the most ideal 3D conformal radiotherapy technique. Materials and Methods: From Aug 1993, 173 patients with unresectable stage III NSCLC were entered into this trial and 146 (84%) completed the treatment. Hyperfractionated radiotherapy was given to a total dose of 65-70 Gy (120 cGy/fx, bid) with concurrent 2 cycles of MVP chemotherapy (Mitomycin C 6 mg/m 2 d2 and d29, Vinblastine 6 mg/m 2 d2 and d29, Cisplatin 60 mg/m 2 d1 and d28). Of these 146 patients who completed the treatment, 78 received noncoplanar 3D conformal radiotherapy using 4-6 fields and 17 received coplanar segmented conformal radiotherapy. Clinical tumor response was assessed one month after the completion of radiotherapy by computerized tomography (CT) scan. Toxicity was graded by RTOG and SWOG criteria. Normal tissue complication probability (NTCP) for lung was calculated to find the correlation with radiation pneumonitis. Results: Nineteen (13%) had stage IIIa and 127 (87%) had IIIb disease including 16 with pleural effusion and 20 with supraclavicular lymph node metastases. Response rate was 74%, including 20% complete response and 54% partial response. With a minimum follow up of 12 months, overall survival was 60% at 1 year, 30% at 2 years and median survival was 15 months. Patients achieving a complete response (n=29) had a 2-year overall survival of 46.5% compared to 28.7% for partial responders (n=79) (p=.001). Actuarial local control was 66.7% at 1 year and 43.7% at 2 years. Actuarial distant free survival was 52.3% at 1 year and 39.8% at 2 years. Major hematologic toxicity (Gr 3-4) occurred in 33% of the patients but treatment delay

Three-dimensional treatment planning for postoperative radiotherapy in patients with node-positive cervical cancer. Comparison between a conventional and a conformal technique

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Olofsen-van Acht, M.J.J.; Quint, S.; Seven, M.; Berg, H.A. van den; Levendag, P.C. [University Hospital Rotterdam (Netherlands). Dept. of Radiation Oncology; Santvoort, J.P.C. van [University Hospital Rotterdam (Netherlands). Subdivision of Clinical Physics; Logmans, A. [University Hospital Rotterdam (Netherlands). Dept. of Gynecologic Oncology

1999-09-01

Purpose: Reduction of irradiated small bowel volume, using a conformal three-dimensional treatment planning technique in postoperative radiotherapy of cervical cancer patients. Patients and Methods: Large gynecological treatment fields including the para-aortic nodes were analyzed in 15 patients. A conventional treatment plan with anterior and posterior (AP-PA) parallel opposed fields and a 3D 4-field conformal radiotherapy plan with a central blocking of small bowel were compared for each patient. Dose-volume histograms and dose parameters were established. Because of the tolerance constraints of the small bowel, the cumulative dose applied to the target was 48.6 Gy. Results: The mean Tumor Control Probability (TCP) values for both the conventional and the conformal technique were 0.60 and 0.61, respectively, with ranges of 0.56 to 0.67 and 0.57 to 0.66, respectively. The mean volume receiving 95% or more of the prescribed dose (V95) of the small bowel was 47.6% (32.5 to 66.3%) in the AP-PA technique and 14.9% (7.0 to 22.5%) in the conformal technique (p<0.001), indicating a significant reduction in irradiated volume of small bowel in the higher dose range. The mean Normal Tissue Complication Probability (NTCP) decreased from 0.11 to 0.03 with the conformal plan. In patients who received a pedicled omentoplasty during surgery, the mean V95 for small bowel could be reduced to 8.5% (7.0 to 9.9%). The mean median dose to the kidneys was only slightly elevated in the conformal treatment. Especially the mean dose to the right kidney in conventional vs conformal treatment was 3.3 vs 7.9 Gy. The mean near-minimum dose (D95) to the rectosigmoid decreased from 48.4 to 30.1 Gy in the conformal plan compared to the conventional plan. Conclusion: The small bowel dose can be significantly reduced with 3D treatment planning, particularly if a predicled omentoplasty is performed. This allows dose escalation to the tumor region without unacceptable toxicity for the small bowel

Optimisation of radiotherapy for carcinoma of the parotid gland: a comparison of conventional, three-dimensional conformal, and intensity-modulated techniques

International Nuclear Information System (INIS)

Nutting, Christopher M.; Rowbottom, Carl G.; Cosgrove, Vivian P.; Henk, J. Michael; Dearnaley, David P.; Robinson, Martin H.; Conway, John; Webb, Steve

2001-01-01

Background and purpose: To compare external beam radiotherapy techniques for parotid gland tumours using conventional radiotherapy (RT), three-dimensional conformal radiotherapy (3DCRT), and intensity-modulated radiotherapy (IMRT). To optimise the IMRT techniques, and to produce an IMRT class solution. Materials and methods: The planning target volume (PTV), contra-lateral parotid gland, oral cavity, brain-stem, brain and cochlea were outlined on CT planning scans of six patients with parotid gland tumours. Optimised conventional RT and 3DCRT plans were created and compared with inverse-planned IMRT dose distributions using dose-volume histograms. The aim was to reduce the radiation dose to organs at risk and improve the PTV dose distribution. A beam-direction optimisation algorithm was used to improve the dose distribution of the IMRT plans, and a class solution for parotid gland IMRT was investigated. Results: 3DCRT plans produced an equivalent PTV irradiation and reduced the dose to the cochlea, oral cavity, brain, and other normal tissues compared with conventional RT. IMRT further reduced the radiation dose to the cochlea and oral cavity compared with 3DCRT. For nine- and seven-field IMRT techniques, there was an increase in low-dose radiation to non-target tissue and the contra-lateral parotid gland. IMRT plans produced using three to five optimised intensity-modulated beam directions maintained the advantages of the more complex IMRT plans, and reduced the contra-lateral parotid gland dose to acceptable levels. Three- and four-field non-coplanar beam arrangements increased the volume of brain irradiated, and increased PTV dose inhomogeneity. A four-field class solution consisting of paired ipsilateral coplanar anterior and posterior oblique beams (15, 45, 145 and 170 degree sign from the anterior plane) was developed which maintained the benefits without the complexity of individual patient optimisation. Conclusions: For patients with parotid gland tumours

Practical recommendations for breathing-adapted radiotherapy; Bonnes pratiques pour la radiotherapie asservie a la respiration

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Simon, L.; Giraud, P.; Rosenwald, J.C. [Institut Curie, Dept. d' Oncologie-radiotherapie, 75 - Paris (France); Dumas, J.L.; Lorchel, F. [CHU de Besancon, Hopital Jean-Minjoz, Service Radiotherapie, 25 - Besancon (France); Marre, D. [Institut Claudius-Regaud, Dept. des Radiations, 31 - Toulouse (France); Dupont, S. [Hopital Europeen Georges-Pompidou, Service d' Oncoradiotherapie, 75 - Paris (France); Varmenot, N. [Centre Henri-Becquerel, UnitE de Physique Medicale, 76 - Rouen (France); Ginestet, C. [Centre Leon-Berard, Dept. de Radiotherapie, 69 - Lyon (France); Caron, J. [Institut Bergonie, Dept. de Radiotherapie, 33 - Bordeaux (France); Marchesi, V. [Centre Alexis-Vautrin, Dept. de Radiotherapie, 54 - Vandoeuvre-les-Nancy (France); Ferreira, I. [Institut Gustave-Roussy, Dept. d' Oncologie Radiotherapie, 94 - Villejuif (France); Garcia, R. [Institut Sainte-Catherine, Service de Radiotherapie, 84 - Avignon (France)

2007-06-15

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

Set-up error in supine-positioned patients immobilized with two different modalities during conformal radiotherapy of prostate cancer

International Nuclear Information System (INIS)

Fiorino, C.; Cattaneo, G.M.; Calandrino, R.; Reni, M.; Bolognesi, A.; Bonini, A.

1998-01-01

Background: Conformal radiotherapy requires reduced margins around the clinical target volume (CTV) with respect to traditional radiotherapy techniques. Therefore, high set-up accuracy and reproducibility are mandatory. Purpose: To investigate the effectiveness of two different immobilization techniques during conformal radiotherapy of prostate cancer with small fields. Materials and methods: 52 patients with prostate cancer were treated by conformal three- or four-field techniques with radical or adjuvant intent between November 1996 and March 1998. In total, 539 portal images were collected on a weekly basis for at least the first 4 weeks of the treatment on lateral and anterior 18 MV X-ray fields. The average number of sessions monitored per patient was 5.7 (range 4-10). All patients were immobilized with an alpha-cradle system; 25 of them were immobilized at the pelvis level (group A) and the remaining 27 patients were immobilized in the legs (group B). The shifts with respect to the simulation condition were assessed by measuring the distances between the same bony landmarks and the field edges. The global distributions of cranio-caudal (CC), posterior-anterior (PA) and left-right (LR) shifts were considered; for each patient random and systematic error components were assessed by following the procedure suggested by Bijhold et al. (Bijhold J, Lebesque JV, Hart AAM, Vijlbrief RE. Maximising set-up accuracy using portal images as applied to a conformal boost technique for prostatic cancer. Radiother. Oncol. 1992;24:261-271). For each patient the average isocentre (3D) shift was assessed as the quadratic sum of the average shifts in the three directions. Results 5 mm equal to 4.4% with respect to the 21.6% of group A (P<0.0001). This value was also better than the corresponding value found in a previously investigated group of 21 non-immobilized patients (Italia C, Fiorino C, Ciocca M, et al. Quality control by portal film analysis of the conformal radiotherapy

Intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy for high-grade gliomas: Does IMRT increase the integral dose to normal brain?

International Nuclear Information System (INIS)

Hermanto, Ulrich; Frija, Erik K.; Lii, MingFwu J.; Chang, Eric L.; Mahajan, Anita; Woo, Shiao Y.

2007-01-01

Purpose: To determine whether intensity-modulated radiotherapy (IMRT) treatment increases the total integral dose of nontarget tissue relative to the conventional three-dimensional conformal radiotherapy (3D-CRT) technique for high-grade gliomas. Methods and Materials: Twenty patients treated with 3D-CRT for glioblastoma multiforme were selected for a comparative dosimetric evaluation with IMRT. Original target volumes, organs at risk (OAR), and dose-volume constraints were used for replanning with IMRT. Predicted isodose distributions, cumulative dose-volume histograms of target volumes and OAR, normal tissue integral dose, target coverage, dose conformity, and normal tissue sparing with 3D-CRT and IMRT planning were compared. Statistical analyses were performed to determine differences. Results: In all 20 patients, IMRT maintained equivalent target coverage, improved target conformity (conformity index [CI] 95% 1.52 vs. 1.38, p mean by 19.8% and D max by 10.7%), optic chiasm (D mean by 25.3% and D max by 22.6%), right optic nerve (D mean by 37.3% and D max by 28.5%), and left optic nerve (D mean by 40.6% and D max by 36.7%), p ≤ 0.01. This was achieved without increasing the total nontarget integral dose by greater than 0.5%. Overall, total integral dose was reduced by 7-10% with IMRT, p < 0.001, without significantly increasing the 0.5-5 Gy low-dose volume. Conclusions: These results indicate that IMRT treatment for high-grade gliomas allows for improved target conformity, better critical tissue sparing, and importantly does so without increasing integral dose and the volume of normal tissue exposed to low doses of radiation

Brainstem tolerance to conformal radiotherapy of skull base tumors

International Nuclear Information System (INIS)

Debus, J.; Hug, E.B.; Munzenrider, J.E.; Liebsch, N.J.; O'Farrell, D.; Efird, J.; Daly, W.; Suit, H.D.

1996-01-01

Purpose/Objective: Brainstem tolerance to inhomogenous radiation doses applied by modern conformal radiotherapy has not yet been examined. The aim of this study was to analyse the incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy. Materials and Methods: Between 1974 and 1995, 367 patients with chordomas (n=195) and chondrosarcomas (n=172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. All patients had previously undergone biopsy, subtotal or total tumor removal. 104 patients had two or more surgical procedures before radiotherapy. Following 3D treatment planning with delineation of target volumes and critical non-target structures, dose distributions and dose volume histograms were calculated [at the time of treatment delivery]. Radiotherapy was given once a day, 1.8 Gy or CGE (Cobalt Gy Equivalent: Proton Gy X 1.1) per fraction, 5 fractions per week, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to ≤64 CGE and to the brainstem center to ≤53 CGE. Dose distributions were developed to limit dose to brainstem surface and center; current plans limit dose to surface and center to ≤64 CGE and ≤53 CGE, respectively. Brainstem toxicity was scored according to the RTOG grading system. Results: Follow-up ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem symptoms, attributable to the treatment, developed in 17 of 282 patients with local tumor control (6.0%), resulting in death of three patients. The mean time to onset of symptoms was 17 months (range: 4.5 to 177 months). These symptoms appeared in 89.5% within 3 years. Grading of the brainstem toxicity is listed in table 1. Actuarial rates of 5 and 10 year toxicity free survival were 87% and 82% respectively. Increased risk of brainstem toxicity was significantly associated with maximum brainstem dose

Practical recommendations for breathing-adapted radiotherapy

International Nuclear Information System (INIS)

Simon, L.; Giraud, P.; Rosenwald, J.C.; Dumas, J.L.; Lorchel, F.; Marre, D.; Dupont, S.; Varmenot, N.; Ginestet, C.; Caron, J.; Marchesi, V.; Ferreira, I.; Garcia, R.

2007-01-01

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

Breathing adapted radiotherapy: final clinic results of the program for the support to costly innovating techniques (Stic) of 2003

International Nuclear Information System (INIS)

Giraud, P.; Giraud, P.; Morvan, E.; Djadi-Prat, J.; Rosenwald, J.C.; Carrere, M.O.

2010-01-01

The authors report the comparison, from a clinic point of view, between breathing adapted conformational radiotherapy (BART) and conventional conformational radiotherapy, in the case of lung and breast cancers. The assessment comprised a clinic examination, a thoracic radiography, breathing functional tests, a thoracic scanography at different moments (3, 6, 12, 18 and 24 months), and dosimetric criteria for tumour target volumes and the different thoracic organs at risk. Data have been collected among more than six hundred patients. Breathing adapted techniques allow acute and late toxicity to be reduced, notably for the lung, heart and oesophagus during a lung irradiation. They are less interesting for mammary irradiation, but could be important for a radiotherapy of the left breast. Short communication

Estimating the costs of intensity-modulated and 3-dimensional conformal radiotherapy in Ontario.

Science.gov (United States)

Yong, J H E; McGowan, T; Redmond-Misner, R; Beca, J; Warde, P; Gutierrez, E; Hoch, J S

2016-06-01

Radiotherapy is a common treatment for many cancers, but up-to-date estimates of the costs of radiotherapy are lacking. In the present study, we estimated the unit costs of intensity-modulated radiotherapy (imrt) and 3-dimensional conformal radiotherapy (3D-crt) in Ontario. An activity-based costing model was developed to estimate the costs of imrt and 3D-crt in prostate cancer. It included the costs of equipment, staff, and supporting infrastructure. The framework was subsequently adapted to estimate the costs of radiotherapy in breast cancer and head-and-neck cancer. We also tested various scenarios by varying the program maturity and the use of volumetric modulated arc therapy (vmat) alongside imrt. From the perspective of the health care system, treating prostate cancer with imrt and 3D-crt respectively cost $12,834 and $12,453 per patient. The cost of radiotherapy ranged from $5,270 to $14,155 and was sensitive to analytic perspective, radiation technique, and disease site. Cases of head-and-neck cancer were the most costly, being driven by treatment complexity and fractions per treatment. Although imrt was more costly than 3D-crt, its cost will likely decline over time as programs mature and vmat is incorporated. Our costing model can be modified to estimate the costs of 3D-crt and imrt for various disease sites and settings. The results demonstrate the important role of capital costs in studies of radiotherapy cost from a health system perspective, which our model can accommodate. In addition, our study established the need for future analyses of imrt cost to consider how vmat affects time consumption.

Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

International Nuclear Information System (INIS)

Lopez Guerra, Jose L.; Gomez, Daniel R.; Zhuang Yan; Levy, Lawrence B.; Eapen, George; Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing

2012-01-01

Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received ≥60 Gy radio(chemo)therapy for primary NSCLC in 1998–2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient’s preradiation value at the following time intervals: 0–4 (T1), 5–8 (T2), and 9–12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy

Late injury of the eye after conformation radiotherapy for carcinoma of the maxillary sinus

International Nuclear Information System (INIS)

Morita, Kozo

1975-01-01

Late injury of the eye after radiotherapy for 26 patients with carcinoma of the maxillary sinus was discussed. The conformation technique, a kind of improved rotational technique, was used as the method for radiotherapy. The eyes were shielded by a tungsten- or zinc-rod during irradiation. On the healthy-sided eye, which had received a total dose of 1000-1100 rads/6 weeks (max. 1460 rads/6 weeks), no impairment of vision was seen. On the ill-sided eye given a dose of more than 6000 rads/6 weeks, severe panophthalmopathy with corneal ulceration was observed within 1 year after irradiation. Serious deterioration of visual acuity alway occurred 1.5-2 years after on irradiation of the level of 4000 rads/6 weeks. At present the weakening of visual acuity is unlikely to occur after a dose of less than 3000 rads/6 weeks to the lens. From these results it is recommended that the total dose of the eye be reduced to less than 3000 rads/6 weeks. (author)

Evaluation of Sentinel Lymph Node Dose Distribution in 3D Conformal Radiotherapy Techniques in 67 pN0 Breast Cancer Patients.

Science.gov (United States)

Witucki, Gerlo; Degregorio, Nikolaus; Rempen, Andreas; Schwentner, Lukas; Bottke, Dirk; Janni, Wolfgang; Ebner, Florian

2015-01-01

Introduction. The anatomic position of the sentinel lymph node is variable. The purpose of the following study was to assess the dose distribution delivered to the surgically marked sentinel lymph node site by 3D conformal radio therapy technique. Material and Method. We retrospectively analysed 70 radiotherapy (RT) treatment plans of consecutive primary breast cancer patients with a successful, disease-free, sentinel lymph node resection. Results. In our case series the SN clip volume received a mean dose of 40.7 Gy (min 28.8 Gy/max 47.6 Gy). Conclusion. By using surgical clip markers in combination with 3D CT images our data supports the pathway of tumouricidal doses in the SN bed. The target volume should be defined by surgical clip markers and 3D CT images to give accurate dose estimations.

A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain.

Science.gov (United States)

Ranger, A; Dunlop, A; Hutchinson, K; Convery, H; Maclennan, M K; Chantler, H; Twyman, N; Rose, C; McQuaid, D; Amos, R A; Griffin, C; deSouza, N M; Donovan, E; Harris, E; Coles, C E; Kirby, A

2018-06-01

Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs). In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance. One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P FB). Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

International Nuclear Information System (INIS)

Patel, Rakesh R.; Becker, Stewart J.; Das, Rupak K.; Mackie, Thomas R.

2007-01-01

Purpose: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. Methods and Materials: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD mean ) values were compared. Results: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value mean dose of 1.3 Gy 3 and 1.2 Gy 3 , respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. Conclusions: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals

Intensity-modulated radiotherapy vs. parotid-sparing 3D conformal radiotherapy. Effect on outcome and toxicity in locally advanced head and neck cancer

Energy Technology Data Exchange (ETDEWEB)

Lambrecht, M.; Nevens, D.; Nuyts, S. [University Hospitals Leuven (Belgium). Dept. of Radiation Oncology

2013-03-15

Background and purpose: Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of locally advanced head and neck squamous cell carcinoma (HNSCC). In this study, our aim was to retrospectively investigate the effect of the introducing IMRT on outcome and treatment-related toxicity compared to parotid-sparing 3D conformal radiotherapy (3DCRT). Material and methods: A total of 245 patients with stage III and IV HNSCC treated with primary radiotherapy between January 2003 and December 2010 were included in this analysis: 135 patients were treated with 3DCRT, 110 patients with IMRT. Groups were compared for acute and late toxicity, locoregional control (LRC), and overall survival (OS). Oncologic outcomes were estimated using Kaplan-Meier analysis and compared using a log-rank test. Acute toxicity was analyzed according to the Common Terminology Criteria for Adverse Events v3.0 and late toxicity was scored using the RTOG/EORTC late toxicity scoring system. Results: Median follow-up was 35 months in the IMRT group and 68 months in the 3DCRT group. No significant differences were found in 3-year LRC and OS rates between the IMRT group and 3DCRT group. Significantly less acute mucositis {>=} grade 3 was observed in the IMRT group (32% vs. 44%, p = 0.03). There was significantly less late xerostomia {>=} grade 2 in the IMRT group than in the 3DCRT group (23% vs. 68%, p < 0.001). After 24 months, there was less dysphagia {>=} grade 2 in the IMRT group although differences failed to reach statistical significance. Conclusion: The introduction of IMRT in the radiotherapeutic management of locally advanced head and neck cancer significantly improved late toxicity without compromising tumor control compared to a parotid-sparing 3D conformal radiotherapy technique. (orig.)

Dosimetric comparison of three-dimensional conformal and intensity modulated radiotherapy in brain glioma

International Nuclear Information System (INIS)

Lu Jie; Zhang Guifang; Bai Tong; Yin Yong; Fan Tingyong; Wu Chaoxia

2009-01-01

Objective: To investigate the dosimetry advantages of intensity modulated radiotherapy (IMRT)of brain glioma compared with that of three-dimensional conformal radiotherapy (SD CRT). Methods: Ten patients with brain glioma were enrolled in this study. Three-dimensional conf0rmal and intensity modulated radiotherapy plans were performed for each patient. The dose distributions of target volume and normal tissues, conformal index (CI) and heterogeneous index (HI) were analyzed using the dose-volume histogram (DVH). The prescription dose was 60 Gy in 30 fractions. Results: IMRT plans decrease the maximum dose and volume of brainstem, mean dose of affected side parotid and maximum dose of spinal-cord. The CI for PTV of IMRT was superior to that of SD CRT, the HI for PTV has no statistical significance of the two model plans. Conclusions: IMRT plans can obviously decrease the dose and volume of brainstem. IMRT is a potential method in the treatment of brain glioma, and dose escalation was possible in patients with brain glioma. (authors)

Applications of three-dimensional image correlation in conformal radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Van Herk, M; Gilhuijs, K; Kwa, S; Lebesque, J; Muller, S; De Munck, J; Touw, A [Nederlands Kanker Inst. ` Antoni van Leeuwenhoekhuis` , Amsterdam (Netherlands); Kooy, H [Harvard Medical School, Boston, MA (United States)

1995-12-01

The development of techniques for the registration of CT, MRI and SPECT creates new possibilities for improved target volume definition and quantitative image analysis. The discussed technique is based on chamfer matching and is suitable for automatic 3-D matching of CT with CT, CT with MRI, CT with SPECT and MRI with SPECT. By integrating CT with MRI, the diagnostic qualities of MRI are combined with the geometric accuracy of the planning CT. Significant differences in the delineation of the target volume for brain, head and neck and prostate tumors were demonstrated when using integrated CT and MRI compared with using CT alone. In addition, integration of the planning CT with pre-operative scans improves knowledge of possible tumor extents. By first matching scans based on the bony anatomy and subsequently matching on an organ of study, relative motion of the organ is quantified accurately. In a study with 42 CT scans of 11 patients, magnitude and causes of prostate motion were analysed. The most important motion of the prostate is a forward-backward rotation around a point near the apex caused by rectal volume difference. Significant correlations were also found between motion of the legs and the prostate. By integrating functional images made before and after radiotherapy with the planning CT, the relation between local change of lung function and delivered dose has been quantified accurately. The technique of chamfer matching is a convenient and more accurate alternative for the use of external markers in a CT/SPECT lung damage study. Also, damage visible in diagnostic scans can be related to radiation dose, thereby improving follow-up diagnostics. It can be concluded that 3-D image integration plays an important role in assessing and improving the accuracy of radiotherapy and is therefore indispensable for conformal therapy. However, user-friendly implementation of these techniques remains to be done to facilitate clinical application on a large scale.

Applications of three-dimensional image correlation in conformal radiotherapy

International Nuclear Information System (INIS)

Van Herk, M.; Gilhuijs, K.; Kwa, S.; Lebesque, J.; Muller, S.; De Munck, J.; Touw, A.; Kooy, H.

1995-01-01

The development of techniques for the registration of CT, MRI and SPECT creates new possibilities for improved target volume definition and quantitative image analysis. The discussed technique is based on chamfer matching and is suitable for automatic 3-D matching of CT with CT, CT with MRI, CT with SPECT and MRI with SPECT. By integrating CT with MRI, the diagnostic qualities of MRI are combined with the geometric accuracy of the planning CT. Significant differences in the delineation of the target volume for brain, head and neck and prostate tumors have been demonstrated when using integrated CT and MRI compared with using CT alone. In addition, integration of the planning CT with pre-operative scans improves knowledge of possible tumor extents. By first matching scans based on the bony anatomy and subsequently matching on an organ of study, relative motion of the organ is quantified accurately. In a study with 42 CT scans of 11 patients, magnitude and causes of prostate motion have been analysed. The most important motion of the prostate is a forward-backward rotation around a point near the apex caused by rectal volume difference. Significant correlations were also found between motion of the legs and the prostate. By integrating functional images made before and after radiotherapy with the planning CT, the relation between local change of lung function and delivered dose has been quantified accurately. The technique of chamfer matching is a convenient and more accurate alternative for the use of external markers in a CT/SPECT lung damage study. Also, damage visible in diagnostic scans can be related to radiation dose, thereby improving follow-up diagnostics. It can be concluded that 3-D image integration plays an important role in assessing and improving the accuracy of radiotherapy and is therefore indispensable for conformal therapy. However, user-friendly implementation of these techniques remains to be done to facilitate clinical application on a large

Tolerance and early outcome results of postprostatectomy three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Zelefsky, Michael J.; Aschkenasy, Eric; Kelsen, Suzanne; Leibel, Steven A.

1997-01-01

Purpose: Three-dimensional conformal radiotherapy (3D-CRT) has been associated with a reduction in acute and late toxicity among patients treated for localized prostatic cancer. The purpose of this study is to assess the acute and late toxicity of 3D-CRT delivered to patients in the postprostatectomy setting and to analyze which factors predict for durable biochemical control in this group of patients. Methods and Materials: Between 1988 and 1994, 42 patients were treated after prostatectomy with three-dimensional conformal radiotherapy. The median time from prostatectomy to radiotherapy was 11 months. Indications for treatment included a rising serum PSA level in 28 patients (65%) and positive surgical margins without a rising PSA level in 14 (35%). Twenty-five patients (60%) had pathologic stage T3 disease, and 32 (74%) had tumor at or close to the surgical margins. The median dose was 64.8 Gy, and the median follow-up time was 2 years. Results: 3D-CRT in the postprostatectomy setting was well tolerated. Three patients (7%) experienced Grade II acute genitourinary toxicity and nine patients (21%) experienced Grade II acute gastrointestinal toxicity during treatment. No patient experienced Grade III or higher acute morbidity. The 2-year actuarial risk for Grade II late genitourinary and gastrointestinal late complications were 5 and 9%, respectively. In patients with existing incontinence, the incidence of worsening stress incontinence 6 months after treatment was 17%, which resolved within 12 months to its preradiotherapy level in four of six cases (66%). The overall 2-year postirradiation PSA relapse-free survival rate was 53%. The 2-year PSA relapse-free survival was 66% for patients with undetectable PSA levels in the immediate postoperative period compared to 26% for those with detectable levels of PSA after surgery (p 1.0 ng/ml (p 1 ng/ml (p < 0.002) was the most important covariate predicting for a rising PSA after radiotherapy. Conclusions: After

The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

Czech Academy of Sciences Publication Activity Database

Vránová, J.; Vinakurau, S.; Richter, J.; Starec, M.; Fišerová, Anna; Rosina, J.

2011-01-01

Roč. 2, č. 6 (2011), s. 1-13 ISSN 1748-717X R&D Projects: GA AV ČR IAA500200620 Institutional research plan: CEZ:AV0Z50200510 Keywords : 3-dimensional conformal radiotherapy (3DCRT) * gastrointestinal and genitourinary toxicity * prostate cancer Subject RIV: EC - Immunology Impact factor: 2.321, year: 2011

Radiotherapy equipment for conformal radiotherapy and IMRT in the Czech Republic

International Nuclear Information System (INIS)

Horakova, I.; Irena Pavlikova, I.; Novotny, J. ml.

2005-01-01

The development of the equipment of radiotherapy departments in the Czech Republic is presented here. The data from the special questionnaire from 14 workplaces with linear accelerators with multi-leaf collimators (MLC) and electronic portal imaging device (EPID) are included. They show not only the equipment specification but also the application methods, the quality control, plans for future etc. In the Czech Republic, a great extension of modem irradiation techniques and accessories occurs at present. Together with it, it is necessary to develop quality assurance of the whole process of dose delivery to the patient. It is also necessary to assure further education and training of hospital staff. Modern radiotherapy techniques demand sufficient amount of all sources including personal sources. (authors)

Second cancers in children treated with modern radiotherapy techniques

International Nuclear Information System (INIS)

Schneider, Uwe; Lomax, Antony; Timmermann, Beate

2008-01-01

Background and Purpose: The scattered radiation from the treatment volume might be more significant for children than for adults and, as a consequence, modern radiotherapy treatment techniques such as IMRT and passive proton therapy could potentially increase the number of secondary cancers. In this report, secondary cancer risk resulting from new treatment technologies was estimated for an adult prostate patient and a child. Material and methods: The organ equivalent dose (OED) concept with a linear-exponential, a plateau and a linear dose-response curve was applied to dose distributions of an adult prostate patient and a child with a rhabdomyosarcoma of the prostate. Conformal radiotherapy, IMRT with 6 MV photons and proton therapy were planned. OED (cancer risk) was estimated for the whole body, the rectum and the bladder. In addition, relative cumulative risk was calculated. Results: Secondary cancer risk in the adult is not more than 15% it increased when IMRT or passive proton therapy was compared to conventional treatment planning. In the child, risk remains practically constant or was even reduced for proton therapy. The cumulative risk in the child relative to that in the adult can be as large as 10-15. Conclusions: By a comparison between an adult patient and a child treated for a disease of the prostate, it was shown that modern radiotherapy techniques such as IMRT and proton therapy (active and passive) do not increase the risk for secondary cancers

Patient repositioning in prostate conformal radiotherapy by image fusion

International Nuclear Information System (INIS)

Betrouni, Nacim

2004-01-01

This research thesis first proposes an overview of imaging modalities which are generally used in radiotherapy, and briefly presents operation principles for ultrasound scans, scanners and MRI. The issue of patient repositioning in radiotherapy is then introduced, and already proposed solutions are presented. In the next part, the author addresses space location and ultrasound-based location, with a brief overview of methods used to track the displacements of a mobile object, in this case an ultrasound probe, and calibration. Then, after a presentation of the adopted method, and a discussion of published works related to contour extraction and to filtering and noise reduction methods in ultrasound imagery, the author addresses the issue of prostate segmentation based on ultrasound images. The next part deals with image registration with an overview of available methods and tools. A method of registration of pre-operation images obtained by MRI or scanner, and of intra-operation ultrasound images is proposed for a real-time registration. This method is aimed at supporting patient repositioning during prostate conformal radiotherapy

Quality assurance patient positioning and immobilization techniques for radiotherapy

International Nuclear Information System (INIS)

Wadhawan, G.S.; Negi, P.S.; Anand, A.K.; Munjal, R.K.; Sinha, S.N.

2007-01-01

Over the last decade the ability to precisely deliver radiotherapy (RT) treatments has advanced dramatically. Imaging technology has evolved to facilitate better target delineation during treatment planning. Treatment delivery techniques have advanced to enable intensity modulated RT (IMRT) treatments that provide radiation doses, tightly conforming to the target volumes. These advancements have been driven by the dual goals of maximizing the radiation dose to the tumor volume while minimizing the radiation dose to the surrounding normal tissue. The ability to expand the use of these techniques to deliver higher doses in fewer fractions is now largely limited by changes in the tumor position from day to day and even during treatment and so the ability to precisely locate the tumor throughout the course of RT has become a topic of concern

Therapeutic Results of Radiotherapy in Rectal Carcinoma -Comparison of Sandwich Technique Radiotherapy with Postoperative Radiotherapy

International Nuclear Information System (INIS)

Huh, Gil Cha; Suh, Hyun Suk; Lee, Hyuk Sang; Kim, Re Hwe; Kim, Chul Soo; Kim, Hong Yong; Kim, Sung Rok

1996-01-01

Purpose : To evaluate the potential advantage for 'sandwich' technique radiotherapy compared to postoperative radiotherapy in respectable rectal cancer. Between January 1989 and May 1994, 60 patients with respectable rectal cancer were treated at Inje University Seoul and Sanggye Paik Hospital.Fifty one patients were available for analysis : 20 patients were treated with sandwich technique radiotherapy and 31 patients were treated with postoperative radiotherapy. In sandwich technique radiotherapy(RT), patients were treated with preoperative RT 1500 cGy/5fx followed by immediate curative resection. Patients staged as Astler-Coller B2, C were considered for postoperative RT with 2500-4500 cGy. In postoperative RT, total radiation dose of 4500-6120 cGy, 180 cGy daily at 4-6 weeks was delivered. Patients were followed for median period of 25 months. Results : The overall 5-year survival rates for sandwich technique RT group and postoperative RT group were 60% and 71%, respectively(p>0.05). The 5-year disease free survival rates for each group were 63%. There was no difference in local failure rate between two groups(11% versus 7%). Incidence of distant metastasis was 11%(2/20) in the sandwich technique RT group and 20%(6/31) in the postoperative RT group(p>0.05). The frequencies of acute and chronic complications were comparable in both groups. Conclusion : The sandwich technique radiotherapy group shows local recurrence and survival similar to those of postoperative RT alone group but reduced distant metastasis compared to postoperative RT group. But long term follow-up and large number of patients is needed to make an any firm conclusion regarding the value of this sandwich technique RT

A comparative study of standard intensity-modulated radiotherapy and RapidArc planning techniques for ipsilateral and bilateral head and neck irradiation

Energy Technology Data Exchange (ETDEWEB)

Pursley, Jennifer, E-mail: jpursley@mgh.harvard.edu [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Damato, Antonio L.; Czerminska, Maria A.; Margalit, Danielle N. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Sher, David J. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX (United States); Tishler, Roy B. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States)

2017-04-01

The purpose of this study was to investigate class solutions using RapidArc volumetric-modulated arc therapy (VMAT) planning for ipsilateral and bilateral head and neck (H&N) irradiation, and to compare dosimetric results with intensity-modulated radiotherapy (IMRT) plans. A total of 14 patients who received ipsilateral and 10 patients who received bilateral head and neck irradiation were retrospectively replanned with several volumetric-modulated arc therapy techniques. For ipsilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the contralateral parotid, two 260° or 270° arcs, and two 210° arcs. For bilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the shoulders, and 3 arcs. All patients had a sliding-window-delivery intensity-modulated radiotherapy plan that was used as the benchmark for dosimetric comparison. For ipsilateral neck irradiation, a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid was dosimetrically comparable to intensity-modulated radiotherapy, with improved conformity (conformity index = 1.22 vs 1.36, p < 0.04) and lower contralateral parotid mean dose (5.6 vs 6.8 Gy, p < 0.03). For bilateral neck irradiation, 3-arc volumetric-modulated arc therapy techniques were dosimetrically comparable to intensity-modulated radiotherapy while also avoiding irradiation through the shoulders. All volumetric-modulated arc therapy techniques required fewer monitor units than sliding-window intensity-modulated radiotherapy to deliver treatment, with an average reduction of 35% for ipsilateral plans and 67% for bilateral plans. Thus, for ipsilateral head and neck irradiation a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid is

Impact of inter- and intrafraction deviations and residual set-up errors on PTV margins. Different alignment techniques in 3D conformal prostate cancer radiotherapy

International Nuclear Information System (INIS)

Langsenlehner, T.; Doeller, C.; Winkler, P.; Kapp, K.S.; Galle, G.

2013-01-01

The aim of this work was to analyze interfraction and intrafraction deviations and residual set-up errors (RSE) after online repositioning to determine PTV margins for 3 different alignment techniques in prostate cancer radiotherapy. The present prospective study included 44 prostate cancer patients with implanted fiducials treated with three-dimensional (3D) conformal radiotherapy. Daily localization was based on skin marks followed by marker detection using kilovoltage (kV) imaging and subsequent patient repositioning. Additionally, in-treatment megavoltage (MV) images were obtained for each treatment field. In an off-line analysis of 7,273 images, interfraction prostate motion, RSE after marker-based prostate localization, prostate position during each treatment session, and the effect of treatment time on intrafraction deviations were analyzed to evaluate PTV margins. Margins accounting for interfraction deviation, RSE and intrafraction motion were 14.1, 12.9, and 15.1 mm in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) direction for skin mark alignment and 9.6, 8.7, and 2.6 mm for bony structure alignment, respectively. Alignment to implanted markers required margins of 4.6, 2.8, and 2.5 mm. As margins to account for intrafraction motion increased with treatment prolongation PTV margins could be reduced to 3.9, 2.6, and 2.4 mm if treatment time was ≤ 4 min. With daily online correction and repositioning based on implanted fiducials, a significant reduction of PTV margins can be achieved. The use of an optimized workflow with faster treatment techniques such as volumetric modulated arc techniques (VMAT) could allow for a further decrease. (orig.)

Results of three-dimensional conformal radiotherapy and thalidomide for advanced hepatocellular carcinoma

International Nuclear Information System (INIS)

Hsu, Wei-Chung; Chung, Na-Na; Wang, Po-Ming; Ying, Kung-Shih; Shin, Jeng-Shiann; Chao, Che-Jen; Lin, Gau-De; Chan, Sue-Ching; Ting, Lai-Lei

2006-01-01

The purpose of this study was to evaluate the effectiveness of three-dimensional conformal radiotherapy and thalidomide in the treatment of advanced hepatocellular carcinoma. Between 1999 and 2003, 121 patients (mean age, 54.4±12.4 years; range, 20-81 years) with advanced hepatocellular carcinoma received three-dimensional conformal radiotherapy and thalidomide. Radiation was delivered in 1.5 Gy fractions twice daily for 5 days a week, for a total dose of 45-75 Gy. Mean treatment volume was 429.52±408.50 cm 3 (range, 26.89-2284.82 cm 3 ). Thalidomide was given concomitantly: 200 mg/day in 109 patients, 300 mg/day in 8 patients and 400 mg/day in 4 patients. Treatment responses, survival rates and factors affecting survival were analyzed. Treatment responses were observed in 61% of the patients. Liver cirrhosis (P=0.001) and tumor size (P=0.001) significantly affected the tumor responses. Overall survival at 6, 12 and 24 months was 84.8, 60.0 and 44.6%, respectively. On univariate analysis, liver cirrhosis (P=0.003), Karnofsky performance status (P=0.007), tumor size (P<0.001), portal vein tumor thrombosis (P<0.001) and alpha-fetoprotein level (P=0.003) were shown to significantly affect survival. On multivariate analysis, only thrombosis (P=0.039) and alpha-fetoprotein level (P=0.006) were shown to be factors affecting survival. Three-dimensional conformal radiotherapy with thalidomide seems to be effective in the treatment of advanced hepatocellular carcinoma. (author)

Conformal radiotherapy by intensity modulation of pediatrics tumors

International Nuclear Information System (INIS)

Leseur, J.; Le Prise, E.; Carrie, C.; Bernier, V.; Beneyton, V.; Mahe, M.A.; Supiot, S.

2009-01-01

The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)

Parotid gland-sparing 3-dimensional conformal radiotherapy results in less severe dry mouth in nasopharyngeal cancer patients: A dosimetric and clinical comparison with conventional radiotherapy

International Nuclear Information System (INIS)

Jen, Y.-M.; Shih Rompin; Lin, Y.-S.; Su, W.-F.; Ku, C.-H.; Chang, C.-S.; Shueng, P.-W.; Hwang, J.-M.; Liu, D.-W.; Chao, H.-L.; Lin, H.-Y.; Chang, L.-P.; Shum, W.-Y.; Lin, C.-S.

2005-01-01

Background and purpose: This study examined the efficacy of parotid gland sparing of three-dimensional conformal radiotherapy (3DCRT) compared with conventional radiotherapy for NPC patients. Both the dose given to the parotids and clinical assessment of dry mouth were conducted. Materials and methods: Dry mouth was assessed for 108 patients treated with conventional technique and 72 treated with 3DCRT. Dose analysis was performed in 48 patients of the 3DCRT group. A dose of 70 Gy was given to the midplane in conventional radiotherapy and to 90% isodose volume in 3DCRT. Prognostic factors affecting the severity of dry mouth were analyzed using Generalized Estimating Equation (GEE). Results: In the 3DCRT group about 50% of the patients' parotid glands received less than 25 Gy. Parallel analysis of dry mouth shows a significant decrease in the incidence of severe xerostomia after 3DCRT. The proportion of patients without dry mouth was also significantly higher in the 3DCRT group than the conventional group at 1-3 years after completion of radiotherapy. Although 3DCRT delivered a higher dose to the tumor, it spared the parotid gland significantly better than the conventional treatment. Late toxicities were mostly similar between the 2 groups while local control in T4 patients and survival were improved for 3DCRT. Conclusion: Dosimetrically and clinically 3DCRT is better than conventional technique regarding parotid gland protection

Comparison of Heart and Coronary Artery Doses Associated With Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiotherapy for Distal Esophageal Cancer

Energy Technology Data Exchange (ETDEWEB)

Kole, Thomas P.; Aghayere, Osarhieme; Kwah, Jason [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2012-08-01

Purpose: To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Methods and Materials: Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Results: Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Conclusions: Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D

Evaluation of conformal radiotherapy techniques through physics and biologic criteria; Avaliacao de tecnicas radioterapicas conformacionais utilizando criterios fisicos e biologicos

Energy Technology Data Exchange (ETDEWEB)

Bloch, Jonatas Carrero

2012-07-01

In the fight against cancer, different irradiation techniques have been developed based on technological advances and aiming to optimize the elimination of tumor cells with the lowest damage to healthy tissues. The radiotherapy planning goal is to establish irradiation technical parameters in order to achieve the prescribed dose distribution over the treatment volumes. While dose prescription is based on radiosensitivity of the irradiated tissues, the physical calculations on treatment planning take into account dosimetric parameters related to the radiation beam and the physical characteristics of the irradiated tissues. To incorporate tissue's radiosensitivity into radiotherapy planning calculations can help particularize treatments and establish criteria to compare and elect radiation techniques, contributing to the tumor control and the success of the treatment. Accordingly, biological models of cellular response to radiation have to be well established. This work aimed to study the applicability of using biological models in radiotherapy planning calculations to aid evaluating radiotherapy techniques. Tumor control probability (TCP) was studied for two formulations of the linear-quadratic model, with and without repopulation, as a function of planning parameters, as dose per fraction, and of radiobiological parameters, as the α/β ratio. Besides, the usage of biological criteria to compare radiotherapy techniques was tested using a prostate planning simulated with Monte Carlo code PENELOPE. Afterwards, prostate planning for five patients from the Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto, USP, using three different techniques were compared using the tumor control probability. In that order, dose matrices from the XiO treatment planning system were converted to TCP distributions and TCP-volume histograms. The studies performed allow the conclusions that radiobiological parameters can significantly influence tumor control

Conformal three dimensional radiotherapy treatment planning in Lund

International Nuclear Information System (INIS)

Knoos, T.; Nilsson, P.; Anders, A.

1995-01-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam's eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam's eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment

Anal wall sparing effect of an endorectal balloon in 3D conformal and intensity-modulated prostate radiotherapy.

NARCIS (Netherlands)

Smeenk, R.J.; Lin, E.N.J.T. van; Kollenburg, P. van; Kunze-Busch, M.C.; Kaanders, J.H.A.M.

2009-01-01

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

Irradiation of head-and-neck tumors with intensity modulated radiotherapy (IMRT). Comparison between two IMRT techniques with 3D conformal irradiation

International Nuclear Information System (INIS)

Heeger, Jonas

2013-01-01

For 12 patients with inoperable head-neck carcinoma that were treated with 3D conformal irradiation techniques additional irradiation plans using IMRT were developed. It was shown that the IMRT techniques are superior to the 3D conformal technique. The new rapid arc technique is unclear with respect to the critical organs (parotid glands, spinal canal and mandibles) but is significantly advantageous for the other normal tissue with respect to conformity (steeper dose gradients) and thus radiation dose reduction. The resulting lower irradiation time and the reduced radiation exposure being important for the treatment economy and patients' comfort should favor the more planning intensive rapid arc technique.

Dosimetric comparison of intensity modulated radiotherapy techniques and standard wedged tangents for whole breast radiotherapy

International Nuclear Information System (INIS)

Fong, Andrew; Bromley, Regina; Beat, Mardi; Vien, Din; Dineley, Jude; Morgan, Graeme

2009-01-01

Full text: Prior to introducing intensity modulated radiotherapy (IMRT) for whole breast radiotherapy (WBRT) into our department we undertook a comparison of the dose parameters of several IMRT techniques and standard wedged tangents (SWT). Our aim was to improve the dose distribution to the breast and to decrease the dose to organs at risk (OAR): heart, lung and contralateral breast (Contra Br). Treatment plans for 20 women (10 right-sided and 10 left-sided) previously treated with SWT for WBRT were used to compare (a) SWT; (b) electronic compensators IMRT (E-IMRT); (c) tangential beam IMRT (T-IMRT); (d) coplanar multi-field IMRT (CP-IMRT); and (e) non-coplanar multi-field IMRT (NCP-IMRT). Plans for the breast were compared for (i) dose homogeneity (DH); (ii) conformity index (CI); (iii) mean dose; (iv) maximum dose; (v) minimum dose; and dose to OAR were calculated (vi) heart; (vii) lung and (viii) Contra Br. Compared with SWT, all plans except CP-IMRT gave improvement in at least two of the seven parameters evaluated. T-IMRT and NCP-IMRT resulted in significant improvement in all parameters except DH and both gave significant reduction in doses to OAR. As on initial evaluation NCP-IMRT is likely to be too time consuming to introduce on a large scale, T-IMRT is the preferred technique for WBRT for use in our department.

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Oh Nam [Gangneung Asan Hospital, Gangneung (Korea, Republic of); Yang, Oh Nam; Lim, Cheong Hwan [Hanseo Univ., Seosan (Korea, Republic of)

2012-12-15

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

International Nuclear Information System (INIS)

Yang, Oh Nam; Yang, Oh Nam; Lim, Cheong Hwan

2012-01-01

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose

Situation of radiotherapy in 2010 - context and methods, data for 2003/2010, synthesis

International Nuclear Information System (INIS)

2011-03-01

Illustrated by data tables and figures, this report first gives an overview of the status and situation of European and French radiotherapy centres, and of care activity authorizations regarding external radiotherapy. It gives an overview of equipment used for treatments and for treatment preparation and delivery, and of the different treatment techniques (three dimensional conformational, intensity-modulated conformational, stereotactic, whole body radiotherapy, proton-therapy). It comments the activity of radiotherapy centres: patients (age, sessions, and treated pathologies), comments data regarding medical and paramedical personnel involved in radiotherapy, and financial data regarding radiotherapy in 2009

Three-dimensional conformal radiotherapy in the treatment of prostate cancer in Australia and New Zealand: Report on a survey of radiotherapy centres and the proceedings of a consensus workshop

International Nuclear Information System (INIS)

Tai, K.-H.; Duchesne, G.; See, A.; Berry, M.

2004-01-01

There is an increasing use of 3-D conformal radiotherapy (3DCRT) in the radiotherapeutic management of prostate cancer. The Faculty of Radiation Oncology Genito-Urinary Group carried out a survey of Australian and New Zealand radiotherapy centres in the preparation of a consensus workshop. Of the 19 centres that were represented, there were 24 radiation oncologists, 16 radiation therapists and 12 medical physicists. The survey collected demographic information and data on the practices undertaken at those centres when delivering curative radiotherapy in the treatment of prostate cancer. There was much variation in the delivery of treatment in the areas of patient set-up, contouring of target volumes and organs of interest during computer planning, the techniques and the dose constraints used in these techniques, the use of adjuvant androgen deprivation therapy and the quality assurance processes used in monitoring effects of treatment. This variability reflects the range of data in the published literature. Emerging trends of practices were also identified. This is a first report on a multi-disciplinary approach to the development of guidelines in 3DCRT of prostate cancer. Copyright (2004) Blackwell Science Pty Ltd

The situation of radiotherapy in 2011

International Nuclear Information System (INIS)

2012-06-01

Published within the frame of the French 2009-2013 cancer plan, this report proposes an analysis of the situation of radiotherapy in France. More particularly, it analyses the French offer in terms of radiotherapy treatments and the French position in Europe. A second part analyses equipment (accelerators and other equipment) and techniques aimed at radiotherapy treatment preparation and delivery. The following techniques are addressed: three-dimensional conformational, intensity modulation, intracranial and extracranial stereotactic, image-guided, total body irradiation, hadron-therapy, and peri-operative radiotherapy. The last parts analyse the activity of radiotherapy centres in terms of treated patients, of patient age structure, of sessions and preparations, and of treated pathologies, the medical and paramedical personnel in charge of radiotherapy, and financial and cost aspects

Conformal three dimensional radiotherapy treatment planning in Lund

Energy Technology Data Exchange (ETDEWEB)

Knoos, T; Nilsson, P [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A [Lund Univ. (Sweden). Dept. of Oncology

1995-12-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

Comparison of Toxicity Between Intensity-Modulated Radiotherapy and 3-Dimensional Conformal Radiotherapy for Locally Advanced Non-small-cell Lung Cancer.

