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Sample records for boost radiotherapy planned

  1. CT planning of boost irradiation in radiotherapy of breast cancer after conservative surgery

    International Nuclear Information System (INIS)

    Messer, Peter M.; Kirikuta, Ion C.; Bratengeier, Klaus; Flentje, Michael

    1997-01-01

    Background and purpose: A study was performed to compare the accuracy of clinical treatment set-up and CT planning of boost irradiation in radiotherapy of breast cancer. Material and methods: Between September 1993 and October 1994, 45 women who underwent breast conserving surgery and irradiation containing a boost to the tumour bed were investigated. Prospective evaluation of CT planning of the boost was carried out. The target volume/boost field, electron energy and treatment set-up had been defined on the basis of clinical examination, initial and postsurgical mammograms by one radiotherapist. Next, a planning CT was performed in treatment position and a CT-based treatment plan was calculated according to a target volume defined by another radiotherapist. The clinical treatment set-up was imported into our computer planning system and the resulting isodose plots were compared with those from CT planning and reviewed critically. Results: The clinically defined treatment set-up had to be modified in 80% of the patients. Most discrepancies observed were related to the size of the boost field itself and the chosen electron energy. Minor changes had to be made with respect to angle of table and gantry. Conclusions: Critical review of the isodose plots from both methods showed clear advantages for CT planning. Guidelines for target definition in CT planning of boost irradiation and subgroups of patients benefiting from this technique are described

  2. Whole Brain Radiotherapy With Hippocampal Avoidance and Simultaneously Integrated Brain Metastases Boost: A Planning Study

    International Nuclear Information System (INIS)

    Gutierrez, Alonso N.; Westerly, David C.; Tome, Wolfgang A.; Jaradat, Hazim A..; Mackie, Thomas R.; Bentzen, Soren M.; Khuntia, Deepak; Mehta, Minesh P.

    2007-01-01

    Purpose: To evaluate the feasibility of using tomotherapy to deliver whole brain radiotherapy with hippocampal avoidance, hypothesized to reduce the risk of memory function decline, and simultaneously integrated boost to brain metastases to improve intracranial tumor control. Methods and Materials: Ten patients treated with radiosurgery and whole brain radiotherapy underwent repeat planning using tomotherapy with the original computed tomography scans and magnetic resonance imaging-computed tomography fusion-defined target and normal structure contours. The individually contoured hippocampus was used as a dose-limiting structure ( 2 and 5.8 ± 1.9 Gy 2 for 2.5- and 1.0-cm FW, respectively. The mean treatment delivery time for the 2.5- and 1.0-cm FW plans was 10.2 ± 1.0 and 21.8 ± 1.8 min, respectively. Conclusion: Composite tomotherapy plans achieved three objectives: homogeneous whole brain dose distribution equivalent to conventional whole brain radiotherapy; conformal hippocampal avoidance; and radiosurgically equivalent dose distributions to individual metastases

  3. Boosting runtime-performance of photon pencil beam algorithms for radiotherapy treatment planning.

    Science.gov (United States)

    Siggel, M; Ziegenhein, P; Nill, S; Oelfke, U

    2012-10-01

    Pencil beam algorithms are still considered as standard photon dose calculation methods in Radiotherapy treatment planning for many clinical applications. Despite their established role in radiotherapy planning their performance and clinical applicability has to be continuously adapted to evolving complex treatment techniques such as adaptive radiation therapy (ART). We herewith report on a new highly efficient version of a well-established pencil beam convolution algorithm which relies purely on measured input data. A method was developed that improves raytracing efficiency by exploiting the capability of modern CPU architecture for a runtime reduction. Since most of the current desktop computers provide more than one calculation unit we used symmetric multiprocessing extensively to parallelize the workload and thus decreasing the algorithmic runtime. To maximize the advantage of code parallelization, we present two implementation strategies - one for the dose calculation in inverse planning software, and one for traditional forward planning. As a result, we could achieve on a 16-core personal computer with AMD processors a superlinear speedup factor of approx. 18 for calculating the dose distribution of typical forward IMRT treatment plans. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  4. 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

  5. Effect on therapeutic ratio of planning a boosted radiotherapy dose to the dominant intraprostatic tumour lesion within the prostate based on multifunctional MR parameters

    Science.gov (United States)

    Payne, G S; deSouza, N M; Dearnaley, D; Morgan, V A; Morgan, S C; Partridge, M

    2014-01-01

    Objective: To demonstrate the feasibility of an 8-Gy focal radiation boost to a dominant intraprostatic lesion (DIL), identified using multiparametric MRI (mpMRI), and to assess the potential outcome compared with a uniform 74-Gy prostate dose. Methods: The DIL location was predicted in 23 patients using a histopathologically verified model combining diffusion-weighted imaging, dynamic contrast-enhanced imaging, T2 maps and three-dimensional MR spectroscopic imaging. The DIL defined prior to neoadjuvant hormone downregulation was firstly registered to MRI-acquired post-hormone therapy and subsequently to CT radiotherapy scans. Intensity-modulated radiotherapy (IMRT) treatment was planned for an 8-Gy focal boost with 74-Gy dose to the remaining prostate. Areas under the dose–volume histograms (DVHs) for prostate, bladder and rectum, the tumour control probability (TCP) and normal tissue complication probabilities (NTCPs) were compared with those of the uniform 74-Gy IMRT plan. Results: Deliverable IMRT plans were feasible for all patients with identifiable DILs (20/23). Areas under the DVHs were increased for the prostate (75.1 ± 0.6 vs 72.7 ± 0.3 Gy; p < 0.001) and decreased for the rectum (38.2 ± 2.5 vs 43.5 ± 2.5 Gy; p < 0.001) and the bladder (29.1 ± 9.0 vs 36.9 ± 9.3 Gy; p < 0.001) for the boosted plan. The prostate TCP was increased (80.1 ± 1.3 vs 75.3 ± 0.9 Gy; p < 0.001) and rectal NTCP lowered (3.84 ± 3.65 vs 9.70 ± 5.68 Gy; p = 0.04) in the boosted plan. The bladder NTCP was negligible for both plans. Conclusion: Delivery of a focal boost to an mpMRI-defined DIL is feasible, and significant increases in TCP and therapeutic ratio were found. Advances in knowledge: The delivery of a focal boost to an mpMRI-defined DIL demonstrates statistically significant increases in TCP and therapeutic ratio. PMID:24601648

  6. Treatment planning strategy for whole-brain radiotherapy with hippocampal sparing and simultaneous integrated boost for multiple brain metastases using intensity-modulated arc therapy

    International Nuclear Information System (INIS)

    Pokhrel, Damodar; Sood, Sumit; McClinton, Christopher; Shen, Xinglei; Lominska, Christopher; Saleh, Habeeb; Badkul, Rajeev; Jiang, Hongyu; Mitchell, Melissa; Wang, Fen

    2016-01-01

    Purpose: To retrospectively evaluate the accuracy, plan quality and efficiency of intensity-modulated arc therapy (IMAT) for hippocampal sparing whole-brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in patients with multiple brain metastases (m-BM). Materials and methods: A total of 5 patients with m-BM were retrospectively replanned for HS-WBRT with SIB using IMAT treatment planning. The hippocampus was contoured on diagnostic T1-weighted magnetic resonance imaging (MRI) which had been fused with the planning CT image set. The hippocampal avoidance zone (HAZ) was generated using a 5-mm uniform margin around the paired hippocampi. The m-BM planning target volumes (PTVs) were contoured on T1/T2-weighted MRI registered with the 3D planning computed tomography (CT). The whole-brain planning target volume (WB-PTV) was defined as the whole-brain tissue volume minus HAZ and m-BM PTVs. Highly conformal IMAT plans were generated in the Eclipse treatment planning system for Novalis-TX linear accelerator consisting of high-definition multileaf collimators (HD-MLCs: 2.5-mm leaf width at isocenter) and 6-MV beam. Prescription dose was 30 Gy for WB-PTV and 45 Gy for each m-BM in 10 fractions. Three full coplanar arcs with orbit avoidance sectors were used. Treatment plans were evaluated using homogeneity (HI) and conformity indices (CI) for target coverage and dose to organs at risk (OAR). Dose delivery efficiency and accuracy of each IMAT plan was assessed via quality assurance (QA) with a MapCHECK device. Actual beam-on time was recorded and a gamma index was used to compare dose agreement between the planned and measured doses. Results: All 5 HS-WBRT with SIB plans met WB-PTV D 2% , D 98% , and V 30 Gy NRG-CC001 requirements. The plans demonstrated highly conformal and homogenous coverage of the WB-PTV with mean HI and CI values of 0.33 ± 0.04 (range: 0.27 to 0.36), and 0.96 ± 0.01 (range: 0.95 to 0.97), respectively. All 5 hippocampal sparing

  7. PLANNING NATIONAL RADIOTHERAPY SERVICES

    Directory of Open Access Journals (Sweden)

    Eduardo eRosenblatt

    2014-11-01

    Full Text Available Countries, states and island nations often need forward planning of their radiotherapy services driven by different motives. Countries without radiotherapy services sponsor patients to receive radiotherapy abroad. They often engage professionals for a feasibility study in order to establish whether it would be more cost-beneficial to establish a radiotherapy facility. Countries where radiotherapy services have developed without any central planning, find themselves in situations where many of the available centres are private and thus inaccessible for a majority of patients with limited resources. Government may decide to plan ahead when a significant exodus of cancer patients travel to another country for treatment, thus exposing the failure of the country to provide this medical service for its citizens. In developed countries the trigger has been the existence of highly visible waiting lists for radiotherapy revealing a shortage of radiotherapy equipment.This paper suggests that there should be a systematic and comprehensive process of long-term planning of radiotherapy services at the national level, taking into account the regulatory infrastructure for radiation protection, planning of centres, equipment, staff, education pr

  8. Radiotherapy Boost Following Conservative Surgery for Locally Advanced Breast Cancer

    International Nuclear Information System (INIS)

    Cendales, Ricardo; Ospino, Rosalba; Torres, Felipe; Cotes, Martha

    2009-01-01

    Nearly half of breast cancer patients in developing countries present with a locally advanced cancer. Treatment is centered on a multimodal approach based on chemotherapy, surgery and radiotherapy. The growing use of neoadjuvant chemotherapy has led to a more conservative surgical approach; nonetheless, it is not yet considered as a standard. There are no clear recommendations on the use of a radiotherapy boost in such situation. A Medline search was developed. Most articles are retrospective series. Survival free of locoregional relapse in patients treated with neoadjuvant chemotherapy, breast conserving surgery and radiotherapy is good. All articles described a boost administered to nearly all patients without regard to their prognostic factors, given that a locally advanced tumor is already considered as a poor prognostic factor. Even tough the poor level of evidence, a recommendation can be made: radiotherapy boost should be administered to all patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and breast conserving surgery.

  9. Concurrent Boost with Adjuvant Breast Hypofractionated Radiotherapy and Toxicity Assessment

    Directory of Open Access Journals (Sweden)

    Mona M. Sayed

    2015-01-01

    Full Text Available Background: The use of shorter radiotherapy schedules has an economic and logistic advantage for radiotherapy departments, as well as a high degree of patient convenience. The aim of this study is to assess the acute and short-term late toxicities of a hypofractionated radiotherapy schedule with a concomitant boost. Methods: We enrolled 57 eligible patients as group A. These patients received 42.5 Gy in 16 fractions of 2.66 Gy each to the whole breast over 3.2 weeks. A concomitant electron boost of 12 Gy in 16 fractions was also administered which gave an additional 0.75 Gy daily to the lumpectomy area for a total radiation dose of 54.5 Gy. Toxicity was recorded at three weeks and at three months for this group as well as for a control group (group B. The control group comprised 76 eligible patients treated conventionally with 50 Gy to the whole breast over five weeks followed by a sequential electron boost of 12 Gy in 2 Gy per fraction. Results: There were no statistically significant differences observed in the incidence of acute skin toxicity, breast pain, and edema recorded at three weeks or pigmentation and fibrosis recorded at three months between the two groups (P0.05. Conclusion: The results of this study suggest there are no increased acute and shortterm late toxicities affiliated with the hypofractionated schedule plus a concomitant boost as prescribed compared to the conventional fractionation of adjuvant breast radiotherapy. Large randomized trials and long-term follow-up are needed to confirm these favorable findings.

  10. 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)

  11. Concomitant boost radiotherapy for squamous carcinoma of the tonsillar fossa

    International Nuclear Information System (INIS)

    Gwozdz, John T.; Morrison, William H.; Garden, Adam S.; Weber, Randal S.; Peters, Lester J.; Ang, K. Kian

    1997-01-01

    Purpose: To assess the efficacy of a concomitant boost fractionation schedule of radiotherapy for treating patients with squamous carcinoma of the tonsillar fossa. Patients and Methods: Between December 1983 and November 1992, 83 patients with squamous carcinoma of the tonsil were treated with concomitant boost fractionation. The distribution of American Joint Committee on Cancer T stages was TX-4, T1-5, T2-29, T3-41, T4-4; N stages were NX-1, N0-26, N1-13, N2-31, N3-12. Patients were treated with standard large fields to 54 Gy in 6 weeks. The boost treatment consisted of a second daily 1.5 Gy fraction for 10-12 fractions, usually delivered during the final phase of treatment. The tumor dose was 69-72 Gy, given over 6 weeks. Twenty-one patients, who all had N2 or N3 regional disease, underwent neck dissections, either before (13 patients) or 6 weeks after radiotherapy (8 patients); the other patients were treated with radiotherapy alone. Results: The 5-year actuarial disease-specific survival and overall survival rates were 71 and 60%, respectively. Patients with T2 and T3 primary tumors had 5-year actuarial local control rates of 96 and 78%, respectively. Patients with T3 disease who received the final-phase boost had a 5-year actuarial local control rate of 82%. Actuarial 5-year regional disease control rates were N0, 92%; N1, 76%; N2, 89%; and N3, 89%. The 21 patients who had neck dissections all had their disease regionally controlled. Patients presenting with nodal disease or after a node excision who were treated with radiation alone had a 5-year actuarial regional disease control rate of 79%. All but five patients had confluent Grade 4 mucositis during treatment. Severe late complications attributable to radiation included mandibular necrosis, in-field osteosarcoma, and chronic dysphagia for solid foods. Conclusions: High rates of local and regional disease control were achieved with the concomitant boost fractionation schedule, with few cases of severe late

  12. 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).

  13. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

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    Turley, Jessica; Claridge Mackonis, Elizabeth [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales (Australia)

    2015-09-15

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging.

  14. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    International Nuclear Information System (INIS)

    Turley, Jessica; Claridge Mackonis, Elizabeth

    2015-01-01

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging

  15. Fractionated stereotactic radiotherapy boost after post-operative radiotherapy in patients with high-grade gliomas

    International Nuclear Information System (INIS)

    Baumert, Brigitta G.; Lutterbach, Johannes; Bernays, Rene; Davis, J. Bernard; Heppner, Frank L.

    2003-01-01

    Purpose: To determine the value and the toxicity of an additional fractionated stereotactic boost as used in the joint randomized EORTC-22972/MRC-BR10 study in patients with malignant gliomas. Materials and methods: Seventeen patients (11 male, six female) with a high-grade glioma (two WHO III, 15 WHO IV) ≤4 cm in maximum diameter, with a good performance status (WHO ≥2), were treated with a fractionated stereotactic radiotherapy (SRT) boost to 20 Gy in four fractions following partial brain irradiation to a dose of 60 Gy in 30 fractions. This patient group was compared with historical data in a matched-pair analysis. Results: All patients were treated by conventional radiotherapy and a SRT boost (15 patients received 20 Gy and two patients 10 Gy). Acute side effects included fatigue (two), impairment of short-term memory (one) and worsening of pre-existing symptoms (one). No patient developed steroid dependence after SRT. One patient was re-operated for radiation necrosis. At a median follow-up of 25 months (9-50 months) 14 patients recurred locally. Survival was 77% at 1 year and 42% at 2 years; progression-free survival was 70% at 1 year and 35% at 2 years for all patients, respectively. Median survival for the whole patient group is 20 months. Comparison with a matched historical group showed a significantly better survival for the group treated with a stereotactic boost (P<0.0001). Conclusion: A fractionated stereotactic boost after standard external beam radiotherapy in selected patients with high-grade glioma is feasible and well tolerated with low toxicity. Compared to historical data survival is significantly better with an additional SRT boost. However, its effectiveness has to be proven in a randomized trial

  16. Sequentially delivered boost plans are superior to simultaneously delivered plans in head and neck cancer when the boost volume is located further away from the parotid glands

    International Nuclear Information System (INIS)

    Lamers-Kuijper, Emmy; Heemsbergen, Wilma; Mourik, Anke van; Rasch, Coen

    2011-01-01

    Purpose: To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare the salivary glands. Methods and materials: We evaluated 50 recently treated head and neck cancer patients. Apart from the clinical plan with a sequentially (SEQ) given boost using an Intensity Modulated Radiotherapy Technique (IMRT), a simultaneous integrated boost (SIB) technique plan was constructed with the same beam set-up. The mean dose to the parotid glands was calculated and compared. The elective nodal areas were bilateral in all cases, with a boost on either one side or both sides of the neck. Results: When the parotid gland volume and the Planning Target Volume (PTV) for the boost overlap there is on average a lower dose to the parotid gland with a SIB technique (-1.2 Gy), which is, however, not significant (p = 0.08). For all parotid glands with no boost PTV overlap, there is a benefit from a SEQ technique compared to a SIB technique for the gland evaluated (on average a 2.5 Gy lower dose to the parotid gland, p < 0.001). When the distance between gland and PTV is 0-1 cm, this difference is on average 0.8 Gy, for 1-2 cm distance 2.9 Gy and for glands with a distance greater than 2 cm, 3.3 Gy. When the lymph nodes on the evaluated side are also included in the boost PTV, however, this relationship between the distance and the gain of a SEQ seems less clear. Conclusions: A sequentially delivered boost technique results in a better treatment plan for most cases, compared to a simultaneous integrated boost IMRT technique, if the boost PTV is more than 1 cm away from at least one parotid gland.

  17. Using injectable hydrogel markers to assess resimulation for boost target volume definition in a patient undergoing whole-breast radiotherapy

    International Nuclear Information System (INIS)

    Patel, Henal; Goyal, Sharad; Kim, Leonard

    2015-01-01

    Several publications have recommended that patients undergoing whole-breast radiotherapy be resimulated for boost planning. The rationale for this is that the seroma may be smaller when compared with the initial simulation. However, the decision remains whether to use the earlier or later images to define an appropriate boost target volume. A patient undergoing whole-breast radiotherapy had new, injectable, temporary hydrogel fiducial markers placed 1 to 3 cm from the seroma at the time of initial simulation. The patient was resimulated 4.5 weeks later for conformal photon boost planning. Computed tomography (CT) scans acquired at the beginning and the end of whole-breast radiotherapy showed that shrinkage of the lumpectomy cavity was not matched by a corresponding reduction in the surrounding tissue volume, as demarcated by hydrogel markers. This observation called into question the usual interpretation of cavity shrinkage for boost target definition. For this patient, it was decided to define the boost target volume on the initial planning CT instead of the new CT.

  18. Ballistic optimisation with intensity modulation with integration of a concomitant boost for the radiotherapy of glioblastomas

    International Nuclear Information System (INIS)

    Supper, C.; Franceries, X.; Supper, C.; Vieillevigne, L.; Ken, S.; Simon, L.; Rives, M.; Moyal, E.; Delannes, M.; Noel, A.; Laprie, A.; Franceries, X.; Ken, S.; Laprie, A.; Noel, A.

    2010-01-01

    The authors report a study aimed at the optimisation of the ballistics of intensity-modulated conformation radiotherapy (IMRT) treatment with a boost for the preparation of a multi-centric prospective trial financed by a program on glioblastoma treatment. This treatment consists in using the boost technique to obtain an increase of the dose delivered by the IMRT in sites presenting a strong predictive value for relapse. These sites are defined by means of magnetic resonance spectrometric imagery. Conformation indexes, planning target volumes, doses delivered to organs at risk are analysed. The proximity of organs at risk was the main difficulty, but a good dosimetry has been obtained with the use of five coplanar beams. Short communication

  19. Use of boost radiotherapy in oncoplastic breast-conserving surgery - a systematic review.

    Science.gov (United States)

    Schaverien, M V; Stallard, S; Dodwell, D; Doughty, J C

    2013-11-01

    The use of local boost radiotherapy to the tumour bed has been demonstrated in randomised-controlled trials to reduce local recurrence rates following breast-conserving surgery (BCS) and is the standard of care. Oncoplastic BCS techniques with parenchymal rearrangement present new challenges to the localisation of the tumour bed and therefore delivery of local boost radiotherapy. The aim of this review was to evaluate the reporting of boost radiotherapy in the oncoplastic BCS literature. Pubmed, Ovid MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched for studies reporting oncoplastic BCS using volume displacement techniques. 24 studies met the inclusion criteria (n = 1933 patients). Use of boost radiotherapy was reported in 11 studies, in 2 of which it was for the treatment of incomplete or close margins, and marking of the tumour bed was only reported in 8 studies. None of the studies reported the number of patients where the tumour bed could not be localised. The use of local boost radiotherapy and tumour bed marking was not reported in the majority of studies of oncoplastic BCS. Future studies need to provide detailed information regarding the use of boost radiotherapy and difficulties determining the target volume so that current radiotherapy approaches can be reviewed and improved for these advanced techniques. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Computerised tomography in radiotherapy planning

    International Nuclear Information System (INIS)

    Badcock, P.C.

    1983-01-01

    This study evaluates the effectiveness of computed tomography as an adjunct to radiotherapy planning. Until recently, acquisition of accurate data concerning tumour anatomy lagged behind other developments in radiotherapy. With the advent of computer-tomography (CT), these data can be displayed and transmitted to a treatment planning computer. It is concluded that the greatest inaccuracies in the radiation treatment of patients are to be found in both the inadequate delineation of the target volume within the patient and changes in body outline relative to the target volume over the length of the irradiated volume. The technique was useful in various subgroups (pelvic, intra-thoracic and chest-wall tumours) and for those patients being treated palliatively. With an estimated improvement in cure rate of 4.5% and cost-effective factors of between 3.3 and 5, CT-assisted radiotherapy planning appears to be a worthwhile procedure. (orig.)

  1. Construction of a remote radiotherapy planning system

    International Nuclear Information System (INIS)

    Ogawa, Yoshihiro; Nemoto, Kenji; Takahashi, Chiaki; Takai, Yoshihiro; Yamada, Shogo; Seiji, Hiromasa; Sasaki, Kazuya

    2005-01-01

    We constructed a remote radiotherapy planning system, and we examined the usefulness of and faults in our system in this study. Two identical radiotherapy planning systems, one installed at our institution and the other installed at an affiliated hospital, were used for radiotherapy planning. The two systems were connected by a wide area network (WAN), using a leased line. Beam data for the linear accelerator at the affiliated hospital were installed in the two systems. During the period from December 2001 to December 2002, 43 remote radiotherapy plans were made using this system. Data were transmitted using a file transfer protocol (FTP) software program. The 43 radiotherapy plans examined in this study consisted of 13 ordinary radiotherapy plans, 28 radiotherapy plans sent to provide assistance for medical residents, and 2 radiotherapy plans for emergency cases. There were ten minor planning changes made in radiotherapy plans sent to provide assistance for medical residents. Our remote radiotherapy planning system based on WAN using a leased line is useful for remote radiotherapy, with advantages for both radiation oncologists and medical residents. (author)

  2. Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

    International Nuclear Information System (INIS)

    Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond

    2005-01-01

    Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

  3. Comparing of dose distribution between intensity-modulated radiotherapy simultaneous integrated boost and conventional radiotherapy for cervical cancer patients

    International Nuclear Information System (INIS)

    Zhu Lihong; Xu Bo; Wu Hao; Su Xing; Han Shukui

    2009-01-01

    Objective: To assess the feasibility of applying intensity-modulated radiotherapy (IMRT) simultaneous integrated boost (SIB) to replace conventional radiotherapy (CR) plus brachytherapy of whole pelvis in locally advanced cervical cancer (LACC). Methods: Five LACC patients based difference position of uterus were chosen and worked out CR and IMRT SIB plans respectively. Dose distributions were compared between IMRT SIB and CR. Results: When uterus was in ante-,neutral-, retro-pnsition and deviation respectively, IMRT SIB could provide enough and homogeneous dose distribution for target volume and reduce irradiated volumes and doses for organs at risk (recta, bladder and small intestine) than CR. The doses of the A, B, and fundus of uterus were higher in IMRT SIB than CR. However, in ease of small intestine was close to or encircled the uterus, the targets volume dose would be inadequacy. Conclusions: LACC IMRT SIB's dose distribution is better than CR (except excess ante-position) and may help to treat those patients who couldn't be suitable with brachytherapy. (authors)

  4. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

    OpenAIRE

    Ken, Sol?akh?na; Vieillevigne, Laure; Franceries, Xavier; Simon, Luc; Supper, Caroline; Lotterie, Jean-Albert; Filleron, Thomas; Lubrano, Vincent; Berry, Isabelle; Cassol, Emmanuelle; Delannes, Martine; Celsis, Pierre; Cohen-Jonathan, Elizabeth Moyal; Laprie, Anne

    2013-01-01

    Abstract Background To integrate 3D MR spectroscopy imaging (MRSI) in the treatment planning system (TPS) for glioblastoma dose painting to guide simultaneous integrated boost (SIB) in intensity-modulated radiation therapy (IMRT). Methods For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT), one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integr...

  5. EORTC 22972-26991/MRC BR10 trial: Fractionated stereotactic boost following conventional radiotherapy of high grade gliomas

    International Nuclear Information System (INIS)

    Baumert, Brigitta G.; Brada, Michael; Bernier, Jacques; Kortmann, Rolf D.; Dehing-Oberije, Cary; Collette, Laurence; Davis, J. Bernard

    2008-01-01

    Background and purpose: The EORTC trial No. 22972 investigated the role of an additional fractionated stereotactic boost (fSRT) to conventional radiotherapy for patients with high grade gliomas. A quality-assurance (QA) programme was run in conjunction with the study and was the first within the EORTC addressing the quality of a supposedly highly accurate treatment technique such as stereotactic radiotherapy. A second aim was to investigate a possible relation between the clinical results of the stereotactic boost arm and the results of the QA. Materials and methods: The trial was closed in 2001 due to low accrual. In total, 25 patients were randomized: 14 into the experimental arm and 11 into the control arm. Six centres randomized patients, 8 centres had completed the dummy run (DR) for the stereotactic boost part. All participating centres (9) were asked to complete a quality-assurance questionnaire. The DR consisted of treatment planning according to the guidelines of the protocol on 3 different tumour volumes drawn on CT images of a humanized phantom. The SRT technique to be used was evaluated by the questionnaire. Clinical data from patients recruited to the boost arm from 6 participating centres were analysed. Results: There was a full compliance to the protocol requirements for 5 centres. Major and minor deviations in conformality were observed for 2 and 3 centres, respectively. Of the 8 centres which completed the DR, one centre did not comply with the requirements of stereotactic radiotherapy concerning accuracy, dosimetry and planning. Median follow-up and median overall survival were 39.2 and 21.4 months, respectively. Acute and late toxicities of the stereotactic boost were low. One radiation necrosis was seen for a patient who has not received the SRT boost. Three reported serious adverse events were all seizures and probably therapy-related. Conclusions: Overall compliance was good but not ideal from the point of view of this highly precise radiation

  6. Pediatric radiotherapy planning and treatment

    CERN Document Server

    Olch, Arthur J

    2013-01-01

    "This is a very well-written and -organized book covering the planning and delivery aspects unique to pediatric radiotherapy. The author is a respected and well-known medical physicist with extensive pediatric radiotherapy experience. … a very useful book for any clinical physicist treating pediatric cases and seeking contextual and historical perspective. … a great reference for medical physicists who may not see many pediatric cases and can look to this text as a one-stop shop for not only a comprehensive overview, but detailed explanation for specific pediatric disease sites. Overall, it is a great addition to the reference library of any radiation therapy physicist."-Medical Physics, April 2014.

  7. Base-of-tongue carcinoma: treatment results using concomitant boost radiotherapy

    International Nuclear Information System (INIS)

    Mak, Albert C.; Morrison, William H.; Garden, Adam S.; Ang, Kian K.; Goepfert, Helmuth; Peters, Lester J.

    1995-01-01

    Purpose: To evaluate the efficacy of accelerated fractionated radiotherapy using the concomitant boost schedule for patients with squamous cell carcinoma of the base of tongue. Methods and Materials: Between September 1984 and July 1992, 54 patients with squamous carcinoma of the base of tongue were treated at The University of Texas M. D. Anderson Cancer Center using the concomitant boost schedule. The distribution of T and N stages was T1-4, T2-27, T3-22, and T4-1; N0-9, N1-11, N2-24, N3-7, and NX-3. American Joint Committee on Cancer (AJCC) stage groupings were II-6, III-14, and IV-34. Before radiation, nodal excision and neck dissection were done in 5 and 10 patients, respectively; 5 patients had neck dissections after radiotherapy. Standard on and off spinal cord fields were irradiated with 1.8 Gy fractions to 54 Gy given over 6 weeks. The boost was given concomitantly during the large field treatment as a second daily (1.5 Gy) fraction, with an interfraction interval of 4-6 h. The median dose to the primary tumor was 72 Gy (range, 66-74 Gy). The median treatment duration was 42 days (range, 39-48 days). Only three patients had treatment interrupted for more than one scheduled treatment day. Results: The 5-year actuarial overall survival and disease-specific survival rates were 59 and 65%, respectively, with a median follow-up of 41 months. The 5-year actuarial locoregional control rate was 76%. The actuarial local control rates achieved with radiotherapy at 5 years for T1, T2, and T3 primary tumors were 100%, 96%, and 67%, respectively; including surgical salvage, the local control rate of T3 primary tumors was 70%. Six patients had regional failures, which in three patients occurred in conjunction with primary tumor recurrence. Twenty-six patients with regional adenopathy were treated with radiation alone to full dose and had a complete clinical response in the neck; no planned neck dissections were performed in these patients. Only 2 of these 26 patients

  8. Ballistic optimisation with intensity modulation with integration of a concomitant boost for the radiotherapy of glioblastomas; Optimisation de la balistique en modulation d'intensite avec integration d'un boost concomitant pour la radiotherapie des glioblastomes

    Energy Technology Data Exchange (ETDEWEB)

    Supper, C.; Franceries, X. [Universite Paul-Sabatier, 31 - Toulouse (France); Supper, C.; Vieillevigne, L.; Ken, S.; Simon, L.; Rives, M.; Moyal, E.; Delannes, M.; Noel, A.; Laprie, A. [Deparement de radiotherapie, Institut Claudius-Regaud, 31 - Toulouse (France); Franceries, X.; Ken, S.; Laprie, A. [Inserm UMR 825 Imagerie cerebrale et handicapes neurologiques, 31 - Toulouse (France); Noel, A. [Departement de radiotherapie, Centre Alexis-Vautrin, 54 - Nancy (France)

    2010-10-15

    The authors report a study aimed at the optimisation of the ballistics of intensity-modulated conformation radiotherapy (IMRT) treatment with a boost for the preparation of a multi-centric prospective trial financed by a program on glioblastoma treatment. This treatment consists in using the boost technique to obtain an increase of the dose delivered by the IMRT in sites presenting a strong predictive value for relapse. These sites are defined by means of magnetic resonance spectrometric imagery. Conformation indexes, planning target volumes, doses delivered to organs at risk are analysed. The proximity of organs at risk was the main difficulty, but a good dosimetry has been obtained with the use of five coplanar beams. Short communication

  9. Targeted intraoperative radiotherapy (TARGIT) yields very low recurrence rates when given as a boost

    International Nuclear Information System (INIS)

    Vaidya, Jayant S.; Baum, Michael; Tobias, Jeffrey S.; Massarut, Samuele; Wenz, Frederik; Murphy, Olive; Hilaris, Basil; Houghton, Joan B.Sc.; Saunders, Christobel; Corica, Tammy; Roncadin, Mario; Kraus-Tiefenbacher, Uta; Melchaert, Frank; Keshtgar, Mohammed; Sainsbury, Richard; Douek, Michael; Harrison, Elly; Thompson, Alastair; Joseph, David

    2006-01-01

    Purpose: Patients undergoing breast-conserving surgery were offered boost radiotherapy with targeted intraoperative radiotherapy (TARGIT) using the Intrabeam system to test the feasibility, safety, and efficacy of the new approach. Methods and Materials: We treated 302 cancers in 301 unselected patients. This was not a low-risk group. One-third of patients (98/301) were younger than 51 years of age. More than half of the tumors (172, 57%) were between 1 cm and 2 cm, and one-fifth (62, 21%) were >2 cm; 29% (86) had a Grade 3 tumor and, in 29% (87), axillary lymph nodes contained metastasis. After primary surgery, 20 Gy was delivered intraoperatively to the surface of the tumor bed, followed by external-beam radiotherapy (EBRT), but excluding the usual boost. Results: The treatment was well tolerated. The follow-up ranged from 3 to 80 months (164 and 90 patients completed 2 and 3 years follow-up, respectively). Four patients (1.3%) had local recurrence. The Kaplan-Meier estimate of local recurrence is 2.6% (SE = 1.7) at 5 years. This compares favorably with the 4.3% recurrence rate in boosted patients from the EORTC boost study, in which only 8.1% patients were node-positive, as opposed to 29% in our series. Conclusion: Targeted intraoperative radiotherapy combined with EBRT results in a low local recurrence rate. This could be attributed to both accurate targeting and timeliness of the treatment. These data support the need for a randomized trial to test whether the TARGIT boost is superior to conventional external boost, especially in high-risk women

  10. Monte Carlo Treatment Planning for Advanced Radiotherapy

    DEFF Research Database (Denmark)

    Cronholm, Rickard

    This Ph.d. project describes the development of a workflow for Monte Carlo Treatment Planning for clinical radiotherapy plans. The workflow may be utilized to perform an independent dose verification of treatment plans. Modern radiotherapy treatment delivery is often conducted by dynamically...... modulating the intensity of the field during the irradiation. The workflow described has the potential to fully model the dynamic delivery, including gantry rotation during irradiation, of modern radiotherapy. Three corner stones of Monte Carlo Treatment Planning are identified: Building, commissioning...

  11. Urethral dosimetry constraints in 125I permanent prostate brachytherapy used as boost to external radiotherapy

    International Nuclear Information System (INIS)

    Lliso, F.; Perez-Calatayud, J.; Carmona, V.; Guirado, D.; Munoz, M.; Richart, J.; Ballester, F.; Granero, D.; Rodriguez, S.; Tormo, A.; Santos, M.

    2010-01-01

    With 125I monotherapy in permanent brachytherapy implants, the recommendation is to deliver to the urethra less than 150% of the prescribed dose, 145 Gy, that is a limit of 217.5 Gy. However, there are not recommendations in the case of the brachytherapy boost. At our hospitals, permanent brachytherapy implants are used as a 108 Gy boost in intermediate risk patients with prostate carcinoma, which have undergone an external beam radiotherapy course ranging between 45 and 50.4 Gy. The purpose of this work is to present a simple radiobiologically-based analysis performed in order to obtain the urethral dose limit in permanent prostate brachytherapy boost. The linear-quadratic model has been used to determine the biologically effective dose, analysing the results for different dose/fraction, t1/2 and a/b values. Assuming 46 Gy delivered by external beam radiotherapy, it is found that a limit value of 145 Gy, corresponding to the isodose level of 135% of the prescribed dose, is adequate. The results for a ten patients sample are shown in order to illustrate the values that are obtained in clinical practice. In conclusion, we present the method employed to find the urethral dose limit in the case of the combination of external beam radiotherapy and permanent 125I seeds brachytherapy boost implants (Author).

  12. Targeted intraoperative radiotherapy tumour bed boost during breast-conserving surgery after neoadjuvant chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolberg, Hans-Christian; Akpolat-Basci, Leyla; Stephanou, Miltiades [Marienhospital Bottrop gGmbH, Department of Gynecology and Obstetrics, Bottrop (Germany); Loevey, Gyoergy [BORAD, Bottrop (Germany); Fasching, Peter A. [University of Erlangen, Erlangen (Germany); Untch, Michael [Helios Klinikum Berlin-Buch, Berlin (Germany); Liedtke, Cornelia [University Hospital Schleswig-Holstein/Campus Luebeck, Luebeck (Germany); Bulsara, Max [University of Notre Dame, Fremantle (Australia); University College, London (United Kingdom); Vaidya, Jayant S. [University College, London (United Kingdom)

    2017-01-15

    The use of targeted intraoperative radiotherapy (TARGIT-IORT) as a tumour bed boost during breast-conserving surgery (BCS) for breast cancer has been reported since 1998. We present its use in patients undergoing breast conservation following neoadjuvant therapy (NACT). In this retrospective study involving 116 patients after NACT we compared outcomes of 61 patients who received a tumour bed boost with IORT during lumpectomy versus 55 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence-free survival (LRFS), disease-free survival (DFS), distant disease-free survival (DDFS), breast cancer mortality (BCM), non-breast cancer mortality (NBCM) and overall mortality (OS) were compared. Median follow up was 49 months. The differences in LRFS, DFS and BCM were not statistically significant. The 5-year Kaplan-Meier estimate of OS was significantly better by 15% with IORT: IORT 2 events (96.7%, 95%CI 87.5-99.2), EBRT 9 events (81.7%, 95%CI 67.6-90.1), hazard ratio (HR) 0.19 (0.04-0.87), log rank p = 0.016, mainly due to a reduction of 10.1% in NBCM: IORT 100%, EBRT 89.9% (77.3-95.7), HR (not calculable), log rank p = 0.015. The DDFS was as follows: IORT 3 events (95.1%, 85.5-98.4), EBRT 12 events (69.0%, 49.1-82.4), HR 0.23 (0.06-0.80), log rank p = 0.012. IORT during lumpectomy after neoadjuvant chemotherapy as a tumour bed boost appears to give results that are not worse than external beam radiotherapy boost. These data give further support to the inclusion of such patients in the TARGIT-B (boost) randomised trial that is testing whether IORT boost is superior to EBRT boost. (orig.) [German] Die intraoperative Radiotherapie (TARGIT-IORT) als vorgezogener Boost im Rahmen der brusterhaltenden Therapie (BET) ist seit 1998 Gegenstand der wissenschaftlichen Diskussion. Wir praesentieren Daten zum Einsatz der IORT bei der BET nach neoadjuvanter Therapie (NACT). In diese retrospektive Analyse

  13. Intensity-modulated radiotherapy as the boost or salvage treatment of nasopharyngeal carcinoma: The appropriate parameters in the inverse planning and the effect of patient's anatomic factors on the planning results

    International Nuclear Information System (INIS)

    Hsiung, C.-Y.; Hunt, Margie A.; Yorke, Ellen D.; Chui, C.-S.; Hu, Jason; Xiong, J.-P.; Ling, Clifton C.; Lo, S.-K.; Wang, C.-J.; Huang, E.-Y.; Amols, Howard I.