Science.gov (United States)

Ling, Diane C; Hess, Clayton B; Chen, Allen M; Daly, Megan E

2016-01-01

The role of intensity-modulated radiotherapy (IMRT) in reducing treatment-related toxicity for locally advanced non-small-cell lung cancer (NSCLC) remains incompletely defined. We compared acute toxicity and oncologic outcomes in a large cohort of patients treated with IMRT or 3-dimensional conformal radiotherapy (3-DCRT), with or without elective nodal irradiation (ENI). A single-institution retrospective review was performed evaluating 145 consecutive patients with histologically confirmed stage III NSCLC treated with definitive chemoradiotherapy. Sixty-five (44.8%) were treated with 3-DCRT using ENI, 43 (30.0%) with 3-DCRT using involved-field radiotherapy (IFRT), and 37 (25.5%) with IMRT using IFRT. All patients received concurrent chemotherapy. Comparison of acute toxicities by treatment technique (IMRT vs. 3-DCRT) and extent of nodal irradiation (3-DCRT-IFRT vs. 3-DCRT-ENI) was performed for grade 2 or higher esophagitis or pneumonitis, number of acute hospitalizations, incidence of opioid requirement, percutaneous endoscopic gastrostomy utilization, and percentage weight loss during treatment. Local control and overall survival were analyzed by the Kaplan-Meier method. We identified no significant differences in any measures of acute toxicity by treatment technique or extent of nodal irradiation. There was a trend toward lower rates of grade 2 or higher pneumonitis among IMRT patients compared to 3-DCRT patients (5.4% vs. 23.0%; P = .065). Local control and overall survival were similar between cohorts. Acute and subacute toxicities were similar for patients treated with IMRT and with 3-DCRT with or without ENI, with a nonsignificant trend toward a reduction in pneumonitis with IMRT. Larger studies are needed to better define which patients will benefit from IMRT. Copyright © 2016 Elsevier Inc. All rights reserved.

Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

Energy Technology Data Exchange (ETDEWEB)

Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian [Department of Radiation Oncology, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

2015-09-15

We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D{sub 105%} and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT.

Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

International Nuclear Information System (INIS)

Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian

2015-01-01

We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D 105% and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT

Conformal radiotherapy in the adjuvant treatment of gastric cancer: Review of 82 cases

International Nuclear Information System (INIS)

Kassam, Zahra; Lockwood, Gina; O'Brien, Catherine; Brierley, James; Swallow, Carol; Oza, Amit; Siu, Lillian; Knox, Jennifer J.; Wong, Rebecca; Cummings, Bernard; Kim, John; Moore, Malcolm; Ringash, Jolie

2006-01-01

Background: The Intergroup 0116 study showed a survival benefit with adjuvant chemoradiotherapy (CRT) for resected gastric cancer. We report our experience using conformal radiotherapy (RT). Methods and Materials: Eighty-two patients with resected gastric or gastroesophageal junction (GEJ) adenocarcinoma, Stage IB to IV (M0), were treated with 45 Gy in 25 fractions using a 5-field conformal technique. Chemotherapy was in accordance with the Intergroup 0116 study, or infusional 5-fluorouracil and cisplatin in a phase I/II trial. Results: Mean age was 56.4 years. Median follow-up was 22.8 months. Grade 3 or greater acute toxicity (National Cancer Institute Common Terminology Criteria of Adverse Events, version 3.0) was noted in 57% of patients (upper gastrointestinal tract 34%, hematologic 33%). One patient died of neutropenic sepsis. Radiation Therapy Oncology Group Grade 3 late toxicity included esophageal strictures (3 patients) and small bowel obstruction (1 patient). Full course CRT was completed by 67% of patients. Of 26 patients who relapsed, 20 died. Site of first relapse was available on 23 patients: 8 locoregional and distant, 4 locoregional alone, 11 distant alone. Overall and relapse-free survival were 69% and 54% at 3 years. Conclusion: Adjuvant CRT for gastric cancer, even with conformal RT, is associated with significant toxicity. Survival was comparable to that reported in the Intergroup 0116 study

Phase I study of conformal radiotherapy with concurrent gemcitabine in locally advanced bladder cancer

International Nuclear Information System (INIS)

Sangar, Vijay K.; McBain, Catherine A.; Lyons, Jeanette; Ramani, Vijay; Logue, John; Wylie, James; Clarke, Noel W.; Cowan, Richard A.

2005-01-01

Purpose: A prospective phase I trial was conducted to determine the maximal tolerated dose of gemcitabine given once weekly during hypofractionated conformal radiotherapy to patients with locally advanced transitional cell carcinoma of the bladder. Eight male patients, median age 69 years, with Stage T2 (n = 4) or T3 (n = 4) N0M0, were enrolled in cohorts of 3. Treatment comprised conformal radiotherapy (52.5 Gy in 20 fractions) within 4 weeks, with concurrent gemcitabine once weekly for four cycles. The weekly gemcitabine dose was escalated from 100 mg/m 2 in increments of 50 mg/m 2 per cohort. Dose-limiting toxicity was defined as any acute Radiation Therapy Oncology Group (RTOG) toxicity Grade 3 or greater arising in >1 of 3 patients in each cohort. Tumor response was assessed cystoscopically and radiologically at 3 months. Results: All 8 patients completed radiotherapy, and 6 of 8 completed chemoradiotherapy. No acute toxicity greater than RTOG Grade 1 was seen with gemcitabine at 100 mg/m 2 . Dose-limiting toxicity was observed at 150 mg/m 2 with Grade 3 toxicity seen in 2 of 2 patients (one bladder, one bowel). An additional 3 patients received 100 mg/m 2 with minimal toxicity. No hematologic toxicity was encountered. A complete response was seen in 7 (87.5%) of 8 patients, all of whom were disease free at a median follow-up of 19.5 months (range, 14-23 months). No late toxicity (greater than RTOG Grade 0) has been observed. Conclusion: The maximal tolerated dose for gemcitabine given once weekly with concurrent hypofractionated conformal bladder radiotherapy was 150 mg/m 2 , with a maximal recommended dose of 100 mg/m 2 . This dose regimen has now entered Phase II clinical trials

Development of model plans in three dimensional conformal radiotherapy for brain tumors

International Nuclear Information System (INIS)

Pyo, Hongryull; Kim, Gwieon; Keum, Kichang; Chang, Sekyung; Suh, Changok; Lee, Sanghoon

2002-01-01

Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plans for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decided. Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal tumor-5.7 x 8.2 x 7.6 cm, suprasellar tumor-3 x 4 x 4.1 cm, thalamic tumor-3.1 x 5.9 x 3.7 cm, frontoparietal tumor-5.5 x 7 x 5.5 cm, and occipitoparietal tumor-5 x 5.5 x 5 cm. Plans using parallel opposed 2-portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D plans: 27%, 8% → 3D plans: 1%, 1%). Various dose statistic values did not show any

Computer controlled multi-leaf conformation radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Matsuda, T [Tokyo Metropolitan Komagome Hospital (Japan); Inamura, K

1981-10-01

A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer.

Computer controlled multi-leaf conformation radiotherapy

International Nuclear Information System (INIS)

Matsuda, Tadayoshi; Inamura, Kiyonari.

1981-01-01

A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer. (author)

Three dimensional conformal radiotherapy for synchronous bilateral breast irradiation using a mono iso-center technique

Science.gov (United States)

Mani, Karthick Raj; Basu, Saumen; Bhuiyan, Md Anisuzzaman; Ahmed, Sharif; Sumon, Mostafa Aziz; Haque, Kh Anamul; Sengupta, Ashim Kumar; Un Nabi, Md Rashid; Das, K. J. Maria

2017-06-01

Objective: The purpose of this study is to demonstrate the synchronous bilateral breast irradiation radiotherapy technique using a single isocenter. Materials and Methods: Six patients of synchronous bilateral breast were treated with single isocenter technique from February 2011 to June 2016. All the patients underwent a CT-simulation using appropriate positioning device. Target volumes and critical structures like heart, lung, esophagus, thyroid, etc., were delineated slice by slice in the CT data. An isocenter was placed above the sternum on the skin and both medial tangential and lateral tangential of the breast / chest wall were created using asymmetrical jaws to avoid the beam divergence through the lung and heart. The field weighting were adjusted manually to obtain a homogenous dose distribution. The planning objectives were to deliver uniform doses around the target and keep the doses to the organ at risk within the permissible limit. The beam energy of 6 MV or combination of 6 MV and 15 MV photons were used in the tangential fields according to the tangential separation. Boluses were used for all the mastectomy patients to increase the doses on the chest wall. In addition to that enhanced dynamic wedge and field in field technique were also used to obtain a homogenous distribution around the target volume and reduce the hot spots. The isocenter was just kept on the skin, such that the beam junctions will be overlapped only on the air just above the sternum. Acute toxicity during the treatment and late toxicity were recorded during the patient's follow-up. Results: During the radiotherapy treatment follow-up there were no acute skin reactions in the field junctions, but one patient had grade 1 esophagitis and two patients had grade 2 skin reactions in the chest wall. With a median follow-up of 38.5 months (range: 8 - 49 months), no patients had a local recurrence, but one patients with triple negative disease had a distant metastases in brain and died

Open table-top device positioning technique to reduce small bowel obstruction. Positioning accuracy and impact on conformal radiation therapy techniques

International Nuclear Information System (INIS)

Rudat, V.; Flentje, M.; Engenhart, R.; Metzger, M.; Wannenmacher, M.

1995-01-01

The immobilization error of patients positioned on the opern table-top device in prone prosition as well as the movement of the small bowel out of the pelvis by this positioning technique was determined. The positioning error is of special importance for the 3-dimensional treatment planning for conformal radiotherapy. The positioning error was determined by superposing 106 portal films with the corresponding simultor films from 21 patients with carcinoma of the rectum who received 3D-planned conformal radiotherapy (o-field technique with irregular blocks). The movement of the small bowel out of the pelvis was studied by comparing simulator films after barium swallow in supine and open table-top position as well with 3D-treatment plans of the same patient in both positions in 3 cases. The positioning error along the medio-lateral, dorso-ventral und cranio-caudal axis was 1.4/-0.6/1.8 mm and the standard deviation 4.4/6.8/6.3 mm, respectively. In comparison to the supine position more rotation errors in the sagittal view were observed (37% and 9% respectively) with a media of 5.1 . Six out of 22 patients showed no adhesions of the small bowel and a complete movement out of the tratment field was achieved. 14 out of 16 Patients with adhesions revealed a partial movement of the small bowel out of the treatment field. Comparing 3D-treatment plans in both positions again demonstrated a marked reduction of the irradiated small bowel volume with the use of the open table-top decive. (orig.) [de

Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

International Nuclear Information System (INIS)

Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

1999-01-01

Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

An easy irradiation technique (partial half-beam) to reduce renal dose in radiotherapy of cervical cancer including paraaortic lymph nodes

International Nuclear Information System (INIS)

Vorwerk, H.; Wagner, D.; Christiansen, H.; Hess, C.F.; Hermann, R.M.

2008-01-01

Purpose: for radiation treatment of patients with cervical cancer and a high risk for paraaortic lymph node involvement, an easy three-dimensional (3-D) conformal irradiation technique (partial half-beam [PHB]) for protection of organs at risk, especially of renal tissue, was developed. Patients and methods: in five consecutive female patients a computed tomography scan was performed. Dose-volume histograms of the renal tissue and other organs at risk were analyzed for PHB, three other 3-D conformal techniques, and an intensity-modulated radiotherapy (IMRT) technique. Results: the PHB technique reduced the renal volume and volumes of other organs at risk exposed to radiation doses when comparing all patients to the other 3-D conformal techniques. With use of the IMRT technique more renal tissue volume received very low radiation doses (≤ 6.8 Gy) whereas the D 10 was lower than with the PHB technique. Conclusion: in female patients with cervical cancer and high risk for paraaortic lymph node involvement, the use of the PHB technique is recommended to reduce renal radiation exposure, if no IMRT technique should be applied. The PHB technique is very easily and fast applicable. (orig.)

3D-Conformal Versus Intensity-Modulated Postoperative Radiotherapy of Vaginal Vault: A Dosimetric Comparison

International Nuclear Information System (INIS)

Cilla, Savino; Macchia, Gabriella; Digesu, Cinzia; Deodato, Francesco; Romanella, Michele; Ferrandina, Gabriella; Padula, Gilbert; Picardi, Vincenzo; Scambia, Giovanni; Piermattei, Angelo; Morganti, Alessio Giuseppe

2010-01-01

We evaluated a step-and-shoot IMRT plan in the postoperative irradiation of the vaginal vault compared with equispaced beam arrangements (3-5) 3D-radiotherapy (RT) optimized plans. Twelve patients were included in this analysis. Four plans for each patient were compared in terms of dose-volume histograms, homogeneity index (HI), and conformity index (CI): (1) 3 equispaced beam arrangement 3D-RT; (2) 4 equispaced beam arrangement 3D-RT; (3) 5 equispaced beam arrangement 3D-RT; (4) step-and-shoot IMRT technique. CI showed a good discrimination between the four plans. The mean scores of CI were 0.58 (range: 0.38-0.67) for the 3F-CRT plan, 0.58 (range: 0.41-0.66) for 4F-CRT, 0.62 (range: 0.43-0.68) for 5F-CRT and 0.69 (range: 0.58-0.78) for the IMRT plan. A significant improvement of the conformity was reached by the IMRT plan (p mean , V90%, V95%, V100% was recorded for rectal and bladder irradiation with the IMRT plan. Surprisingly, IMRT supplied a significant dose reduction also for rectum and bladder V30% and V50%. A significant dosimetric advantage of IMRT over 3D-RT in the adjuvant treatment of vaginal vault alone in terms of treatment conformity and rectum and bladder sparing is shown.

Prone Hypofractionated Whole-Breast Radiotherapy Without a Boost to the Tumor Bed: Comparable Toxicity of IMRT Versus a 3D Conformal Technique

Energy Technology Data Exchange (ETDEWEB)

Hardee, Matthew E.; Raza, Shahzad; Becker, Stewart J.; Jozsef, Gabor; Lymberis, Stella C. [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States); Hochman, Tsivia; Goldberg, Judith D. [Division of Biostatistics, New York University School of Medicine, New York, NY (United States); DeWyngaert, Keith J. [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States)

2012-03-01

Purpose: We report a comparison of the dosimetry and toxicity of three-dimensional conformal radiotherapy (3D-CRT) vs. intensity-modulated radiotherapy (IMRT) among patients treated in the prone position with the same fractionation and target of the hypofractionation arm of the Canadian/Whelan trial. Methods and Materials: An institutional review board-approved protocol identified a consecutive series of early-stage breast cancer patients treated according to the Canadian hypofractionation regimen but in the prone position. Patients underwent IMRT treatment planning and treatment if the insurance carrier approved reimbursement for IMRT; in case of refusal, a 3D-CRT plan was used. A comparison of the dosimetric and toxicity outcomes during the acute, subacute, and long-term follow-up of the two treatment groups is reported. Results: We included 97 consecutive patients with 100 treatment plans in this study (3 patients with bilateral breast cancer); 40 patients were treated with 3D-CRT and 57 with IMRT. IMRT significantly reduced the maximum dose (Dmax median, 109.96% for 3D-CRT vs. 107.28% for IMRT; p < 0.0001, Wilcoxon test) and improved median dose homogeneity (median, 1.15 for 3D-CRT vs. 1.05 for IMRT; p < 0.0001, Wilcoxon test) when compared with 3D-CRT. Acute toxicity consisted primarily of Grade 1 to 2 dermatitis and occurred in 92% of patients. Grade 2 dermatitis occurred in 13% of patients in the 3D-CRT group and 2% in the IMRT group. IMRT moderately decreased rates of acute pruritus (p = 0.03, chi-square test) and Grade 2 to 3 subacute hyperpigmentation (p = 0.01, Fisher exact test). With a minimum of 6 months' follow-up, the treatment was similarly well tolerated in either group, including among women with large breast volumes. Conclusion: Hypofractionated breast radiotherapy is well tolerated when treating patients in the prone position, even among those with large breast volumes. Breast IMRT significantly improves dosimetry but yields only a modest

Minimising contralateral breast dose in post-mastectomy intensity-modulated radiotherapy by incorporating conformal electron irradiation

NARCIS (Netherlands)

van der Laan, Hans Paul; Korevaar, Erik W; Dolsma, Willemtje; Maduro, John H; Langendijk, Johannes A

PURPOSE: To assess the potential benefit of incorporating conformal electron irradiation in intensity-modulated radiotherapy (IMRT) for loco-regional post-mastectomy RT. PATIENTS AND METHODS: Ten consecutive patients that underwent left-sided mastectomy were selected for this comparative planning

The comparison of 5-field conformal radiotherapy techniques for the treatment of prostate cancer: The best for femoral head sparing

International Nuclear Information System (INIS)

Zare, Mahkameh; Lashkari, Marzieh; Ghalehtaki, Reza; Ghasemi, Arash; Dehghan Manshadi, Hamidreza; Mir, Ali; Noorollahi, Somayeh; Alamolhoda, Mahboobeh

2016-01-01

External radiotherapy is a standard treatment procedure for localized prostate cancer. Given the relatively high long term survival treatment complications have been brought in center of attention. In this planning study, between 2012 and 2014, CT simulation data of 90 consecutive high-risk prostate cancer patients were collected. In the first phase, all were planned for whole pelvis irradiation up to 46Gy in 23 daily fractions. In the second phase, only the prostate gland was the target of radiation. Next, the subjects were divided randomly into three groups and each received a unique 5field conformal radiation plan including Plan A (Gantry angle: 0, 60, 120, 240, and 300), Plan B (Gantry angles: 0, 90, 120, 240, and 270) and Plan C (Gantry angles: 0, 60, 90, 270, and 300). The total dose was 70Gy. For each patient, the rectum, bladder, and both femoral heads were contoured as the at risk organs (OAR). From dose volume histograms, the proportional dose of PTV V100, the bladder and rectum V80 and V90 and femoral head V50 and V100 were calculated in all subjects and compared across plans. A statistically significant difference in the femoral head V50 and V100 was found between our studied 5field plans so that in Plan A (beam angles: 0, 60, 120, 240 and 300) less dose was received by both heads of femur. This study suggests that 5 field treatment planning including an anterior, two anterior oblique and two posterior oblique portals to be more proper for 3D conformal radiotherapy in order to spare femoral head with acceptable PTV coverage, and bladder and rectal doses.

Assessment of improved organ at risk sparing for advanced cervix carcinoma utilizing precision radiotherapy techniques

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Georg, D.; Georg, P.; Hillbrand, M.; Poetter, R.; Mock, U. [Dept. of Radiotherapy, Medical Univ. AKH, Vienna (Austria)

2008-11-15

Purpose: to evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer. Patients and methods: in five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and proton therapy (IMPT) as well as proton beam therapy (PT) based on passive scattering. Planning target volumes (PTVs) included primary tumor and pelvic and para-aortic lymph nodes. Dose-volume histograms (DVHs) were analyzed for the PTV and various organs at risk (OARs) (rectal wall, bladder, small bowel, colon, femoral heads, and kidneys). In addition dose conformity, dose inhomogeneity and overall volumes of 50% isodoses were assessed. Results: all plans were comparable concerning PTV parameters. Large differences between photon and proton techniques were seen in volumes of the 50% isodoses and conformity indices. DVH for colon and small bowel were significantly improved with PT and IMPT compared to IMXT, with D{sub mean} reductions of 50-80%. Doses to kidneys and femoral heads could also be substantially reduced with PT and IMPT. Sparing of rectum and bladder was superior with protons as well but less pronounced. Conclusion: proton beam RT has significant potential to improve treatment related side effects in the bowel compared to photon beam RT in patients with advanced cervix carcinoma. (orig.)

Assessment of improved organ at risk sparing for advanced cervix carcinoma utilizing precision radiotherapy techniques

International Nuclear Information System (INIS)

Georg, D.; Georg, P.; Hillbrand, M.; Poetter, R.; Mock, U.

2008-01-01

Purpose: to evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer. Patients and methods: in five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and proton therapy (IMPT) as well as proton beam therapy (PT) based on passive scattering. Planning target volumes (PTVs) included primary tumor and pelvic and para-aortic lymph nodes. Dose-volume histograms (DVHs) were analyzed for the PTV and various organs at risk (OARs) (rectal wall, bladder, small bowel, colon, femoral heads, and kidneys). In addition dose conformity, dose inhomogeneity and overall volumes of 50% isodoses were assessed. Results: all plans were comparable concerning PTV parameters. Large differences between photon and proton techniques were seen in volumes of the 50% isodoses and conformity indices. DVH for colon and small bowel were significantly improved with PT and IMPT compared to IMXT, with D mean reductions of 50-80%. Doses to kidneys and femoral heads could also be substantially reduced with PT and IMPT. Sparing of rectum and bladder was superior with protons as well but less pronounced. Conclusion: proton beam RT has significant potential to improve treatment related side effects in the bowel compared to photon beam RT in patients with advanced cervix carcinoma. (orig.)

Radiotherapy for Adult Medulloblastoma: Evaluation of Helical Tomotherapy, Volumetric Intensity Modulated Arc Therapy, and Three-Dimensional Conformal Radiotherapy and the Results of Helical Tomotherapy Therapy

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Sun Zong-wen

2018-01-01

Full Text Available Introduction. All adult medulloblastoma (AMB patients should be treated with craniospinal irradiation (CSI postoperatively. Because of the long irradiation range, multiple radiation fields must be designed for conventional radiotherapy technology. CSI can be completed in only one session with helical tomotherapy (HT. We evaluated the dose of HT, volumetric intensity modulated arc therapy (VMAT, and three-dimensional conformal radiotherapy (3D-CRT of AMB and the results of 5 cases of AMB treated with HT. Methods. Complete craniospinal and posterior cranial fossa irradiation with HT, VMAT, and 3D-CRT and dose evaluation were performed. And results of 5 cases of AMB treated with HT were evaluated. Results. A large volume of tissue was exposed to low dose radiation in the organs at risk (OAR, while a small volume was exposed to high dose radiation with HT. The conformity and uniformity of the targets were good with HT and VMAT, and the volume of targets exposed to high dose with VMAT was larger than that of HT. The uniformity of 3D-CRT was also good, but the dose conformity was poor. The main toxicity was hematologic toxicity, without 4th-degree bone marrow suppression. There was 3rd-degree inhibition in the white blood cells, hemoglobin, and platelets. The three female patients suffered menstrual disorders during the course of radiation. Two female patients with heavy menstruation suffered 3rd-degree anemia inhibition, and 2 patients suffered amenorrhea after radiotherapy. Although menstrual cycle was normal, the third patient was not pregnant. Conclusion. CSI with HT is convenient for clinical practice, and the side effects are mild. With good conformity and uniformity, VMAT can also be used for selection in CSI. For poor conformity, 3D-CRT should not be the priority selection for CSI. In female patients, the ovaries should be protected.

Conformal fields in prostate radiotherapy: A comparison between measurement, calculation and simulation

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Seied R Mahdavi

2012-01-01

Full Text Available Aims: The objective of this study is to evaluate the accuracy of a treatment planning system (TPS for calculating the dose distribution parameters in conformal fields (CF. Dosimetric parameters of CF′s were compared between measurement, Monte Carlo simulation (MCNP4C and TPS calculation. Materials and Methods: Field analyzer water phantom was used for obtaining percentage depth dose (PDD curves and beam profiles (BP of different conformal fields. MCNP4C was used to model conformal fields dose specification factors and head of linear accelerator varian model 2100C/D. Results: Results showed that the distance to agreement (DTA and dose difference (DD of our findings were well within the acceptance criteria of 3 mm and 3%, respectively. Conclusions: According to this study it can be revealed that TPS using equivalent tissue air ratio calculation method is still convenient for dose prediction in non small conformal fields normally used in prostate radiotherapy. It was also showed that, since there is a close correlation with Monte Carlo simulation, measurements and TPS, Monte Carlo can be further confirmed for implementation and calculation dose distribution in non standard and complex conformal irradiation field for treatment planning systems.

Dosimetric Comparison of Three Dimensional Conformal Radiation Radiotherapy and Helical Tomotherapy Partial Breast Cancer

International Nuclear Information System (INIS)

Kim, Dae Woong; Kim, Jong Won; Choi, Yun Kyeong; Kim, Jung Soo; Hwang, Jae Woong; Jeong, Kyeong Sik; Choi, Gye Suk

2008-01-01

The goal of radiation treatment is to deliver a prescribed radiation dose to the target volume accurately while minimizing dose to normal tissues. In this paper, we comparing the dose distribution between three dimensional conformal radiation radiotherapy (3D-CRT) and helical tomotherapy (TOMO) plan for partial breast cancer. Twenty patients were included in the study, and plans for two techniques were developed for each patient (left breast:10 patients, right breast:10 patients). For each patient 3D-CRT planning was using pinnacle planning system, inverse plan was made using Tomotherapy Hi-Art system and using the same targets and optimization goals. We comparing the Homogeneity index (HI), Conformity index (CI) and sparing of the organs at risk for dose-volume histogram. Whereas the HI, CI of TOMO was significantly better than the other, 3D-CRT was observed to have significantly poorer HI, CI. The percentage ipsilateral non-PTV breast volume that was delivered 50% of the prescribed dose was 3D-CRT (mean: 40.4%), TOMO (mean: 18.3%). The average ipsilateral lung volume percentage receiving 20% of the PD was 3D-CRT (mean: 4.8%), TOMO (mean: 14.2), concerning the average heart volume receiving 20% and 10% of the PD during treatment of left breast cancer 3D-CRT (mean: 1.6%, 3.0%), TOMO (mean: 9.7%, 26.3%) In summary, 3D-CRT and TOMO techniques were found to have acceptable PTV coverage in our study. However, in TOMO, high conformity to the PTV and effective breast tissue sparing was achieved at the expense of considerable dose exposure to the lung and heart.

Hyperfractionated conformal radiotherapy in locally advanced prostate cancer: results of a dose escalation study

International Nuclear Information System (INIS)

Forman, Jeffrey D.; Duclos, Marie; Shamsa, Falah; Porter, Arthur T.; Orton, Colin

1996-01-01

Purpose: This study was initiated to assess the incidence of chronic complications and histologic and biochemical control following hyperfractionated conformal radiotherapy in patients with locally advanced prostate cancer. Methods and Materials: Between October 1991 and October 1994, 49 patients with locally advanced prostate cancer were entered on the first two dose levels of a prospective dose-escalation study using hyperfractionated three dimensional conformal radiotherapy. The first 25 patients received a minimum tumor dose of 78 Gy to the prostate and seminal vesicles in 6 weeks at 1.3 Gy, b.i.d. No increase in chronic toxicity compared with conventional radiotherapy was noted; therefore, an additional 24 patients were treated to a minimum tumor dose of 82.8 Gy to the prostate and seminal vesicles in 7 weeks at 1.15 Gy, b.i.d. Toxicity was scored according to the Radiation Therapy Oncology Group morbidity grading scale. Efficacy was assessed through scheduled postradiation prostate specific antigen values and ultrasound-guided biopsies. The median follow-up for the entire group was 20 months. Results: The hyperfractionated external radiation was well tolerated with minimal acute morbidity. At 30 months, the actuarial probability of Grade 2 gastrointestinal toxicity was 17%. At 30 months, the actuarial probability of Grade 2 genitourinary toxicity was 16%. There was no statistically significant difference between the two dose levels. No Grade 3 or 4 gastrointestinal or genitourinary toxicity was noted. At 12 months, 84% of patients had a prostate specific antigen ≤ 4; and 53%; ≤ 1 ng/ml. At 12 months, 71% of patients had post radiation biopsies that were either negative (55%) or showed a marked therapeutic effect (16%). Conclusion: The use of hyperfractionated conformal radiotherapy facilitated dose escalation with no increase in chronic toxicity compared to standard doses. The initial tumor response based on prostate specific antigen measurements and

Effects of three-dimensional conformal radiotherapy, indensity modulated radiotherapy, and conventional radiotherapy ON treatment of esophageal cancer

Directory of Open Access Journals (Sweden)

Jian-Jun Han

2016-07-01

Full Text Available Objective: To compare the irradiation volume, short-term and long-term efficacy of conventional radiotherapy (CR, three-dimensional conformal radiotherapy (3D-CRT, and indensity modulated radiotherapy (IMRT in the treatment of esophageal cancer. Methods: A retrospective analysis method was adopted. The patients were divided into CR group (n=42, 3D-CRT group (n=45, and IMRT group (n=40. A follow-up visit was paid to collect the short-term and long-term efficacy, and the occurrence of adverse reactions. The gross tumor voluem (GTV, clinical target volume (CTV, planning target volume (PTV, and irradiation volume of organs (bilateral lungs, spinal cord, and heart at risk (OAR in the three groups were compared. Results: It was found by target volume comparison that the mean values of GTV, CTV, and PTV in the three groups were significantly increased (P0.05. The occurrence rate of adverse reactions in 3D-CRT group and IMRT group was significantly lower than that in CR group (P0.05. The difference of 1-year survival rate among the three groups was not statistically significant (P=0.144, but 3-year and 5-year survival rates in 3D-CRT group and IMRT group were significantly higher than those in CR group (P<0.05. Conclusions: 3D-CRT and IMRT can significantly enhance the short-term and long-term efficacy for esophageal cancer patients, and alleviate the radioactive damage; therefore, they are deserved to be widely recommended in the clinic.

Treatment planning evaluation of non-coplanar techniques for conformal radiotherapy of the prostate

International Nuclear Information System (INIS)

Bedford, James L.; Henrys, Anthony J.; Dearnaley, David P.; Khoo, Vincent S.

2005-01-01

Background and purpose: To evaluate the benefit of using non-coplanar treatment plans for irradiation of two different clinical treatment volumes: prostate only (PO) and the prostate plus seminal vesicles (PSV). Material and methods: An inverse planning algorithm was used to produce three-field, four-field, five-field and six-field non-coplanar treatment plans without intensity-modulation in ten patients. These were compared against a three-field coplanar plan. A dose of 74 Gy was prescribed to the isocentre. Plans were compared using the minimum dose to the planning target volume (PTV), maximum dose to the small bowel, and irradiated volumes of rectum, bladder and femoral head. Biological indices were also evaluated. Results: For the PO group, volume of rectum irradiated to 60 Gy (V 60 ) was 22.5±3.7% for the coplanar plan, and 21.5±5.3% for the five-field non-coplanar plan, which was the most beneficial (p=0.3). For the PSV group, the five-field non-coplanar plan was again the most beneficial. Rectal V 60 was in this case reduced from 41.5±10.4% for the coplanar plan to 35.2±9.3% for the non-coplanar plan (p=0.02). Conclusions: The use of non-coplanar beams in conformal prostate radiotherapy provides a small increase in rectal sparing, more significantly with PSV volumes than for PO volumes

Hypofractionated three-dimensional conformal radiotherapy for medically inoperable early stage

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Lee, Joo Ho; Wu, Hong Gyun; KIm, Hak Jae; Park, Charn Il; Lee, Se Hoon; Kim, Dong Wan; Heo, Dae Seong [Seoul National University College of Medicine, Seou (Korea, Republic of)

2013-01-15

The purpose of this study was to assess the clinical outcomes of hypofractionated radiotherapy (HFRT) with three-dimensional conformal technique for medically inoperable patients with early stage non-small-cell lung cancer (NSCLC) and to evaluate prognostic factors. We performed a retrospective review of 26 patients who underwent HFRT for early stage NSCLC between September 2005 and August 2011. Only clinical stage T1-3N0 was included. The median RT dose was 70 Gy (range, 60 to 72 Gy) and the median biologically equivalent dose (BED) was 94.5 Gy (range, 78.0 to 100.8 Gy). In 84.6% of patients, 4 Gy per fraction was used. Neoadjuvant chemotherapy with paclitaxel and cisplatin was given to 2 of 26 patients. The median follow-up time for surviving patients was 21 months (range, 13 to 49 months). The overall response rate was 53.9%, and the initial local control rate was 100%. The median survival duration was 27.8 months. Rates of 2-year overall survival, progression-free survival (PFS), local control (LC), and locoregional-free survival (LRFS) were 54.3%, 61.1%, 74.6%, and 61.9%, respectively. Multivariate analysis showed that BED (>90 vs. {<=}90 Gy) was an independent prognostic factor influencing PFS, LC, and LRFS. Severe toxicities over grade 3 were not observed. Radical HFRT can yield satisfactory disease control with acceptable rates of toxicities in medically inoperable patients with early stage NSCLC. HFRT is a viable alternative for clinics and patients ineligible for stereotactic ablative radiotherapy. BED over 90 Gy and 4 Gy per fraction might be appropriate for HFRT.

A computer-controlled high resolution micro-multi-leaf collimator for stereotactic conformal radio-therapy

International Nuclear Information System (INIS)

Schlegel, Wolfgang; Pastyr, Otto; Kubesch, Rudolf; Diemer, Torsten; Kuester, Gunnilla; Rhein, Bernhard; Hoever, Karl-Heinz

1997-01-01

Purpose/Objective In stereotactic conformal radiotherapy of irregularly shaped lesions, either multi-isocentric convergent beam treatment techniques with circular collimators or irregular shaped beams are being used. While the treatment technique with multiple isocenters has the disadvantage of producing inhomogeneous dose distributions, the use of irregular shaped fields is not yet satisfying from a technical point of view: Cerrobend blocking or the use of static micro MLCs need a long preparation time and only allow static treatment techniques, MLC collimators which are commercially available in connection with modern LINACs have leaf-thickness of at least 1 cm which is too coarse for stereotactic radiotherapy of lesions in the brain and head and neck area. For this reason, we developed a computer controlled micro-MLC with technical specifications matched to the needs of stereotactic radiotherapy and radiosurgery. Materials and Methods The mechanical specifications of the computer controlled micro-MLC were derived from our experience with stereotactic treatment techniques, from the requirement that the MLC has to be attachable as an external device to the accessory holders of standard LINACs, including cost considerations, dosimetric measurements as well as Monte Carlo calculations. The Micro-MLC is controlled by an electronic equipment consisting of a standard PC under Windows 95, an interface board, 14 Micro-controller boards, a verification system and 80 driving units equipped with DC motors and potentiometers. The control program has calibrating, operating, visualizing and test options. Irregular field data are transferred from the treatment planning computer to the control PC and distributed to the micro-controllers, which in parallel are driving three leaves each. Beside the special control unit, we are currently investigating whether the electronics of commercially available integrated large field MLCs can also be used for operating the Micro-MLC. Results

Brainstem tolerance to conformal radiotherapy of skull base tumors

International Nuclear Information System (INIS)

Debus, J.; Hug, E.B.; Liebsch, N.J.; O'Farrel, D.; Finkelstein, D.; Efird, J.; Munzenrider, J.E.

1997-01-01

Purpose: The aim of this study was to analyze the long-term incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy. Methods and Materials: Between 1974 and 1995, 367 patients with chordomas (n = 195) and chondrosarcomas (n = 172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. Following 3D treatment planning with delineation of target volumes and critical nontarget structures dose distributions and dose-volume histograms were calculated. Radiotherapy was given an 1.8 Gy or CGE (=Cobalt Gray Equivalent) dose per fraction, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to ≤64 CGE and to the brainstem center to ≤53 CGE. Results: Follow-up time ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem toxicity was observed in 17 of 367 patients attributable to treatment, resulting in death of three patients. Actuarial rates of 5 and 10-year high-grade toxicity-free survival were 94 and 88%, respectively. Increased risk of brainstem toxicity was significantly associated with maximum dose to brainstem, volume of brainstem receiving ≥50 CGE, ≥55 CGE, and ≥60 CGE, number of surgical procedures, and prevalence of diabetes or high blood pressure. Multivariate analysis identified three independent factors as important prognosticators: number of surgical procedures (p < 0.001), volume of the brainstem receiving 60 CGE (p < 0.001), and prevalence of diabetes (p < 0.01). Conclusions: Tolerance of brainstem to fractionated radiotherapy appears to be a steep function of tissue volume included in high dose regions rather than the maximum dose of brainstem alone. In addition, presence of predisposing factors as well as extent of surgical manipulation can significantly lower brainstem tolerance in the individual patient

Radiotherapy gel dosimetry

International Nuclear Information System (INIS)

Baldock, C.

2002-01-01

In radiotherapy, the primary objective is to deliver a prescribed dose of radiation to a tumour or lesion within a patient while minimising the dose delivered to the surrounding healthy tissue. Traditional radiotherapy treatments usually involve simple external or internal irradiations of a tumour. External irradiations are normally achieved in the clinic with photon or electron beams produced by high energy linear accelerators. The photon or electron beams are collimated into regular shapes as they emerge from the treatment head of the unit which is supported by a gantry that can be rotated isocentrically to any position. A discrete number of photon or electron beams with different angles of incidence that intersect at the iso-centre are used to produce a region of high dose around the tumour volume (positioned at the iso-centre). Internal irradiations are normally achieved in the clinic by implanting radioactive sources in and around the tumour or lesion. Such irradiations are characterised by very high doses local to the tumour. Radioactive sources are also used to prevent post-angioplasty restenosis by inserting sources into arteries. Usually when treating a tumour, a compromise is made between tumour control and complications arising from normal tissue damage. One measure of this compromise, the therapeutic ratio, is defined as the radiation dose producing complications in 50% of patients divided by the dose providing tumour control in 50% of the patients. The therapeutic ratio depends on the radiobiological characteristics of the cancerous tissue and surrounding healthy tissues and on the radiation dose distribution achieved by the radiotherapy treatment. It is generally believed that the therapeutic ratio can be minimised by optimising the conformation of the radiation dose distribution to the target volume. This is difficult with traditional radiotherapy techniques since they do not produce dose distributions that adequately cover tumour volumes of complex

Cardiac dose sparing and avoidance techniques in breast cancer radiotherapy

International Nuclear Information System (INIS)

Shah, Chirag; Badiyan, Shahed; Berry, Sameer; Khan, Atif J.; Goyal, Sharad; Schulte, Kevin; Nanavati, Anish; Lynch, Melanie; Vicini, Frank A.

2014-01-01

Breast cancer radiotherapy represents an essential component in the overall management of both early stage and locally advanced breast cancer. As the number of breast cancer survivors has increased, chronic sequelae of breast cancer radiotherapy become more important. While recently published data suggest a potential for an increase in cardiac events with radiotherapy, these studies do not consider the impact of newer radiotherapy techniques commonly utilized. Therefore, the purpose of this review is to evaluate cardiac dose sparing techniques in breast cancer radiotherapy. Current options for cardiac protection/avoidance include (1) maneuvers that displace the heart from the field such as coordinating the breathing cycle or through prone patient positioning, (2) technological advances such as intensity modulated radiation therapy (IMRT) or proton beam therapy (PBT), and (3) techniques that treat a smaller volume around the lumpectomy cavity such as accelerated partial breast irradiation (APBI), or intraoperative radiotherapy (IORT). While these techniques have shown promise dosimetrically, limited data on late cardiac events exist due to the difficulties of long-term follow up. Future studies are required to validate the efficacy of cardiac dose sparing techniques and may use surrogates for cardiac events such as biomarkers or perfusion imaging

Application of biological dose concept in dose optimization for conformal radiotherapy of prostate carcinoma

International Nuclear Information System (INIS)

Li Yunhai; Liao Yuan; Zhou Lijun; Pan Ziqiang; Feng Yan

2003-01-01

Objective: On basis of physical dose optimization, LQ model was used to investigate the difference between the curves of biological effective dose and physical isodose. The influence of applying the biological dose concept on three dimensional conformal radiotherapy of prostate carcinoma was discussed. Methods: Four treatment plannings were designed for physical dose optimization: three fields, four-box fields, five fields and six fields. Target dose uniformity and protection of the critical tissue-rectum were used as the principal standard for designing the treatment planning. Biological effective dose (BED) was calculated by LQ model. The difference between the BED curve drawn in the central layer and the physical isodose curve was studied. The difference between the adjusted physical dose (APD) and the physical dose was also studied. Results: Five field planning was the best in target dose uniformity and protection of the critical tissue-rectum. The physical dose was uniform in the target, but the biological effective doses revealed great discrepancy in the biological model. Adjusted physical dose distribution also displayed larger discrepancy than the physical dose unadjusted. Conclusions: Intensified Modulated Radiotherapy (IMRT) technique with inversion planning using biological dose concept may be much more advantageous to reach a high tumor control probability and low normal tissue complication probability

CONSERVATIVE TREATMENT IN LOCALLY AND LOCALLY-ADVANCED PROSTATE CANCER USING CONFORMAL RADIOTHERAPY

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Tkachev Sergey Ivanovich

2013-01-01

Full Text Available The combination of androgen deprivation and radiotherapy increase the probability of diseases full regresses and survival rate. Modern technical and technological opportunities of 3D CRT allow to increase total dose to prostate up to 72-76Gy vs. radiotherapy of 66-70Gy. In this study we compare the rates of post radiation toxicity and the efficiency of treatment for the patients receiving conventional radiotherapy and 3D CRT. The use of 3D CRT has not only result to increase of 10-years recurrence free survival rate from 74% (I grope to 86,5% (II grope, р=0,01, but also to increase of 10-years overall survival, 70% versus 78,4% (р=0,04. The proposed version of conformal 3D CRT radiation therapy made ​​it possible compared to conventional 2D RT radiation therapy by increasing SOD radiation to the tumor, accuracy and compliance with the quality assurance of radiation therapy significantly reduce rates of recurrence and significantly increase the performance of 10-year overall and disease-free survival.

Development of three-dimensional radiotherapy techniques in breast cancer

Science.gov (United States)

Coles, Charlotte E.

Radiotherapy following conservation surgery decreases local relapse and death from breast cancer. Currently, the challenge is to minimise the morbidity caused by this treatment without losing efficacy. Despite many advances in radiation techniques in other sites of the body, the majority of breast cancer patients are still planned and treated using 2-dimensional simple radiotherapy techniques. In addition, breast irradiation currently consumes 30% of the UK's radiotherapy workload. Therefore, any change to more complex treatment should be of proven benefit. The primary objective of this research is to develop and evaluate novel radiotherapy techniques to decrease irradiation of normal structures and improve localisation of the tumour bed. I have developed a forward-planned intensity modulated (IMRT) breast radiotherapy technique, which has shown improved dosimetry results compared to standard breast radiotherapy. Subsequently, I have developed and implemented a phase III randomised controlled breast IMRT trial. This National Cancer Research Network adopted trial will answer an important question regarding the clinical benefit of breast IMRT. It will provide DNA samples linked with high quality clinical outcome data, for a national translational radiogenomics study investigating variation in normal tissue toxicity. Thus, patients with significant late normal tissue side effects despite good dose homogeneity will provide the best model for finding differences due to underlying genetics. I evaluated a novel technique using high definition free-hand 3-dimensional (3D) ultrasound in a phantom study, and the results suggested that this is an accurate and reproducible method for tumour bed localisation. I then compared recognised methods of tumour bed localisation with the 3D ultrasound method in a clinical study. The 3D ultrasound technique appeared to accurately represent the shape and spatial position of the tumour cavity. This tumour bed localisation research

Radiotherapy in prostate cancer. Innovative techniques and current controversies

International Nuclear Information System (INIS)

Geinitz, Hans

2015-01-01

Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors

International Nuclear Information System (INIS)

Caudrelier, J.M.; Auliard, A.; Sarrazin, T.; Gibon, D.; Coche-Dequeant, B.; Castelain, B.

2001-01-01

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors. Purpose. - We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours. Patients and methods.- Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan. Gross tumor volume, planning target volume and normal tissue volumes were defined. Dose was prescribed according to report 50 of the International Commission on Radiation Units and Measurements (ICRU). We compared surfaces of sagittal view targets defined on PT2D and PT3D and called them S2D and S3D, respectively. Irradiated volumes by 90% isodoses (VE-90%) and normal tissue volumes irradiated by 20, 50, 90% isodoses were calculated and compared using Student's paired t-test. Results. -There was a concordance of 84% of target surfaces defined on PT2D and PT3D. Percentages of target surface under- or-over defined by PT2D were 16 and 13% respectively. VE-90% was decreased by 15% (p = 0.07) with PT3D. Normal brain volume irradiated by 90% isodose was decreased by 27% with PT3D (p = 0.04). Conclusion.- For radiotherapy of cerebral tumors using only coplanar beams, PT3D leads to a reduction of normal brain tissue irradiated. We recommend PT3D for radiotherapy of cerebral tumors, particularly for low-grade or benign tumors (meningiomas, neuromas, etc.). (authors)

Digital linear accelerator: The advantages for radiotherapy

International Nuclear Information System (INIS)

Andric, S.; Maksimovic, M.; Dekic, M.; Clark, T.

1998-01-01

Technical performances of Digital Linear Accelerator were presented to point out its advantages for clinical radiotherapy treatment. The accelerator installation is earned out at Military Medical Academy, Radiotherapy Department, by Medes and Elekta companies. The unit offers many technical advantages with possibility of introduction new conformal treatment techniques as stereotactic radiosurgery, total body and total skin irradiation. In the paper are underlined advantages in relation to running conventional accelerator units at Yugoslav radiotherapy departments, both from technical and medical point of view. (author)

Acute toxicity in pelvic radiotherapy; a randomised trial of conformal versus conventional treatment

International Nuclear Information System (INIS)

Tait, Diana M.; Nahum, Alan E.; Meyer, Lesley C.; Law, Matthew; Dearnaley, David P.; Horwich, Alan; Mayles, W. Philip; Yarnold, John R.

1997-01-01

Background: A prospective, randomized clinical trial to assess the effect of reducing the volume of irradiated normal tissue on acute reactions in pelvic radiotherapy accrued 266 evaluable patients between 1988 and 1993. Purpose: This is the definitive analysis to assess the differences between the conformal and conventional arms of the trial. Materials and methods: In both arms, patients were treated with 6 MV X-rays using a 3-field technique (in all but 5 cases) consisting of an anterior and two wedged lateral or posterior oblique fields; in the conventional arm, rectangular fields were employed, whereas in the conformal arm, the fields were shaped with customized blocks drawn according to the beam's-eye-view of the target volume. The most common dosage was 65 Gy in 2-Gy fractions 5 times a week, although a subgroup (of ca. bladder patients) were treated with 30-36 Gy in once-a-week 6 Gy fractions. Each patient completed a comprehensive acute toxicity scoring questionnaire concentrating on bowel and bladder problems, tiredness and nausea, before the start of treatment, weekly during and for 3 weeks after the end of treatment and then monthly for a further 2 months. Compliance was excellent. Results: There were no differences between the patients in the two arms with respect to age, gender, tumour type (52% prostate, 41% bladder, 5% rectum, 2% other) fractionation/dosage, anterior field size, weight, or baseline symptoms. Substantial differences in normal-tissue volumes (rectum, bladder, etc.) were achieved: median high-dose volume (HDV) of 689 cm 3 for the conformal technique versus 792 cm 3 for the conventional. A clear pattern of an increase in symptoms during RT, followed by a decrease after RT, was observed for the patient group as a whole. However, a very extensive analysis has not revealed any (statistically) significant differences between the two arms in level of symptoms, nor in medication prescribed. The disparity between our findings and those of other

Metastatic breast cancer in the eye and orbit, use three-dimensional conformal radiotherapy. Our first experience

International Nuclear Information System (INIS)

Correa Pablos, Tamara; Caceres Toledo, Maria

2009-01-01

The eye and orbit metastases are a significant clinical problem, both by the inability and the deterioration in the quality of life that occur. The most common malignant tumors in the eye and orbit is metastasis. Cancer breast cancer is the most common tumor metastatic to the eye and orbit in a 40% and 50% of cases according to different series. With the introduction of Three-Dimensional Conformal Radiotherapy (3D-CRT) in our hospital from In 2007 we were able to treat patients with cancer different regions with the technique (2D) was impossible because caused irreparable damage to surrounding healthy tissue in this way thanks to potential of 3D technology to shape the planning volume will ensure greater protection for critical organs. (Author)

Therapeutic effect analysis of three dimensional conformal radiotherapy non-small cell lung cancer

International Nuclear Information System (INIS)

Yao Zhijun; Cao Yongzhen; Zhang Wenxue; Liang Feng

2012-01-01

Objective: To analyse the treatment effect of non-small cell lung cancer of three dimensional conformal radiotherapy (3D-CRT) and to study the effect of patient survival related factors. Methods: Retrospective analysis was mack for 136 cases of non-small cell lung cancer, all accept 3D-CRT, through the case data collection and long-term follow-up, using the single factor and multiple factor analysis survival time and its influencing factors. Results: The recent curative effects of 136 cases of patients with three dimensional conformal radiotherapy: Complete response (CR) 14.7% (20/136), partial response (PR) 60.3 (82/136), stable disease(SD) 19.9% (27/136), progression disease (PD) 5.1% (7/136), total effective rate is 75% (102/136). One, two, three, five year survival rate is 79.4%, 45.4%, 22.1%, 12.5%. Side effects: Class 1 radiated esophagitis 35 cases, Class 2 radiated esophagitis 16 cases, Class 3 and above radiated esophagitis 0 case. Class I radiated pneumonia 20 cases, Class 2 radiated pneumonia 9 cases, Class 3 radiated pneumonia 0 case. Single factor analysis shows the influence of gender, age, pathology, phase, dose, and first-phase curative effect to the survival time are of a statistical significance, Multiple factor analysis showed KPS score, phase, dose, first-phase curative effect are the survival time independent factors. Conclusion: 3D-CRT for patients with non-small cell lung carcinoma is a safe, effective treatment method, Side effects are relatively low, and the patients survival time is long after radiotherapy. (authors)

Radiotherapy in prostate cancer. Innovative techniques and current controversies

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Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

2015-04-01

Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

Historical review of radiotherapy

International Nuclear Information System (INIS)

Onai, Yoshio

1993-01-01

The techniques of radiotherapy have been improved by development of particle accelerators, radionuclides and computers. This paper presents a historical review of the physical and technical aspects of radiotherapy in Japan. Changes in the kinds of radiation, such as X-rays, gamma rays, electrons, neutrons and protons used for external radiotherapy, and the equipment involved are described chronologically, and historical changes in the quality of radiotherapy apparatus are outlined. Patient data acquisition equipment, such as X-ray simulator and X-ray CT, beam modifying devices, patient setup devices, and devices to verify treatment fields and patient doses are reviewed historically. Radiation sources for brachytherapy and internal radiotherapy, and remotely controlled afterloading systems are reviewed chronologically. Historical changes in methods to evaluate absorbed doses, dose monitor systems and beam data acquisition systems are outlined. Changes in methods of calculating dose distributions for external X-ray and electron therapy, brachytherapy and internal radiotherapy by unsealded radionuclides are described and calculation techniques for treatment planning system are reviewed. Annual figures in the numbers of radiotherapy equipment, such as telecobalt and telecesium units, linear accelerators, betatrons, microtrons, stereotactic gamma units, conformation radiotherapy units, remotely controlled afterloading systems, and associated equipment such as X-ray simulators and treatment planning systems are provided, as are changes in the number of accelerators by maximum X-ray energy and maximum electron energy, and in the number of licensed hospitals and clinics using small sealed sources. Changes in techniques of external radiotherapy and brachytherapy are described briefly from the point of view of dose distributions. (author)

Beam shaping for conformal fractionated stereotactic radiotherapy: a modeling study

International Nuclear Information System (INIS)

Hacker, Fred L.; Kooy, Hanne M.; Bellerive, Marc R.; Killoran, Joseph H.; Leber, Zachary H.; Shrieve, Dennis C.; Tarbell, Nancy J.; Loeffler, Jay S.