    2005-01-01

    The current study demonstrates that the large increase in normal tissue penalty often degrades target dose uniformity without a concomitant large improvement in normal tissue dose, especially in anatomically unfavorable patients. The excessively large normal tissue penalties do not improve treatment plans for patients having unfavorable geometry

  14. Concepts of radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Mackie, R.T.

    2000-01-01

    Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron emission tomographic (PET) imaging is beginning to be used to determine tumor proliferation and the presence of distant disease. It is likely that accurate RTP in conjunction with CT simulators will eliminate traditional treatment simulators in the future. Traditionally, patient dose calculation algorithms have been based on correcting measured dose in water phantoms to take into account beam modifiers, patient surface contours and internal tissue inhomogeneities. Recently, model-based algorithms have been computing the dose directly in the patient representation using the CT to obtain a voxel-by-voxel density map. The convolution/superposition method, which uses a Monte Carlo-derived transport kernel, is the current state-of-the-art algorithm for dose computation. Soon direct Monte Carlo simulation will be used in model-based dose computation. Model-based dose computations enable a simpler monitor unit calculation formulation. The other major breakthrough in RTP is computer-based optimization. The goals of the treatment are specified as

  15. Intraoperative Boost Radiotherapy during Targeted Oncoplastic Breast Surgery: Overview and Single Center Experiences

    Directory of Open Access Journals (Sweden)

    Wolfram Malter

    2014-01-01

    Full Text Available Breast-conserving surgery followed by whole-breast irradiation is the standard local therapy for early breast cancer. The international discussion of reduced importance of wider tumor-free resection margins than “tumor not touching ink” leads to the development of five principles in targeted oncoplastic breast surgery. IORT improves local recurrence risk and diminishes toxicity since there is less irradiation of healthy tissue. Intraoperative radiotherapy (IORT can be delivered in two settings: an IORT boost followed by a conventional regimen of external beam radiotherapy or a single IORT dose. The data from TARGIT-A and ELIOT reinforce the conviction that intraoperative radiotherapy during breast-conserving surgery is a reliable alternative to conventional postoperative fractionated irradiation, but only in a carefully selected population at low risk of local recurrence. We describe our experiences with IORT boost (50 kV energy X-rays; 20 Gy in combination with targeted oncoplastic breast surgery in a routine clinical setting. Our experiences demonstrate the applicability and reliability of combining IORT boost with targeted oncoplastic breast surgery in breast-conserving therapy of early breast cancer.

  16. Fractionated stereotactic radiotherapy as a boost treatment for tumors in the head and neck region

    International Nuclear Information System (INIS)

    Uno, Takashi; Isobe, Kouichi; Ueno, Naoyuki; Ito, Hisao; Fukuda, Ataru; Sudo, Satoshi; Shirotori, Hiroaki; Kitahara, Isao; Fukushima, Takanori

    2010-01-01

    The objective of this retrospective study was to report initial results of CyberKnife stereotactic radiotherapy (SRT) boost for tumors in the head and neck area. Between March 2008 and August 2009, 10 patients were treated with SRT boost using CyberKnife system due mainly to unfavorable condition such as tumors in close proximity to serial organs or former radiotherapy fields. Treatment sites were the external auditory canal in two, the nasopharynx in one, the oropharynx in three, the nasal cavity in one, the maxillary sinus in two, and the oligometastatic cervical lymph node in one. All patients underwent preceding conventional radiotherapy of 40 to 60 Gy. Dose and fractionation scheme of the Cyberknife SRT boost was individualized, and prescribed dose ranged from 9 Gy to 16 Gy in 3 to 4 fractions. Among four patients for whom dose to the optic pathway was concerned, the maximum dose was only about 3 Gy for three patients whereas 9.6 Gy in the remaining one patient. The maximum dose for the mandible in one of three patients with oropharyngeal cancer was 19.7 Gy, whereas majority of the bone can be spared by using non-isocentric conformal beams. For a patient with nasopharyngeal cancer, the highest dose in the brain stem was 15 Gy. However, majority of the brain stem received less than 40% of the maximum dose. Although a small volume high dose area within the normal structure could be observed in several patients, results of the present study showed potential benefits of the CyberKnife SRT boost. (author)

  17. Effective local control of vertebral metastases by simultaneous integrated boost radiotherapy. Preliminary results

    International Nuclear Information System (INIS)

    Lubgan, Dorota; Ziegaus, Anke; Semrau, Sabine; Lambrecht, Ulrike; Lettmaier, Sebastian; Fietkau, Rainer

    2015-01-01

    The primary endpoint was to improve local tumour control of patients with metastatic spinal tumours by stereotactic body radiotherapy (SBRT) and dose escalation by simultaneous, integrated boost (PTV-boost). We used a whole vertebral body (PTV-elective) contouring approach. Secondary endpoints were severity of acute and chronic adverse effects and overall survival. In all, 33 patients with metastases of the vertebral column were treated at Erlangen University Hospital. SBRT was given in 12 or 10 fractions. The metastatic lesion (PTV-boost) received 3.6 Gy (range 3.0-4.51 Gy) per fraction for a total of 42.0 Gy (24.36-48.0 Gy) and the whole vertebra (PTV-elective) received 2.85 Gy (range 1.8-3.6 Gy) per fraction for a total of 32.39 Gy (range 21.60-38.0 Gy). Patients were followed up every 3 months. Local control rate of all patients was 93 % at 12 and 24 months. The overall survival rate was 54 % at 12 months, 38 % at 24 months and 18 % at 36 months. No radiation myelopathy occurred. The most frequently observed adverse events in 3 cases was oesophagitis grade 2. SBRT with simultaneous, integrated boost was associated with excellent local control of 93 % after 24 months. This result shows the possibility of delivering escalated doses to the target while still keeping the incidence of side effects low. This study forms the basis for a future randomised controlled trial comparing conventional radiotherapy (10 fractions of 3 Gy) with hypofractionated dose intensified SBRT (12 fractions of 3 Gy + integrated boost 12 fractions of 4 Gy) for improvement of local tumour control and pain. (orig.) [de

  18. Identifying the dominant prostate cancer focal lesion using image analysis and planning of a simultaneous integrated stereotactic boost.

    Science.gov (United States)

    Feng, Yang; Welsh, Daniel; McDonald, Kim; Carruthers, Linda; Cheng, Kun; Montgomery, Dean; Lawrence, Jessica; Argyle, David J; McLaughlin, Stephen; McLaren, Duncan B; Nailon, William H

    2015-01-01

    Prostate cancer is now the only solid organ cancer in which therapy is commonly applied to the whole gland. One of the main challenges in adopting focal boost or true focal therapy is in the accurate mapping of cancer foci defined on magnetic resonance (MR) images onto the computerised tomography (CT) images used for radiotherapy planning. Prostate cancer patients (n = 14) previously treated at the Edinburgh Cancer Centre (ECC) were selected for this study. All patients underwent MR scanning for the purpose of diagnosis and staging. Patients received three months of androgen deprivation hormone therapy followed by a radiotherapy planning CT scan. The dominant focal prostate lesions were identified on MR scans by a radiologist and a novel image analysis approach was used to map the location of the dominant focal lesion from MR to CT. An offline planning study was undertaken on suitable patients (n = 7) to investigate boosting of the radiation dose to the tumour using a stereotactic ablative body radiotherapy (SABR) technique. The non-rigid registration algorithm showed clinically acceptable estimates of the location of the dominant focal disease on all CT image data of patients suitable for a boost treatment. Standard rigid registration was found to produce unacceptable estimates of the dominant focal lesion on CT. A SABR boost dose of 47.5 Gy was delivered to the dominant focal lesion of all patients whilst meeting all dose-volume histogram (DVH) constraints. Normal tissue complication probability (NTCP) for the rectum decreased from 1.28% to 0.73% with this method. These preliminary results demonstrate the potential of this image analysis method for reliably mapping dominant focal disease within the prostate from MR images onto planning CT images. Significant dose escalation using a simultaneous integrated SABR boost was achieved in all patients.

  19. The Early Result of Whole Pelvic Radiotherapy and Stereotactic Body Radiotherapy Boost for High Risk Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Yu-Wei eLin

    2014-10-01

    Full Text Available PurposeThe rationale for hypofractionated radiotherapy in the treatment of prostate cancer is based on the modern understanding of radiobiology and advances in stereotactic body radiotherapy (SBRT techniques. Whole-pelvis irradiation combined with SBRT boost for high-risk prostate cancer might escalate biologically effective dose without increasing toxicity. Here, we report our 4-year results of SBRT boost for high-risk localized prostate cancer.Methods and MaterialsFrom October 2009 to August 2012, 41 patients of newly diagnosed, high-risk or very high-risk (NCCN definition localized prostate cancer patients were treated with whole-pelvis irradiation and SBRT boost. The whole pelvis dose was 45Gy (25 fractions of 1.8Gy. The SBRT boost dose was 21 Gy (three fractions of 7 Gy. Ninety percent of these patients received hormone therapy. The toxicities of gastrointestinal (GI and genitourinary (GU tracts were scored by Common Toxicity Criteria Adverse Effect (CTCAE v3.0. Biochemical failure was defined by Phoenix definition.ResultsMedian follow-up was 42 months. Mean PSA before treatment was 44.18 ng/ml. Mean PSA level at 3, 6, 12, 18, and 24 months was 0.94, 0.44, 0.13, 0.12, and 0.05 ng/ml, respectively. The estimated 4-year biochemical failure-free survival was 91.9%. Three biochemical failures were observed. GI and GU tract toxicities were minimal. No grade 3 acute GU or GI toxicity was noted. During radiation therapy, 27% of the patient had grade 2 acute GU toxicity and 12% had grade 2 acute GI toxicity. At 3 months, most toxicity scores had returned to baseline. At the last follow up, there was no grade 3 late GU or GI toxicity.ConclusionsWhole-pelvis irradiation combined with SBRT boost for high-risk localized prostate cancer is feasible with minimal toxicity and encouraging biochemical failure-free survival. Continued accrual and follow-up would be necessary to confirm the biochemical control rate and the toxicity profiles.

  20. Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique.

    Science.gov (United States)

    Borghetti, Paolo; Pedretti, Sara; Spiazzi, Luigi; Avitabile, Rossella; Urpis, Mauro; Foscarini, Federica; Tesini, Giulia; Trevisan, Francesca; Ghirardelli, Paolo; Pandini, Sara Angela; Triggiani, Luca; Magrini, Stefano Maria; Buglione, Michela

    2016-04-19

    To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients. Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively. For each patient, 4 "treatment plans" (VMAT SRS and SIB, helical IMRT SRS and SIB) were calculated and accepted if PTV boost was included in 95 % isodose and dose constraints of the main organs at risk were respected without major deviations. Homogeneity Index (HI), Conformal Index (CI) and Conformal Number (CN) were considered to compare the different plans. Moreover, time of treatment delivery was calculated and considered in the analysis. Volume of brain metastasis ranged between 1.43 and 51.01 cc (mean 12.89 ± 6.37 ml) and 3 patients had double lesions. V95% resulted over 95 % in the average for each kind of technique, but the "target coverage" was inadequate for VMAT planning with two sites. The HI resulted close to the ideal value of zero in all cases; VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS showed mean CI of 2.15, 2.10, 2.44 and 1.66, respectively (optimal range: 1.5-2.0). Helical IMRT-SRS was related to the best and reliable finding of CN (0.66). The mean of treatment time was 210 s, 467 s, 440 s, 1598 s, respectively, for VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS. This dosimetric comparison show that helical IMRT obtain better target coverage and respect of CI and CN; VMAT could be acceptable in solitary metastasis. SIB modality can be considered as a good choice for clinical and logistic compliance; literature's preliminary data are confirming also a

  1. Hypofractionated Concomitant Intensity-Modulated Radiotherapy Boost for High-Risk Prostate Cancer: Late Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Quon, Harvey [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Cheung, Patrick C.F., E-mail: patrick.cheung@sunnybrook.ca [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Loblaw, D. Andrew; Morton, Gerard; Pang, Geordi; Szumacher, Ewa; Danjoux, Cyril [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Choo, Richard [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Thomas, Gillian [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); Kiss, Alex; Mamedov, Alexandre; Deabreu, Andrea [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON (Canada)

    2012-02-01

    Purpose: To report the acute and late toxicities of patients with high-risk localized prostate cancer treated using a concomitant hypofractionated, intensity-modulated radiotherapy boost combined with long-term androgen deprivation therapy. Methods and Materials: A prospective Phase I-II study of patients with any of the following: clinical Stage T3 disease, prostate-specific antigen level {>=}20 ng/mL, or Gleason score 8-10. A dose of 45 Gy (1.8 Gy/fraction) was delivered to the pelvic lymph nodes with a concomitant 22.5 Gy prostate intensity-modulated radiotherapy boost, to a total of 67.5 Gy (2.7 Gy/fraction) in 25 fractions within 5 weeks. Image guidance was performed using three gold seed fiducials. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, and Radiation Therapy Oncology Group late morbidity scores were used to assess the acute and late toxicities, respectively. Biochemical failure was determined using the Phoenix definition. Results: A total of 97 patients were treated and followed up for a median of 39 months, with 88% having a minimum of 24 months of follow-up. The maximal toxicity scores were recorded. The grade of acute gastrointestinal toxicity was Grade 0 in 4%, 1 in 59%, and 2 in 37%. The grade of acute urinary toxicity was Grade 0 in 8%, 1 in 50%, 2 in 39%, and 3 in 4%. The grade of late gastrointestinal toxicity was Grade 0 in 54%, 1 in 40%, and 2 in 7%. No Grade 3 or greater late gastrointestinal toxicities developed. The grade of late urinary toxicity was Grade 0 in 82%, 1 in 9%, 2 in 5%, 3 in 3%, and 4 in 1% (1 patient). All severe toxicities (Grade 3 or greater) had resolved at the last follow-up visit. The 4-year biochemical disease-free survival rate was 90.5%. Conclusions: A hypofractionated intensity-modulated radiotherapy boost delivering 67.5 Gy in 25 fractions within 5 weeks combined with pelvic nodal radiotherapy and long-term androgen deprivation therapy was well tolerated, with low rates

  2. IMRT with Stereotactic Body Radiotherapy Boost for High Risk Malignant Salivary Gland Malignancies : A Case Series

    Directory of Open Access Journals (Sweden)

    Sana D Karam

    2014-10-01

    Full Text Available Patients with high risk salivary gland malignancies are at increased risk of local failure. We present our institutional experience with dose escalation using hypofractionated Stereotactic Body Radiotherapy (SBRT in a subset of this rare disease. Over the course of 9 years, 10 patients presenting with skull base invasion, gross disease with one or more adverse features, or those treated with adjuvant radiation with three or more pathologic features were treated with intensity modulated radiation therapy followed by hypofractionated SBRT boost. Patients presented with variable tumor histologies, and in all but one, the tumors were classified as poorly differentiated high grade. Four patients had gross disease, 3 had gross residual disease, 3 had skull base invasion, and 2 patients had rapidly recurrent disease (≤ 6 months that had been previously treated with surgical resection. The median Stereotactic Radiosurgery boost dose was 17.5 Gy (range 10-30 Gy given in a median of 5 fractions (range 3-6 fractions for a total median cumulative dose of 81.2 Gy (range 73.2-95.6 Gy. The majority of the patients received platinum based concurrent chemotherapy with their radiation. At a median follow-up of 32 months (range 12-120 for all patients and 43 months for surviving patients (range 12-120, actuarial 3-year locoregional control, distant control, progression free survival, and overall survival were 88%, 81%, 68%, and 79%, respectively. Only one patient failed locally and two failed distantly. Serious late toxicity included graft ulceration in 1 patient and osteoradionecrosis in another patient, both of which underwent surgical reconstruction. Six patients developed fibrosis. In a subset of patients with salivary gland malignancies with skull base invasion, gross disease, or those treated adjuvantly with three or more adverse pathologic features, hypofractionated SBRT boost to Intensity Modulated Radiotherapy yields good local control rates and

  3. Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique

    International Nuclear Information System (INIS)

    Borghetti, Paolo; Pedretti, Sara; Spiazzi, Luigi; Avitabile, Rossella; Urpis, Mauro; Foscarini, Federica; Tesini, Giulia; Trevisan, Francesca; Ghirardelli, Paolo; Pandini, Sara Angela; Triggiani, Luca; Magrini, Stefano Maria; Buglione, Michela

    2016-01-01

    To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients. Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively. For each patient, 4 “treatment plans” (VMAT SRS and SIB, helical IMRT SRS and SIB) were calculated and accepted if PTV boost was included in 95 % isodose and dose constraints of the main organs at risk were respected without major deviations. Homogeneity Index (HI), Conformal Index (CI) and Conformal Number (CN) were considered to compare the different plans. Moreover, time of treatment delivery was calculated and considered in the analysis. Volume of brain metastasis ranged between 1.43 and 51.01 cc (mean 12.89 ± 6.37 ml) and 3 patients had double lesions. V95% resulted over 95 % in the average for each kind of technique, but the “target coverage” was inadequate for VMAT planning with two sites. The HI resulted close to the ideal value of zero in all cases; VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS showed mean CI of 2.15, 2.10, 2.44 and 1.66, respectively (optimal range: 1.5–2.0). Helical IMRT-SRS was related to the best and reliable finding of CN (0.66). The mean of treatment time was 210 s, 467 s, 440 s, 1598 s, respectively, for VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS. This dosimetric comparison show that helical IMRT obtain better target coverage and respect of CI and CN; VMAT could be acceptable in solitary metastasis. SIB modality can be considered as a good choice for clinical and logistic compliance; literature’s preliminary data are confirming

  4. IMRT plan verification in radiotherapy

    International Nuclear Information System (INIS)

    Vlk, P.

    2006-01-01

    This article describes the procedure for verification of IMRT (Intensity modulated radiation therapy) plan, which is used in the Oncological Institute of St. Elisabeth in Bratislava. It contains basic description of IMRT technology and developing a deployment plan for IMRT planning system CORVUS 6.0, the device Mimic (Multilammelar intensity modulated collimator) and the overall process of verifying the schedule created. The aim of verification is particularly good control of the functions of MIMIC and evaluate the overall reliability of IMRT planning. (author)

  5. Simultaneous integrated vs. sequential boost in VMAT radiotherapy of high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Farzin, Mostafa [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Tehran University of Medical Science, Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran (Iran, Islamic Republic of); Molls, Michael; Astner, Sabrina; Oechsner, Markus [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Rondak, Ina-Christine [Klinikum rechts der Isar, Technische Universitaet Muenchen, Institut fuer Medizinische Statistik und Epidemiologie, Munich (Germany)

    2015-12-15

    In 20 patients with high-grade gliomas, we compared two methods of planning for volumetric-modulated arc therapy (VMAT): simultaneous integrated boost (SIB) vs. sequential boost (SEB). The investigation focused on the analysis of dose distributions in the target volumes and the organs at risk (OARs). After contouring the target volumes [planning target volumes (PTVs) and boost volumes (BVs)] and OARs, SIB planning and SEB planning were performed. The SEB method consisted of two plans: in the first plan the PTV received 50 Gy in 25 fractions with a 2-Gy dose per fraction. In the second plan the BV received 10 Gy in 5 fractions with a dose per fraction of 2 Gy. The doses of both plans were summed up to show the total doses delivered. In the SIB method the PTV received 54 Gy in 30 fractions with a dose per fraction of 1.8 Gy, while the BV received 60 Gy in the same fraction number but with a dose per fraction of 2 Gy. All of the OARs showed higher doses (D{sub max} and D{sub mean}) in the SEB method when compared with the SIB technique. The differences between the two methods were statistically significant in almost all of the OARs. Analysing the total doses of the target volumes we found dose distributions with similar homogeneities and comparable total doses. Our analysis shows that the SIB method offers advantages over the SEB method in terms of sparing OARs. (orig.) [German] Es wurden 2 Arten der Planung fuer die volumetrisch modulierte Rotationsbestrahlung (VMAT) bei 20 Patienten mit hochgradigen Gliomen verglichen: simultan integrierter Boost (SIB) und sequenzieller Boost (SEB). Dazu wurde die Dosisverteilung in den Zielvolumina und den Risikoorganen analysiert. Es wurden Planungsvolumina (PTV), Boostvolumina (BV) und Risikoorgane konturiert sowie SIB- und SEB-Plaene erstellt. Der SEB besteht aus 2 Plaenen. Im ersten Plan erhaelt das PTV 50 Gy in 25 Fraktionen. Im zweiten Plan erhaelt das Boostvolumen 10 Gy in 5 Fraktionen (Einzeldosis jeweils 2 Gy). Die Dosis

  6. SU-E-T-309: Dosimetric Comparison of Simultaneous Integrated Boost Treatment Plan Between Intensity Modulated Radiotherapies (IMRTs), Dual Arc Volumetric Modulated Arc Therapy (DA-VMAT) and Single Arc Volumetric Modulated Arc Therapy (SA-VMAT) for Nasopharyngeal Carcinoma (NPC)

    International Nuclear Information System (INIS)

    Sivakumar, R; Janardhan, N; Bhavani, P; Surendran, J; Saranganathan, B; Ibrahim, S; Jhonson, B; Madhuri, B; Anuradha, C

    2015-01-01

    Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 in 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered

  7. SU-E-T-309: Dosimetric Comparison of Simultaneous Integrated Boost Treatment Plan Between Intensity Modulated Radiotherapies (IMRTs), Dual Arc Volumetric Modulated Arc Therapy (DA-VMAT) and Single Arc Volumetric Modulated Arc Therapy (SA-VMAT) for Nasopharyngeal Carcinoma (NPC)

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, R; Janardhan, N; Bhavani, P; Surendran, J; Saranganathan, B; Ibrahim, S; Jhonson, B; Madhuri, B [Omega Hospitals, Hyderabad, Telangana (India); Anuradha, C [Vit University, Vellore, Tamil Nadu (India)

    2015-06-15

    Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 in 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered

  8. Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma

    International Nuclear Information System (INIS)

    Kagei, K.; Shirato, H.; Suzuki, K.; Isu, T.; Sawamura, Y.; Sakamoto, T.; Fukuda, S.; Nishioka, T.; Hashimoto, S.; Miyasaka, K.

    1999-01-01

    Purpose: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.Methods and materials: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).< Results: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.Conclusions: Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. SU-G-TeP1-07: Investigation of RapidPlan Based Plan Quality for Breast IMRTSimultaneously Integrated Boost

    International Nuclear Information System (INIS)

    Wang, J; Hu, W; Chen, X; Wu, Z

    2016-01-01

    Purpose: The aim of this study is to investigate the feasibility of using RapidPlan for breast cancer radiotherapy and to evaluate its performance for planners with different planning experiences. Methods: A training database was collected with 80 expert plan datasets from patients previously received left breast conserving surgery and IMRT-simultaneously integrated boost radiotherapy. The models were created on the RapidPlan. Five patients from the training database and 5 external patients were used for internal and external validation, respectively. Three planners with different planning experiences (beginner, junior, senior) designed manual and RapidPlan based plans for additional ten patients. The plan qualities were compared with manual and RapidPlan based ones. Results: For the internal and external validations, there were no significant dose differences on target coverage for plans from RapidPlan and manual. Also, no difference was found in the mean doses to contralateral breast and lung. The RapidPlan improved the heart (V5, V10, V20, V30, and mead dose) and ipsilateral lung (V5, V10, V20, V30, and mean dose) sparing for the beginner and junior planners. Compare to the plans from senior planner, 6 out of 16 clinically checked parameters were improved in RapidPlan, and the left parameters were similar. Conclusion: It is feasible to generate clinical acceptable plans using RapidPlan for breast cancer radiotherapy. The RapidPlan helps to systematically improve the quality of IMRT plans against the benchmark of clinically accepted plans. The RapidPlan shows promise for homogenizing plan quality by transferring planning expertise from more experienced to less experienced planners.

  10. Radiotherapy treatment planning linear-quadratic radiobiology

    CERN Document Server

    Chapman, J Donald

    2015-01-01

    Understand Quantitative Radiobiology from a Radiation Biophysics PerspectiveIn the field of radiobiology, the linear-quadratic (LQ) equation has become the standard for defining radiation-induced cell killing. Radiotherapy Treatment Planning: Linear-Quadratic Radiobiology describes tumor cell inactivation from a radiation physics perspective and offers appropriate LQ parameters for modeling tumor and normal tissue responses.Explore the Latest Cell Killing Numbers for Defining Iso-Effective Cancer TreatmentsThe book compil

  11. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    Science.gov (United States)

    Johansson, Silvia; Åström, Lennart; Sandin, Fredrik; Isacsson, Ulf; Montelius, Anders; Turesson, Ingela

    2012-01-01

    Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU) and gastrointestinal (GI) toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity. PMID:22848840

  12. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Silvia Johansson

    2012-01-01

    Full Text Available Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT. The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU and gastrointestinal (GI toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity.

  13. In vivo dosimetry and acute toxicity in breast cancer patients undergoing intraoperative radiotherapy as boost

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jason Joon Bock; Choi, Jin Hyun; Lee, Ik Jae; Park, Kwang Woo; Kim, Kang Pyo; Kim, Jun Won [Dept. of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Ahn, Sung Gwe; Jeong, Joon [Dept. of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2017-06-15

    To report the results of a correlation analysis of skin dose assessed by in vivo dosimetry and the incidence of acute toxicity. This is a phase 2 trial evaluating the feasibility of intraoperative radiotherapy (IORT) as a boost for breast cancer patients. Eligible patients were treated with IORT of 20 Gy followed by whole breast irradiation (WBI) of 46 Gy. A total of 55 patients with a minimum follow-up of 1 month after WBI were evaluated. Optically stimulated luminescence dosimeter (OSLD) detected radiation dose delivered to the skin during IORT. Acute toxicity was recorded according to the Common Terminology Criteria for Adverse Events v4.0. Clinical parameters were correlated with seroma formation and maximum skin dose. Median follow-up after IORT was 25.9 weeks (range, 12.7 to 50.3 weeks). Prior to WBI, only one patient developed acute toxicity. Following WBI, 30 patients experienced grade 1 skin toxicity and three patients had grade 2 skin toxicity. Skin dose during IORT exceeded 5 Gy in two patients: with grade 2 complications around the surgical scar in one patient who received 8.42 Gy. Breast volume on preoperative images (p = 0.001), ratio of applicator diameter and breast volume (p = 0.002), and distance between skin and tumor (p = 0.003) showed significant correlations with maximum skin dose. IORT as a boost was well-tolerated among Korean women without severe acute complication. In vivo dosimetry with OSLD can help ensure safe delivery of IORT as a boost.

  14. Accelerated superfractionated radiotherapy with concomitant boost for locally advanced head-and-neck squamous cell carcinomas

    International Nuclear Information System (INIS)

    Morris, Monica M.; Schmidt-Ullrich, Rupert K.; DiNardo, L.; Manning, Matthew A.; Silverman, L.; Clay, L.; Johnson, Christopher R.; Amir, Cyrus

    2002-01-01

    Purpose: A growing body of evidence supports the efficacy of accelerated superfractionated radiotherapy with concomitant boost for advanced head-and-neck carcinomas. This study represents a single-institution experience, performed to identify the factors influencing tumor control, survival, and toxicity. Methods and Materials: Between 1988 and 1999, 133 patients with primary squamous cell head-and-neck carcinoma underwent accelerated superfractionated radiotherapy using a concomitant boost. The concomitant boost in this regimen was delivered using reduced fields delivered 3 times weekly in a twice-daily schedule during the final phase. The total radiation dose ranged from 64.8 Gy to 76.5 Gy (mean 71.1). Patients were evaluated in follow-up for local control and late toxicity. Multivariate analysis of treatment and patient parameters was performed to evaluate their influence on toxicity, local control, and overall survival. Results: With a mean follow-up of 37 months, the actuarial overall survival rate for the entire group at 5 years was 24% and the local control rate was 57%. The tumor volume was the most significant predictor of local control, such that each 1-cm 3 increase in volume was associated with a 1% decrease in local control. For patients with tumor volumes ≤30 cm 3 vs. >30 cm 3 , the 5-year disease-specific survival rate was 52% and 27% (p = 0.004) and locoregional control rate was 76% and 26% (p<0.001), respectively. Seventy-six patients with a minimum of 12 months and median of 39 months toxicity follow-up were studied for late effects. None of these patients experienced Grade 4 or 5 toxicity. The actuarial rate of significant toxicity (Grade III or greater) was 32% at 5 years. Of the toxicities observed, xerostomia (19%) was the most common. Multivariate analysis revealed N stage and dose as independent predictors of Grade 3 effects. Conclusion: The locoregional control and survival for patients in this institutional experience compare favorably to

  15. Planned combined radiotherapy and surgery

    International Nuclear Information System (INIS)

    Silverman, C.L.; Marks, J.E.

    1987-01-01

    Though the planned combined use of surgery and radiation has been shown to be beneficial for other tumors, the authors feel that the present evidence is far from persuasive in demonstrating a definite superiority of combined therapy over surgery or radiation alone for advanced laryngeal tumors. The actuarial or disease-free survival rates for patients treated with combined therapy have not been significantly increased over those obtained with a single modality in any randomized, well-controlled study, although the trend is toward improved local regional control. Many of the retrospective studies are probably flawed by selection bias; the patients selected for combined treatment generally have more advanced cancers and represent a worse prognostic group. It is clear from this review that the positive value of irradiation for advanced transglottic and supraglottic tumors needs to be documented by a controlled study that compares surgery alone with salvage radiation at time of recurrence to surgery plus adjuvant radiation. The authors feel that such a study is needed to put to rest the present controversy before they can advocate a course of treatment that is expensive, time-consuming, and difficult for the patients to tolerate owing to severe acute side effects and potentially morbid late effects (xerostomia, necrosis) that can greatly lessen the quality of life for these patients

  16. Accuracy requirements in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Buzdar, S. A.; Afzal, M.; Nazir, A.; Gadhi, M. A.

    2013-01-01

    Radiation therapy attempts to deliver ionizing radiation to the tumour and can improve the survival chances and/or quality of life of patients. There are chances of errors and uncertainties in the entire process of radiotherapy that may affect the accuracy and precision of treatment management and decrease degree of conformation. All expected inaccuracies, like radiation dose determination, volume calculation, complete evaluation of the full extent of the tumour, biological behaviour of specific tumour types, organ motion during radiotherapy, imaging, biological/molecular uncertainties, sub-clinical diseases, microscopic spread of the disease, uncertainty in normal tissue responses and radiation morbidity need sound appreciation. Conformity can be increased by reduction of such inaccuracies. With the yearly increase in computing speed and advancement in other technologies the future will provide the opportunity to optimize a greater number of variables and reduce the errors in the treatment planning process. In multi-disciplined task of radiotherapy, efforts are needed to overcome the errors and uncertainty, not only by the physicists but also by radiologists, pathologists and oncologists to reduce molecular and biological uncertainties. The radiation therapy physics is advancing towards an optimal goal that is definitely to improve accuracy where necessary and to reduce uncertainty where possible. (author)

  17. Accelerated radiotherapy with delayed concomitant boost in locally advanced squamous cell carcinoma of the head and neck

    International Nuclear Information System (INIS)

    MacKenzie, Robert; Balogh, Judith; Choo, Richard; Franssen, Edmee

    1999-01-01

    Purpose: To determine the toxicity, maximum tolerated dose (MTD), and clinical effectiveness of a 5-week course of accelerated radiotherapy with delayed concomitant boost in locally advanced squamous cell carcinoma of the head and neck (SCCHN). Methods and Materials: Thirty-five patients with untreated T3T4NM0 or TN2 (> 3 cm) N3M0 SCC of the oral cavity, oropharynx, hypopharynx, or larynx were entered in the study between January 1994 and October 1997. The initial target volume was treated with conventional daily fractions. A small field boost covering gross disease was added as a second daily fraction during the last 2 weeks of the 5-week schedule, using a minimum interfraction interval of 6 h. The study was initiated using 180-cGy fractions to deliver a total dose of 63 Gy over 33-35 days. A classical dose escalation strategy was planned to increase the delivered dose in steps using minimum cohorts of three patients, up to a maximum of 70 Gy in 200-cGy fractions. Results: In the dose escalation study, 4 patients were entered at level 1 (63 Gy), 9 at level 2 (65 Gy), and 8 at level 3 (67 Gy). One patient was withdrawn at level 2 because of unstable angina, and 1 at level 3 because of uncontrolled diabetes. One patient at level 3 failed to complete treatment because of radiation toxicity. RTOG Grade 3 mucositis, dermatitis, or pharyngitis was documented in 1 (25%), 5 (63%), and 7 (100%) evaluable patients at levels 1, 2, and 3, respectively. Grade 4 reactions were documented in 1 patient at each level. One patient at level 3 died 5 weeks post-treatment of unknown causes. Two additional patients at level 3 died of progressive disease and RT toxicity. Sixty-five Gy (level 2) was chosen as the MTD. In the MTD study, 14 additional patients were entered at level 2, providing a total of 22 evaluable patients with a median follow-up of 21 months (range 12-41 months). Grade 3 mucositis, dermatitis, or pharyngitis were documented in 11 (50%), 8 (36%), and 6 (27%) patients

  18. Sequentially delivered boost plans are superior to simultaneously delivered plans in head and neck cancer when the boost volume is located further away from the parotid glands

    NARCIS (Netherlands)

    Lamers-Kuijper, Emmy; Heemsbergen, Wilma; van Mourik, Anke; Rasch, Coen

    2011-01-01

    To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare the salivary glands. We evaluated 50 recently treated head and neck cancer patients. Apart from the clinical plan

  19. Failure of a 3D conformal boost to improve radiotherapy for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Wolden, Suzanne L.; Zelefsky, Michael J.; Hunt, Margie A.; Rosenzweig, Kenneth E.; Chong, Lanceford M.; Kraus, Dennis H.; Pfister, David G.; Leibel, Steven A.

    2001-01-01

    Purpose: To determine whether the use of 3-dimensional (3D) boost for patients with nasopharynx cancer improves local control and reduces the risk of long-term complications. Methods and Materials: From 1988 to 1998, 68 patients with nasopharynx cancer received conventional external beam therapy followed by a 3D boost. Disease characteristics of treated patients were as follows: WHO I histology 7%, WHO II 62%, WHO III 31%, clinical AJCC stage T1-2 45%, T3-4 55%, N0-1 63%, N2-3 37%, M0 100%. The median radiation dose was 70 Gy (68-75.6 Gy). Thirty-five patients (52%) received cisplatin-based chemotherapy. The median follow-up of surviving patients was 42 months (12-118 months). Results: Five-year actuarial local control was 77%, regional control was 97%, progression-free survival was 56%, and overall survival was 58%. Stage was the only identifiable prognostic factor: 5-year progression-free survival was 65% for Stages I-III vs. 40% for Stage IV (p 0.01). The incidence of Grade 3-4 complications was 25% and included hearing loss, trismus, dysphagia, chronic sinusitis, and cranial neuropathy. These results are comparable to outcomes reported with conventional radiation techniques for similarly staged patients. Conclusion: The lack of a major benefit with the 3D boost may be related to the fact that CT planning was only used for a fraction of the total dose. We are now using intensity modulated radiation therapy to deliver the entire course of radiation. Intensity modulated radiation therapy achieves better conformal distributions than conventional 3D planning, allowing dose escalation and increased normal tissue sparing

  20. Simultaneous Integrated Boost Using Intensity-Modulated Radiotherapy Compared With Conventional Radiotherapy in Patients Treated With Concurrent Carboplatin and 5-Fluorouracil for Locally Advanced Oropharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen, David H.A.; Fortin, Bernard [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Despres, Philippe [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Khaouam, Nader [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Donath, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Soulieres, Denis [Department of Medical Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen-Tan, Phuc Felix [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada)

    2012-02-01

    Purpose: To compare, in a retrospective study, the toxicity and efficacy of simultaneous integrated boost using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT) in patients treated with concomitant carboplatin and 5-fluorouracil for locally advanced oropharyngeal cancer. Methods and Materials: Between January 2000 and December 2007, 249 patients were treated with definitive chemoradiation. One hundred patients had 70 Gy in 33 fractions using IMRT, and 149 received CRT at 70 Gy in 35 fractions. Overall survival, disease-free survival, and locoregional control were estimated using the Kaplan-Meier method. Results: Median follow-up was 42 months. Three-year actuarial rates for locoregional control, disease-free survival, and overall survival were 95.1% vs. 84.4% (p = 0.005), 85.3% vs. 69.3% (p = 0.001), and 92.1% vs. 75.2% (p < 0.001) for IMRT and CRT, respectively. The benefit of the radiotherapy regimen on outcomes was also observed with a Cox multivariate analysis. Intensity-modulated radiotherapy was associated with less acute dermatitis and less xerostomia at 6, 12, 24, and 36 months. Conclusions: This study suggests that simultaneous integrated boost using IMRT is associated with favorable locoregional control and survival rates with less xerostomia and acute dermatitis than CRT when both are given concurrently with chemotherapy.

  1. Stereotactic body radiotherapy: a promising treatment option for the boost of oropharyngeal cancers not suitable for brachytherapy: a single-institutional experience.