1997-01-01

Purpose: The patient population treated with fractionated stereotactic radiotherapy (SRT) is significantly different than that treated with stereotactic radiosurgery (SRS). Generally, lesions treated with SRT are larger, less spherical, and located within critical regions of the central nervous system; hence, they offer new challenges to the treatment planner. Here a simple, cost effective, beam shaping system has been evaluated relative to both circular collimators and an ideal dynamically conforming system for effectiveness in providing conformal therapy for these lesions. Methods and Materials: We have modeled a simple system for conformal arc therapy using four independent jaws. The jaw positions and collimator angle are changed between arcs but held fixed for the duration of each arc. Eleven previously treated SRT cases have been replanned using this system. The rectangular jaw plans were then compared to the original treatment plans which used circular collimators. The plans were evaluated with respect to tissue sparing at 100%, 80%, 50%, and 20% of the prescription dose. A plan was also done for each tumor in which the beam aperture was continuously conformed to the beams eye view projection of the tumor. This was used as an ideal standard for conformal therapy in the absence of fluence modulation. Results: For tumors with a maximum extent of over 3.5 cm the rectangular jaw plans reduced the mean volume of healthy tissue involved at the prescription dose by 57% relative to the circular collimator plans. The ideal conformal plans offered no significant further improvement at the prescription dose. The relative advantage of the rectangular jaw plans decreased at lower isodoses so that at 20% of the prescription dose tissue involvement for the rectangular jaw plans was equivalent to that for the circular collimator plans. At these isodoses the ideal conformal plans gave substantially better tissue sparing. Conclusion: A simple and economical field shaping

Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning.

Science.gov (United States)

Myers, Pamela A; Mavroidis, Panayiotis; Papanikolaou, Nikos; Stathakis, Sotirios

2014-09-08

Currently, radiotherapy treatment plan acceptance is based primarily on dosimetric performance measures. However, use of radiobiological analysis to assess benefit in terms of tumor control and harm in terms of injury to normal tissues can be advantageous. For pediatric craniospinal axis irradiation (CSI) patients, in particular, knowing the technique that will optimize the probabilities of benefit versus injury can lead to better long-term outcomes. Twenty-four CSI pediatric patients (median age 10) were retrospectively planned with three techniques: three-dimensional conformal radiation therapy (3D CRT), volumetric-modulated arc therapy (VMAT), and helical tomotherapy (HT). VMAT plans consisted of one superior and one inferior full arc, and tomotherapy plans were created using a 5.02cm field width and helical pitch of 0.287. Each plan was normalized to 95% of target volume (whole brain and spinal cord) receiving prescription dose 23.4Gy in 13 fractions. Using an in-house MATLAB code and DVH data from each plan, the three techniques were evaluated based on biologically effective uniform dose (D=), the complication-free tumor control probability (P+), and the width of the therapeutically beneficial range. Overall, 3D CRT and VMAT plans had similar values of D= (24.1 and 24.2 Gy), while HT had a D= slightly lower (23.6 Gy). The average values of the P+ index were 64.6, 67.4, and 56.6% for 3D CRT, VMAT, and HT plans, respectively, with the VMAT plans having a statistically significant increase in P+. Optimal values of D= were 28.4, 33.0, and 31.9 Gy for 3D CRT, VMAT, and HT plans, respectively. Although P+ values that correspond to the initial dose prescription were lower for HT, after optimizing the D= prescription level, the optimal P+ became 94.1, 99.5, and 99.6% for 3D CRT, VMAT, and HT, respectively, with the VMAT and HT plans having statistically significant increases in P+. If the optimal dose level is prescribed using a radiobiological evaluation method, as

The intercomparison of the dose distributions between conformation techniques with pions and photons

International Nuclear Information System (INIS)

Karasawa, K.; Nakagawa, K.; Akanuma, A.

1990-01-01

To compare conformation radiation treatment with pions vs photons, dose volume histograms (DVH) to the critical organs, including the spinal cord, kidney, and intestine, were examined in a patient with retroperitoneal soft tissue sarcoma. For photon conformation treatment, the following techniques were used: 360 degree rotation conformation technique (photon conformation), 4 fixed field technique (photon 4-field), and 2-axis conformation technique (photon 2-axial conformation). According to the DVH reduction method, complication probability was estimated. The concave portion of the target was conformed by pion conformation treatment, but not by photon conformation treatment. Pion conformation for the intestine showed the best DVH, whereas photon 4-field technique showed the worst DVH. For the kidney, pion conformation showed better DVH as compared with any other photon conformation treatment technique. In the spinal cord, photon 2-axial conformation was far superior, followed by pion conformation and then photon conformation and 4-field technique. A 2-axial technique showed a bigger inhomogeneity inside the target volume which is critical in curative treatment. TD 50 was 72 Gy for pion conformation, 53 Gy for photon conformation, 51 Gy for photon 4-field, and 68 Gy for photon 2-axial conformation. Complication probabilities for these conformation techniques at 60 Gy were 3%, 85%, 97%, and 9%. In view of tumor control probabilities, pion seems to have the biggest therapeutic ratio among these techniques. (N.K.)

Improvement in toxicity in high risk prostate cancer patients treated with image-guided intensity-modulated radiotherapy compared to 3D conformal radiotherapy without daily image guidance.

Science.gov (United States)

Sveistrup, Joen; af Rosenschöld, Per Munck; Deasy, Joseph O; Oh, Jung Hun; Pommer, Tobias; Petersen, Peter Meidahl; Engelholm, Svend Aage

2014-02-04

Image-guided radiotherapy (IGRT) facilitates the delivery of a very precise radiation dose. In this study we compare the toxicity and biochemical progression-free survival between patients treated with daily image-guided intensity-modulated radiotherapy (IG-IMRT) and 3D conformal radiotherapy (3DCRT) without daily image guidance for high risk prostate cancer (PCa). A total of 503 high risk PCa patients treated with radiotherapy (RT) and endocrine treatment between 2000 and 2010 were retrospectively reviewed. 115 patients were treated with 3DCRT, and 388 patients were treated with IG-IMRT. 3DCRT patients were treated to 76 Gy and without daily image guidance and with 1-2 cm PTV margins. IG-IMRT patients were treated to 78 Gy based on daily image guidance of fiducial markers, and the PTV margins were 5-7 mm. Furthermore, the dose-volume constraints to both the rectum and bladder were changed with the introduction of IG-IMRT. The 2-year actuarial likelihood of developing grade > = 2 GI toxicity following RT was 57.3% in 3DCRT patients and 5.8% in IG-IMRT patients (p analysis, 3DCRT was associated with a significantly increased risk of developing grade > = 2 GI toxicity compared to IG-IMRT (p analysis there was no difference in biochemical progression-free survival between 3DCRT and IG-IMRT. The difference in toxicity can be attributed to the combination of the IMRT technique with reduced dose to organs-at-risk, daily image guidance and margin reduction.

Conformity index: A review

International Nuclear Information System (INIS)

Feuvret, Loic; Noel, Georges; Mazeron, Jean-Jacques; Bey, Pierre

2006-01-01

We present a critical analysis of the conformity indices described in the literature and an evaluation of their field of application. Three-dimensional conformal radiotherapy, with or without intensity modulation, is based on medical imaging techniques, three-dimensional dosimetry software, compression accessories, and verification procedures. It consists of delineating target volumes and critical healthy tissues to select the best combination of beams. This approach allows better adaptation of the isodose to the tumor volume, while limiting irradiation of healthy tissues. Tools must be developed to evaluate the quality of proposed treatment plans. Dosimetry software provides the dose distribution in each CT section and dose-volume histograms without really indicating the degree of conformity. The conformity index is a complementary tool that attributes a score to a treatment plan or that can compare several treatment plans for the same patient. The future of conformal index in everyday practice therefore remains unclear

Comparative dosimetric study of three-dimensional conformal, dynamic conformal arc, and intensity-modulated radiotherapy for brain tumor treatment using Novalis system

International Nuclear Information System (INIS)

Ding Meisong; Newman, Francis M.S.; Kavanagh, Brian D.; Stuhr, Kelly M.S.; Johnson, Tim K.; Gaspar, Laurie E.

2006-01-01

Purpose: To investigate the dosimetric differences among three-dimensional conformal radiotherapy (3D-CRT), dynamic conformal arc therapy (DCAT), and intensity-modulated radiotherapy (IMRT) for brain tumor treatment. Methods and Materials: Fifteen patients treated with Novalis were selected. We performed 3D-CRT, DCAT, and IMRT plans for all patients. The margin for the planning target volume (PTV) was 1 mm, and the specific prescription dose was 90% for all plans. The target coverage at the prescription dose, conformity index (CI), and heterogeneity index were analyzed for all plans. Results: For small tumors (PTV ≤2 cm 3 ), the three dosimetric parameters had approximate values for both 3D-CRT and DCAT plans. The CI for the IMRT plans was high. For medium tumors (PTV >2 to ≤100 cm 3 ), the three plans were competitive with each other. The IMRT plans had a greater CI, better target coverage at the prescription dose, and a better heterogeneity index. For large tumors (PTV >100 cm 3 ), the IMRT plan had good target coverage at the prescription dose and heterogeneity index and approximate CI values as those in the 3D-CRT and DCAT plans. Conclusion: The results of our study have shown that DCAT is suitable for most cases in the treatment of brain tumors. For a small target, 3D-CRT is useful, and IMRT is not recommended. For larger tumors, IMRT is superior to 3D-CRT and very competitive in sparing critical structures, especially for big tumors

Intensity modulation in breast radiotherapy: Development of an innovative field-in-field technique at Institut Gustave-Roussy; Modulation d'intensite en radiotherapie mammaire: developpement d'une methode innovante de champ dans le champ a l'institut Gustave-Roussy

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Heymann, S.; Bourhis, J.; Bourgier, C. [Departement d' oncologie radiotherapie, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Verstraet, R.; Pichenot, C.; Vergne, E.; Lefkopoulos, D. [Departement de physique, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Husson, F.; Kafrouni, H.; Mahe, J.; Kandalaft, B. [Societe Dosisoft, 45/47, avenue Carnot, 94230 Cachan (France); Marsiglia, H. [Departement d' oncologie radiotherapie, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Universite de Florence, Florence (Italy)

2011-12-15

Purpose. - To assess the potential dosimetric gain of pre-segmentation modulated radiotherapy (OAPS, DosiSoft{sup TM}) of breast, compared to routine 3D conformal radiotherapy. Patients and methods. - Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm{sup 3}; range [100-1049 cm{sup 3}]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the pre-segmentation algorithm of DosiSoft{sup TM} (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V 30 Gy for the heart, and mean dose, V 20 Gy and V 30 Gy for lungs. Results. - Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P < 0,0001). For heart and lung, OAPS decreased irradiation (mean cardiac dose 1,3 vs 1,6 Gy [P < 0,0001] and pulmonary V 20 Gy 6,6 vs 7,1 [P < 0,0001]). Conclusion. - OAPS (DosiSoft{sup TM}) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk. (authors)

Conformal radiotherapy of locally advanced bile duct carcinoma

International Nuclear Information System (INIS)

Bouras, N.; Caudry, M.; Bonnel, C.; Trouette, R.; Demeaux, H.; Maire, J.P.; Saric, J.; Rullier, E.

2002-01-01

Purpose. - Retrospective study of 23 patients treated with conformal radiotherapy for a locally advanced bile duct carcinoma. Patients and methods. - Eight cases were irradiated after a radical resection (RO), because they were N+; seven after microscopically incomplete resection (R1) ; seven were not resected (R2). A dose of 45 of 50 Gy was delivered, followed by a boost up to 60 Gy in R1 and R2 groups. Concomitant chemotherapy was given in 15 cases. Results.-Late toxicity included a stenosis of the duodenum, and one of the biliary anastomosis. Two patients died from cholangitis, the mechanism of which remains unclear. Five patients are in complete remission, six had a local relapse, four developed a peritoneal carcinosis, and six distant metastases. Actuarial survival rate is 75%, 28% and 7% at 1, 3 and 5 years, respectively (median: 16.5 months). Seven patients are still alive with a 4 to 70 months follow-up. Survival is similar in the 3 small subgroups. The poor local control among RON+ cases might be related to the absence of a boost to the 'tumor bed'. In R1 patients, relapses were mainly distant metastases, where'as local and peritoneal recurrences predominated in R2. Conclusion. - Conformal radio-chemotherapy delivering 60 Gy represents a valuable palliative approach in locally advanced biliary carcinoma. (authors)

Health-Related Quality of Life in Patients With Locally Advanced Prostate Cancer After 76 Gy Intensity-Modulated Radiotherapy vs. 70 Gy Conformal Radiotherapy in a Prospective and Longitudinal Study

International Nuclear Information System (INIS)

Lips, Irene; Dehnad, Human; Kruger, Arto Boeken; Moorselaar, Jeroen van; Heide, Uulke van; Battermann, Jan; Vulpen, Marco van

2007-01-01

Purpose: To compare quality of life (QoL) after 70 Gy conformal radiotherapy with QoL after 76 Gy intensity-modulated radiotherapy (IMRT) in patients with locally advanced prostate carcinoma. Methods and Materials: Seventy-eight patients with locally advanced prostate cancer were treated with 70 Gy three-field conformal radiotherapy, and 92 patients received 76 Gy IMRT with fiducial markers for position verification. Quality of life was measured by RAND-36, the European Organization for Research and Treatment of Cancer core questionnaire (EORTC QLQ-C30(+3)), and the prostate-specific EORTC QLQ-PR25, before radiotherapy (baseline) and 1 month and 6 months after treatment. Quality of life changes in time (baseline vs. 1 month and baseline vs. 6 months) of ≥10 points were considered clinically relevant. Results: Differences between the treatment groups for QoL changes over time occurred in several QoL domains. The 76-Gy group revealed no significant deterioration in QoL compared with the 70-Gy group. The IMRT 76-Gy group even demonstrated a significantly better change in QoL from baseline to 1 month in several domains. The conformal 70-Gy group revealed temporary deterioration in pain, role functioning, and urinary symptoms; for the IMRT 76-Gy group a better QoL in terms of change in health existed after 1 month, which persisted after 6 months. For both treatment groups temporary deterioration in physical role restriction occurred after 1 month, and an improvement in emotional role restriction occurred after 6 months. Sexual activity was reduced after treatment for both groups and remained decreased after 6 months. Conclusions: Intensity-modulated radiotherapy and accurate position verification seem to provide a possibility to increase the radiation dose for prostate cancer without deterioration in QoL

Comparative study of four advanced 3d-conformal radiation therapy treatment planning techniques for head and neck cancer

International Nuclear Information System (INIS)

Herrassi, Mohamed Yassine; Bentayeb, Farida; Malisan, Maria Rosa

2013-01-01

For the head-and-neck cancer bilateral irradiation, intensity-modulated radiation therapy (IMRT) is the most reported technique as it enables both target dose coverage and organ-at-risk (OAR) sparing. However, during the last 20 years, three-dimensional conformal radiotherapy (3DCRT) techniques have been introduced, which are tailored to improve the classic shrinking field technique, as regards both planning target volume (PTV) dose conformality and sparing of OARs, such as parotid glands and spinal cord. In this study, we tested experimentally in a sample of 13 patients, four of these advanced 3DCRT techniques, all using photon beams only and a unique isocentre, namely Bellinzona, Forward-Planned Multisegments (FPMS), ConPas, and field-in-field (FIF) techniques. Statistical analysis of the main dosimetric parameters of PTV and OARs DVHs as well as of homogeneity and conformity indexes was carried out in order to compare the performance of each technique. The results show that the PTV dose coverage is adequate for all the techniques, with the FPMS techniques providing the highest value for D95%; on the other hand, the best sparing of parotid glands is achieved using the FIF and ConPas techniques, with a mean dose of 26 Gy to parotid glands for a PTV prescription dose of 54 Gy. After taking into account both PTV coverage and parotid sparing, the best global performance was achieved by the FIF technique with results comparable to that of IMRT plans. This technique can be proposed as a valid alternative when IMRT equipment is not available or patient is not suitable for IMRT treatment. (author)

A method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy

International Nuclear Information System (INIS)

Lu Yong; Song, Paul Y.; Li Shidong; Spelbring, Danny R.; Vijayakumar, Srinivasan; Haraf, Daniel J.; Chen, George T.Y.

1995-01-01

Purpose: To develop a method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy. Methods and Materials: Dose-surface histograms of the rectum, which state the rectal surface area irradiated to any given dose, were calculated for a group of 27 patients treated with a four-field box technique to a total (tumor minimum) dose ranging from 68 to 70 Gy. Occurrences of rectal toxicities as defined by the Radiation Therapy Oncology Group (RTOG) were recorded and examined in terms of dose and rectal surface area irradiated. For a specified end point of rectal complication, the complication probability was analyzed as a function of dose irradiated to a fixed rectal area, and as a function of area receiving a fixed dose. Lyman's model of normal tissue complication probability (NTCP) was used to fit the data. Results: The observed occurrences of rectal complications appear to depend on the rectal surface area irradiated to a given dose level. The patient distribution of each toxicity grade exhibits a maximum as a function of percentage surface area irradiated, and the maximum moves to higher values of percentage surface area as the toxicity grade increases. The dependence of the NTCP for the specified end point on dose and percentage surface area irradiated was fitted to Lyman's NTCP model with a set of parameters. The curvature of the NTCP as a function of the surface area suggests that the rectum is a parallel structured organ. Conclusions: The described method of analyzing rectal surface area irradiated yields interesting insight into understanding rectal complications in prostate conformal radiotherapy. Application of the method to a larger patient data set has the potential to facilitate the construction of a full dose-surface-complication relationship, which would be most useful in guiding clinical practice

Radiotherapy of intensity modulated VS conformational in the treatment of carcinoma of the prostate. A dosimetric comparison; Radioterapia de intensidad modulada VS conformacional en el tratamiento de carcinoma de prostata. Una camparacion dosimetrica

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Rodriguez Martin, G.; Garcia Vicente, F.; Zapatero Laborda, A.; Bermudez Luna, R.; Roch Gonzalez, M.; Perez Gonzalez, L.; Torres Escobar, J. J.

2013-07-01

The intensity modulated (IMRT) radiation therapy is a technique of high conformation which, by its nature, has as one of its main directions prostate cancer radiotherapy treatment. The purpose of this work is presents results of the dosimetric indicators collected in our hospital a number of patients of carcinoma of the prostate with standard three-dimensional Conformal technique (3D-CRT) and IMRT. Aims to demonstrate and quantify with a statistical methodology that, establishing an adequate Protocol of IMRT, significant reductions in risk organ doses can be obtained by keeping the same prescription to the white volume. (Author)

Conformal radiotherapy by intensity modulation of pediatrics tumors; Radiotherapie conformationnelle par modulation d'intensite des tumeurs pediatriques

Energy Technology Data Exchange (ETDEWEB)

Leseur, J.; Le Prise, E. [Centre Eugene-Marquis, 35 - Rennes (France); Carrie, C. [Centre Leon Berard, 69 - Lyon (France); Bernier, V. [Centre Alexis-Vautrin, 54 - Nancy (France); Beneyton, V. [Centre Paul-Strauss, 67 - Strasbourg (France); Mahe, M.A.; Supiot, S. [Centre Rene-Gauducheau, 44 - Nantes (France)

2009-10-15

The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)

Clinical variability of target volume description and treatment plans in conformal radiotherapy in muscle invasive bladder cancer

International Nuclear Information System (INIS)

Logue, John P; Sharrock, Carole L; Cowan, Richard A.; Read, Graham; Marrs, Julie; Mott, David

1996-01-01

Purpose/Objective: The delineation of tumor and the production of a treatment plan to encompass this is the prime step in radiotherapy planning. Conformal radiotherapy is developing rapidly and although plentiful research has addressed the implementation of the radiotherapy prescription, scant attention has been made to the fundamental step of production, by the clinician, of an appropriate target volume. As part of an ongoing randomized trial of conformal radiotherapy, in bladder cancer, we have therefore assessed the interphysician variability of radiologists and radiation oncologists (RO) in assessing Gross Tumor Volume(GTV) (ICRU 50) and the adherence of the radiation oncologists to the study protocol of producing a Planning Target Volume (PTV). Materials and Methods: Four patients with T3 carcinoma of bladder who had been entered into the trial were identified. The clinical details, MR scans and CT scans were made available. Eight RO and 3 dedicated diagnostic oncology radiologists were invited to directly outline the GTV onto CT images on a planning computer consul. The RO in addition created a PTV following the trial protocol of 15mm margin around the GTV. Three RO sub-specialized in Urological radiotherapy; all RO had completed training. Volumes were produced, for each clinician, and comparison of these volumes and their isocenters were analyzed. In addition the margins allowed were measured and compared. Results: There was a maximum variation ratio (largest to smallest volume outlined) of the GTV in the four cases of 1.74 among radiologists and 3.74 among oncologists. There was a significant difference (p=0.01) in mean GTV between RO and the radiologists. The mean GTV of the RO exceeded the radiologists by a factor of 1.29 with a mean difference of 13.4 cm 3 The between observer variance within speciality comprised only 9.9% of the total variance in the data having accounted for case and observers speciality. The variation ratio in PTV among oncologists

The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

International Nuclear Information System (INIS)

Vranova, Jana; Vinakurau, Stepan; Richter, Jan; Starec, Miroslav; Fiserova, Anna; Rosina, Jozef

2011-01-01

Our research compared whole pelvic (WP) and prostate-only (PO) 3-dimensional conformal radiotherapy (3DCRT) techniques in terms of the incidence and evolution of acute and late toxicity of the rectum and urinary bladder, and identified the PTV-parameters influencing these damages and changes in antitumor immune response. We analyzed 197 prostate cancer patients undergoing 3DCRT for gastrointestinal (GI) and genitourinary (GU) toxicities, and conducted a pilot immunological study including flow cytometry and an NK cell cytotoxicity assay. Acute and late toxicities were recorded according to the RTOG and the LENT-SOMA scales, respectively. Univariate and multivariate analyses were conducted for factors associated with toxicity. In the WP group, an increase of acute rectal toxicity was observed. A higher incidence of late GI/GU toxicity appeared in the PO group. Only 18 patients (WP-7.76% and PO-11.11%) suffered severe late GI toxicity, and 26 patients (WP-11.21% and PO-16.05%) severe late GU toxicity. In the majority of acute toxicity suffering patients, the diminution of late GI/GU toxicity to grade 1 or to no toxicity after radiotherapy was observed. The 3DCRT technique itself, patient age, T stage of TNM classification, surgical intervention, and some dose-volume parameters emerged as important factors in the probability of developing acute and late GI/GU toxicity. The proportion and differentiation of NK cells positively correlated during 3DCRT and negatively so after its completion with dose-volumes of the rectum and urinary bladder. T and NKT cells were down-regulated throughout the whole period. We found a negative correlation between leukocyte numbers and bone marrow irradiated by 44-54 Gy and a positive one for NK cell proportion and doses of 5-25 Gy. The acute GU, late GU, and GI toxicities up-regulated the T cell (CTL) numbers and NK cytotoxicity. Our study demonstrates the association of acute and late damage of the urinary bladder and rectum, with

Influence of conformal radiotherapy technique on survival after chemoradiotherapy for patients with stage III non-small cell lung cancer in the National Cancer Data Base.

Science.gov (United States)

Sher, David J; Koshy, Matthew; Liptay, Michael J; Fidler, Mary Jo

2014-07-01

Definitive chemoradiotherapy is a core treatment modality for patients with stage III non-small cell lung cancer (NSCLC). Although radiotherapy (RT) technologies have advanced dramatically, to the authors' knowledge relatively little is known regarding the importance of irradiation technique on outcome, particularly given the competing risk of distant metastasis. The National Cancer Data Base was used to determine predictors of overall survival (OS) in patients with AJCC stage III NSCLC who were treated with chemoradiotherapy, focusing on the importance of conformal RT (CRT). Patients with stage III NSCLC who were treated with chemoradiotherapy between 2003 and 2005 in the National Cancer Data Base were included. RT technique was defined as conventional, 3-dimensional-conformal, or intensity-modulated RT (IMRT), the latter 2 combined as CRT. Cox proportional hazards regression was performed for univariable and multivariable analyses of OS. The median, 3-year, and 5-year survival outcomes for the 13,292 patients were 12.9 months, 19%, and 11%, respectively. The 3-year and 5-year survival probabilities of patients receiving CRT versus no CRT were 22% versus 19% and 14% versus 11%, respectively (P < .0001). On multivariable analysis, CRT was found to be significantly associated with improved OS (hazards ratio, 0.89). This effect was confirmed on sensitivity analyses, including restricting the cohort to minimum 6-month survivors, young patients with stage IIIA disease, and propensity score-matching. Institutional academic status and patient volume were not found to be associated with OS. CRT was found to be independently associated with a survival advantage. These results reflect the importance of optimal locoregional therapy in patients with stage III NSCLC and provide motivation for further study of advanced RT technologies in patients with NSCLC. © 2014 American Cancer Society.

Highly Conformal Craniospinal Radiotherapy Techniques Can Underdose the Cranial Clinical Target Volume if Leptomeningeal Extension through Skull Base Exit Foramina is not Contoured.

Science.gov (United States)

Noble, D J; Ajithkumar, T; Lambert, J; Gleeson, I; Williams, M V; Jefferies, S J

2017-07-01

Craniospinal irradiation (CSI) remains a crucial treatment for patients with medulloblastoma. There is uncertainty about how to manage meningeal surfaces and cerebrospinal fluid (CSF) that follows cranial nerves exiting skull base foramina. The purpose of this study was to assess plan quality and dose coverage of posterior cranial fossa foramina with both photon and proton therapy. We analysed the radiotherapy plans of seven patients treated with CSI for medulloblastoma and primitive neuro-ectodermal tumours and three with ependymoma (total n = 10). Four had been treated with a field-based technique and six with TomoTherapy™. The internal acoustic meatus (IAM), jugular foramen (JF) and hypoglossal canal (HC) were contoured and added to the original treatment clinical target volume (Plan_CTV) to create a Test_CTV. This was grown to a test planning target volume (Test_PTV) for comparison with a Plan_PTV. Using Plan_CTV and Plan_PTV, proton plans were generated for all 10 cases. The following dosimetry data were recorded: conformity (dice similarity coefficient) and homogeneity index (D 2  - D 98 /D 50 ) as well as median and maximum dose (D 2% ) to Plan_PTV, V 95% and minimum dose (D 99.9% ) to Plan_CTV and Test_CTV and Plan_PTV and Test_PTV, V 95% and minimum dose (D 98% ) to foramina PTVs. Proton and TomoTherapy™ plans were more conformal (0.87, 0.86) and homogeneous (0.07, 0.04) than field-photon plans (0.79, 0.17). However, field-photon plans covered the IAM, JF and HC PTVs better than proton plans (P = 0.002, 0.004, 0.003, respectively). TomoTherapy™ plans covered the IAM and JF better than proton plans (P = 0.000, 0.002, respectively) but the result for the HC was not significant. Adding foramen CTVs/PTVs made no difference for field plans. The mean D min dropped 3.4% from Plan_PTV to Test_PTV for TomoTherapy™ (not significant) and 14.8% for protons (P = 0.001). Highly conformal CSI techniques may underdose meninges and CSF in the dural

Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

CERN Document Server

Lemoigne, Yves

2009-01-01

This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

International Nuclear Information System (INIS)

Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P.

2011-01-01

Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long-term results are needed to assess

Practical application of the tool calculation Monte Carlo MCVerif for checking for radiotherapy treatment

International Nuclear Information System (INIS)

Laliena Bielsa, V. M.; Garcia Romero, A.; Villa Gazulla, D.; Ortega Pardilla, P.; Calvo Carrillo, S.; Millan Cebrian, E.; Hernandez Vitorial, A.; Canellas Aznoz, M.

2013-01-01

The object of this work is to verify a patient group representative of the usual techniques of 3D conformal radiotherapy and IMRT performed in the radiotherapy service our hospital and thus validate the algorithm used commercial planning system. (Author)

Gastro-intestinal and genito-urinary morbidity after 3D conformal radiotherapy of prostate cancer: observations of a randomized trial

International Nuclear Information System (INIS)

Koper, Peter C.; Jansen, Peter; Putten, Wim van; Os, Marjolein van; Wijnmaalen, Arend J.; Lebesque, Joos V.; Levendag, Peter C.

2004-01-01

Background and purpose: The late morbidity of a randomized study was analyzed after a follow up of 2 years. The difference in intestinal morbidity was analyzed as a function of the treatment arm and dose volume parameters. The correlation with acute toxicity and (pre-existing) bowel complaints was investigated. Patients and methods: 266 T1-4N0M0 prostate cancer patients were randomized for conventional (open fields) and 3D conformal radiotherapy using beams eye view blocked fields with the same dose (66 Gy) and gross target volume-planning target volume margin (15 mm). Apart from the RTOG toxicity scoring system a patient self-assessment questionnaire was used to obtain detailed information on morbidity. Results: At 2 years there is only a trend for less rectal toxicity (grade≥1) in favor of the conformal radiotherapy (grade 1, 47 versus 40% and grade 2, 10 versus 7% for conventional and conformal radiotherapy, respectively (P=0.1). A significant relation was found between late rectal toxicity (grade≥1) and the volume of the anus and rectum exposed to≥90% tumor dose (TD). A highly significant relationship is observed between acute rectum and anal toxicity and late rectal toxicity. The patient self-assessment questionnaire analysis revealed that patients are most bothered by compliance related symptoms like urgency, soiling and fecal loss. In a multivariate analysis, all other variables loose significance, when anal volume exposed to≥90% TD and pre-treatment defaecation frequency are accounted for. Late anal toxicity is low and related only to acute anal toxicity. Late bladder toxicity is related solely to pre-treatment frequency and overall urological symptoms. The incidence of grade 2 toxicity increases with a factor 2.5-4 when (stool or urine) frequency is unfavorable at the start of treatment. Conclusions: Conformal radiotherapy at the dose level of 66 Gy does not significantly decrease the incidence of rectal, anal and bladder toxicity compared to

Dosimetric Verification and Evaluation of the 3-D Conformal Parotid Gland-Sparing Irradiation Technique for Bilateral Neck Treatment at University Hospital Centre Zagreb

International Nuclear Information System (INIS)

Kovacevic, N; Hrsak, H.; Bibic, J.

2011-01-01

3-D Conformal Parotid Gland-Sparing Irradiation Technique for Bilateral Neck (ConPas) is an alternative to Intensity-modulated radiotherapy (IMRT), and is in routine use at University Hospital Centre Rebro (KBC-Rebro), Zagreb. This technique includes highly asymmetric wedged conformal multi-leaf fields and demands very precise application. The aim of this paper is to present the dosimetric verification method of ConPas (and evaluation of ConPas applicability) as performed at KBC, taking into account the precision of the Treatment Planning System (TPS), possibilities of linear accelerator and patient set-up error. Results for two patients are shown in some details.ConPas is a rather sophisticated method and demands high precision in the whole radiotherapy process. Verification of ConPas using IMRT Verification Matrix Phantom shows good agreement between measured and predicted doses inside and outside PTV regions of the head and neck. Furthermore, a careful track of the positioning during the treatment shows that the overall set-up error is very small (practically negligible). When possible, one parotid gland may be partially spared, and therefore its function preserved at least to some extent. (author)

A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

International Nuclear Information System (INIS)

Macknelly, Andrew; Day, Jane

2009-01-01

Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

Non small cells stage I bronchial cancers: three-dimensional radiotherapy and radiotherapy in stereotactic conditions; Cancers bronchiques non a petites cellules de stade I: radiotherapie tridimensionnelle et radiotherapie en conditions stereotaxiques

Energy Technology Data Exchange (ETDEWEB)

Schipman, B.; Bosset, J.F. [CHU, 25 - Besancon (France); Marchesi, V.; Beckendorf, V.; Desandes, E.; Peiffert, D. [CRLCC Alexis-Vautrin, 54 - Vandaeuvre-les-Nancy (France); Bosset, M. [CHU, 26 - Valence (France)

2010-10-15

The authors report a comparison between three-dimensional conformation radiotherapy and robotic irradiation in stereotactic conditions (with CyberKnife) for patients suffering from a bronchial cancer with no small cells of stage I. Acute and late toxicity have been recorded, and the monitoring comprised a clinic examination and a thoracic scanography. The external radiotherapy results in an important local control rate and an acceptable toxicity. Some prospective studies are still needed to compare three-dimensional conformation respiratory-gated radiotherapy and radiotherapy in stereotactic conditions. Short communication

A mono isocentric radiotherapy technique for craniospinal irradiation using asymmetric jaws

International Nuclear Information System (INIS)

Isin, G; Oezyar, E.; Guerdalli, S.; Arslan, G.; Uzal, D.; Atahan, I. L.

1995-01-01

Dose distribution across the junction of matching of craniospinal fields (lateral cranial fields and posterior spinal field) is important as severe complications may result if the beams overlap or disease may recurs if the gapping is too conservative. Various techniques have been used to achieve an effective transverse plane match and half-beam block technique is one of these techniques. Here, we describe a mono isocentric technique for the treatment of craniospinal fields using the asymmetric jaws of our linear accelerator (Philips SL-25). Before the clinical application of this non-standard technique, basic dosimetry parameters are evaluated. Asymmetric collimator dose distributions for various asymmetric field sizes were obtained and compared with symmetric dose distributions for 6 MV x-ray. A computerized 3-D water phantom with a pair of ionization chambers (reference and field) was used for dose profiles, isodose distributions and Percentage Depth Dose (PDD) for various asymmetric field sizes and different off axis distances. The measured values of off axis ratios for the interested depths were used in MU calculations. This new mono isocentric technique provides an ideal dose distribution at match-line as there is no need to move the patient during treatment. Use of heavy secondary cerrobend blocks (beam splitters) is eliminated. This technique provides the ease of consequent daily set-up's and fulfills the requirements for a conformal radiotherapy

Cranial radiotherapy guided by computed tomography with or without fields conformation in pediatric

International Nuclear Information System (INIS)

Fernandez, Diego; Caussa, Lucas; Murina, Patricia; Zunino, Silvia

2007-01-01

Many malignancies in children can be cured by radiotherapy, acute toxicity and the significant effect of delayed treatment are worrying for the patient, family and society. Therefore, the end of the pediatric radiotherapy is to maintain or improve the cure rate of cancer, diminishing the aftermath of treatment. The goal of this study is to measure differences in doses to the healthy tissue of the central nervous system with two radiotherapy techniques, both guided by computed tomography [es

Auto-optimisation for three-dimensional conformal radiotherapy of nasopharyngeal carcinoma

Energy Technology Data Exchange (ETDEWEB)

Wu, V.W.C. E-mail: orvinwu@polyu.edu.hk; Kwong, D.W.L.; Sham, J.S.T.; Mui, A.W.L

2003-08-01

Purpose: The purpose of this study was to evaluate the application of auto-optimisation in the treatment planning of three-dimensional conformal radiotherapy (3DCRT) of nasopharyngeal carcinoma (NPC). Methods: Twenty-nine NPC patients were planned by both forward planning and auto-optimisation methods. The forward plans, which consisted of three coplanar facial fields, were produced according to the routine planning criteria. The auto-optimised plans, which consisted of 5-15 (median 9) fields, were generated by the planning system after prescribing the dose requirements and the importance weightings of the planning target volume and organs at risk. Plans produced by the two planning methods were compared by the dose volume histogram, tumour control probability (TCP), conformity index and normal tissue complication probability (NTCP). Results: The auto-optimised plans reduced the average planner's time by over 35 min. It demonstrated better TCP and conformity index than the forward plans (P=0.03 and 0.04, respectively). Besides, the parotid gland and temporo-mandibular (TM) joint were better spared with the mean dose reduction of 31.8 and 17.7%, respectively. The slight trade off was the mild dose increase in spinal cord and brain stem with their maximum doses remaining within the tolerance limits. Conclusions: The findings demonstrated the potentials of auto-optimisation for improving target dose and parotid sparing in the 3DCRT of NPC with saving of the planner's time.

Auto-optimisation for three-dimensional conformal radiotherapy of nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Wu, V.W.C.; Kwong, D.W.L.; Sham, J.S.T.; Mui, A.W.L.

2003-01-01

Purpose: The purpose of this study was to evaluate the application of auto-optimisation in the treatment planning of three-dimensional conformal radiotherapy (3DCRT) of nasopharyngeal carcinoma (NPC). Methods: Twenty-nine NPC patients were planned by both forward planning and auto-optimisation methods. The forward plans, which consisted of three coplanar facial fields, were produced according to the routine planning criteria. The auto-optimised plans, which consisted of 5-15 (median 9) fields, were generated by the planning system after prescribing the dose requirements and the importance weightings of the planning target volume and organs at risk. Plans produced by the two planning methods were compared by the dose volume histogram, tumour control probability (TCP), conformity index and normal tissue complication probability (NTCP). Results: The auto-optimised plans reduced the average planner's time by over 35 min. It demonstrated better TCP and conformity index than the forward plans (P=0.03 and 0.04, respectively). Besides, the parotid gland and temporo-mandibular (TM) joint were better spared with the mean dose reduction of 31.8 and 17.7%, respectively. The slight trade off was the mild dose increase in spinal cord and brain stem with their maximum doses remaining within the tolerance limits. Conclusions: The findings demonstrated the potentials of auto-optimisation for improving target dose and parotid sparing in the 3DCRT of NPC with saving of the planner's time

Three dimensional conformal radiotherapy for the treatment of prostate cancer: low risk of chronic rectal morbidity observed in a large series of patients

International Nuclear Information System (INIS)

Sandler, Howard M.; McLaughlin, P. William; Ten Haken, Randall K.; Addison, Heather; Forman, Jeffrey; Lichter, Allen

1995-01-01

Purpose: Three dimensional conformal radiotherapy (3D CRT) may provide a technique to increase the dose delivered to target tissues while sparing uninvolved normal structures. To evaluate the role of 3D treatment in reducing the treatment toxicity, we analyzed the chronic rectal morbidity observed in a large group of patients undergoing radiotherapy for prostate cancer. Methods and Materials: From 1987 through 1992, 721 prostate cancer patients were treated with 3D CRT at the University of Michigan or Providence Hospital. All had axial computed tomography (CT) specifically for RT planning, multiple structures contoured on the axial images, and beam's-eye-view conformal beams edited to provide 3D dose coverage. Using current American Joint Commission (AJCC) staging, 537 patients had T1-T2 tumors, 123 had T3-T4 tumors, and 60 were treated postprostatectomy. Pelvic lymph nodes were treated in 462 patients. Prostate boosts were delivered with four-field axial, six-field axial, or four-field oblique, nonaxial fields. The median dose was 68.40 Gy (range 59.4-80.4). Median follow-up was 20.4 months; 175 were followed more than 3 years. All complications have been graded conservatively using the RTOG system. Results: Using a Cox proportional hazard's model, patient age, T-stage, prescribed dose, pelvic treatment, and boost technique were analyzed. The factor most strongly related to risk of morbidity was dose (p = 0.05); however, the boost technique was also related: the four-field oblique field had the lowest relative risk. Most episodes of rectal morbidity have been mild: 82 Grade 1 or 2. There have been only 14 more serious complications including 12 Grade 3 and 2 Grade 4. The actuarial risk of a Grade 3 or 4 complication is 3% at 3 and 5 years. Conclusions: A very small proportion of patients treated with 3D CRT had significant rectal morbidity related to RT, supporting the use of conformal treatment planning and dose delivery as a mechanism to minimize complications

Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique

DEFF Research Database (Denmark)

Brodin, N. Patrik; af Rosenschold, Per Munck; Blomstrand, Malin

2014-01-01

BackgroundWe investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.MethodsWe included 17 pediatric medulloblastoma...

Dosimetric evaluation of tomography and four-box field conformal radiotherapy in locally advanced rectal cancer

International Nuclear Information System (INIS)

Yu, Mina; Lee, Hyo Chun; Chung, Mi Joo; Kim, Sung Hwan; Lee, Jong Hoon; Jang, Hong Seok; Jeon, Dong Min; Cheon, Geum Seong

2013-01-01

To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, Vn Gy, Dmin, Dmax, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p 0.001). But, V26.25 Gy and V27.5 Gywere not significantly different between the two modalities. Tomotherapy showed higher Dmax and lower Dmin. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

Dosimetric evaluation of tomography and four-box field conformal radiotherapy in locally advanced rectal cancer

Energy Technology Data Exchange (ETDEWEB)

Yu, Mina; Lee, Hyo Chun; Chung, Mi Joo; Kim, Sung Hwan; Lee, Jong Hoon [Dept. of Radiation Oncology, St. Vincent' s Hospital, The Catholic University of Korea College of Medicine, Suwon (Korea, Republic of); Jang, Hong Seok; Jeon, Dong Min; Cheon, Geum Seong [Dept. of Radiation Oncology, Seoul St. Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

2013-12-15

To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, Vn Gy, Dmin, Dmax, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p 0.001). But, V26.25 Gy and V27.5 Gywere not significantly different between the two modalities. Tomotherapy showed higher Dmax and lower Dmin. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

Three dimensional-conformal radiotherapy combined with capecitabine chemotherapy for locally advanced (unresectable) rectal cancer

International Nuclear Information System (INIS)

Zhu Yaqun; Tian Ye; Zhang Junning; Wang Bin

2010-01-01

Objective: To evaluate the compliance and efficacy of chemoradiotherapy for locally advanced (unresectable) rectal cancer. Methods: Thirty eight patients with locally advanced (T4 or recurred) rectal cancer received three dimensional-conformal radiotherapy (for 46 ∼ 50Gy/5 weeks and was boosted to the tumor 16 ∼ 18Gy/2 weeks, 2Gy/fraction, 5 days/week) in combination with capecitabine 1 650mg · m -2 · d -1 , day 1-14, every 3 weeks. Results: The overall response rate was 57.9%, with CR 5 (13.2%), PR 17(44.7%), SD 10 (26.3%), PD 6 (15.8%), median survival time, the 1-year overall survival rate and the 2-year overall survival rate were 18 months, 64.43%, 18.78%, respectively. The remission rate of pain and improvement rate of performance status were 100% and 52.8%. Treatment-related toxicity mainly showed at diarrhea, neutrocytopenia and hand-foot syndrome, the incidence of grade 3 toxicity were 15.8%, 15.8%, 7.9%, respectively. there were no grade 4 toxicity and treatment-related death. Conclusion: Combination of three dimensional-conformal radiotherapy with capecitabine is active in advanced rectal cancer, It is a well-tolerated regimen. (authors)

Clinical results of conformal versus intensity-modulated radiotherapy using a focal simultaneous boost for muscle-invasive bladder cancer in elderly or medically unfit patients.

Science.gov (United States)

Lutkenhaus, Lotte J; van Os, Rob M; Bel, Arjan; Hulshof, Maarten C C M

2016-03-18

For elderly or medically unfit patients with muscle-invasive bladder cancer, cystectomy or chemotherapy are contraindicated. This leaves radical radiotherapy as the only treatment option. It was the aim of this study to retrospectively analyze the treatment outcome and associated toxicity of conformal versus intensity-modulated radiotherapy (IMRT) using a focal simultaneous tumor boost for muscle-invasive bladder cancer in patients not suitable for cystectomy. One hundred eighteen patients with T2-4 N0-1 M0 bladder cancer were analyzed retrospectively. Median age was 80 years. Treatment consisted of either a conformal box technique or IMRT and included a simultaneous boost to the tumor. To enable an accurate boost delivery, fiducial markers were placed around the tumor. Patients were treated with 40 Gy in 20 fractions to the elective treatment volumes, and a daily tumor boost up to 55-60 Gy. Clinical complete response was seen in 87 % of patients. Three-year overall survival was 44 %, with a locoregional control rate of 73 % at 3 years. Toxicity was low, with late urinary and intestinal toxicity rates grade ≥ 2 of 14 and 5 %, respectively. The use of IMRT reduced late intestinal toxicity, whereas fiducial markers reduced acute urinary toxicity. Radical radiotherapy using a focal boost is feasible and effective for elderly or unfit patients, with a 3-year locoregional control of 73 %. Toxicity rates were low, and were reduced by the use of IMRT and fiducial markers.

Potential clinical efficacy of intensity-modulated conformal therapy

International Nuclear Information System (INIS)

Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Mendenhall, William M.; Zlotecki, Robert A.

1998-01-01

Purpose: The purpose of this study was to examine the potential benefit of using intensity-modulated conformal therapy for a variety of lesions currently treated with stereotactic radiosurgery or conventional radiotherapy. Methods and Materials: Intensity-modulated conformal treatment plans were generated for small intracranial lesions, as well as head and neck, lung, breast, and prostate cases, using the Peacock Plan[reg] treatment-planning system (Nomos Corporation). For small intracranial lesions, intensity-modulated conformal treatment plans were compared with stereotactic radiosurgery treatment plans generated for patient treatment at the University of Florida Shands Cancer Center. For other sites (head and neck, lung, breast, and prostate), plans generated using the Peacock Plan[reg] were compared with conventional treatment plans, as well as beam's-eye-view conformal treatment plans. Plan comparisons were accomplished through conventional qualitative review of two-dimensional (2D) dose distributions in conjunction with quantitative techniques, such as dose-volume histograms, dosimetric statistics, normal tissue complication probabilities, tumor control probabilities, and objective numerical scoring. Results: For small intracranial lesions, there is little difference between intensity-modulated conformal treatment planning and radiosurgery treatment planning in the conformation of high isodose lines with the target volume. However, stereotactic treatment planning provides a steeper dose gradient outside the target volume and, hence, a lower normal tissue toxicity index. For extracranial sites, objective numerical scores for beam's-eye-view and intensity-modulated conformal planning techniques are superior to scores for conventional treatment plans. The beam's-eye-view planning technique prevents geographic target misses and better excludes healthy tissues from the treatment portal. Compared with scores for the beam's-eye-view planning technique, scores for

Development of dose audits for complex treatment techniques in radiotherapy

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Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M., E-mail: stefanic@cae.cnea.gov.ar [Centro Regional de Referencia con Patrones Secundarios para Dosimetria - CNEA, Presbitero Juan Gonzalez y Aragon 15, B1802AYA Ezeiza (Argentina)

2014-08-15

This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

Development of dose audits for complex treatment techniques in radiotherapy

International Nuclear Information System (INIS)

Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M.

2014-08-01

This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

Adjuvant Chemoradiation for Gastric Cancer Using Epirubicin, Cisplatin, and 5-Fluorouracil Before and After Three-Dimensional Conformal Radiotherapy With Concurrent Infusional 5-Fluorouracil: A Multicenter Study of the Trans-Tasman Radiation Oncology Group

International Nuclear Information System (INIS)

Leong, Trevor; Joon, Daryl Lim; Willis, David; Jayamoham, Jayasingham; Spry, Nigel; Harvey, Jennifer; Di Iulio, Juliana; Milner, Alvin; Mann, G. Bruce; Michael, Michael

2011-01-01

Purpose: The INT0116 study has established postoperative chemoradiotherapy as the standard of care for completely resected gastric adenocarcinoma. However, the optimal chemoradiation regimen remains to be defined. We conducted a prospective, multicenter study to evaluate an alternative chemoradiation regimen that combines more current systemic treatment with modern techniques of radiotherapy delivery. Methods and Materials: Patients with adenocarcinoma of the stomach who had undergone an R0 resection were eligible. Adjuvant therapy consisted of one cycle of epirubicin, cisplatin, and 5-FU (ECF), followed by radiotherapy with concurrent infusional 5-FU, and then two additional cycles of ECF. Radiotherapy was delivered using precisely defined, multiple-field, three-dimensional conformal techniques. Results: A total of 54 assessable patients were enrolled from 19 institutions. The proportion of patients commencing Cycles 1, 2, and 3 of ECF chemotherapy were 100%, 81%, and 67% respectively. In all, 94% of patients who received radiotherapy completed treatment as planned. Grade 3/4 neutropenia occurred in 66% of patients with 7.4% developing febrile neutropenia. Most neutropenic episodes (83%) occurred in the post-radiotherapy period during cycles 2 and 3 of ECF. Grade 3/4 gastrointestinal toxicity occurred in 28% of patients. In all, 35% of radiotherapy treatment plans contained protocol deviations that were satisfactorily amended before commencement of treatment. At median follow-up of 36 months, the 3-year overall survival rate was estimated at 61.6%. Conclusions: This adjuvant regimen using ECF before and after three-dimensional conformal chemoradiation is feasible and can be safely delivered in a cooperative group setting. A regimen similar to this is currently being compared with the INT0116 regimen in a National Cancer Institute-sponsored, randomized Phase III trial.