    NARCIS (Netherlands)

    Al-Mamgani, A.; Tans, L.; Teguh, D.N.; Rooij, P. van; Zwijnenburg, E.M.; Levendag, P.C.

    2012-01-01

    PURPOSE: To prospectively assess the outcome and toxicity of frameless stereotactic body radiotherapy (SBRT) as a treatment option for boosting primary oropharyngeal cancers (OPC) in patients who not suitable for the standard brachytherapy boost (BTB). METHODS AND MATERIALS: Between 2005 and 2010,

  2. Automated radiotherapy treatment plan integrity verification

    International Nuclear Information System (INIS)

    Yang Deshan; Moore, Kevin L.

    2012-01-01

    Purpose: In our clinic, physicists spend from 15 to 60 min to verify the physical and dosimetric integrity of radiotherapy plans before presentation to radiation oncology physicians for approval. The purpose of this study was to design and implement a framework to automate as many elements of this quality control (QC) step as possible. Methods: A comprehensive computer application was developed to carry out a majority of these verification tasks in the Philips PINNACLE treatment planning system (TPS). This QC tool functions based on both PINNACLE scripting elements and PERL sub-routines. The core of this technique is the method of dynamic scripting, which involves a PERL programming module that is flexible and powerful for treatment plan data handling. Run-time plan data are collected, saved into temporary files, and analyzed against standard values and predefined logical rules. The results were summarized in a hypertext markup language (HTML) report that is displayed to the user. Results: This tool has been in clinical use for over a year. The occurrence frequency of technical problems, which would cause delays and suboptimal plans, has been reduced since clinical implementation. Conclusions: In addition to drastically reducing the set of human-driven logical comparisons, this QC tool also accomplished some tasks that are otherwise either quite laborious or impractical for humans to verify, e.g., identifying conflicts amongst IMRT optimization objectives.

  3. Dosimetry audit of radiotherapy treatment planning systems.

    Science.gov (United States)

    Bulski, Wojciech; Chełmiński, Krzysztof; Rostkowska, Joanna

    2015-07-01

    In radiotherapy Treatment Planning Systems (TPS) various calculation algorithms are used. The accuracy of dose calculations has to be verified. Numerous phantom types, detectors and measurement methodologies are proposed to verify the TPS calculations with dosimetric measurements. A heterogeneous slab phantom has been designed within a Coordinated Research Project (CRP) of the IAEA. The heterogeneous phantom was developed in the frame of the IAEA CRP. The phantom consists of frame slabs made with polystyrene and exchangeable inhomogeneity slabs equivalent to bone or lung tissue. Special inserts allow to position thermoluminescent dosimeters (TLD) capsules within the polystyrene slabs below the bone or lung equivalent slabs and also within the lung equivalent material. Additionally, there are inserts that allow to position films or ionisation chamber in the phantom. Ten Polish radiotherapy centres (of 30 in total) were audited during on-site visits. Six different TPSs and five calculation algorithms were examined in the presence of inhomogeneities. Generally, most of the results from TLD were within 5 % tolerance. Differences between doses calculated by TPSs and measured with TLD did not exceed 4 % for bone and polystyrene equivalent materials. Under the lung equivalent material, on the beam axis the differences were lower than 5 %, whereas inside the lung equivalent material, off the beam axis, in some cases they were of around 7 %. The TLD results were confirmed with the ionisation chamber measurements. The comparison results of the calculations and the measurements allow to detect limitations of TPS calculation algorithms. The audits performed with the use of heterogeneous phantom and TLD seem to be an effective tool for detecting the limitations in the TPS performance or beam configuration errors at audited radiotherapy departments. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Role of multimodality imaging in radiotherapy planning

    International Nuclear Information System (INIS)

    Lee, Young K.

    2004-01-01

    Accurate tumor delineation is crucial to achieve successful radiotherapy (RT). While CTs are clinically used to plan 3D-RT, multimodality imaging (MMI) promises to aid accurate delineation of the tumor. This thesis examined delineated MMI volumes and studied their role in RT planning. A prostate modeling study evaluated the dose reductions in conformal and intensity-modulated radiotherapy (CRT and IMRT) due to interfractional gross tumor volume (GTV) motion and variability in delineation. In both CRT and IMRT, a 10 mm margin was adequate to account for interfractional GTV movement. However, 10 mm (CRT) and 5 mm (IMRT) GTV misdelineation produced unacceptable dose distributions. IMRT plans were more affected by delineation errors when compared to CRT plans due to their steep dose gradients. Methods were developed to use MRI only in RT planning. Water and bone electron density values were assigned to the image and a low-distortion MR-sequence was used. MR-delineated prostate volumes were in general smaller than those on CT by 10%. Patient data were separated into those that were affected by organ motion from those that were not. An independent-organ registration technique was developed to relate CT- and MR-delineated volumes that were affected by organ motion between the scans. The dosimetric study showed that unacceptable CRT was planned using planning target volume delineated using CT (PTV CT ) when PTV MR volumes were assumed to be true. However, the dosimetric benefit was small as a 1-2 mm marginal increase on PTV CT would deliver adequate dose to both PTVs and insignificant dose reductions were observed in rectum and bladder when PTV MR plans were compared to PTV CT plans. The dosimetric effect of 123 I-mIBG-SPECT in neuroblastoma CRT and IMRT was studied. Reduction in tumor control probability due to incorrectly delineated neuroblastoma was observed and a new treatment was planned using PTV CT+SPECT with acceptable doses to OARs the organs-at-risk. IMRT

  5. Tumour bed delineation for partial breast/breast boost radiotherapy: What is the optimal number of implanted markers?

    International Nuclear Information System (INIS)

    Kirby, Anna NM.; Jena, Rajesh; Harris, Emma J.; Evans, Phil M.; Crowley, Clare; Gregory, Deborah L.; Coles, Charlotte E.

    2013-01-01

    Purpose: International consensus has not been reached regarding the optimal number of implanted tumour bed (TB) markers for partial breast/breast boost radiotherapy target volume delineation. Four common methods are: insertion of 6 clips (4 radial, 1 deep and 1 superficial), 5 clips (4 radial and 1 deep), 1 clip at the chest wall, and no clips. We compared TB volumes delineated using 6, 5, 1 and 0 clips in women who have undergone wide-local excision (WLE) of breast cancer (BC) with full-thickness closure of the excision cavity, in order to determine the additional margin required for breast boost or partial breast irradiation (PBI) when fewer than 6 clips are used. Methods: Ten patients with invasive ductal BC who had undergone WLE followed by implantation of six fiducial markers (titanium clips) each underwent CT imaging for radiotherapy planning purposes. Retrospective processing of the DICOM image datasets was performed to remove markers and associated imaging artefacts, using an in-house software algorithm. Four observers outlined TB volumes on four different datasets for each case: (1) all markers present (CT 6M ); (2) the superficial marker removed (CT 5M ); (3) all but the chest wall marker removed (CT CW ); (4) all markers removed (CT 0M ). For each observer, the additional margin required around each of TB 0M , TB CW , and TB 5M in order to encompass TB 6M was calculated. The conformity level index (CLI) and differences in centre-of-mass (COM) between observers were quantified for CT 0M , CT CW , CT 5M , CT 6M . Results: The overall median additional margins required to encompass TB 6M were 8 mm (range 0–28 mm) for TB 0M , 5 mm (range 1–13 mm) for TB CW , and 2 mm (range 0–7 mm) for TB 5M . CLI were higher for TB volumes delineated using CT 6M (0.31) CT 5M (0.32) than for CT CW (0.19) and CT 0M (0.15). Conclusions: In women who have undergone WLE of breast cancer with full-thickness closure of the excision cavity and who are proceeding to PBI or

  6. Redistributed versus homogenous radiotherapy dose for head and neck cancer; a treatment planning study

    Directory of Open Access Journals (Sweden)

    Jolien Heukelom

    2017-07-01

    Full Text Available Dose redistribution, where radio-resistant parts of the tumour are boosted while the border of the planning target volume receives a lower dose has the potential to increase local control in advanced head and neck squamous cell carcinoma (HNSCC. In this treatment planning study for 20 patients, standard radiotherapy (RT of 70 Gy, was compared to redistributed RT following the ARTFORCE trial protocol (NCT01504815, i.e., a fluorodeoxyglucose-positron emission tomography (FDG-PET based heterogeneous simultaneous-integrated-boost to a total dose of 64–84 Gy. Redistribution marginally increased the mean ipsilateral ⧹contralateral parotid dose by 1.55⧹0.55 Gy but not dose to other organs at risk.

  7. Local recurrence rates in breast cancer patients treated with intraoperative electron-boost radiotherapy versus postoperative external-beam electron-boost irradiation. A sequential intervention study

    International Nuclear Information System (INIS)

    Reitsamer, R.; Menzel, C.; Peintinger, F.; Kopp, M.; Kogelnik, H.D.; Sedlmayer, F.

    2004-01-01

    Background and purpose: the purpose of this sequential intervention study was to determine the rate of local recurrences and the rate of distant metastases in patients with invasive breast cancer who had been treated with breast-conserving surgery and postoperative radiation therapy to the whole breast either with postoperative electron boost in group 1 or with intraoperative electron boost (IORT) in group 2. Patients and methods: after breast-conserving surgery, 378 women with invasive breast cancer of tumor sizes T1 and T2 received 51-56.1 gy of postoperative radiation therapy to the whole breast in 1.7-gy fractions. 188 of those patients additionally received a postoperative electron boost of 12 gy in group 1 from January 1996 to October 1998. Consecutively, from October 1998 to March 2001, 190 patients received intraoperative electron-boost radiotherapy of 9 gy to the tumor bed in group 2. The groups were comparable with regard to age, menopausal status, tumor size, grading, and nodal status. All statistical tests were two-sided. Results: during a median follow-up period of 55.3 months in group 1 and 25.8 months in group 2, local recurrences were observed in eight of 188 patients (4.3%) in group 1, and no local recurrence was seen in group 2 (p = 0.082). Distant metastases occurred in 15 of the 188 patients (7.9%) in group 1 and in two of the 190 patients (1.1%) in group 2 (p = 0.09). The 4-year actuarial rates of local recurrence were 4.3% (95% confidence interval, 1.8-8.2%) and 0.0% (95% confidence interval, 0.0-1.9%) and the 4-year actuarial rates of distant metastases were 7.9% (95% confidence interval, 4.5-12.8%) and 1.1% (95% confidence interval, 0.1-3.8%). Conclusion: immediate IORT boost yielded excellent local control figures in this prospective investigation and appears to be superior to conventional postoperative boost in a short-term follow-up. (orig.)

  8. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    Directory of Open Access Journals (Sweden)

    Korevaar Erik W

    2008-01-01

    Full Text Available Abstract Background The shift from conventional two-dimensional (2D to three-dimensional (3D-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT-based breast and boost planning target volumes (PTV, absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Methods Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. Results With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. Conclusion The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on

  9. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    International Nuclear Information System (INIS)

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

    2008-01-01

    The shift from conventional two-dimensional (2D) to three-dimensional (3D)-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT)-based breast and boost planning target volumes (PTV), absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on clinical data confirming tumour control probability and normal

  10. Comparison of concomitant boost radiotherapy against concurrent chemoradiation in locally advanced oropharyngeal cancers: A phase III randomised trial

    International Nuclear Information System (INIS)

    Rishi, Anupam; Ghoshal, Sushmita; Verma, Roshan; Oinam, Arun S.; Patil, Vijai M.; Mohinder, Rakesh; Sharma, Suresh C.

    2013-01-01

    Purpose: To test the toxicity and efficacy of concomitant boost radiotherapy alone against concurrent chemoradiation (conventional fractionation) in locally advanced oropharyngeal cancer in our patient population. Methods and materials: In this open-label, randomised trial, 216 patients with histologically proven Stage III–IVA oropharyngeal cancer were randomly assigned between June 2006 and December 2010 to receive either chemoradiation (CRT) to a dose of 66 Gy in 33 fractions over 6.5 weeks with concurrent cisplatin (100 mg/m 2 on days 1, 22 and 43) or accelerated radiotherapy with concomitant boost (CBRT) to a dose of 67.5 Gy in 40 fractions over 5 weeks. The compliance, toxicity and quality of life were investigated. Disease-free survival (DFS) and overall survival (OS) curves were estimated with the Kaplan–Meier method and compared using log rank test. Results: The compliance to radiotherapy was superior in concomitant boost with lesser treatment interruptions (p = 0.004). Expected acute toxicities were significantly higher in CRT, except for grade 3/4 mucositis which was seen more in CBRT arm (39% and 55% in CRT and CBRT, respectively; p = 0.02). Late toxicities like Grade 3 xerostomia were significantly high in CRT arm than CBRT arm (33% versus 18%; p 2 cm had significantly better DFS with CRT (p = 0.05; HR-1.59, 95%CI-0.93–2.7). Conclusion: In selected patients of locally advanced oropharyngeal cancer, concomitant boost offers a better compliance, toxicity profile and quality of life with similar disease control, than chemoradiation

  11. PET/CT Based Dose Planning in Radiotherapy

    DEFF Research Database (Denmark)

    Berthelsen, Anne Kiil; Jakobsen, Annika Loft; Sapru, Wendy

    2011-01-01

    radiotherapy planning with PET/CT prior to the treatment. The PET/CT, including the radiotherapy planning process as well as the radiotherapy process, is outlined in detail. The demanding collaboration between mould technicians, nuclear medicine physicians and technologists, radiologists and radiology......This mini-review describes how to perform PET/CT based radiotherapy dose planning and the advantages and possibilities obtained with the technique for radiation therapy. Our own experience since 2002 is briefly summarized from more than 2,500 patients with various malignant diseases undergoing...... technologists, radiation oncologists, physicists, and dosimetrists is emphasized. We strongly believe that PET/CT based radiotherapy planning will improve the therapeutic output in terms of target definition and non-target avoidance and will play an important role in future therapeutic interventions in many...

  12. Accuracy of dose distribution calculated by radiotherapy planning computer

    International Nuclear Information System (INIS)

    Ito, Shinya

    1982-01-01

    It is important to notify the accuracy of dose distribution prepared by Radiotherapy Planning Computer. The following experiment was performed to compare the results of calculation dose by the MODULEX Radiotherapy Planning Computer and measured values. Under the several different conditions of irradiation by 10 MV X-ray Linear Accelerator. The results were shown that the difference between measured values and calculated values were less than 3% and calculated data by Radiotherapy Planning Computer were accurate enough for routine use. The accuracy of computer calculated data depend so much on calculation system and accuracy of input data that careful management of raw data were needed. (author)

  13. Pilot of the BOOST-A™: An online transition planning program for adolescents with autism.

    Science.gov (United States)

    Hatfield, Megan; Murray, Nina; Ciccarelli, Marina; Falkmer, Torbjörn; Falkmer, Marita

    2017-12-01

    Many adolescents with autism face difficulties with the transition from high school into post-school activities. The Better OutcOmes & Successful Transitions for Autism (BOOST-A™) is an online transition planning program which supports adolescents on the autism spectrum to prepare for leaving school. This study describes the development of the BOOST-A™ and aimed to determine the feasibility and viability of the program. Two pilot studies were conducted. In Pilot A, the BOOST-A™ was trialled by six adolescents on the autism spectrum, their parents, and the professionals who worked with them, to determine its feasibility. In Pilot B, 88 allied health professionals (occupational therapists, speech pathologists, and psychologists) reviewed the BOOST-A™ to determine its viability. Participants rated the BOOST-A™ as a feasible tool for transition planning. The majority of allied health professionals agreed that it was a viable program. Based on participant feedback, the BOOST-A™ was modified to improve usability and feasibility. The BOOST-A™ is a viable and feasible program that has the potential to assist adolescents with autism in preparing for transitioning out of high school. Future research will determine the effectiveness of the BOOST-A™ with adolescents across Australia. © 2017 Occupational Therapy Australia.

  14. Smart (simultaneous modulated accelerated radiation therapy) boost: a new accelerated fractionation schedule for the treatment of head and neck cancer with intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    Butler, E. Brian; Teh, Bin S.; Grant, Walter H.; Uhl, Barry M.; Kuppersmith, Ronald B.; Chiu, J. Kam; Donovan, Donald T.; Woo, Shiao Y.

    1999-01-01

    Purpose: To report the initial experience in the definitive treatment of head and neck carcinomas using SMART (Simultaneous Modulated Accelerated Radiation Therapy) boost technique. Radiation was delivered via IMRT (Intensity Modulated Radiotherapy). The following parameters were evaluated: acute toxicity, initial tumor response, clinical feasibility, dosimetry and cost. Methods and Materials: Between January 1996 and December 1997, 20 patients with primary head and neck carcinomas were treated with SMART boost technique. The treatment fields encompassed two simultaneous targets. The primary target included palpable and visible disease sites. The secondary target included regions at risk for microscopic disease. Daily fractions of 2.4 Gy and 2 Gy were prescribed and delivered to the primary and secondary targets to a total dose of 60 Gy and 50 Gy, respectively. Lower neck nodes were treated with a single conventional anterior portal. This fractionation schedule was completed in 5 weeks with 5 daily fractions weekly. Toxicity was evaluated by RTOG acute toxicity grading criteria, evidence of infection at immobilization screw sites, subjective salivary function, weight loss, and the need for treatment split. Mean follow-up was 15.2 months. Initial tumor response was assessed by clinical and radiographical examinations. Clinical feasibility was evaluated by the criteria: time to treat patient, immobilization, and treatment planning and QA time. In dosimetry, we evaluated the mean doses of both targets and normal tissues and percent targets' volume below goal. To evaluate cost, Medicare allowable charge for SMART boost was compared to those of conventional fractionated and accelerated radiotherapy. Results: Acute toxicity: None of the patients had a screw site infection and all patients healed well after completion of radiotherapy. Sixteen of 20 patients (80%) completed the treatment within 40 days without any split. Sixteen patients (80%) had RTOG Grade 3 mucositis

  15. Comparison of Toxicities Associated with Concomitant Boost and Conventional Fractionated Radiotherapy Regimen in Oral and Oropharyngeal Cancers

    Directory of Open Access Journals (Sweden)

    Abhishek Shrivastava

    2017-10-01

    Full Text Available Introduction: The prevalence of Head and Neck Cancers (HNC is very high in the Indian subcontinent. Radiotherapy is an essential modality in the management of HNC. Aim: The aim of the present study was to compare toxicities of two radiotherapy fractionation regimen (conventional fractionation and concomitant boost technique for the management of HNC. Materials and Methods: A total of 60 patients (n=30 in each arm were assigned to receive either conventional fractionation or concomitant boost radiotherapy. Toxicities were analysed weekly during the treatment, and one and three month after treatment completion. The radiation therapy oncology group acute radiation morbidity scoring system was used to document the severity. Toxicities assessed were mucositis, skin reactions, dysphagia and xerostomia. Statistical analysis was done by the online Graphpad software using Chi-square test. A value of p<0.05 was considered significant. Results: Overall mean age of the patients was 47.35 years (range 23-70 years. There was a male preponderance in both groups (Group A=73.33%, Group B= 76.6%. Most common primary sub site in Group A was tongue (33.3% and in Group B was buccal mucosa (50%. On statistical analysis of toxicity comparison during and post treatment completion, no significant difference in toxicity was found between the two arms in terms of mucositis (p=1, skin reactions (p=0.6404, dysphagia (p=0.7906 and xerostomia (p=0.1066. Conclusion: The concomitant boost technique resulted in no statistically significant difference in toxicity as compared to the conventional fractionation with the added advantage of reduced overall treatment time. This may be a favourable schedule for high volume centers.

  16. Phase II study to assess the efficacy of conventionally fractionated radiotherapy followed by a stereotactic radiosurgery boost in patients with locally advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Koong, Albert C.; Christofferson, Erin; Le, Quynh-Thu; Goodman, Karyn A.; Ho, Anthony; Kuo, Timothy; Ford, James M.; Fisher, George A.; Greco, Ralph; Norton, Jeffrey; Yang, George P.

    2005-01-01

    Purpose: To determine the efficacy of concurrent 5-fluorouracil (5-FU) and intensity-modulated radiotherapy (IMRT) followed by body stereotactic radiosurgery (SRS) in patients with locally advanced pancreatic cancer. Methods and Materials: In this prospective study, all patients (19) had pathologically confirmed adenocarcinoma and were uniformly staged. Our treatment protocol consisted of 45 Gy IMRT with concurrent 5-FU followed by a 25 Gy SRS boost to the primary tumor. Results: Sixteen patients completed the planned therapy. Two patients experienced Grade 3 toxicity (none had more than Grade 3 toxicity). Fifteen of these 16 patients were free from local progression until death. Median overall survival was 33 weeks. Conclusions: Concurrent IMRT and 5-FU followed by SRS in patients with locally advanced pancreatic cancer results in excellent local control, but does not improve overall survival and is associated with more toxicity than SRS, alone

  17. Conformal radiotherapy with intensity modulation and integrated boost in the head and neck cancers: experience of the Curie Institute

    International Nuclear Information System (INIS)

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

    2009-01-01

    The modulated intensity radiotherapy (I.M.R.T.) is used in the treatment of cancers in superior aero digestive tracts to reduce the irradiation of parotids and to reduce the delayed xerostomia. This retrospective study presents the results got on the fourteen first patients according an original technique of I.M.R.T. with integrated boost. It appears that this technique is feasible and allows to reduce the xerostomia rate without modifying the local control rate. To limit the average dose to the parotids under 30 Gy seems reduce the incidence of severe xerostomia. (N.C.)

  18. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

    Directory of Open Access Journals (Sweden)

    Ken Soléakhéna

    2013-01-01

    Full Text Available Abstract Background To integrate 3D MR spectroscopy imaging (MRSI in the treatment planning system (TPS for glioblastoma dose painting to guide simultaneous integrated boost (SIB in intensity-modulated radiation therapy (IMRT. Methods For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT, one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE. Results Fusion assessment was performed for 160 transformations. It resulted in maximum differences p  Conclusions Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies.

  19. Intraoperative radiotherapy electron boost in advanced and recurrent epithelial ovarian carcinoma: a retrospective study

    International Nuclear Information System (INIS)

    Gao, Ying; Liu, Zi; Chen, Xi; Luo, Wei; Zhang, Long; Wang, Juan

    2011-01-01

    Relapses of epithelial ovarian carcinoma (EOC) have a poor prognosis and are almost always fatal. The aim of this study was to evaluate the clinical outcome and toxicity of intraoperative electron beam radiation therapy (IOERT) in advanced and recurrent EOC. Forty-five women with EOC were treated with IOERT. Twenty-five patients had primary disease (PD) without distant metastasis at IOERT, and 20 patients had an isolated local recurrence (ILR) after surgery. All 45 patients in this series underwent optimal cytoreductive (≤ 1 cm) surgery. The whole pelvic (WP) radiotherapy was intraoperatively delivered using 12 Mev electron beam; 43 patients received 18-20 Gy and two patients received 10 Gy. Thirty-three patients received postoperateive intraperitoneal (IP) chemotherapy, while seven patients received intravenous (IV) chemotherapy. Five patients refused concurrent chemotherapy. Overall survival (OS) rates were analyzed using the Kaplan-Meier method. Tumor recurrence and metastasis were observed in 16 patients (35.6%). Of those, 14 patients (31.1%) relapsed and two patients (4.4%) had distant metastasis alone. Eight of 25 (32%) local failures were observed in the PD group, as compared to 6/20 (30%) in the ILR group (P = 0.885). Actuarial local control at five year follow-up was 31/45 (68.9%). Seventeen of the total 45 (37.8%) patients died. Nine of 25 (36%) in the PD group died, as compared to 8 of 20 (40%) in the ILR group. The 5-year OS and disease-free survival (DFS) rates were 28/45 (62.2%) and 25/45 (55.6%), respectively. In the PD group, the 5-year OS and DFS rates were 16/25 (64%) and 14/25 (56%) (P > 0.05, vs. the ILR group at 12/20 and 11/20, respectively). The OS and DFS in the IOERT plus IP group were 25/33 (75.8%) and 23/33 (69.7%), respectively, which were superior to the rates achieved with IOERT plus IV chemotherapy (P < 0.05, 2/7 and 1/7, respectively). The major complication of IOERT was neuropathy. Five (11.1%) patients developed peripheral

  20. SU-G-TeP1-05: Development and Clinical Introduction of Automated Radiotherapy Treatment Planning for Prostate Cancer

    International Nuclear Information System (INIS)

    Winkel, D; Bol, GH; Asselen, B van; Hes, J; Scholten, V; Kerkmeijer, LGW; Raaymakers, BW

    2016-01-01

    Purpose: To develop an automated radiotherapy treatment planning and optimization workflow for prostate cancer in order to generate clinical treatment plans. Methods: A fully automated radiotherapy treatment planning and optimization workflow was developed based on the treatment planning system Monaco (Elekta AB, Stockholm, Sweden). To evaluate our method, a retrospective planning study (n=100) was performed on patients treated for prostate cancer with 5 field intensity modulated radiotherapy, receiving a dose of 35×2Gy to the prostate and vesicles and a simultaneous integrated boost of 35×0.2Gy to the prostate only. A comparison was made between the dosimetric values of the automatically and manually generated plans. Operator time to generate a plan and plan efficiency was measured. Results: A comparison of the dosimetric values show that automatically generated plans yield more beneficial dosimetric values. In automatic plans reductions of 43% in the V72Gy of the rectum and 13% in the V72Gy of the bladder are observed when compared to the manually generated plans. Smaller variance in dosimetric values is seen, i.e. the intra- and interplanner variability is decreased. For 97% of the automatically generated plans and 86% of the clinical plans all criteria for target coverage and organs at risk constraints are met. The amount of plan segments and monitor units is reduced by 13% and 9% respectively. Automated planning requires less than one minute of operator time compared to over an hour for manual planning. Conclusion: The automatically generated plans are highly suitable for clinical use. The plans have less variance and a large gain in time efficiency has been achieved. Currently, a pilot study is performed, comparing the preference of the clinician and clinical physicist for the automatic versus manual plan. Future work will include expanding our automated treatment planning method to other tumor sites and develop other automated radiotherapy workflows.

  1. Movement of the cervix in after-loading brachytherapy: implications for designing external-beam radiotherapy boost fields.

    Science.gov (United States)

    Hombaiah, U; Blake, P; Bidmead, M

    2006-05-01

    Women with invasive carcinoma of the cervix treated by chemo-radiotherapy and brachytherapy may also receive a pelvic sidewall boost using a midline shield (MLS). The purpose of this study was to assess the usefulness of implanted gold grains in detecting the movement of the cervix caused by the insertion of low-dose-rate brachytherapy applicators, and its implications in designing the MLS. The medical records of 42 women with various stages of cervical carcinoma, who were treated by radical chemo-radiotherapy, were reviewed. All of these women underwent examination under anaesthesia (EUA) and a gold-grain insertion to demarcate the vaginal tumour extent, in the antero-posterior and lateral planes, before starting external-beam radiotherapy. The isocentric orthogonal films (simulator films) of external radiotherapy and brachytherapy were compared to assess the change in position of the gold grains and the consequences for the design of the MLS for parametrial and pelvic sidewall boosts. A significant shift in the position of the gold grains was noted in both the x (lateral) and the y (cranial/caudal) axes. The median shift of the midline, right and left lateral gold grains was 4.5, 5 and 7 mm in the x axis, whereas it was 10, 8 and 9.5 mm in the y axis, respectively. The median shift in the x and y axes was 5.5 and 9 mm, ranging from 1 to 40 mm and 1 to 45 mm, respectively. The gold grains were shifted cranially in 34 (80%) and laterally in 29 (69%) women. Thirty-two women (76.2%) received parametrial boost radiotherapy, of which 25 (59.5%) women had a customised, pear-shaped shield, and the remaining seven (16.7%) had a straight-sided, rectangular MLS. Four women (9.5%) relapsed locally, and three of them had been treated using a customised shield. In two of these four women, there was an absolute under-dosage of the central pelvis at the tip of the intra-uterine tube by 50% of the parametrial boost dose (5.4 Gy/3 fractions/3 days). Insertion of the gold grains

  2. A boost to the French hydraulic plan; Relance du plan hydraulique francais

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    A plan for boosting the hydroelectric power generation in France is presented, the first step of an energy policy based on the conclusions of the Grenelle Environnement Forum which targets a 23 percent objective for the renewable energies in France by 2020. Hydroelectricity represents nowadays 12 percent of total electric power generation. The plan is composed of three parts: attribution of concessions will be opened to competition (concessions of the 400 largest dams will be renewed); investments in dams will be strongly encouraged and assisted by the government in order to increase France's hydraulic power generation capacities and enhance its security of power supply - small and micro hydraulic power generation is to be developed; the quality of river waters will be improved.

  3. Image-Guided Radiotherapy for Prostate Cancer: A Prospective Trial of Concomitant Boost Using Indium-111-Capromab Pendetide (ProstaScint) Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wong, William W., E-mail: wong.william@mayo.edu [Department of Radiation Oncology, Mayo Clinic Arizona, Scottsdale, AZ (United States); Schild, Steven E.; Vora, Sujay A.; Ezzell, Gary A. [Department of Radiation Oncology, Mayo Clinic Arizona, Scottsdale, AZ (United States); Nguyen, Ba D.; Ram, Panol C.; Roarke, Michael C. [Department of Radiology, Mayo Clinic Arizona, Scottsdale, AZ (United States)

    2011-11-15

    Purpose: To evaluate, in a prospective study, the use of {sup 111}In-capromab pendetide (ProstaScint) scan to guide the delivery of a concomitant boost to intraprostatic region showing increased uptake while treating the entire gland with intensity-modulated radiotherapy for localized prostate cancer. Methods and Materials: From September 2002 to November 2005, 71 patients were enrolled. Planning pelvic CT and {sup 111}In-capromab pendetide scan images were coregistered. The entire prostate gland received 75.6 Gy/42 fractions, whereas areas of increased uptake in {sup 111}In-capromab pendetide scan received 82 Gy. For patients with T3/T4 disease, or Gleason score {>=}8, or prostate-specific antigen level >20 ng/mL, 12 months of adjuvant androgen deprivation therapy was given. In January 2005 the protocol was modified to give 6 months of androgen deprivation therapy to patients with a prostate-specific antigen level of 10-20 ng/mL or Gleason 7 disease. Results: Thirty-one patients had low-risk, 30 had intermediate-risk, and 10 had high-risk disease. With a median follow-up of 66 months, the 5-year biochemical control rates were 94% for the entire cohort and 97%, 93%, and 90% for low-, intermediate-, and high-risk groups, respectively. Maximum acute and late urinary toxicities were Grade 2 for 38 patients (54%) and 28 patients (39%) and Grade 3 for 1 and 3 patients (4%), respectively. One patient had Grade 4 hematuria. Maximum acute and late gastrointestinal toxicities were Grade 2 for 32 patients (45%) and 15 patients (21%), respectively. Most of the side effects improved with longer follow-up. Conclusion: Concomitant boost to areas showing increased uptake in {sup 111}In-capromab pendetide scan to 82 Gy using intensity-modulated radiotherapy while the entire prostate received 75.6 Gy was feasible and tolerable, with 94% biochemical control rate at 5 years.

  4. SU-F-T-349: Dosimetric Comparison of Three Different Simultaneous Integrated Boost Irradiation Techniques for Multiple Brain Metastases: Intensity-Modulatedradiotherapy, Hybrid Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lin, X; Sun, T; Yin, Y [Shandong Cancer Hospital and Institute, China, Jinan, Shandong (China)

    2016-06-15

    Purpose: To study the dosimetric impact of intensity-modulated radiotherapy (IMRT), hybrid intensity-modulated radiotherapy (h-IMRT) and volumetric modulated arc therapy(VMAT) for whole-brain radiotherapy (WBRT) with simultaneous integrated boost in patients with multiple brain metastases. Methods: Ten patients with multiple brain metastases were included in this analysis. The prescribed dose was 45 Gy to the whole brain (PTVWBRT) and 55 Gy to individual brain metastases (PTVboost) delivered simultaneously in 25 fractions. Three treatment techniques were designed: the 7 equal spaced fields IMRT plan, hybrid IMRT plan and VMAT with two 358°arcs. In hybrid IMRT plan, two fields(90°and 270°) were planned to the whole brain. This was used as a base dose plan. Then 5 fields IMRT plan was optimized based on the two fields plan. The dose distribution in the target, the dose to the organs at risk and total MU in three techniques were compared. Results: For the target dose, conformity and homogeneity in PTV, no statistically differences were observed in the three techniques. For the maximum dose in bilateral lens and the mean dose in bilateral eyes, IMRT and h-IMRT plans showed the highest and lowest value respectively. No statistically significant differences were observed in the dose of optic nerve and brainstem. For the monitor units, IMRT and VMAT plans showed the highest and lowest value respectively. Conclusion: For WBRT with simultaneous integrated boost in patients with multiple brain metastases, hybrid IMRT could reduce the doses to lens and eyes. It is feasible for patients with brain metastases.

  5. Defining bowel dose volume constraints for bladder radiotherapy treatment planning.

    Science.gov (United States)

    McDonald, F; Waters, R; Gulliford, S; Hall, E; James, N; Huddart, R A

    2015-01-01

    Increases to radiotherapy dose are constrained by normal tissue effects. The relationship between bowel dose volume data and late bowel toxicity in patients with muscle-invasive bladder cancer treated with radical radiotherapy was assessed. The bowel was contoured retrospectively on radiotherapy plans of 47 patients recruited to the BC2001 trial (CRUK/01/004). The relationship between bowel volume at various dose levels and prospectively collected late bowel toxicity was explored. Fifteen per cent and 6% of patients experienced grade 1 and grade 2 or more late bowel toxicity, respectively. The mean bowel volume was significantly less at doses ≥50 Gy in those treated with reduced high dose volume radiotherapy compared with standard radiotherapy. The probability of late bowel toxicity increased as bowel volume increased (P ≤ 0.05 for dose levels 30-50 Gy). No grade 2 or more late bowel toxicity was observed in patients with bowel volumes under the thresholds given in the model that predict for 25% probability of late bowel toxicity. There is a dose volume effect for late bowel toxicity in radical bladder radiotherapy. We have modelled the probability of late bowel toxicity from absolute bowel volumes to guide clinicians in assessing radical bladder radiotherapy plans. Thresholds predicting for a 25% probability of late bowel toxicity are proposed as dose volume constraints. Copyright © 2014. Published by Elsevier Ltd.

  6. 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.

  7. 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

  8. Patients with hip prosthesis: radiotherapy treatment planning considerations

    International Nuclear Information System (INIS)

    Ganesh, K.M.; Supe, Sanjay S.

    2000-01-01

    The number of patients with hip prosthesis undergoing radiotherapy for pelvic cancer worldwide is increasing. This might be of importance depending on the materials in the prosthesis and whether any of the treatment fields are involved in the prosthesis. Radiotherapy planning involving the pelvic region of patients having total hip prosthesis has been found to be difficult due to the effect of the prosthesis on the dose distribution. This review is intended to project dosimetric considerations and possible solutions to this uncommon problem

  9. Change in the Quality of Life in Oropharyngeal, Laryngeal and Hypopharyngeal Cancer Patients treated with Volumetric Modulated Arc-Based Concomitant Boost Radiotherapy.

    Science.gov (United States)

    Kannan, P; Mukherji, A; Saravanan, K; Reddy, K S; Vivekanandam, S; Shamsudheen, C; Santhosh, V

    2016-05-01

    To assess the change in the quality of life (QOL) in Oropharyngeal, Laryngeal and Hypopharyngeal cancer patients treated with concomitant boost radiotherapy by Volumetric Intensity Modulated Arc Therapy (VMAT) technique. Thirty patients with oropharynx, larynx or hypopharynx cancers of stage II to IVA were treated with an Accelerated fractionation schedule using Concomitant boost. The dose given was 1.8Gy/fraction daily, 5 days a week to the large field for 28 fractions and a daily concomitant boost of 1.5Gy/fraction to the boost field over the last 12 treatment days for a total dose of 68.4Gy/40 fractions/5½weeks by VMAT technique with concurrent chemotherapy (in stage III and IV patients) using Cisplatin 100mg/m2 IV three weekly during week 1 and week 4 of irradiation. QOL was assessed using the European Organization of Research and Treatment of Cancer Quality of Life Core Questionnaire, version 3.0 (EORTC QLQC30) and EORTC head and neck module (EORTC QLQ-HN35) before treatment, at the end of treatment, 1 month, 3 months and 6 months post treatment. The QOL scores and their evolution over the five measurements were calculated. The change in the QOL scores was acceptable in general. There was a significant reduction in quality of life scores at the end of treatment. The QOL improved in the followup period; and by 3 months post irradiation, there was a return of QOL scores to the baseline value. The QOL scores indicate that concomitant boost radiotherapy by VMAT is well tolerated and helps in rapid return to baseline quality of life scores. We believe that this is one of the first papers which have combined concomitant boost radiotherapy with VMAT technique in head and neck cancers. VMAT based concomitant boost radiotherapy helps in rapid return to baseline quality of life.

  10. Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Janjan, Nora A.; Crane, Christopher N.; Feig, Barry W.; Cleary, Karen; Dubrow, Ronelle; Curley, Steven A.; Ellis, Lee M.; Vauthey, Jean-Nicolas; Lenzi, Renato; Lynch, Patrick; Wolff, Robert; Brown, Thomas; Pazdur, Richard; Abbruzzese, James; Hoff, Paulo M.; Allen, Pamela; Brown, Barry; Skibber, John

    2000-01-01

    Rationale: To evaluate the response to a concomitant boost given during standard chemoradiation for locally advanced rectal cancer. Methods and Materials: Concomitant boost radiotherapy was administered preoperatively to 45 patients with locally advanced rectal cancer in a prospective trial. Treatment consisted of 45 Gy to the pelvis with 18 mV photons at 1.8 Gy/fraction using a 3-field belly board technique with continuous infusion 5FU chemotherapy (300mg/m 2 ) 5 days per week. The boost was given during the last week of therapy with a 6-hour inter-fraction interval to the tumor plus a 2-3 cm margin. The boost dose equaled 7.5 Gy/5 fractions (1.5 Gy/fraction); a total dose of 52.5 Gy/5 weeks was given to the primary tumor. Pretreatment tumor stage, determined by endorectal ultrasound and CT scan, included 29 with T3N0 [64%], 11 T3N1, 1 T3Nx, 2 T4N0, 1 T4N3, and 1 with TxN1 disease. Mean distance from the anal verge was 5 cm (range 0-13 cm). Median age was 55 years (range 33-77 years). The population consisted of 34 males and 11 females. Median time of follow-up is 8 months (range 1-24 months). Results: Sphincter preservation (SP) has been accomplished in 33 of 42 (79%) patients resected to date. Three patients did not undergo resection because of the development of metastatic disease in the interim between the completion of chemoradiation (CTX/XRT) and preoperative evaluation. The surgical procedures included proctectomy and coloanal anastomosis (n = 16), low anterior resection (n = 13), transanal resection (n = 4). Tumor down-staging was pathologically confirmed in 36 of the 42 (86%) resected patients, and 13 (31%) achieved a pathologic CR. Among the 28 tumors (67%) located <6 cm from the anal verge, SP was accomplished in 21 cases (75%). Although perioperative morbidity was higher, toxicity rates during CTX/XRT were comparable to that seen with conventional fractionation. Compared to our contemporary experience with conventional CTX/XRT (45Gy; 1.8 Gy per

  11. Radiotherapy

    International Nuclear Information System (INIS)

    Zedgenidze, G.A.; Kulikov, V.A.; Mardynskij, Yu.S.

    1984-01-01

    The technique for roentgenotopometric and medicamentous preparation of patients for radiotherapy has been reported in detail. The features of planning and performing of remote, intracavitary and combined therapy in urinary bladder cancer are considered. The more effective methods of radiotherapy have been proposed taking into account own experience as well as literature data. The comparative evaluation of treatment results and prognosis are given. Radiation pathomorphism of tumors and tissues of urinary bladder is considered in detail. The problems of diagnosis, prophylaxis and treatment of complications following radiodiagnosis and radiotherapy in patients with urinary bladder cancer are illustrated widely

  12. 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

  13. Magnetic resonance imaging in radiotherapy treatment planning

    NARCIS (Netherlands)

    Moerland, Marinus Adriaan

    1996-01-01

    From its inception in the early 1970's up to the present, magnetic resonance imaging (MRI) has evolved into a sophisticated technique, which has aroused considerable interest in var- ious subelds of medicine including radiotherapy. MRI is capable of imaging in any plane and does not use ionizing

  14. Integration of the radiotherapy irradiation planning in the digital workflow

    International Nuclear Information System (INIS)

    Roehner, F.; Schmucker, M.; Henne, K.; Bruggmoser, G.; Grosu, A.L.; Frommhold, H.; Heinemann, F.E.; Momm, F.

    2013-01-01

    Background and purpose: At the Clinic of Radiotherapy at the University Hospital Freiburg, all relevant workflow is paperless. After implementing the Operating Schedule System (OSS) as a framework, all processes are being implemented into the departmental system MOSAIQ. Designing a digital workflow for radiotherapy irradiation planning is a large challenge, it requires interdisciplinary expertise and therefore the interfaces between the professions also have to be interdisciplinary. For every single step of radiotherapy irradiation planning, distinct responsibilities have to be defined and documented. All aspects of digital storage, backup and long-term availability of data were considered and have already been realized during the OSS project. Method: After an analysis of the complete workflow and the statutory requirements, a detailed project plan was designed. In an interdisciplinary workgroup, problems were discussed and a detailed flowchart was developed. The new functionalities were implemented in a testing environment by the Clinical and Administrative IT Department (CAI). After extensive tests they were integrated into the new modular department system. Results and conclusion: The Clinic of Radiotherapy succeeded in realizing a completely digital workflow for radiotherapy irradiation planning. During the testing phase, our digital workflow was examined and afterwards was approved by the responsible authority. (orig.)

  15. SU-E-T-596: Axillary Nodes Radiotherapy Boost Field Dosimetric Impact Study: Oblique Field and Field Optimization in 3D Conventional Breast Cancer Radiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Su, M [Mount Sinai School of Medicine, Elmhurst, NY (United States); Sura, S

    2014-06-01

    Purpose: To evaluate dosimetric impact of two axillary nodes (AX) boost techniques: (1) posterior-oblique optimized field boost (POB), (2) traditional posterior-anterior boost (PAB) with field optimization (O-PAB), for a postmastectomy breast patient with positive axillary lymph nodes. Methods: Five patients, 3 left and 2 right chest walls, were included in this study. All patients were simulated in 5mm CT slice thickness. Supraclavicular (SC) and level I/II/III AX were contoured based on the RTOG atlas guideline. Five treatment plans, (1) tangential chest wall, (2) oblique SC including AX, (3) PAB, O-PAB and POB, were created for each patient. Three plan sums (PS) were generated by sum one of (3) plan with plan (1) and (2). The field optimization was done through PS dose distribution, which included a field adjustment, a fractional dose, a calculation location and a gantry angle selection for POB. A dosimetric impact was evaluated by comparing a SC and AX coverage, a PS maximum dose, an irradiated area percentage volume received dose over 105% prescription dose (V105), an ipsi-laterial mean lung dose (MLD), an ipsi-laterial mean humeral head dose (MHHD), a mean heart dose (MHD) (for left case only) and their DVH amount these three technique. Results: O-PAB, POB and PAB dosimetric results showed that there was no significant different on SC and AX coverage (p>0.43) and MHD (p>0.16). The benefit of sparing lung irradiation from PAB to O-PAB to POB was significant (p<0.004). PAB showed a highest PS maximum dose (p<0.005), V105 (p<0.023) and MLD (compared with OPAB, p=0.055). MHHD showed very sensitive to the patient arm positioning and anatomy. O-PAB convinced a lower MHHD than PAB (p=0.03). Conclusion: 3D CT contouring plays main role in accuracy radiotherapy. Dosimetric advantage of POB and O-PAB was observed for a better normal tissue irradiation sparing.

  16. Prostate-specific antigen kinetics following hypofractionated stereotactic body radiotherapy boost as post-external beam radiotherapy versus conventionally fractionated external beam radiotherapy for localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Jeong Hoon Phak

    2016-03-01

    Conclusion: Patients treated with SBRT boost after WP-EBRT experienced a lower PSA nadir and there tended to be a continuously greater rate of decline of PSA for durations of 2 years, 3 years, and 4 years than with CF-EBRT. The improved PSA kinetics of SBRT boost over CF-EBRT led to favorable BCF free survival.

  17. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

    International Nuclear Information System (INIS)

    Ken, Soléakhéna; Cassol, Emmanuelle; Delannes, Martine; Celsis, Pierre; Cohen-Jonathan, Elizabeth Moyal; Laprie, Anne; Vieillevigne, Laure; Franceries, Xavier; Simon, Luc; Supper, Caroline; Lotterie, Jean-Albert; Filleron, Thomas; Lubrano, Vincent; Berry, Isabelle

    2013-01-01

    To integrate 3D MR spectroscopy imaging (MRSI) in the treatment planning system (TPS) for glioblastoma dose painting to guide simultaneous integrated boost (SIB) in intensity-modulated radiation therapy (IMRT). For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT), one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE). Fusion assessment was performed for 160 transformations. It resulted in maximum differences <1.00 mm for translation parameters and ≤1.15° for rotation. Dosimetry plans of 72-Gy SIB-IMRT and 60-Gy IMRT showed a significantly decreased maximum dose to the brainstem (44.00 and 44.30 vs. 57.01 Gy) and decreased high dose-volumes to normal brain (19 and 20 vs. 23% and 7 and 7 vs. 12%) compared to 60-Gy 3D-CRT (p < 0.05). Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies

  18. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost.

    Science.gov (United States)

    Ken, Soléakhéna; Vieillevigne, Laure; Franceries, Xavier; Simon, Luc; Supper, Caroline; Lotterie, Jean-Albert; Filleron, Thomas; Lubrano, Vincent; Berry, Isabelle; Cassol, Emmanuelle; Delannes, Martine; Celsis, Pierre; Cohen-Jonathan, Elizabeth Moyal; Laprie, Anne

    2013-01-02

    To integrate 3D MR spectroscopy imaging (MRSI) in the treatment planning system (TPS) for glioblastoma dose painting to guide simultaneous integrated boost (SIB) in intensity-modulated radiation therapy (IMRT). For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT), one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE). Fusion assessment was performed for 160 transformations. It resulted in maximum differences <1.00 mm for translation parameters and ≤1.15° for rotation. Dosimetry plans of 72-Gy SIB-IMRT and 60-Gy IMRT showed a significantly decreased maximum dose to the brainstem (44.00 and 44.30 vs. 57.01 Gy) and decreased high dose-volumes to normal brain (19 and 20 vs. 23% and 7 and 7 vs. 12%) compared to 60-Gy 3D-CRT (p < 0.05). Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies.

  19. 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.

  20. Radiotherapy Breast Boost With Reduced Whole-Breast Dose Is Associated With Improved Cosmesis: The Results of a Comprehensive Assessment From the St. George and Wollongong Randomized Breast Boost Trial

    International Nuclear Information System (INIS)

    Hau, Eric; Browne, Lois H.; Khanna, Sam; Cail, Stacy; Cert, Grad; Chin, Yaw; Clark, Catherine; Inder, Stephanie; Szwajcer, Alison; Graham, Peter H.

    2012-01-01

    Purpose: To evaluate comprehensively the effect of a radiotherapy boost on breast cosmetic outcomes after 5 years in patients treated with breast-conserving surgery. Methods: The St. George and Wollongong trial (NCT00138814) randomized 688 patients with histologically proven Tis-2, N 0–1, M0 carcinoma to the control arm of 50 Gy in 25 fractions (342 patients) and the boost arm of 45 Gy in 25 fractions to the whole breast followed by a 16 Gy in 8 fraction electron boost (346 patients). Five-year cosmetic outcomes were assessed by a panel subjectively in 385 patients and objectively using pBRA (relative breast retraction assessment). A subset of patients also had absolute BRA measurements. Clinician assessment and patient self-assessment of overall cosmetic and specific items as well as computer BCCT.core analysis were also performed. Results: The boost arm had improved cosmetic overall outcomes as scored by the panel and BCCT.core software with 79% (p = 0.016) and 81% (p = 0.004) excellent/good cosmesis respectively compared with 68% in no-boost arm. The boost arm also had lower pBRA and BRA values with a mean difference of 0.60 and 1.82 mm, respectively, but was not statistically significant. There was a very high proportion of overall excellent/good cosmetic outcome in 95% and 93% in the boost and no–boost arms using patient self-assessment. However, no difference in overall and specific items scored by clinician assessment and patient self-assessment was found. Conclusion: The results show the negative cosmetic effect of a 16-Gy boost is offset by a lower whole-breast dose of 45 Gy.

  1. Radiotherapy Breast Boost With Reduced Whole-Breast Dose Is Associated With Improved Cosmesis: The Results of a Comprehensive Assessment From the St. George and Wollongong Randomized Breast Boost Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hau, Eric, E-mail: helloerico@yahoo.com [Cancer Care Centre, St. George Hospital, Kogarah, Sydney (Australia); Browne, Lois H.; Khanna, Sam; Cail, Stacy; Cert, Grad; Chin, Yaw; Clark, Catherine; Inder, Stephanie; Szwajcer, Alison; Graham, Peter H. [Cancer Care Centre, St. George Hospital, Kogarah, Sydney (Australia)

    2012-02-01

    Purpose: To evaluate comprehensively the effect of a radiotherapy boost on breast cosmetic outcomes after 5 years in patients treated with breast-conserving surgery. Methods: The St. George and Wollongong trial (NCT00138814) randomized 688 patients with histologically proven Tis-2, N 0-1, M0 carcinoma to the control arm of 50 Gy in 25 fractions (342 patients) and the boost arm of 45 Gy in 25 fractions to the whole breast followed by a 16 Gy in 8 fraction electron boost (346 patients). Five-year cosmetic outcomes were assessed by a panel subjectively in 385 patients and objectively using pBRA (relative breast retraction assessment). A subset of patients also had absolute BRA measurements. Clinician assessment and patient self-assessment of overall cosmetic and specific items as well as computer BCCT.core analysis were also performed. Results: The boost arm had improved cosmetic overall outcomes as scored by the panel and BCCT.core software with 79% (p = 0.016) and 81% (p = 0.004) excellent/good cosmesis respectively compared with 68% in no-boost arm. The boost arm also had lower pBRA and BRA values with a mean difference of 0.60 and 1.82 mm, respectively, but was not statistically significant. There was a very high proportion of overall excellent/good cosmetic outcome in 95% and 93% in the boost and no-boost arms using patient self-assessment. However, no difference in overall and specific items scored by clinician assessment and patient self-assessment was found. Conclusion: The results show the negative cosmetic effect of a 16-Gy boost is offset by a lower whole-breast dose of 45 Gy.

  2. Clinical implementation of coverage probability planning for nodal boosting in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Ramlov, Anne; Assenholt, Marianne S; Jensen, Maria F

    2017-01-01

    PURPOSE: To implement coverage probability (CovP) for dose planning of simultaneous integrated boost (SIB) of pathologic lymph nodes in locally advanced cervical cancer (LACC). MATERIAL AND METHODS: CovP constraints for SIB of the pathological nodal target (PTV-N) with a central dose peak...

  3. SU-E-P-21: Impact of MLC Position Errors On Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chengqiang, L; Yin, Y; Chen, L [Shandong Cancer Hospital and Institute, 440 Jiyan Road, Jinan, 250117 (China)

    2015-06-15

    Purpose: To investigate the impact of MLC position errors on simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for patients with nasopharyngeal carcinoma. Methods: To compare the dosimetric differences between the simulated plans and the clinical plans, ten patients with locally advanced NPC treated with SIB-IMRT were enrolled in this study. All plans were calculated with an inverse planning system (Pinnacle3, Philips Medical System{sub )}. Random errors −2mm to 2mm{sub )},shift errors{sub (} 2mm,1mm and 0.5mm) and systematic extension/ contraction errors (±2mm, ±1mm and ±0.5mm) of the MLC leaf position were introduced respectively into the original plans to create the simulated plans. Dosimetry factors were compared between the original and the simulated plans. Results: The dosimetric impact of the random and system shift errors of MLC position was insignificant within 2mm, the maximum changes in D95% of PGTV,PTV1,PTV2 were-0.92±0.51%,1.00±0.24% and 0.62±0.17%, the maximum changes in the D0.1cc of spinal cord and brainstem were 1.90±2.80% and −1.78±1.42%, the maximum changes in the Dmean of parotids were1.36±1.23% and −2.25±2.04%.However,the impact of MLC extension or contraction errors was found significant. For 2mm leaf extension errors, the average changes in D95% of PGTV,PTV1,PTV2 were 4.31±0.67%,4.29±0.65% and 4.79±0.82%, the averaged value of the D0.1cc to spinal cord and brainstem were increased by 7.39±5.25% and 6.32±2.28%,the averaged value of the mean dose to left and right parotid were increased by 12.75±2.02%,13.39±2.17% respectively. Conclusion: The dosimetric effect was insignificant for random MLC leaf position errors up to 2mm. There was a high sensitivity to dose distribution for MLC extension or contraction errors.We should pay attention to the anatomic changes in target organs and anatomical structures during the course,individual radiotherapy was recommended to ensure adaptive doses.

  4. Breast-conserving therapy: radiotherapy margins for breast tumor bed boost

    NARCIS (Netherlands)

    Topolnjak, Rajko; van Vliet-Vroegindeweij, Corine; Sonke, Jan-Jakob; Minkema, Danny; Remeijer, Peter; Nijkamp, Jasper; Elkhuizen, Paula; Rasch, Coen

    2008-01-01

    To quantify the interfraction position variability of the excision cavity (EC) and to compare the rib and breast surface as surrogates for the cavity. Additionally, we sought to determine the required margin for on-line, off-line and no correction protocols in external beam radiotherapy. A total of

  5. A virtual reality solution for evaluation of radiotherapy plans

    DEFF Research Database (Denmark)

    Patel, Daniel; Muren, Ludvig; Mehus, Anfinn

    2007-01-01

    This report presents a VR system for evaluation of treatment plans used in radiotherapy (RT), developed to improve the understanding of the spatial relationships between the patient anatomy and the calculated dose distribution. The VR system offers visualization through interactive volume rendering...

  6. A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

    International Nuclear Information System (INIS)

    Lewis, Lorraine; Cox, Jennifer; Morgia, Marita; Atyeo, John; Lamoury, Gillian

    2015-01-01

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

  7. A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Lorraine [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Cox, Jennifer [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Morgia, Marita [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Atyeo, John [Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Lamoury, Gillian [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia)

    2015-09-15

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

  8. Solid Mesh Registration for Radiotherapy Treatment Planning

    DEFF Research Database (Denmark)

    Noe, Karsten Østergaard; Sørensen, Thomas Sangild

    2010-01-01

    We present an algorithm for solid organ registration of pre-segmented data represented as tetrahedral meshes. Registration of the organ surface is driven by force terms based on a distance field representation of the source and reference shapes. Registration of internal morphology is achieved using...... on phantom data and prostate data obtained in vivo based on fiducial marker accuracy and inverse consistency of transformations. The parallel nature of the method allows an efficient implementation on a GPU and as a result the method is very fast. All validation registrations take less than 30 seconds...... to complete. The proposed method has many potential uses in image guided radiotherapy (IGRT) which relies on registration to account for organ deformation between treatment sessions....

  9. Characterisation of radiotherapy planning volumes using textural analysis.

    Science.gov (United States)

    Nailon, William H; Redpath, Anthony T; McLaren, Duncan B

    2008-01-01

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach.

  10. Characterisation of radiotherapy planning volumes using textural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nailon, William H.; Redpath, Anthony T.; McLaren, Duncan B. (Dept. of Oncology Physics, Edinburgh Cancer Centre, Western General Hospital, Edinburgh (United Kingdom))

    2008-08-15

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach

  11. Bayesian network models for error detection in radiotherapy plans

    Science.gov (United States)

    Kalet, Alan M.; Gennari, John H.; Ford, Eric C.; Phillips, Mark H.

    2015-04-01

    The purpose of this study is to design and develop a probabilistic network for detecting errors in radiotherapy plans for use at the time of initial plan verification. Our group has initiated a multi-pronged approach to reduce these errors. We report on our development of Bayesian models of radiotherapy plans. Bayesian networks consist of joint probability distributions that define the probability of one event, given some set of other known information. Using the networks, we find the probability of obtaining certain radiotherapy parameters, given a set of initial clinical information. A low probability in a propagated network then corresponds to potential errors to be flagged for investigation. To build our networks we first interviewed medical physicists and other domain experts to identify the relevant radiotherapy concepts and their associated interdependencies and to construct a network topology. Next, to populate the network’s conditional probability tables, we used the Hugin Expert software to learn parameter distributions from a subset of de-identified data derived from a radiation oncology based clinical information database system. These data represent 4990 unique prescription cases over a 5 year period. Under test case scenarios with approximately 1.5% introduced error rates, network performance produced areas under the ROC curve of 0.88, 0.98, and 0.89 for the lung, brain and female breast cancer error detection networks, respectively. Comparison of the brain network to human experts performance (AUC of 0.90 ± 0.01) shows the Bayes network model performs better than domain experts under the same test conditions. Our results demonstrate the feasibility and effectiveness of comprehensive probabilistic models as part of decision support systems for improved detection of errors in initial radiotherapy plan verification procedures.

  12. Impact of gantry rotation time on plan quality and dosimetric verification. Volumetric modulated arc therapy (VMAT) vs. intensity modulated radiotherapy (IMRT)

    International Nuclear Information System (INIS)

    Pasler, Marlies; Wirtz, Holger; Lutterbach, Johannes

    2011-01-01

    To compare plan quality criteria and dosimetric accuracy of step-and-shoot intensity-modulated radiotherapy (ss-IMRT) and volumetric modulated arc radiotherapy (VMAT) using two different gantry rotation times. This retrospective planning study based on 20 patients was comprised of 10 prostate cancer (PC) and 10 head and neck (HN) cancer cases. Each plan contained two target volumes: a primary planning target volume (PTV) and a boost volume. For each patient, one ss-IMRT plan and two VMAT plans at 90 s (VMAT90) and 120 s (VMAT120) per arc were generated with the Pinnacle copyright planning system. Two arcs were provided for the PTV plans and a single arc for boost volumes. Dosimetric verification of the plans was performed using a 2D ionization chamber array placed in a full scatter phantom. VMAT reduced delivery time and monitor units for both treatment sites compared to IMRT. VMAT120 vs. VMAT90 increased delivery time and monitor units in PC plans without improving plan quality. For HN cases, VMAT120 provided comparable organs at risk sparing and better target coverage and conformity than VMAT90. In the VMAT plan verification, an average of 97.1% of the detector points passed the 3 mm, 3% γ criterion, while in IMRT verification it was 98.8%. VMAT90, VMAT120, and IMRT achieved comparable treatment plans. Slower gantry movement in VMAT120 plans only improves dosimetric quality for highly complex targets.

  13. Impact of gantry rotation time on plan quality and dosimetric verification. Volumetric modulated arc therapy (VMAT) vs. intensity modulated radiotherapy (IMRT)

    Energy Technology Data Exchange (ETDEWEB)

    Pasler, Marlies; Wirtz, Holger; Lutterbach, Johannes [Gemeinschaftspraxis fuer Strahlentherapie Singen-Friedrichshafen, Singen (Germany)

    2011-12-15

    To compare plan quality criteria and dosimetric accuracy of step-and-shoot intensity-modulated radiotherapy (ss-IMRT) and volumetric modulated arc radiotherapy (VMAT) using two different gantry rotation times. This retrospective planning study based on 20 patients was comprised of 10 prostate cancer (PC) and 10 head and neck (HN) cancer cases. Each plan contained two target volumes: a primary planning target volume (PTV) and a boost volume. For each patient, one ss-IMRT plan and two VMAT plans at 90 s (VMAT90) and 120 s (VMAT120) per arc were generated with the Pinnacle {sup copyright} planning system. Two arcs were provided for the PTV plans and a single arc for boost volumes. Dosimetric verification of the plans was performed using a 2D ionization chamber array placed in a full scatter phantom. VMAT reduced delivery time and monitor units for both treatment sites compared to IMRT. VMAT120 vs. VMAT90 increased delivery time and monitor units in PC plans without improving plan quality. For HN cases, VMAT120 provided comparable organs at risk sparing and better target coverage and conformity than VMAT90. In the VMAT plan verification, an average of 97.1% of the detector points passed the 3 mm, 3% {gamma} criterion, while in IMRT verification it was 98.8%. VMAT90, VMAT120, and IMRT achieved comparable treatment plans. Slower gantry movement in VMAT120 plans only improves dosimetric quality for highly complex targets.

  14. Interpretation of Gamma Index for Quality Assurance of Simultaneously Integrated Boost (SIB) IMRT Plans for Head and Neck Carcinoma

    Science.gov (United States)

    Atiq, Maria; Atiq, Atia; Iqbal, Khalid; Shamsi, Quratul ain; Andleeb, Farah; Buzdar, Saeed Ahmad

    2017-12-01

    Objective: The Gamma Index is prerequisite to estimate point-by-point difference between measured and calculated dose distribution in terms of both Distance to Agreement (DTA) and Dose Difference (DD). This study aims to inquire what percentage of pixels passing a certain criteria assure a good quality plan and suggest gamma index as efficient mechanism for dose verification of Simultaneous Integrated Boost Intensity Modulated Radiotherapy plans. Method: In this study, dose was calculated for 14 head and neck patients and IMRT Quality Assurance was performed with portal dosimetry using the Eclipse treatment planning system. Eclipse software has a Gamma analysis function to compare measured and calculated dose distribution. Plans of this study were deemed acceptable when passing rate was 95% using tolerance for Distance to agreement (DTA) as 3mm and Dose Difference (DD) as 5%. Result and Conclusion: Thirteen cases pass tolerance criteria of 95% set by our institution. Confidence Limit for DD is 9.3% and for gamma criteria our local CL came out to be 2.0% (i.e., 98.0% passing). Lack of correlation was found between DD and γ passing rate with R2 of 0.0509. Our findings underline the importance of gamma analysis method to predict the quality of dose calculation. Passing rate of 95% is achieved in 93% of cases which is adequate level of accuracy for analyzed plans thus assuring the robustness of SIB IMRT treatment technique. This study can be extended to investigate gamma criteria of 5%/3mm for different tumor localities and to explore confidence limit on target volumes of small extent and simple geometry.

  15. 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

  16. Approximating convex Pareto surfaces in multiobjective radiotherapy planning

    International Nuclear Information System (INIS)

    Craft, David L.; Halabi, Tarek F.; Shih, Helen A.; Bortfeld, Thomas R.

    2006-01-01

    Radiotherapy planning involves inherent tradeoffs: the primary mission, to treat the tumor with a high, uniform dose, is in conflict with normal tissue sparing. We seek to understand these tradeoffs on a case-to-case basis, by computing for each patient a database of Pareto optimal plans. A treatment plan is Pareto optimal if there does not exist another plan which is better in every measurable dimension. The set of all such plans is called the Pareto optimal surface. This article presents an algorithm for computing well distributed points on the (convex) Pareto optimal surface of a multiobjective programming problem. The algorithm is applied to intensity-modulated radiation therapy inverse planning problems, and results of a prostate case and a skull base case are presented, in three and four dimensions, investigating tradeoffs between tumor coverage and critical organ sparing

  17. Methods and computer readable medium for improved radiotherapy dosimetry planning

    Science.gov (United States)

    Wessol, Daniel E.; Frandsen, Michael W.; Wheeler, Floyd J.; Nigg, David W.

    2005-11-15

    Methods and computer readable media are disclosed for ultimately developing a dosimetry plan for a treatment volume irradiated during radiation therapy with a radiation source concentrated internally within a patient or incident from an external beam. The dosimetry plan is available in near "real-time" because of the novel geometric model construction of the treatment volume which in turn allows for rapid calculations to be performed for simulated movements of particles along particle tracks therethrough. The particles are exemplary representations of alpha, beta or gamma emissions emanating from an internal radiation source during various radiotherapies, such as brachytherapy or targeted radionuclide therapy, or they are exemplary representations of high-energy photons, electrons, protons or other ionizing particles incident on the treatment volume from an external source. In a preferred embodiment, a medical image of a treatment volume irradiated during radiotherapy having a plurality of pixels of information is obtained.

  18. Automatic liver contouring for radiotherapy treatment planning

    Science.gov (United States)

    Li, Dengwang; Liu, Li; Kapp, Daniel S.; Xing, Lei

    2015-09-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems. The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours. The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  19. Monte Carlo treatment planning with modulated electron radiotherapy: framework development and application

    Science.gov (United States)

    Alexander, Andrew William

    optimization algorithms are demonstrated. We investigated the clinical significance of MERT on spinal irradiation, breast boost irradiation, and a head and neck sarcoma cancer site using several parameters to analyze the treatment plans. Finally, we investigated the idea of mixed beam photon and electron treatment planning. Photon optimization treatment planning tools were included within the MERT planning toolkit for the purpose of mixed beam optimization. In conclusion, this thesis work has resulted in the development of an advanced framework for photon and electron Monte Carlo treatment planning studies and the development of an inverse planning system for photon, electron or mixed beam radiotherapy (MBRT). The justification and validation of this work is found within the results of the planning studies, which have demonstrated dosimetric advantages to using MERT or MBRT in comparison to clinical treatment alternatives.

  20. Automatic planning on hippocampal avoidance whole-brain radiotherapy

    International Nuclear Information System (INIS)

    Wang, Shuo; Zheng, Dandan; Zhang, Chi; Ma, Rongtao; Bennion, Nathan R.; Lei, Yu; Zhu, Xiaofeng; Enke, Charles A.; Zhou, Sumin

    2017-01-01

    Mounting evidence suggests that radiation-induced damage to the hippocampus plays a role in neurocognitive decline for patients receiving whole-brain radiotherapy (WBRT). Hippocampal avoidance whole-brain radiotherapy (HA-WBRT) has been proposed to reduce the putative neurocognitive deficits by limiting the dose to the hippocampus. However, urgency of palliation for patients as well as the complexities of the treatment planning may be barriers to protocol enrollment to accumulate further clinical evidence. This warrants expedited quality planning of HA-WBRT. Pinnacle 3 Automatic treatment planning was designed to increase planning efficiency while maintaining or improving plan quality and consistency. The aim of the present study is to evaluate the performance of the Pinnacle 3 Auto-Planning on HA-WBRT treatment planning. Ten patients previously treated for brain metastases were selected. Hippocampal volumes were contoured on T1 magnetic resonance (MR) images, and planning target volumes (PTVs) were generated based on RTOG0933. The following 2 types of plans were generated by Pinnacle 3 Auto-Planning: the one with 2 coplanar volumetric modulated arc therapy (VMAT) arcs and the other with 9-field noncoplanar intensity-modulated radiation therapy (IMRT). D 2% and D 98% of PTV were used to calculate homogeneity index (HI). HI and Paddick Conformity index (CI) of PTV as well as D 100% and D max of the hippocampus were used to evaluate the plan quality. All the auto-plans met the dose coverage and constraint objectives based on RTOG0933. The auto-plans eliminated the necessity of generating pseudostructures by the planners, and it required little manual intervention which expedited the planning process. IMRT quality assurance (QA) results also suggest that all the auto-plans are practically acceptable on delivery. Pinnacle 3 Auto-Planning generates acceptable plans by RTOG0933 criteria without time-consuming planning process. The expedited quality planning achieved by

  1. Electron Density Calibration for Radiotherapy Treatment Planning

    International Nuclear Information System (INIS)

    Herrera-Martinez, F.; Rodriguez-Villafuerte, M.; Martinez-Davalos, A.; Ruiz-Trejo, C.; Celis-Lopez, M. A.; Larraga-Gutierrez, J. M.; Garcia-Garduno, A.

    2006-01-01

    Computed tomography (CT) images are used as basic input data for most modern radiosurgery treatment planning systems (TPS). CT data not only provide anatomic information to delineate target volumes, but also allow the introduction of corrections for tissue inhomogeneities into dose calculations during the treatment planning procedure. These corrections involve the determination of a relationship between tissue electron density (ρe) and their corresponding Hounsfield Units (HU). In this work, an elemental analysis of different commercial tissue equivalent materials using Scanning Electron Microscopy was carried out to characterize their chemical composition. The tissue equivalent materials were chosen to ensure a large range of ρe to be included in the CT scanner calibration. A phantom was designed and constructed with these materials to simulate the size of a human head

  2. Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

    Science.gov (United States)

    Pommer, Tobias; Falk, Marianne; Poulsen, Per R.; Keall, Paul J.; O'Brien, Ricky T.; Meidahl Petersen, Peter; Rosenschöld, Per Munck af

    2013-04-01

    This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume of the prostate. The impact on plan quality of optimizations with a leaf position constraint, which limited the distance between neighbouring adjacent MLC leaves, was also investigated. Deliveries were done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average pass rate with DMLC tracking was 99.9% (range 98.7-100%, measurement as reference), whereas the pass rate for untracked deliveries decreased distinctly as the average displacement increased, with an average pass rate of 61.3% (range 32.7-99.3%). Dose-volume histograms showed that DMLC tracking maintained the planned dose distributions in the presence of motion whereas traces with >3 mm average displacement caused clear plan degradation for untracked deliveries. The dose to the rectum and bladder had an evident dependence on the motion direction and amplitude for untracked deliveries, and the dose to the rectum was slightly increased for IPL boosted plans compared to conventional plans for anterior motion with large amplitude. In conclusion, optimization using a leaf position

  3. Dosimetry audit simulation of treatment planning system in multicenters radiotherapy

    Science.gov (United States)

    Kasmuri, S.; Pawiro, S. A.

    2017-07-01

    Treatment Planning System (TPS) is an important modality that determines radiotherapy outcome. TPS requires input data obtained through commissioning and the potentially error occurred. Error in this stage may result in the systematic error. The aim of this study to verify the TPS dosimetry to know deviation range between calculated and measurement dose. This study used CIRS phantom 002LFC representing the human thorax and simulated all external beam radiotherapy stages. The phantom was scanned using CT Scanner and planned 8 test cases that were similar to those in clinical practice situation were made, tested in four radiotherapy centers. Dose measurement using 0.6 cc ionization chamber. The results of this study showed that generally, deviation of all test cases in four centers was within agreement criteria with average deviation about -0.17±1.59 %, -1.64±1.92 %, 0.34±1.34 % and 0.13±1.81 %. The conclusion of this study was all TPS involved in this study showed good performance. The superposition algorithm showed rather poor performance than either analytic anisotropic algorithm (AAA) and convolution algorithm with average deviation about -1.64±1.92 %, -0.17±1.59 % and -0.27±1.51 % respectively.

  4. Multiobjective approach in plans for treatment of cancer by radiotherapy

    Directory of Open Access Journals (Sweden)

    Thalita Monteiro Obal

    2013-08-01

    Full Text Available Nowadays the technique of radiotherapy has been one of the main alternatives for the treatment of several types of cancer today. With technological development, especially in the case of 3D conformal radiotherapy, applications involving mathematical techniques and algorithms have been proposed to help the development a good treatment plan. This paper aims at present a model for multiobjective linear programming problem of dose intensity. The focus of the model is to determine the best dose distribution of radiation field, so that the dose delivered to the tumor to be prescribed and that affects the minimum the noble and healthy tissues. A test case of prostate cancer was used as an example of the numerical model and the Pareto-Optimal Frontier was generated using the method of weighted function.

  5. Multi-objective optimization of inverse planning for accurate radiotherapy

    International Nuclear Information System (INIS)

    Cao Ruifen; Pei Xi; Cheng Mengyun; Li Gui; Hu Liqin; Wu Yican; Jing Jia; Li Guoli

    2011-01-01

    The multi-objective optimization of inverse planning based on the Pareto solution set, according to the multi-objective character of inverse planning in accurate radiotherapy, was studied in this paper. Firstly, the clinical requirements of a treatment plan were transformed into a multi-objective optimization problem with multiple constraints. Then, the fast and elitist multi-objective Non-dominated Sorting Genetic Algorithm (NSGA-II) was introduced to optimize the problem. A clinical example was tested using this method. The results show that an obtained set of non-dominated solutions were uniformly distributed and the corresponding dose distribution of each solution not only approached the expected dose distribution, but also met the dose-volume constraints. It was indicated that the clinical requirements were better satisfied using the method and the planner could select the optimal treatment plan from the non-dominated solution set. (authors)

  6. Optimization of rotational radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Tulovsky, Vladimir; Ringor, Michael; Papiez, Lech

    1995-01-01

    Purpose: Rotational therapy treatment planning for rotationally symmetric geometry of tumor and healthy tissue provides an important example of testing various approaches to optimizing dose distributions for therapeutic x-ray irradiations. In this article, dose distribution optimization is formulated as a variational problem. This problem is solved analytically and numerically. Methods and Materials: The classical Lagrange method is used to derive equations and inequalities that give necessary conditions for minimizing the mean-square deviation between the ideal dose distribution and the achievable dose distribution. The solution of the resulting integral equation with Cauchy kernel is used to derive analytical formulas for the minimizing irradiation intensity function. Results: The solutions are evaluated numerically and the graphs of the minimizing intensity functions and the corresponding dose distributions are presented. Conclusions: The optimal solutions obtained using the mean-square criterion lead to significant underdosage in some areas of the tumor volume. Possible solutions to this shortcoming are investigated and medically more appropriate criteria for optimization are proposed for future investigations

  7. Hypofractionated radiotherapy and stereotactic boost with concurrent and adjuvant temozolamide for glioblastoma in good performance status elderly patients – early results of a phase II trial.

    Directory of Open Access Journals (Sweden)

    Scott eFloyd

    2012-10-01

    Full Text Available Glioblastoma Multiforme (GBM is an aggressive primary brain neoplasm with dismal prognosis. Based on successful phase III trials, 60 Gy involved-field radiotherapy in 30 fractions over 6 weeks (Standard RT with concurrent and adjuvant temozolomide is currently the standard of care. In this disease, age and Karnofsky Performance Status (KPS are the most important prognostic factors. For elderly patients, clinical trials comparing standard RT with radiotherapy abbreviated to 40 Gy in 15 fractions over 3 weeks demonstrated similar outcomes, indicating shortened radiotherapy may be an appropriate option for elderly patients. However, these trials did not include temozolomide chemotherapy, and included patients with poor KPS, possibly obscuring benefits of more aggressive treatment for some elderly patients. We conducted a prospective Phase II trial to examine the efficacy of a hypofractionated radiation course followed by a stereotactic boost with concurrent and adjuvant temozolomide chemotherapy in elderly patients with good performance status. In this study, patients 65 years and older with a KPS >70 and histologically confirmed GBM received 40 Gy in 15 fractions with 3D conformal technique followed by a 1-3 fraction stereotactic boost to the enhancing tumor. All patients also received concurrent and adjuvant temozolomide. Patients were evaluated 1 month post-treatment and every 2 months thereafter. Between 2007 and 2010, 20 patients (9 males and 11 females were enrolled in this study. The median age was 75.4 years (range 65-87 years. At a median follow-up of 11 months (range 7-32 months, 12 patients progressed and 5 are alive. The median progression free survival was 11 months and the median overall survival was 13 months. There was no additional toxicity. These results indicate that elderly patients with good KPS can achieve outcomes comparable to the current standard of care using an abbreviated radiotherapy course, radiosurgery boost and

  8. Ongoing development of digital radiotherapy plan review tools

    International Nuclear Information System (INIS)

    Ebert, M.A.; Hatton, J.; Cornes, D.