Intensity-modulated conformal radiotherapy in the anal canal cancer. Report of technological assessment. Updating of the 2006 report

International Nuclear Information System (INIS)

2015-07-01

As intensity-modulated conformal radiotherapy (IMCR) has already been technologically assessed in 2006 with a positive opinion for some treatments and a negative one for others, and as this technique displays some interesting properties for the treatment of pelvic cancers (optimisation of dose distribution, preservation of sane tissues, reduction of secondary effects during irradiation), this report proposes an assessment of clinical safety and efficiency of IMCR in the treatment of an anal canal cancer. After a discussion of generalities, of histological and epidemiological data, and of knowledge regarding treatment and follow-up of this cancer, the report presents the IMCR technique, some regulatory aspects, and its applications to the considered cancer. The methodology adopted for this assessment is then presented. Based on various studies and clinical results, the IMCR clinical safety and efficiency in the treatment of the anal canal cancer are discussed and assessed. Recommendations produced by different medical professional bodies are reported. Opinion of experts and a synthesis of stakeholders are then proposed

Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

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Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P. [IRCC, Candiolo (Italy)

2011-10-15

Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was < 10 mm in 33 patients (53%) and > 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long

Sonographic Assessment of Parotid and Submandibular Glands in Patients Undergoing 3D Conformal Radiotherapy

Directory of Open Access Journals (Sweden)

Johari M

2016-06-01

Full Text Available The aim of this study was to evaluate sonographic changes in parotid and submandibular salivary glands in patients undergoing radiotherapy for head and neck malignancies. In addition, salivary changes subsequent to radiotherapy were evaluated objectively and subjectively. Twenty patients(13males and 7females with head and neck malignancies, who had been referred to the Radiotherapy/Oncology Department of the Shahid Madani Hospital in Tabriz, Iran, were included in the study. Length, width, echotexture, echogenicity and margins of parotid and submandibular glands were evaluated before and after radiotherapy using sonography. Peak-systolic velocity(PSV,end-diastolic velocity(EDV and resistive index(RI were also assessed by Doppler sonography. Xerostomia subsequent to radiotherapy was evaluated with the use of two techniques: patients’ self-reported scoring and objective measurement of resting saliva. There was a significant decrease in the width of the parotid gland after radiotherapy compared to baseline(P=0.005.Although the length of the parotid gland and the dimensions of submandibular gland decrease, the differences were not significant. In addition, the echogenicity, echotexture and the margin of the glands change to hypoechoic, heterogenic and irregular, respectively, subsequent to radiotherapy. The Doppler technique showed decrease in PSV and RI and an increase in EDV; however, only the decrease in RI in the submandibular gland was statistically significant(P=0.002.The results showed a significant decrease in salivary flow after radiotherapy(P<0.001.In addition, based on the patients reports, the severity of xerostomia increased significantly after radiotherapy(P<0.001. Songraphic changes of parotid and submandibular glands after radiotherapy should be considered in ultrasound examinations. The damages to the parotid and submandibular glands had significant influence in patient post 3D-CRT.

SU-F-T-87: Comparison of Advanced Radiotherapy Techniques for Post- Mastectomy Breast Cancer Patients

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Heins, D; Zhang, R [Louisiana State University, Baton Rouge, LA (United States); Hogstrom, K; Sanders, M [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States)

2016-06-15

Purpose: To determine if bolus electron conformal therapy (Bolus-ECT) combined with intensity modulated x-ray therapy (IMXT) and flattening filter free volumetric modulated arc therapy (FFF-VMAT (6x and 10x)) can maintain equal or better dose coverage than standard volumetric modulated arc therapy (Std-VMAT) while reducing doses to organs at risk (OARs). Methods: Bolus-ECT with IMXT, FFF-VMAT, and Std-VMAT treatment plans were produced for ten post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic. The treatment plans were created on commercially available treatment planning system (TPS) and all completed treatment plans were reviewed and approved by a radiation oncologist. The plans were evaluated based on planning target volume (PTV) coverage, tumor control probability (TCP), dose homogeneity index (DHI), conformity index (CI), and dose to organs at risk (OAR). Results: All techniques produced clinically acceptable PMRT plans. Overall, Bolus-ECT with IMXT exhibited higher maximum dose compared to all VMAT techniques. Bolus-ECT with IMXT and FFF-VMAT10x had slightly improved TCP over FFF-VMAT6x and Std-VMAT. However, all VMAT techniques showed improved CI and DHI over Bolus-ECT with IMXT. All techniques showed very similar mean lung dose. Bolus-ECT with IMXT exhibited a reduced mean heart dose over Std-VMAT. Both FFF-VMAT techniques had higher mean heart dose compared to Std-VMAT. In addition, Bolus-ECT with IMXT was able to reduce mean dose to the contralateral breast compared to Std-VMAT and both FFF-VMAT techniques had comparable but slightly reduced dose compared to Std-VMAT. Conclusion: This work has shown that Bolus-ECT with IMXT produces clinically acceptable plans while reducing OAR doses. Both FFF-VMAT techniques are comparable to Std-VMAT with slight improvements. Even though all VMAT techniques produce more homogenous and conformal dose distributions, Bolus-ECT with IMXT is a viable option for treating post-mastectomy patients

Comparison of rectal volume definition techniques and their influence on rectal toxicity in patients with prostate cancer treated with 3D conformal radiotherapy: a dose-volume analysis

International Nuclear Information System (INIS)

Onal, Cem; Topkan, Erkan; Efe, Esma; Yavuz, Melek; Sonmez, Serhat; Yavuz, Aydin

2009-01-01

To evaluate the impact of four different rectum contouring techniques and rectal toxicities in patients with treated with 3D conformal radiotherapy (3DCRT). Clinical and dosimetric data were evaluated for 94 patients who received a total dose 3DCRT of 70 Gy, and rectal doses were compared in four different rectal contouring techniques: the prostate-containing CT sections (method 1); 1 cm above and below the planning target volume (PTV) (method 2); 110 mm starting from the anal verge (method 3); and from the anal verge to the sigmoid flexure (method 4). The percentage of rectal volume receiving RT doses (30–70 Gy) and minimum, mean rectal doses were assessed. Median age was 69 years. Percentage of rectal volume receiving high doses (≥ 70 Gy) were higher with the techniques that contoured smaller rectal volumes. In methods 2 and 3, the percentage of rectal volume receiving ≥ 70 Gy was significantly higher in patients with than without rectal bleeding (method 2: 30.8% vs. 22.5%, respectively (p = 0.03); method 3: 26.9% vs. 18.1%, respectively (p = 0.006)). Mean rectal dose was significant predictor of rectal bleeding only in method 3 (48.8 Gy in patients with bleeding vs. 44.4 Gy in patients without bleeding; p = 0.02). Different techniques of rectal contouring significantly influence the calculation of radiation doses to the rectum and the prediction of rectal toxicity. Rectal volume receiving higher doses (≥ 70 Gy) and mean rectal doses may significantly predict rectal bleeding for techniques contouring larger rectal volumes, as was in method 3

Integral Dose and Radiation-Induced Secondary Malignancies: Comparison between Stereotactic Body Radiation Therapy and Three-Dimensional Conformal Radiotherapy

Directory of Open Access Journals (Sweden)

Stefano G. Masciullo

2012-11-01

Full Text Available The aim of the present paper is to compare the integral dose received by non-tumor tissue (NTID in stereotactic body radiation therapy (SBRT with modified LINAC with that received by three-dimensional conformal radiotherapy (3D-CRT, estimating possible correlations between NTID and radiation-induced secondary malignancy risk. Eight patients with intrathoracic lesions were treated with SBRT, 23 Gy × 1 fraction. All patients were then replanned for 3D-CRT, maintaining the same target coverage and applying a dose scheme of 2 Gy × 32 fractions. The dose equivalence between the different treatment modalities was achieved assuming α/β = 10Gy for tumor tissue and imposing the same biological effective dose (BED on the target (BED = 76Gy10. Total NTIDs for both techniques was calculated considering α/β = 3Gy for healthy tissue. Excess absolute cancer risk (EAR was calculated for various organs using a mechanistic model that includes fractionation effects. A paired two-tailed Student t-test was performed to determine statistically significant differences between the data (p ≤ 0.05. Our study indicates that despite the fact that for all patients integral dose is higher for SBRT treatments than 3D-CRT (p = 0.002, secondary cancer risk associated to SBRT patients is significantly smaller than that calculated for 3D-CRT (p = 0.001. This suggests that integral dose is not a good estimator for quantifying cancer induction. Indeed, for the model and parameters used, hypofractionated radiotherapy has the potential for secondary cancer reduction. The development of reliable secondary cancer risk models seems to be a key issue in fractionated radiotherapy. Further assessments of integral doses received with 3D-CRT and other special techniques are also strongly encouraged.

Intensity modulated radiotherapy (IMRT) in bilateral retinoblastoma

International Nuclear Information System (INIS)

Atalar, Banu; Ozyar, Enis; Gunduz, Kaan; Gungor, Gorkem

2010-01-01

External beam radiotherapy (EBRT) for retinoblastoma has traditionally been done with conventional radiotherapy techniques which resulted high doses to the surrounding normal tissues. A 20 month-old girl with group D bilateral retinoblastoma underwent intensity modulated radiotherapy (IMRT) to both eyes after failing chemoreduction and focal therapies including cryotherapy and transpupillary thermotherapy. In this report, we discuss the use of IMRT as a method for reducing doses to adjacent normal tissues while delivering therapeutic doses to the tumour tissues compared with 3-dimensional conformal radiotherapy (3DCRT). At one year follow-up, the patient remained free of any obvious radiation complications. Image guided IMRT provides better dose distribution than 3DCRT in retinoblastoma eyes, delivering the therapeutic dose to the tumours and minimizing adjacent tissue damage

Conformal radiotherapy of urinary bladder cancer

International Nuclear Information System (INIS)

Muren, Ludvig Paul; Smaaland, Rune; Dahl, Olav

2004-01-01

Recent advances in radiotherapy (RT) are founded on the enhanced tumour visualisation capabilities of new imaging modalities and the precise deposition of individualised radiation dose distributions made possible with the new systems for RT planning and delivery. These techniques have a large potential to also improve the results of RT of urinary bladder cancer. Major challenges to take full advantage of these advances in the management of bladder cancer are to control, and, as far as possible, reduce bladder motion, and to reliably account for the related intestine and rectum motion. If these obstacles are overcome, it should be possible in the near future to offer selected patients with muscle invading bladder cancer an organ-sparing, yet effective combined-modality treatment as an alternative to radical surgery

Prostate cancer: variables to keep in mind at the moment to decide the external radiotherapy dose

International Nuclear Information System (INIS)

Donato, H.; Barros, J.M.; Fernandez Bibiloni, C.; Barrios, E.; Martinez, A.; Broda, E.; Cardiello, C.; Alva, R.; Chiozza, J.; Filomia, M.L.; Rafailovici, L.; Dosoretz, B.

2007-01-01

The objective of this work is to evaluate forecast factors and other variables in the decision of the final dose for prostate cancer treatment with 3D conformal radiotherapy techniques of modulated intensity. To determine the optimal dose, direct and indirect variables related to the disease should be considered. Also the equipment and the radiotherapy technique will impact on this decision [es

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Science.gov (United States)

Bartlett, Frederick R.; Colgan, Ruth M.; Donovan, Ellen M.; Carr, Karen; Landeg, Steven; Clements, Nicola; McNair, Helen A.; Locke, Imogen; Evans, Philip M.; Haviland, Joanne S.; Yarnold, John R.; Kirby, Anna M.

2014-01-01

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery. PMID:25046661

Incidental irradiation of internal mammary lymph nodes in breast cancer: conventional two-dimensional radiotherapy versus conformal three-dimensional radiotherapy

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Leite, Elton Trigo Teixeira; Ugino, Rafael Tsuneki; Lopes, Mauricio Russo; Pelosi, Edilson Lopes; Silva, Joao Luis Fernandes da, E-mail: eltontt@gmail.com [Hospital Sirio-Libanes, Sao paulo, SP (Brazil). Departamento de Radiologia e Oncologia; Santana, Marco Antonio; Ferreira, Denis Vasconcelos; Carvalho, Heloisa de Andrade [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Departamento de Radiologia e Oncologia

2016-05-15

Objective: to evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. Materials and Methods: This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). Results: Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. Conclusion: Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique. (author)

Clinical results of conformal versus intensity-modulated radiotherapy using a focal simultaneous boost for muscle-invasive bladder cancer in elderly or medically unfit patients

International Nuclear Information System (INIS)

Lutkenhaus, Lotte J.; Os, Rob M. van; Bel, Arjan; Hulshof, Maarten C. C. M.

2016-01-01

For elderly or medically unfit patients with muscle-invasive bladder cancer, cystectomy or chemotherapy are contraindicated. This leaves radical radiotherapy as the only treatment option. It was the aim of this study to retrospectively analyze the treatment outcome and associated toxicity of conformal versus intensity-modulated radiotherapy (IMRT) using a focal simultaneous tumor boost for muscle-invasive bladder cancer in patients not suitable for cystectomy. One hundred eighteen patients with T2-4 N0-1 M0 bladder cancer were analyzed retrospectively. Median age was 80 years. Treatment consisted of either a conformal box technique or IMRT and included a simultaneous boost to the tumor. To enable an accurate boost delivery, fiducial markers were placed around the tumor. Patients were treated with 40 Gy in 20 fractions to the elective treatment volumes, and a daily tumor boost up to 55–60 Gy. Clinical complete response was seen in 87 % of patients. Three-year overall survival was 44 %, with a locoregional control rate of 73 % at 3 years. Toxicity was low, with late urinary and intestinal toxicity rates grade ≥ 2 of 14 and 5 %, respectively. The use of IMRT reduced late intestinal toxicity, whereas fiducial markers reduced acute urinary toxicity. Radical radiotherapy using a focal boost is feasible and effective for elderly or unfit patients, with a 3-year locoregional control of 73 %. Toxicity rates were low, and were reduced by the use of IMRT and fiducial markers. The online version of this article (doi:10.1186/s13014-016-0618-6) contains supplementary material, which is available to authorized users

[Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

Science.gov (United States)

Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

2017-10-01

Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Comparison of intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy as adjuvant therapy for gastric cancer.

Science.gov (United States)

Minn, A Yuriko; Hsu, Annie; La, Trang; Kunz, Pamela; Fisher, George A; Ford, James M; Norton, Jeffrey A; Visser, Brendan; Goodman, Karyn A; Koong, Albert C; Chang, Daniel T

2010-08-15

The current study was performed to compare the clinical outcomes and toxicity in patients treated with postoperative chemoradiotherapy for gastric cancer using intensity-modulated radiotherapy (IMRT) versus 3-dimensional conformal radiotherapy (3D CRT). Fifty-seven patients with gastric or gastroesophageal junction cancer were treated postoperatively: 26 with 3D CRT and 31 with IMRT. Concurrent chemotherapy was capecitabine (n=31), 5-fluorouracil (5-FU) (n=25), or none (n=1). The median radiation dose was 45 Gy. Dose volume histogram parameters for kidney and liver were compared between treatment groups. The 2-year overall survival rates for 3D CRT versus IMRT were 51% and 65%, respectively (P=.5). Four locoregional failures occurred each in the 3D CRT (15%) and the IMRT (13%) patients. Grade>or=2 acute gastrointestinal toxicity was found to be similar between the 3D CRT and IMRT patients (61.5% vs 61.2%, respectively) but more treatment breaks were needed (3 vs 0, respectively). The median serum creatinine from before radiotherapy to most recent creatinine was unchanged in the IMRT group (0.80 mg/dL) but increased in the 3D CRT group from 0.80 mg/dL to 1.0 mg/dL (P=.02). The median kidney mean dose was higher in the IMRT versus the 3D CRT group (13.9 Gy vs 11.1 Gy; P=.05). The median kidney V20 was lower for the IMRT versus the 3D CRT group (17.5% vs 22%; P=.17). The median liver mean dose for IMRT and 3D CRT was 13.6 Gy and 18.6 Gy, respectively (P=.19). The median liver V30 was 16.1% and 28%, respectively (PCancer Society.

Estimate of the damage in organs induced by neutrons in three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Benites R, J. L.; Vega C, H. R.; Uribe, M. del R.

2014-08-01

By means of Monte Carlo methods was considered the damage in the organs, induced by neutrons, of patients with cancer that receive treatment in modality of three-dimensional conformal radiotherapy (3D-CRT) with lineal accelerator Varian Ix. The objective of this work was to estimate the damage probability in radiotherapy patients, starting from the effective dose by neutrons in the organs and tissues out of the treatment region. For that a three-dimensional mannequin of equivalent tissue of 30 x 100 x 30 cm 3 was modeled and spherical cells were distributed to estimate the Kerma in equivalent tissue and the absorbed dose by neutrons. With the absorbed dose the effective dose was calculated using the weighting factors for the organ type and radiation type. With the effective dose and the damage factors, considered in the ICRP 103, was considered the probability of damage induction in organs. (Author)

Design and implementation of a rotational radiotherapy technique for breast cancer treatment and their comparison with 3-D-Crt irradiation technique

International Nuclear Information System (INIS)

Gutierrez M, J. G.; Lopez V, A.; Rivera M, T.; Velazquez T, J. J.; Adame G, C. S.; Rubio N, O.; Chagoya G, A.; Hernandez G, J. C.

2015-10-01

Breast cancer is one of oncological diseases worldwide, as well in Mexico, which causes even more deaths than cervical cancer; this condition is the second death cause in women aged 30-54 years and threatens all socio-economic groups. The treatment is highly dependent on the stage which is detected and based on protocols that include a combination of surgery, chemotherapy and radiotherapy. This paper studies the main irradiation technique for patients with mastectomy, breast full cycle (irradiation of the chest well and supraclavicular nodes) in their mode Three Dimensional - Conformal Radiation Therapy (3-D-Crt), and compared with the Volumetric Modulated Arc Therapy (VMAT) technique proposed in this paper. In both techniques the prescription was 50 Gy divided into 25 fractions. The techniques were applied in three female patients (being an initial study) with disease of the left side, the target volume and organs at risk were delineated by the medical treating radiation oncologist, the planning system used was Eclipse version 10; for quantitative comparison of both plans indexes of homogeneity were used, con formality, the target volume coverage and normal tissue, sub factors and overdosing, the conformation number and coverage quality. They were evaluated and compared the media, maximum and minimum dose of the organs at risk, based on the fact that the coverage of the target volume, dose gradient and dose at risk organs are acceptable (prescription dose greater that 90% coverage, gradient less that 20% and organs at risk in accordance with the Quantec limitations for both versions). (Author)

Dosimetry analysis on radiation-induced acute esophagitis after three-dimensional conformal radiotherapy for non-small cell lung cancer

International Nuclear Information System (INIS)

ZZhu Shuchai; Cui Yanli; Li Juan; Liu Zhikun; Shen Wenbin; Su Jingwei; Wang Yuxiang

2010-01-01

Objective: To analyze the related factors with radiation-induced esophagitis after threedimensional conformal radiotherapy for non-small cell lung cancer (NSCLC), in order to explore the predictors for optimizing the treatment planning of NSCLC. Methods: From Aug 2000 to Dec 2004, 104 NSCLC patients received radiotherapy and were eligible for this study, 45 cases squamous cell carcinoma, 20 cases adenocarcinoma, 33 cases carrying with cancer cells by test and 6 case with no definitive pathologic feature.46 patients were treated with three dimensional conformal radiotherapy (3DCRT), the other 58 patients conventional radiotherapy (CRT) before later-course 3DCRT. All the patients received the prescribed dose between 60-78 Gy and the median dose 66 Gy. The correlation of the variables were evaluated by Spearman relationship analysis. The morbidity of radiation-induced esophagitis was analyzed by X 2 test. The multivariate effect on radiation-induced esophagitis was statistically processed by Logistic regression model. Results: In 104 patients, the morbidity of radiation- induced esophagitis was 46.2%, including 32 cases at grade 1, 15 cases at grade 2, 1 case at grade 3. Univariate analysis showed the maximal and mean dose of esophagus, the volume of esophagus irradiated, the values of V 40 , V 45 , V 50 , V 55 , V 60 , LETT 45 , LETT 50 , LETT 55 , LETT 60 for the esophagus were correlated with radiation-induced esophagitis. Logistic regression model showed that the maximum dose received by the esophagus was the independent factor of ≥ 2 grade radiation-induced esophagitis. Conclusions: The maxmal dose of esophagus received might be the important factor of radiation-induced esophagitis. (authors)

Cardiac avoidance in breast radiotherapy: a comparison of simple shielding techniques with intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Landau, David; Adams, Elizabeth J.; Webb, Steve; Ross, Gillian

2001-01-01

Background and purpose: Adjuvant breast radiotherapy (RT) is now part of the routine care of patients with early breast cancer. However, analysis of the Early Breast Cancer Trialists' Collaborative suggests that patients with the lowest risk of dying of breast cancer are at significant risk of cardiac mortality due to longer relapse-free survival. Patients with a significant amount of heart in the high-dose volume have been shown to be at risk of fatal cardiac events. This study was designed to assess whether conformal planning or intensity-modulated radiotherapy (IMRT) techniques allow reduced cardiac irradiation whilst maintaining full target coverage. Material and methods: Ten patients with early breast cancer were available for computed tomography (CT) planning. Each had at least 1 cm maximum heart depth within the posterior border of conventional tangents. For each patient, plans were generated and compared using dose volume histograms for planning target volume (PTV) and organs at risk. The plans included conventional tangents with and without shielding. The shielding was designed to either completely spare the heart or to shield as much heart as possible without compromising PTV coverage. IMRT plans were also prepared using two- and four-field tangential and six-field arc-like beam arrangements. Results: PTV homogeneity was better for the tangential IMRT techniques. For all patients, cardiac irradiation was reduced by the addition of partial cardiac shielding to conventional tangents, without compromise of PTV coverage. The two- and four-field IMRT techniques also reduced heart doses. The average percentage volume of heart receiving >60% of the prescription dose was 4.4% (range 1.0-7.1%) for conventional tangents, 1.5% (0.2-3.9%) for partial shielding, 2.3% (0.5-4.6%) for the two-field IMRT technique and 2.2% (0.4-5.6%) for the four-field IMRT technique. For patients with larger maximum heart depths the four-field IMRT plan achieved greater heart sparing

Secondary effects of radiotherapy on the orofacial sphere

International Nuclear Information System (INIS)

Guillaume, Nicolas

2012-01-01

The objective of this research is to determine the role of the dental surgeon in the taking into care of patients treated by head and neck radiotherapy. It also aims at giving information to the patient on secondary effects which radiotherapy may induce, and at determining which therapeutic behaviour to adopt to prevent or at least mitigate the appearance of complications. The author first presents some generalities on radiotherapy: presentation of upper aero-digestive tract cancers (surgery, radiotherapy, and chemotherapy), description of the different radiotherapy techniques (external radiotherapy, brachytherapy), discussion of factors influencing local secondary effects of radiotherapy. The second part addresses the specific case of early orofacial secondary effects, discusses their origin, clinic signs and prevention means: cutaneous effect, mucositis, xerostomia, candidiasis, taste disorders, relationship between early local reactions and anti-tumour treatment efficiency. The third part addresses late orofacial secondary effects: cervix sclerosis, limitation of mouth opening, dental effects, periodontal diseases, osteoradionecrosis. The last part discusses the evolution of radiotherapy: intensity modulated conformational radiotherapy, targeted therapeutics [fr

Treatment results of adjuvant radiotherapy and salvage radiotherapy after radical prostatectomy for prostate cancer

International Nuclear Information System (INIS)

Wadasaki, Koichi; Kaneyasu, Yuko; Kenjo, Masahiro; Matsuura, Kanji; Murakami, Yuji; Hashimoto, Yasutoshi; Ito, Katsuhide; Kiriu, Hiroshi; Ito, Atsushi

2007-01-01

The indications for and the efficacy of radiation therapy after radical operation for patients with prostate cancer are not clear. We analyzed the treatment results of adjuvant radiotherapy and salvage radiotherapy after radical prostatectomy. Between September 1997 and November 2004, 57 patients received adjuvant radiotherapy or salvage radiotherapy after radical prostatectomy. Fifteen patients received radiation therapy because of positive margins and/or extracapsular invasion in surgical specimens (adjuvant group). Forty-two patients received radiation therapy because of rising prostate-specific antigen (PSA) during follow-up (salvage group). Radiation therapy was delivered to the fossa of the prostate±seminal vesicles by a three-dimensional (3-D) conformal technique to a total dose of 60-66 Gy (median, 60 Gy). Biochemical control was defined as the maintenance of a PSA level of less than 0.2 ng/ml. The median follow-up period after radiation therapy was 33 months (range, 12-98 months). Three-year biochemical control rates were 87% for the adjuvant group and 61% for the salvage group. For patients in the salvage group treated without hormone therapy, the preradiation PSA value was the most significant factor for the biochemical control rate. The 3-year biochemical control rate was 93% in patients whose preradiation PSA was 0.5 ng/ml or less and 29% in patients whose preradiation PSA was more than 0.5 ng/ml. No severe adverse effects (equal to or more than grade 3) were seen in treated patients. Radiation therapy after radical prostatectomy seemed to be effective for adjuvant therapy and for salvage therapy in patients with a preradiation PSA of 0.5 ng/ml or less. Also, radiation to the fossa of the prostate±seminal vesicles, to a total dose of 60-66 Gy, using a three-dimensional (3-D) conformal technique, seemed to be safe. (author)

Retrospective evaluation of dosimetric quality for prostate carcinomas treated with 3D conformal, intensity modulated and volumetric modulated arc radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Crowe, Scott B [Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland (Australia); Kairn, Tanya [Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland (Australia); Premion, Wesley Medical Centre, Brisbane, Queensland (Australia); Middlebrook, Nigel; Hill, Brendan; Christie, David R H; Knight, Richard T [Premion, Wesley Medical Centre, Brisbane, Queensland (Australia); Kenny, John [Australian Clinical Dosimetry Services, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Victoria (Australia); Langton, Christian M; Trapp, Jamie V [Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland (Australia)

2013-12-15

This study examines and compares the dosimetric quality of radiotherapy treatment plans for prostate carcinoma across a cohort of 163 patients treated across five centres: 83 treated with three-dimensional conformal radiotherapy (3DCRT), 33 treated with intensity modulated radiotherapy (IMRT) and 47 treated with volumetric modulated arc therapy (VMAT). Treatment plan quality was evaluated in terms of target dose homogeneity and organs at risk (OAR), through the use of a set of dose metrics. These included the mean, maximum and minimum doses; the homogeneity and conformity indices for the target volumes; and a selection of dose coverage values that were relevant to each OAR. Statistical significance was evaluated using two-tailed Welch's T-tests. The Monte Carlo DICOM ToolKit software was adapted to permit the evaluation of dose metrics from DICOM data exported from a commercial radiotherapy treatment planning system. The 3DCRT treatment plans offered greater planning target volume dose homogeneity than the other two treatment modalities. The IMRT and VMAT plans offered greater dose reduction in the OAR: with increased compliance with recommended OAR dose constraints, compared to conventional 3DCRT treatments. When compared to each other, IMRT and VMAT did not provide significantly different treatment plan quality for like-sized tumour volumes. This study indicates that IMRT and VMAT have provided similar dosimetric quality, which is superior to the dosimetric quality achieved with 3DCRT.

Indications for quality assurance in conformal radiotherapy in Italy; Indicazioni per l'Assicurazione di Qualita nella radioterapia ad intensita modulata

Energy Technology Data Exchange (ETDEWEB)

Banci Buonamici, F [Servizio Ospedaliero Dipartimentale Fisica Medica, Azienda Ospedaliera Careggi, Firenze (Italy); DE Angelis, C; Rosi, A; Tabocchini, M A [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Roma (Italy); Iotti, C [Radioterapia Oncologica, Arcispedale di Santa Maria Nuova, Reggio Emilia (Italy); Olmi, P [Dipartimento di Radioterapia, Istituto Nazionale per lo studio e la cura dei Tumori, Milano (Italy)

2008-07-01

Intensity-Modulated Radiation Therapy (IMRT) is an advanced and promising technique of external beam irradiation. IMRT is able to conform the dose distribution to the 3D tumour shape also for complex geometries, preserving surrounding normal tissues and reducing the probability of side effects. IMRT is a time consuming and complex technique and its use demands high level quality assurance. It is, therefore, very important to define conditions for its utilization. Professionals of Radiotherapy Centres, with experience in the IMRT use, have constituted a multidisciplinary working group with the aim of developing indications in this field. Purpose of the present document is to highlight relevant aspects of the technique, but also to underline the high complexity of the technique, whose implementation requires extreme attention of the staff of Radiotherapy Centres involved. [Italian] La Radioterapia ad Intensita Modulata (Intensity Modulated Radiation Therapy, IMRT) rappresenta una delle piu avanzate e promettenti tecniche di radioterapia oncologica. La possibilita di adattare la distribuzione della dose terapeutica alla geometria, anche molto complessa, di una massa tumorale consente di salvaguardare in modo ottimale i tessuti sani adiacenti riducendo quindi la probabilita di complicanze. L'IMRT e una tecnica di difficile esecuzione, dispendiosa per tempo impiegato e richiede particolare precisione. E quindi fondamentale cercare di definire in quali situazioni puo essere appropriato il suo impiego. Per questo si e costituito un gruppo di lavoro che ha visto coinvolti, con un approccio multidisciplinare, i Centri Italiani di Radioterapia con maggior esperienza nell'uso di questa tecnica. Questo documento si e posto come obiettivo quello di delineare le peculiarita della tecnica e di evidenziare come la sua elevata complessita esiga il massimo rigore nella sua implementazione.

3-D conformal radiotherapy of localized prostate cancer: A subgroup analysis of rectoscopic findings prior to radiotherapy and acute/late rectal side effects

International Nuclear Information System (INIS)

Goldner, Gregor; Zimmermann, Frank; Feldmann, Horst; Glocker, Stefan; Wachter-Gerstner, Natascha; Geinitz, Hans; Becker, Gerd; Poetzi, Regina; Wambersie, Andre; Bamberg, Michael; Molls, Michael; Wachter, Stefan; Poetter, Richard

2006-01-01

Background and purpose: To identify endoscopic pathological findings prior to radiotherapy and a possible correlation with acute or chronic rectal side effects after three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Patients and methods: Between 03/99 and 07/02, a total of 298 patients, who consented in a voluntary rectoscopy prior to radiotherapy were included into the analysis. Patients were treated with a total dose of either 70 or 74 Gy. Pathological rectoscopic findings like hemorrhoids, polyps or diverticula were documented. Acute and late rectal side effects were scored using the EORTC/RTOG score. Results: The most frequent pathological endosopic findings were hemorrhoids (35%), polyps (24%) and diverticula (13%). Rectal toxicity was mostly low to moderate. Grade 0/1 cumulative acute and late rectal side effects were 82 and 84%, grade 2 were 18 and 17%, respectively. We could not identify any correlation between preexisting pathological findings and rectal side effects by statistical analysis. Conclusions: There is no evidence that prostate cancer patients presenting with endoscopic verified pathological findings in the rectal mucosa at diagnosis are at an increased risk to develop rectal side effects when treated with 3D-CRT of the prostatic region

IMRT and 3D conformal radiotherapy with or without elective nodal irradiation in locally advanced NSCLC: A direct comparison of PET-based treatment planning.

Science.gov (United States)

Fleckenstein, Jochen; Kremp, Katharina; Kremp, Stephanie; Palm, Jan; Rübe, Christian

2016-02-01

The potential of intensity-modulated radiation therapy (IMRT) as opposed to three-dimensional conformal radiotherapy (3D-CRT) is analyzed for two different concepts of fluorodeoxyglucose positron emission tomography (FDG PET)-based target volume delineation in locally advanced non-small cell lung cancer (LA-NSCLC): involved-field radiotherapy (IF-RT) vs. elective nodal irradiation (ENI). Treatment planning was performed for 41 patients with LA-NSCLC, using four different planning approaches (3D-CRT-IF, 3D-CRT-ENI, IMRT-IF, IMRT-ENI). ENI included a boost irradiation after 50 Gy. For each plan, maximum dose escalation was calculated based on prespecified normal tissue constraints. The maximum prescription dose (PD), tumor control probability (TCP), conformal indices (CI), and normal tissue complication probabilities (NTCP) were analyzed. IMRT resulted in statistically significant higher prescription doses for both target volume concepts as compared with 3D-CRT (ENI: 68.4 vs. 60.9 Gy, p ENI, there was a considerable theoretical increase in TCP (IMRT: 27.3 vs. 17.7 %, p ENI: 12.3 vs. 30.9 % p < 0.0001; IF: 15.9 vs. 24.1 %; p < 0.001). The IMRT technique and IF target volume delineation allow a significant dose escalation and an increase in TCP. IMRT results in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels.

NMR and modelling techniques in structural and conformation analysis

Energy Technology Data Exchange (ETDEWEB)

Abraham, R J [Liverpool Univ. (United Kingdom)

1994-12-31

The use of Lanthanide Induced Shifts (L.I.S.) and modelling techniques in conformational analysis is presented. The use of Co{sup III} porphyrins as shift reagents is discussed, with examples of their use in the conformational analysis of some heterocyclic amines. (author) 13 refs., 9 figs.

Improvement in toxicity in high risk prostate cancer patients treated with image-guided intensity-modulated radiotherapy compared to 3D conformal radiotherapy without daily image guidance

International Nuclear Information System (INIS)

Sveistrup, Joen; Rosenschöld, Per Munck af; Deasy, Joseph O; Oh, Jung Hun; Pommer, Tobias; Petersen, Peter Meidahl; Engelholm, Svend Aage

2014-01-01

Image-guided radiotherapy (IGRT) facilitates the delivery of a very precise radiation dose. In this study we compare the toxicity and biochemical progression-free survival between patients treated with daily image-guided intensity-modulated radiotherapy (IG-IMRT) and 3D conformal radiotherapy (3DCRT) without daily image guidance for high risk prostate cancer (PCa). A total of 503 high risk PCa patients treated with radiotherapy (RT) and endocrine treatment between 2000 and 2010 were retrospectively reviewed. 115 patients were treated with 3DCRT, and 388 patients were treated with IG-IMRT. 3DCRT patients were treated to 76 Gy and without daily image guidance and with 1–2 cm PTV margins. IG-IMRT patients were treated to 78 Gy based on daily image guidance of fiducial markers, and the PTV margins were 5–7 mm. Furthermore, the dose-volume constraints to both the rectum and bladder were changed with the introduction of IG-IMRT. The 2-year actuarial likelihood of developing grade > = 2 GI toxicity following RT was 57.3% in 3DCRT patients and 5.8% in IG-IMRT patients (p < 0.001). For GU toxicity the numbers were 41.8% and 29.7%, respectively (p = 0.011). On multivariate analysis, 3DCRT was associated with a significantly increased risk of developing grade > = 2 GI toxicity compared to IG-IMRT (p < 0.001, HR = 11.59 [CI: 6.67-20.14]). 3DCRT was also associated with an increased risk of developing GU toxicity compared to IG-IMRT. The 3-year actuarial biochemical progression-free survival probability was 86.0% for 3DCRT and 90.3% for IG-IMRT (p = 0.386). On multivariate analysis there was no difference in biochemical progression-free survival between 3DCRT and IG-IMRT. The difference in toxicity can be attributed to the combination of the IMRT technique with reduced dose to organs-at-risk, daily image guidance and margin reduction

Stereotactic body radiotherapy for lung cancer: how much does it really cost?

Science.gov (United States)

Lievens, Yolande; Obyn, Caroline; Mertens, Anne-Sophie; Van Halewyck, Dries; Hulstaert, Frank

2015-03-01

Despite the lack of randomized evidence, stereotactic body radiotherapy (SBRT) is being accepted as superior to conventional radiotherapy for patients with T1-2N0 non-small-cell lung cancer in the periphery of the lung and unfit or unwilling to undergo surgery. To introduce SBRT in a system of coverage with evidence development, a correct financing had to be determined. A time-driven activity-based costing model for radiotherapy was developed. Resource cost calculation of all radiotherapy treatments, standard and innovative, was conducted in 10 Belgian radiotherapy centers in the second half of 2012. The average cost of lung SBRT across the 10 centers (6221&OV0556;) is in the range of the average costs of standard fractionated 3D-conformal radiotherapy (5919&OV0556;) and intensity-modulated radiotherapy (7379&OV0556;) for lung cancer. Hypofractionated 3D-conformal radiotherapy and intensity-modulated radiotherapy schemes are less costly (3993&OV0556; respectively 4730&OV0556;). The SBRT cost increases with the number of fractions and is highly dependent of personnel and equipment use. SBRT cost varies more by centre than conventional radiotherapy cost, reflecting different technologies, stages in the learning curve and a lack of clear guidance in this field. Time-driven activity-based costing of radiotherapy is feasible in a multicentre setup, resulting in real-life resource costs that can form the basis for correct reimbursement schemes, supporting an early yet controlled introduction of innovative radiotherapy techniques in clinical practice.

Postoperative radiotherapy for prostate cancer. Morbidity of local-only or local-plus-pelvic radiotherapy

International Nuclear Information System (INIS)

Waldstein, Cora; Poetter, Richard; Widder, Joachim; Goldner, Gregor; Doerr, Wolfgang

2018-01-01

The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer. Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups. For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5-year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5-year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%. Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4-field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects. (orig.) [de

Dosimetric comparison of the related parameters between simultaneous integrated boost intensity-modulated radiotherapy and sequential boost conformal radiotherapy for postoperative malignant glioma of the brain

International Nuclear Information System (INIS)

Shao Qian; Lu Jie; Li Jianbin; Sun Tao; Bai Tong; Liu Tonghai; Yin Yong

2011-01-01

Objective: To compare the dosimetric of different parameter of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) with sequential boost conformal radiotherapy (SB-CRT) for postoperative malignant glioma of the brain. Methods: Ten patients with malignant glioma of brain were selected to study. Each patient was simulated all by CT and MRI, and the imagings of CT and MRI were all sent to Pinnacle 3 planning system. The fusion technology with MR-CT imaging was used on Pinnacle 3 planning system. The target volume was delineated and defined based on MRI. The postoperative residual lesion and resection cavity were defined as gross tumor volume (GTV) and expanded GTV some scope was defined as clinical target volume (CTV). The margins of GTV expanded 10 mm and 25 mm were defined as CTV1 and CTV2 respectively. CTV1 and CTV2 all enlarged 5 mm were defined as PTV1 and PTV2 respectively. The plans of simultaneous integrated boost intensity-modulated radiotherapy and sequential boost conformal radiotherapy were respectively designed for each patient using Pinnacle 3 planning system and the dosimetric of different parameter was compared. The prescribe dose of SIB-IMRT was PTV1: 62.5 Gy/25 f, PTV2: 50.0 Gy/25 f; and SB-CRT was PTV1: 66.0 Gy/33 f, PTV2: 50.0 Gy/25 f. The dosimetries of different parameters of SIB-IMRT and SB-CRT were compared by using Paired-Samples T Test. Results: The maximum and mean dose of PTV1, PTV2, and brainstem were of significant difference (P 0.05). Conclusion: The SIB-IMRT plan is better than the SB-CRT plan. The CI and HI of SIB-IMRT are superior to SB-CRT. At the same time, it can preserve the important organs such as brainstem and reduce the mean dose of whole brain. On the other hand it can shorten the total period of therapy time. (authors)

Dosimetric comparison between intensity-modulated with coplanar field and 3D conformal radiotherapy with noncoplanar field for postocular invasion tumor.

Science.gov (United States)

Wenyong, Tu; Lu, Liu; Jun, Zeng; Weidong, Yin; Yun, Li

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 degrees , 30-45 degrees , 240-270 degrees , and 310-335 degrees degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D(max) and D(min) dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed. 2010 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Dosimetric Comparison Between Intensity-Modulated with Coplanar Field and 3D Conformal Radiotherapy with Noncoplanar Field for Postocular Invasion Tumor

International Nuclear Information System (INIS)

Tu Wenyong; Liu Lu; Zeng Jun; Yin Weidong; Li Yun

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 deg., 30-45 deg., 240-270 deg., and 310-335 deg. degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D max and D min dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p < 0.001). Physical endpoints for target showed the mean target dose to be low in the CF IMRT plan, caused by a large target dose in homogeneity (p < 0.001). The impact of NCF 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed.

A neurosurgery/stereotactic radiotherapy dedicated PACS for conformal radiotherapy

International Nuclear Information System (INIS)

Lefkopoulos, D.; Bocquiault, P.; Levrier, M.; Merienne, L.; Schlienger, M.

1995-01-01

To realise conformal cerebral stereotactic irradiations we use a Neurosurgery/stereotactic dedicated PACS between two distant hospitals. It connects the stereotactic neurosurgery planification imaging system NEUROAXIS (Sopelem-Sofretec/Ste Anne Hospital) with the dosimetric TPS ARTEMIS-3D/Dosigray (Tenon Hospital). NEUROAXIS is a computer aided stereotactic biopsies and stereo-electroencephalographies, used by surgeons in operating room. The system determines the precise location data for Talairach radiological equipment (X ray source at 5 meters from film) and the geometry of scanner and MRI stereotactical referentials. It provides a full set of features for lesion localization, geometrical computations, surgical planifications, picture archiving, stereotactic angiography, CT and MRI image processing and networking. It sends images through the French public digital network ISDN (NUMERIS/France Telecom : 2x64 Kbits/s) from Ste Anne to Tenon Hospital. Stereotactic angiographic and CT images are reformatted into the DOSIGRAY image processing environment where 3-D dose distributions, displays and DVHs are computed to determine the optimal treatment. ARTEMIS-3D/Dosigray is a TPS for stereotactic radiotherapy devised by the Tenon Hospital for clinical methodology and 3D dose calculations, optimization software development and the Dosigray company for multimodality imaging, (2D(3D)) computer graphics for dose and anatomical representation and data networking. Communication within the radiation oncology department is provided by local area ETHERNET network, linking heterogeneous systems (Vaxstations-3200; Decstation (5000(240))) by means of different protocols. The works in progress are to send back via the same network the 3-D dose matrix to Neurosurgery department NEUROAXIS system. Our PACS is used since six months to treat patients. It has permitted to improve the treatment quality in comparison with our first version TPS ARTEMIS-3D

Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

International Nuclear Information System (INIS)

Chan, Philip; Yeo, Inhwan; Perkins, Gregory; Fyles, Anthony; Milosevic, Michael

2006-01-01

To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. The median planning target volume (PTV) was 151 cm 3 (range 58–512 cm 3 ). The median overlap of the contoured rectum with the PTV was 15 (1–56) %, and 11 (4–35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study

Investigation of normal tissue complication probabilities in prostate and partial breast irradiation radiotherapy techniques

International Nuclear Information System (INIS)

Bezak, E.; Takam, R.; Bensaleh, S.; Yeoh, E.; Marcu, L.

2011-01-01

Full text: Normal- Tissue-Complication Probabilities of rectum, bladder and urethra following various radiation techniques for prostate cancer were evaluated using the relative-seriality and Lyman models. NTCPs of lungs, heart and skin, their dependence on sourceposition, balloon-deformation were also investigated for HDR mammosite brachytherapy. The prostate treatment techniques included external three dimentional conformal-radiotherapy, Low-Dose-Rate brachytherapy (1-125), High-Dose-Rate brachytherapy (Ir-I92). Dose- Volume-Histograms of critical structures for prostate and breast radiotherapy, retrieved from corresponding treatment planning systems, were converted to Biological Effective Dose (BEffD)-based and Equivalent Dose(Deq)-based DVHs to account for differences in radiation delivery and fractionation schedule. Literature-based model parameters were used to calculate NTCPs. Hypofractionated 3D-CRT (2.75 Gy/fraction, total dose 55 Gy) NTCPs of rectum, bladder and urethra were less than those for standard fractionated 4-field 3D-CRT (2-Gy/fraction, 64 Gy) and dose-escalated 4- and 5-field 3D-CRT (74 Gy). Rectal and bladder NTCPs (5.2% and 6.6%) following the dose-escalated 4-field 3D-CRT (74 Gy) were the highest among analyzed techniques. The average NTCP for rectum and urethra were 0.6% and 24.7% for LDRBT and 0.5% and 11.2% for HDR-BT. For Mammosite, NTCP was estimated to be 0.1 %, 0.1 %, 1.2% and 3.5% for skin desquamation, erythema, telangiectasia and fibrosis respectively (the source positioned at the balloon centre). A 4 mm Mammosite-balloon deformation leads to overdosing of PTV regions by ∼40%, resulting in excessive skin dose and increased NTCP. Conclusions Prostate brachytherapy resulted in NTCPs lower compared to external beam techniques. Mammosite-brachytherapy resulted in no heart/lung complications regardless of balloon deformation. However, 4 mm deformation caused 0.6% increase in tissue fibrosis NTCP.

A deterministic iterative least-squares algorithm for beam weight optimization in conformal radiotherapy

International Nuclear Information System (INIS)

Chen Yan; Michalski, Darek; Houser, Christopher; Galvin, James M.

2002-01-01

Currently, inverse treatment planning in conformal radiotherapy is, in part, a trial-and-error process due to the interplay of many competing criteria for obtaining a clinically acceptable dose distribution. A new method is developed for beam weight optimization that incorporates clinically relevant nonlinear and linear constraints. The process is driven by a nonlinear, quasi-quadratic objective function and the solution space is defined by a set of linear constraints. At each step of iteration, the optimization problem is linearized by a self-consistent approximation that is local to the existing dose distribution. The dose distribution is then improved by solving a series of constrained least-squares problems using an established method until all prescribed constraints are satisfied. This differs from the current approaches in that it does not rely on the search for the global minimum of a specific objective function. Essentially, our proposed objective function can be construed as a functional that comprises a class of dose-based quadratic objective functions. Empirical adjustment for appropriate model parameters in the construction of objective function is minimized, since these parameters are in effect adaptively adjusted during optimization. The method is robust in solving difficult clinical cases using either aperture or pencil beam based planning techniques for intensity-modulated radiation therapy. (author)

Limited Advantages of Intensity-Modulated Radiotherapy Over 3D Conformal Radiation Therapy in the Adjuvant Management of Gastric Cancer

International Nuclear Information System (INIS)

Alani, Shlomo; Soyfer, Viacheslav; Strauss, Natan; Schifter, Dan; Corn, Benjamin W.

2009-01-01

Purpose: Although chemoradiotherapy was considered the standard adjuvant treatment for gastric cancer, a recent Phase III trial (Medical Research Council Adjuvant Gastric Infusional Chemotherapy [MAGIC]) did not include radiotherapy in the randomization scheme because it was considered expendable. Given radiotherapy's potential, efforts needed to be made to optimize its use for treating gastric cancer. We assessed whether intensity-modulated radiotherapy (IMRT) could improve upon our published results in patients treated with three-dimensional (3D) conformal therapy. Methods and Materials: Fourteen patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a noncoplanar four-field arrangement. Subsequently, a nine-field IMRT plan was designed using a CMS Xio IMRT version 4.3.3 module. Two IMRT beam arrangements were evaluated: beam arrangement 1 consisted of gantry angles of 0 deg., 53 deg., 107 deg., 158 deg., 204 deg., 255 deg., and 306 deg.. Beam arrangement 2 consisted of gantry angles of 30 deg., 90 deg., 315 deg., and 345 deg.; a gantry angle of 320 deg./couch, 30 deg.; and a gantry angle of 35 o /couch, 312 o . Both the target volume coverage and the dose deposition in adjacent critical organs were assessed in the plans. Dose-volume histograms were generated for the clinical target volume, kidneys, spine, and liver. Results: Comparison of the clinical target volumes revealed satisfactory coverage by the 95% isodose envelope using either IMRT or 3D conformal therapy. However, IMRT was only marginally better than 3D conformal therapy at protecting the spine and kidneys from radiation. Conclusions: IMRT confers only a marginal benefit in the adjuvant treatment of gastric cancer and should be used only in the small subset of patients with risk factors for kidney disease or those with a preexisting nephropathy.

Limited advantages of intensity-modulated radiotherapy over 3D conformal radiation therapy in the adjuvant management of gastric cancer.

Science.gov (United States)

Alani, Shlomo; Soyfer, Viacheslav; Strauss, Natan; Schifter, Dan; Corn, Benjamin W

2009-06-01

Although chemoradiotherapy was considered the standard adjuvant treatment for gastric cancer, a recent Phase III trial (Medical Research Council Adjuvant Gastric Infusional Chemotherapy [MAGIC]) did not include radiotherapy in the randomization scheme because it was considered expendable. Given radiotherapy's potential, efforts needed to be made to optimize its use for treating gastric cancer. We assessed whether intensity-modulated radiotherapy (IMRT) could improve upon our published results in patients treated with three-dimensional (3D) conformal therapy. Fourteen patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a noncoplanar four-field arrangement. Subsequently, a nine-field IMRT plan was designed using a CMS Xio IMRT version 4.3.3 module. Two IMRT beam arrangements were evaluated: beam arrangement 1 consisted of gantry angles of 0 degrees , 53 degrees , 107 degrees , 158 degrees , 204 degrees , 255 degrees , and 306 degrees . Beam arrangement 2 consisted of gantry angles of 30 degrees , 90 degrees , 315 degrees , and 345 degrees ; a gantry angle of 320 degrees /couch, 30 degrees ; and a gantry angle of 35 degrees /couch, 312 degrees . Both the target volume coverage and the dose deposition in adjacent critical organs were assessed in the plans. Dose-volume histograms were generated for the clinical target volume, kidneys, spine, and liver. Comparison of the clinical target volumes revealed satisfactory coverage by the 95% isodose envelope using either IMRT or 3D conformal therapy. However, IMRT was only marginally better than 3D conformal therapy at protecting the spine and kidneys from radiation. IMRT confers only a marginal benefit in the adjuvant treatment of gastric cancer and should be used only in the small subset of patients with risk factors for kidney disease or those with a preexisting nephropathy.