    2011-01-01

    Full text: To describe ongoing development of software to support the review of radiotherapy treatment planning system (TPS) data. The 'SWAN' software program was conceived in 2000 and initially developed for the RADAR (TROG 03.04) prostate radiotherapy trial. Validation of the SWAN program has been occurring via implementation by TROG in support of multiple clinical trials. Development has continued and the SWAN software program is now supported by modular components which comprise the 'SW AN system'. This provides a comprehensive set of tools for the review, analysis and archive of TPS exports. The SWAN system has now been used in support of over 20 radiotherapy trials and to review the plans of over 2,000 trial participants. The use of the system for the RADAR trial is now culminating in the derivation of dose-outcomes indices for prostate treatment toxicity. Newly developed SWAN tools include enhanced remote data archive/retrieval, display of dose in both relative and absolute modes, and interfacing to a Matlab-based add-on ('VAST') that allows quantitative analysis of delineated volumes including regional overlap statistics for multi-observer studies. Efforts are continuing to develop the SWAN system in the context of international collaboration aimed at harmonising the quality-assurance activities of collaborative trials groups. Tools such as the SWAN system are essential for ensuring the collection of accurate and reliable evidence to guide future radiotherapy treatments. One of the principal challenges of developing such a tool is establishing a development path that will ensure its validity and applicability well into the future.

  9. Intensity-modulated radiotherapy with simultaneous modulated accelerated boost technique and chemotherapy in patients with nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Fareed, Muhammad M; AlAmro, Abdullah S; Bayoumi, Yasser; Tunio, Mutahir A; Ismail, Abdul S; Akasha, Rashad; Mubasher, Mohamed; Al Asiri, Mushabbab

    2013-01-01

    To present our experience of intensity-modulated radiotherapy (IMRT) with simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Sixty eight patients of NPC were treated between April 2006 and December 2011 including 45 males and 23 females with mean age of 46 (range 15–78). Stage distribution was; stage I 3, stage II 7, stage III 26 and stage IV 32. Among 45 (66.2%) evaluated patients for presence of Epstein-Barr virus (EBV), 40 (88.8%) were positive for EBV. Median radiation doses delivered to gross tumor volume (GTV) and positive neck nodes were 66–70 Gy, 63 Gy to clinical target volume (CTV) and 50.4 Gy to clinically negative neck. In addition 56 (82.4%) patients with bulky tumors (T4/N2+) received neoadjuvant chemotherapy 2–3 cycles (Cisplatin/Docetaxel or Cisplatin/Epirubicin or Cisplatin/5 Flourouracil). Concurrent chemotherapy with radiation was weekly Cisplatin 40 mg/m 2 (40 patients) or Cisplatin 100 mg/m 2 (28 patients). With a median follow up of 20 months (range 3–43), one patient developed local recurrence, two experienced regional recurrences and distant failure was seen in 3 patients. Estimated 3 year disease free survival (DFS) was 94%. Three year DFS for patients with EBV was 100% as compared to 60% without EBV (p = 0.0009). Three year DFS for patients with undifferentiated histology was 98% as compared to 82% with other histologies (p = 0.02). Acute grade 3 toxicity was seen as 21 (30.9%) having G-III mucositis and 6 (8.8%) with G-III skin reactions. Late toxicity was minimal and loss of taste was seen in 3 patients (7.5%) at time of analysis. IMRT with SMART in combination with chemotherapy is feasible and effective in terms of both the clinical response and safety profile. EBV, histopathology and nodal involvement were found important prognostic factors for locoregional recurrence

  10. Improved Planning Time and Plan Quality Through Multicriteria Optimization for Intensity-Modulated Radiotherapy

    International Nuclear Information System (INIS)

    Craft, David L.; Hong, Theodore S.; Shih, Helen A.; Bortfeld, Thomas R.

    2012-01-01

    Purpose: To test whether multicriteria optimization (MCO) can reduce treatment planning time and improve plan quality in intensity-modulated radiotherapy (IMRT). Methods and Materials: Ten IMRT patients (5 with glioblastoma and 5 with locally advanced pancreatic cancers) were logged during the standard treatment planning procedure currently in use at Massachusetts General Hospital (MGH). Planning durations and other relevant planning information were recorded. In parallel, the patients were planned using an MCO planning system, and similar planning time data were collected. The patients were treated with the standard plan, but each MCO plan was also approved by the physicians. Plans were then blindly reviewed 3 weeks after planning by the treating physician. Results: In all cases, the treatment planning time was vastly shorter for the MCO planning (average MCO treatment planning time was 12 min; average standard planning time was 135 min). The physician involvement time in the planning process increased from an average of 4.8 min for the standard process to 8.6 min for the MCO process. In all cases, the MCO plan was blindly identified as the superior plan. Conclusions: This provides the first concrete evidence that MCO-based planning is superior in terms of both planning efficiency and dose distribution quality compared with the current trial and error–based IMRT planning approach.

  11. Registration and planning of radiotherapy and proton therapy treatment

    International Nuclear Information System (INIS)

    Bausse, Jerome

    2010-01-01

    Within the frame of an update and renewal project, the Orsay Proton Therapy Centre of the Curie Institute (IPCO) renews its software used for the treatment of patients by proton therapy, a radiotherapy technique which uses proton beams. High energies used in these treatments and the precision provided by proton particle characteristics require a more precise patient positioning than conventional radiotherapy: proton therapy requires a precision of about a millimetre. Thus, markers are placed on the skull which are generally well accepted by patients, but are a problem in the case of paediatric treatment, notably for the youngest children whose skull is still growing. The first objective of this research is thus to use only intrinsic information from X-ray images used when positioning the patient. A second objective is to make the new software (TPS Isogray) perfectly compatible with IPCO requirements by maintaining the strengths of the previous TPS (Treatment Planning System) and being prepared to the implementation of a new installation. After a presentation of the context and state of the art in radiotherapy and patient positioning, the author proposes an overview of 2D registration methods, presents a new method for 2x2D registration, and addresses the problem of 3D registration. Then, after a presentation of proton therapy, the author addresses different specific issues and aspects: the compensator (simulation, calculation, and tests), dose calculation, the 'Pencil-Beam' algorithm, tests, and introduced improvements [fr

  12. Stereotactic Body Radiotherapy: A Promising Treatment Option for the Boost of Oropharyngeal Cancers Not Suitable for Brachytherapy: A Single-Institutional Experience

    Energy Technology Data Exchange (ETDEWEB)

    Al-Mamgani, Abrahim, E-mail: a.al-mamgani@erasmusmc.nl [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk, Rotterdam (Netherlands); Tans, Lisa; Teguh, David N. [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk, Rotterdam (Netherlands); Rooij, Peter van [Department of Biostatistics, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk, Rotterdam (Netherlands); Zwijnenburg, Ellen M.; Levendag, Peter C. [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk, Rotterdam (Netherlands)

    2012-03-15

    Purpose: To prospectively assess the outcome and toxicity of frameless stereotactic body radiotherapy (SBRT) as a treatment option for boosting primary oropharyngeal cancers (OPC) in patients who not suitable for the standard brachytherapy boost (BTB). Methods and Materials: Between 2005 and 2010, 51 patients with Stage I to IV biopsy-proven OPC who were not suitable for BTB received boosts by means of SBRT (3 times 5.5 Gy, prescribed to the 80% isodose line), after 46 Gy of IMRT to the primary tumor and neck (when indicated). Endpoints of the study were local control (LC), disease-free survival (DFS), overall survival (OS), and acute and late toxicity. Results: After a median follow-up of 18 months (range, 6-65 months), the 2-year actuarial rates of LC, DFS, and OS were 86%, 80%, and 82%, respectively, and the 3-year rates were 70%, 66%, and 54%, respectively. The treatment was well tolerated, as there were no treatment breaks and no Grade 4 or 5 toxicity reported, either acute or chronic. The overall 2-year cumulative incidence of Grade {>=}2 late toxicity was 28%. Of the patients with 2 years with no evidence of disease (n = 20), only 1 patient was still feeding tube dependent and 2 patients had Grade 3 xerostomia. Conclusions: According to our knowledge, this study is the first report of patients with primary OPC who received boosts by means of SBRT. Patients with OPC who are not suitable for the standard BTB can safely and effectively receive boosts by SBRT. With this radiation technique, an excellent outcome was achieved. Furthermore, the SBRT boost did not have a negative impact regarding acute and late side effects.

  13. Intraoperative radiotherapy (IORT) with low-energy photons as a boost in patients with early-stage oral cancer with the indications for postoperative radiotherapy. Treatment feasibility and preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Rutkowski, Tomasz; Wygoda, Andrzej; Hutnik, Marcin; Skladowski, Krzysztof; Wydmanski, Jerzy; Maciejewski, Boguslaw [Dept. of Radiation Oncology, Maria Sklodowska-Curie Memorial Cancer and Inst. of Oncology, Gliwice Branch (Poland); Maciejewski, Adam; Szymczyk, Cezary; Wierzgon, Janusz [Dept. of Surgery, Maria Sklodowska-Curie Memorial Cancer Center and Inst. of Oncology, Gliwice Branch (Poland); Orlef, Andrzej [Dept. of Physics, Maria Sklodowska-Curie Memorial Cancer Center and Inst. of Oncology, Gliwice Branch (Poland)

    2010-09-15

    Purpose: To evaluate the feasibility and preliminary results of intraoperative radiotherapy (IORT) with low-energy photons as a boost in patients with early-stage oral cancer with the indications for postoperative radiotherapy. Patients and Methods: Between 2003 and 2006, 16 patients with early-stage cancer of mobile tongue (n = 10 [63%]) or floor of the mouth (n = 6 [37%]) treated at Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland, were evaluated for IORT boost with the INTRABEAM {sup registered} System (Carl Zeiss Surgical GmbH; IORT-PRS) because of the high risk of local recurrence due to positive margins on frozen pathologic section. After tumor resection, the applicator was positioned in the tumor bed. The applicator's diameter (range: 1.5-5 cm) was selected to encompass high-risk area of tumor recurrence. The dose (5 Gy, 7 Gy, or 7.5 Gy) was applied according to tumor volume and bone proximity. External-beam radiotherapy (EBRT) was provided to the tumor bed in all patients (50 Gy) and to the nodal area, when needed. Toxicity and local tumor control were assessed. Results: Median follow-up was 36 months. IORT did not increase acute mucosal reaction. Local tumor control was found in all cases. Early mucosal reaction did not exceed 3 according to the RTOG scale and healed in median time of 35 days after completion of EBRT. No late adverse effects were observed. Conclusion: This preliminary report has demonstrated the feasibility of IORT-PRS for patients with early oral cancer with the indications for postoperative radiotherapy. This method may be considered an alternative boost technique, although additional studies are needed to establish long-term results in a larger group of patients. (orig.)

  14. Subsets of Women With Close or Positive Margins After Breast-Conserving Surgery With High Local Recurrence Risk Despite Breast Plus Boost Radiotherapy

    International Nuclear Information System (INIS)

    Lupe, Krystine; Truong, Pauline T.; Alexander, Cheryl; Lesperance, Mary; Speers, Caroline; Tyldesley, Scott

    2011-01-01

    Purpose: (1) To examine the effect of surgical margin status on local recurrence (LR) and survival following breast-conserving therapy; (2) To identify subsets with close or positive margins with high LR risk despite whole breast radiotherapy (RT) plus boost. Methods and Materials: Subjects were 2,264 women with pT1–3, any N, M0 invasive breast cancer, treated with breast-conserving surgery and whole breast ± boost RT. Five-year Kaplan-Meier (KM) LR, breast cancer–specific and overall survival (BCSS and OS) were compared between cohorts with negative (n = 1,980), close (n = 222), and positive (n = 62) margins. LR rates were analyzed according to clinicopathologic characteristics. Multivariable Cox regression modeling and matched analysis of close/positive margin cases and negative margin controls were performed. Results: Median follow-up was 5.2 years. Boost RT was used in 92% of patients with close or positive margins. Five-year KM LR rates in the negative, close and positive margin cohorts were 1.3%, 4.0%, and 5.2%, respectively (p = 0.001). BCSS and OS were similar in the three margin subgroups. In the close/positive margin cohort, LR rates were 10.2% with age 10% despite whole breast plus boost RT. These patients should be considered for more definitive surgery.

  15. Hypofractionated boost to the dominant tumor region with intensity modulated stereotactic radiotherapy for prostate cancer: a sequential dose escalation pilot study.

    Science.gov (United States)

    Miralbell, Raymond; Mollà, Meritxell; Rouzaud, Michel; Hidalgo, Alberto; Toscas, José Ignacio; Lozano, Joan; Sanz, Sergi; Ares, Carmen; Jorcano, Sandra; Linero, Dolors; Escudé, Lluís

    2010-09-01

    To evaluate the feasibility, tolerability, and preliminary outcomes in patients with prostate cancer treated according to a hypofractionated dose escalation protocol to boost the dominant tumor-bearing region of the prostate. After conventional fractionated external radiotherapy to 64 to 64.4 Gy, 50 patients with nonmetastatic prostate cancer were treated with an intensity-modulated radiotherapy hypofractionated boost under stereotactic conditions to a reduced prostate volume to the dominant tumor region. A rectal balloon inflated with 60 cc of air was used for internal organ immobilization. Five, 8, and 8 patients were sequentially treated with two fractions of 5, 6, or 7 Gy, respectively (normalized total dose in 2 Gy/fraction [NTD(2 Gy)] 100 Gy, high-dose group). Androgen deprivation was given to 33 patients. Acute and late toxicities were assessed according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer (RTOG/EORTC) scoring system. Two patients presented with Grade 3 acute urinary toxicity. The 5-year probabilities of >or=Grade 2 late urinary and late low gastrointestinal (GI) toxicity-free survival were 82.2% +/- 7.4% and 72.2% +/- 7.6%, respectively. The incidence and severity of acute or late toxicities were not correlated with low- vs. high-dose groups, pelvic irradiation, age, or treatment with or without androgen deprivation. The 5-year biochemical disease-free survival (b-DFS) and disease-specific survival were 98% +/- 1.9% and 100%, respectively. Intensity-modulated radiotherapy hypofractionated boost dose escalation under stereotactic conditions was feasible, and showed excellent outcomes with acceptable long-term toxicity. This approach may well be considered an alternative to high-dose-rate brachytherapy. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  16. Computerized treatment planning systems for external photon beam radiotherapy

    International Nuclear Information System (INIS)

    Evans, M.D.C.

    2005-01-01

    Computerized treatment planning systems (TPSs) are used in external beam radiotherapy to generate beam shapes and dose distributions with the intent to maximize tumour control and minimize normal tissue complications. Patient anatomy and tumour targets can be represented as 3-D models. The entire process of treatment planning involves many steps and the medical physicist is responsible for the overall integrity of the computerized TPS to accurately and reliably produce dose distributions and associated calculations for external beam radiotherapy. The planning itself is most commonly carried out by a dosimetrist, and the plan must be approved by a radiation oncologist before implementation in actual patient treatments. Treatment planning prior to the 1970s was generally carried out through the manual manipulation of standard isodose charts on to patient body contours that were generated by direct tracing or lead wire representation, and relied heavily on the judicious choice of beam weight and wedging by an experienced dosimetrist. The simultaneous development of computed tomography (CT), along with the advent of readily accessible computing power from the 1970s on, led to the development of CT based computerized treatment planning, providing the ability to view dose distributions directly superimposed upon a patient's axial anatomy. The entire treatment planning process involves many steps, beginning from beam data acquisition and entry into the computerized TPS, through patient data acquisition, to treatment plan generation and the final transfer of data to the treatment machine. Successive improvements in treatment planning hardware and software have been most notable in the graphics, calculation and optimization aspects of current systems. Systems encompassing the 'Virtual Patient' are able to display beam's eye views (BEVs) of radiation beams and digitally reconstructed radiographs (DRRs) for arbitrary dose distributions. Dose calculations have evolved from

  17. Knowledge-based computer systems for radiotherapy planning.

    Science.gov (United States)

    Kalet, I J; Paluszynski, W

    1990-08-01

    Radiation therapy is one of the first areas of clinical medicine to utilize computers in support of routine clinical decision making. The role of the computer has evolved from simple dose calculations to elaborate interactive graphic three-dimensional simulations. These simulations can combine external irradiation from megavoltage photons, electrons, and particle beams with interstitial and intracavitary sources. With the flexibility and power of modern radiotherapy equipment and the ability of computer programs that simulate anything the machinery can do, we now face a challenge to utilize this capability to design more effective radiation treatments. How can we manage the increased complexity of sophisticated treatment planning? A promising approach will be to use artificial intelligence techniques to systematize our present knowledge about design of treatment plans, and to provide a framework for developing new treatment strategies. Far from replacing the physician, physicist, or dosimetrist, artificial intelligence-based software tools can assist the treatment planning team in producing more powerful and effective treatment plans. Research in progress using knowledge-based (AI) programming in treatment planning already has indicated the usefulness of such concepts as rule-based reasoning, hierarchical organization of knowledge, and reasoning from prototypes. Problems to be solved include how to handle continuously varying parameters and how to evaluate plans in order to direct improvements.

  18. 3-Dimentional radiotherapy versus conventional treatment plans for gastric cancer

    Directory of Open Access Journals (Sweden)

    Aghili M

    2010-11-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The current standard of adjuvant management for gastric cancer after curative resection based on the results of intergroup 0116 is concurrent chemoradiation. Current guidelines for designing these challenging fields still include two-dimensional simulation with simple AP-PA parallel opposed design. However, the implementation of radiotherapy (RT remains a concern. Our objective was to compare three-dimensional (3D techniques to the more commonly used AP-PA technique."n"nMethods: A total of 24 patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiation with simple AP-PA technique, using Cobalt-60. Total radiation dose was 50.4Gy. Landmark-based fields were simulated to assess PTV coverage. For each patient, three additional radiotherapy treatment plans were generated using three-dimensional (3D technique. The four treatment plans were then compared for target volume coverage and dose to normal tissues (liver, spinal cord, kidneys using dose volume histogram (DVH analysis."n"nResults: The three-dimensional planning techniques provided 10% superior PTV coverage compared to conventional AP-PA fields (p<0.001. Comparative DVHs for the right kidney, left kidney

  19. Predictors of breast radiotherapy plan modifications: quality assurance rounds in a large cancer centre.

    Science.gov (United States)

    Lymberiou, Timothy; Galuszka, Susanne; Lee, Grace; Xu, Wei; Fyles, Anthony; Su, Susie; Purdie, Thomas G; Catton, Pamela; Chung, Caroline; Dinniwell, Robert; Koch, Anne; Levin, Wilfred; Manchul, Lee; Warde, Padraig; Liu, Fei-Fei

    2015-01-01

    This study describes the process and outcomes of breast radiotherapy (RT) quality assurance (QA) rounds, seeking to identify variables associated with plan modifications. Real-time data were prospectively collected over 2 years. Descriptive statistics determined the proportion of cases requiring no (A), minor (B), or major (C) modifications, which were then subjected to univariate and multivariate analyses. A total of 2223 breast cancer QA cases were reviewed; 47 cases (2.1%) underwent a minor, and 52 cases (2.3%) required a major modification. Common changes included boost, volume, seroma, and bolus. On univariate analysis, regional nodal irradiation (RNI), tumour size, and axillary node dissection were significantly associated with major modifications. Upon multivariate analysis, the only independent predictor was RNI (OR 2.12, p=0.0075). For patients with no RNI, RNI had a higher likelihood of plan modifications; a group with low risk of modification was identified, which could direct future re-structuring of QA rounds. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. 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

  1. 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.

  2. Concomitant boost radiotherapy with concurrent weekly cisplatin in advanced head and neck cancers: a phase II trial

    International Nuclear Information System (INIS)

    Kumar, Shaleen; Pandey, Manish; Lal, Punita; Rastogi, Neeraj; Maria Das, K. Joseph; Dimri, Kislay

    2005-01-01

    Background and purpose: To determine the safety and efficacy of concomitant boost radiotherapy (CBRT) with concurrent cisplatin chemotherapy (CT) in advanced head and neck cancers. Patients and methods: Between February 2000 and June 2001, 95 previously untreated patients of advanced head and neck cancers were treated with CBRT and concurrent cisplatin CT. CBRT consisted of: phase I-44 Gy/22fx/4.5 weeks, phase IIa-16 Gy/8fx/1.5 weeks and phase IIb-10 Gy/8fx (delivered as a second daily fraction after a gap of 6 h along with phase IIa). CT (cisplatin 35 mg/m 2 ) was administered weekly usually preceding CBRT by an hour. Results: The median follow-up was 39 months (range 8-50 months). CBRT compliance (70 Gy in 40-44 days) was seen in 66% (63/95). Six cycles of CT was delivered in 73% (69/95). Acute grade III/IV mucosal toxicity was seen in 79% and resulted, on average, in a total weight loss of 7.9 kg from a mean pretreatment weight of 51 kg. Nasogastric tube placements were required in 26% (25/95) for an average duration of 19.3 days. Grade III leucopenia was seen in 2%. Mortality during and within 30 days of treatment was seen in 14% (13/95). Crude incidence of late subcutaneous fibrosis (grade III) was 21% (12/57) and a case of mandibular necrosis and thyroid cartilage necrosis each were seen. Initial loco regional disease clearance was seen in 59% (56/95) and the Kaplan-Meier estimates of 3-year loco-regional control rate and overall survival were 25% (median 7 months, 95% C.I. 3-11) and 27% (median 12 months, 95% C.I. 8-16), respectively. Conclusions: On present evidence, in the settings of a developing country, CBRT with concurrent cisplatin cannot be recommended as primary therapy in advanced head and neck cancers without formal comparison with other treatment modalities

  3. Delivery validation of an automated modulated electron radiotherapy plan

    International Nuclear Information System (INIS)

    Connell, T.; Papaconstadopoulos, P.; Alexander, A.; Serban, M.; Devic, S.; Seuntjens, J.

    2014-01-01

    Purpose: Modulated electron radiation therapy (MERT) represents an active area of interest that offers the potential to improve healthy tissue sparing in treatment of certain cancer cases. Challenges remain however in accurate beamlet dose calculation, plan optimization, collimation method, and delivery accuracy. In this work, the authors investigate the accuracy and efficiency of an end-to-end MERT plan and automated delivery method. Methods: Treatment planning was initiated on a previously treated whole breast irradiation case including an electron boost. All dose calculations were performed using Monte Carlo methods and beam weights were determined using a research-based treatment planning system capable of inverse optimization. The plan was delivered to radiochromic film placed in a water equivalent phantom for verification, using an automated motorized tertiary collimator. Results: The automated delivery, which covered four electron energies, 196 subfields, and 6183 total MU was completed in 25.8 min, including 6.2 min of beam-on time. The remainder of the delivery time was spent on collimator leaf motion and the automated interfacing with the accelerator in service mode. Comparison of the planned and delivered film dose gave 3%/3mm gamma pass rates of 62.1%, 99.8%, 97.8%, 98.3%, and 98.7% for the 9, 12, 16, and 20 MeV, and combined energy deliveries, respectively. Delivery was also performed with a MapCHECK device and resulted in 3%/3  mm gamma pass rates of 88.8%, 86.1%, 89.4%, and 94.8% for the 9, 12, 16, and 20 MeV energies, respectively. Conclusions: Results of the authors’ study showed that an accurate delivery utilizing an add-on tertiary electron collimator is possible using Monte Carlo calculated plans and inverse optimization, which brings MERT closer to becoming a viable option for physicians in treating superficial malignancies

  4. Spatiotemporal radiotherapy planning using a global optimization approach

    Science.gov (United States)

    Adibi, Ali; Salari, Ehsan

    2018-02-01

    This paper aims at quantifying the extent of potential therapeutic gain, measured using biologically effective dose (BED), that can be achieved by altering the radiation dose distribution over treatment sessions in fractionated radiotherapy. To that end, a spatiotemporally integrated planning approach is developed, where the spatial and temporal dose modulations are optimized simultaneously. The concept of equivalent uniform BED (EUBED) is used to quantify and compare the clinical quality of spatiotemporally heterogeneous dose distributions in target and critical structures. This gives rise to a large-scale non-convex treatment-plan optimization problem, which is solved using global optimization techniques. The proposed spatiotemporal planning approach is tested on two stylized cancer cases resembling two different tumor sites and sensitivity analysis is performed for radio-biological and EUBED parameters. Numerical results validate that spatiotemporal plans are capable of delivering a larger BED to the target volume without increasing the BED in critical structures compared to conventional time-invariant plans. In particular, this additional gain is attributed to the irradiation of different regions of the target volume at different treatment sessions. Additionally, the trade-off between the potential therapeutic gain and the number of distinct dose distributions is quantified, which suggests a diminishing marginal gain as the number of dose distributions increases.

  5. Daily CT planning during boost irradiation of prostate cancer. Feasibility and time requirements

    International Nuclear Information System (INIS)

    Geinitz, H.; Zimmermann, F.B.; Kuzmany, A.; Kneschaurek, P.

    2000-01-01

    Background: In the irradiation of prostate cancer internal organ movement leads to uncertainties in the daily localization of the clinical target volume. Therefore more or less large safety margins are added when designing the treatment portals. With daily CT planning internal organ movement can be compensated to some extent, safety margins can be reduced and irradiated normal tissue can be spared. The feasibility of daily CT-based 3D treatment planning is studied in a patient with localized prostate carcinoma using a new patient positioning system. Methods: Daily CT planning was applied during boost irradiation of a patient with prostate cancer: After patient immobilization the pelvis was scanned in 3 mm CT slices. Planning was done with the BrainSCAN planning system for stereotactic body irradiation. The prostate was contoured in all slices and the safety margins of the micromultileafs were automatically set to the distance chosen by the physician (0.8 cm). Patient positioning was done with the BrainLAB ExacTrac positioning system on the basis of skin attached stereotactic body markers. Before each treatment verification images of the isocenter were taken. Results: The total time requirement for planning and irradiation was about 1 hour 15 minutes. Patient positioning on the treatment couch took about 10 minutes. The accuracy of the positioning system was good (75% of the deviations were smaller than 3 mm). The shift of the single markers from CT scan to CT scan was more extensive than those of the center of all 7 markers combined (47% of the deviations were smaller than 3 mm). The location of the markers seems to influence the magnitude of their dislocation. Conclusion: Daily CT planning is feasible but time consuming. The new patient positioning system ExacTrac is an interesting tool especially for daily CT planning since conventional simulation can be omitted. (orig.) [de

  6. Treatment planning and dosimetry in radiotherapy for glottic cancer

    International Nuclear Information System (INIS)

    Fukudomi, Yukimi; Kawakami, Toshiaki; Fujii, Takashi; Kawamura, Masashi; Kataoka, Masaaki; Hamamoto, Ken

    1995-01-01

    To perform a precise radiotherapy and to prevent local failure as low as possible for early glottic cancer, we present data regarding the technical basis of radiotherapy. Thermoluminescent dosimeters (TLDs) were embedded at 6 locations in a hand-made Mix-Dp phantom and exposed to two lateral-opposed beams using 6 x 6 cm 2 fields. The dosimeters were irradiated using 4 MV-X, 6 MV-X and 10 MV-X with open-field, 15deg and 30deg wedge filter (WF) made of Pb or Fe, and a hand-made Mix-Dp WF compensating irregular skin surface which was placed apart from the patient's skin to preserve skin-sparing properties. Calculation of absorbed dose with a computer for treatment planning was performed. Using 6 MV-X and a 30deg WF, the dose distribution was the best in this phantom. With 10 MV-X, the absorbed dose at the anterior glottis was 6.7-11.6% lower than the administered dose. Using a Mix-Dp WF, the dose distribution was better than those using WF made of Pb or Fe. Under various types of treatments, the absorbed dose at the reference point using TLDs were 0.4-5.8% lower than the administered dose calculated with ratio-TAR method at the same point. These are believed to be due to lack of estimation of scatters and poor correcting method for WF factor. We conclude that some experimental checks are desirable to perform a precise radiotherapy for laryngeal cancer. This can be done using a number of TLDs placed at points of interest in a phantom. (author)

  7. A graphical user interface for automatic image registration software designed for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Rajasekar, David; Datta, Niloy R.; Gupta, Rakesh K.; Rao, Sajja

    2004-01-01

    Medical imaging forms a vital component of radiotherapy treatment planning and its evaluation. The integration of the useful data obtained from multiple imaging modalities for radiotherapy planning is achieved by image registration softwares. In radiotherapy planning systems, normally the computed tomography (CT) slices are kept as a standard upon which other modality images (magnetic resonance imaging [MRI], single photon emission computed tomography [SPECT], positron emission tomography [PET], etc.) are aligned-automatically or interactively. Following validation of successful registration, they are resampled and reformatted, as per the requirements. This paper defines the minimum requirements of automatic image registration software for 3-dimensional (3D) radiotherapy planning and describes the implementation of a suitable graphical user interface developed in Visual Basic (version 5). The automatic image registration (AIR) routines freely available from Dr. Roger P. Woods, UCLA, (USA) were used in this software. This software could be easily implemented and was easy to use for image processing suitable for radiotherapy planning systems

  8. "SABER": A new software tool for radiotherapy treatment plan evaluation.

    Science.gov (United States)

    Zhao, Bo; Joiner, Michael C; Orton, Colin G; Burmeister, Jay

    2010-11-01

    Both spatial and biological information are necessary in order to perform true optimization of a treatment plan and for predicting clinical outcome. The goal of this work is to develop an enhanced treatment plan evaluation tool which incorporates biological parameters and retains spatial dose information. A software system is developed which provides biological plan evaluation with a novel combination of features. It incorporates hyper-radiosensitivity using the induced-repair model and applies the new concept of dose convolution filter (DCF) to simulate dose wash-out effects due to cell migration, bystander effect, and/or tissue motion during treatment. Further, the concept of spatial DVH (sDVH) is introduced to evaluate and potentially optimize the spatial dose distribution in the target volume. Finally, generalized equivalent uniform dose is derived from both the physical dose distribution (gEUD) and the distribution of equivalent dose in 2 Gy fractions (gEUD2) and the software provides three separate models for calculation of tumor control probability (TCP), normal tissue complication probability (NTCP), and probability of uncomplicated tumor control (P+). TCP, NTCP, and P+ are provided as a function of prescribed dose and multivariable TCP, NTCP, and P+ plots are provided to illustrate the dependence on individual parameters used to calculate these quantities. Ten plans from two clinical treatment sites are selected to test the three calculation models provided by this software. By retaining both spatial and biological information about the dose distribution, the software is able to distinguish features of radiotherapy treatment plans not discernible using commercial systems. Plans that have similar DVHs may have different spatial and biological characteristics and the application of novel tools such as sDVH and DCF within the software may substantially change the apparent plan quality or predicted plan metrics such as TCP and NTCP. For the cases examined

  9. Specification and acceptance testing of radiotherapy treatment planning systems

    International Nuclear Information System (INIS)

    2007-04-01

    Quality assurance (QA) in the radiation therapy treatment planning process is essential to ensure accurate dose delivery to the patient and to minimize the possibility of accidental exposure. The computerized radiotherapy treatment planning systems (RTPSs) are now widely available in industrialized and developing countries and it is of special importance to support hospitals in Member States in developing procedures for acceptance testing, commissioning and QA of their RTPSs. Responding to these needs, a group of experts developed an IAEA publication with such recommendations, which was published in 2004 as IAEA Technical Reports Series No. 430. This report provides a general framework and describes a large number of tests and procedures that should be considered by the users of new RTPSs. However, small hospitals with limited resources or large hospitals with high patient load and limited staff are not always able to perform complete characterization, validation and software testing of algorithms used in RTPSs. Therefore, the IAEA proposed more specific guidelines that provide a step-by-step recommendation for users at hospitals or cancer centres how to implement acceptance and commissioning procedures for newly purchased RTPSs. The current publication was developed in the framework of the Coordinated Research Project on Development of Procedures for Quality Assurance for Dosimetry Calculations in Radiotherapy and uses the International Electrotechnical Commission (IEC) standard IEC 62083, Requirements for the Safety of Radiotherapy Treatment Planning Systems as its basis. The report addresses the procedures for specification and acceptance testing of RTPSs to be used by both manufacturers and users at the hospitals. Recommendations are provided for specific tests to be performed at the manufacturing facility known as type tests, and for acceptance tests to be performed at the hospital known as site tests. The purpose of acceptance testing is to demonstrate to the

  10. Effect of patient setup errors on simultaneously integrated boost head and neck IMRT treatment plans

    International Nuclear Information System (INIS)

    Siebers, Jeffrey V.; Keall, Paul J.; Wu Qiuwen; Williamson, Jeffrey F.; Schmidt-Ullrich, Rupert K.

    2005-01-01

    Purpose: The purpose of this study is to determine dose delivery errors that could result from random and systematic setup errors for head-and-neck patients treated using the simultaneous integrated boost (SIB)-intensity-modulated radiation therapy (IMRT) technique. Methods and Materials: Twenty-four patients who participated in an intramural Phase I/II parotid-sparing IMRT dose-escalation protocol using the SIB treatment technique had their dose distributions reevaluated to assess the impact of random and systematic setup errors. The dosimetric effect of random setup error was simulated by convolving the two-dimensional fluence distribution of each beam with the random setup error probability density distribution. Random setup errors of σ = 1, 3, and 5 mm were simulated. Systematic setup errors were simulated by randomly shifting the patient isocenter along each of the three Cartesian axes, with each shift selected from a normal distribution. Systematic setup error distributions with Σ = 1.5 and 3.0 mm along each axis were simulated. Combined systematic and random setup errors were simulated for σ = Σ = 1.5 and 3.0 mm along each axis. For each dose calculation, the gross tumor volume (GTV) received by 98% of the volume (D 98 ), clinical target volume (CTV) D 90 , nodes D 90 , cord D 2 , and parotid D 50 and parotid mean dose were evaluated with respect to the plan used for treatment for the structure dose and for an effective planning target volume (PTV) with a 3-mm margin. Results: Simultaneous integrated boost-IMRT head-and-neck treatment plans were found to be less sensitive to random setup errors than to systematic setup errors. For random-only errors, errors exceeded 3% only when the random setup error σ exceeded 3 mm. Simulated systematic setup errors with Σ = 1.5 mm resulted in approximately 10% of plan having more than a 3% dose error, whereas a Σ = 3.0 mm resulted in half of the plans having more than a 3% dose error and 28% with a 5% dose error

  11. Forward-planned, multiple-segment, tangential fields with concomitant boost in the treatment of breast cancer

    International Nuclear Information System (INIS)

    Mayo, Charles; Lo, Y.C.; Fitzgerald, Thomas J.; Urie, Marcia

    2004-01-01

    We report on the utility of forward-planned, 3-dimensional (3D), multiple-segment tangential fields for radiation treatment of patients with breast cancer. The technique accurately targets breast tissue and the tumor bed and reduces dose inhomogeneity in the target. By decreasing excess dose to the skin and lung, a concomitant boost to the tumor bed can be delivered during the initial treatment, thereby decreasing the overall treatment time by one week. More than 120 breast cancer patients have been treated with this breast conservation technique in our clinic. For each patient, a 3D treatment plan based upon breast and tumor bed volumes delineated on computed tomography (CT) was developed. Segmented tangent fields were iteratively created to reduce 'hot spots' produced by traditional tangents. The tumor bed received a concomitant boost with additional conformal photon beams. The final tumor bed boost was delivered either with conformal photon beams or conventional electron beams. All patients received 45 Gy to the breast target, plus an additional 5 Gy to the surgical excision site, bringing the total dose to 50 Gy to the boost target volume in 25 fractions. The final boost to the excision site brought the total target dose to 60 Gy. With minimum follow-up of 4 months and median follow-up of 11 months, all patients have excellent cosmetic results. There has been minimal breast edema and minimal skin changes. There have been no local relapses to date. Forward planning of multi-segment fields is facilitated with 3D planning and multileaf collimation. The treatment technique offers improvement in target dose homogeneity and the ability to confidently concomitantly boost the excision site. The technique also offers the advantage for physics and therapy staff to develop familiarity with multiple segment fields, as a precursor to intensity-modulated radiation therapy (IMRT) techniques

  12. Radiotherapy

    International Nuclear Information System (INIS)

    Prosnitz, L.R.; Kapp, D.S.; Weissberg, J.B.

    1983-01-01

    This review highlights developments over the past decade in radiotherapy and attempts to summarize the state of the art in the management of the major diseases in which radiotherapy has a meaningful role. The equipment, radiobiology of radiotherapy and carcinoma of the lung, breast and intestines are highlighted

  13. Molecular Imaging to Plan Radiotherapy and Evaluate Its Efficacy.

    Science.gov (United States)

    Jeraj, Robert; Bradshaw, Tyler; Simončič, Urban

    2015-11-01

    Molecular imaging plays a central role in the management of radiation oncology patients. Specific uses of imaging, particularly to plan radiotherapy and assess its efficacy, require an additional level of reproducibility and image quality beyond what is required for diagnostic imaging. Specific requirements include proper patient preparation, adequate technologist training, careful imaging protocol design, reliable scanner technology, reproducible software algorithms, and reliable data analysis methods. As uncertainty in target definition is arguably the greatest challenge facing radiation oncology, the greatest impact that molecular imaging can have may be in the reduction of interobserver variability in target volume delineation and in providing greater conformity between target volume boundaries and true tumor boundaries. Several automatic and semiautomatic contouring methods based on molecular imaging are available but still need sufficient validation to be widely adopted. Biologically conformal radiotherapy (dose painting) based on molecular imaging-assessed tumor heterogeneity is being investigated, but many challenges remain to fully exploring its potential. Molecular imaging also plays increasingly important roles in both early (during treatment) and late (after treatment) response assessment as both a predictive and a prognostic tool. Because of potentially confounding effects of radiation-induced inflammation, treatment response assessment requires careful interpretation. Although molecular imaging is already strongly embedded in radiotherapy, the path to widespread and all-inclusive use is still long. The lack of solid clinical evidence is the main impediment to broader use. Recommendations for practicing physicians are still rather scarce. (18)F-FDG PET/CT remains the main molecular imaging modality in radiation oncology applications. Although other molecular imaging options (e.g., proliferation imaging) are becoming more common, their widespread use is

  14. Inverse planning of energy-modulated electron beams in radiotherapy

    International Nuclear Information System (INIS)

    Gentry, John R.; Steeves, Richard; Paliwal, Bhudatt A.

    2006-01-01

    The use of megavoltage electron beams often poses a clinical challenge in that the planning target volume (PTV) is anterior to other radiosensitive structures and has variable depth. To ensure that skin as well as the deepest extent of the PTV receives the prescribed dose entails prescribing to a point beyond the depth of peak dose for a single electron energy. This causes dose inhomogeneities and heightened potential for tissue fibrosis, scarring, and possible soft tissue necrosis. Use of bolus on the skin improves the entrant dose at the cost of decreasing the therapeutic depth that can be treated. Selection of a higher energy to improve dose homogeneity results in increased dose to structures beyond the PTV, as well as enlargement of the volume receiving heightened dose. Measured electron data from a linear accelerator was used as input to create an inverse planning tool employing energy and intensity modulation using bolus (e-IMRT TM ). Using tools readily available in a radiotherapy department, the applications of energy and intensity modulation on the central axis makes it possible to remove hot spots of 115% or more over the depths clinically encountered. The e-IMRT TM algorithm enables the development of patient-specific dose distributions with user-defined positions of peak dose, range, and reduced dose to points beyond the prescription point

  15. Practical use of computers for the planning of radiotherapy

    International Nuclear Information System (INIS)

    Buenemann, H.; Gauwerky, F.; Langheim, F.; Schirrmeister, D.

    1976-01-01

    The main problems of radiotherapy planning are discussed with respect to use of computers now being available for a greater number of centers. One of the most essential premises is - apart from clear ideas on a modern target volume concept - a sufficiently high speed in producing realistic summarized isodose contours for any radiation therapy arrangement in any individual patient's cross section outline. This problem being solved, those individual summarized isodose figures have to be critically evaluated and therefore the importance of applicable meaning-full optimization criteria come into account. The properties of such criteria, which must be quantifiable, generally applicable and really relevant for judgement on quality of a plan, had to be accepted, before automatic optimization procedures could be developed; principles involved are presented. By means of a short series of examples, namely 60 Co fixed field combinations with and without use of wedges, combinations of arc therapy for a number of clinical tasks. It has been poined out, that most experienced estimate by the eye would have been by far insufficient when compared to the automized computer optimization when using such simple criteria as 1. homogeneity of absorbed dose within target volume, 2. numerically limited absorbed dose within areas of risk, 3. as low as possible radiation effects to all 'outside areas'. (orig./ORU) [de

  16. Heart dose reduction in breast cancer treatment with simultaneous integrated boost. Comparison of treatment planning and dosimetry for a novel hybrid technique and 3D-CRT

    International Nuclear Information System (INIS)

    Joest, Vincent; Kretschmer, Matthias; Sabatino, Marcello; Wuerschmidt, Florian; Dahle, Joerg; Lorenzen, Joern; Ueberle, Friedrich

    2015-01-01

    The present study compares in silico treatment plans of clinically established three-dimensional conformal radiotherapy (3D-CRT) with a hybrid technique consisting of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) during normally fractionated radiation of mammary carcinomas with simultaneous integrated boost on the basis of dose-volume histogram (DVH) parameters. Radiation treatment planning was performed with a hybrid and a 3D-CRT treatment plan for 20 patients. Hybrid plans were implemented with two tangential IMRT fields and a VMAT field in the angular range of the tangents. Verification of the plan was performed with a manufacturer-independent measurement system consisting of a detector array and rotation unit. The mean values of the heart dose for the entire patient collective were 3.6 ± 2.5 Gy for 3D-CRT and 2.9 ± 2.1 Gy for the hybrid technique (p < 0.01). For the left side (n = 10), the mean values for the left anterior descending artery were 21.8 ± 7.4 Gy for 3D-CRT and 17.6 ± 7.4 Gy for the hybrid technique (p < 0.01). The mean values of the ipsilateral lung were 11.9 ± 1.6 Gy for 3D-CRT and 10.5 ± 1.3 Gy for the hybrid technique (p < 0.01). Calculated dose distributions in the hybrid arm were in good accordance with measured dose (on average 95.6 ± 0.5 % for γ < 1 and 3 %/3 mm). The difference of the mean treatment time per fraction was 7 s in favor of 3D-CRT. Compared with the established 3D-CRT technique, the hybrid technique allows for a decrease in dose, particularly of the mean heart and lung dose with comparable target volume acquisition and without disadvantageous low-dose load of contralateral structures. Uncomplicated implementation of the hybrid technique was demonstrated in this context. The hybrid technique combines the advantages of tangential IMRT with the superior sparing of organs at risk by VMAT. (orig.) [de

  17. Prostate-specific antigen kinetics after stereotactic body radiotherapy as monotherapy or boost after whole pelvic radiotherapy for localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Hun Jung Kim

    2015-12-01

    Conclusions: In this report of low- and intermediate-risk prostate cancer patients, an initial period of rapid PSA decline was followed by a slow decline, which resulted in a lower PSA nadir. The PSA kinetics of SBRT monotherapy appears to be comparable to those achieved with SBRT boost with WPRT.

  18. Safety Improvement in Radiotherapy Treatment Plan. Planning vs Redundant Check vs in vivo Dosimetry

    International Nuclear Information System (INIS)

    Torres Diaz, J.; Ascencion Ybarra, Y.; La Fuentes Rosales, L. de; Lara Mas, E.; Larrinaga Cortinas, E.

    2013-01-01

    In Cuba it is mandatory to have an independent monitor units check before any radiotherapy treatment is started. The main objective of this paper is to enhance the safety of the radiotherapy planning by developing and testing a practical tool to double check the monitor units calculation for external beam high energy photon therapy. A software for monitor units (MUs) verification was designed and coded. It considers the common in clinical practice isocentric set-ups. The in vivo dosimetry measurements were done with a silicon diode system for 6 MV photon beams to support the validation of the software. The results show a discrepancy within 5% between the 3 methods which is in accordance with international recommendations. (Author)

  19. Feasibility of curative radiotherapy with a concomitant boost technique in 33 patients with non-small cell lung cancer (NSCLC)

    NARCIS (Netherlands)

    Schuster-Uitterhoeve, A. L.; Hulshof, M. C.; Gonzàlez Gonzàlez, D.; Koolen, M.; Sminia, P.

    1993-01-01

    Thirty-three patients with an inoperable NSCLC were treated with a dose of 60 Gy/20 fractions/25 days, using a concomitant boost technique. A dose of 40 Gy/2 Gy/25 days was given to the tumor area and a part (15 patients) or the whole (18 patients) mediastinum. During each session a simultaneous

  20. Is it beneficial to selectively boost high-risk tumor subvolumes? A comparison of selectively boosting high-risk tumor subvolumes versus homogeneous dose escalation of the entire tumor based on equivalent EUD plans

    International Nuclear Information System (INIS)

    Kim, Yusung; To me, Wolfgang A.

    2008-01-01

    Purpose. To quantify and compare expected local tumor control and expected normal tissue toxicities between selective boosting IMRT and homogeneous dose escalation IMRT for the case of prostate cancer. Methods. Four different selective boosting scenarios and three different high-risk tumor subvolume geometries were designed to compare selective boosting and homogeneous dose escalation IMRT plans delivering the same equivalent uniform dose (EUD) to the entire PTV. For each scenario, differences in tumor control probability between both boosting strategies were calculated for the high-risk tumor subvolume and remaining low-risk PTV, and were visualized using voxel based iso-TCP maps. Differences in expected rectal and bladder complications were quantified using radiobiological indices (generalized EUD (gEUD) and normal tissue complication probability (NTCP)) as well as %-volumes. Results. For all investigated scenarios and high-risk tumor subvolume geometries, selective boosting IMRT improves expected TCP compared to homogeneous dose escalation IMRT, especially when lack of control of the high-risk tumor subvolume could be the cause for tumor recurrence. Employing, selective boosting IMRT significant increases in expected TCP can be achieved for the high-risk tumor subvolumes. The three conventional selective boosting IMRT strategies, employing physical dose objectives, did not show significant improvement in rectal and bladder sparing as compared to their counterpart homogeneous dose escalation plans. However, risk-adaptive optimization, utilizing radiobiological objective functions, resulted in reduction in NTCP for the rectum when compared to its corresponding homogeneous dose escalation plan. Conclusions. Selective boosting is a more effective method than homogeneous dose escalation for achieving optimal treatment outcomes. Furthermore, risk-adaptive optimization increases the therapeutic ratio as compared to conventional selective boosting IMRT

  1. Radiotherapy

    Directory of Open Access Journals (Sweden)

    Rema Jyothirmayi

    1999-01-01

    Full Text Available Purpose. Conservative treatment in the form of limited surgery and post-operative radiotherapy is controversial in hand and foot sarcomas, both due to poor radiation tolerance of the palm and sole, and due to technical difficulties in achieving adequate margins.This paper describes the local control and survival of 41 patients with soft tissue sarcoma of the hand or foot treated with conservative surgery and radiotherapy. The acute and late toxicity of megavoltage radiotherapy to the hand and foot are described. The technical issues and details of treatment delivery are discussed. The factors influencing local control after radiotherapy are analysed.

  2. Comparative planning study for proton radiotherapy of benign brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, L.; Nicolini, G.; Fogliata, A. [Medical Physics, Oncology Inst. of Southern Switzerland, Bellinzona (Switzerland); Clivio, A.; Vanetti, E. [Medical Physics, Oncology Inst. of Southern Switzerland, Bellinzona (Switzerland); Medical Physics Specialization School, Univ. of Milan (Italy)

    2006-07-15

    Purpose: a comparative study of different systems for proton-based radiotherapy was conducted. Material and methods: the Paul Scherrer Institute method for spot scanning was compared with the systems for passive scattering from the helax-TMS and the varian eclipse. Twelve cases of ''benign'' brain tumors were considered (meningiomas, neurinomas, and hypophyseal adenomas). Organs at risk included chiasm, brainstem, eyes and optic nerves as well as the not otherwise specified healthy brain tissue in view of long-term toxicity. Results: the results showed that high target coverage was achievable (V{sub 90} > 98% for all systems). Plans designed with the spot-scanning technique presented the minimum involvement of healthy tissue (e.g., the lowest maximum significant dose to healthy brain [25.6 Gy] or the lowest conformity index [CI{sub 95} = 1.3], between 38% and 46% lower than for the other techniques). Conclusion: in this study, no definitive indication of superiority of any technique can be drawn but spot scanning can better conform dose distributions and minimize the irradiation of healthy volumes at medium to low dose levels, a factor of interest when long life expectancy is considered. (orig.)

  3. A prospective phase I comparison of toxicity and cosmesis outcomes of single-fraction IORT and hypofractionated radiotherapy with IORT boost in early-stage breast cancer.

    Science.gov (United States)

    Bhandari, Tanuja; Babaran, Wesley; Forouzannia, Afshin; Williams, Venita; Harness, Jay; Carpenter, Michele; Gobran, Maher; Khanijou, Rajesh; Wagman, Brittany; Ash, Robert; Wagman, Lawrence D

    Radiation therapy is proven to reduce local recurrence in patients with early-stage breast cancer. To reduce toxicity, treatment time, and improve accuracy, intraoperative radiation therapy was used as definitive treatment or as a boost. The study's objective was to compare the short-term toxicity and cosmesis of single-fraction (SF) IORT and hypofractionated radiotherapy with IORT boost (HfB) given as definitive treatment. Between March 2011 and December 2013, 57 patients aged 45-91 years and 24 patients aged 43-83 years (total n = 81) with Stage 0-II were treated with SF or HfB (Mobetron, IntraOp Medical, Sunnyvale, CA). For SF treatment, 21 Gy was delivered using 4.5-6 cm applicators with electron energies from 6 to 12 MeV. For HfB, an intraoperative boost of 10 Gy was delivered using 4-7 cm applicators with energies from 4 to 12 MeV followed by whole-breast radiation with 40.5 Gy over 15 fractions. Toxicity was assessed at 2 weeks, 6 months, and 12 months per Radiation Therapy Oncology Group acute skin toxicity criteria and cosmesis. At 12 months, SF and HfB were well tolerated by all patients with no Grade 3+ toxicity. At 1 year, Grade-2 toxicity was resolved. Ninety-eight percent of SF patients and ninety percent of HfB patients had 0-1 grade toxicity. In the SF and HfB groups, 100% of patients had excellent or good cosmesis at 12-month followup interval. The SF exhibited a more favorable cosmesis with a higher percentage of excellent scores compared with HfB (80.4% vs. 45%; p = 0.0033). After breast conservation surgery, SF or HfB may be an option for patients with early-stage breast cancer compared to conventional external beam radiotherapy. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  4. Short course radiotherapy with simultaneous integrated boost for stage I-II breast cancer, early toxicities of a randomized clinical trial

    Science.gov (United States)

    2012-01-01

    Background TomoBreast is a unicenter, non-blinded randomized trial comparing conventional radiotherapy (CR) vs. hypofractionated Tomotherapy (TT) for post-operative treatment of breast cancer. The purpose of the trial is to compare whether TT can reduce heart and pulmonary toxicity. We evaluate early toxicities. Methods The trial started inclusion in May 2007 and reached its recruitment in August 2011. Women with stage T1-3N0M0 or T1-2N1M0 breast cancer completely resected by tumorectomy (BCS) or by mastectomy (MA) who consented to participate were randomized, according to a prescribed computer-generated randomization schedule, between control arm of CR 25x2 Gy/5 weeks by tangential fields on breast/chest wall, plus supraclavicular-axillary field if node-positive, and sequential boost 8x2 Gy/2 weeks if BCS (cumulative dose 66 Gy/7 weeks), versus experimental TT arm of 15x2.8 Gy/3 weeks, including nodal areas if node-positive and simultaneous integrated boost of 0.6 Gy if BCS (cumulative dose 51 Gy/3 weeks). Outcomes evaluated were the pulmonary and heart function. Comparison of proportions used one-sided Fisher's exact test. Results By May 2010, 70 patients were randomized and had more than 1 year of follow-up. Out of 69 evaluable cases, 32 were assigned to CR (21 BCS, 11 MA), 37 to TT (20 BCS, 17 MA). Skin toxicity of grade ≥1 at 2 years was 60% in CR, vs. 30% in TT arm. Heart function showed no significant difference for left ventricular ejection fraction at 2 years, CR 4.8% vs. TT 4.6%. Pulmonary function tests at 2 years showed grade ≥1 decline of FEV1 in 21% of CR, vs. 15% of TT and decline of DLco in 29% of CR, vs. 7% of TT (P = 0.05). Conclusions There were no unexpected severe toxicities. Short course radiotherapy of the breast with simultaneous integrated boost over 3 weeks proved feasible without excess toxicities. Pulmonary tests showed a slight trend in favor of Tomotherapy, which will need confirmation with longer

  5. Treatment of patients with atypical meningiomas Simpson grade 4 and 5 with a carbon ion boost in combination with postoperative photon radiotherapy: The MARCIE Trial

    Directory of Open Access Journals (Sweden)

    Unterberg Andreas

    2010-11-01

    Full Text Available Abstract Background Treatment standard for patients with atypical or anaplastic meningioma is neurosurgical resection. With this approach, local control ranges between 50% and 70%, depending on resection status. A series or smaller studies has shown that postoperative radiotherapy in this patient population can increase progression-free survival, which translates into increased overall survival. However, meningiomas are known to be radioresistant tumors, and radiation doses of 60 Gy or higher have been shown to be necessary for tumor control. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE, which can be calculated between 2 and 5 depending on the cell line as well as the endpoint analyzed. First data obtained within the Phase I/II trial performed at GSI in Darmstadt on carbon ion radiotherapy for patients with high-risk meningiomas has shown safety, and treatment results are promising. Methods/design The Phase II-MARCIE-Study will evaluate a carbon ion boost applied to the macroscopic tumor in conjunction with photon radiotherapy in patients with atypical menigiomas after incomplete resection or biopsy. Primary endpoint is progression-free survival, secondary endpoints are overall survival, safety and toxicity. Discussion Based on published data on the treatment of atypical meningiomas with carbon ions at GSI, the present study will evaluate this treatment concept in a larger patient population and will compare outcome to current standard photon treatment. Trial registration NCT01166321

  6. Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor

    International Nuclear Information System (INIS)

    Shirato, Hiroki; Shimizu, Shinichi; Kitamura, Kei; Nishioka, Takeshi; Kagei, Kenji; Hashimoto, Seiko; Aoyama, Hidefumi; Kunieda, Tatsuya; Shinohara, Nobuo; Dosaka-Akita, Hirotoshi; Miyasaka, Kazuo

    2000-01-01

    Purpose: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice. Methods and Materials: We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second. The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter. Results: The coordinates of the marker were detected with an accuracy of ± 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a 'tight' planning target volume (PTV) margin. They were surviving without relapse or complications with a median follow-up of 6 months. Conclusion: Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors

  7. Early clinical outcome of coverage probability based treatment planning for simultaneous integrated boost of nodes in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Lindegaard, Jacob Chr; Assenholt, Marianne; Ramlov, Anne

    2017-01-01

    INTRODUCTION: More than 50% of patients with locally advanced cervical cancer (LACC) have pathological nodes. Coverage probability (CovP) is a new planning technique allowing for relaxed dose at the boost periphery minimising collateral irradiation. The aim was to report the first early clinical...... remission at 3 months is predictive for favourable long-term nodal control, our study indicates that CovP for SIB is promising....

  8. An in silico comparison between margin-based and probabilistic target-planning approaches in head and neck cancer patients

    NARCIS (Netherlands)

    Fontanarosa, Davide; van der Laan, Hans Paul; Witte, Marnix; Shakirin, Georgy; Roelofs, Erik; Langendijk, Johannes A.; Lambin, Philippe; van Herk, Marcel

    2013-01-01

    To apply target probabilistic planning (TPP) approach to intensity modulated radiotherapy (IMRT) plans for head and neck cancer (HNC) patients. Twenty plans of HNC patients were re-planned replacing the simultaneous integrated boost IMRT optimization objectives for minimum dose on the boost target

  9. [A Phase I/II Study of Chemotherapy Concurrent with Twice-daily Radiotherapy 
Schedules by Intensity Modulated Radiation Therapy Using Simultaneous Integrated Boost for Limited-stage Small Cell Lung Cancer].

    Science.gov (United States)

    You, Jing; Yu, Huiming; Song, Maxiaowei; Shi, Chen; Wang, Xiaohang; Zheng, Ye; Yu, Rong; Shi, Anhui; Zhu, Guangying

    2017-01-20

    Twice-daily radiation concurrent with chemotherapy is one of the standard methods for limited-stage small cell lung cancer. The study was to evaluate the feasibility of chemotherapy concurrent with dose-escalating twice-daily radiotherapy by simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) approach in patients with limited-stage small cell lung cancer. Patients with limited-stage small cell lung cancer were included, treated with twice-daily radiotherapy by SIB-IMRT concurrent with chemotherapy of etoposide plus cisplatin. Dose escalation was conducted by "classical" 3+3 methods with three patients enrolled in each dose level. The therapeutic gross tumor volume (GTV) was treated according to three consecutive dose levels i.e., 45 Gy at 1.5 Gy twice daily, 50 Gy at 1.67 Gy twice daily and 54 Gy at 1.8 Gy twice daily. The planning target volume (PTV) received a dose of 45 Gy delivered in 30 fractions of 1.5 Gy. The primary endpoints were acute toxicities. The secondary endpoints included overall survival (OS), progression-free survival (PFS) and loco-regional failure-free survival (LRFFS) at 1-year of follow-up. Twenty men and six women were included. The median age was 52 (30-68) months. 12 patients experienced grade 2 acute esophagitis, and 1 patient developed grade 3 acute esophagitis. Only 3 patients developed Grade 2 pneumonitis. Grade 3 or higher radiation-related pneumonia was not observed. None died of treatment-related causes. With median follow-up of 11.2 months (3.2-36.2 months), 1-year OS, PFS and LRFFS were 89.0%, 51.0% and 85.0%, respectively. Dose escalation for twice-daily radiation concurrent with chemotherapy in LS-SCLC has been safely achieved up to 54 Gy for GTV using SIB-IMRT technique.

  10. The functional imaging in target volume delineation of radiotherapy planning for gliomas

    International Nuclear Information System (INIS)

    Huang Jingxiong; Wu Hua

    2007-01-01

    Radiotherapy is one of important treatments for glioma. Functional imaging, such as PET, SPECT and MRI, may provide more valuable information not only in display of the evasion extent of glioma but also in demonstration of some biological characteristics of the tumor, such as perfusion, metabolism, hypoxia or proliferation. Thus it may play a role in making an individualized and more exact radiotherapy planning. (authors)

  11. Ranking radiotherapy treatment plans using decision-analytic and heuristic techniques.

    OpenAIRE

    Jain, N. L.; Kahn, M. G.

    1991-01-01

    Radiotherapy treatment optimization is done by generating a set of tentative treatment plans, evaluating them and selecting the plan closest to achieving a set of conflicting treatment objectives. The evaluation of potential plans involves making tradeoffs among competing possible outcomes. Multiattribute decision theory provides a framework for specifying such tradeoffs and using them to select optimal actions. Using these concepts, we have developed a plan-ranking model which ranks a set of...

  12. Full-thickness closure in breast-conserving surgery: the impact on radiotherapy target definition for boost and partial breast irradiation. A multimodality image evaluation.

    Science.gov (United States)

    den Hartogh, Mariska D; van den Bongard, H J G Desirée; Davidson, Melanie T M; Kotte, Alexis N T J; Verkooijen, Helena M; Philippens, Marielle E P; van Vulpen, Marco; van Asselen, Bram; Pignol, Jean-Philippe

    2014-11-01

    During breast-conserving surgery (BCS), surgeons increasingly perform full-thickness closure (FTC) to prevent seroma formation. This could potentially impair precision of target definition for boost and accelerated partial breast irradiation (APBI). The purpose of this study was to investigate the precision of target volume definition following BCS with FTC among radiation oncologists, using various imaging modalities. Twenty clinical T1-2N0 patients, scheduled for BCS involving clip placement and FTC, were included in the study. Seven experienced breast radiation oncologists contoured the tumor bed on computed tomography (CT), magnetic resonance imaging (MRI) and fused CT-MRI datasets. A total of 361 observer pairs per image modality were analyzed. A pairwise conformity among the generated contours of the observers and the distance between their centers of mass (dCOM) were calculated. On CT, median conformity was 44 % [interquartile range (IQR) 28-58 %] and median dCOM was 6 mm (IQR 3-9 mm). None of the outcome measures improved when MRI or fused CT-MRI were used. In two patients, superficial closure was performed instead of FTC. In these 14 image sets and 42 observer pairs, median conformity increased to 70 %. Localization of the radiotherapy target after FTC is imprecise, on both CT and MRI. This could potentially lead to a geographical miss in patients at increased risk of local recurrence receiving a radiation boost, or for those receiving APBI. These findings highlight the importance for breast surgeons to clearly demarcate the tumor bed when performing FTC.

  13. High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: unusual toxicity and promising early results

    International Nuclear Information System (INIS)

    King, Stephen C.; Acker, Jeffrey C.; Kussin, Peter S.; Marks, Lawrence B.; Weeks, Kenneth J.; Leopold, Kenneth A.

    1996-01-01

    Purpose: The treatment of nonsmall cell lung cancer (NSCLC) with conventional radiotherapy (RT) results in inadequate local tumor control and survival. We report results of a Phase II trial designed to treat patients with a significantly increased total dose administered in a reduced overall treatment time using a hyperfractionated, accelerated treatment schedule with a concurrent boost technique. Methods and Materials: A total of 49 patients with unresectable Stage IIIA/IIIB (38 patients) or medically inoperable Stage I/II (11 patients) NSCLC were prospectively enrolled in this protocol. Radiation therapy was administered twice daily, 5 days/week with > 6 h between each treatment. The primary tumor and adjacent enlarged lymph nodes were treated to a total dose of 73.6 Gy in 46 fractions of 1.6 Gy each. Using a concurrent boost technique, electively irradiated nodal regions were simultaneously treated with a dose of 1.25 Gy/fraction for the first 36 fractions to a total dose of 45 Gy. Results: Median survival for the entire group of 49 patients is 15.3 months. Actuarial survival at 2 years is 46%: 60% for 11 Stage I/II patients, 55% for 21 Stage IIIA patients, and 26% for 17 Stage IIIB patients. The actuarial rate of freedom from local progression at 2 years is 64% for the entire group of 49 patients: 62% for Stage I/II patients, 70% for Stage IIIA patients, and 55% for Stage IIIB patients. Patients who underwent serial bronchoscopic reevaluation (4 Stage I/II, 8 Stage IIIA, and 6 Stage IIIB) have an actuarial rate of local control of 71% at 2 years. The median total treatment time was 32 days. Nine of 49 patients (18%) experienced Grade III acute esophageal toxicity. The 2-year actuarial risk of Grade III or greater late toxicity is 30%. The 2-year actuarial rate of severe-late pulmonary and skin-subcutaneous toxicity is 20% and 15%, respectively. Conclusion: This treatment regimen administers a substantially higher biologically effective dose compared with

  14. The NUKDOS software for treatment planning in molecular radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kletting, Peter; Schimmel, Sebastian [Univ. Ulm (Germany). Klinik fuer Nuklearmedizin; Haenscheid, Heribert; Fernandez, Maria; Lassmann, Michael [Univ. Wuerzburg (Germany). Klinik fuer Nuklearmedizin; Luster, Markus [Univ. Marburg (Germany). Klinik fuer Nuklearmedizin; Nosske, Dietmar [Bundesamt fuer Strahlenschutz, Fachbereich Strahlenschutz und Gesundheit, Oberschleissheim (Germany); Glatting, Gerhard [Heidelberg Univ., Medical Radiation Physics/Radiation Protection, Mannheim (Germany)

    2015-07-01

    The aim of this work was the development of a software tool for treatment planning prior to molecular radiotherapy, which comprises all functionality to objectively determine the activity to administer and the pertaining absorbed doses (including the corresponding error) based on a series of gamma camera images and one SPECT/CT or probe data. NUKDOS was developed in MATLAB. The workflow is based on the MIRD formalism For determination of the tissue or organ pharmacokinetics, gamma camera images as well as probe, urine, serum and blood activity data can be processed. To estimate the time-integrated activity coefficients (TIAC), sums of exponentials are fitted to the time activity data and integrated analytically. To obtain the TIAC on the voxel level, the voxel activity distribution from the quantitative 3D SPECT/CT (or PET/CT) is used for scaling and weighting the TIAC derived from the 2D organ data. The voxel S-values are automatically calculated based on the voxel-size of the image and the therapeutic nuclide ({sup 90}Y, {sup 131}I or {sup 177}Lu). The absorbed dose coefficients are computed by convolution of the voxel TIAC and the voxel S-values. The activity to administer and the pertaining absorbed doses are determined by entering the absorbed dose for the organ at risk. The overall error of the calculated absorbed doses is determined by Gaussian error propagation. NUKDOS was tested for the operation systems Windows {sup registered} 7 (64 Bit) and 8 (64 Bit). The results of each working step were compared to commercially available (SAAMII, OLINDA/EXM) and in-house (UlmDOS) software. The application of the software is demonstrated using examples form peptide receptor radionuclide therapy (PRRT) and from radioiodine therapy of benign thyroid diseases. For the example from PRRT, the calculated activity to administer differed by 4% comparing NUKDOS and the final result using UlmDos, SAAMII and OLINDA/EXM sequentially. The absorbed dose for the spleen and tumour

  15. Intraoperative radiotherapy electron boost followed by moderate doses of external beam radiotherapy in resected soft-tissue sarcoma of the extremities

    International Nuclear Information System (INIS)

    Azinovic, Ignacio; Martinez Monge, Rafael; Aristu, Jose Javier; Salgado, Esteban; Villafranca, Elena; Hidalgo, Oscar Fernandez; Amillo, Santiago; San Julian, Miguel; Villas, Carlos; Aramendia, Jose Manuel; Calvo, Felipe A.

    2003-01-01

    Purpose: To analyze the patterns of failure and the toxicity profile of intraoperative electron beam radiotherapy (IOERT) after resection of soft tissue sarcomas of the extremities (STS). Patients and methods: Forty-five patients with extremity STS were treated with IOERT and moderate-dose postoperative radiotherapy (45-50 Gy). Twenty-six patients were treated for primary disease (PD) and 19 patients for an isolated recurrence (ILR). Tumor size was >5 cm (maximum diameter) in 36 patients (80%), and high-grade histology in PD patients was present in 14 patients (54%). In nine patients, IOERT was used alone, due to previous irradiation or patient refusal. Chemotherapy (neoadjuvant and/or adjuvant) was mainly given to high-grade tumors. Results: Nine patients relapsed in the extremity (20%), and 12 patients in distant sites (28%). Actuarial local control at 5 years was 88% for patients with negative/close margins and 57% for patients presenting positive margins (P=0.04). Five patients (11%) developed neuropathy associated with the treatment. Extremity preservation was achieved in 40 patients (88%). With a median follow-up of 93 months (range: 27-143 months) for the patients at risk, 25 patients remain alive (a 7-year actuarial survival rate of 75% for PD and 47% for ILR; P=0.01). Conclusions: IOERT combined with moderate doses of external beam irradiation yields high local control and extremity preservation rates in resected extremity STS. Peripheral nerves in the IOERT field are dose-limiting structures requiring a dose compromise in the IOERT component to avoid severe neurological damage

  16. Ultrasound scanning in planning radiotherapy in cervix uteri cancer stump

    International Nuclear Information System (INIS)

    Nazarova, I.S.; Demidova, L.V.

    1989-01-01

    Application of ultrasound scanning for topometric preparation of 63 patients with cervix uteri cancer stump enabled to visualize clearly cervix uteri stump in a small pelvis and determine exactly its sizes and cupola thickness in particular. This enabled to improve the technique of combined radiotherapy and achieve five-year survival rate equal to 76.9%

  17. SU-F-J-145: MRI-Guided Interventional Boost Radiotherapy for Rectal Cancer: Investigating the Feasibility of Adapting the Anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Kleijnen, J J E; Couwenberg, A M; Asselen, B van; Lagendijk, J J W; Intven, M; Raaymakers, B W [University Medical Center Utrecht, Utrecht, Utrecht (Netherlands)

    2016-06-15

    Purpose: The recent development of an MRI-linac allows adaptation of treatments to the anatomy of the moment. This anatomy, in turn, could be altered into a more favorable situation for radiotherapy purposes. The purpose of this study is to investigate the potential dosimetric benefits of manipulating rectal anatomy in MRI-guided interventional external-beam radiotherapy for rectal cancer. Methods: For this retrospective analysis, four patients (1M/3F) diagnosed with rectal cancer were included. These underwent MR-imaging using sonography transmission gel as endorectal contrast at time of diagnosis and standard, non-contrast, MR-imaging prior to radiotherapy planning. In the contrast scan, the rectum is inflated by the inserted contrast gel, thereby potentially increasing the distance between tumor and the organs-at-risk (OAR). Both anatomies were delineated and 7- beam IMRT-plans were calculated for both situations (RT-standard and RT-inflated), using in-house developed treatment planning software. Each plan was aimed to deliver 15Gy to the planning target volume (PTV; tumor+3mm margin) with a D99>95% and Dmax<120% of the planned dose. The D2cc dose to the OAR were then compared for both situations. Results: At equal (or better) target coverage, we found a mean reduction in D2cc of 4.1Gy/237% [range 2.6Gy–6.3Gy/70%–621%] for the bladder and of 2.0Gy/145% [range −0.7Gy–7.9Gy/−73%–442%] for the small-bowel, for the RT-inflated compared to the RT-standard plans. For the three female patients, a reduction in D2cc of 5.2Gy/191% [range 3.2Gy–9.2Gy/44%–475%] for the gynecological organs was found. We found all D2cc doses to be better for the RT-inflated plans, except for one patient for whom the bladder D2cc dose was slightly increased. Conclusion: Reduction of OAR dose by manipulation of anatomy is feasible. Inflation of the rectum results in more distance between OAR and PTV. This leads to a substantial reduction in dose to OAR at equal or better target

  18. Australasian Gastrointestinal Trials Group (AGITG) Contouring Atlas and Planning Guidelines for Intensity-Modulated Radiotherapy in Anal Cancer

    International Nuclear Information System (INIS)

    Ng, Michael; Leong, Trevor; Chander, Sarat; Chu, Julie; Kneebone, Andrew; Carroll, Susan; Wiltshire, Kirsty; Ngan, Samuel; Kachnic, Lisa

    2012-01-01

    Purpose: To develop a high-resolution target volume atlas with intensity-modulated radiotherapy (IMRT) planning guidelines for the conformal treatment of anal cancer. Methods and Materials: A draft contouring atlas and planning guidelines for anal cancer IMRT were prepared at the Australasian Gastrointestinal Trials Group (AGITG) annual meeting in September 2010. An expert panel of radiation oncologists contoured an anal cancer case to generate discussion on recommendations regarding target definition for gross disease, elective nodal volumes, and organs at risk (OARs). Clinical target volume (CTV) and planning target volume (PTV) margins, dose fractionation, and other IMRT-specific issues were also addressed. A steering committee produced the final consensus guidelines. Results: Detailed contouring and planning guidelines and a high-resolution atlas are provided. Gross tumor and elective target volumes are described and pictorially depicted. All elective regions should be routinely contoured for all disease stages, with the possible exception of the inguinal and high pelvic nodes for select, early-stage T1N0. A 20-mm CTV margin for the primary, 10- to 20-mm CTV margin for involved nodes and a 7-mm CTV margin for the elective pelvic nodal groups are recommended, while respecting anatomical boundaries. A 5- to 10-mm PTV margin is suggested. When using a simultaneous integrated boost technique, a dose of 54 Gy in 30 fractions to gross disease and 45 Gy to elective nodes with chemotherapy is appropriate. Guidelines are provided for OAR delineation. Conclusion: These consensus planning guidelines and high-resolution atlas complement the existing Radiation Therapy Oncology Group (RTOG) elective nodal ano-rectal atlas and provide additional anatomic, clinical, and technical instructions to guide radiation oncologists in the planning and delivery of IMRT for anal cancer.

  19. Australasian Gastrointestinal Trials Group (AGITG) Contouring Atlas and Planning Guidelines for Intensity-Modulated Radiotherapy in Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Michael, E-mail: mng@radoncvic.com.au [Radiation Oncology Victoria, Victoria (Australia); Leong, Trevor [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); University of Melbourne (Australia); Chander, Sarat; Chu, Julie [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); Kneebone, Andrew [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, NSW (Australia); University of Sydney (Australia); Carroll, Susan [Department of Radiation Oncology, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); University of Sydney (Australia); Wiltshire, Kirsty [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); Ngan, Samuel [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); University of Melbourne (Australia); Kachnic, Lisa [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States)

    2012-08-01

    Purpose: To develop a high-resolution target volume atlas with intensity-modulated radiotherapy (IMRT) planning guidelines for the conformal treatment of anal cancer. Methods and Materials: A draft contouring atlas and planning guidelines for anal cancer IMRT were prepared at the Australasian Gastrointestinal Trials Group (AGITG) annual meeting in September 2010. An expert panel of radiation oncologists contoured an anal cancer case to generate discussion on recommendations regarding target definition for gross disease, elective nodal volumes, and organs at risk (OARs). Clinical target volume (CTV) and planning target volume (PTV) margins, dose fractionation, and other IMRT-specific issues were also addressed. A steering committee produced the final consensus guidelines. Results: Detailed contouring and planning guidelines and a high-resolution atlas are provided. Gross tumor and elective target volumes are described and pictorially depicted. All elective regions should be routinely contoured for all disease stages, with the possible exception of the inguinal and high pelvic nodes for select, early-stage T1N0. A 20-mm CTV margin for the primary, 10- to 20-mm CTV margin for involved nodes and a 7-mm CTV margin for the elective pelvic nodal groups are recommended, while respecting anatomical boundaries. A 5- to 10-mm PTV margin is suggested. When using a simultaneous integrated boost technique, a dose of 54 Gy in 30 fractions to gross disease and 45 Gy to elective nodes with chemotherapy is appropriate. Guidelines are provided for OAR delineation. Conclusion: These consensus planning guidelines and high-resolution atlas complement the existing Radiation Therapy Oncology Group (RTOG) elective nodal ano-rectal atlas and provide additional anatomic, clinical, and technical instructions to guide radiation oncologists in the planning and delivery of IMRT for anal cancer.

  20. Recommendations for the use of PET and PET-CT for radiotherapy planning in research projects.

    Science.gov (United States)

    Somer, E J; Pike, L C; Marsden, P K

    2012-08-01

    With the increasing use of positron emission tomography (PET) for disease staging, follow-up and therapy monitoring in a number of oncological indications there is growing interest in the use of PET and PET-CT for radiation treatment planning. In order to create a strong clinical evidence base for this, it is important to ensure that research data are clinically relevant and of a high quality. Therefore the National Cancer Research Institute PET Research Network make these recommendations to assist investigators in the development of radiotherapy clinical trials involving the use of PET and PET-CT. These recommendations provide an overview of the current literature in this rapidly evolving field, including standards for PET in clinical trials, disease staging, volume delineation, intensity modulated radiotherapy and PET-augmented planning techniques, and are targeted at a general audience. We conclude with specific recommendations for the use of PET in radiotherapy planning in research projects.

  1. Phase II study of capecitabine (Xeloda (registered) ) and concomitant boost radiotherapy in patients with locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Krishnan, Sunil; Janjan, Nora A.; Skibber, John M.; Rodriguez-Bigas, Miguel A.; Wolff, Robert A.; Das, Prajnan; Delclos, Marc E.; Chang, George J.; Hoff, Paulo M.; Eng, Cathy; Brown, Thomas D.; Crane, Christopher H.; Feig, Barry W.; Morris, Jeffrey; Vadhan-Raj, Saroj; Hamilton, Stanley R.; Lin, Edward H.