Three-Dimensional Non-Coplanar Conformal Radiotherapy Yields Better Results Than Traditional Beam Arrangements for Adjuvant Treatment of Gastric Cancer

International Nuclear Information System (INIS)

Soyfer, Viacheslav; Corn, Benjamin W.; Melamud, Alex B.S.; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

2007-01-01

Purpose: The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. Methods and Materials: A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field 'box' was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. Results: The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Conclusion: Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical

Three-dimensional non-coplanar conformal radiotherapy yields better results than traditional beam arrangements for adjuvant treatment of gastric cancer.

Science.gov (United States)

Soyfer, Viacheslav; Corn, Benjamin W; Melamud, Alex; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

2007-10-01

The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field "box" was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical practice.

Dosimetric comparison of standard bi-dimensional radiotherapy, mono-isocentric three-dimensional and arc-therapy for a bilateral breast cancer case with ganglionary attack; Comparaison dosimetrique pour un cas de cancer du sein bilateral avec atteinte ganglionnaire de la radiotherapie bidimensionnelle standard, la radiotherapie tridimensionnelle mono-isocentrique et l'arctherapie

Energy Technology Data Exchange (ETDEWEB)

Arnaud, A. [Centre Leon-Berard, Lyon (France); Bodez, V.; Alric, K.; Chastel, D.; Mege, A. [Institut Sainte-Catherine, Avignon (France)

2011-10-15

The authors report a study which aimed at determining the optimal radiotherapy technique for a patient operated from a bilateral breast cancer with ganglionary attack and peculiar thoracic conformation. A dosimetric study has been performed. Target volumes and lung and heart coverages have been compared for three techniques: bi-dimensional and three-dimensional radiotherapy, and arc-therapy. It appears that arc-therapy would allow a dosimetric and therapeutic duration gain without improving the target volume coverage while increasing doses delivered to organs at risk. Short communication

A FAST MORPHING-BASED INTERPOLATION FOR MEDICAL IMAGES: APPLICATION TO CONFORMAL RADIOTHERAPY

Directory of Open Access Journals (Sweden)

Hussein Atoui

2011-05-01

Full Text Available A method is presented for fast interpolation between medical images. The method is intended for both slice and projective interpolation. It allows offline interpolation between neighboring slices in tomographic data. Spatial correspondence between adjacent images is established using a block matching algorithm. Interpolation of image intensities is then carried out by morphing between the images. The morphing-based method is compared to standard linear interpolation, block-matching-based interpolation and registrationbased interpolation in 3D tomographic data sets. Results show that the proposed method scored similar performance in comparison to registration-based interpolation, and significantly outperforms both linear and block-matching-based interpolation. This method is applied in the context of conformal radiotherapy for online projective interpolation between Digitally Reconstructed Radiographs (DRRs.

Dosimetric and clinical results of three-dimensional conformal radiotherapy for locally recurrent nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Zheng Xiaokang; Ma Jun; Chen Longhua; Xia Yunfei; Shi Yusheng

2005-01-01

Purpose: To assess the dosimetric and clinical results of three-dimensional conformal radiotherapy (3D CRT) for locally recurrent nasopharyngeal carcinoma (NPC). Methods: A total of 86 patients with locally recurrent NPC were retreated with 3D CRT. The median prescribed dose was 68 Gy with 2 Gy per fractionation. Dosimetric quality was evaluated with dose distribution in planning target volume (PTV) and specified organs at risk (OAR), dose conformity index (CI) and dose homogeneity index (HI). The actuarial rate of local failure-free (LFF), overall survival (OS) and major late toxicities (MLT) were estimated with Kaplan-Meier method. Multivariate analysis for prognosis was performed using the Cox regression proportional hazards model. Results: The mean dose to PTV averaged 66.8 Gy, and the dose to specified OAR was acceptable. The average value of CI and HI was 0.59 and 9.1%. The 5-year actuarial rate of LFF and OS was 71 and 40%, respectively. The 5-year actuarial incidence of MLT≥Grade 3 and ≥Grade 4 were 100 and 49%, respectively. The major prognostic factors were T stage and the size of gross tumor volume (GTV). Advanced T stage and large GTV volume were associated with poor LFF and OS and high risk of MLT. Conclusion: The dosimetric quality of 3D CRT for locally recurrent NPC is generally excellent. A relatively high local control was achieved with this technique. However, the incidence of late toxicities were not found to decrease as originally expected. Early diagnosis of the recurrence and reasonable definition of the target volume are crucial to achieve a better outcome

A comparison of different three-dimensional treatment planning techniques for localized radiotherapy of prostate cancer

International Nuclear Information System (INIS)

Koswig, S.; Dinges, S.; Buchali, A.; Boehmer, D.; Salk, J.; Rosenthal, P.; Harder, C.; Schlenger, L.; Budach, V.

1999-01-01

Purpose: Four different three-dimensional planning techniques for localized radiotherapy of prostate cancer were compared with regard to dose homogeneity within the target volume and dose to organs at risk, dependent upon tumor stage. Patients and Methods: Six patients with stage T1, 7 patients with stage T2 and 4 patients with stage T3 were included in this study. Four different 3D treatment plans (rotation, 4-field, 5-field and 6-field technique) were calculated for each patient. Dose was calculated with the reference point at the isocenter (100%). The planning target volume was encompassed within the 95% isodose surface. All the techniques used different shaped portal for each beam. Dose volume histograms were created and compared for the planning target volume and the organs at risk (33%, 50%, 66% volume level) in all techniques. Results: The 4 different three-dimensional planning techniques revealed no differences concerning dose homogeneity within the planning target volume. The dose volume distribution at organs at risk show differences between the calculated techniques. In our study the best protection for bladder and rectum in stage T1 and T2 was achieved by the 6-field technique. A significant difference was achieved between 6-field and 4-field technique only in the 50% volume of the bladder (p=0.034), between the 6-field and rotation technique (all volume levels) and between 5-field and rotation technique (all volume levels). In stage T1, T2 6-field and 4-field technique in 50% (p-0.033) and 66% (p=0.011) of the rectum volume. In stage T3 a significant difference was not observed between the 4 techniques. The best protection of head of the femur was achieved by the rotation technique. Conclusion: In the localized radiotherapy of prostate cancer in stage T1 or T2 the best protection for bladder and rectum was achieved by a 3D-planned conformal 6-field technique. If the seminal vesicles have been included in the target volume and in the case of large

Evaluation of a mixed beam therapy for post-mastectomy breast cancer patients: bolus electron conformal therapy combined with intensity modulated photon radiotherapy and volumetric modulated photon arc therapy.

Science.gov (United States)

Zhang, Rui; Heins, David; Sanders, Mary; Guo, Beibei; Hogstrom, Kenneth

2018-05-10

The purpose of this study was to assess the potential benefits and limitations of a mixed beam therapy, which combined bolus electron conformal therapy (BECT) with intensity modulated photon radiotherapy (IMRT) and volumetric modulated photon arc therapy (VMAT), for left-sided post-mastectomy breast cancer patients. Mixed beam treatment plans were produced for nine post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic with VMAT alone. The mixed beam plans consisted of 40 Gy to the chest wall area using BECT, 40 Gy to the supraclavicular area using parallel opposed IMRT, and 10 Gy to the total planning target volume (PTV) by optimizing VMAT on top of the BECT+IMRT dose distribution. The treatment plans were created in a commercial treatment planning system (TPS), and all plans were evaluated based on PTV coverage, dose homogeneity index (DHI), conformity index (CI), dose to organs at risk (OARs), normal tissue complication probability (NTCP), and secondary cancer complication probability (SCCP). The standard VMAT alone planning technique was used as the reference for comparison. Both techniques produced clinically acceptable PMRT plans but with a few significant differences: VMAT showed significantly better CI (0.70 vs. 0.53, p 0.5 cm and volume of tissue between the distal PTV surface and heart or lung approximately > 250 cm 3 ) between distal PTV surface and lung may benefit the most from mixed beam therapy. This work has demonstrated that mixed beam therapy (BECT+IMRT : VMAT = 4 : 1) produces clinically acceptable plans having reduced OAR doses and risks of side effects compared with VMAT. Even though VMAT alone produces more homogenous and conformal dose distributions, mixed beam therapy remains as a viable option for treating post-mastectomy patients, possibly leading to reduced normal tissue complications. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Emerging radiotherapy technology in a developing country: A single Brazilian institution assessment of stereotactic body radiotherapy application

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Moraes, Fabio Ynoe; Bonifacio, Lorine Arias; Neves-Junior, Wellington Pimenta; Hanna, Samir Abdallah; Abreu, Carlos Eduardo Cintra Vita; Arruda, Fernando Freire; Silva, Joao Luis Fernandes; Carvalho, Heloisa Andrade, E-mail: fymoraes@gmail.com [Hospital Sirio-Libanes, Sao Paulo, SP(Brazil)

2016-11-15

Objective: To provide a quantitative profile of the indications and use of stereotactic body radiotherapy (SBRT) in a developing country oncology-based institution. In addition, to describe the patient and treatment characteristics, and to provide a temporal analysis. Method: SBRT patients treated from 2007 to 2015 were retrospectively evaluated by two independently investigators. Data were stratified and compared in two periods: first experience (FE) (May 2007 to April 2011), and following experience (FollowE) (May 2011 to April 2015). The following parameters were compared between the groups: total number of treated patients and lesions, treatment site, additional image fusion used, formal protocol adoption, and SBRT planning technique. Results: One hundred and seventy-six (176) patients with 191 lesions were treated: 34 (18%) lesions in the FE and 157 (82%) lesions in FollowE. The majority of lesions were metastases (60.3%), and lung (60.2%) was the most common treatment site, followed by spine (31%), and others (8.8%). An average of 1.4 (±0.6) additional imaging exams for delineation was performed. Conformal 3D radiotherapy planning technique was used in 64.4%, and intensity modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT) in the remaining 35.6% (p=0.0001). Higher rates of curative treatments were observed in FE, as well as more lung lesions, patients ≥ 70 years, 3D conformal, number of additional images and ECOG 0, and all presented p<0.05. The global rate of protocol statement was 79%, lung treatment being the most stated. Conclusion: SBRT application is rapidly increasing in our setting. Treatment sites and planning techniques are becoming more diversified and complex. (author)

Conformal techniques for OPE in asymptotically free quantum field theory

International Nuclear Information System (INIS)

Craigie, N.S.; Dobrev, V.K.

1982-06-01

We discuss the relationship between the short-distance behaviour of vertex functions and conformal invariance in asymptotically free theories. We show how conformal group techniques can be used to derive spectral representations of wave functions and vertex functions in QCD. (author)

Toxicity and dosimetric analysis of non-small cell lung cancer patients undergoing radiotherapy with 4DCT and image-guided intensity modulated radiotherapy: a regional centre's experience.

Science.gov (United States)

Livingston, Gareth C; Last, Andrew J; Shakespeare, Thomas P; Dwyer, Patrick M; Westhuyzen, Justin; McKay, Michael J; Connors, Lisa; Leader, Stephanie; Greenham, Stuart

2016-09-01

For patients receiving radiotherapy for locally advance non-small cell lung cancer (NSCLC), the probability of experiencing severe radiation pneumonitis (RP) appears to rise with an increase in radiation received by the lungs. Intensity modulated radiotherapy (IMRT) provides the ability to reduce planned doses to healthy organs at risk (OAR) and can potentially reduce treatment-related side effects. This study reports toxicity outcomes and provides a dosimetric comparison with three-dimensional conformal radiotherapy (3DCRT). Thirty curative NSCLC patients received radiotherapy using four-dimensional computed tomography and five-field IMRT. All were assessed for early and late toxicity using common terminology criteria for adverse events. All plans were subsequently re-planned using 3DCRT to the same standard as the clinical plans. Dosimetric parameters for lungs, oesophagus, heart and conformity were recorded for comparison between the two techniques. IMRT plans achieved improved high-dose conformity and reduced OAR doses including lung volumes irradiated to 5-20 Gy. One case each of oesophagitis and erythema (3%) were the only Grade 3 toxicities. Rates of Grade 2 oesophagitis were 40%. No cases of Grade 3 RP were recorded and Grade 2 RP rates were as low as 3%. IMRT provides a dosimetric benefit when compared to 3DCRT. While the clinical benefit appears to increase with increasing target size and increasing complexity, IMRT appears preferential to 3DCRT in the treatment of NSCLC.

Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT

International Nuclear Information System (INIS)

Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

2011-01-01

This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

New Language and Old Problems in Breast Cancer Radiotherapy.

Science.gov (United States)

Chiricuţă, Ion Christian

2017-01-01

New developments in breast cancer radiotherapy make possible new standards in treatment recommandations based on international guidelines. Developments in radiotherapy irradiation techniques from 2D to 3D-Conformal RT and to IMRT (Intensity Modulated Arc Therapy) make possible to reduce the usual side effects on the organs at risk as: skin, lung, miocard, bone, esophagus and brahial plexus. Dispite of all these progresses acute and late side effects are present. Side effects are as old as the radiotherapy was used. New solutions are available now by improving irradiation techniques. New techniques as sentinel node procedure (SNP) or partial breast irradiation (PBRT) and immediate breast reconstruction with silicon implants (IBRIS) make necessary new considerations regarding the target volume delineations. A new language for definition of gross tumor volume (GTV), clinical target volume (CTV) based on the new diagnostic methods as PET/CT,nonaparticle MRI will have real impact on target delineation and irradiation techniques. "The new common language in breast cancer therapy" would be the first step to improve the endresults and finally the quality of life of the patients. Celsius.

A Comparison of Helical Intensity-Modulated Radiotherapy, Intensity-Modulated Radiotherapy, and 3D-Conformal Radiation Therapy for Pancreatic Cancer

International Nuclear Information System (INIS)

Poppe, Matthew M.; Narra, Venkat; Yue, Ning J.; Zhou Jinghao; Nelson, Carl; Jabbour, Salma K.

2011-01-01

We assessed dosimetric differences in pancreatic cancer radiotherapy via helical intensity-modulated radiotherapy (HIMRT), linac-based IMRT, and 3D-conformal radiation therapy (3D-CRT) with regard to successful plan acceptance and dose to critical organs. Dosimetric analysis was performed in 16 pancreatic cases that were planned to 54 Gy; both post-pancreaticoduodenectomy (n = 8) and unresected (n = 8) cases were compared. Without volume modification, plans met constraints 75% of the time with HIMRT and IMRT and 13% with 3D-CRT. There was no statistically significantly improvement with HIMRT over conventional IMRT in reducing liver V35, stomach V45, or bowel V45. HIMRT offers improved planning target volume (PTV) dose homogeneity compared with IMRT, averaging a lower maximum dose and higher volume receiving the prescription dose (D100). HIMRT showed an increased mean dose over IMRT to bowel and liver. Both HIMRT and IMRT offer a statistically significant improvement over 3D-CRT in lowering dose to liver, stomach, and bowel. The results were similar for both unresected and resected patients. In pancreatic cancer, HIMRT offers improved dose homogeneity over conventional IMRT and several significant benefits to 3D-CRT. Factors to consider before incorporating IMRT into pancreatic cancer therapy are respiratory motion, dose inhomogeneity, and mean dose.

Special set-up and treatment techniques for the radiotherapy of pediatric malignancies

International Nuclear Information System (INIS)

Martinez, A.; Donaldson, S.S.; Bagshaw, M.A.

1977-01-01

The prevention of serious and long term complications of treatment have become as important a consideration in the therapy of children with malignant disease as the goal of tumor control. This balance requires meticulous treatment planning and attention to the treatment preparation and immobilization techniques when radiotherapy is administered to children. Accurate localization of tumor volume and daily reproducibility is essential for delivering precise irradiation. Four special set-up and treatment techniques which have a specific usefulness in radiotherapy for pediatric malignancies are defined and illustrated with the aid of clinical cases. They include the three point set-up, the split beam technique, the isocentric technique, and the strinking field technique

Three-dimensional conformal pancreas treatment: comparison of four- to six-field techniques

International Nuclear Information System (INIS)

Higgins, Patrick D.; Sohn, Jason W.; Fine, Robert M.; Schell, Michael C.

1995-01-01

Purpose: We compare practical conformal treatment approaches to pancreatic cancer using 6 and 18 MV photons and contrast those approaches against standard techniques. Methods and Materials: A four-field conformal technique for treating pancreas cancer has been developed using nonopposed 18 MV photons. This approach has been extended to 6 MV photon application by the addition of one to two fields. These techniques have been optimized to increase sparing of normal liver and bowel, compared with opposed-field methods, to improve patient tolerance of high doses. In this study we compare these techniques in a simulated tumor model in a cylindrical phantom. Dose-volume analysis is used to quantify differences between the conformal, nonopposed techniques with conformal, opposed field methods. This model is also used to evaluate the effect of 1-2 cm setup errors on dose-volume coverage. Results: Dose-volume analysis demonstrates that five-to-six field conformal treatments using 6 MV photons provides similar or better dose coverage and normal tissue sparing characteristics as an optimized 18 MV, four-field approach when 1-2 cm margins are included for setup uncertainty. All approaches using nonopposed beam geometry provide significant reduction in the volume of tissue encompassed by the 30-50% isodose surfaces, as compared with four-field box techniques. Conclusions: Three-dimensional (3D) conformal treatments can be designed that significantly improve dose-volume characteristics over conventional treatment designs without costing unacceptable amounts of machine time. Further, deep intraabdominal sites can be adequately accessed and treated on intermediate energy machines with a relatively moderate increase in machine time

External validation of three dimensional conformal radiotherapy based NTCP models for patient-rated xerostomia and sticky saliva among patients treated with intensity modulated radiotherapy

International Nuclear Information System (INIS)

Beetz, Ivo; Schilstra, Cornelis; Luijk, Peter van; Christianen, Miranda E.M.C.; Doornaert, Patricia; Bijl, Henk P.; Chouvalova, Olga; Heuvel, Edwin R. van den; Steenbakkers, Roel J.H.M.; Langendijk, Johannes A.

2012-01-01

Purpose: The purpose of this study was to investigate the ability of predictive models for patient-rated xerostomia (XER 6M ) and sticky saliva (STIC 6M ) at 6 months after completion of primary (chemo)radiation developed in head and neck cancer patients treated with 3D-conformal radiotherapy (3D-CRT) to predict outcome in patients treated with intensity modulated radiotherapy (IMRT). Methods and materials: Recently, we published the results of a prospective study on predictive models for patient-rated xerostomia and sticky saliva in head and neck cancer patients treated with 3D-CRT (3D-CRT based NTCP models). The 3D-CRT based model for XER 6M consisted of three factors, including the mean parotid dose, age, and baseline xerostomia (none versus a bit). The 3D-CRT based model for STIC 6M consisted of the mean submandibular dose, age, the mean sublingual dose, and baseline sticky saliva (none versus a bit). In the current study, a population consisting of 162 patients treated with IMRT was used to test the external validity of these 3D-CRT based models. External validity was described by the explained variation (R 2 Nagelkerke) and the Brier score. The discriminative abilities of the models were calculated using the area under the receiver operating curve (AUC) and calibration (i.e. the agreement between predicted and observed outcome) was assessed with the Hosmer–Lemeshow “goodness-of-fit” test. Results: Overall model performance of the 3D-CRT based predictive models for XER 6M and STIC 6M was significantly worse in terms of the Brier score and R 2 Nagelkerke among patients treated with IMRT. Moreover the AUC for both 3D-CRT based models in the IMRT treated patients were markedly lower. The Hosmer–Lemeshow test showed a significant disagreement for both models between predicted risk and observed outcome. Conclusion: 3D-CRT based models for patient-rated xerostomia and sticky saliva among head and neck cancer patients treated with primary radiotherapy or

Intensity-modulated three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Mohan, Radhe

1996-01-01

Optimized intensity-modulated treatments one of the important advances in photon radiotherapy. Intensity modulation provides a greatly increased control over dose distributions. Such control can be maximally exploited to achieve significantly higher levels of conformation to the desired clinical objectives using sophisticated optimization techniques. Safe, rapid and efficient delivery of intensity-modulated treatments has become feasible using a dynamic multi-leaf collimator under computer control. The need for all other field shaping devices such as blocks, wedges and compensators is eliminated. Planning and delivery of intensity-modulated treatments is amenable to automation and development of class solutions for each treatment site and stage which can be implemented not only at major academic centers but on a wide scale. A typical treatment involving as many as 10 fields can be delivered in times shorter than much simpler conventional treatments. The main objective of the course is to give an overview of the current state of the art of planning and delivery methods of intensity-modulated treatments. Specifically, the following topics will be covered using representative optimized plans and treatments: 1. A typical procedure for planning and delivering an intensity-modulated treatment. 2. Quantitative definition of criteria (i.e., the objective function) of optimization of intensity-modulated treatments. Clinical relevance of objectives and the dependence of the quality of optimized intensity-modulated plans upon whether the objectives are stated purely in terms of simple dose or dose-volume criteria or whether they incorporate biological indices. 3. Importance of the lateral transport of radiation in the design of intensity-modulated treatments. Impact on dose homogeneity and the optimum choice of margins. 4. Use of intensity-modulated treatments in escalation of tumor dose for the same or lower normal tissue dose. Fractionation of intensity-modulated treatments

Intensity-modulated three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Mohan, Radhe

1997-01-01

Optimized intensity-modulated treatments one of the important advances in photon radiotherapy. Intensity modulation provides a greatly increased control over dose distributions. Such control can be maximally exploited to achieve significantly higher levels of conformation to the desired clinical objectives using sophisticated optimization techniques. Safe, rapid and efficient delivery of intensity-modulated treatments has become feasible using a dynamic multi-leaf collimator under computer control. The need for all other field shaping devices such as blocks, wedges and compensators is eliminated. Planning and delivery of intensity-modulated treatments is amenable to automation and development of class solutions for each treatment site and stage which can be implemented not only at major academic centers but on a wide scale. A typical treatment involving as many as 10 fields can be delivered in times shorter than much simpler conventional treatments. The main objective of the course is to give an overview of the current state of the art of planning and delivery methods of intensity-modulated treatments. Specifically, the following topics will be covered using representative optimized plans and treatments: 1. A typical procedure for planning and delivering an intensity-modulated treatment. 2. Quantitative definition of criteria (i.e., the objective function) of optimization of intensity-modulated treatments. Clinical relevance of objectives and the dependence of the quality of optimized intensity-modulated plans upon whether the objectives are stated purely in terms of simple dose or dose-volume criteria or whether they incorporate biological indices. 3. Importance of the lateral transport of radiation in the design of intensity-modulated treatments. Impact on dose homogeneity and the optimum choice of margins. 4. Use of intensity-modulated treatments in escalation of tumor dose for the same or lower normal tissue dose. Fractionation of intensity-modulated treatments

Debate about breast cancer: 'Cons: Intraoperative radiotherapy'; Debats autour du cancer du sein: 'contre' la radiotherapie peroperatoire

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Bourgier, C.; Heymann, S.; Verstraet, R.; Biron, B.; Marsiglia, H. [Departement de radiotherapie, institut Gustave-Roussy, 114, rue edouard-Vaillant, 94800 Villejuif (France)

2011-10-15

Early breast cancer incidence increases owing to mammography screening. Hypo-fractionated radiotherapy is more and more proposed in women with low local relapse risk breast cancer, especially accelerated partial breast irradiation. Various irradiation modalities have been reported: brachytherapy, intraoperative irradiation, 3D-conformal accelerated partial breast irradiation. We describe limitations of intraoperative irradiation and the advantages of alternative techniques. (authors)

Dosimetry in radiotherapy. V.1

International Nuclear Information System (INIS)

1988-01-01

A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

Effect of Concurrent High-Dose Cisplatin Chemotherapy and Conformal Radiotherapy on Cervical Esophageal Cancer Survival

International Nuclear Information System (INIS)

Huang Shaohui; Lockwood, Gina; Brierley, James; Cummings, Bernard; Kim, John; Wong, Rebecca; Bayley, Andrew; Ringash, Jolie

2008-01-01

Purpose: To determine whether a change in treatment policy to conformal, elective nodal radiotherapy and concurrent high-dose cisplatin improved survival for cervical esophageal cancer patients. Methods and Materials: All cervical esophageal cancer patients treated between 1997 and 2005 were restaged (1983 American Joint Committee on Cancer criteria). Patients treated before 2001 (previous cohort [PC]) were compared with those treated from 2001 onward (recent cohort [RC]). The PC institutional chemoradiotherapy protocol was 54 Gy in 20 fractions within 4 weeks, with 5-fluorouracil (1,000 mg/m 2 ) on Days 1-4 and either mitomycin C (10 mg/m 2 ) or cisplatin (75 mg/m 2 ) on Day 1. The RC institutional chemoradiotherapy protocol was conformal radiotherapy, 70 Gy in 35 fractions within 7 weeks, to the primary tumor and elective nodes, with high-dose cisplatin (100 mg/m 2 ) on Days 1, 22, and 43. Results: The median follow-up was 3.1 years (PC, 8.1 and RC, 2.3). Of 71 patients (25 women and 46 men), 21 of 29 in the PC and 29 of 42 in the RC were treated curatively (curative subgroup, n = 50). Between the two groups, no differences in overall survival or locoregional relapse-free survival were seen. The overall survival rate at 2 and 5 years was 35% (range, 24-47%) and 21% (range, 12-32%) in the whole group and 46% (range 32-60%) and 28% (range, 15-42%) in the curative group, respectively. In the curative group, no statistically significant prognostic factors were found. Trends toward better locoregional relapse-free survival were seen in women (2-year rate, 73% vs. for men, 36%; p = 0.08) and in patients aged >64 years (2-year rate, 68% vs. age ≤64 years, 34%; p = 0.10). Conclusion: No survival improvement could be demonstrated after changing the treatment policy to high-dose cisplatin-based, conventionally fractionated conformal chemoradiotherapy. Female gender and older age might predict for better outcomes

Status of Radiotherapy around the World: Radiotherapy in China. Chapter 25.6

International Nuclear Information System (INIS)

Zhu, Ci; Yin, Wei Bo; Chen, Bo; Zhang, Chun Li; Zhang, Hong Zhi; Li, Ye Xiong

2017-01-01

China’s experience of using radiotherapy to treat cancer began with the installation of the first superficial X ray machine at Peking Union Medical College Hospital in early 1920, followed by the first 200 kV deep X ray machine installed at the French Hospital in Shanghai in 1923, and the first Chinese radiotherapy department established at the Affiliated Hospital of Peking University in 1932. However, the field of radiotherapy in China was still in its infancy between the 1930s and 1960s, as all operating machines were imported from foreign countries, making radiotherapy very difficult to access for cancer patients. Progress was slow until the mid-1970s, when the first batch of megavoltage machines (cobalt-60 machines and linacs) was produced by Chinese manufacturers. Owing to the efforts of radiotherapy pioneers such as Wu Huanxing, Gu Xianzhi, Liu Taifu, and Yin Weibo, who brought radiotherapy to China and shaped how Chinese patients would be treated today, radiotherapy was installed as one of the mainstream modalities of cancer treatment. In 1986, the China Society for Radiation Oncology (CSTRO) was founded, indicating that a network advancing radiation oncology practice in China was taking shape. One year later, the first issue of the Chinese Journal of Radiation Oncology was published, offering a platform for the timely exchange and sharing of laboratory and clinical research outcomes among radiation oncology professions across the country. During the past two decades, with the introduction of the gamma knife and stereotactic radiotherapy, 3-D conformal radiotherapy, IMRT, IGRT and other advanced techniques, China experienced not only a big jump in its radiotherapy equipment and facilities, but also a dramatic growth in the excellence of radiation oncology specialist staff nationwide

Radiological response and dosimetry in physical phantom of head and neck for 3D conformational radiotherapy

International Nuclear Information System (INIS)

Thompson, Larissa

2013-01-01

Phantoms are tools for simulation of organs and tissues of the human body in radiology and radiotherapy. This thesis describes the development, validation and, most importantly, the use of a physical head and neck phantom in radiology and radiotherapy, with the purpose of evaluating dose distribution using Gafchromic EBT2 film in 15 MV 3D conformal radiotherapy. The work was divided in two stages, (1) development of new equivalent tissues and improvement of the physical phantom, and (2) use of the physical phantom in experimental dosimetry studies. In phase (1) parameters such as mass density, chemical composition of tissues, anatomical and biometric measurements were considered, as well as aspects of imaging by computed tomography (CT) and radiological response representation in Hounsfield Units (HU), which were compared with human data. Radiological experiments of in-phantom simulated brain pathologies were also conducted. All those results matched human-sourced data, therefore the physical phantom is a suitable simulator that may be used to enhance radiological protocols and education in medical imaging. The main objective in phase (2) was to evaluate the spatial dose distribution in a brain tumor simulator inserted inside the head and neck phantom developed by the Ionizing Radiation Research Group (NRI), exposed to 15 MV 3D conformal radiotherapy, for internal dose assessment. Radiation planning was based on CT images of the physical phantom with a brain tumor simulator made with equivalent material. The treatment planning system (TPS), CAT3D software, used CT images and prescribed a dose of 200 cGy, distributed in three fields of radiation, in a T-shaped pattern. The TPS covered the planning treatment volume (PTV) with 97% of the prescribed dose. A solid water phantom and radiochromic Gafchromic EBT2 film were used for calibration procedures, generating a dose response curve as a function of optical density (OD). After calibration and irradiation, the film

Uniform stable conformal convolutional perfectly matched layer for enlarged cell technique conformal finite-difference time-domain method

International Nuclear Information System (INIS)

Wang Yue; Wang Jian-Guo; Chen Zai-Gao

2015-01-01

Based on conformal construction of physical model in a three-dimensional Cartesian grid, an integral-based conformal convolutional perfectly matched layer (CPML) is given for solving the truncation problem of the open port when the enlarged cell technique conformal finite-difference time-domain (ECT-CFDTD) method is used to simulate the wave propagation inside a perfect electric conductor (PEC) waveguide. The algorithm has the same numerical stability as the ECT-CFDTD method. For the long-time propagation problems of an evanescent wave in a waveguide, several numerical simulations are performed to analyze the reflection error by sweeping the constitutive parameters of the integral-based conformal CPML. Our numerical results show that the integral-based conformal CPML can be used to efficiently truncate the open port of the waveguide. (paper)

Beam monitoring in radiotherapy and hadron-therapy

International Nuclear Information System (INIS)

Fontbonne, J.M.

2012-01-01

Radiotherapy techniques have evolved over the past twenty years. For photon beams, the development of tools such as multi leaf collimators, machines such as Cyberknife or tomo-therapy, have improved the conformation of treatments to the tumor volume and lowered maximum dose to healthy tissue. In another register, the use of proton-therapy is expanding in all countries and the development of carbon ions beams for hadron-therapy is also increasing. If techniques improve, the control requirements for the monitoring of the dose administered to patients are always the same. This document presents, first, the ins and outs of the different techniques of external beam radiotherapy: photon treatments, protons and hadrons. Starting from the basis of clinical requirements, it sets the variables to be measured in order to ensure the quality of treatment for the different considered modalities. It then describes some implementations, based on precise and rigorous specifications, for the monitoring and measurement of beams delivered by external beam radiotherapy equipments. Two instrumental techniques are particularly highlighted, plastic scintillators dosimetry for the control of megavoltage photon beams and ionization chamber dosimetry applied to proton-therapy or radiobiology experiments conducted at the GANIL facility. Analyzes and perspectives, based on the recent developments of treatment techniques, are delivered in conclusion and can serve as guide for future instrumental developments. (author)

Association of anorectal dose-volume histograms and impaired fecal continence after 3D conformal radiotherapy for carcinoma of the prostate

International Nuclear Information System (INIS)

Vordermark, Dirk; Schwab, Michael; Ness-Dourdoumas, Rhea; Sailer, Marco; Flentje, Michael; Koelbl, Oliver

2003-01-01

Purpose: The late toxicity of fecal incontinence after pelvic radiotherapy is now frequently recognized but the etiology poorly understood. We therefore investigated associations between dose-volume histogram (DVH) parameters of the rectum and the anal canal with fecal continence as measured by an established 10-item questionnaire. Methods and materials: Forty-four patients treated for carcinoma of the prostate with 58-72 Gy of 3D conformal radiotherapy between 1995 and 1999 who completed the questionnaire formed the study population. Total continence scores of treated patients obtained 1.5 years (median) after radiotherapy were compared to a control group of 30 patients before radiotherapy. Median, mean, minimum and maximum doses as well as the volume (% and ml) treated to 40, 50, 60 and 70 Gy were determined separately for anal canal and rectum. DVH parameters were correlated with total continence score (Spearman rank test) and patients grouped according to observed continence were compared regarding DVH values (Mann-Whitney U-test). Results: Median fecal continence scores were significantly worse in the irradiated than in the control group (31 vs. 35 of a maximum 36 points). In treated patients, 59%/27%/14% were classified as fully continent, slightly incontinent and severely incontinent. Continence was similar in the 58-to-62-Gy, 66-Gy and 68-to-72-Gy dose groups. No DVH parameter was significantly correlated with total continence score, but severely incontinent patients had a significantly higher minimum dose to the anal canal than fully continent/slightly incontinent, accompanied by portals extending significantly further inferiorly with respect to the ischial tuberosities. Conclusions: Excluding the inferior part of the anal canal from the treated volume in 3D conformal therapy for carcinoma of the prostate appears to be a promising strategy to prevent radiation-induced fecal incontinence

Propensity Score-based Comparison of Long-term Outcomes With 3-Dimensional Conformal Radiotherapy vs Intensity-Modulated Radiotherapy for Esophageal Cancer

International Nuclear Information System (INIS)

Lin, Steven H.; Wang Lu; Myles, Bevan; Thall, Peter F.; Hofstetter, Wayne L.; Swisher, Stephen G.; Ajani, Jaffer A.; Cox, James D.; Komaki, Ritsuko; Liao Zhongxing

2012-01-01

Purpose: Although 3-dimensional conformal radiotherapy (3D-CRT) is the worldwide standard for the treatment of esophageal cancer, intensity modulated radiotherapy (IMRT) improves dose conformality and reduces the radiation exposure to normal tissues. We hypothesized that the dosimetric advantages of IMRT should translate to substantive benefits in clinical outcomes compared with 3D-CRT. Methods and Materials: An analysis was performed of 676 nonrandomized patients (3D-CRT, n=413; IMRT, n=263) with stage Ib-IVa (American Joint Committee on Cancer 2002) esophageal cancers treated with chemoradiotherapy at a single institution from 1998-2008. An inverse probability of treatment weighting and inclusion of propensity score (treatment probability) as a covariate were used to compare overall survival time, interval to local failure, and interval to distant metastasis, while accounting for the effects of other clinically relevant covariates. The propensity scores were estimated using logistic regression analysis. Results: A fitted multivariate inverse probability weighted-adjusted Cox model showed that the overall survival time was significantly associated with several well-known prognostic factors, along with the treatment modality (IMRT vs 3D-CRT, hazard ratio 0.72, P<.001). Compared with IMRT, 3D-CRT patients had a significantly greater risk of dying (72.6% vs 52.9%, inverse probability of treatment weighting, log-rank test, P<.0001) and of locoregional recurrence (P=.0038). No difference was seen in cancer-specific mortality (Gray's test, P=.86) or distant metastasis (P=.99) between the 2 groups. An increased cumulative incidence of cardiac death was seen in the 3D-CRT group (P=.049), but most deaths were undocumented (5-year estimate, 11.7% in 3D-CRT vs 5.4% in IMRT group, Gray's test, P=.0029). Conclusions: Overall survival, locoregional control, and noncancer-related death were significantly better after IMRT than after 3D-CRT. Although these results need

Visual Outcome and Tumor Control After Conformal Radiotherapy for Patients With Optic Nerve Sheath Meningioma

International Nuclear Information System (INIS)

Arvold, Nils D.; Lessell, Simmons; Bussiere, Marc; Beaudette, Kevin; Rizzo, Joseph F.; Loeffler, Jay S.; Shih, Helen A.

2009-01-01

Purpose: Optic nerve sheath meningioma (ONSM) is a rare tumor that almost uniformly leads to visual dysfunction and even blindness without intervention. Because surgical extirpation carries a high risk of postoperative blindness, vision-sparing treatment strategies are desirable. Methods and Materials: We retrospectively reviewed the outcomes of 25 patients (25 optic nerves) with ONSM, treated at a single institution with conformal fractionated radiotherapy by either stereotactic photon or proton radiation. Primary endpoints were local control and visual acuity. Results: The patients presented with symptoms of visual loss (21) or orbital pain (3) or were incidentally diagnosed by imaging (3). The mean age was 44 years, and 64% were female patients. The indication for treatment was the development or progression of symptoms. Of the patients, 13 were treated with photons, 9 were treated with protons, and 3 received a combination of photons and protons. The median dose delivered was 50.4 gray equivalents (range, 45-59.4 gray equivalents). Median follow-up after radiotherapy was 30 months (range, 3-168 months), with 3 patients lost to follow-up. At most recent follow-up, 21 of 22 patients (95%) had improved (14) or stable (7) visual acuity. One patient had worsened visual acuity after initial postirradiation improvement. Of the 22 patients, 20 (95%) had no radiographic progression. Three patients had evidence of asymptomatic, limited retinopathy on ophthalmologic examination, and one had recurrent ONSM 11 years after treatment. Conclusions: Highly conformal, fractionated radiation therapy for symptomatic primary ONSM provides tumor control and improvement in visual function in most cases, with minimal treatment-induced morbidity. Longer follow-up is needed to assess the durability of tumor control and treatment-related late effects.

Novel radiotherapy techniques for involved-field and involved-node treatment of mediastinal Hodgkin lymphoma. When should they be considered and which questions remain open

Energy Technology Data Exchange (ETDEWEB)

Lohr, Frank; Koeck, Julia; Abo-Madyan, Yasser [University of Heidelberg, Department of Radiation Oncology, University Medical Center Mannheim, Mannheim (Germany); Georg, Dietmar; Knaeusl, Barbara; Dieckmann, Karin [Medical University Vienna/AKH Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, Vienna (Austria); Medical University Vienna/AKH Vienna, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Comprehensive Cancer Center, Vienna (Austria); Cozzi, Luca [Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Eich, Hans Theodor [University Hospital, Department of Radiotherapy, Muenster (Germany); Weber, Damien C. [Paul Scherrer Institute, University of Bern, Center for Proton Therapy, Bern (Switzerland); Fiandra, Christian; Ricardi, Umberto [University of Torino, Radiation Oncology Unit, Department of Oncology, Turin (Italy); Mueller, Rolf-Peter [University of Cologne, Department of Radiation Oncology, Cologne (Germany); Engert, Andreas [University of Cologne, Department of Medical Oncology, Cologne (Germany)

2014-10-15

Hodgkin lymphoma (HL) is a highly curable disease. Reducing late complications and second malignancies has become increasingly important. Radiotherapy target paradigms are currently changing and radiotherapy techniques are evolving rapidly. This overview reports to what extent target volume reduction in involved-node (IN) and advanced radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT) and proton therapy-compared with involved-field (IF) and 3D radiotherapy (3D-RT)- can reduce high doses to organs at risk (OAR) and examines the issues that still remain open. Although no comparison of all available techniques on identical patient datasets exists, clear patterns emerge. Advanced dose-calculation algorithms (e.g., convolution-superposition/Monte Carlo) should be used in mediastinal HL. INRT consistently reduces treated volumes when compared with IFRT with the exact amount depending on the INRT definition. The number of patients that might significantly benefit from highly conformal techniques such as IMRT over 3D-RT regarding high-dose exposure to organs at risk (OAR) is smaller with INRT. The impact of larger volumes treated with low doses in advanced techniques is unclear. The type of IMRT used (static/rotational) is of minor importance. All advanced photon techniques result in similar potential benefits and disadvantages, therefore only the degree-of-modulation should be chosen based on individual treatment goals. Treatment in deep inspiration breath hold is being evaluated. Protons theoretically provide both excellent high-dose conformality and reduced integral dose. Further reduction of treated volumes most effectively reduces OAR dose, most likely without disadvantages if the excellent control rates achieved currently are maintained. For both IFRT and INRT, the benefits of advanced radiotherapy techniques depend on the individual patient/target geometry. Their use should therefore be decided case by case with comparative treatment planning

Late xerostomia after intensity-modulated conformational radiotherapy of upper aero-digestive tract cancers: study 2004-03 by the head and neck oncology and radiotherapy Group (Gortec)

International Nuclear Information System (INIS)

Toledano, I.; Lapeyre, M.; Graff, P.; Serre, C.; Bensadoun, R.J.; Bensadoun, R.J.; Ortholan, C.; Calais, G.; Alfonsi, M.; Giraud, P.; Racadot, S.

2010-01-01

The authors report a retrospective assessment of late xerostomia according to the RTOG (Radiation Therapy Oncology Group) classification of the European Organization for Research and Treatment of Cancer (EORTC) among patients treated by intensity-modulated conformational radiotherapy (IMRT) and suffering from upper aero-digestive tract carcinomas of different stages. Some of these patients have bee operated, and some have been treated by chemotherapy. It appears that the IMRT results in a reduction of late xerostomia, and even in an absence of salivary toxicity. Short communication

Film dosimetry in conformal radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Danciu, C; Proimos, B S [Patras Univ. (Greece). Dept. of Medical Physics

1995-12-01

Dosimetry, through a film sandwiched in a transverse cross-section of a solid phantom, is a method of choice in Conformal Radiotherapy because: (a) the blackness (density) of the film at each point offers a measure of the total dose received at that point, and (b) the film is easily calibrated by exposing a film strip in the same cross-section, through a stationary field. The film must therefore have the following properties: (a) it must be slow, in order not to be overexposed, even at a therapeutic dose of 200 cGy, and (b) the response of the film (density versus dose curve) must be independent of the photon energy spectrum. A few slow films were compared. It was found that the Kodak X-Omat V for therapy verification was the best choice. To investigate whether the film response was independent of the photon energy, response curves for six depths, starting from the depth of maximum dose to the depth of 25 cm, in solid phantom were derived. The vertical beam was perpendicular to the anterior surface of the phantom, which was at the distance of 100 cm from the source and the field was 15x15 cm at that distance. This procedure was repeated for photon beams emitted by a Cobalt-60 unit, two 6 MV and 15 MV Linear Accelerators, as well as a 45 MV Betatron. For each of those four different beams the film response was the same for all six depths. The results, as shown in the diagrams, are very satisfactory. The response curve under a geometry similar to that actually applied, when the film is irradiated in a transverse cross-section of the phantom, was derived. The horizontal beam was almost parallel (angle of 85) to the plane of the film. The same was repeated with the central ray parallel to the film (angle 90) and at a distance of 1.5 cm from the horizontal film. The field size was again 15x15 at the lateral entrance surface of the beam. The response curves remained the same, as when the beam was perpendicular to the films.

Conformal radiotherapy of locally advanced bile duct carcinoma; Radiotherapie conformationnelle des cholangiocarcinomes de la voie biliaire principale localement evolues

Energy Technology Data Exchange (ETDEWEB)

Bouras, N.; Caudry, M.; Bonnel, C.; Trouette, R.; Demeaux, H.; Maire, J.P. [Centre Hospitalier Universitaire, Hopital Saint-Andre, Service de Radiotherapie, 33 - Bordeaux (France); Saric, J.; Rullier, E. [Centre Hospitalier Universitaire, Hopital Saint-Andre, Service de Chirurgie Viscerale et de Transplantation Hepatique, 33 - Bordeaux (France)

2002-02-01

Purpose. - Retrospective study of 23 patients treated with conformal radiotherapy for a locally advanced bile duct carcinoma. Patients and methods. - Eight cases were irradiated after a radical resection (RO), because they were N+; seven after microscopically incomplete resection (R1) ; seven were not resected (R2). A dose of 45 of 50 Gy was delivered, followed by a boost up to 60 Gy in R1 and R2 groups. Concomitant chemotherapy was given in 15 cases. Results.-Late toxicity included a stenosis of the duodenum, and one of the biliary anastomosis. Two patients died from cholangitis, the mechanism of which remains unclear. Five patients are in complete remission, six had a local relapse, four developed a peritoneal carcinosis, and six distant metastases. Actuarial survival rate is 75%, 28% and 7% at 1, 3 and 5 years, respectively (median: 16.5 months). Seven patients are still alive with a 4 to 70 months follow-up. Survival is similar in the 3 small subgroups. The poor local control among RON+ cases might be related to the absence of a boost to the 'tumor bed'. In R1 patients, relapses were mainly distant metastases, where'as local and peritoneal recurrences predominated in R2. Conclusion. - Conformal radio-chemotherapy delivering 60 Gy represents a valuable palliative approach in locally advanced biliary carcinoma. (authors)

Side effects after radiotherapy of age-related macular degeneration with the Nijmegen technique.

NARCIS (Netherlands)

Hoyng, C.B.; Tromp, A.I.; Meulendijks, C.F.M.; Leys, A.; Maazen, R.W.M. van der; Deutman, A.F.; Vingerling, J.R.

2002-01-01

BACKGROUND: In a randomized trial concerning radiotherapy for age-related macular degeneration, fluorescein angiograms were taken of controls and patients. In this study the frequency of side effects in eyes receiving radiotherapy with the Nijmegen technique is compared with the findings in the eyes

The progress in radiotherapy techniques and it's clinical implications

International Nuclear Information System (INIS)

Reinfuss, M.; Walasek, T.; Byrski, E.; Blecharz, P.

2011-01-01

Three modem radiotherapy techniques were introduced into clinical practice at the onset of the 21 st century - stereotactic radiation therapy (SRT), proton therapy and carbon-ion radiotherapy. Our paper summarizes the basic principles of physics, as well as the technical reqirements and clinical indications for those techniques. SRT is applied for intracranial diseases (arteriovenous malformations, acoustic nerve neuromas, brain metastases, skull base tumors) and in such cases it is referred to as stereotactic radiosurgery (SRS). Techniques used during SRS include GammaKnife, CyberKnife and dedicated linacs. SRT can also be applied for extracranial disease (non-small cell lung cancer, lung metastases, spinal and perispinal tumors, primary liver tumors, breast cancer, pancreatic tumors, prostate cancer, head and neck tumors) and in such cases it is referred to as stereotactic body radiation therapy (SBRT). Eye melanomas, skull base and cervical spine chordomas and chordosarcomas, as well as childhood neoplasms, are considered to be the classic indications for proton therapy. Clinical trials are currently conducted to investigate the usefulness of proton beam in therapy of non-small cell lung cancer, prostate cancer, head and neck tumors, primary liver and oesophageal cancer Carbon-ion radiotherapy is presumed to be more advantageous than proton therapy because of its higher relative biological effectiveness (RBE) and possibility of real-time control of the irradiated volume under PET visualization. The basic indications for carbon-ion therapy are salivary glands neoplasms, selected types of soft tissue and bone sarcomas, skull base chordomas and chordosarcomas, paranasal sinus neoplasms, primary liver cancers and inoperable rectal adenocarcinoma recurrences. (authors)

Simultaneous integrated boost intensity-modulated radiotherapy versus 3-dimensional conformal radiotherapy in preoperative concurrent chemoradiotherapy for locally advanced rectal cancer

Energy Technology Data Exchange (ETDEWEB)

Bae, Bong Kyung; Kang, Min Kyul; Kim, Jae Chul [Dept. of Radiation Oncology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Kim, Min Young; Choi, Gyu Seog; Kim, Jong Gwang; Kang, Byung Woog; Kim, Hye Jin; Park, Soo Yeun [Kyungpook National University Chilgok Hospital, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

2017-09-15

To evaluate the feasibility of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for preoperative concurrent chemoradiotherapy (PCRT) in locally advanced rectal cancer (LARC), by comparing with 3-dimensional conformal radiotherapy (3D-CRT). Patients who were treated with PCRT for LARC from 2015 January to 2016 December were retrospectively enrolled. Total doses of 45 Gy to 50.4 Gy with 3D-CRT or SIB-IMRT were administered concomitantly with 5-fluorouracil plus leucovorin or capecitabine. Surgery was performed 8 weeks after PCRT. Between PCRT and surgery, one cycle of additional chemotherapy was administered. Pathologic tumor responses were compared between SIB-IMRT and 3D-CRT groups. Acute gastrointestinal, genitourinary, hematologic, and skin toxicities were compared between the two groups based on the RTOG toxicity criteria. SIB-IMRT was used in 53 patients, and 3D-CRT in 41 patients. After PCRT, no significant differences were noted in tumor responses, pathologic complete response (9% vs. 7%; p = 1.000), pathologic tumor regression Grade 3 or higher (85% vs. 71%; p = 0.096), and R0 resection (87% vs. 85%; p = 0.843). Grade 2 genitourinary toxicities were significantly lesser in the SIB-IMRT group (8% vs. 24%; p = 0.023), but gastrointestinal toxicities were not different across the two groups. SIB-IMRT showed lower GU toxicity and similar tumor responses when compared with 3D-CRT in PCRT for LARC.