    2006-01-01

    Purpose: The aim of this study was to determine the efficacy of capecitabine (Xeloda (registered) ), an oral fluoropyrimidine, as a radiosensitizer in the neoadjuvant treatment of locally advanced rectal cancer (LARC). Methods and Materials: We conducted a phase II study of capecitabine (825 mg/m 2 orally, twice daily continuous) with radiotherapy (52.5 Gy/30 fractions to the primary tumor and perirectal nodes) in 54 patients with LARC (node-negative ≥T3 or any node-positive tumor) staged by endoscopic ultrasound (EUS). The primary endpoint was pathologic response rate; secondary endpoints included toxicity profiles and survival parameters. Results: Of the 54 patients (median age, 56.7 years; range, 21.3-78.7 years; male:female ratio, 1.7; Eastern Cooperative Oncology Group performance status 0-1: 100%), 51 patients (94%) had T3N0 or T3N1 disease by EUS. Surgery was not performed in 3 patients; 2 of these patients had metastatic disease, and the third patient refused after a complete clinical response. Of the 51 patients evaluable for pathologic response, 9 patients (18%) achieved complete response, and 12 patients (24%) had microscopic residual disease (<10% viable cells). In addition, 26 patients of all 54 patients (51%) achieved T-downstaging, and 15 patients of 29 patients (52%) achieved N-downstaging. Grade 3/4 toxicities were radiation dermatitis (9%) and diarrhea (2%). Sphincter preservation rate for tumor ≤5 cm from the anal verge was 67% (18/27). Conclusion: This regimen of radiotherapy plus capecitabine is well tolerated and is more convenient than protracted venous infusion of 5-FU. The pathologic response rate is comparable to our previous experience using protracted venous infusion 5-FU for LARC

  2. Nonrigid Image Registration for Head and Neck Cancer Radiotherapy Treatment Planning With PET/CT

    International Nuclear Information System (INIS)

    Ireland, Rob H.; Dyker, Karen E.; Barber, David C.; Wood, Steven M.; Hanney, Michael B.; Tindale, Wendy B.; Woodhouse, Neil; Hoggard, Nigel; Conway, John; Robinson, Martin H.

    2007-01-01

    Purpose: Head and neck radiotherapy planning with positron emission tomography/computed tomography (PET/CT) requires the images to be reliably registered with treatment planning CT. Acquiring PET/CT in treatment position is problematic, and in practice for some patients it may be beneficial to use diagnostic PET/CT for radiotherapy planning. Therefore, the aim of this study was first to quantify the image registration accuracy of PET/CT to radiotherapy CT and, second, to assess whether PET/CT acquired in diagnostic position can be registered to planning CT. Methods and Materials: Positron emission tomography/CT acquired in diagnostic and treatment position for five patients with head and neck cancer was registered to radiotherapy planning CT using both rigid and nonrigid image registration. The root mean squared error for each method was calculated from a set of anatomic landmarks marked by four independent observers. Results: Nonrigid and rigid registration errors for treatment position PET/CT to planning CT were 2.77 ± 0.80 mm and 4.96 ± 2.38 mm, respectively, p = 0.001. Applying the nonrigid registration to diagnostic position PET/CT produced a more accurate match to the planning CT than rigid registration of treatment position PET/CT (3.20 ± 1.22 mm and 4.96 ± 2.38 mm, respectively, p = 0.012). Conclusions: Nonrigid registration provides a more accurate registration of head and neck PET/CT to treatment planning CT than rigid registration. In addition, nonrigid registration of PET/CT acquired with patients in a standardized, diagnostic position can provide images registered to planning CT with greater accuracy than a rigid registration of PET/CT images acquired in treatment position. This may allow greater flexibility in the timing of PET/CT for head and neck cancer patients due to undergo radiotherapy

  3. Intensity-modulated radiotherapy using simultaneous-integrated boost for definitive treatment of locally advanced mucosal head and neck cancer: outcomes from a single-institution series

    International Nuclear Information System (INIS)

    Johnston, Meredith; Guo, Linxin; Hanna, Catherine; Back, Michael; Guminski, Alex; Lee, Adrian; Eade, Thomas; Veivers, David; Wignall, Andrew

    2013-01-01

    The study aims to report outcomes for patients treated using intensity-modulated radiotherapy (IMRT) with simultaneous-integrated boost and weekly cisplatin for American Joint Committee on Cancer stage III/IV mucosal head and neck squamous cell carcinomas (HNSCCs). Records for 67 patients treated definitively with IMRT for HNSCC were reviewed. By including only those treated with weekly cisplatin, 45 patients were eligible for analysis. Treatment outcomes, effect of patient, tumour and treatment characteristics on disease recurrence were analysed. All patients completed IMRT to 7000cGy in 35 fractions, with concurrent weekly cisplatin 40mg/m 2 (median 6 cycles). Median follow-up was 28 months for living patients. Two-year loco-regional recurrence-free, metastasis-free and overall survival were 85.4, 81.0 and 87.4%, respectively. Local recurrence occurred in three patients, and distant recurrence in eight patients. Our results show efficacy of IMRT and weekly cisplatin in the treatment of stage III/IV HNSCC at our institution with respect to loco-regional control.

  4. IMRT, IGRT, SBRT - Advances in the Treatment Planning and Delivery of Radiotherapy

    CERN Document Server

    Meyer, JL

    2011-01-01

    Over the last 4 years, IMRT, IGRT, SBRT: Advances in the Treatment Planning and Delivery of Radiotherapy has become a standard reference in the field. During this time, however, significant progress in high-precision technologies for the planning and delivery of radiotherapy in cancer treatment has called for a second edition to include these new developments. Thoroughly updated and extended, this new edition offers a comprehensive guide and overview of these new technologies and the many clinical treatment programs that bring them into practical use. Advances in intensity-modulated radiothera

  5. Inter-observer agreement of MRI-based tumor delineation for preoperative radiotherapy boost in locally advanced rectal cancer.

    Science.gov (United States)

    Burbach, Johannes Peter Maarten; Kleijnen, Jean-Paul Johannes; Reerink, Onne; Seravalli, Enrica; Philippens, Marielle E P; Schakel, Tim; van Asselen, Bram; Raaymakers, Bas W; van Vulpen, Marco; Intven, Martijn

    2016-02-01

    While surgery remains the cornerstone of rectal cancer treatment, organ-preservation is upcoming. Therefore, neo-adjuvant treatment should be optimized. By escalating doses, response can be increased. To limit toxicity of boost, accurate gross tumor volume (GTV) definition is required. MRI, especially undeformed fast spin echo diffusion-weighted MRI (DWI), looks promising for delineation. However, inconsistencies between observers should be quantified before clinical implementation. We aim to find which MRI sequence (T2w, DWI or combination) is optimal and clinically useful for GTV definition by evaluating inter-observer agreement. Locally advanced rectal cancer patients (tumors 0.61). Average HD was largest on T2 (18.60mm, max 31.40 mm, min 9.20mm). Delineation on DWI resulted in delineation of the smallest volumes with similar consistency and mean distances, but with slightly lower Hausdorff distances compared to T2 and Combi. However, with lack of a gold standard it remains difficult to establish if delineations also represent true tumor. Study strengths were DWI adaptation to exclude geometrical distortions and training-set. DWI shows great potential for delineation purposes as long as sufficient experience exists and geometrical distortions are eliminated. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Moderate hypofractionated radiotherapy with volumetric modulated arc therapy and simultaneous integrated boost for pelvic irradiation in prostate cancer.

    Science.gov (United States)

    Franzese, C; Fogliata, A; D'Agostino, G R; Di Brina, L; Comito, T; Navarria, P; Cozzi, L; Scorsetti, M

    2017-07-01

    The optimal treatment for unfavourable intermediate/high-risk prostate cancer is still debated. In the present study, the pattern of toxicity and early clinical outcome of patients with localized prostate cancer was analyzed. A cohort of 90 patients treated on pelvic lymph nodes from 2010 to 2015 was selected. All patients were treated with Volumetric Modulated Arc Therapy (VMAT), and Simultaneous integrated boost (SIB) in 28 fractions; the prostate, the seminal vesicle and the pelvic lymph node received total doses of 74.2, 65.5, and 51.8 Gy, respectively. End points were the detection of acute and late toxicities graded according to the Common Toxicity Criteria CTCAE version 3, evaluating the rectal, genito-urinary and gastro-intestinal toxicity. Correlation of OARs dose parameters and related toxicities was explored. Preliminary overall survival and Progression-free survival (PFS) were evaluated. With a median follow-up of 25 months, no interruptions for treatment-related toxicity were recorded. Univariate analysis among dosimetric data and acute toxicities showed no correlations. Regarding late toxicity: the dose received by a rectal volume of 90 cm 3 was found to be significant for toxicity prediction (p = 0.024). PFS was 90.6% and 60.2% at 2 and 4 years, respectively. PFS correlates with age (p = 0.011) and Gleason score (p = 0.011). Stratifying the PSA nadir in quartiles, its value was significant (p = 0.016) in predicting PFS, showing a reduction of PFS of 2 months for each PSA-nadir increase of 0.1 ng/ml. HRT with VMAT and SIB on the whole pelvis in unfavourable prostate cancer patients is effective with a mild pattern of toxicity.

  7. Evaluation of isocenter reproducibility in telemedicine of 3D-radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Hirota, Saeko; Tsujino, Kayoko; Kimura, Kouji; Takada, Yoshiki; Hishikawa, Yoshio; Kono, Michio; Soejima, Toshinori; Kodama, Akihisa

    2000-01-01

    To evaluate the utility in telemedicine of Three-Dimensional Radiotherapy Treatment Planning (tele-3D-RTP) and to examine the accuracy of isocenter reproducibility in its offline trial. CT data of phantoms and patients in the satellite hospital were transferred to our hospital via floppy-disk and 3D-radiotherapy plans were generated by 3D-RTP computer in our hospital. Profile data of CT and treatment beams in the satellite hospital were pre-installed into the computer. Tele-3D-RTPs were performed in 3 phantom plans and 14 clinical plans for 13 patients. Planned isocenters were well reproduced, especially in the immobilized head and neck/brain tumor cases, whose 3D-vector of aberration was 1.96±1.38 (SD) mm. This teletherapy system is well applicable for practical use and can provides cost-reduction through sharing the resources of expensive equipment and radiation oncologists. (author)

  8. Comparative treatment planning study on sequential vs. simultaneous integrated boost in head and neck cancer patients. Differences in dose distributions and potential implications for clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Stromberger, Carmen; Ghadjar, Pirus; Marnitz, Simone; Thieme, Alexander Henry; Jahn, Ulrich; Karaj-Rossbacher, Evis; Budach, Volker [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology and Radiotherapy, Berlin (Germany); Raguse, Jan D. [Charite Universitaetsmedizin Berlin, Clinic for Oral and Maxillofacial Surgery, Berlin (Germany); Boettcher, Arne [Charite Universitaetsmedizin Berlin, Otorhinolaryngology, Berlin (Germany); Jamil, Basil [Communal Hospital Frankfurt Oder, Department of Radiation Oncology, Frankfurt/Oder (Germany)

    2016-01-15

    The purpose of this work was to compare sequential (SeqB) versus simultaneous integrated boost (SIB) radiotherapy plans delivered with volumetric modulated arc therapy (VMAT) for patients with locally advanced squamous cell cancer of the head and neck (HNSCC). SeqB and SIB plans using VMAT for 10 HNSCC patients given definitive chemoradiation were generated and analysed for differences in dose distribution, coverage, conformity and homogeneity to the planning target volumes (PTV) 1-3 and sparing of organs at risk (OAR). The mean delineated volumes ± standard deviations were 137.7 ± 44.8, 351.3 ± 83.9 and 895.6 ± 120.5 cm{sup 3} for PTV1-3. The mean volumes encompassed by the corresponding 95 % isodoses were 281 (+ 110 %) ± 73.4, 712.2 (+ 115 %) ± 146.4 and 1381.1 (+ 54 %) ± 217.3 cm{sup 3} with SeqB and 138.2 (+ 7 %) ± 40.1, 380.4 (+ 11 %) ± 91.9 and 1057.3 (+ 21 %) ± 161.4 cm{sup 3} with SIB for PTV1-3, respectively. Both strategies achieved excellent PTV coverage. SeqB provided significantly better coverage of PTV1 and 3, worse conformity for PTV1-3 and a higher mean dose than prescribed (111-115 %) to PTV2 and 3 (p ≤ 0.007). Both strategies provided satisfactory OAR sparing. This study showed significant dosimetric differences with potential clinical relevance between two VMAT boost strategies regarding coverage, conformity and dose to the PTVs. SIB might cause less toxicity. A clinical phase III/IV trial endorsed by the German Head and Neck Clinical Trials Group (IAG-KHT) will evaluate differences in acute/late toxicity as well as in locoregional recurrences between the two boost techniques. (orig.) [German] Vergleich von sequentiellem (SeqB) und simultan-integriertem Boost (SIB) mit moderner volumetrischer Arc-Therapie (VMAT) fuer Patienten mit Plattenepithelkarzinomen der Kopf-Hals-Region. Fuer 10 Patienten mit Plattenepithelkarzinomen der Kopf-Hals-Region und definitiver Radiochemotherapie erfolgte eine VMAT-Planung als SeqB und SIB fuer die

  9. Clinical treatment planning for stereotactic radiotherapy, evaluation by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Kairn, T.; Aland, T.; Kenny, J.; Knight, R.T.; Crowe, S.B.; Langton, C.M.; Franich, R.D.; Johnston, P.N.

    2010-01-01

    Full text: This study uses re-evaluates the doses delivered by a series of clinical stereotactic radiotherapy treatments, to test the accuracy of treatment planning predictions for very small radiation fields. Stereotactic radiotherapy treatment plans for meningiomas near the petrous temporal bone and the foramen magnum (incorp rating fields smaller than I c m2) were examined using Monte Carlo simulations. Important differences between treatment planning predictions and Monte Carlo calculations of doses delivered to stereotactic radiotherapy patients are apparent. For example, in one case the Monte Carlo calculation shows that the delivery a planned meningioma treatment would spare the patient's critical structures (eyes, brainstem) more effectively than the treatment plan predicted, and therefore suggests that this patient could safely receive an increased dose to their tumour. Monte Carlo simulations can be used to test the dose predictions made by a conventional treatment planning system, for dosimetrically challenging small fields, and can thereby suggest valuable modifications to clinical treatment plans. This research was funded by the Wesley Research Institute, Australia. The authors wish to thank Andrew Fielding and David Schlect for valuable discussions of aspects of this work. The authors are also grateful to Muhammad Kakakhel, for assisting with the design and calibration of our linear accelerator model, and to the stereotactic radiation therapy team at Premion, who designed the treatment plans. Computational resources and services used in this work were provided by the HPC and Research Support Unit, QUT, Brisbane, Australia. (author)

  10. Paediatric Photon and Proton Radiotherapy Treatment Planning Based on Advanced Imaging

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.

    affecting the cancer cells, the treatment regimen often leads to undesired damage in healthy tissue and these treatment-induced side effects may impair the function of vital organs. The severity of the injury can range from potentially lethal to being rather easily managed with regular follow...... radiotherapy treatment planning in combination with the nuclear medicine imaging technique positron emission tomography (PET). Specifically, we investigate the potential impact on the radiotherapy treatment plans of modern radiotherapy modalities for paediatric and adolescent cancer patients, when adding...... survival of the patients and due to the increased risk of secondary cancers following the increased radiation dose. In this context, radiation oncology experts must critically assess whether the use of PET is of benefit to the patients. The low number of paediatric cancer patients and the considerable...

  11. Radiotherapy

    International Nuclear Information System (INIS)

    Pistenma, D.A.

    1980-01-01

    The need for radiotherapy research is exemplified by the 100,000 cancer patients who will fail treatment locally and/or regionally annually for the next several years but who would benefit from better local treatment modalities. Theoretically, all of the areas of investigation discussed in this projection paper have the potential to significantly improve local-regional treatment of cancer by radiotherapy alone or in combination with other modalities. In many of the areas of investigation discussed in this paper encouraging results have been obtained in cellular and animal tumor studies and in limited studies in humans as well. In the not too distant future the number of patients who would benefit from better local control may increase by tens of thousands if developments in chemotherapy and/or immunotherapy provide a means to eradicate disseminated microscopic foci of cancer. Thus the efforts to improve local-regional control take on even greater significance

  12. External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor

    2005-01-01

    Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

  13. Evaluation of delivered dose for a clinical daily adaptive plan selection strategy for bladder cancer radiotherapy

    NARCIS (Netherlands)

    Lutkenhaus, Lotte J.; Visser, Jorrit; de Jong, Rianne; Hulshof, Maarten C. C. M.; Bel, Arjan

    2015-01-01

    To account for variable bladder size during bladder cancer radiotherapy, a daily plan selection strategy was implemented. The aim of this study was to calculate the actually delivered dose using an adaptive strategy, compared to a non-adaptive approach. Ten patients were treated to the bladder and

  14. T(3) LARYNGEAL-CANCER, PRIMARY SURGERY VS PLANNED COMBINED RADIOTHERAPY AND SURGERY

    NARCIS (Netherlands)

    TJHOHESLINGA, RE; TERHAARD, CHJ; SCHOUWENBURG, P; HILGERS, FJM; DOLSMA, WV; CROLL, GA; HOOGENHOUT, J; KNEGT, PP; LEER, JWH; HORDIJK, GJ

    1993-01-01

    The Dutch Co-operative Head and Neck Oncology Group performed a retrospective, nationwide study of laryngeal cancer between 1975 and 1984. The results for T3 laryngeal cancer treated with primary laryngectomy (n = 137) with post-operative radiotherapy when indicated or planned combined

  15. 3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

    International Nuclear Information System (INIS)

    Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

    2005-01-01

    Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

  16. A New Brain Positron Emission Tomography Scanner With Semiconductor Detectors for Target Volume Delineation and Radiotherapy Treatment Planning in Patients With Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Norio, E-mail: noriwokatoh@med.hokudai.ac.jp [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Yasuda, Koichi [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Shiga, Tohru [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Bengua, Gerard; Ishikawa, Masayori [Department of Medical Physics, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Tamaki, Nagara [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Shirato, Hiroki [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

    2012-03-15

    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET{sub CONV}WB) versus the new brain (BR) PET system using semiconductor detectors (PET{sub NEW}BR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [{sup 18}F]Fluorodeoxyglucose-PET images were acquired using both the PET{sub NEW}BR and the PET{sub CONV}WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET{sub CONV}WB and PET{sub NEW}BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET{sub CONV}WB (GTV{sub CONV}) images or PET{sub NEW}BR (GTV{sub NEW}) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume ({+-}standard deviation [SD]) of GTV{sub NEW} was 15.7 ml ({+-}9.9) ml, and that of GTV{sub CONV} was 34.0 ({+-}20.5) ml. The average GTV{sub NEW} was significantly smaller than that of GTV{sub CONV} (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN{sub NEW}) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy

  17. A new brain positron emission tomography scanner with semiconductor detectors for target volume delineation and radiotherapy treatment planning in patients with nasopharyngeal carcinoma.

    Science.gov (United States)

    Katoh, Norio; Yasuda, Koichi; Shiga, Tohru; Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi; Bengua, Gerard; Ishikawa, Masayori; Tamaki, Nagara; Shirato, Hiroki

    2012-03-15

    We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET(CONV)WB) versus the new brain (BR) PET system using semiconductor detectors (PET(NEW)BR). Twelve patients with NPC were enrolled in this study. [(18)F]Fluorodeoxyglucose-PET images were acquired using both the PET(NEW)BR and the PET(CONV)WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET(CONV)WB and PET(NEW)BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET(CONV)WB (GTV(CONV)) images or PET(NEW)BR (GTV(NEW)) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. The average absolute volume (±standard deviation [SD]) of GTV(NEW) was 15.7 ml (±9.9) ml, and that of GTV(CONV) was 34.0 (±20.5) ml. The average GTV(NEW) was significantly smaller than that of GTV(CONV) (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN(NEW)) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy treatment planning. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Treatment Planning Study to Determine Potential Benefit of Intensity-Modulated Radiotherapy Versus Conformal Radiotherapy for Unresectable Hepatic Malignancies

    International Nuclear Information System (INIS)

    Eccles, Cynthia L.; Bissonnette, Jean-Pierre; Craig, Tim; Taremi, Mojgan; Wu Xia; Dawson, Laura A.

    2008-01-01

    Purpose: To compare intensity-modulated radiotherapy (IMRT) with conformal RT (CRT) for hypofractionated isotoxicity liver RT and explore dose escalation using IMRT for the same/improved nominal risk of liver toxicity in a treatment planning study. Methods and Materials: A total of 26 CRT plans were evaluated. Prescription doses (24-54 Gy within six fractions) were individualized on the basis of the effective liver volume irradiated maintaining ≤5% risk of radiation-induced liver disease. The dose constraints included bowel (0.5 cm 3 ) and stomach (0.5 cm 3 ) to ≤30 Gy, spinal cord to ≤25 Gy, and planning target volume (PTV) to ≤140% of the prescribed dose. Two groups were evaluated: (1) PTV overlapping or directly adjacent to serial functioning normal tissues (n = 14), and (2) the liver as the dose-limiting normal tissue (n = 12). IMRT plans using direct machine parameter optimization maintained the CRT plan beam arrangements, an estimated radiation-induced liver disease risk of 5%, and underwent dose escalation, if all normal tissue constraints were maintained. Results: IMRT improved PTV coverage in 19 of 26 plans (73%). Dose escalation was feasible in 9 cases by an average of 3.8 Gy (range, 0.6-13.2) in six fractions. Three of seven plans without improved PTV coverage had small gross tumor volumes (≤105 cm 3 ) already receiving 54 Gy, the maximal prescription dose allowed. In the remaining cases, the PTV range was 9.6-689 cm 3 ; two had overlapped organs at risk; and one had four targets. IMRT did not improve these plans owing to poor target coverage (n = 2) and nonliver (n = 2) dose limits. Conclusion: Direct machine parameter optimization IMRT improved PTV coverage while maintaining normal tissue tolerances in most CRT liver plans. Dose escalation was possible in a minority of patients

  19. 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

  20. A semi-analytical radiobiological model may assist treatment planning in light ion radiotherapy

    Czech Academy of Sciences Publication Activity Database

    Kundrát, Pavel

    2007-01-01

    Roč. 52, č. 23 (2007), s. 6813-6830 ISSN 0031-9155 R&D Projects: GA ČR GA202/05/2728 Institutional research plan: CEZ:AV0Z10100502 Keywords : Bragg peak * light ions * hadron * hadron radiotherapy * biological effectiveness * treatment planning Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.528, year: 2007

  1. Intensity-Modulated Radiotherapy with a Simultaneous Integrated Boost Combined with Chemotherapy in Stages III-IV Hypopharynx-Larynx Cancer: Treatment Compliance and Clinical Outcomes

    International Nuclear Information System (INIS)

    Franchin, G.; Gobitti, C.; Minatel, E.; Furlan, C.; Trovo, M.G.; Vaccher, E.; Talamini, R.; Grando, G.; Barzan, L.; Drigo, A.

    2014-01-01

    Objectives. Retrospective review of our experience using intensity-modulated radiotherapy with simultaneous integrated boost (SIB-IMRT) combined with chemotherapy as the primary treatment of locoregionally advanced larynx and hypopharynx cancers. Materials and Methods. Between September 2008 and June 2012, 60 patients (26 with larynx and 34 hypopharynx cancers) were treated. Our policy was to offer SIB-IMRT plus concurrent cisplatin to patients affected by larynx cancer stage T3N0-N1 and NCT with TPF (docetaxel/cisplatin/fluorouracil) followed by SIB-IMRT to patients with larynx cancer stage T2-4N2-3 or hypopharynx cancer T2-4N0-3. SIB-IMRT consisted in a total dose of 70.95 Gy (2.15 Gy/fraction, 5 fractions/week) to the gross primary and nodal disease and differentiated dosages for high risk and low risk nodal regions. Results. Complete remission was achieved in 53/60 (88%) of patients. At a median follow up of 31 months (range 9–67), the rate of overall survival and locoregional control with functional larynx at 3 years were 68% and 60%, respectively. T stage (T1–3 versus T4) resulted in being significant for predicting 3-year freedom from relapse (it was 69% and 35%, resp., for T1–T3 and T4 tumors; (Ρ =0.35),while site of primary disease (larynx versus hypopharynx) was not significant (Ρ =0.35). Conclusion. Our results indicated that combining SIB-IMRT with induction chemotherapy or concurrent chemotherapy is an effective treatment strategy for organ preservation in advanced larynx/hypopharynx cancer.

  2. IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB technique

    Directory of Open Access Journals (Sweden)

    Benassi Marcello

    2011-05-01

    Full Text Available Abstract Background An advantage of the Intensity Modulated Radiotherapy (IMRT technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED, i.e. IsoBED, compared to the standard fractionation. Methods Based on the Linear Quadratic Model (LQM, we developed software that allows treatment schedules, biologically equivalent to standard fractionations, to be calculated. The main radiobiological parameters from literature are included in a database inside the software, which can be updated according to the clinical experience of each Institute. In particular, the BED to each target volume will be computed based on the alpha/beta ratio, total dose and the dose per fraction (generally 2 Gy for a standard fractionation. Then, after selecting the reference target, i.e. the PTV that controls the fractionation, a new total dose and dose per fraction providing the same isoBED will be calculated for each target volume. Results The IsoBED Software developed allows: 1 the calculation of new IsoBED treatment schedules derived from standard prescriptions and based on LQM, 2 the conversion of the dose-volume histograms (DVHs for each Target and OAR to a nominal standard dose at 2Gy per fraction in order to be shown together with the DV-constraints from literature, based on the LQM and radiobiological parameters, and 3 the calculation of Tumor Control Probability (TCP and Normal Tissue Complication Probability (NTCP curve versus the prescribed dose to the reference target.

  3. Stereotactic body radiotherapy with a focal boost to the MRI-visible tumor as monotherapy for low- and intermediate-risk prostate cancer: early results

    International Nuclear Information System (INIS)

    Aluwini, Shafak; Rooij, Peter van; Hoogeman, Mischa; Kirkels, Wim; Kolkman-Deurloo, Inger-Karine; Bangma, Chris

    2013-01-01

    There is growing evidence that prostate cancer (PC) cells are more sensitive to high fraction dose in hypofractionation schemes. High-dose-rate (HDR) brachytherapy as monotherapy is established to be a good treatment option for PC using extremely hypofractionated schemes. This hypofractionation can also be achieved with stereotactic body radiotherapy (SBRT). We report results on toxicity, PSA response, and quality of life (QOL) in patients treated with SBRT for favorable-risk PC. Over the last 4 years, 50 hormone-naïve patients with low- and intermediate-risk PC were treated with SBRT to a total dose of 38 Gy delivered in four daily fractions of 9.5 Gy. An integrated boost to 11 Gy per fraction was applied to the dominant lesion if visible on MRI. Toxicity and QoL was assessed prospectively using validated questionnaires. Median follow-up was 23 months. The 2-year actuarial biochemical control rate was 100%. Median PSA nadir was 0.6 ng/ml. Median International Prostate Symptoms Score (IPSS) was 9/35 before treatment, with a median increase of 4 at 3 months and remaining stable at 13/35 thereafter. The EORTC/RTOG toxicity scales showed grade 2 and 3 gastrointestinal (GI) acute toxicity in 12% and 2%, respectively. The late grade 2 GI toxicity was 3% during 24 months FU. Genitourinary (GU) grade 2, 3 toxicity was seen in 15%, 8%, in the acute phase and 10%, 6% at 24 months, respectively. The urinary, bowel and sexual domains of the EORTC-PR25 scales recovered over time, showing no significant changes at 24 months post-treatment. SBRT to 38 Gy in 4 daily fractions for low- and intermediate-risk PC patients is feasible with low acute and late genitourinary and gastrointestinal toxicity. Longer follow-up preferably within randomized studies, is required to compare these results with standard fractionation schemes

  4. Validation of Fully Automated VMAT Plan Generation for Library-Based Plan-of-the-Day Cervical Cancer Radiotherapy.

    Science.gov (United States)

    Sharfo, Abdul Wahab M; Breedveld, Sebastiaan; Voet, Peter W J; Heijkoop, Sabrina T; Mens, Jan-Willem M; Hoogeman, Mischa S; Heijmen, Ben J M

    2016-01-01

    To develop and validate fully automated generation of VMAT plan-libraries for plan-of-the-day adaptive radiotherapy in locally-advanced cervical cancer. Our framework for fully automated treatment plan generation (Erasmus-iCycle) was adapted to create dual-arc VMAT treatment plan libraries for cervical cancer patients. For each of 34 patients, automatically generated VMAT plans (autoVMAT) were compared to manually generated, clinically delivered 9-beam IMRT plans (CLINICAL), and to dual-arc VMAT plans generated manually by an expert planner (manVMAT). Furthermore, all plans were benchmarked against 20-beam equi-angular IMRT plans (autoIMRT). For all plans, a PTV coverage of 99.5% by at least 95% of the prescribed dose (46 Gy) had the highest planning priority, followed by minimization of V45Gy for small bowel (SB). Other OARs considered were bladder, rectum, and sigmoid. All plans had a highly similar PTV coverage, within the clinical constraints (above). After plan normalizations for exactly equal median PTV doses in corresponding plans, all evaluated OAR parameters in autoVMAT plans were on average lower than in the CLINICAL plans with an average reduction in SB V45Gy of 34.6% (plibraries has become feasible.

  5. Computer-aided isodose planning in radiotherapy of cancer of uterus. I

    International Nuclear Information System (INIS)

    Matula, P.; Futas, E.; Kunstadt, E.; Kazar, A.; Klvana, M.; Rexova, J.

    1981-01-01

    In this first part of the report on the specification of dose distribution in radiotherapy of the cancer of the uterus the authors are concerned with the location of radiophores in gynecologic loading using their own applicators of the system of manual afterloading. They recommend the stereometric location system as most suitable for routine clinical practice. This method using a common portable X-ray device, is described in the report together with the algorithm for calculating the spatial coordinates of the radiophores. The algorithm is a subprogram of a computer program for planning isodoses in the complex radiotherapy of the cancer of the uterus. (author)

  6. An approach to contouring the dorsal vagal complex for radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    O' Steen, Lillie; Amdur, Robert J., E-mail: amdurr@shands.ufl.edu

    2016-04-01

    Multiple studies suggest that radiation dose to the area of the brainstem called the “dorsal vagal complex (DVC)” influences the frequency of nausea and vomiting during radiotherapy. The purpose of this didactic article is to describe the step-by-step process that we use to contour the general area of the DVC on axial computed tomography (CT) images as would be done for radiotherapy planning. The contouring procedure that we describe for contouring the area of the DVC is useful to medical dosimetrists and radiation oncologists.

  7. Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

    DEFF Research Database (Denmark)

    Pommer, T.; Falk, Marianne; Poulsen, Per Rugaard

    2013-01-01

    This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose...... during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average...

  8. Development of applicable software containing radiobiological and physical indices to evaluate radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seu Ran; Suh, Tae Suk [Dept. of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Park, Ji Yeon [Molecular Imaging Program at Stanford, Stafnord University, Richmond (United States)

    2014-11-15

    Adaptive radiation therapy (ART) provides more conformal dose distribution to the morphologically and physiologically changed tumor volumes during fractionated radiation therapy (RT). To develop an enhanced treatment plan evaluation tool based on multi-modality imaging which incorporates physical and radiobiological parameters, the software system was developed using MATLAB v.7.10.0499 (The Mathworks, Inc., Natick, MA). The application of plan evaluation can help the user choose more biologically optimal treatment plans and potentially predict treatment outcome more accurately. The radiotherapy planning based on the multi-modality images had more accurate results than that of based on only CT images in both physical and radiobiological perspectives.

  9. Quality assessment for VMAT prostate radiotherapy planning based on data envelopment analysis

    International Nuclear Information System (INIS)

    Lin, Kuan-Min; Simpson, John; Raith, Andrea; Ehrgott, Matthias; Sasso, Giuseppe

    2013-01-01

    The majority of commercial radiotherapy treatment planning systems requires planners to iteratively adjust the plan parameters in order to find a satisfactory plan. This iterative trial-and-error nature of radiotherapy treatment planning results in an inefficient planning process and in order to reduce such inefficiency, plans can be accepted without achieving the best attainable quality. We propose a quality assessment method based on data envelopment analysis (DEA) to address this inefficiency. This method compares a plan of interest to a set of past delivered plans and searches for evidence of potential further improvement. With the assistance of DEA, planners will be able to make informed decisions on whether further planning is required and ensure that a plan is only accepted when the plan quality is close to the best attainable one. We apply the DEA method to 37 prostate plans using two assessment parameters: rectal generalized equivalent uniform dose (gEUD) as the input and D95 (the minimum dose that is received by 95% volume of a structure) of the planning target volume (PTV) as the output. The percentage volume of rectum overlapping PTV is used to account for anatomical variations between patients and is included in the model as a non-discretionary output variable. Five plans that are considered of lesser quality by DEA are re-optimized with the goal to further improve rectal sparing. After re-optimization, all five plans improve in rectal gEUD without clinically considerable deterioration of the PTV D95 value. For the five re-optimized plans, the rectal gEUD is reduced by an average of 1.84 Gray (Gy) with only an average reduction of 0.07 Gy in PTV D95. The results demonstrate that DEA can correctly identify plans with potential improvements in terms of the chosen input and outputs. (paper)

  10. Radiographer-led breast boost localisation – A service evaluation study

    International Nuclear Information System (INIS)

    Smith, S.; Comins, C.

    2015-01-01

    A radiation boost to the tumour bed as part of breast conserving therapy reduces the rate of local recurrence. Radiographer-led planning for tangential field radiotherapy has been the practice at our centre since 2007. The transition from conventional simulation to computed tomography (CT) and virtual simulation enhanced the radiographer's role in the breast planning process. Electron boost mark ups continued to be marked up freehand by doctors using available imaging to determine tumour bed. The paper reports on a service evaluation undertaken to establish a change in practice for electron breast boosts to be simulated using the virtual simulator by suitably trained radiographers. The retrospective simulation of ten patients confirmed the consistency of radiographer tumour bed localisation, followed by the prospective simulation of ten patients' boost fields. The introduction of a radiographer-led planning breast boost service has given greater autonomy and job satisfaction to individuals as well as resulting in a cost effective use of available resources. - Highlights: • A service evaluation study was undertaken to train a radiographer to perform breast boost planning. • Retrospective breast boost planning established proposed technique was workable. • Prospective planning by radiographer proved their competence. • Introduction of new technique provided job satisfaction and service improvement

  11. Patient-specific dosimetric endpoints based treatment plan quality control in radiotherapy

    International Nuclear Information System (INIS)

    Song, Ting; Zhou, Linghong; Staub, David; Chen, Mingli; Lu, Weiguo; Tian, Zhen; Jia, Xun; Li, Yongbao; Jiang, Steve B; Gu, Xuejun

    2015-01-01

    In intensity modulated radiotherapy (IMRT), the optimal plan for each patient is specific due to unique patient anatomy. To achieve such a plan, patient-specific dosimetric goals reflecting each patient’s unique anatomy should be defined and adopted in the treatment planning procedure for plan quality control. This study is to develop such a personalized treatment plan quality control tool by predicting patient-specific dosimetric endpoints (DEs). The incorporation of patient specific DEs is realized by a multi-OAR geometry-dosimetry model, capable of predicting optimal DEs based on the individual patient’s geometry. The overall quality of a treatment plan is then judged with a numerical treatment plan quality indicator and characterized as optimal or suboptimal. Taking advantage of clinically available prostate volumetric modulated arc therapy (VMAT) treatment plans, we built and evaluated our proposed plan quality control tool. Using our developed tool, six of twenty evaluated plans were identified as sub-optimal plans. After plan re-optimization, these suboptimal plans achieved better OAR dose sparing without sacrificing the PTV coverage, and the dosimetric endpoints of the re-optimized plans agreed well with the model predicted values, which validate the predictability of the proposed tool. In conclusion, the developed tool is able to accurately predict optimally achievable DEs of multiple OARs, identify suboptimal plans, and guide plan optimization. It is a useful tool for achieving patient-specific treatment plan quality control. (paper)

  12. A Phase I/II Study of Chemotherapy Concurrent with Twice-daily Radiotherapy 
Schedules by Intensity Modulated Radiation Therapy Using Simultaneous Integrated Boost for Limited-stage Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Jing YOU

    2017-01-01

    Full Text Available Background and objective Twice-daily radiation concurrent with chemotherapy is one of the standard methods for limited-stage small cell lung cancer. The study was to evaluate the feasibility of chemotherapy concurrent with dose-escalating twice-daily radiotherapy by simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT approach in patients with limited-stage small cell lung cancer. Methods Patients with limited-stage small cell lung cancer were included, treated with twice-daily radiotherapy by SIB-IMRT concurrent with chemotherapy of etoposide plus cisplatin. Dose escalation was conducted by “classical” 3+3 methods with three patients enrolled in each dose level. The therapeutic gross tumor volume (GTV was treated according to three consecutive dose levels i.e., 45 Gy at 1.5 Gy twice daily, 50 Gy at 1.67 Gy twice daily and 54 Gy at 1.8 Gy twice daily. The planning target volume (PTV received a dose of 45 Gy delivered in 30 fractions of 1.5 Gy. The primary endpoints were acute toxicities. The secondary endpoints included overall survival (OS, progression-free survival (PFS and loco-regional failure-free survival (LRFFS at 1-year of follow-up. Results Twenty men and six women were included. The median age was 52 (30-68 months. 12 patients experienced grade 2 acute esophagitis, and 1 patient developed grade 3 acute esophagitis. Only 3 patients developed Grade 2 pneumonitis. Grade 3 or higher radiation-related pneumonia was not observed. None died of treatment-related causes. With median follow-up of 11.2 months (3.2-36.2 months, 1-year OS, PFS and LRFFS were 89.0%, 51.0% and 85.0%, respectively. Conclusion Dose escalation for twice-daily radiation concurrent with chemotherapy in LS-SCLC has been safely achieved up to 54 Gy for GTV using SIB-IMRT technique.

  13. PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning

    DEFF Research Database (Denmark)

    Sattler, Bernhard; Lee, John A; Lonsdale, Markus

    2010-01-01

    , especially when transferring data across the (network-) borders of different hospitals. Overall, the most important precondition for successful integration of functional imaging in RT treatment planning is the goal orientated as well as close and thorough communication between nuclear medicine......The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non......-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy...