Establishing stereotactic body radiotherapy with flattening filter free techniques in the treatment of pulmonary lesions - initial experiences from a single institution

International Nuclear Information System (INIS)

Rieber, Juliane; Tonndorf-Martini, Eric; Schramm, Oliver; Rhein, Bernhard; König, Laila; Adeberg, Sebastian; Meyerhof, Eva; Mohr, Angela; Kappes, Jutta; Hoffmann, Hans; Debus, Jürgen; Rieken, Stefan

2016-01-01

Stereotactic body radiotherapy (SBRT) using flattening filter free (FFF)-techniques has been increasingly applied during the last years. However, clinical studies investigating this emerging technique are still rare. Hence, we analyzed toxicity and clinical outcome of pulmonary SBRT with FFF-techniques and performed dosimetric comparison to conventional techniques using flattening filters (FF). Between 05/2014 and 06/2015, 56 consecutive patients with 61 pulmonary lesions were treated with SBRT in FFF-mode. Central lesions received 8 × 7.5 Gy delivered to the conformally enclosing 80 %-isodose, while peripheral lesions were treated with 3 × 15 Gy, prescribed to the 65 %-isodose. Early and late toxicity (after 6 months) as well as initial clinical outcomes were evaluated. Furthermore, [deleted] plan quality and efficiency were evaluated by analyzing conformity, beam- on and total treatment delivery times in comparison to plans with FF-dose application. Median follow-up time was 9.3 months (range 1.5–18.0 months). Early toxicity was low with only 5 patients (8.9 %) reporting CTCAE 2° or higher side-effects. Only one patient (1.8 %) was diagnosed with radiation-induced pneumonitis CTCAE 3°, while 2 (3.6 %) patients suffered from pneumonitis CTCAE 2°. After 6 months, no toxicity greater than CTCAE 2° was reported. 1-year local progression-free survival, distant progression-free survival and overall survival were 92.8 %, 78.0 %, and 94.4 %, respectively. While plan quality was similar for FFF- and FF-plans in respect to conformity (p = 0.275), median beam-on time as well as total treatment time were significantly reduced for SBRT in FFF-mode compared to FF-mode (p ≤ 0.001, p ≤ 0.001). Patient treatment with SBRT using FFF-techniques is safe and provides promising clinical results with only modest toxicity at significantly increased dose delivery speed

Technological advances in radiotherapy of rectal cancer: opportunities and challenges.

Science.gov (United States)

Appelt, Ane L; Sebag-Montefiore, David

2016-07-01

This review summarizes the available evidence for the use of modern radiotherapy techniques for chemoradiotherapy for rectal cancer, with specific focus on intensity-modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) techniques. The dosimetric benefits of IMRT and VMAT are well established, but prospective clinical studies are limited, with phase I-II studies only. Recent years have seen the publication of a few larger prospective patient series as well as some retrospective cohorts, several of which include much needed late toxicity data. Overall results are encouraging, as toxicity levels - although varying across reports - appear lower than for 3D conformal radiotherapy. Innovative treatment techniques and strategies which may be facilitated by the use of IMRT/VMAT include simultaneously integrated tumour boost, adaptive treatment, selective sparing of specific organs to enable chemotherapy escalation, and nonsurgical management. Few prospective studies of IMRT and VMAT exist, which causes uncertainty not just in regards to the clinical benefit of these technologies but also in the optimal use. The priority for future research should be subgroups of patients who might receive relatively greater benefit from innovative treatment techniques, such as patients receiving chemoradiotherapy with definitive intent and patients treated with dose escalation.

Relation between the treated region of the patient with ca. of the uterine cervix and her body-type in whole pelvis irradiation with conformation technique

International Nuclear Information System (INIS)

Morita, Kozo; Kakehi, Masae

1975-01-01

In whole pelvis irradiation using the conformation technique for the patient with carcinoma of the uterine cervix, standardization of the shape of the treated region was tried on the basis of measuring the pelvis in X-ray films. This was done on the X-rays of 200 patients with carcinoma of the uterine cervix. The body-type of the patient the most remarkably influenced the shape of the treated region. Ten clinical types of cam-group (treated region) were determined, in order to perform conformation radiotherapy for carcinoma of the uterine cervix. Although the shape of the treated region could also be changed by the invasion of the lesion, the position of the portio and the general condition of the patients, these 10 standard types of cam-group can be applied practically to almost all of the patients. (Evans, J.)

Radiation dose verification using real tissue phantom in modern radiotherapy techniques

International Nuclear Information System (INIS)

Gurjar, Om Prakash; Mishra, S.P.; Bhandari, Virendra; Pathak, Pankaj; Patel, Prapti; Shrivastav, Garima

2014-01-01

In vitro dosimetric verification prior to patient treatment has a key role in accurate and precision radiotherapy treatment delivery. Most of commercially available dosimetric phantoms have almost homogeneous density throughout their volume, while real interior of patient body has variable and varying densities inside. In this study an attempt has been made to verify the physical dosimetry in actual human body scenario by using goat head as 'head phantom' and goat meat as 'tissue phantom'. The mean percentage variation between planned and measured doses was found to be 2.48 (standard deviation (SD): 0.74), 2.36 (SD: 0.77), 3.62 (SD: 1.05), and 3.31 (SD: 0.78) for three-dimensional conformal radiotherapy (3DCRT) (head phantom), intensity modulated radiotherapy (IMRT; head phantom), 3DCRT (tissue phantom), and IMRT (tissue phantom), respectively. Although percentage variations in case of head phantom were within tolerance limit (< ± 3%), but still it is higher than the results obtained by using commercially available phantoms. And the percentage variations in most of cases of tissue phantom were out of tolerance limit. On the basis of these preliminary results it is logical and rational to develop radiation dosimetry methods based on real human body and also to develop an artificial phantom which should truly represent the interior of human body. (author)

Radiation dose verification using real tissue phantom in modern radiotherapy techniques

Directory of Open Access Journals (Sweden)

Om Prakash Gurjar

2014-01-01

Full Text Available In vitro dosimetric verification prior to patient treatment has a key role in accurate and precision radiotherapy treatment delivery. Most of commercially available dosimetric phantoms have almost homogeneous density throughout their volume, while real interior of patient body has variable and varying densities inside. In this study an attempt has been made to verify the physical dosimetry in actual human body scenario by using goat head as "head phantom" and goat meat as "tissue phantom". The mean percentage variation between planned and measured doses was found to be 2.48 (standard deviation (SD: 0.74, 2.36 (SD: 0.77, 3.62 (SD: 1.05, and 3.31 (SD: 0.78 for three-dimensional conformal radiotherapy (3DCRT (head phantom, intensity modulated radiotherapy (IMRT; head phantom, 3DCRT (tissue phantom, and IMRT (tissue phantom, respectively. Although percentage variations in case of head phantom were within tolerance limit (< ± 3%, but still it is higher than the results obtained by using commercially available phantoms. And the percentage variations in most of cases of tissue phantom were out of tolerance limit. On the basis of these preliminary results it is logical and rational to develop radiation dosimetry methods based on real human body and also to develop an artificial phantom which should truly represent the interior of human body.

Breath-hold technique in conventional APPA or intensity-modulated radiotherapy for Hodgkin's lymphoma. Comparison of ILROG IS-RT and the GHSG IF-RT

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Kriz, Jan; Spickermann, Max; Lehrich, Philipp; Reinartz, Gabriele; Eich, Hans; Haverkamp, Uwe [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Schmidberger, Heinz [University Mainz, Department of Radiation Oncology, Mainz (Germany)

2015-09-15

The present study addresses the role of intensity-modulated radiotherapy (IMRT) in contrast to standard RT (APPA) for patients with Hodgkin's lymphoma (HL) with a focus on deep inspiration breath-hold (DIBH) technique and a comparison between the International Lymphoma Radiation Oncology Group (ILROG) Involved Site Radiotherapy (IS-RT) versus the German Hodgkin Study Group (GHSG) Involved Field Radiotherapy (IF-RT). APPA treatment and 2 IMRT plans were compared for 11 patients with HL. Furthermore, treatment with DIBH versus free breathing (FB) and two different treatment volumes, i.e. IF-RT versus IS-RT, were compared. IMRT was planned as a sliding-window technique with 5 and 7 beam angles. For each patient 12 different treatment plans were calculated (132 plans). Following organs at risk (OAR) were analysed: lung, heart, spinal cord, oesophagus, female breast and skin. Comparisons of the different values with regard to dose-volume histograms (DVH), conformity and homogeneity indices were made. IS-RT reduces treatment volumes. With respect to the planning target volume (PTV), IMRT achieves better conformity but the same homogeneity. Regarding the D{sub mean} for the lung, IMRT shows increased doses, while RT in DIBH reduces doses. The IMRT shows improved values for D{sub max} concerning the spinal cord, whereas the APPA shows an improved D{sub mean} of the lung and the female breast. IS-RT reduces treatment volumes. Intensity-modulated radiotherapy shows advantages in the conformity. Treatment in DIBH also reduces the dose applied to the lungs and the heart. (orig.) [German] Ziel dieser Auswertung ist es, die konventionelle APPA-Feldanordnung mit der Intensitaetsmodulierten Radiotherapie (IMRT) bei Patienten mit Hodgkin-Lymphom (HL) zu vergleichen. Ein besonderer Fokus liegt hierbei auf der Bestrahlung in tiefer Inspiration und Atemanhaltetechnik (DIBH). Des Weiteren wurde die ''Involved-site''-Radiotherapie (IS-RT) der International

Anal wall sparing effect of an endorectal balloon in 3D conformal and intensity-modulated prostate radiotherapy.

Science.gov (United States)

Smeenk, Robert Jan; van Lin, Emile N J Th; van Kollenburg, Peter; Kunze-Busch, Martina; Kaanders, Johannes H A M

2009-10-01

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. 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). 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. 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.

Clinical experience with a new stereotactic localisation method for fractionated radiotherapy of extracranial lesions

International Nuclear Information System (INIS)

Engenhart-Cabillic, R.; Pastyr, O.; Wenz, F.; Debus, J.; Schlegel, W.; Bahner, M.L.; Wannenmacher, M.

1996-01-01

coordinates was 0.8 mm at the lower cervical spine (C7), 1.2 mm at the lower thoracic spine (T11) and 1.0 mm in the lumbar spine (L4). Conclusion: Over recent years, new 3D conformal technology have changed to improve local control and decrease treatment related morbidity. For conformal radiotherapy more complex treatment techniques are applied. These techniques require safe and reproducible repositioning. Our preliminary clinical data confirm the excellent long term stability of the stereotactic total body system. The positioning accuracy for bony structures is comparable to intracranial stereotactic radiotherapy. We will examine in a subsequent study if this technique will allow us to deliver highly conformal radiotherapy to avoid unnecessary radiation dose to critical adjacent normal tissue

Cost-effectiveness of modern radiotherapy techniques in locally advanced pancreatic cancer.

Science.gov (United States)

Murphy, James D; Chang, Daniel T; Abelson, Jon; Daly, Megan E; Yeung, Heidi N; Nelson, Lorene M; Koong, Albert C

2012-02-15

Radiotherapy may improve the outcome of patients with pancreatic cancer but at an increased cost. In this study, the authors evaluated the cost-effectiveness of modern radiotherapy techniques in the treatment of locally advanced pancreatic cancer. A Markov decision-analytic model was constructed to compare the cost-effectiveness of 4 treatment regimens: gemcitabine alone, gemcitabine plus conventional radiotherapy, gemcitabine plus intensity-modulated radiotherapy (IMRT); and gemcitabine with stereotactic body radiotherapy (SBRT). Patients transitioned between the following 5 health states: stable disease, local progression, distant failure, local and distant failure, and death. Health utility tolls were assessed for radiotherapy and chemotherapy treatments and for radiation toxicity. SBRT increased life expectancy by 0.20 quality-adjusted life years (QALY) at an increased cost of $13,700 compared with gemcitabine alone (incremental cost-effectiveness ratio [ICER] = $69,500 per QALY). SBRT was more effective and less costly than conventional radiotherapy and IMRT. An analysis that excluded SBRT demonstrated that conventional radiotherapy had an ICER of $126,800 per QALY compared with gemcitabine alone, and IMRT had an ICER of $1,584,100 per QALY compared with conventional radiotherapy. A probabilistic sensitivity analysis demonstrated that the probability of cost-effectiveness at a willingness to pay of $50,000 per QALY was 78% for gemcitabine alone, 21% for SBRT, 1.4% for conventional radiotherapy, and 0.01% for IMRT. At a willingness to pay of $200,000 per QALY, the probability of cost-effectiveness was 73% for SBRT, 20% for conventional radiotherapy, 7% for gemcitabine alone, and 0.7% for IMRT. The current results indicated that IMRT in locally advanced pancreatic cancer exceeds what society considers cost-effective. In contrast, combining gemcitabine with SBRT increased clinical effectiveness beyond that of gemcitabine alone at a cost potentially acceptable by

Long-Term Results of Conformal Radiotherapy for Progressive Airway Amyloidosis

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Truong, Minh Tam, E-mail: mitruong@bu.edu [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Grillone, Gregory A. [Department of Otolaryngology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Bohrs, Harry K.; Lee, Richard [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Sakai, Osamu [Department of Radiology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Berk, John L. [Department of Medicine, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States)

2012-06-01

Purpose: To evaluate the efficacy of conformal external beam radiotherapy (RT) for local control of progressive airway amyloidosis. Methods and Materials: We conducted a retrospective review of patients with biopsy-proven progressive airway amyloidosis treated with conformal RT between 2000 and 2006 at Boston Medical Center. The patients were evaluated for performance status and pulmonary function, with computed tomography and endoscopy after RT compared with the pretreatment studies. Local control was defined as the lack of progression of airway wall thickening on computed tomography imaging and stable endobronchial deposits by endoscopy. Results: A total of 10 symptomatic airway amyloidosis patients (3 laryngeal and 7 tracheobronchial) received RT to a median total dose of 20 Gy in 10 fractions within 2 weeks. At a median follow-up of 6.7 years (range, 1.5-10.3), 8 of the 10 patients had local control. The remaining 2 patients underwent repeat RT 6 and 8.4 months after initial RT, 1 for persistent bronchial obstruction and 1 for progression of subglottic amyloid disease with subsequent disease control. The Eastern Cooperative Oncology Group performance status improved at a median of 18 months after RT compared with the baseline values, from a median score of 2 to a median of 1 (p = .035). Airflow (forced expiratory volume in 1 second) measurements increased compared with the baseline values at each follow-up evaluation, reaching a 10.7% increase (p = .087) at the last testing (median duration, 64.8 months). Acute toxicity was limited to Grade 1-2 esophagitis, occurring in 40% of patients. No late toxicity was observed. Conclusions: RT prevented progressive amyloid deposition in 8 of 10 patients, resulting in a marginally increased forced expiratory volume in 1 second, and improved functional capacity, without late morbidity.

Modality comparison for small animal radiotherapy: A simulation study

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Bazalova, Magdalena, E-mail: bazalova@stanford.edu; Nelson, Geoff; Noll, John M.; Graves, Edward E. [Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States)

2014-01-15

the SARRP plan due to the sensitivity of the lower energy microCT beam to target heterogeneities and image noise. Conclusions: The two treatment planning examples demonstrate that modern small animal radiotherapy techniques employing image guidance, variable collimation, and multiple beam angles deliver superior dose distributions to small animal tumors as compared to conventional treatments using a single-field irradiator. For deep-seated mouse tumors, however, higher-energy conformal radiotherapy could result in higher doses to critical organs compared to lower-energy conformal radiotherapy. Treatment planning optimization for small animal radiotherapy should therefore be developed to take full advantage of the novel conformal systems.

Present and future of the Image Guided Radiotherapy (I.G.R.T.) and its applications in lung cancer treatment

International Nuclear Information System (INIS)

Lefkopoulos, D.; Ferreira, I.; Isambert, A.; Le Pechoux, C.; Mornex, F.

2007-01-01

These last years, the new irradiation techniques as the conformal 3D radiotherapy and the IMRT are strongly correlated with the technological developments in radiotherapy. The rigorous definition of the target volume and the organs at risk required by these irradiation techniques, imposed the development of various image guided patient positioning and target tracking techniques. The availability of these imaging systems inside the treatment room has lead to the exploration of performing real-time adaptive radiation therapy. In this paper we present the different image guided radiotherapy (IGRT) techniques and the adaptive radiotherapy (ART) approaches. IGRT developments are focused in the following areas: 1) biological imaging for better definition of tumor volume; 2) 4D imaging for modeling the intra-fraction organ motion; 3) on-board imaging system or imaging devices registered to the treatment machines for inter-fraction patient localization; and 4) treatment planning and delivery schemes incorporating the information derived from the new imaging techniques. As this paper is included in the 'Cancer Radiotherapie' special volume dedicated to the lung cancers, in the description of the different IGRT techniques we try to present the lung tumors applications when this is possible. (author)

Conkiss: Conformal Kidneys Sparing 3D Noncoplanar Radiotherapy Treatment for Pancreatic Cancer As an Alternative to IMRT

International Nuclear Information System (INIS)

Sebestyen, Zsolt; Kovacs, Peter; Gulyban, Akos; Farkas, Robert; Bellyei, Szabolcs; Liposits, Gabor; Szigeti, Andras; Esik, Olga; Derczy, Katalin; Mangel, Laszlo

2011-01-01

When treating pancreatic cancer using standard (ST) 3D conformal radiotherapy (3D-CRT) beam arrangements, the kidneys often receive a higher dose than their probable tolerance limit. Our aim was to elaborate a new planning method that-similarly to IMRT-effectively spares the kidneys without compromising the target coverage. Conformal kidneys sparing (CONKISS) 5-field, noncoplanar plans were compared with ST plans for 23 consecutive patients retrospectively. Optimal beam arrangements were used consisting of a left- and right-wedged beam-pair and an anteroposterior beam inclined in the caudal direction. The wedge direction determination (WEDDE) algorithm was developed to adjust the adequate direction of wedges. The aimed organs at risk (OARs) mean dose limits were: kidney <12 Gy, liver <25 Gy, small bowels <30 Gy, and spinal cord maximum <45 Gy. Conformity and homogeneity indexes with z-test were used to evaluate and compare the different planning approaches. The mean dose to the kidneys decreased significantly (p < 0.05): left kidney 7.7 vs. 10.7 Gy, right kidney 9.1 vs. 11.7 Gy. Meanwhile the mean dose to the liver increased significantly (18.1 vs. 15.0 Gy). The changes in the conformity, homogeneity, and in the doses to other OARs were not significant. The CONKISS method balances the load among the OARs and significantly reduces the dose to the kidneys, without any significant change in the conformity and homogeneity. Using 3D-CRT the CONKISS method can be a smart alternative to IMRT to enhance the possibility of dose escalation.

Phase II study of radiotherapy with three-dimensional conformal boost concurrent with paclitaxel and cisplatin for Stage IIIB non-small-cell lung cancer

International Nuclear Information System (INIS)

Kim, Young Seok; Yoon, Sang Min; Choi, Eun Kyung; Yi, Byong Yong; Kim, Jong Hoon; Ahn, Seung Do; Lee, Sang-wook; Shin, Seong Soo; Lee, Jung Shin; Suh, Cheolwon; Kim, Sang-We; Kim, Dong Soon; Kim, Woo Sung; Park, Heon Joo; Park, Charn Il

2005-01-01

Purpose: To evaluate the efficacy and toxicity of concurrent chemoradiotherapy with paclitaxel/cisplatin for Stage IIIB locally advanced non-small-cell lung cancer (NSCLC). Methods and Materials: Radiotherapy was administered to a total dose of 70.2 Gy (daily fraction of 1.8 Gy, 5 days/wk), over an 8-week period, combined with chemotherapy. The chemotherapy consisted of weekly 40 mg/m 2 of paclitaxel plus 20 mg/m 2 of cisplatin for 8 consecutive weeks. All patients received three-dimensional conformal radiotherapy (3D-CRT), based on computed tomography simulated planning after 41.4 Gy. The median follow-up period of survivors was 24 months. Results: Between January 2000 and October 2002, 135 patients with a median age of 60 years were enrolled and analyzed in this prospective trial. The overall response rate was 75% including 2 cases of complete response. The major patterns of failure were local failure and distant metastasis. The 2-year overall and progression-free survival rates were 37% and 18%, respectively. The median overall and progression-free survival times were 17 months and 9 months, respectively. Hematologic toxicity >Grade 2 was observed in 19% of patients and severe non-hematologic toxicity was infrequent. Conclusions: Three-dimensional conformal radiotherapy, combined with paclitaxel and cisplatin chemotherapy, was associated with a satisfactory outcome with manageable toxicity. Further investigations are needed to improve the local control

Breast-conserving radiation therapy using combined electron and intensity-modulated radiotherapy technique

International Nuclear Information System (INIS)

Li, J.G.; Williams, S.S.; Goffinet, D.R.; Boer, A.L.; Xing, L.

2000-01-01

An electron beam with appropriate energy was combined with four intensity modulated photon beams. The direction of the electron beam was chosen to be tilted 10-20 laterally from the anteroposterior direction. Two of the intensity-modulated photon beams had the same gantry angles as the conventional tangential fields, whereas the other two beams were rotated 15-25' toward the anteroposterior directions from the first two photon beams. An iterative algorithm was developed which optimizes the weight of the electron beam as well as the fluence profiles of the photon beams for a given patient. Two breast cancer patients with early-stage breast tumors were planned with the new technique and the results were compared with those from 3D planning using tangential fields as well as 9-field intensity-modulated radiotherapy (IMRT) techniques. The combined electron and IMRT plans showed better dose conformity to the target with significantly reduced dose to the ipsilateral lung and, in the case of the left-breast patient, reduced dose to the heart, than the tangential field plans. In both the right-sided and left-sided breast plans, the dose to other normal structures was similar to that from conventional plans and was much smaller than that from the 9-field IMRT plans. The optimized electron beam provided between 70 to 80% of the prescribed dose at the depth of maximum dose of the electron beam. The combined electron and IMRT technique showed improvement over the conventional treatment technique using tangential fields with reduced dose to the ipsilateral lung and the heart. The customized beam directions of the four IMRT fields also kept the dose to other critical structures to a minimum. (author)

Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

International Nuclear Information System (INIS)

Couto, Henrique Lima; Amorim, Washington Cancado; Guimaraes, Rodrigo

2014-01-01

Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

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Couto, Henrique Lima, E-mail: enriquecouto@hotmail.com [Santa Fe Women' s and Maternity Hospital, Belo Horizonte, MG (Brazil); Amorim, Washington Cancado; Guimaraes, Rodrigo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Hospital Geral; Ramires, Leandro Cruz; Castilho, Marcus Simoes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina; Dominguez, Lorena Lima Coto [Universidade Estacio de Sa (UNESA), Rio de Janeiro, EJ (Brazil)

2014-07-15

Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

Setup error in three-dimensional conformal radiotherapy for thoracic esophageal carcinoma

International Nuclear Information System (INIS)

Hong Jinsheng; Zhang Weijian; Chen Jinmei; Cai Chuanshu; Ke Chunlin; Chen Xiuying; Wu Bing; Guo Feibao

2009-01-01

Objective: To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods: Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs (DRR). Then the setup margins from CTV to PTV were calculated. By using self paired design, 22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes; Group B: the margins were aquired in this study. The difference were compared by Paired t-test or Wilcoxon signed-rank test. Results: The margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy ± 1449.6 cGy vs. 4310.2 cGy ± 1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82% ± 5.99% vs. 3.64% ± 4.70%; Z=-2.70, P=0.007). Conclusions: For patients with thoracic esophageal carcinoma who receive 3DCRT in author's department, the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis. (authors)

Anal wall sparing effect of an endorectal balloon in 3D conformal and intensity-modulated prostate radiotherapy

International Nuclear Information System (INIS)

Smeenk, Robert Jan; Lin, Emile N.J.Th. van; Kollenburg, Peter van; Kunze-Busch, Martina; Kaanders, Johannes H.A.M.

2009-01-01

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 78 Gy. 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 ≥20 Gy to ≥70 Gy (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 12 Gy in 3D-CRT and was 7.5 Gy 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.

Literature-based recommendations for treatment planning and execution in high-dose radiotherapy for lung cancer

International Nuclear Information System (INIS)

Senan, Suresh; De Ruysscher, Dirk; Giraud, Philippe; Mirimanoff, Rene; Budach, Volker

2004-01-01

Background and purpose: To review the literature on techniques used in high-dose radiotherapy of lung cancer in order to develop recommendations for clinical practice and for use in research protocols. Patients and methods: A literature search was performed for articles and abstracts that were considered both clinically relevant and practical to use. The relevant information was arbitrarily categorized under the following headings: patient positioning, CT scanning, incorporating tumour mobility, definition of target volumes, radiotherapy planning, treatment delivery, and scoring of response and toxicity. Results: Recommendations were made for each of the above steps from the published literature. Although most of the recommended techniques have yet to be evaluated in multicenter clinical trials, their use in high-dose radiotherapy to the thorax appears to be rational on the basis of current evidence. Conclusions: Recommendations for the clinical implementation of high-dose conformal radiotherapy for lung tumours were identified in the literature. Procedures that are still considered to be investigational were also highlighted

Skin markings in external radiotherapy by temporary tattooing with henna: Improvement of accuracy and increased patient comfort

International Nuclear Information System (INIS)

Wurstbauer, Karl; Sedlmayer, Felix; Kogelnik, H. Dieter

2001-01-01

Purpose: To guarantee invariable skin markings in patients undergoing a course of external radiotherapy, especially using conformal techniques. Cutaneous markings with henna also increase patient comfort, because washing and showering are allowed. Methods and Materials: Henna, a completely natural product, is a skin colorant with a history of 5,000 years. It is applied to the skin in the form of a paste. While drying, henna stains the superficial skin layers for several weeks, and the marked area can be exposed to water arbitrarily. In case of fading of the stain before the end of radiotherapy, the marking procedure can be repeated. From November 1998 until March 2000, we performed skin markings with henna in 158 patients with different tumor sites. The majority of patients received conformal radiotherapy techniques. All patients have been evaluated concerning durability of the markings, the required number of marking procedures per treatment course, and possible related side effects. Results: The median durability of henna staining is 23 days (range 12-48 days). On average, two marking procedures (range 1-4) are necessary for a patient treated with curative intent. Although washing and showering are freely permitted, no adverse cutaneous side effects (e.g., erythema, allergic reactions) have been observed. Conclusions: Skin marking by temporary tattooing with henna increases the accuracy of external radiotherapy. It yields stable and invariable markings for the entire course of radiotherapy and also increases the comfort of patients

Individualized margins in 3D conformal radiotherapy planning for lung cancer: analysis of physiological movements and their dosimetric impacts.

Science.gov (United States)

Germain, François; Beaulieu, Luc; Fortin, André

2008-01-01

In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage.

Individualized Margins in 3D Conformal Radiotherapy Planning for Lung Cancer: Analysis of Physiological Movements and Their Dosimetric Impacts

International Nuclear Information System (INIS)

Germain, Francois; Beaulieu, Luc; Fortin, Andre

2008-01-01

In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage

SU-F-P-52: A Meta-Analysis of Controlled Clinical Trials Comparing Elective Nodal Irradiation with Involved-Field Irradiation for Conformal Or Intensity-Modulated Radiotherapy in Patients with Esophageal Cancer

Energy Technology Data Exchange (ETDEWEB)

Bai, W; Zhang, R; Zhou, Z; Qiao, X [The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei (China)

2016-06-15

Purpose: To compare elective nodal irradiation with involved-field irradiation for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer by a metaanalysis. Methods: Wanfang, CNKI, VIP, CBM databases, PubMed, Embase and Cochrane Library were searched to identify the controlled clinical trials of elective nodal irradiation with involved-field irradiation for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer. The obtained data were analyzed using Stata 11.0. The difference between two groups was estimated by calculating the odds ratio (OR) with 95% confidence interval (95% CI). Results: A total of 12 controlled clinical trials involving 1095 esophageal cancer patients, which were selected according to inclusion and exclusion criteria, were included in this meta-analysis. The meta-analysis showed that the elective nodal irradiation group reduced the rates of out-field failure comparing with involved-field irradiation group (OR=3.727, P=0.007). However, the rates of ≥grades 3 acute radiation pneumonitis and esophagitis were significantly higher in the elective nodal irradiation group than in the involved-field irradiation group (OR=0.348, P=0.001, OR=0.385, P=0.000). 1-, 2-, 3-year local control rates (OR=0.966, P=0.837, OR=0.946, P=0.781; OR=0.732P=0.098) and 1-, 3-, 5-year survival rates were similar in the two groups ( OR=0.966, P=0.837; OR=0.946, P=0.781; OR=0.732, P=0.098; OR=0.952, P=0.756; OR=1.149, P=0.422; OR=0.768, P=0.120). It is the same with the rates of distant metastasis (OR=0.986, P=0.937). Conclusion: Compared with involved-field irradiation, the elective nodal irradiation can reduce the rates of out-field failure for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer. However, its advantage of local control and survival rates is not obvious and it increases the incidence

Aftereffect of radiotherapy of upper aero-digestive tracts in odontological care

International Nuclear Information System (INIS)

Schiochet, Luc

2010-01-01

In its first part, this thesis proposes a detailed presentation of the upper aero-digestive tract cancer. The author defines the cancerous process, describes anatomic aspects, and discusses epidemiological aspects (occurrence, mortality, survival, and epidemiological data in different countries). In the second part, the author discusses the role of radiotherapy and of dental surgery in taking a cancerous patient into care (general principles of radiotherapy, therapeutic options and choices, association of radiotherapy, chemotherapy and surgery). Principles of radiotherapy are then more precisely addressed: physical principles (X rays, gamma rays, electrons, neutrons, and protons), radioactivity doses, radiotherapy effect, main equipment, radiotherapy techniques (conformational or intensity-modulated radiotherapy, computed tomography, Cyberknife, external radiotherapy, brachytherapy). The third part addresses early oral-facial complications induced by radiotherapy: factors favouring these complications, nervous effects, effects on the blood system and on the skin, hyposialia and xerostomia, radio-induced mucositis of upper aero-digestive tracts. The next part addresses late effects: late cutaneous after-effects, late radio-mucositis, limitation of mouth opening, tooth decays, osteoradionecrosis. The last part addresses the role of the dental surgeon in taking into care a patient whose head and neck have been irradiated: role before irradiation, during irradiation, and after irradiation [fr

A Dosimetric Evaluation of Conventional Helmet Field Irradiation Versus Two-Field Intensity-Modulated Radiotherapy Technique

International Nuclear Information System (INIS)

Yu, James B.; Shiao, Stephen L.; Knisely, Jonathan

2007-01-01

Purpose: To compare dosimetric differences between conventional two-beam helmet field irradiation (external beam radiotherapy, EBRT) of the brain and a two-field intensity-modulated radiotherapy (IMRT) technique. Methods and Materials: Ten patients who received helmet field irradiation at our institution were selected for study. External beam radiotherapy portals were planned per usual practice. Intensity-modulated radiotherapy fields were created using the identical field angles as the EBRT portals. Each brain was fully contoured along with the spinal cord to the bottom of the C2 vertebral body. This volume was then expanded symmetrically by 0.5 cm to construct the planning target volume. An IMRT plan was constructed using uniform optimization constraints. For both techniques, the nominal prescribed dose was 3,000 cGy in 10 fractions of 300 cGy using 6-MV photons. Comparative dose-volume histograms were generated for each patient and analyzed. Results: Intensity-modulated radiotherapy improved dose uniformity over EBRT for whole brain radiotherapy. The mean percentage of brain receiving >105% of dose was reduced from 29.3% with EBRT to 0.03% with IMRT. The mean maximum dose was reduced from 3,378 cGy (113%) for EBRT to 3,162 cGy (105%) with IMRT. The mean percent volume receiving at least 98% of the prescribed dose was 99.5% for the conventional technique and 100% for IMRT. Conclusions: Intensity-modulated radiotherapy reduces dose inhomogeneity, particularly for the midline frontal lobe structures where hot spots occur with conventional two-field EBRT. More study needs to be done addressing the clinical implications of optimizing dose uniformity and its effect on long-term cognitive function in selected long-lived patients

IMRT and 3D conformal radiotherapy with or without elective nodal irradiation in locally advanced NSCLC. A direct comparison of PET-based treatment planning

International Nuclear Information System (INIS)

Fleckenstein, Jochen; Kremp, Katharina; Kremp, Stephanie; Palm, Jan; Ruebe, Christian

2016-01-01

The potential of intensity-modulated radiation therapy (IMRT) as opposed to three-dimensional conformal radiotherapy (3D-CRT) is analyzed for two different concepts of fluorodeoxyglucose positron emission tomography (FDG PET)-based target volume delineation in locally advanced non-small cell lung cancer (LA-NSCLC): involved-field radiotherapy (IF-RT) vs. elective nodal irradiation (ENI). Treatment planning was performed for 41 patients with LA-NSCLC, using four different planning approaches (3D-CRT-IF, 3D-CRT-ENI, IMRT-IF, IMRT-ENI). ENI included a boost irradiation after 50 Gy. For each plan, maximum dose escalation was calculated based on prespecified normal tissue constraints. The maximum prescription dose (PD), tumor control probability (TCP), conformal indices (CI), and normal tissue complication probabilities (NTCP) were analyzed. IMRT resulted in statistically significant higher prescription doses for both target volume concepts as compared with 3D-CRT (ENI: 68.4 vs. 60.9 Gy, p < 0.001; IF: 74.3 vs. 70.1 Gy, p < 0.03). With IMRT-IF, a PD of at least 66 Gy was achieved for 95 % of all plans. For IF as compared with ENI, there was a considerable theoretical increase in TCP (IMRT: 27.3 vs. 17.7 %, p < 0.00001; 3D-CRT: 20.2 vs. 9.9 %, p < 0.00001). The esophageal NTCP showed a particularly good sparing with IMRT vs. 3D-CRT (ENI: 12.3 vs. 30.9 % p < 0.0001; IF: 15.9 vs. 24.1 %; p < 0.001). The IMRT technique and IF target volume delineation allow a significant dose escalation and an increase in TCP. IMRT results in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels. (orig.) [de

Investigation of conformal and intensity-modulated radiation therapy techniques to determine the absorbed fetal dose in pregnant patients with breast cancer

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Öğretici, Akın, E-mail: akinogretici@gmail.com; Akbaş, Uğur; Köksal, Canan; Bilge, Hatice

2016-07-01

The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for breast cancers. An Alderson Rando phantom was chosen to simulate a pregnant patient with breast cancer who is receiving radiation therapy. This phantom was irradiated using the Varian Clinac DBX 600 system (Varian Medical System, Palo Alto, CA) linear accelerator, according to the standard treatment plans of both three-dimensional conformal radiation therapy (3-D CRT) and IMRT techniques. Thermoluminescent dosimeters were used to measure the irradiated phantom's virtually designated uterus area. Thermoluminescent dosimeter measurements (in the phantom) revealed that the mean cumulative fetal dose for 3-D CRT is 1.39 cGy and for IMRT it is 8.48 cGy, for a pregnant breast cancer woman who received radiation treatment of 50 Gy. The fetal dose was confirmed to increase by 70% for 3-D CRT and 40% for IMRT, if it is closer to the irradiated field by 5 cm. The mean fetal dose from 3-D CRT is 1.39 cGy and IMRT is 8.48 cGy, consistent with theoretic calculations. The IMRT technique causes the fetal dose to be 5 times more than that of 3-D CRT. Theoretic knowledge concerning the increase in the peripheral doses as the measurements approached the beam was also practically proven.

Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

International Nuclear Information System (INIS)

Tamaki, Tomoaki; Nakano, Takashi; Ohno, Tatsuya; Kiyohara, Hiroki; Noda, Shin-ei; Ohkubo, Yu; Ando, Ken; Wakatsuki, Masaru; Kato, Shingo; Kamada, Tadashi

2013-01-01

Recurrences of cervical cancer after definitive radiotherapy often occur at common iliac or para-aortic lymph nodes as marginal lymph node recurrences. Patients with these recurrences have a chance of long-term survival by optimal re-treatment with radiotherapy. However, the re-irradiation often overlaps the initial and the secondary radiotherapy fields and can result in increased normal tissue toxicities in the bowels or the stomach. Carbon-ion radiotherapy, a form of particle beam radiotherapy using accelerated carbon ions, offers more conformal and sharp dose distribution than X-ray radiotherapy. Therefore, this approach enables the delivery of high radiation doses to the target while sparing its surrounding normal tissues. Marginal lymph node recurrences in common iliac lymph nodes after radiotherapy were treated successfully by carbon-ion radiotherapy in two patients. These two patients were initially treated with a combination of external beam radiotherapy and intracavitary and interstitial brachytherapy. However, the diseases recurred in the lymph nodes near the border of the initial radiotherapy fields after 22 months and 23 months. Because re-irradiation with X-ray radiotherapy may deliver high doses to a section of the bowels, carbon-ion radiotherapy was selected to treat the lymph node recurrences. A total dose of 48 Gy (RBE) in 12 fractions over 3 weeks was given to the lymph node recurrences, and the tumors disappeared completely with no severe acute toxicities. The two patients showed no evidence of disease for 75 months and 63 months after the initial radiotherapy and for 50 months and 37 months after the carbon-ion radiotherapy, respectively. No severe late adverse effects are observed in these patients. The two presented cases suggest that the highly conformal dose distribution of carbon-ion radiotherapy may be beneficial in the treatment of marginal lymph node recurrences after radiotherapy. In addition, the higher biological effect of carbon

Significance of breast boost volume changes during radiotherapy in relation to current clinical interobserver variations

International Nuclear Information System (INIS)

Hurkmans, Coen; Admiraal, Marjan; Sangen, Maurice van der; Dijkmans, Ingrid

2009-01-01

Background and purpose: Nowadays, many departments introduce CT images for breast irradiation techniques, aiming to obtain a better accuracy in the definition of the relevant target volumes. However, the definition of the breast boost volume based on CT images requires further investigation, because it may not only vary between observers, but it may also change during the course of treatment. This study aims to quantify the variability of the CT based visible boost volume (VBV) during the course of treatment in relation to the variability between observers. Materials and methods: Ten patients with stage T1-2 invasive breast cancer treated with breast conservative surgery and post surgical radiotherapy were included in this study. In addition to the regular planning CT which is obtained several days prior to radiotherapy, three additional CT scans were acquired 3, 5 and 7 weeks after the planning CT scan. Four radiation oncologists delineated the VBV in all scans. Conformity of the delineations was analysed both between observers, and between scans taken at different periods of the radiotherapy treatment. Results: The VBV averaged over all patients decreased during the course of the treatment from an initial 40 cm 3 to 28 cm 3 , 27 cm 3 and 25 cm 3 after 3, 5 and 7 weeks, respectively. Assuming the VBV to be spherical, this corresponds to a reduction in diameter of 5-6 mm. More detailed analysis revealed that this reduction was more pronounced when radiotherapy started within 30 days after surgery. These boost volume changes over time were found to be significant (p = 0.02) even in the presence of interobserver variations. Moreover, the conformity index (CI) for the volume changes was of the same magnitude as the conformity index for the interobserver variation (0.25 and 0.31, respectively). Conclusions: Breast boost volume variations during a course of radiotherapy are significant in relation to current clinical interobserver variations. This is an important

Factors Influencing Neurocognitive Outcomes in Young Patients With Benign and Low-Grade Brain Tumors Treated With Stereotactic Conformal Radiotherapy

International Nuclear Information System (INIS)

Jalali, Rakesh; Mallick, Indranil; Dutta, Debnarayan

2010-01-01

Purpose: To present the effect of radiotherapy doses to different volumes of normal structures on neurocognitive outcomes in young patients with benign and low-grade brain tumors treated prospectively with stereotactic conformal radiotherapy (SCRT). Methods and Materials: Twenty-eight patients (median age, 13 years) with residual/progressive brain tumors (10 craniopharyngioma, 8 cerebellar astrocytoma, 6 optic pathway glioma and 4 cerebral low-grade glioma) were treated with SCRT to a dose of 54 Gy in 30 fractions over 6 weeks. Prospective neuropsychological assessments were done at baseline before RT and at subsequent follow-up examinations. The change in intelligence quotient (IQ) scores was correlated with various factors, including dose-volume to normal structures. Results: Although the overall mean full-scale IQ (FSIQ) at baseline before RT remained unchanged at 2-year follow-up after SCRT, one third of patients did show a >10% decline in FSIQ as compared with baseline. Logistic regression analysis demonstrated that patients aged 10% drop in FSIQ than older patients (53% vs. 10%, p = 0.03). Dosimetric comparison in patients showing a >10% decline vs. patients showing a 43.2 Gy to >13% of volume of the left temporal lobe were the ones to show a significant drop in FSIQ (p = 0.048). Radiotherapy doses to other normal structures, including supratentorial brain, right temporal lobe, and frontal lobes, did not reveal any significant correlation. Conclusion: Our prospectively collected dosimetric data show younger age and radiotherapy doses to left temporal lobe to be predictors of neurocognitive decline, and may well be used as possible dose constraints for high-precision radiotherapy planning.

Study on the possibility of using a 60 Co therapeutical unity in Intensity Modulated Radiotherapy (IMRT)

International Nuclear Information System (INIS)

Dantas, Samuel Cesar

2009-06-01

With the increasing advances in complex treatment techniques, there is a tendency to obtain more sophisticated equipment to deliver the dose. The use of 3D conformal radiotherapy is now routine in many radiotherapy facilities as well as the utilization of intensity modulated radiotherapy (IMRT). Both are usually implemented using linear accelerators equipped with multi leaves collimators, which create the conformity and the fluence distributions required. However, the complexity of increasingly sophisticated equipment, such as linear accelerators, requires a frequent quality control of their operation, as well as a detailed and constant maintenance. Even carrying out these procedures, the accelerators may present technical problems interrupting for a long time a treatment using the IMRT technique. Despite the clear practical and technological advantages that linear accelerators have on 60 Co irradiators, these devices occupy an important place in radiotherapy, mainly due to the low cost of equipment installation and maintenance when compared to those required by accelerators. Many radiotherapy facilities that work with IMRT have tele therapeutic isocentric 60 Co units. In principle, such equipment would be able to be used for treatment with IMRT using compensating blocks to modulate the beam. This study investigates this possibility and shows that it is feasible. The comparison of treatment plans of a head-and-neck cancer and other of a cancer of the central nervous system, based on a 60 Co irradiator and a Linac 2300 C/D, presented advantages for the 60 Co irradiator. Furthermore; the delivery of dose obtained with the two systems showed themselves equivalent when compared to their respective plans. (author)

Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

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Poli, Ana Paula Diniz Fortuna, E-mail: anapaulafortuna@yahoo.com.br [Universidade Estadual de Campinas (CAISM/UNICAMP), Campinas, SP (Brazil). Centro de Atencao Integrada a Saude da Mulher. Divisao de Radioterapia; Dias, Rodrigo Souza; Giordani, Adelmo Jose; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Divisao de Radioterapia

2016-01-15

Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation (p = 0.037). A baseline rectal volume superior to 70 cm{sup 3} had a significant influence on the prostate motion in the anteroposterior direction (p = 0.045). Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm{sup 3}. Therefore, the treatment of patients with a rectal volume > 70 cm{sup 3} should be re-planned with appropriate rectal preparation. Keywords: Rectal volume; Prostate cancer; Three-dimensional conformal radiotherapy. (author)

Breast radiotherapy in the lateral decubitus position: A technique to prevent lung and heart irradiation

International Nuclear Information System (INIS)

Campana, Francois; Kirova, Youlia M.; Rosenwald, Jean-Claude; Dendale, Remi; Vilcoq, Jacques R.; Dreyfus, Helene; Fourquet, Alain

2005-01-01

Purpose: To present an original technique for breast radiotherapy, with the aim of limiting lung and heart irradiation, satisfying quality assurance criteria. Methods and Material: An original radiotherapy technique for breast irradiation has been developed at the Institute Curie in January 1996. It consists of isocentric breast irradiation in the lateral decubitus position (isocentric lateral decubitus [ILD]). This technique is indicated for voluminous or pendulous breasts needing breast irradiation only. Thin carbon fiber supports and special patient positioning devices have been developed especially for this technique. In vivo measurements were performed to check the dose distribution before the routine use of the technique. Results: ILD has been successfully implemented in routine practice, and 500 patients have been already treated. Breast radiotherapy is performed using a dose of 50 Gy at ICRU point in 25 fractions. ILD shows good homogeneity of the dose in breast treatment volume, treatment fields are perpendicular to the skin ensuring its protection, and extremely low dose is delivered to the underlying lung and heart. Conclusion: In cases of voluminous breasts or patients with a history of lung and heart disease, our technique provides several advantages over the conventional technique with opposing tangential fields. This technique improves the dose homogeneity according to the ICRU recommendations

Physics aspects of recent and future concepts in radiotherapy

International Nuclear Information System (INIS)

Georg, D.

2001-01-01

Full text: The development of 3-D conformal radiotherapy (3D-CRT), in which the high dose volume matches as closely as possible the target volume and avoids therefore normal tissue irradiation as far as possible, has been a major theme in radiotherapy for improving the therapeutic window. Conformal radiotherapy is not a new concept but only the technological improvements of the last decade allow its clinical implementation. More recent and advanced forms of 3D-CRT are intensity modulated radiotherapy (IMRT) and stereotactic radiotherapy (SRT). IMRT uses an additional degree of freedom to achieve a new class of conformation: the variation of the primary beam intensity. SRT is based on a three dimensional stereotactic coordinate system which is correlated with the patient and the treatment facility through modern imaging technology. IMRT and SRT are related by common features, e.g. high dose gradients and small fields which require a high geometric precision. A high dosimetric and geometric precision can only be based on a detailed knowledge of the patient specific anatomy. Therefore, IMRT and SRT need to underlie multi-modality imaging studies. Both IMRT and SRT utilize photon beams and multiple field arrangements which increase the volumes of healthy tissue receiving low doses. Photons have a low selectivity along the beam direction implying that the sharp dose gradients are to be compromised. The increased low dose volume as well as the low selectivity of photon beams can be over-come by using proton or ions. Brachytherapy, a form of radiotherapy where encapsuled radioactive sources are placed directly in or in the vicinity of the tumor, is by definition conformal. Endovascular brachytherapy has become a promising new field in radiotherapy for the prevention of (re)stenosis after angioplasty. Although many clinical trials have been performed during the last years specific aspects related to endovascular brachytherapy have not been addressed clearly, such as the

Preliminary results of three-dimensional conformal radiotherapy for non-small cell lung cancer

International Nuclear Information System (INIS)

Wang Yingjie; Wang Luhua; Wang Xin; Feng Qinfu; Zhang Hongxing; Xiao Zefen; Yin Weibo

2005-01-01

Objective: To evaluate the therapeutic effects and complications of three-dimensional conformal radiotherapy (3DCRT) for non-small cell lung cancer (NSCLC). Methods: Between March 1999 and September 2003, 91 NSCLC patients treated with 3DCRT were reviewed at the Cancer Hospital, Chinese Academy of Medical Sciences. This patient cohort consisted of 73 men and 18 women. The median age was 66 years. Radio-therapy was delivered at 2 Gy fraction, 5 fractions per week. The median total dose was 60 Gy. Results: With a median follow-up time of 17 months, the response rate after 3DCRT was 57.1%, with complete remission 11.0% (10/91) and partial remission 46.2%(42/91). The median survival time (MST) was 16 months, with 1- and 2- year overall survivals (OS) of 67.0% and 32.6%, 1- and 2-year local progression free survivals (LPFS) of 82.6% and 53.0%, respectively. The independent adverse prognostic factors by univariate analysis and multivariate analysis was weight loss ≥5%. Grade 2 acute radiation pneumonitis was observed in 2 patients and grade 3 in 4 patients. Late lung injury developed in 1 patient with grade 2, 1 patient with grade 3, respectively. Acute radiation esophagitis was observed in 8 patients with grade 2. Acute grade 2 hematologic toxicity developed in 5 patients. Conclusions: 3DCRT was feasible in the treatment of NSCLC with good immediate tumor response and acceptable normal tissue complication. The total dose may potentially be increased. (authors)

A singular value decomposition linear programming (SVDLP) optimization technique for circular cone based robotic radiotherapy

Science.gov (United States)

Liang, Bin; Li, Yongbao; Wei, Ran; Guo, Bin; Xu, Xuang; Liu, Bo; Li, Jiafeng; Wu, Qiuwen; Zhou, Fugen

2018-01-01

With robot-controlled linac positioning, robotic radiotherapy systems such as CyberKnife significantly increase freedom of radiation beam placement, but also impose more challenges on treatment plan optimization. The resampling mechanism in the vendor-supplied treatment planning system (MultiPlan) cannot fully explore the increased beam direction search space. Besides, a sparse treatment plan (using fewer beams) is desired to improve treatment efficiency. This study proposes a singular value decomposition linear programming (SVDLP) optimization technique for circular collimator based robotic radiotherapy. The SVDLP approach initializes the input beams by simulating the process of covering the entire target volume with equivalent beam tapers. The requirements on dosimetry distribution are modeled as hard and soft constraints, and the sparsity of the treatment plan is achieved by compressive sensing. The proposed linear programming (LP) model optimizes beam weights by minimizing the deviation of soft constraints subject to hard constraints, with a constraint on the l 1 norm of the beam weight. A singular value decomposition (SVD) based acceleration technique was developed for the LP model. Based on the degeneracy of the influence matrix, the model is first compressed into lower dimension for optimization, and then back-projected to reconstruct the beam weight. After beam weight optimization, the number of beams is reduced by removing the beams with low weight, and optimizing the weights of the remaining beams using the same model. This beam reduction technique is further validated by a mixed integer programming (MIP) model. The SVDLP approach was tested on a lung case. The results demonstrate that the SVD acceleration technique speeds up the optimization by a factor of 4.8. Furthermore, the beam reduction achieves a similar plan quality to the globally optimal plan obtained by the MIP model, but is one to two orders of magnitude faster. Furthermore, the SVDLP

A singular value decomposition linear programming (SVDLP) optimization technique for circular cone based robotic radiotherapy.

Science.gov (United States)

Liang, Bin; Li, Yongbao; Wei, Ran; Guo, Bin; Xu, Xuang; Liu, Bo; Li, Jiafeng; Wu, Qiuwen; Zhou, Fugen

2018-01-05

With robot-controlled linac positioning, robotic radiotherapy systems such as CyberKnife significantly increase freedom of radiation beam placement, but also impose more challenges on treatment plan optimization. The resampling mechanism in the vendor-supplied treatment planning system (MultiPlan) cannot fully explore the increased beam direction search space. Besides, a sparse treatment plan (using fewer beams) is desired to improve treatment efficiency. This study proposes a singular value decomposition linear programming (SVDLP) optimization technique for circular collimator based robotic radiotherapy. The SVDLP approach initializes the input beams by simulating the process of covering the entire target volume with equivalent beam tapers. The requirements on dosimetry distribution are modeled as hard and soft constraints, and the sparsity of the treatment plan is achieved by compressive sensing. The proposed linear programming (LP) model optimizes beam weights by minimizing the deviation of soft constraints subject to hard constraints, with a constraint on the l 1 norm of the beam weight. A singular value decomposition (SVD) based acceleration technique was developed for the LP model. Based on the degeneracy of the influence matrix, the model is first compressed into lower dimension for optimization, and then back-projected to reconstruct the beam weight. After beam weight optimization, the number of beams is reduced by removing the beams with low weight, and optimizing the weights of the remaining beams using the same model. This beam reduction technique is further validated by a mixed integer programming (MIP) model. The SVDLP approach was tested on a lung case. The results demonstrate that the SVD acceleration technique speeds up the optimization by a factor of 4.8. Furthermore, the beam reduction achieves a similar plan quality to the globally optimal plan obtained by the MIP model, but is one to two orders of magnitude faster. Furthermore, the SVDLP

A strategy to correct for intrafraction target translation in conformal prostate radiotherapy: Simulation results

International Nuclear Information System (INIS)

Keall, P. J.; Lauve, A. D.; Hagan, M. P.; Siebers, J. V.

2007-01-01

A strategy is proposed in which intrafraction internal target translation is corrected for by repositioning the multileaf collimator position aperture to conform to the new target pose in the beam projection, and the beam monitor units are adjusted to account for the change in the geometric relationship between the target and the beam. The purpose of this study was to investigate the dosimetric stability of the prostate and critical structures in the presence of internal target translation using the dynamic compensation strategy. Twenty-five previously treated prostate cancer patients were replanned using a four-field conformal technique to deliver 72 Gy to 95% of the planning target volume (PTV). Internal translation was introduced by displacing the prostate PTV (no rotation or deformation was considered). Thirty-six randomly selected isotropic displacements of magnitude 0.5, 1.0, 1.5 and 2.0 cm were sampled for each patient, for a total of 3600 errors. Due to their anatomic relation to the prostate, the rectum and bladder contours were also moved with the same magnitude and direction as the prostate. The dynamic compensation strategy was used to correct each of these errors by conforming the beam apertures to the new target pose and adjusting the monitor units using inverse-square and off-axis factor corrections. The dynamic compensation strategy plans were then compared to the original treatment plans via dose-volume histogram (DVH) analysis. Changes of more than 5% of the prescription dose (3.6 Gy) were deemed clinically significant. Compared to the original treatment plans, the dynamic compensation strategy produced small discrepancies in isodose distributions and DVH analyses for all structures considered apart from the femoral heads. These differences increased with the magnitude of the internal motion. Coverage of the PTV was excellent: D 5 , D 95 , and D mean were not increased or decreased by more than 5% of the prescription dose for any of the 3600

Setup accuracy of stereoscopic X-ray positioning with automated correction for rotational errors in patients treated with conformal arc radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Soete, Guy; Verellen, Dirk; Tournel, Koen; Storme, Guy

2006-01-01

We evaluated setup accuracy of NovalisBody stereoscopic X-ray positioning with automated correction for rotational errors with the Robotics Tilt Module in patients treated with conformal arc radiotherapy for prostate cancer. The correction of rotational errors was shown to reduce random and systematic errors in all directions. (NovalisBody TM and Robotics Tilt Module TM are products of BrainLAB A.G., Heimstetten, Germany)

Conformal radiation therapy of localized prostate cancer: acute tolerance and early evaluation of effectiveness

International Nuclear Information System (INIS)

Zierhut, D.; Flentje, M.; Sroka-Perez, G.; Rudat, V.; Engenhart-Cabillic, R.; Wannenmacher, M.

1997-01-01

Aim: In a prospective trial early effectiveness and acute toxicity of conformal 3D-planned radiotherapy for localized prostate cancer was quantified using dose-volume-histogramms and evaluated with respect of treatment technique. Results: Eleven patients (of 32) had none, 15 mild (RTOG grade 1) and 6 moderate symptoms (RTOG grade 2, mainly diarrhoea, dysuria and polyuria). Acute complications leading to treatment interruption did not occur. In 16 patients symptoms disappeared within 6 weeks after radiotherapy. Only 2 men had symptoms which lasted longer than 3 months and were endoscopically examined. Up to now no late complications were detected. Incidence and severity of toxicity was significantly (p [de

Advances in conformal radiotherapy using Monte Carlo Code to design new IMRT and IORT accelerators and interpret CT numbers

CERN Document Server

Wysocka-Rabin, A

2013-01-01

The introductory chapter of this monograph, which follows this Preface, provides an overview of radiotherapy and treatment planning. The main chapters that follow describe in detail three significant aspects of radiotherapy on which the author has focused her research efforts. Chapter 2 presents studies the author worked on at the German National Cancer Institute (DKFZ) in Heidelberg. These studies applied the Monte Carlo technique to investigate the feasibility of performing Intensity Modulated Radiotherapy (IMRT) by scanning with a narrow photon beam. This approach represents an alternative to techniques that generate beam modulation by absorption, such as MLC, individually-manufactured compensators, and special tomotherapy modulators. The technical realization of this concept required investigation of the influence of various design parameters on the final small photon beam. The photon beam to be scanned should have a diameter of approximately 5 mm at Source Surface Distance (SSD) distance, and the penumbr...

Hypo fractionated conformal irradiation of patients with malignant glioma

International Nuclear Information System (INIS)

Aboziada, M.A.; Abo-Kresha, A.E.

2012-01-01

Purpose: The aim of the study is to evaluate the effect of a conformal irradiation in short fractionation scheme of 49.5 Gy in 15 fractions in an overall time of 3 weeks, in terms of overall survival (OAS) and progression free survival (PFS) rates in brain glioma patients. Patients and methods: A prospective study was conducted on 54 brain glioma patients and was carried out in the Radiation Oncology Department, South Egypt Cancer Institute, Assiut University during the period from April 2006 till June 2009. Patients were treated by hypo fractionated conformal irradiation (49.5 Gy/15 fractions/3 weeks). Results: The median follow up was 23 months (range: 9-39 months). Two-year OAS and PFS rates were 68% and 60%, respectively. In univariate analysis, age > 50 years, poor performance status [Karnofasky score of >40- 50 years and glioblastoma pathology were the only independent prognostic factors that were associated with poor OAS (p = 0.003 and p = 0.004, respectively), and PFS (p = 0.027 and p = 0.011, respectively). Conclusion: Hypo fractionated conformal radiotherapy was as effective as the conventional radiotherapy, with time sparing for patients, and for radiation oncology centers. Hypo fractionated radiotherapy may be considered the radiotherapy regimen of choice in clinical practice for patients with gliomas

Comparison of mucous and cutaneous toxicity of IMRT and of conventional radiotherapy associated with cetuximab; Comparaison de la toxicite muqueuse et cutanee de la RCMI et de la radiotherapie classique associee au cetuximab

Energy Technology Data Exchange (ETDEWEB)

Kreps, S.; Tamby, E.; Dessard Diana, B.; Berges, O.; Botti, M.; Deberne, M.; Henni, M.; Durdux, C.; Housset, M.; Giraud, P. [Hopital europeen Georges-Pompidou, Paris (France)

2011-10-15

The authors report a retrospective assessment of acute, cutaneous and mucous toxicity resulting from an association of cetuximab and conventional conformational radiotherapy, and from an intensity-modulated conformational radiotherapy (IMRT). Seven patients presenting nasopharyngeal, oropharyngeal or hypopharyngeal tumours have been irradiated with intensity modulation, and seven without. It appears that the association of cetuximab and radiotherapy is not well tolerated and requires a close monitoring. Intensity-modulated radiotherapy allows a significant reduction of dose and of toxicity. However, mucous toxicity remains significant. Short communication

Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer.

Directory of Open Access Journals (Sweden)

Xin Ming

Full Text Available To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT, intensity-modulated radiotherapy (IMRT, or volumetric modulated arc therapy (VMAT at our institution in the past seven years.A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2% with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.

Craniospinal irradiation techniques

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Scarlatescu, Ioana, E-mail: scarlatescuioana@gmail.com; Avram, Calin N. [Faculty of Physics, West University of Timisoara, Bd. V. Parvan 4, 300223 Timisoara (Romania); Virag, Vasile [County Hospital “Gavril Curteanu” - Oradea (Romania)

2015-12-07

In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

Rotational radiotherapy for prostate cancer in clinical practice

DEFF Research Database (Denmark)

Aznar, Marianne C; Petersen, Peter Meidahl; Logadottir, Ashildur

2010-01-01

Radiotherapy is the standard treatment in locally advanced prostate cancer. The latest technological improvement is modulated rotational radiotherapy, where one single rotation of the treatment machine is used to conform the dose delivery to the target and spare organs at risk, requiring less than...

Assessment of renal function after conformal radiotherapy and intensity-modulated radiotherapy by functional 1H-MRI and 23Na-MRI

International Nuclear Information System (INIS)

Haneder, S.; Michaely, H.J.; Schoenberg, S.O.; Konstandin, S.; Schad, L.R.; Siebenlist, K.; Wertz, H.; Wenz, F.; Lohr, F.; Boda-Heggemann, J.

2012-01-01

Purpose: Adjuvant radiochemotherapy (RCHT) improves survival of patients with locally advanced gastric cancer. Conventional three-dimensional conformal radiotherapy (3D-CRT) results in ablative doses to a significant amount of the left kidney, while image-guided intensity-modulated radiotherapy (IG-IMRT) provides excellent target coverage with improved kidney sparing. Few long-term results on IMRT for gastric cancer, however, have been published. Functional magnetic resonance imaging (fMRI) at 3.0 T including blood oxygenation-level dependent (BOLD) imaging, diffusion-weighted imaging (DWI) and, for the first time, 23 Na imaging was used to evaluate renal status after radiotherapy with 3D-CRT or IG-IMRT. Patients and methods Four disease-free patients (2 after 3D-CRT and 2 after IMRT; FU for all patients > 5 years) were included in this feasibility study. Morphological sequences, axial DWI images, 2D-gradient echo (GRE)-BOLD images, and 23 Na images were acquired. Mean values/standard deviations for ( 23 Na), the apparent diffusion coefficient (ADC), and R2 * values were calculated for the upper/middle/lower parts of both kidneys. Corticomedullary 23 Na-concentration gradients were determined. Results: Surprisingly, IG-IMRT patients showed no morphological alterations and no statistically significant differences of ADC and R2 * values in all renal parts. Values for mean corticomedullary 23 Na-concentration matched those for healthy volunteers. Results were similar in 3D-CRT patients, except for the cranial part of the left kidney. This was atrophic and presented significantly reduced functional parameters (p = 0.001 - p = 0.033). Reduced ADC values indicated reduced cell density and reduced extracellular space. Cortical and medullary R2 * values of the left cranial kidney in the 3D-CRT group were higher, indicating more deoxygenated hemoglobin due to reduced blood flow/oxygenation. ( 23 Na) of the renal cranial parts in the 3D-CRT group was significantly reduced

Radiotherapy in bladder cancer

International Nuclear Information System (INIS)

Rozan, R.

1992-01-01

In 1992, the problem of the vesical radiotherapy is not resolved. The author presents the situation and the different techniques of radiotherapy in bladder cancers: external radiotherapy, only and associated with surgery, interstitial curietherapy and non-classical techniques as per operative radiotherapy, neutron therapy and concurrent radiotherapy with chemotherapy. In order to compare their efficiency, the five-year survival are given in all cases.(10 tabs)

Estimation of the incidence of late bladder and rectum complications after high-dose (70-78 Gy) conformal radiotherapy for prostate cancer, using dose-volume histograms

International Nuclear Information System (INIS)

Boersma, Liesbeth J.; Brink, Mandy van den; Bruce, Allison M.; Shouman, Tarek; Gras, Luuk; Velde, Annet te; Lebesque, Joos V.

1998-01-01

Purpose: To investigate whether Dose-Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer. Methods and Materials: DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (>6 months) GI and GU complications was classified using the RTOG/EORTC and the SOMA/LENT scoring system. In addition, GI complications were divided in nonsevere and severe (requiring one or more laser treatments or blood transfusions) rectal bleeding. The median follow-up time was 24 months. We investigated whether rectal and bladder wall volumes, irradiated to various dose levels, correlated with the observed actuarial incidences of GI and GU complications, using volume as a continuous variable. Subsequently, for each dose level in the DVH, the rectal wall volumes were dichotomized using different volumes as cutoff levels. The impact of the total radiation dose, and the maximum radiation dose in the rectal and bladder wall was analyzed as well. Results: The actuarial incidence at 2 years for GI complications ≥Grade II was 14% (RTOG/EORTC) or 20% (SOMA/LENT); for GU complications ≥Grade III 8% (RTOG/EORTC) or 21% (SOMA/LENT). Neither for GI complications ≥Grade II (RTOG/EORTC or SOMA/LENT), nor for GU complications ≥Grade III (RTOG/EORTC or SOMA/LENT), was a significant correlation found between any of the DVH parameters and the actuarial incidence of complications. For severe rectal bleeding (actuarial incidence at 2 years 3%), four consecutive volume cutoff levels were found, which significantly discriminated between high and low risk. A trend was observed that a total radiation dose ≥ 74 Gy (or a maximum radiation dose in the rectal wall >75 Gy) resulted in a higher incidence of severe rectal bleeding (p

Effectiveness of different rescanning techniques for scanned proton radiotherapy in lung cancer patients

Science.gov (United States)

Engwall, E.; Glimelius, L.; Hynning, E.

2018-05-01

Non-small cell lung cancer (NSCLC) is a tumour type thought to be well-suited for proton radiotherapy. However, the lung region poses many problems related to organ motion and can for actively scanned beams induce severe interplay effects. In this study we investigate four mitigating rescanning techniques: (1) volumetric rescanning, (2) layered rescanning, (3) breath-sampled (BS) layered rescanning, and (4) continuous breath-sampled (CBS) layered rescanning. The breath-sampled methods will spread the layer rescans over a full breathing cycle, resulting in an improved averaging effect at the expense of longer treatment times. In CBS, we aim at further improving the averaging by delivering as many rescans as possible within one breathing cycle. The interplay effect was evaluated for 4D robustly optimized treatment plans (with and without rescanning) for seven NSCLC patients in the treatment planning system RayStation. The optimization and final dose calculation used a Monte Carlo dose engine to account for the density heterogeneities in the lung region. A realistic treatment delivery time structure given from the IBA ScanAlgo simulation tool served as basis for the interplay evaluation. Both slow (2.0 s) and fast (0.1 s) energy switching times were simulated. For all seven studied patients, rescanning improves the dose conformity to the target. The general trend is that the breath-sampled techniques are superior to layered and volumetric rescanning with respect to both target coverage and variability in dose to OARs. The spacing between rescans in our breath-sampled techniques is set at planning, based on the average breathing cycle length obtained in conjunction with CT acquisition. For moderately varied breathing cycle lengths between planning and delivery (up to 15%), the breath-sampled techniques still mitigate the interplay effect well. This shows the potential for smooth implementation at the clinic without additional motion monitoring equipment.

Comparison of mucous and cutaneous toxicity of IMRT and of conventional radiotherapy associated with cetuximab

International Nuclear Information System (INIS)

Kreps, S.; Tamby, E.; Dessard Diana, B.; Berges, O.; Botti, M.; Deberne, M.; Henni, M.; Durdux, C.; Housset, M.; Giraud, P.

2011-01-01

The authors report a retrospective assessment of acute, cutaneous and mucous toxicity resulting from an association of cetuximab and conventional conformational radiotherapy, and from an intensity-modulated conformational radiotherapy (IMRT). Seven patients presenting nasopharyngeal, oropharyngeal or hypopharyngeal tumours have been irradiated with intensity modulation, and seven without. It appears that the association of cetuximab and radiotherapy is not well tolerated and requires a close monitoring. Intensity-modulated radiotherapy allows a significant reduction of dose and of toxicity. However, mucous toxicity remains significant. Short communication

A comparison of swallowing dysfunction after three-dimensional conformal and intensity-modulated radiotherapy. A systematic review by the Italian Head and Neck Radiotherapy Study Group

International Nuclear Information System (INIS)

Ursino, Stefano; Morganti, Riccardo; Cristaudo, Agostino; Paiar, Fabiola; D'Angelo, Elisa; Lohr, Frank; Mazzola, Rosario; Merlotti, Anna; Russi, Elvio Grazioso; Musio, Daniela; Alterio, Daniela; Bacigalupo, Almalina

2017-01-01

Dysphagia is one of the most important treatment-related side effects in head and neck cancer (HNC), as it can lead to severe life-threating complications such as aspiration pneumonia and malnutrition. Intensity-modulated radiotherapy (IMRT) could reduce swallowing dysfunction by producing a concave dose distribution and reducing doses to the swallowing-related organs at risk (SWOARs). The aim of this study was to review the current literature in order to compare swallowing outcomes between IMRT and three-dimensional conformal radiotherapy (3DCRT). A search was conducted in the PubMed and Embase databases to identify studies on swallowing outcomes, both clinically and/or instrumentally assessed, after 3DCRT and IMRT. Dysphagia-specific quality of life and objective instrumental data are summarized and discussed. A total of 262 papers were retrieved from the searched databases. An additional 23 papers were retrieved by hand-searching the reference lists. Ultimately, 22 papers were identified which discussed swallowing outcomes after 3DCRT and IMRT for HNC. No outcomes from randomized trials were identified. Despite several methodological limitations, reports from the current literature seem to suggest better swallowing outcomes with IMRT compared to 3DCRT. Further improvements are likely to result from the increased use of IMRT plans optimized for SWOAR sparing. (orig.) [de

Comparação entre os volumes pulmonares irradiados com técnica bidimensional e tridimensional conformada na radioterapia de pacientes com tumores de pulmão localmente avançados Comparison between irradiated lung volumes with two-dimensional and three-dimensional conformal radiotherapy techniques for locally advanced lung cancer

Directory of Open Access Journals (Sweden)

Heloisa de Andrade Carvalho

2009-10-01

Full Text Available OBJETIVO: Comparar e quantificar os volumes pulmonares irradiados utilizando planejamentos bidimensional (2D e tridimensional (3D conformado na radioterapia de tumores de pulmão. MATERIAIS E MÉTODOS: Em 27 pacientes portadores de câncer de pulmão foi feito planejamento 3D e outro correspondente em 2D. As doses prescritas variaram de 45 a 66 Gy. Foram avaliadas as doses no volume alvo planejado (PTV, volume tumoral macroscópico (GTV e pulmões (volume de pulmão que recebe 20 Gy ou 30 Gy - V20 e V30, respectivamente, e dose média. Os órgãos de risco adjacentes (medula espinhal, esôfago e coração receberam doses abaixo dos limites de tolerância. RESULTADOS: O GTV variou de 10,5 a 1.290,0 cm³ (média de 189,65 cm³. Nos planejamentos 2D foi utilizado, em média, um total de 59,33 campos, e nos planejamentos 3D, 75,65 campos. Em todas as situações analisadas houve significante (p OBJECTIVE: To compare and quantify irradiated lung volumes using two-dimensional (2D and three-dimensional (3D conformal planning for radiotherapy in the treatment of lung cancer. MATERIALS AND METHODS: 2D and 3D conformal radiotherapy plannings were performed for 27 patients with lung cancer. Prescribed doses ranged from 45 to 66 Gy. The analysis covered the doses to planning target volume (PTV, gross tumor volume (GTV and lungs (lung volume receiving 20 Gy or 30 Gy - V20 and V30, respectively, and mean dose. The doses to adjacent organs at risk (spinal cord, esophagus and heart were maintained below the tolerance limits. RESULTS: GTV ranged from 10.5 to 1,290.0 cm³ (mean, 189.65 cm³. On average, a total of 59.33 fields were utilized in the 2D planning and 75.65 fields in the 3D planning. Lung volumes were significantly preserved (P < 0.05 with the 3D conformal planning in all the evaluated cases, with about 15% decrease in the irradiated lung volumes. Lungs without tumor were most benefited from this technique. CONCLUSION: 3D radiotherapy allowed a better

External beam radiotherapy (EBRT) techniques used in breast cancer treatment to reduce cardiac exposure

International Nuclear Information System (INIS)

Fung, Esther; Hendry, Julie

2013-01-01

Radiotherapy in breast cancer treatment has been shown to reduce local recurrence and improve survival rates. However, there is a concern that breast radiotherapy can cause an increase in cardiac mortality, particularly in patients being treated for left-sided breast cancer. This review aims to investigate how cardiac exposure is minimised in breast radiotherapy and determine an optimal method for reducing cardiac dose, using literature from ScienceDirect, Medline and CINAHL. IMRT and breathing-adapted radiotherapy both reduce cardiac exposure but IMRT also increases the irradiated volume at low dose. Several issues were reported with regards to the clinical implementation of these techniques. It is suggested that inspiration breath-hold radiotherapy, is the preferred solution to minimising cardiac exposure but more research is warranted to confirm this. Long-term follow-up is required to determine dose–response relationships. Research needs to focus on breast cancer treatment as a whole in order to effectively reduce cardiac mortality.

Esophageal perforation during or after conformal radiotherapy for esophageal carcinoma

International Nuclear Information System (INIS)

Chen Haiyan; Ma Xiumei; Ye Ming; Hou Yanli; Xie Huaying; Bai Yongrui

2014-01-01

The aim of this study was to analyze the risk factors and prognosis for patients with esophageal perforation occurring during or after radiotherapy for esophageal carcinoma. We retrospectively analyzed 322 patients with esophageal carcinoma. These patients received radiotherapy for unresectable esophageal tumors, residual tumors after operation, or local recurrence. Of these, 12 had radiotherapy to the esophagus before being admitted, 68 patients had concurrent chemoradiotherapy (CRT), and 18 patients had esophageal perforation after RT (5.8%). Covered self-expandable metallic stents were placed in 11 patients. Two patients continued RT after stenting and control of infection; one of these suffered a new perforation, and the other had a massive hemorrhage. The median overall survival was 2 months (0-3 months) compared with 17 months in the non-perforation group. In univariate analysis, the Karnofsky performance status (KPS) being ≤ 70, age younger than 60, T4 stage, a second course of radiotherapy to the esophagus, extracapsular lymph nodes (LN) involving the esophagus, a total dose > 100 Gy (biologically effective dose -10 ), and CRT were risk factors for perforation. In multivariate analysis, age younger than 60, extracapsular LN involving the esophagus, T4 stage, and a second course of radiotherapy to the esophagus were risk factors. In conclusion, patients with T4 stage, extracapsular LN involving the esophagus, and those receiving a second course of RT should be given particular care to avoid perforation. The prognosis after perforation was poor. (author)

Multicentre dosimetric comparison of photon-junctioning techniques in head and neck radiotherapy

International Nuclear Information System (INIS)

Kron, T.

2003-01-01

Because many head and neck radiotherapy treatment techniques rely on a junction between X-ray fields, it was the aim of the present study to investigate the use of different junctioning techniques and the affect on the dose across the junction. Techniques in use at nine radiotherapy centres in Australia were investigated using thermoluminescence dosimetry (TLD). The techniques could broadly be divided into two groups: (i) use of the light field to match the fields after moving the patient; and (ii) use of asymmetric collimation to create a single isocentre located in the junction. The mean dose at the junction and its reproducibility was studied in five consecutive treatments in each centre using 25 TLD chips placed throughout the junction in an anthropomorphic phantom. There was a tendency for the mono-isocentric technique to deliver a lower, more accurate mean dose at the junction (Group I: 1.22 Gy (n = 8) vs Group II: 0.96 Gy (n = 5) for 1 Gy planned, some centres contributed to both technique) with greater reproducibility (Group I: 9.6%, Group II: 5.1 % of the mean dose). We conclude that a mono-isocentric treatment technique has the potential to deliver a more accurate and reproducible dose distribution at the field junction of photon beams in head and neck treatment. Copyright (2003) Blackwell Science Pty Ltd

SU-E-T-346: Effect of Jaw Position On Dose to Critical Structures in 3-D Conformal Radiotherapy Treatment of Pancreatic Cancer

Energy Technology Data Exchange (ETDEWEB)

Paudel, N; Han, E; Liang, X; Morrill, S; Zhang, X; Hardee, M; Penagaricano, J; Ratanatharathorn, V [Vaneerat, University of Arkansas for Medical Sciences, Little Rock, AR (United States)

2015-06-15

Purpose: Three-dimensional conformal therapy remains a valid and widely used modality for pancreatic radiotherapy treatment. It usually meets dose constraints on critical structures. However, careful positioning of collimation jaws can reduce dose to the critical structures. Here we investigate the dosimetric effect of jaw position in MLC-based 3-D conformal treatment planning on critical structures. Methods: We retrospectively selected seven pancreatic cancer patients treated with 3-D conformal radiotherapy. We started with treatment plans (Varian Truebeam LINAC, Eclipse TPS, AAA, 18MV) having both x and y jaws aligned with the farthest extent of the block outline (8mm around PTV). Then we subsequently moved either both x-jaws or all x and y jaws outwards upto 3 cm in 1 cm increments and investigated their effect on average and maximum dose to neighboring critical structures keeping the same coverage to treatment volume. Results: Lateral displacement of both x-jaws by 1cm each increased kidney and spleen mean dose by as much as 1.7% and 1.3% respectively and superior inferior displacement increased liver, right kidney, stomach and spleen dose by as much as 2.1%, 2%, 5.2% and 1.6% respectively. Displacement of all x and y-jaws away by 1cm increased the mean dose to liver, right kidney, left kidney, bowels, cord, stomach and spleen by as much as 4.9%, 5.9%, 2.1%, 2.8%, 7.4%, 10.4% and 4.2% respectively. Percentage increase in mean dose due to 2 and 3cm jaw displacement increased almost linearly with the displaced distance. Changes in maximum dose were much smaller (mostly negligible) than the changes in mean dose. Conclusion: Collimation jaw position affects dose mostly to critical structures adjacent to it. Though treatment plans with MLCs conforming the block margin usually meet dose constraints to critical structures, keeping jaws all the way in, to the edge of the block reduces dose to the critical structures during radiation treatment.

Technique for axillary radiotherapy using computer-assisted planning for high-risk skin cancerΤ

International Nuclear Information System (INIS)

Fogarty, G.B.; Martin, J.M.; Fay, M.; Ainslie J; Cassumbhoy, R.

2007-01-01

High-risk skin cancer arising on the upper limb or trunk can cause axillary nodal metastases. Previous studies have shown that axillary radiotherapy improves regional control. There is little published work on technique. Technique standardization is important in quality assurance and comparison of results especially for trials. Our technique, planned with CT assistance, is presented. To assess efficacy, an audit of patients treated in our institution over a 15-month period was conducted. Of 24 patients treated, 13 were treated with radical intent, 11 with this technique. With a follow up of over 2 years, the technique had more than a 90% (10/11) regional control in this radical group. Both of the radical patients who were not treated according to the technique had regional failure. One case of late toxicity was found, of asymptomatic lymphoedema in a radically treated patient. This technique for axillary radiotherapy for regional control of skin cancer is acceptable in terms of disease control and toxicity as validated by audit at 2 years

[Positioning errors of CT common rail technique in intensity-modulated radiotherapy for nasopharyngeal carcinoma].

Science.gov (United States)

Tian, Fei; Xu, Zihai; Mo, Li; Zhu, Chaohua; Chen, Chaomin

2012-11-01

To evaluate the value of CT common rail technique for application in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC). Twenty-seven NPC patients underwent Somatom CT scans using the Siemens CTVision system prior to the commencement of the radiotherapy sessions. The acquired CT images were registered with the planning CT images using the matching function of the system to obtain the linear set-up errors of 3 directions, namely X (left to right), Y (superior to inferior), and Z (anterior to posterior). The errors were then corrected online on the moving couch. The 27 NPC patients underwent a total of 110 CT scans and the displacement deviations of the X, Y and Z directions were -0.16∓1.68 mm, 0.25∓1.66 mm, and 0.33∓1.09 mm, respectively. CT common rail technique can accurately and rapidly measure the space error between the posture and the target area to improve the set-up precision of intensity-modulated radiotherapy for NPC.

Dosimetric Comparison of Three-Dimensional Conformal Proton Radiotherapy, Intensity-Modulated Proton Therapy, and Intensity-Modulated Radiotherapy for Treatment of Pediatric Craniopharyngiomas

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Boehling, Nicholas S. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bluett, Jaques B. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Palmer, Matthew T. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Song, Xiaofei; Amos, Richard A.; Sahoo, Narayan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Meyer, Jeffrey J.; Mahajan, Anita; Woo, Shiao Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2012-02-01

Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV) coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk

Radiotherapy Treatment Planning for Testicular Seminoma

International Nuclear Information System (INIS)

Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

2012-01-01

Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 × 1−2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior–posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior–posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

Radiotherapy Treatment Planning for Testicular Seminoma

Energy Technology Data Exchange (ETDEWEB)

Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

2012-07-15

Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

A custom made phantom for dosimetric audit and quality assurance of three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Radaideh, K.M.; Matalqah, L.M.; Matalqah, L.M.; Tajuddin, A.A.; Luen, F.W.L.; Bauk, S.; Abdel Munem, E.M.E.

2012-01-01

The ultimate check of the actual dose delivered to a patient in radiotherapy can be achieved by using dosimetric measurements. The aims of this study were to develop and evaluate a custom handmade head and neck phantom for evaluation of Three-Dimensional Conformal Radiation Therapy (3D-CRT) dose planning and delivery. A phantom of head and neck region of a medium built male patient with nasopharyngeal cancer was constructed from Perspex material. Primary and secondary Planning Target Volume (PTV) and twelve Organs at Risk (OAR) were delineated using Treatment Planning System (TPS) guided by computed tomography printout transverse images. One hundred and seven (107) holes distributed among the organs were loaded with Rod-shaped Thermoluminescent dosimeters (LiF:Mg, Ti TLDs) after common and individual calibration. Head and neck phantom was imaged, planned and irradiated conformally (3D-CRT) by linear accelerator (LINAC Siemens Artiste). The planned predicted doses by TPS at PTV and OAR regions were obtained and compared with the TLD measured doses using the phantom. Repeated TLD measurements were reproducible with a percent standard deviation of < 3.5 %. Moreover, the average of dose discrepancies between TLDs reading and TPS predicted doses were found to be < 5.3 %. The phantom's preliminary results have proved to be a valuable tool for 3D-CRT treatment dose verification. (author)

Tolerance and efficacy of conformal radiotherapy for hepatocellular carcinoma in cirrhotic patients. Results of the French RTF1 phase 2 trial; Tolerance et efficacite de la radiotherapie de conformation en cas de carcinome hepatocellulaire chez le patient cirrhotique. Resultats de l'essai de phase II RTF1

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Mornex, F.; Girard, N.; Wautot, V.; Khodri, M. [Centre Hospitalier Lyon-Sud, Dept. de Radiotherapie-Oncologie, 69 - Pierre-Benite (France); Merle, P.; Kubas, A.; Trepo, C. [Hopital de l' Hotel-Dieu, Service d' hepatogastroenterologie, 69 - Lyon (France); Beziat, C. [Hopital de l' Hotel-Dieu, Dept. de Radiologie, 69 - Lyon (France)

2005-11-15

Purpose. - While some patients presenting with hepatocellular carcinoma (HCC) benefit from curative therapies (transplantation, surgery, percutaneous ablation), others are only candidates for palliative options such as chemo-embolization or symptomatic care. Although conventional external-beam radiotherapy of the liver is regarded as little efficient and potentially toxic in cirrhotic patients, 3-dimensional conformal radiotherapy (CRT), by decreasing the amount of normal liver included in the radiation portal, allows dose escalation to occur without increasing the risk of radiation-induced hepatitis. This trial was designed to assess the efficacy and tolerance of CRT for small-size HCC in cirrhotic patients. Patients and methods. - Prospective phase II trial including stage A/B cirrhotic patients with small-size HCC not suitable for curative treatments; CRT consisted in a standard fractionation radiation, with a total dose of 66 Gy. Results. - Twenty-seven patients were included, 15 of whom had previously been treated for HCC; mean age was 68. Among the 23 assessable patients, 18 (78%) presented with complete response, 3 (13%) with partial response, and 2 with no response. Acute complications occurred in 24 patients, and were mainly acceptable (grade 1/2: 22 patients, grade 3/4: 11 patients, 4 (15%) of whom had clinical and/or hematological toxicities). Only 2 (9%) grade 3/4 clinical and/or hematological late toxicities are reported. Conclusion. - CRT is a non-invasive curative technique highly suitable for small-size HCC in cirrhotic patients; further investigations are needed to compare it to the other available treatments, and to integrate it into the curative therapeutic algorithm of HCC. (author)

A nonaxial boost may reduce late complications of radiotherapy for prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Ben-Josef, E; Mesina, C F; Choi, J; Forman, J D

1995-07-01

Purpose: The nonaxial external beam (NAEBT) prostate boost technique was designed to reduce late complications of radiotherapy for prostate cancer. It has been previously shown that with this beam arrangement, the volumes of bladder and rectum receiving high doses could be substantially reduced. This study was undertaken to find if these advantages in dose distribution would translate into clinically significant benefits. Materials and Methods: Follow-up was obtained on 106 prostate cancer patients who had been treated with 3D conformal radiotherapy. Late complications were scored using the RTOG scale. A standard four-field axial (STD) technique had been used to deliver 45 Gy to the prostate, seminal vesicles and periprostatic lymph-nodes. A subsequent 24 Gy boost had been delivered using a STD technique (58 patients) or a NAEBT technique (48 patients). In the latter, the opposing anterior and posterior pair of beams had been substituted for a right and left anterior infero-superior pair. Actuarial probabilities of developing late complications were calculated by the life-table method. The Mantel-Haenszel test was used to compare these probabilities between the two groups. Results: The groups were comparable in regard to age, race, pretreatment serum PSA, stage distribution and dose to prostate. With a median follow-up of 21 months, 18 patients have developed grade 1-2 gastrointestinal or genitourinary complications (14 in the STD group, 4 in the NAEBT group). There were no grade 3-4 complications. The actuarial 3-year complication probability was 58% and 11% in the STD and NAEBT groups, respectively. However, this difference was not statistically significant. Gastrointestinal and genitourinary complications were reduced from 12.1% to 6.2% and from 15.5% to 4.2%, respectively. Conclusion: The use of a nonaxial boost technique has resulted in fewer complications in patients treated with 3D conformal radiotherapy for localized prostate cancer. The greater reduction

A treatment planning comparison of two different 3D conformal techniques for irradiation of head and neck cancer patients

International Nuclear Information System (INIS)

Krstevska, Valentina; Lukarski, Dusko; Petkovska, Sonja

2010-01-01

The purpose of this treatment planning study was to compare two different three dimensional conformal irradiation techniques for head and neck cancer patients. For 33 patients with head and neck carcinoma, irradiated according to the classical technique, we computed and evaluated a second irradiation technique in order to optimize the treatment planning protocol. The classical technique, termed 'electron-photon fields', employed two lateral semi-fields (23 fractions) for irradiation of the upper part of the planning target volume that should receive 50 Gy (PTV50) and an anterior and posterior field for the lower part. After the 23rd fraction the lateral fields were reduced from the dorsal side (2 fractions), in order to exclude the spinal cord from them. At the same time the dose to the shielded part of the target volume was delivered with matched electron fields. Finally, after the 25th fraction, the high risk volume was irradiated to the desired dose with plan where the spinal cord was completely shielded. In the new technique, termed 'oblique photon fields', 4 oblique isocentric photon fields were used (25 fractions): two anterior fields that covered the entire target volume that should receive 50 Gy and two posterior fields that covered only half of the target volume in order to shield the spinal cord. Thus, the necessity for using electron fields is eliminated. We kept the plan for irradiation of the high risk planning target volume the same as in the classical technique. The prescribed dose per fraction in all plans was 2 Gy. In both techniques the plans were optimized to the same maximal point dose and the same dose to the spinal cord. The oblique fields plan showed better coverage and homogeneity of the PTV50, except for the patients with positive resection margins receiving postoperative radiotherapy (receiving 66 Gy), where the coverage did not differ significantly. The conformity in both techniques did not differ significantly. The mean dose to the

Skin-sparing Helical Tomotherapy vs 3D-conformal Radiotherapy for Adjuvant Breast Radiotherapy: In Vivo Skin Dosimetry Study

International Nuclear Information System (INIS)

Capelle, Lisa; Warkentin, Heather; MacKenzie, Marc; Joseph, Kurian; Gabos, Zsolt; Pervez, Nadeem; Tankel, Keith; Chafe, Susan; Amanie, John; Ghosh, Sunita; Parliament, Matthew; Abdulkarim, Bassam

2012-01-01

Purpose: We investigated whether treatment-planning system (TPS)-calculated dose accurately reflects skin dose received for patients receiving adjuvant breast radiotherapy (RT) with standard three-dimensional conformal RT (3D-CRT) or skin-sparing helical tomotherapy (HT). Methods and Materials: Fifty patients enrolled in a randomized controlled trial investigating acute skin toxicity from adjuvant breast RT with 3D-CRT compared to skin-sparing HT, where a 5-mm strip of ipsilateral breast skin was spared. Thermoluminescent dosimetry or optically stimulated luminescence measurements were made in multiple locations and were compared to TPS-calculated doses. Skin dosimetric parameters and acute skin toxicity were recorded in these patients. Results: With HT there was a significant correlation between calculated and measured dose in the medial and lateral ipsilateral breast (r = 0.67, P V50 (1.4% vs 5.9%, respectively; P=.001) but higher skin V40 and skin V30 (71.7% vs 64.0%, P=.02; and 99.0% vs 93.8%, P=.001, respectively) than 3D-CRT plans. Conclusion: The 3D-CRT TPS more accurately reflected skin dose than the HT TPS, which tended to overestimate dose received by 14% in patients receiving adjuvant breast RT.

Questionnaire based quality assurance for the RT01 trial of dose escalation in conformal radiotherapy for prostate cancer (ISRCTN 47772397)

International Nuclear Information System (INIS)

Mayles, W.; Moore, A.Rollo; Aird, Edwin G.A.; Bidmead, A. Margaret; Dearnaley, David P.; Griffiths, Sue E.; Stephens, Richard J.; Warrington, A.P. Jim

2004-01-01

Background and purpose: In order to ensure the validity of the outcome of the Medical Research Council's 'RT01 trial' of dose escalation in conformal radiotherapy for prostate cancer it was considered important that the quality of treatment delivery should meet an adequate standard across all contributing centres. A questionnaire was therefore devised to ensure that all aspects of the planning and delivery process were adequately covered. Patients and methods: The questionnaire considered each step in the planning and delivery process and drew the attention of the participants to the specific requirements of the trial. Before entering patients into the trial each participating centre had to complete the questionnaire and an outlining exercise (reported elsewhere). Results: It was not practicable to define a detailed universally acceptable protocol for the whole process of delivery of conformal radiotherapy, not least because of the different equipment available for planning and treatment in different centres. The questionnaire identified some areas of difference in practice between centres where there may be a need for the development of a consensus as to best practice, particularly in the area of patient set-up. Occasionally it was necessary to follow up responses to questions that had been misunderstood or inadequately answered, but in most cases these issues proved to be easily resolved. Conclusions: The questionnaire proved to be a useful self-assessment tool as well as enabling the quality assurance group to ensure that the standards of the trial were being met. Subsequent follow-up visits confirmed the usefulness and validity of this self assessment process

Current opinions on radiotherapy of pediatric central nervous system tumors

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Chojnacka, M.; Skowronska-Gardas, A.

2006-01-01

Primary central nervous system (CNS) neoplasms are the most frequent solid tumors in childhood accounting for 20% of all pediatric malignancies. Despite developments in neurosurgery, radiotherapy and chemotherapy, a significant proportion of these patients suffer progressive disease. A good treatment management strategy should consider not only survival but also the quality of life of the child. Irradiation is ann essential part of the management of the majority of CNS tumors. During then last decade, there significant advances in the technology of planning and delivery of radiation treatment. These new radiotherapy techniques such as conformal, intensity modulated photon beam and stereotactic methods allow a high homogenous dose to the tumor region with minimal doses to normal tissue. This is particularly important in children with localized low-grade tumors, whose prognosis of long-term survival is often excellent and should be accompanied by smallest risk of treatment toxicity. For small tumors fractionated radiotherapy stereotactic radiotherapy using multiple fixed non-coplanar beams is an appropriate treatment. Modification of craniospinal technique, lowering of the total craniospinal dose with adjuvant chemotherapy, new radiotherapy modalities to treat the posterior fossa may be employed to possibly decrease the late rectifies of radiation therapy. For malignant glioma and brain stem tumors we need new approaches, as chemo sensitization, angiogenesis inhibitors and gene therapies. These new methods in therapy of pediatric brain tumors and our experience in treatment of children with medulloblastoma, low-grade astrocytoma, craniopharyngioma and brain stem tumors are presented. We summarize therapeutic aspects of most childhood brain tumors. (author)

Definitive radiotherapy for locally advanced squamous cell carcinoma of the vulva and technical issues: a case report

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Kumar, Gokula; Norhafizah, I; Shazril, I; Nursyatina, AR; Abdul Aziz, MZ; Zin, Hafiz M; Zakir, MK; Norjayadi; Norliza, AS; Khairun, N; Ismail, A

2017-01-01

This case report describes a complex radical 3D-Conformal Radiotherapy treatment planning, dosimetric issues and outcome of definitive treatment of un-resectable carcinoma of the vulvar in a 42-year old lady. The patient presented with large fungating mass of the vulva which was biopsy confirmed as Keratinizing Squamous Cell Carcinoma. Further staging investigation revealed locally advanced disease (T4), with bilateral inguinal lymph nodes involvement. There is no systemic metastasis or intra-pelvic nodes. The patient was seen by Gynae-Oncology team and the disease was deemed un-resectable without significant morbidity. She was treated to a total dose of 64.8Gy in 36 fractions over 7 weeks with concurrent weekly Cisplatinum in 2 phases. 3D-Conformal radiotherapy technique using the modified segmental boost technique (MSBT, large PA and small AP photon fields with inguinal electron matching) was used. TLD chips were used for in-vivo dose verification in phase 1 and 2 of the treatment. At completion of planned radiotherapy, patient had a complete clinical response, grade 2-3 skin toxicity, grade 2 rectal toxicity, and grade 2 dysuria Vulval Squamous Cell Carcinomas are very radiosensitive tumours and the skills of the treating Radiation Oncologist, Dosimetrists, Physicist, Radiation Therapist and also nurses is of foremost importance is ensuring good clinical outcomes. (paper)

Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

International Nuclear Information System (INIS)

Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M.

1997-01-01

Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a '3-field' arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors)

High-dose (70-78 GY) conformal radiotherapy for prostate cancer; the relation between observed late bladder and rectum complications and parameters derived from the dose volume histograms

International Nuclear Information System (INIS)

Lebesque, J.V.; Bruce, A.; Boersma, L.J.; Velde, A. te

1996-01-01

Purpose: To determine the incidence of late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer, and to investigate the relation between these observed incidences and parameters derived from the Dose Volume Histograms (DVHs) of rectum and bladder wall. Patients and Methods: Hundred and thirty patients with T 2-4 G 1-3 N 0 M 0 prostate cancer were treated with conformal radiotherapy with the simultaneous boost technique in a dose-escalating protocol; 78 patients received a total dose of 70 Gy, 11 patients 74 - 76 Gy and 41 patients 78 Gy, each with a dose of 2 Gy per fraction. DVHs of the rectal wall were used to calculate NTCPs according to the model of Kutcher et al. with the estimated parameter values (n = 0.12, m = 0.15, TD 50 = 80 Gy) according to Burman et al. The median follow-up was 17 months (range 6 - 72 months). The crude and actuarial incidence of late (> 6 months) GI and GU complications were determined using the RTOG/EORTC morbidity scoring system (Grade I to IV). Results: Neither for late GI nor for GU complaints, a grade IV complication was observed. GU complaints occurred in 90 patients (69%): 54 patients (42%) only experienced grade I toxicity, 26 patients (20%) had grade II toxicity, and 10 patients (8%) had grade III complications, of which 8 patients (6%) developed a urethral (7 pts) or ureteric stenosis (1 pt). The actuarial incidence of grade III GU complications was 10% at 2 years. Since bladder wall DVHs are unreliable and most grade III complications were not related to the bladder, the grade II and/or III complications were analyzed in terms of the total prescribed dose only, but no correlation could be demonstrated. GI complications occurred in 71 patients (55%): 59 patients (45%) developed a grade I complication, 11 a grade II complication and only 1 patient required laser treatment twice and blood transfusion because of rectal bleeding (grade III). The actuarial incidence of GI

The superiority of hybrid-volumetric arc therapy (VMAT) technique over double arcs VMAT and 3D-conformal technique in the treatment of locally advanced non-small cell lung cancer – A planning study

International Nuclear Information System (INIS)

Chan, Oscar S.H.; Lee, Michael C.H.; Hung, Albert W.M.; Chang, Amy T.Y.; Yeung, Rebecca M.W.; Lee, Anne W.M.

2011-01-01

Purpose: To compare the dosimetric performance of three different treatment techniques – conformal radiotherapy (CRT), double arcs volumetric modulated arc therapy (RapidArc, RA) and Hybrid-RapidArc (H-RA) for locally-advanced non-small cell lung cancer (NSCLC). Material and methods: CRT, RA and H-RA plans were optimized for 24 stage III NSCLC patients. The target prescription dose was 60 Gy. CRT consisted of 5–7 coplanar fields, while RA comprised of two 204 o arcs. H-RA referred to two 204 o arcs plus 2 static fields, which accounted for approximately half of the total dose. The plans were optimized to fulfill the departmental plan acceptance criteria. Results: RA and H-RA yielded a 20% better conformity compared with CRT. Lung volume receiving >20 Gy (V20) and mean lung dose (MLD) were the lowest in H-RA (V20 1.7% and 2.1% lower, MLD 0.59 Gy and 0.41 Gy lower than CRT and RA respectively) without jeopardizing the low-dose lung volume (V5). H-RA plans gave the lowest mean maximum spinal cord dose (34.4 Gy, 3.9 Gy < CRT and 2.2 Gy < RA plans) and NTCP of lung. Higher average MU per fraction (addition 52.4 MU) was observed with a reduced treatment time compared with CRT plans. Conclusion: The H-RA technique was superior in dosimetric outcomes for treating locally-advanced NSCLC compared to CRT and RA.

Neuropsychological status in children and young adults with benign and low-grade brain tumors treated prospectively with focal stereotactic conformal radiotherapy

International Nuclear Information System (INIS)

Jalali, Rakesh; Goswami, Savita; Sarin, Rajiv; More, Niteen; Siddha, Manish; Kamble, Rashmi

2006-01-01

Purpose: To present prospective neuropsychological data at baseline and follow-up in children and young adults with benign and low-grade gliomas treated with focal stereotactic conformal radiotherapy (SCRT). Methods and Materials: A total of 22 patients (age 4-25 years) with residual/progressive benign and low-grade brain tumors considered suitable for SCRT underwent detailed and in-depth neuropsychological and cognitive testing at baseline before SCRT. The test battery included measurement of age-adjusted intelligence quotients (IQs) and cognitive parameters of visual, spatial, visuomotor, and attention concentrations. Anxiety was measured using the State-Trait Anxiety Inventory for Children and Hamilton Anxiety Rating Scale for patients >16 years old. Patients were treated with high-precision conformal radiotherapy under stereotactic guidance to a dose of 54 Gy in 30 fractions. All neuropsychological assessments were repeated at 6 and 24 months after SCRT completion and compared with the baseline values. Results: The baseline mean full-scale IQ before starting RT for patients 16 years, the corresponding value was 72 (range, 64-129). Of 20 evaluable patients, 14 (70%) had less than average IQs at baseline, even before starting radiotherapy. The verbal IQ, performance IQ, and full-scale IQ, as well as other cognitive scores, did not change significantly at the 6- and 24-month follow-up assessments for all patients. The memory quotient in older children and young adults was maintained at 6 and 24 months after SCRT, with a mean value of 93 and 100, respectively, compared with a mean baseline value of 81 before RT. The mean anxiety score in children measured by the C1 and C2 components of the State-Trait Anxiety Inventory for Children (STAIC) was 48 and 40, respectively, which improved significantly to mean values of 30 and 26, respectively, at the 24-month follow-up assessment (p = 0.005). The mean depression score in patients >16 years old was 23 at baseline and had

The study of treatment value of concurrent chemotherapy for patients with esophageal carcinoma received three-dimensional conformal radiotherapy or intensity modulated radiotherapy

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Wang Lan; Wang Jun; Han Chun; Zhang Jing; Li Xiaoning; Gao Chao

2011-01-01

Objective: To observe the acute side effects, local control rate and survival rate of concurrent chemoradiotherapy (CC) and radiotherapy alone (R) for patients with esophageal carcinoma. Methods: From June 2006 to February 2009, 209 patients with esophageal carcinoma were observed, 105 of them were treated with CC. Of all the patients, 117 received three-dimensional conformal radiotherapy, 92 received intensity modulated radiotherapy, the median prescription dose was 60 Gy. The regimen of LFP (5-FU, cisplatin and calcium folinate) was selected for this study, side effects, local control rate and survival rate were observed and subsets analysis were performed. Results: The overall follow-up rate was 99.0%,there were 99 and 44 patients whose follow-up time was more than 2 and 3 years, respectively;for the CC group, the data were 45 and 14, respectively; and for the R group, 54 and 30, respectively. The 1-, 2-, 3-year local control rates of CC group and R group were 88.1%, 69.2%, 66.2% and 81.0%, 64.0%, 54.9% (χ 2 =2.31, P=0.128), respectively. The 1-, 2-, 3-year overall survival rates of CC group and R group were 84.4%, 52.9%, 45.6% and 75.2%, 50.7%, 37.0%(χ 2 =1.57, P=0.210), respectively. Subset analysis indicated that for the patients of N 0 group and whose length of GTV >7 cm, the local control rate of CC was significantly higher than that of radiotherapy alone (χ 2 =5.11, 7.66; P=0.024, 0.006). For N 0 group, the survival rate of CC was higher than that of R alone. (χ 2 =5.07, P=0.024). The incidence of WBC, PLT and HGB reduction for the two groups were 81.9% and 49.0% (χ 2 =36.45, P=0.000), 14.3% and 1.9% (χ 2 =10.54, P=0.006), and 24.8% and 2.9% (χ 2 =22.95, P=0.000), respectively. The incidence of nausea, vomiting and constipation for the two groups were 63.8% and 7.7% (χ 2 =71.52, P=0.000), respectively. The incidence of ≥2 grade esophagitis of CC group and R group were 48.57% and 38.46% (χ 2 =2.17, P=0.141), respectively. The incidence of ≥2

Processing ultrafine-grained Aluminum alloy using Multi-ECAP-Conform technique

International Nuclear Information System (INIS)

Fakhretdinova, Elvira; Raab, Georgy; Valiev, Ruslan; Ryzhikov, Oleg

2014-01-01

The stress-strained state (SSS), contact and force parameters of a new SPD technique – Multi-ECAP-Conform – have been studied. The new technique ensures a high level of accumulated strain □=4...5 per one processing cycle. Physical and computer modeling by finite element method in Deform-3D software was applied to evaluate the parameters. It is shown that the results of physical and computer modeling correlate with each other. Equipment has been upgraded, and experimental samples of Al-Mg-Si system alloy have been processed

Contact radiotherapy. Report of technological assessment

International Nuclear Information System (INIS)

Ortholan, Cecile; Melin, Nicole; Lee-Robin, Sun Hae; David, Denis Jean; Pages, Frederique; Devaud, Christine; Noel, Georges; Biga, Julie; Moty-Monnereau, Celine; Canet, Philippe; Lascols, Sylvie; Lamas, Muriel; Ramdine, Jessica; Tuil, Louise

2008-10-01

This report aims at assessing safety, indications, the role in therapeutic strategy, and efficiency of contact radiotherapy. It also aims at answering questions like: is the contact radiotherapy technique validated? What are the indications for contact radiotherapy? What about the efficiency and safety of contact radiotherapy? After a presentation of preliminary notions on radiotherapy (radiation types, dose, and irradiation techniques), the report presents this specific technique of contact radiotherapy: definition, devices, use recommendations, issues of radiation protection, modalities of performance of a contact radiotherapy session, and concerned pathologies. Then, based on a literature survey, this report addresses the various concerned tumours (skin, rectum, brain, breast), indicates some general information about these tumours (epidemiological data, anatomy and classification, therapeutic options, radiotherapy), and proposes an assessment of the efficiency and safety of contact radiotherapy

Selection and determination of beam weights based on genetic algorithms for conformal radiotherapy treatment planning

International Nuclear Information System (INIS)

Xingen Wu; Zunliang Wang

2000-01-01

A genetic algorithm has been used to optimize the selection of beam weights for external beam three-dimensional conformal radiotherapy treatment planning. A fitness function is defined, which includes a difference function to achieve a least-square fit to doses at preselected points in a planning target volume, and a penalty item to constrain the maximum allowable doses delivered to critical organs. Adjustment between the dose uniformity within the target volume and the dose constraint to the critical structures can be achieved by varying the beam weight variables in the fitness function. A floating-point encoding schema and several operators, like uniform crossover, arithmetical crossover, geometrical crossover, Gaussian mutation and uniform mutation, have been used to evolve the population. Three different cases were used to verify the correctness of the algorithm and quality assessment based on dose-volume histograms and three-dimensional dose distributions were given. The results indicate that the genetic algorithm presented here has considerable potential. (author)

A Retrospective Comparison of Robotic Stereotactic Body Radiotherapy and Three-Dimensional Conformal Radiotherapy for the Reirradiation of Locally Recurrent Nasopharyngeal Carcinoma

International Nuclear Information System (INIS)

Ozyigit, Gokhan; Cengiz, Mustafa; Yazici, Gozde; Yildiz, Ferah; Gurkaynak, Murat; Zorlu, Faruk; Yildiz, Demet; Hosal, Sefik; Gullu, Ibrahim; Akyol, Fadil

2011-01-01

Purpose: We assessed therapeutic outcomes of reirradiation with robotic stereotactic radiotherapy (SBRT) for locally recurrent nasopharyngeal carcinoma (LRNPC) patients and compared those results with three-dimensional conformal radiotherapy (CRT) with or without brachytherapy (BRT). Methods and Materials: Treatment outcomes were evaluated retrospectively in 51 LRNPC patients receiving either robotic SBRT (24 patients) or CRT with or without BRT (27 patients) in our department. CRT was delivered with a 6-MV linear accelerator, and a median total reirradiation dose of 57 Gy in 2 Gy/day was given. Robotic SBRT was delivered with CyberKnife (Accuray, Sunnyvale, CA). Patients in the SBRT arm received 30 Gy over 5 consecutive days. We calculated actuarial local control and cancer-specific survival rates for the comparison of treatment outcomes in SBRT and CRT arms. The Common Terminology Criteria for Adverse Events v3.0 was used for toxicity evaluation. Results: The median follow-up was 24 months for all patients. Two-year actuarial local control rates were 82% and 80% for SBRT and CRT arms, respectively (p = 0.6). Two-year cancer-specific survival rates were 64% and 47% for the SBRT and CRT arms, respectively (p = 0.4). Serious late toxicities (Grade 3 and above) were observed in 21% of patients in the SBRT arm, whereas 48% of patients had serious toxicity in the CRT arm (p = 0.04). Fatal complications occurred in three patients (12.5%) of the SBRT arm, and four patients (14.8%) of the CRT arm (p = 0.8). T stage at recurrence was the only independent predictor for local control and survival. Conclusion: Our robotic SBRT protocol seems to be feasible and less toxic in terms of late effects compared with CRT arm for the reirradiation of LRNPC patients.

Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

Energy Technology Data Exchange (ETDEWEB)

Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M. [Hong Kong Polytechnic University, Hong Kong, (Hong Kong). Department of Radiography and Optometry

1997-04-01

Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a `3-field` arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors). 14 refs., 3 tabs., 6 figs.

Benchmarking Dosimetric Quality Assessment of Prostate Intensity-Modulated Radiotherapy

International Nuclear Information System (INIS)

Senthi, Sashendra; Gill, Suki S.; Haworth, Annette; Kron, Tomas; Cramb, Jim; Rolfo, Aldo; Thomas, Jessica; Duchesne, Gillian M.; Hamilton, Christopher H.; Joon, Daryl Lim; Bowden, Patrick; Foroudi, Farshad

2012-01-01

Purpose: To benchmark the dosimetric quality assessment of prostate intensity-modulated radiotherapy and determine whether the quality is influenced by disease or treatment factors. Patients and Methods: We retrospectively analyzed the data from 155 consecutive men treated radically for prostate cancer using intensity-modulated radiotherapy to 78 Gy between January 2007 and March 2009 across six radiotherapy treatment centers. The plan quality was determined by the measures of coverage, homogeneity, and conformity. Tumor coverage was measured using the planning target volume (PTV) receiving 95% and 100% of the prescribed dose (V 95% and V 100% , respectively) and the clinical target volume (CTV) receiving 95% and 100% of the prescribed dose. Homogeneity was measured using the sigma index of the PTV and CTV. Conformity was measured using the lesion coverage factor, healthy tissue conformity index, and the conformity number. Multivariate regression models were created to determine the relationship between these and T stage, risk status, androgen deprivation therapy use, treatment center, planning system, and treatment date. Results: The largest discriminatory measurements of coverage, homogeneity, and conformity were the PTV V 95% , PTV sigma index, and conformity number. The mean PTV V 95% was 92.5% (95% confidence interval, 91.3–93.7%). The mean PTV sigma index was 2.10 Gy (95% confidence interval, 1.90–2.20). The mean conformity number was 0.78 (95% confidence interval, 0.76–0.79). The treatment center independently influenced the coverage, homogeneity, and conformity (all p 95% only, with it being better at the start (p = .013). Risk status, T stage, and the use of androgen deprivation therapy did not influence any aspect of plan quality. Conclusion: Our study has benchmarked measures of coverage, homogeneity, and conformity for the treatment of prostate cancer using IMRT. The differences seen between centers and planning systems and the coverage

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

International Nuclear Information System (INIS)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G.

2002-01-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7±17.1 and 40.4±16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7±4.8 ccm for 3D-HOF and 10.7±12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

Energy Technology Data Exchange (ETDEWEB)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G. [National Research Inst. for Radiobiology and Radiohygiene, Budapest (Hungary)

2002-04-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7{+-}17.1 and 40.4{+-}16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7{+-}4.8 ccm for 3D-HOF and 10.7{+-}12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma.

FDG-PET/CT Imaging for Staging and Target Volume Delineation in Preoperative Conformal Radiotherapy of Rectal Cancer

International Nuclear Information System (INIS)

Bassi, Maria Chiara; Turri, Lucia; Sacchetti, Gianmauro; Loi, Gianfranco; Cannillo, Barbara; La Mattina, Pierdaniele; Brambilla, Marco; Inglese, Eugenio; Krengli, Marco

2008-01-01

Purpose: To investigate the potential impact of using 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on staging and target volume delineation for patients affected by rectal cancer and candidates for preoperative conformal radiotherapy. Methods and Materials: Twenty-five patients diagnosed with rectal cancer T3-4 N0-1 M0-1 and candidates for preoperative radiotherapy underwent PET/CT simulation after injection of 5.18 MBq/kg of FDG. Clinical stage was reassessed on the basis of FDG-PET/CT findings. The gross tumor volume (GTV) and the clinical target volume (CTV) were delineated first on CT and then on PET/CT images. The PET/CT-GTV and PET/CT-CTV were analyzed and compared with CT-GTV and CT-CTV, respectively. Results: In 4 of 25 cases (24%), PET/CT affected tumor staging or the treatment purpose. In 3 of 25 cases (12%) staged N0 M0, PET/CT showed FDG uptake in regional lymph nodes and in a case also in the liver. In a patient with a single liver metastasis PET/CT detected multiple lesions, changing the treatment intent from curative to palliative. The PET/CT-GTV and PET/CT-CTV were significantly greater than the CT-GTV (p = 0.00013) and CT-CTV (p = 0.00002), respectively. The mean difference between PET/CT-GTV and CT-GTV was 25.4% and between PET/CT-CTV and CT-CTV was 4.1%. Conclusions: Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively

Cervix carcinomas: place of intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Barillot, I.

2009-01-01

While indications of modulated intensity radiation therapy (I.M.R.T.) are perfectly defined in head and neck and prostate cancer patients, this technique remains under evaluation for gynecologic tumours. The implementation of conformal three dimensional radiotherapy in the late 1990 has been the first important step for optimisation of treatment of cervix carcinomas, as it permitted a better target coverage with a significant reduction of the bladder dose. However, this technique often leads to an irradiation of a larger volume of rectum in locally advanced stages and could only spare a limited amount of intestine. I.R.M.T. is one of the optimisation methods potentially efficient for a better sparing of digestive tract during irradiation of cervix carcinomas. The aim of this literature review is to provide the arguments supporting this hypothesis, and to define the place of this technique for dose escalation. (authors)

Treatment of nasal cavity and paranasal sinus cancer with modern radiotherapy techniques in the postoperative setting-the MSKCC experience

International Nuclear Information System (INIS)

Hoppe, Bradford S.; Stegman, Lauren D.; Zelefsky, Michael J.; Rosenzweig, Kenneth E.; Wolden, Suzanne L.; Patel, Snehal G.; Shah, Jatin P.; Kraus, Dennis H.; Lee, Nancy Y.

2007-01-01

Purpose: To perform a retrospective analysis of patients with paranasal sinus (PNS) cancer treated with postoperative radiotherapy (RT) at Memorial Sloan-Kettering Cancer Center. Methods and Materials: Between January 1987 and July 2005, 85 patients with PNS and nasal cavity cancer underwent postoperative RT. Most patients had squamous cell carcinoma (49%; n = 42), T4 tumors (52%; n = 36), and the maxillary sinus (53%; n = 45) as the primary disease site. The median radiation dose was 63 Gy. Of the 85 patients, 76 underwent CT simulation and 53 were treated with either three-dimensional conformal RT (27%; n = 23) or intensity-modulated RT (35%; n = 30). Acute and late toxicities were scored according to the Radiation Therapy Oncology Group radiation morbidity scoring criteria. Results: With a median follow-up for surviving patients of 60 months, the 5-year estimates of local progression-free, regional progression-free, distant metastasis-free, disease-free, and overall survival rates were 62%, 87%, 82%, 55%, and 67%, respectively. On multivariate analysis, squamous cell histology and cribriform plate involvement predicted for an increased likelihood of local recurrence, and squamous cell histologic features predicted for worse overall survival. None of the patients who underwent CT simulation and were treated with modern techniques developed a Grade 3-4 late complication of the eye. Conclusion: Complete surgical resection followed by adjuvant RT is an effective and safe approach in the treatment of PNS cancer. Emerging tools, such as three-dimensional conformal treatment and, in particular, intensity-modulated RT for PNS tumors, may minimize the occurrence of late complications associated with conventional RT techniques. Local recurrence remains a significant problem

The therapeutic effect of three-dimensional conformal radiation therapy combined with conventional radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Liang Feng; Lu Zhonghong; Yao Zhijun; Cao Yongzhen

2011-01-01

Objective: To observe the therapeutic effect of three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC). Methods: 78 patients with NPC was treated by radiation schedule in two phases. In the first phase, nasopharyngeal lesions and metastases of all patients were treated by three-dimensional conformal radiation therapy (3DCRT) with a fraction of 2-5 Gy daily, 5 day per weeks, total dose 30 Gy. The second phase T1N0 or parts of T2N0 patients were done by Conventional radiotherapy with total dose 55 Gy on two small lateral opposing fields + with total dose 50 Gy on neck on tangential field,adding a 3 cm block. Patients with lymph node metastasis were given 55 Gy on the dacio-neck field (After 40 Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded) + with total dose 55 Gy on lower neck on tangential field. The upper bound of designed therapeutic field was set to connect with lower bound of main therapeutic field. Results: Three months after treatment,the rate of CR, PR, SD, PD were 38.5%, 55.1%, 5.1%, 1.3%, Total effective rate (CR+PR) were 93.6%. The 1-year, 2-year, 3-year and 5-year local-regional control rates were 92.3%, 88.5%, 78.2%, 70.5%.The 1-year, 2-year , 3-year and 5-year overall survival rate were 96.2%, 89.7%, 83.3%, 71.8%. Appearing early radiation response is well tolerated and no obviously mouth difficulties and cranial nerve damage observed. Conclusion: Clinical result of early-course three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC) is good. (authors)

Radiotherapy physics

International Nuclear Information System (INIS)

Chen, G.T.Y.; Collier, J.M.; Lyman, J.T.; Pitluck, S.

1982-01-01

The Radiotherapy Physics Group works on the physical and biophysical aspects of charged particle radiotherapy. Our activities include the development of isosurvival beams (beams of uniform biological effect), computerized treatment planning development for charged particle radiotherapy, design of compensation to shape dose distributions, and development of dosimetry techniques to verify planned irradiations in both phantoms and patients

Animation and radiobiological analysis of 3D motion in conformal radiotherapy.

Science.gov (United States)

MacKay, R I; Graham, P A; Moore, C J; Logue, J P; Sharrock, P J

1999-07-01

To allow treatment plans to be evaluated against the range of expected organ motion and set up error anticipated during treatment. Planning tools have been developed to allow concurrent animation and radiobiological analysis of three dimensional (3D) target and organ motion in conformal radiotherapy. Surfaces fitted to structures outlined on CT studies are projected onto pre-treatment images or onto megavoltage images collected during the patient treatment. Visual simulation of tumour and normal tissue movement is then performed by the application of three dimensional affine transformations, to the selected surface. Concurrent registration of the surface motion with the 3D dose distribution allows calculation of the change in dose to the volume. Realistic patterns of motion can be applied to the structure to simulate inter-fraction motion and set-up error. The biologically effective dose for the structure is calculated for each fraction as the surface moves over the course of the treatment and is used to calculate the normal tissue complication probability (NTCP) or tumour control probability (TCP) for the moving structure. The tool has been used to evaluate conformal therapy plans against set up measurements recorded during patient treatments. NTCP and TCP were calculated for a patient whose set up had been corrected after systematic deviations from plan geometry were measured during treatment, the effect of not making the correction were also assessed. TCP for the moving tumour was reduced if inadequate margins were set for the treatment. Modelling suggests that smaller margins could have been set for the set up corrected during the course of the treatment. The NTCP for the rectum was also higher for the uncorrected set up due to a more rectal tissue falling in the high dose region. This approach provides a simple way for clinical users to utilise information incrementally collected throughout the whole of a patient's treatment. In particular it is possible to

Intensity-Modulated Radiotherapy for Sinonasal Cancer: Improved Outcome Compared to Conventional Radiotherapy

International Nuclear Information System (INIS)

Dirix, Piet; Vanstraelen, Bianca; Jorissen, Mark; Vander Poorten, Vincent; Nuyts, Sandra

2010-01-01

Purpose: To evaluate clinical outcome and toxicity of postoperative intensity-modulated radiotherapy (IMRT) for malignancies of the nasal cavity and paranasal sinuses. Methods and Materials: Between 2003 and 2008, 40 patients with cancer of the paranasal sinuses (n = 34) or nasal cavity (n = 6) received postoperative IMRT to a dose of 60 Gy (n = 21) or 66 Gy (n = 19). Treatment outcome and toxicity were retrospectively compared with that of a previous patient group (n = 41) who were also postoperatively treated to the same doses but with three-dimensional conformal radiotherapy without intensity modulation, from 1992 to 2002. Results: Median follow-up was 30 months (range, 4-74 months). Two-year local control, overall survival, and disease-free survival were 76%, 89%, and 72%, respectively. Compared to the three-dimensional conformal radiotherapy treatment, IMRT resulted in significantly improved disease-free survival (60% vs. 72%; p = 0.02). No grade 3 or 4 toxicity was reported in the IMRT group, either acute or chronic. The use of IMRT significantly reduced the incidence of acute as well as late side effects, especially regarding skin toxicity, mucositis, xerostomia, and dry-eye syndrome. Conclusions: Postoperative IMRT for sinonasal cancer significantly improves disease-free survival and reduces acute as well as late toxicity. Consequently, IMRT should be considered the standard treatment modality for malignancies of the nasal cavity and paranasal sinuses.

BENEFITS OF INTENSITY-MODULATED RADIOTHERAPY (IMRT IN PATIENTS WITH HEAD AND NECK MALIGNANCIES- A SINGLE INSTITUTION EXPERIENCE

Directory of Open Access Journals (Sweden)

Sherry Seasor Abraham

2017-09-01

Full Text Available BACKGROUND Radiotherapy and surgery are the principal curative modalities in treatment of head and neck cancer. Conventional twodimensional and three-dimensional conformal radiotherapy result in significant side effects and altered quality of life. IntensityModulated Radiotherapy (IMRT can spare the normal tissues, while delivering a curative dose to the tumour-bearing tissues. This study reveals the role of IMRT in head and neck cancer in view of normal tissue sparing with good tumour control. MATERIALS AND METHODS Radical radiotherapy was given using linear accelerator up to a dose of 66 to 70 gray in 30 to 33 fractions (intensity-modulated radiotherapy with simultaneous integrated boost over 6 to 7 weeks to 56 eligible patients. Concurrent cisplatin was given to patients with locally-advanced disease up to a dose of 40 mg/m2 weekly once along with radiation. The patients were monitored weekly once during the treatment for acute skin and mucosal toxicities using the RTOG scoring criteria. After the treatment, locoregional response was assessed and recorded at 6 weeks, 3 months and 6 months intervals. RESULTS Severe skin toxicity (grade III or more was seen in approximately 7% patients. Severe mucosal toxicity (grade III or more was seen in approximately 80% of patients. IMRT technique showed better skin sparing compared to 3D conformal radiotherapy. Severe mucosal toxicity was slightly higher in this study due to the simultaneous integrated boost technique used for dose intensification to the mucosa, which results in better primary tumour control. At the end of 6 months, 75% patients achieved locoregional control and residual/recurrent disease was seen in 25% of patients. IMRT offered good locoregional control with less skin toxicity and acceptable mucosal toxicity. The results were similar to the previous study reports using IMRT. CONCLUSION IMRT is a better treatment option in locally-advanced head and neck malignancies providing good

Nasopharyngeal Carcinoma Treated with Precision-Oriented Radiation Therapy Techniques Including Intensity-Modulated Radiotherapy: Preliminary Results

Directory of Open Access Journals (Sweden)

Wen-Shan Liu

2004-02-01

Full Text Available This paper reports preliminary results with intensity-modulated radiotherapy (IMRT in nasopharyngeal carcinoma (NPC. Between August 2000 and May 2001, we treated 19 patients with NPC using IMRT. Twelve patients had stage I-II disease and seven had stage III-IV disease. Six patients received 9.0-19.8 Gy three-dimensional conformal radiotherapy (3D-CRT before IMRT and 18 patients received a brachytherapy boost after IMRT. The mean follow-up time was 13.0 months. All patients with stage II-IV disease except one received two cycles of chemoradiotherapy with cisplatin and 5-fluorouracil (5-FU during radiotherapy, followed by two to four cycles of chemotherapy after radiotherapy. Tumor response was assessed using clinical examination and computerized tomography or magnetic resonance imaging. The mean doses administered to the gross tumor volume and clinical tumor volume were 70.9 Gy and 63.2 Gy, respectively. The mean doses administered to the right and left parotid glands were 38.1 Gy and 38.6 Gy, respectively. All 19 patients had a complete response of primary and lymph node disease. Grade III mucositis developed during chemoradiotherapy in 15 patients (79%. In addition, clinical grade I xerostomia was recorded in nine patients, grade II in nine, and grade III in one. This study demonstrated that 3D-CRT, IMRT, intracavitary brachytherapy, and chemotherapy are effective and safe methods to treat NPC. Although IMRT treatment spared parotid gland function, its efficacy may be significantly influenced by disease stage and location of the neck lymph nodes. More cases and a longer follow-up to assess survival and complications are planned.

Accelerated Deformable Registration of Repetitive MRI during Radiotherapy in Cervical Cancer

DEFF Research Database (Denmark)

Noe, Karsten Østergaard; Tanderup, Kari; Kiritsis, Christian

2006-01-01

Tumour regression and organ deformations during radiotherapy (RT) of cervical cancer represent major challenges regarding accurate conformation and calculation of dose when using image-guided adaptive radiotherapy. Deformable registration algorithms are able to handle organ deformations, which can...... be useful with advanced tools such as auto segmentation of organs and dynamic adaptation of radiotherapy. The aim of this study was to accelerate and validate deformable registration in MRI-based image-guided radiotherapy of cervical cancer.    ...

SU-E-T-809: Volumetric Modulated Arc Radiotherapy Vs. Intensity-Modulated Radiotherapy for Locally Advanced Laryngeal Carcinoma: A Dosimetric Study

Energy Technology Data Exchange (ETDEWEB)

Lu, J-Y; Huang, B-T; Zhang, W-Z; Yan, L-J [Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China)

2015-06-15

Purpose: To compare volumetric modulated arc radiotherapy (VMAT) technique with fixed-gantry intensity-modulated radiotherapy (IMRT) technique for locally advanced laryngeal carcinoma. Methods: CT datasets of eleven patients were included. Dual-arc VMAT and 7-field IMRT plans, which were created based on the Eclipse treatment planning system, were compared in terms of dose-volume parameters, conformity index (CI) and homogeneity index (HI) of planning target volume (PTV), as well as organ-at-risk (OAR) sparing, planning time, monitor units (MUs) and delivery time. Results: Compared with the IMRT plans, the VMAT plans provided lower D2% and better CI/HI for the high-risk PTV (PTV1), and provided better CI and comparable HI for the low-risk PTV (PTV2). Concerning the OAR sparing, the VMAT plans demonstrated significantly lower Dmax of the spinal cord (planning OAR volume, PRV) and brainstem (PRV), as well as lower Dmean and V30Gy of the right parotid. No significant differences were observed between the two plans concerning the doses delivered to the thyroid, carotid, oral cavity and left parotid. Moreover, the VMAT planning (147 ± 18 min) consumed 213% more time than the IMRT planning (48 ± 10 min). The MUs of the VMAT plans (556 ± 52) were 64% less than those of the IMRT plans (1684 ± 409), and the average delivery time (2.1 ± 0.1 min) was 66% less than that of the IMRT plans (6.3 ± 0.7 min). Conclusion: Compared with the IMRT technique, the VMAT technique can achieve superior target dose distribution and better sparing of the spinal cord, brainstem and right parotid, with less MUs and less delivery time. It is recommended for the radiotherapy of locally advanced laryngeal carcinoma.

Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT; Solucion de clase para disminuir dosis en recto en tratamientos de prostata con radioterapia 3D-CRT

Energy Technology Data Exchange (ETDEWEB)

Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

2011-07-01

This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

Simultaneous optimization of beam orientations and beam weights in conformal radiotherapy

International Nuclear Information System (INIS)

Rowbottom, Carl Graham; Khoo, Vincent S.; Webb, Steve

2001-01-01

A methodology for the concurrent optimization of beam orientations and beam weights in conformal radiotherapy treatment planning has been developed and tested on a cohort of five patients. The algorithm is based on a beam-weight optimization scheme with a downhill simplex optimization engine. The use of random voxels in the dose calculation provides much of the required speed up in the optimization process, and allows the simultaneous optimization of beam orientations and beam weights in a reasonable time. In the implementation of the beam-weight optimization algorithm just 10% of the original patient voxels are used for the dose calculation and cost function evaluation. A fast simulated annealing algorithm controls the optimization of the beam arrangement. The optimization algorithm was able to produce clinically acceptable plans for the five patients in the cohort study. The algorithm equalized the dose to the optic nerves compared to the standard plans and reduced the mean dose to the brain stem by an average of 4.4% (±1.9, 1 SD), p value=0.007. The dose distribution to the PTV was not compromised by developing beam arrangements via the optimization algorithm. In conclusion, the simultaneous optimization of beam orientations and beam weights has been developed to be routinely used in a realistic time. The results of optimization in a small cohort study show that the optimization can reliably produce clinically acceptable dose distributions and may be able to improve dose distributions compared to those from a human planner

Left-sided breast cancer irradiation using rotational and fixed-field radiotherapy

International Nuclear Information System (INIS)

Qi, X. Sharon; Liu, Tian X.; Liu, Arthur K.; Newman, Francis; Rabinovitch, Rachel; Kavanagh, Brian; Hu, Y. Angie

2014-01-01

The 3-dimensional conformal radiotherapy (3DCRT) technique is the standard for breast cancer radiotherapy. During treatment planning, not only the coverage of the planning target volume (PTV) but also the minimization of the dose to critical structures, such as the lung, heart, and contralateral breast tissue, need to be considered. Because of the complexity and variations of patient anatomy, more advanced radiotherapy techniques are sometimes desired to better meet the planning goals. In this study, we evaluated external-beam radiation treatment techniques for left breast cancer using various delivery platforms: fixed-field including TomoDirect (TD), static intensity-modulated radiotherapy (sIMRT), and rotational radiotherapy including Elekta volumetric-modulated arc therapy (VMAT) and tomotherapy helical (TH). A total of 10 patients with left-sided breast cancer who did or did not have positive lymph nodes and were previously treated with 3DCRT/sIMRT to the entire breast were selected, their treatment was planned with Monaco VMAT, TD, and TH. Dosimetric parameters including PTV coverage, organ-at-risk (OAR) sparing, dose-volume histograms, and target minimum/maximum/mean doses were evaluated. It is found that for plans providing comparable PTV coverage, the Elekta VMAT plans were generally more inhomogeneous than the TH and TD plans. For the cases with regional node involvement, the average mean doses administered to the heart were 9.2 (± 5.2) and 8.8 (± 3.0) Gy in the VMAT and TH plans compared with 11.9 (± 6.4) and 11.8 (± 9.2) Gy for the 3DCRT and TD plans, respectively, with slightly higher doses given to the contralateral lung or breast or both. On average, the total monitor units for VMAT plans are 11.6% of those TH plans. Our studies have shown that VMAT and TH plans offer certain dosimetric advantages over fixed-field IMRT plans for advanced breast cancer requiring regional nodal treatment. However, for early-stage breast cancer fixed

Clinical research of teeth damage from radiotherapy

International Nuclear Information System (INIS)

Li Erzhou; Yan Maosheng; Chen Wei; Li Qing

2003-01-01

Objective: To analyze various factors inducing teeth damage from radiotherapy and the preventive and treatment methods. Methods: One hundred cases of patients treated by radiotherapy were divided into two groups. In group one there were 60 cases whose teeth were irradiated during treatment; in group two there were 40 cases whose teeth were not irradiated during treatment. Results: The caries incidence was 60% for group one and 15% for group two (P<0.01). By auto-control in 15 patients, the caries incidence on the sick side was obviously higher than that of the healthy side. Hundred percent caries incidence was found in 6 cases who received a dosage of 70 Gy. Conclusion: The authors believe that radiation damage to the teeth is associated with the following factors: 1. The dosage and location of irradiation are closely related to caries incidence; 2. The active dentinoblasts are very sensitive to radiation; 3. Damage to the salivary glands from radiotherapy can result in reduction of salvia and pH value, leading to a high growth rate of Streptococcus mutans. Following preventive measures could be considered in future cases: to apply a caries prevention coating or protective dental crown and TPS, to adjust the dose and time of irradiation, to select conformal radiotherapy technique. The key points for protecting the teeth and salivary gland from caries and damage are protection of the proliferation ability of pulp cells, anti-inflammation, promotion of microcirculation, and strengthening body resistance

Markerless gating for lung cancer radiotherapy based on machine learning techniques

International Nuclear Information System (INIS)

Lin Tong; Li Ruijiang; Tang Xiaoli; Jiang, Steve B; Dy, Jennifer G

2009-01-01

In lung cancer radiotherapy, radiation to a mobile target can be delivered by respiratory gating, for which we need to know whether the target is inside or outside a predefined gating window at any time point during the treatment. This can be achieved by tracking one or more fiducial markers implanted inside or near the target, either fluoroscopically or electromagnetically. However, the clinical implementation of marker tracking is limited for lung cancer radiotherapy mainly due to the risk of pneumothorax. Therefore, gating without implanted fiducial markers is a promising clinical direction. We have developed several template-matching methods for fluoroscopic marker-less gating. Recently, we have modeled the gating problem as a binary pattern classification problem, in which principal component analysis (PCA) and support vector machine (SVM) are combined to perform the classification task. Following the same framework, we investigated different combinations of dimensionality reduction techniques (PCA and four nonlinear manifold learning methods) and two machine learning classification methods (artificial neural networks-ANN and SVM). Performance was evaluated on ten fluoroscopic image sequences of nine lung cancer patients. We found that among all combinations of dimensionality reduction techniques and classification methods, PCA combined with either ANN or SVM achieved a better performance than the other nonlinear manifold learning methods. ANN when combined with PCA achieves a better performance than SVM in terms of classification accuracy and recall rate, although the target coverage is similar for the two classification methods. Furthermore, the running time for both ANN and SVM with PCA is within tolerance for real-time applications. Overall, ANN combined with PCA is a better candidate than other combinations we investigated in this work for real-time gated radiotherapy.

Five-year follow-up using a prostate stent as fiducial in image-guided radiotherapy of prostate cancer.

Science.gov (United States)

Carl, Jesper; Sander, Lotte

2015-06-01

To report results from the five-year follow-up on a previously reported study using image-guided radiotherapy (IGRT) of localized or locally advanced prostate cancer (PC) and a removable prostate stent as fiducial. Patients with local or locally advanced PC were treated using five-field 3D conformal radiotherapy (3DRT). The clinical target volumes (CTV) were treated to 78 Gy in 39 fractions using daily on-line image guidance (IG). Late genito-urinary (GU) and gastro-intestinal (GI) toxicities were scored using the radiotherapy oncology group (RTOG) score and the common toxicity score of adverse events (CTC) score. Urinary symptoms were also scored using the international prostate symptom score (IPSS). Median observation time was 5.4 year. Sixty-two of the 90 patients from the original study cohort were eligible for toxicity assessment. Overall survival, cancer-specific survival and biochemical freedom from failure were 85%, 96% and 80%, respectively at five years after radiotherapy. Late toxicity GU and GI RTOG scores≥2 were 5% and 0%. Comparing pre- and post-radiotherapy IPSS scores indicate that development in urinary symptoms after radiotherapy may be complex. Prostate image-guided radiotherapy using a prostate stent demonstrated survival data comparable with recently published data. GU and GI toxicities at five-year follow-up were low and comparable to the lowest toxicity rates reported. These findings support that the precision of the prostate stent technique is at least as good as other techniques. IPSS revealed a complex development in urinary symptoms after radiotherapy.

Benchmarking Dosimetric Quality Assessment of Prostate Intensity-Modulated Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Senthi, Sashendra, E-mail: sasha.senthi@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Gill, Suki S. [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Haworth, Annette; Kron, Tomas; Cramb, Jim [Department of Physical Sciences, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Rolfo, Aldo [Radiation Therapy Services, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Thomas, Jessica [Biostatistics and Clinical Trials, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Duchesne, Gillian M. [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Hamilton, Christopher H.; Joon, Daryl Lim [Radiation Oncology Department, Austin Repatriation Hospital, Heidelberg, VIC (Australia); Bowden, Patrick [Radiation Oncology Department, Tattersall' s Cancer Center, East Melbourne, VIC (Australia); Foroudi, Farshad [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia)

2012-02-01

Purpose: To benchmark the dosimetric quality assessment of prostate intensity-modulated radiotherapy and determine whether the quality is influenced by disease or treatment factors. Patients and Methods: We retrospectively analyzed the data from 155 consecutive men treated radically for prostate cancer using intensity-modulated radiotherapy to 78 Gy between January 2007 and March 2009 across six radiotherapy treatment centers. The plan quality was determined by the measures of coverage, homogeneity, and conformity. Tumor coverage was measured using the planning target volume (PTV) receiving 95% and 100% of the prescribed dose (V{sub 95%} and V{sub 100%}, respectively) and the clinical target volume (CTV) receiving 95% and 100% of the prescribed dose. Homogeneity was measured using the sigma index of the PTV and CTV. Conformity was measured using the lesion coverage factor, healthy tissue conformity index, and the conformity number. Multivariate regression models were created to determine the relationship between these and T stage, risk status, androgen deprivation therapy use, treatment center, planning system, and treatment date. Results: The largest discriminatory measurements of coverage, homogeneity, and conformity were the PTV V{sub 95%}, PTV sigma index, and conformity number. The mean PTV V{sub 95%} was 92.5% (95% confidence interval, 91.3-93.7%). The mean PTV sigma index was 2.10 Gy (95% confidence interval, 1.90-2.20). The mean conformity number was 0.78 (95% confidence interval, 0.76-0.79). The treatment center independently influenced the coverage, homogeneity, and conformity (all p < .0001). The planning system independently influenced homogeneity (p = .038) and conformity (p = .021). The treatment date independently influenced the PTV V{sub 95%} only, with it being better at the start (p = .013). Risk status, T stage, and the use of androgen deprivation therapy did not influence any aspect of plan quality. Conclusion: Our study has benchmarked measures

The cost of radiotherapy in a decade of technology evolution

International Nuclear Information System (INIS)

Van de Werf, Evelyn; Verstraete, Jan; Lievens, Yolande

2012-01-01

Purpose: To quantify changes in radiotherapy costs occurring in a decade of medical–technological evolution. Materials and methods: The activity-based costing (ABC) model of University Hospitals Leuven (UHL) radiotherapy (RT) department was adapted to current RT standards. It allocated actual resource costs to the treatments based on the departmental work-flow and patient mix in 2009. A benchmark with the former model analyzed the cost increases related to changes in RT infrastructure and practice over 10 years. Results: A considerable increase in total RT costs was observed, resulting from higher capital investments (96%) and personnel cost (103%), the latter dominating the total picture. Treatment delivery remains the most costly activity, boosted by the cost of improved quality assurance (QA), 23% of total product costs, coming along with more advanced RT techniques. Hence, cost increases at the product level are most obvious for complex treatments, such as intensity-modulated radiotherapy (IMRT), representing cost increases ranging between 38% and 88% compared to conformal approaches. Conclusions: The ABC model provides insight into the financial consequences of evolving technology and practice. Such data are a mandatory first step in our strive to prove RT cost-effectiveness and thus support optimal reimbursement and provision of radiotherapy departments.

Radiotherapy

International Nuclear Information System (INIS)

Wannenmacher, M.; Debus, J.; Wenz, F.

2006-01-01

The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy

Emerging paradigm in radiobiology in concept and practices of hypo fractionated conformal radiotherapy

International Nuclear Information System (INIS)

Mishra, S.P.; Srivastava, Anoop Kumar; Rastogi, Madhup; Khurana, Rohini; Pawaskar, Asawari

2016-01-01

This study has been performed in clinical setting by creating the treatment plan in dynamic conformal arc mode as the treatment delivery technique; with add on collimator APEX system having 56 pairs of 2.5 mm each as treatment unit. Photon beam energy selected for the study was 6 MV. Various number of treatment arcs were applied depending upon the location of the PTV. The PTV was prescribed a total dose of 60 Gy in five fractions

Bystander effects and radiotherapy.

Science.gov (United States)

Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

2015-01-01

Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy.

Comparison between intensity modulated radiotherapy (IMRT) and 3D tangential beams technique used in patients with early-stage breast cancer who received breast-conserving therapy

International Nuclear Information System (INIS)

Sas-Korczynska, B.; Kokoszka, A.; Korzeniowski, S.; Sladowska, A.; Rozwadowska-Bogusz, B.; Lesiak, J.; Dyczek, S.

2010-01-01

Background: The most often found complications in patients with breast cancer who received radiotherapy are cardiac and pulmonary function disorders and development of second malignancies. Aim: To compare the intensity modulated radiotherapy with the 3D tangential beams technique in respect of dose distribution in target volume and critical organs they generate in patients with early-stage breast cancer who received breast-conserving therapy. Materials and methods: A dosimetric analysis was performed to assess the three radiotherapy techniques used in each of 10 consecutive patients with early-stage breast cancer treated with breast-conserving therapy. Radiotherapy was planned with the use of all the three techniques: 3D tangential beams with electron boost, IMRT with electron boost, and intensity modulated radiotherapy with simultaneous integrated boost. Results: The use of the IMRT techniques enables more homogenous dose distribution in target volume. The range of mean and median dose to the heart and lung was lower with the IMRT techniques in comparison to the 3D tangential beams technique. The range of mean dose to the heart amounted to 0.3 - 3.5 Gy for the IMRT techniques and 0.4 - 4.3 for the tangential beams technique. The median dose to the lung on the irradiated side amounted to 4.9 - 5 Gy for the IMRT techniques and 5.6 Gy for the 3D tangential beams technique. Conclusion: The application of the IMRT techniques in radiotherapy patients with early-stage breast cancer allows to obtain more homogenous dose distribution in target volume, while permitting to reduce the dose to critical organs. (authors)

Clinical utility of RapidArc™ radiotherapy technology

International Nuclear Information System (INIS)

Infusino, Erminia

2015-01-01

RapidArc™ is a radiation technique that delivers highly conformal dose distributions through the complete rotation (360°) and speed variation of the linear accelerator gantry. This technique, called volumetric modulated arc therapy (VMAT), compared with conventional radiotherapy techniques, can achieve high-target volume coverage and sparing damage to normal tissues. RapidArc delivers precise dose distribution and conformity similar to or greater than intensity-modulated radiation therapy in a short time, generally a few minutes, to which image-guided radiation therapy is added. RapidArc has become a currently used technology in many centers, which use RapidArc technology to treat a large number of patients. Large and small hospitals use it to treat the most challenging cases, but more and more frequently for the most common cancers. The clinical use of RapidArc and VMAT technology is constantly growing. At present, a limited number of clinical data are published, mostly concerning planning and feasibility studies. Clinical outcome data are increasing for a few tumor sites, even if only a little. The purpose of this work is to discuss the current status of VMAT techniques in clinical use through a review of the published data of planning systems and clinical outcomes in several tumor sites. The study consisted of a systematic review based on analysis of manuscripts retrieved from the PubMed, BioMed Central, and Scopus databases by searching for the keywords “RapidArc”, “Volumetric modulated arc radiotherapy”, and “Intensity-modulated radiotherapy”

Left-sided breast cancer and risks of secondary lung cancer and ischemic heart disease. Effects of modern radiotherapy techniques

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Corradini, Stefanie; Ballhausen, Hendrik; Weingandt, Helmut; Freislederer, Philipp; Schoenecker, Stephan; Niyazi, Maximilian; Belka, Claus [University Hospital, LMU Munich, Department of Radiation Oncology, Munich (Germany); Simonetto, Cristoforo; Eidemueller, Markus [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Neuherberg (Germany); Ganswindt, Ute [University Hospital, LMU Munich, Department of Radiation Oncology, Munich (Germany); Medical University, Department of Radiation Oncology, Innsbruck (Austria)

2018-03-15

Modern breast cancer radiotherapy techniques, such as respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) or volumetric-modulated arc radiotherapy (VMAT) have been shown to reduce the high dose exposure of the heart in left-sided breast cancer. The aim of the present study was to comparatively estimate the excess relative and absolute risks of radiation-induced secondary lung cancer and ischemic heart disease for different modern radiotherapy techniques. Four different treatment plans were generated for ten computed tomography data sets of patients with left-sided breast cancer, using either three-dimensional conformal radiotherapy (3D-CRT) or VMAT, in free-breathing (FB) or DIBH. Dose-volume histograms were used for organ equivalent dose (OED) calculations using linear, linear-exponential, and plateau models for the lung. A linear model was applied to estimate the long-term risk of ischemic heart disease as motivated by epidemiologic data. Excess relative risk (ERR) and 10-year excess absolute risk (EAR) for radiation-induced secondary lung cancer and ischemic heart disease were estimated for different representative baseline risks. The DIBH maneuver resulted in a significant reduction of the ERR and estimated 10-year excess absolute risk for major coronary events compared to FB in 3D-CRT plans (p = 0.04). In VMAT plans, the mean predicted risk reduction through DIBH was less pronounced and not statistically significant (p = 0.44). The risk of radiation-induced secondary lung cancer was mainly influenced by the radiotherapy technique, with no beneficial effect through DIBH. VMAT plans correlated with an increase in 10-year EAR for radiation-induced lung cancer as compared to 3D-CRT plans (DIBH p = 0.007; FB p = 0.005, respectively). However, the EARs were affected more strongly by nonradiation-associated risk factors, such as smoking, as compared to the choice of treatment technique. The results indicate that 3D-CRT plans in DIBH pose the lowest

Conformational Analysis of Misfolded Protein Aggregation by FRET and Live-Cell Imaging Techniques

Directory of Open Access Journals (Sweden)

Akira Kitamura

2015-03-01

Full Text Available Cellular homeostasis is maintained by several types of protein machinery, including molecular chaperones and proteolysis systems. Dysregulation of the proteome disrupts homeostasis in cells, tissues, and the organism as a whole, and has been hypothesized to cause neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS and Huntington’s disease (HD. A hallmark of neurodegenerative disorders is formation of ubiquitin-positive inclusion bodies in neurons, suggesting that the aggregation process of misfolded proteins changes during disease progression. Hence, high-throughput determination of soluble oligomers during the aggregation process, as well as the conformation of sequestered proteins in inclusion bodies, is essential for elucidation of physiological regulation mechanism and drug discovery in this field. To elucidate the interaction, accumulation, and conformation of aggregation-prone proteins, in situ spectroscopic imaging techniques, such as Förster/fluorescence resonance energy transfer (FRET, fluorescence correlation spectroscopy (FCS, and bimolecular fluorescence complementation (BiFC have been employed. Here, we summarize recent reports in which these techniques were applied to the analysis of aggregation-prone proteins (in particular their dimerization, interactions, and conformational changes, and describe several fluorescent indicators used for real-time observation of physiological states related to proteostasis.

Cervix carcinomas: place of intensity-modulated radiotherapy; Les cancers du col uterin: place de la radiotherapie avec modulation d'intensite

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Barillot, I. [Centre Regional Universitaire de Cancerologie H.S.-Kaplan, Hopital Bretonneau, CHU de Tours, 37 - Tours (France); Universite Francois-Rabelais, 37 - Tours (France)

2009-10-15

While indications of modulated intensity radiation therapy (I.M.R.T.) are perfectly defined in head and neck and prostate cancer patients, this technique remains under evaluation for gynecologic tumours. The implementation of conformal three dimensional radiotherapy in the late 1990 has been the first important step for optimisation of treatment of cervix carcinomas, as it permitted a better target coverage with a significant reduction of the bladder dose. However, this technique often leads to an irradiation of a larger volume of rectum in locally advanced stages and could only spare a limited amount of intestine. I.R.M.T. is one of the optimisation methods potentially efficient for a better sparing of digestive tract during irradiation of cervix carcinomas. The aim of this literature review is to provide the arguments supporting this hypothesis, and to define the place of this technique for dose escalation. (authors)

Major Late Toxicities After Conformal Radiotherapy for Nasopharyngeal Carcinoma-Patient- and Treatment-Related Risk Factors

International Nuclear Information System (INIS)

Lee, Anne W.M.; Ng, W.T.; Hung, W.M.; Choi, C.W.; Tung, Raymond; Ling, Y.H.; Cheng, Peter T.C.; Yau, T.K.; Chang, Amy T.Y.; Leung, Samuel K.C.; Lee, Michael C.H.; Bentzen, Soren M.

2009-01-01

Purpose: To retrospectively analyze the factors affecting late toxicity for nasopharyngeal carcinoma. Methods and Materials: Between 1998 and 2003, 422 patients were treated with a conformal technique with 2-Gy daily fractions to a total dose of 70 Gy. Conventional fractionation (5 fractions weekly) was used in 232 patients and accelerated fractionation (6 fractions weekly) in 190 patients. One hundred seventy-one patients were treated with the basic radiotherapy course alone (Group 1), 55 patients had an additional boost of 5 Gy in 2 fractions (Group 2), and 196 patients underwent concurrent cisplatin-based chemotherapy (Group 3). Results: The 5-year overall toxicity rate was significantly greater in Group 3 than in Group 1 (37% vs. 27%, p = 0.009). Although the overall rate in Group 2 was not elevated (28% vs. 27%, p = 0.697), a significant increase in temporal lobe necrosis was observed (4.8% vs. 0%, p = 0.015). Multivariate analyses showed that age and concurrent chemotherapy were significant factors. The hazard ratio of overall toxicity attributed to chemotherapy was 1.99 (95% confidence interval, 1.32-2.99, p = 0.001). The mean radiation dose to the cochlea was another significant factor affecting deafness, with a hazard ratio of 1.03 (95% confidence interval, 1.01-1.05, p = 0.005) per 1-Gy increase. The cochlea that received >50 Gy had a significantly greater deaf rate (Group 1, 18% vs. 7%; and Group 3, 22% vs. 14%). Conclusion: The therapeutic margin for nasopharyngeal carcinoma is extremely narrow, and a significant increase in brain necrosis could result from dose escalation. The significant factors affecting the risk of deafness included age, concurrent chemoradiotherapy, and greater radiation dose to the cochlea

Conformal intensity-modulated radiotherapy (IMRT) delivered by robotic linac - testing IMRT to the limit?

International Nuclear Information System (INIS)

Webb, S.

1999-01-01

In this paper it is proposed that intensity-modulated radiotherapy (IMRT) could be delivered optimally by a short-length linac mounted on a robotic arm. The robot would allow the linac to 'plant' narrow pencils of photon radiation with any orientation (excluding zones within which the linac and couch might collide) relative to the planning target volume (PTV). The treatment is specified by the trajectory of the robot and by the number of monitor units (MUs) delivered at each robotic orientation. An inverse-planning method to determine the optimum robotic trajectory is presented. It is shown that for complex PTVs, specifically those with concavities in their outline, the conformality of the treatment is improved by the use of a complex trajectory in comparison with a less complex constrained trajectory and this improvement is quantified. It is concluded that robotic linac delivery would lead to a great flexibility in those IMRT treatments requiring very complicated dose distributions with complex 3D shapes. However, even using very fast computers, the goal of determining whether robotic linac delivery is the ultimate IMRT cannot be conclusively reached at present. (author)

Assessment of renal function after conformal radiotherapy and intensity-modulated radiotherapy by functional {sup 1}H-MRI and {sup 23}Na-MRI