  14. Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning

    Science.gov (United States)

    Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.

    2017-09-01

    To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving  ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving  ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p  =  0.04) and 0.2% (range: 0 to 4.1%; p  =  0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.

  15. Radiotherapy

    International Nuclear Information System (INIS)

    Hubert, D.

    2009-01-01

    Context: the descendants of persons treated for a childhood cancer could have an increased risk of genetic disease because of mutagenic anti cancerous treatments received by their parents. 3963 survivors of cancer in childhood ( born between 12950 and 1984) have been identified from the Danish register of cancer, constituting the 'survivors' cohort. 5657 of their brothers and sisters constituting the 'siblings' cohort have been identified from the Danish central register of the population. All of the live-born children born from these two cohorts have been identified from this register, allowing to include 1715 descendants from the 'survivors' cohort and 6009 descendants from the 'siblings' cohort. The congenital malformations have been found out from the national hospital register. The irradiation doses to the gonads and uterus have been defined by using the usual radiotherapy protocols. Conclusion: This study shows that the anti cancerous treatments for children do not seem increase the risk of congenital malformations in their progeny. (N.C.)

  16. Radiotherapy treatment planning using three dimensional CT images

    International Nuclear Information System (INIS)

    Araki, Yutaka; Isobe, Yoshihide; Ozaki, Shin; Hosoki, Takuya; Mori, Shigeru; Ikeda, Hiroshi.

    1984-01-01

    Recently superimposition of dose distribution onto CT images has become available with the use of planning computers. However, the distribution is mostly along the plane of central axis of the beam, and evaluation of the quality of planning has not been established yet. It cannot be concluded whether the planning is suitable or not, even if the dose distribution at a certain CT slice seems to be optimum. The need has been emerged to compare the treatment planning quantitatively with other ones. A computerized treatment planning system has been developed in our hospital, which can accumulate voxel dose of each lattice point, can superimpose isodose curves on multiple transverse contours, and can construct and display a 3-dimensional image of the treatment region using a ''cutting method''. In this paper, a method is proposed to evaluate the quality of treatment planning, introducing the definitions in ICRU report 29 and using the 3-dimensional computer algorism. Concepts and procedures are described in detail with some case examples. (author)

  17. A DVH-guided IMRT optimization algorithm for automatic treatment planning and adaptive radiotherapy replanning

    International Nuclear Information System (INIS)

    Zarepisheh, Masoud; Li, Nan; Long, Troy; Romeijn, H. Edwin; Tian, Zhen; Jia, Xun; Jiang, Steve B.

    2014-01-01

    Purpose: To develop a novel algorithm that incorporates prior treatment knowledge into intensity modulated radiation therapy optimization to facilitate automatic treatment planning and adaptive radiotherapy (ART) replanning. Methods: The algorithm automatically creates a treatment plan guided by the DVH curves of a reference plan that contains information on the clinician-approved dose-volume trade-offs among different targets/organs and among different portions of a DVH curve for an organ. In ART, the reference plan is the initial plan for the same patient, while for automatic treatment planning the reference plan is selected from a library of clinically approved and delivered plans of previously treated patients with similar medical conditions and geometry. The proposed algorithm employs a voxel-based optimization model and navigates the large voxel-based Pareto surface. The voxel weights are iteratively adjusted to approach a plan that is similar to the reference plan in terms of the DVHs. If the reference plan is feasible but not Pareto optimal, the algorithm generates a Pareto optimal plan with the DVHs better than the reference ones. If the reference plan is too restricting for the new geometry, the algorithm generates a Pareto plan with DVHs close to the reference ones. In both cases, the new plans have similar DVH trade-offs as the reference plans. Results: The algorithm was tested using three patient cases and found to be able to automatically adjust the voxel-weighting factors in order to generate a Pareto plan with similar DVH trade-offs as the reference plan. The algorithm has also been implemented on a GPU for high efficiency. Conclusions: A novel prior-knowledge-based optimization algorithm has been developed that automatically adjust the voxel weights and generate a clinical optimal plan at high efficiency. It is found that the new algorithm can significantly improve the plan quality and planning efficiency in ART replanning and automatic treatment

  18. A clinical distance measure for evaluating treatment plan quality difference with Pareto fronts in radiotherapy

    Directory of Open Access Journals (Sweden)

    Kristoffer Petersson

    2017-07-01

    Full Text Available We present a clinical distance measure for Pareto front evaluation studies in radiotherapy, which we show strongly correlates (r = 0.74 and 0.90 with clinical plan quality evaluation. For five prostate cases, sub-optimal treatment plans located at a clinical distance value of >0.32 (0.28–0.35 from fronts of Pareto optimal plans, were assessed to be of lower plan quality by our (12 observers (p < .05. In conclusion, the clinical distance measure can be used to determine if the difference between a front and a given plan (or between different fronts corresponds to a clinically significant plan quality difference.

  19. Modeling of a planning system in radiotherapy and Nuclear Medicine using the MCNP6 code

    International Nuclear Information System (INIS)

    Massicano, Felipe

    2015-01-01

    Cancer therapy has many branches and one of them is the use of radiation sources as treatment leading method. Radiotherapy and nuclear medicine are examples of these treatment types. For using the ionization radiation as main tool for the therapy, there is the need of crafting many treatment simulation in order to maximum the tumoral tissue dose without surpass the dose limit in health tissue surrounding. Treatment planning systems (TPS) are systems which have the purpose of simulating these therapy types. Nuclear medicine and radiotherapy have many distinct features linked to the therapy mode and consequently they have different TPS destined for each. The radiotherapy TPS is more developed than the nuclear medicine TPS and by that reason the development of a TPS that was similar to the radiotherapy TPS, but enough generic for include other therapy types, it will contribute with significant advances in nuclear medicine and in others therapy types with radiation. Based on this, the goal of work was to model a TPS that utilizes the Monte Carlo N-Particle Transport code (MCNP6) in order to simulate radiotherapy therapy, nuclear medicine therapy and with potential for simulating other therapy types too. The result of this work was the creation of a Framework in Java language, object oriented, named IBMC which will assist in the development of new TPS with MCNP6 code. The IBMC allowed to develop rapidly and easily TPS for radiotherapy and nuclear medicine and the results were validated with systems already consolidated. The IBMC showed high potential for developing TPS by new therapy types. (author)

  20. The brachytherapy vaginal cuff boost in patients with cervix cancer IB1-IB2 that have been treated with surgery plus pelvic radiotherapy in ION SOLCA, Guayaquil Ecuador from November 1 to October 2002

    International Nuclear Information System (INIS)

    Gamboa, Eugenia; Falquez, Roberto

    2003-01-01

    To determine if the additional vaginal cuff irradiation is necessary or not in patients with cervix cancer, stages IB 1- IB 2, that has been treated previously with radical hysterectomies and pelvic radiotherapy, to get better local control and global survival versus presence of complications. We studied 54 patients from Radiation Oncology Department of ION SOLCA Guayaquil Ecuador, with cervix cancer stages IB1 - IB2, that have been treated with surgery plus pelvic radiotherapy plus or not brachytherapy. They have been divides into two arms, group one included surgery plus Rx T (radiotherapy) plus BxT (Brachytherapy), and group two included those patients with surgery plus external RxT alone. We studied, aged, histologic type, surgery type, doses and techniques of teletherapy and brachytherapy and we analyzed the presence of complications. Conclusions: The brachytherapy vaginal cuff boost in patients with cervix cancer IB1-IB2 that have been treated with surgery plus pelvic radiotherapy is not useful to get better local control and global survival in some patients carefully chosen without desfavorable factors, because this therapy represent and increase in the complication. (The author)

  1. A new concept for interactive radiotherapy planning with multicriteria optimization: first clinical evaluation.

    Science.gov (United States)

    Thieke, Christian; Küfer, Karl-Heinz; Monz, Michael; Scherrer, Alexander; Alonso, Fernando; Oelfke, Uwe; Huber, Peter E; Debus, Jürgen; Bortfeld, Thomas

    2007-11-01

    Currently, inverse planning for intensity-modulated radiotherapy (IMRT) can be a time-consuming trial and error process. This is because many planning objectives are inherently contradictory and cannot reach their individual optimum all at the same time. Therefore in clinical practice the potential of IMRT cannot be fully exploited for all patients. Multicriteria (multiobjective) optimization combined with interactive plan navigation is a promising approach to overcome these problems. We developed a new inverse planning system called "Multicriteria Interactive Radiotherapy Assistant (MIRA)". The optimization result is a database of patient specific, Pareto-optimal plan proposals. The database is explored with an intuitive user interface that utilizes both a new interactive element for plan navigation and familiar dose visualizations in form of DVH and isodose projections. Two clinical test cases, one paraspinal meningioma case and one prostate case, were optimized using MIRA and compared with the clinically approved planning program KonRad. Generating the databases required no user interaction and took approx. 2-3h per case. The interactive exploration required only a few minutes until the best plan was identified, resulting in a significant reduction of human planning time. The achievable plan quality was comparable to KonRad with the additional benefit of having plan alternatives at hand to perform a sensitivity analysis or to decide for a different clinical compromise. The MIRA system provides a complete database and interactive exploration of the solution space in real time. Hence, it is ideally suited for the inherently multicriterial problem of inverse IMRT treatment planning.

  2. A new concept for interactive radiotherapy planning with multicriteria optimization: First clinical evaluation

    International Nuclear Information System (INIS)

    Thieke, Christian; Kuefer, Karl-Heinz; Monz, Michael; Scherrer, Alexander; Alonso, Fernando; Oelfke, Uwe; Huber, Peter E.; Debus, Juergen; Bortfeld, Thomas

    2007-01-01

    Background and purpose: Currently, inverse planning for intensity-modulated radiotherapy (IMRT) can be a time-consuming trial and error process. This is because many planning objectives are inherently contradictory and cannot reach their individual optimum all at the same time. Therefore in clinical practice the potential of IMRT cannot be fully exploited for all patients. Multicriteria (multiobjective) optimization combined with interactive plan navigation is a promising approach to overcome these problems. Patients and methods: We developed a new inverse planning system called 'Multicriteria Interactive Radiotherapy Assistant (MIRA)'. The optimization result is a database of patient specific, Pareto-optimal plan proposals. The database is explored with an intuitive user interface that utilizes both a new interactive element for plan navigation and familiar dose visualizations in form of DVH and isodose projections. Two clinical test cases, one paraspinal meningioma case and one prostate case, were optimized using MIRA and compared with the clinically approved planning program KonRad. Results: Generating the databases required no user interaction and took approx. 2-3 h per case. The interactive exploration required only a few minutes until the best plan was identified, resulting in a significant reduction of human planning time. The achievable plan quality was comparable to KonRad with the additional benefit of having plan alternatives at hand to perform a sensitivity analysis or to decide for a different clinical compromise. Conclusions: The MIRA system provides a complete database and interactive exploration of the solution space in real time. Hence, it is ideally suited for the inherently multicriterial problem of inverse IMRT treatment planning

  3. Dosimetric comparison of vaginal vault ovoid brachytherapy versus intensity-modulated radiation therapy plans in postoperative patients of cervical carcinoma following whole pelvic radiotherapy

    Directory of Open Access Journals (Sweden)

    Divya Khosla

    2014-01-01

    Full Text Available Introduction: Dosimetric study to compare high dose rate (HDR vaginal vault ovoid brachytherapy plan versus intensity-modulated radiation therapy (IMRT boost plan for doses delivered to target volume and organs at risk (OAR in postoperative patients of cervical carcinoma following whole pelvic radiotherapy (WPRT. Materials and Methods: Fifteen postoperative patients of cervical carcinoma suitable for vaginal ovoid brachytherapy following WPRT of 46 Gy/23 fractions/4.5 weeks were included. All were treated with brachytherapy (two sessions of 8.5 Gy each. The equivalent dose for IMRT was calculated by computing biologically effective dose of brachytherapy by linear quadratic model. Dose of brachytherapy (two sessions of 8.5 Gy was equivalent to IMRT dose of 26 Gy/13 fractions. Doses to target volume and OAR were compared between HDR and IMRT plans. Results: Target volume was well covered with both HDR and IMRT plans, but dose with brachytherapy was much higher (P < 0.05. Mean doses, doses to 0.1, 1, 2, and 5cc, 1/3 rd , 1/2, and 2/3 rd volume of bladder and rectum were significantly lower with HDR plans. Conclusion: In postoperative patients of cervical carcinoma, HDR brachytherapy following WPRT appears to be better than IMRT for tumor coverage and reducing dose to critical organs.

  4. Operations research for resource planning and -use in radiotherapy: a literature review

    OpenAIRE

    Vieira, Bruno; Hans, Erwin W.; van Vliet-Vroegindeweij, Corine; van de Kamer, Jeroen; van Harten, Wim

    2016-01-01

    Background The delivery of radiotherapy (RT) involves the use of rather expensive resources and multi-disciplinary staff. As the number of cancer patients receiving RT increases, timely delivery becomes increasingly difficult due to the complexities related to, among others, variable patient inflow, complex patient routing, and the joint planning of multiple resources. Operations research (OR) methods have been successfully applied to solve many logistics problems through the development of a...

  5. A simple percutaneous inserter for radiopaque gold seeds used in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Hay, K.D.; Hindley, A.; Sharp, I.

    1998-01-01

    Percutaneous insertion of a radiopaque marker is an important technique used in radiotherapy planning for both external-beam and brachytherapy. It is of particular importance in the oral cavity. We describe the construction and use of a simple inserter for 'cold' gold seeds manufactured from a commercialiy available Becton Dickinson Brand 5-mL disposable syrinqe and a Becton Dickinson Brand 18 G 11/2 TW (1.25 x 38 mm) hypodermic needle. Copyright (1998) Blackwell Science Pty Ltd

  6. A case study of radiotherapy planning for a bilateral metal hip prosthesis prostate cancer patient

    International Nuclear Information System (INIS)

    Su, Andy; Reft, Chester; Rash, Carla; Price, Jennifer; Jani, Ashesh B.

    2005-01-01

    The purpose of this report is to communicate the observed advantage of intensity-modulated radiotherapy (IMRT) in a patient with bilateral metallic hip prostheses. In this patient with early-stage low-risk disease, a dose of 74 Gy was planned in two phases-an initial 50 Gy to the prostate and seminal vesicles and an additional 24 Gy to the prostate alone. Each coplanar beam avoided the prosthesis in the beam's eye view. Using the same target expansions for each phase, IMRT and 3D-conformal radiotherapy (CRT) plans were compared for target coverage and inhomogeneity as well as dose to the bladder and rectum. The results of the analysis demonstrated that IMRT provided superior target coverage with reduced dose to normal tissues for both individual phases of the treatment plan as well as for the composite treatment plan. The dose to the rectum was significantly reduced with the IMRT technique, with a composite V80 of 35% for the IMRT plan versus 70% for 3D-CRT plan. Similarly, the dose to the bladder was significantly reduced with a V80 of 9% versus 20%. Overall, various dosimetric parameters revealed the corresponding 3D-CRT plan would not have been acceptable. The results indicate significant success with IMRT in a clinical scenario where there were no curative alternatives for local treatment other than external beam radiotherapy. Therefore, definitive external beam radiation of prostate cancer patients with bilateral prosthesis is made feasible with IMRT. The work described herein may also have applicability to other groups of patients, such as those with gynecological or other pelvic malignancies

  7. Process Evaluation of the Boost-A™ Transition Planning Program for Adolescents on the Autism Spectrum: A Strengths-Based Approach

    Science.gov (United States)

    Hatfield, Megan; Falkmer, Marita; Falkmer, Torbjörn; Ciccarelli, Marina

    2018-01-01

    A process evaluation was conducted to determine the effectiveness, usability, and barriers and facilitators related to the Better OutcOmes & Successful Transitions for Autism (BOOST-A™), an online transition planning program. Adolescents on the autism spectrum (n = 33) and their parents (n = 39) provided feedback via an online questionnaire.…

  8. Contribution of PET–CT in radiotherapy planning of oesophageal carcinoma: A review

    International Nuclear Information System (INIS)

    Cheung, Gabriel Sai Man

    2013-01-01

    Purpose: The aim of this study was to systematically review published data on the efficacy of positron emission tomography–computed tomography (PET–CT) in the radiotherapy planning process of patients with oesophageal carcinoma. Methods: A systematic search of the PubMed, CINAHL, Cochrane Library and ScienceDirect databases was performed. The quality of the included studies was appraised using validated assessment tool. Data of the studies were synthesized, compared and evaluated by constructing evidentiary tables. Results: The 37 included studies, comprising a total sample size of 1921 patients, had moderate methodological quality. Overall primary tumour detection rate was 92.7%, and pooling estimate of specificity was 88% (95%CI: 83–91%) for local lymph node metastasis. The pooled studies presented heterogeneity for sensitivity (p < 0.01). The introduction of PET–CT to the radiotherapy planning process has facilitated target volume delineation. A standardized uptake value (SUV) of 2.5 could be used in supplementation to visual assessment by a qualified practitioner. Conclusions: PET–CT has a high specificity but due to its variable sensitivity, information from other clinical investigations should still be sought. Discretion and sound clinical judgment must also be exercised before using the biologic information for radiotherapy planning

  9. Treatment of breast cancer with simultaneous integrated boost in hybrid plan technique. Influence of flattening filter-free beams

    Energy Technology Data Exchange (ETDEWEB)

    Bahrainy, Marzieh; Kretschmer, Matthias; Joest, Vincent; Kasch, Astrid; Wuerschmidt, Florian; Dahle, Joerg; Lorenzen, Joern [Radiologische Allianz, Hamburg (Germany)

    2016-05-15

    The present study compares in silico treatment plans using hybrid plan technique during hypofractionated radiation of mammary carcinoma with simultaneous integrated boost (SIB). The influence of 6 MV photon radiation in flattening filter free (FFF) mode against the clinical standard flattening filter (FF) mode is to be examined. RT planning took place with FF and FFF radiation plans for 10 left-sided breast cancer patients. Hybrid plans were realised with two tangential IMRT fields and one VMAT field. The dose prescription was in line with the guidelines in the ARO-2010-01 study. The dosimetric verification took place with a manufacturer-independent measurement system. Required dose prescriptions for the planning target volumes (PTV) were achieved for both groups. The average dose values of the ipsi- and contralateral lung and the heart did not differ significantly. The overall average incidental dose to the left anterior descending artery (LAD) of 8.24 ± 3.9 Gy in the FFF group and 9.05 ± 3.7 Gy in the FF group (p < 0.05) were found. The dosimetric verifications corresponded to the clinical requirements. FFF-based RT plans reduced the average treatment time by 17 s/fraction. In comparison to the FF-based hybrid plan technique the FFF mode allows further reduction of the average LAD dose for comparable target volume coverage without adverse low-dose exposure of contralateral structures. The combination of hybrid plan technique and 6 MV photon radiation in the FFF mode is suitable for use with hypofractionated dose schemes. The increased dose rate allows a substantial reduction of treatment time and thus beneficial application of the deep inspiration breath hold technique. (orig.) [German] Vergleich der ''In-silico''-Bestrahlungsplaene der klinisch etablierten Hybridplan-Technik bei hypofraktionierter Bestrahlung des Mammakarzinoms mit simultan integriertem Boost (SIB). Untersucht wird der Einfluss von 6MV-Photonenstrahlung im Flattening

  10. Optimization in radiotherapy treatment planning thanks to a fast dose calculation method

    International Nuclear Information System (INIS)

    Yang, Mingchao

    2014-01-01

    This thesis deals with the radiotherapy treatments planning issue which need a fast and reliable treatment planning system (TPS). The TPS is composed of a dose calculation algorithm and an optimization method. The objective is to design a plan to deliver the dose to the tumor while preserving the surrounding healthy and sensitive tissues. The treatment planning aims to determine the best suited radiation parameters for each patient's treatment. In this thesis, the parameters of treatment with IMRT (Intensity modulated radiation therapy) are the beam angle and the beam intensity. The objective function is multi-criteria with linear constraints. The main objective of this thesis is to demonstrate the feasibility of a treatment planning optimization method based on a fast dose-calculation technique developed by (Blanpain, 2009). This technique proposes to compute the dose by segmenting the patient's phantom into homogeneous meshes. The dose computation is divided into two steps. The first step impacts the meshes: projections and weights are set according to physical and geometrical criteria. The second step impacts the voxels: the dose is computed by evaluating the functions previously associated to their mesh. A reformulation of this technique makes possible to solve the optimization problem by the gradient descent algorithm. The main advantage of this method is that the beam angle parameters could be optimized continuously in 3 dimensions. The obtained results in this thesis offer many opportunities in the field of radiotherapy treatment planning optimization. (author) [fr

  11. Treatment planning for heavy ion radiotherapy: calculation and optimization of biologically effective dose

    International Nuclear Information System (INIS)

    Kraemer, M.; Scholz, M.

    2000-09-01

    We describe a novel approach to treatment planning for heavy ion radiotherapy based on the local effect model (LEM) which allows to calculate the biologically effective dose not only for the target region but for the entire irradiation volume. LEM is ideally suited to be used as an integral part of treatment planning code systems for active dose shaping devices like the GSI raster scan system. Thus, it has been incorporated into our standard treatment planning system for ion therapy (TRiP). Single intensity modulated fields can be optimized with respect to homogeneous biologically effective dose. The relative biological effectiveness (RBE) is calculated separately for each voxel of the patient CT. Our radiobiologically oriented code system is in use since 1995 for the planning of irradiation experiments with cell cultures and animals such as rats and minipigs. Since 1997 it is in regular and successful use for patient treatment planning. (orig.)

  12. A comparison of conventional 'forward planning' with inverse planning for 3D conformal radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Oldham, Mark; Neal, Anthony; Webb, Steve

    1995-01-01

    A radiotherapy treatment plan optimisation algorithm has been applied to 48 prostate plans and the results compared with those of an experienced human planner. Twelve patients were used in the study, and 3-, 4-, 6- and 8-field plans (with standard coplanar beam angles for each plan type) were optimised by both the human planner and the optimisation algorithm. The human planner 'optimised' the plan by conventional forward planning techniques. The optimisation algorithm was based on fast simulated annealing using a cost-function designed to achieve a homogenous dose in the 'planning-target-volume' and to minimise the integral dose to the organs at risk. 'Importance factors' assigned to different regions of the patient provide a method for controlling the algorithm, and it was found that the same values gave good results for almost all plans. A study of the convergence of the algorithm is presented and optimal convergence parameters are determined. The plans were compared on the basis of both dose statistics and 'normal-tissue-complication-probability' (NTCP) and 'tumour-control-probability' (TCP). The results of the comparison study show that the optimisation algorithm yielded results that were at least as good as the human planner for all plan types, and on the whole slightly better. A study of the beam-weights chosen by the optimisation algorithm and the planner revealed differences that increased with the number of beams in the plan. The planner was found to make small perturbations about a conceived optimal beam-weight set. The optimisation algorithm showed much greater variation, in response to individual patient geometry, frequently deselecting certain beams altogether from the plan. The algorithm is shown to be a useful tool for radiotherapy treatment planning. For simple (e.g., three-field) plans it was found to consistently achieve slightly higher TCP and lower NTCP values. For more complicated (e.g., eight-field) plans the optimisation also achieved

  13. A review of plan library approaches in adaptive radiotherapy of bladder cancer.

    Science.gov (United States)

    Collins, Shane D; Leech, Michelle M

    2018-05-01

    Large variations in the shape and size of the bladder volume are commonly observed in bladder cancer radiotherapy (RT). The clinical target volume (CTV) is therefore frequently inadequately treated and large isotropic margins are inappropriate in terms of dose to organs at risk (OAR); thereby making adaptive radiotherapy (ART) attractive for this tumour site. There are various methods of ART delivery, however, for bladder cancer, plan libraries are frequently used. A review of published studies on plan libraries for bladder cancer using four databases (Pubmed, Science Direct, Embase and Cochrane Library) was conducted. The endpoints selected were accuracy and feasibility of initiation of a plan library strategy into a RT department. Twenty-four articles were included in this review. The majority of studies reported improvement in accuracy with 10 studies showing an improvement in planning target volume (PTV) and CTV coverage with plan libraries, some by up to 24%. Seventeen studies showed a dose reduction to OARs, particularly the small bowel V45Gy, V40Gy, V30Gy and V10Gy, and the rectal V30Gy. However, the occurrence of no suitable plan was reported in six studies, with three studies showing no significant difference between adaptive and non-adaptive strategies in terms of target coverage. In addition, inter-observer variability in plan selection appears to remain problematic. The additional resources, education and technology required for the initiation of plan library selection for bladder cancer may hinder its routine clinical implementation, with eight studies illustrating increased treatment time required. While there is a growing body of evidence in support of plan libraries for bladder RT, many studies differed in their delivery approach. The advent of the clinical use of the MRI-linear accelerator will provide RT departments with the opportunity to consider daily online adaption for bladder cancer as an alternate to plan library approaches.

  14. Interobserver Variability in Radiotherapy Plan Output: Results of a Single-Institution Study

    Science.gov (United States)

    Berry, Sean L; Boczkowski, Amanda; Ma, Rongtao; Mechalakos, James; Hunt, Margie

    2016-01-01

    Purpose To investigate the sources of variability in radiotherapy treatment plan output between planners within a single institution. Materials/Methods 40 treatment planners across 5 campuses of the same institution created a plan on copies of the same thoracic esophagus patient CT and structure set. Plans were scored and ranked based on the planner’s adherence to ordered list of target dose coverage and normal tissue evaluation criteria. A runs test was used to identify whether any of the studied planner qualities influenced the ranking. Spearman’s rank correlation was used to investigate whether plan score correlated with years of experience or planned MU. Results The distribution of scores, ranging from 80.24 to 135.89, was negatively skewed (mean = 128.7, median = 131.5). No statistically significant relationship between plan score and campus (p=0.193), job title (p=0.174), previous outside experience (p=0.611), or number of gantry angles (p=0.156) exists. No statistical correlation between plan score and MU or years of experience was found. Conclusion Despite clear and established critical organ dose criteria and well documented planning guidelines, planning variation still occurs, even among members of the same institution. As plan consistency does not seem to significantly correlate with experience, career path, or campus, investigation into alternate methods beyond additional education and training to reduce this variation, such as knowledge based planning or advanced optimization techniques, is necessary. PMID:27374191

  15. Automatic image segmentation for treatment planning in radiotherapy; Segmentation automatique des images pour la planifi cation dosimetrique en radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Pasquiera, D. [Centre Galilee, polyclinique de la Louviere, 59 - Lille (France); Peyrodie, L. [Ecole des hautes etudes d' ingenieur, 59 - Lille (France); Laboratoire d' automatique, genie informatique et signal (LAGIS), Cite scientifi que, 59 - Villeneuve d' Ascq (France); Denis, F. [Centre Jean-Bernard, 72 - Le Mans (France); Pointreau, Y.; Bera, G. [Clinique d' oncologie radiotherapie, Centre Henry-S.-Kaplan, CHU Bretonneau, 37 - Tours (France); Lartigau, E. [Departement universitaire de radiotherapie, Centre O. Lambret, Universite Lille 2, 59 - Lille (France)

    2010-07-01

    One drawback of the growth in conformal radiotherapy and image-guided radiotherapy is the increased time needed to define the volumes of interest. This also results in inter- and intra-observer variability. However, developments in computing and image processing have enabled these tasks to be partially or totally automated. This article will provide a detailed description of the main principles of image segmentation in radiotherapy, its applications and the most recent results in a clinical context. (authors)

  16. Implementation of an Analytical Model for Leakage Neutron Equivalent Dose in a Proton Radiotherapy Planning System

    Directory of Open Access Journals (Sweden)

    John Eley

    2015-03-01

    Full Text Available Equivalent dose from neutrons produced during proton radiotherapy increases the predicted risk of radiogenic late effects. However, out-of-field neutron dose is not taken into account by commercial proton radiotherapy treatment planning systems. The purpose of this study was to demonstrate the feasibility of implementing an analytical model to calculate leakage neutron equivalent dose in a treatment planning system. Passive scattering proton treatment plans were created for a water phantom and for a patient. For both the phantom and patient, the neutron equivalent doses were small but non-negligible and extended far beyond the therapeutic field. The time required for neutron equivalent dose calculation was 1.6 times longer than that required for proton dose calculation, with a total calculation time of less than 1 h on one processor for both treatment plans. Our results demonstrate that it is feasible to predict neutron equivalent dose distributions using an analytical dose algorithm for individual patients with irregular surfaces and internal tissue heterogeneities. Eventually, personalized estimates of neutron equivalent dose to organs far from the treatment field may guide clinicians to create treatment plans that reduce the risk of late effects.

  17. To analyze the impact of intracavitary brachytherapy as boost radiation after external beam radiotherapy in carcinoma of the external auditory canal and middle ear: A retrospective analysis

    Directory of Open Access Journals (Sweden)

    Dinesh K Badakh

    2014-01-01

    Conclusion: ICBT as a boost after EBRT has got a positive impact on the OS. In conclusion, our results demonstrate that radical radiation therapy (EBRT and ICBT is the treatment of choice for stage T2, carcinoma of EACMA.

  18. Planning and verification in radiotherapy: our experience in a filmless hospital

    International Nuclear Information System (INIS)

    Torresin, A.; Carbonini, C.; Ferrari, M.B.; Asnaghi, D.; Botturi, M.

    2009-01-01

    In our hospital we have recently installed a new radiotherapy treatment planning and verification system. Our system allows to follow the normal clinical work flow: from patient identification to follow-up through the treatment delivery with the study of the best irradiation geometry. We designed a new technical solutions relating to the use of four linear accelerators, a Record and Verify system, a Treatment Planning System (TPS) and a clinical folder, completely paperless. All the procedures for treatment planning, setup and verification are integrated in our digital imaging long-term archive. The integration is based on the existing HL7 and DICOM standard protocols described in the International Committee and IHE RO Technical Framework, which is able to support the work flow. All the images used for planning and setup are stored in the Oncentra DICOM archive server for short-term archiving and then are sent to the Agfa DICOM long-term archive for legal and scientific purposes. (authors)

  19. How precise is manual CT-MRI registration for cranial radiotherapy planning?

    International Nuclear Information System (INIS)

    Mosleh-Shirazi, M. A.; South, P. C.

    2005-01-01

    Manual fusion is a readily available image registration technique that does not require matching algorithms. The operator performs rigid-body transformations interactively. The precision of Manual fusion (as implemented on the Philips Pinnacle treatment planning system) was required for cranial CT-MR images used in radiotherapy planning for typical centrally located planning target volumes . Materials and Methods: A multi-stage Manual fusion procedure was developed which 11 observers followed to match the head contour, bones, soft tissues and contoured structures for 5 patient image-sets. Registration parameters were calculated by solving the transformation matrix following a consistent order of translations (T) and rotations (R). The mean position of centre of each planning target volumes averaged over all observers was used as the reference. The effect of mis registration on the planning target volumes co-ordinates and the volume increase resulting from application of a margin for registration uncertainty were calculated. Results: Mean intra- and inter-observer T/R SDs were 0.5 mm/ 0.4 d ig a nd 1.1 mm/ 1.0 d ig , respectively. Mean intra- and inter-observer registration error (3D distance of each planning target volumes centre from the mean position for all observers) was 0.7 ±0.3 mm (1 SD) and 1.6±0.7 mm respectively, the latter reducing to 1.4±0.6 mm excluding the 3 least experienced operators. A subsequent 2 mm margin for mis registration on average increased the planning target volume by 27%. Conclusion: Moderately trained operators produced clinically acceptable results while experienced operators improved the precision. Manual fusion still has an important role in the registration of cranial CT and MR images for radiotherapy planning especially for under-resourced centers

  20. Vector-model-supported optimization in volumetric-modulated arc stereotactic radiotherapy planning for brain metastasis

    International Nuclear Information System (INIS)

    Liu, Eva Sau Fan; Wu, Vincent Wing Cheung; Harris, Benjamin; Foote, Matthew; Lehman, Margot; Chan, Lawrence Wing Chi

    2017-01-01

    Long planning time in volumetric-modulated arc stereotactic radiotherapy (VMA-SRT) cases can limit its clinical efficiency and use. A vector model could retrieve previously successful radiotherapy cases that share various common anatomic features with the current case. The prsent study aimed to develop a vector model that could reduce planning time by applying the optimization parameters from those retrieved reference cases. Thirty-six VMA-SRT cases of brain metastasis (gender, male [n = 23], female [n = 13]; age range, 32 to 81 years old) were collected and used as a reference database. Another 10 VMA-SRT cases were planned with both conventional optimization and vector-model-supported optimization, following the oncologists' clinical dose prescriptions. Planning time and plan quality measures were compared using the 2-sided paired Wilcoxon signed rank test with a significance level of 0.05, with positive false discovery rate (pFDR) of less than 0.05. With vector-model-supported optimization, there was a significant reduction in the median planning time, a 40% reduction from 3.7 to 2.2 hours (p = 0.002, pFDR = 0.032), and for the number of iterations, a 30% reduction from 8.5 to 6.0 (p = 0.006, pFDR = 0.047). The quality of plans from both approaches was comparable. From these preliminary results, vector-model-supported optimization can expedite the optimization of VMA-SRT for brain metastasis while maintaining plan quality.

  1. Retrieval with Clustering in a Case-Based Reasoning System for Radiotherapy Treatment Planning

    International Nuclear Information System (INIS)

    Khussainova, Gulmira; Petrovic, Sanja; Jagannathan, Rupa

    2015-01-01

    Radiotherapy treatment planning aims to deliver a sufficient radiation dose to cancerous tumour cells while sparing healthy organs in the tumour surrounding area. This is a trial and error process highly dependent on the medical staff's experience and knowledge. Case-Based Reasoning (CBR) is an artificial intelligence tool that uses past experiences to solve new problems. A CBR system has been developed to facilitate radiotherapy treatment planning for brain cancer. Given a new patient case the existing CBR system retrieves a similar case from an archive of successfully treated patient cases with the suggested treatment plan. The next step requires adaptation of the retrieved treatment plan to meet the specific demands of the new case. The CBR system was tested by medical physicists for the new patient cases. It was discovered that some of the retrieved cases were not suitable and could not be adapted for the new cases. This motivated us to revise the retrieval mechanism of the existing CBR system by adding a clustering stage that clusters cases based on their tumour positions. A number of well-known clustering methods were investigated and employed in the retrieval mechanism. Results using real world brain cancer patient cases have shown that the success rate of the new CBR retrieval is higher than that of the original system. (paper)

  2. Retrieval with Clustering in a Case-Based Reasoning System for Radiotherapy Treatment Planning

    Science.gov (United States)

    Khussainova, Gulmira; Petrovic, Sanja; Jagannathan, Rupa

    2015-05-01

    Radiotherapy treatment planning aims to deliver a sufficient radiation dose to cancerous tumour cells while sparing healthy organs in the tumour surrounding area. This is a trial and error process highly dependent on the medical staff's experience and knowledge. Case-Based Reasoning (CBR) is an artificial intelligence tool that uses past experiences to solve new problems. A CBR system has been developed to facilitate radiotherapy treatment planning for brain cancer. Given a new patient case the existing CBR system retrieves a similar case from an archive of successfully treated patient cases with the suggested treatment plan. The next step requires adaptation of the retrieved treatment plan to meet the specific demands of the new case. The CBR system was tested by medical physicists for the new patient cases. It was discovered that some of the retrieved cases were not suitable and could not be adapted for the new cases. This motivated us to revise the retrieval mechanism of the existing CBR system by adding a clustering stage that clusters cases based on their tumour positions. A number of well-known clustering methods were investigated and employed in the retrieval mechanism. Results using real world brain cancer patient cases have shown that the success rate of the new CBR retrieval is higher than that of the original system.

  3. Plan of the day selection for online image-guided adaptive post-prostatectomy radiotherapy.

    Science.gov (United States)

    Gill, Suki; Pham, Daniel; Dang, Kim; Bressel, Mathias; Kron, Tomas; Siva, Shankar; Tran, Phillip K; Tai, Keen Hun; Foroudi, Farshad

    2013-05-01

    To compare the cone-beam CT (CBCT) soft tissue localization disparity between radiation oncologists (RO) and radiation therapy technologists (RTT) in a novel online protocol of image-guided adaptive radiotherapy to the postoperative prostate bed. Using the planning CT and pre-treatment CBCTs from the first week of radiotherapy, four adaptive plans of different sizes were derived for each of eight post-prostatectomy patients. Four ROs collectively defined the reference answer, i.e. the plan of the day and isocentre correction for 40 CBCTs taken in weeks 2-6 of treatment for each patient. RTTs were randomly assigned five of these CBCTs; and asked to record their plan of the day selection and isocentre correction. RTT selection and reference answers were compared. The distance between the RTT selection and the reference answer was calculated. A total of 33 RTTs took part in this study. The average difference in CTV volume (reference answer-RTT selection) was 1.32 cm(3) (SD 29 cm(3)) overall. The average difference between reference answer and RTT isocentre coordinates was SI 1mm (SD 4.8mm), LR 1.1mm (SD 4.0mm) and AP -0.2mm (SD 3.9 mm). Distance of superior 8mm, inferior 6mm, left 4mm, right 2mm, anterior 6mm and posterior 6mm covered 100% of the CTV in 90% of fractions. The difference between RTT and RO selection of adaptive volumes is small and can be accounted for in a clinically acceptable CTV to PTV margin. Adaptive post-prostatectomy radiotherapy is feasible, in the setting of an academic center although at the moment, we have insufficient evidence to suggest that margins can yet be reduced with IGART with the current protocol. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Audit of an automated checklist for quality control of radiotherapy treatment plans

    International Nuclear Information System (INIS)

    Breen, Stephen L.; Zhang Beibei

    2010-01-01

    Purpose: To assess the effect of adding an automated checklist to the treatment planning process for head and neck intensity-modulated radiotherapy. Methods: Plans produced within our treatment planning system were evaluated at the planners' discretion with an automated checklist of more than twenty planning parameters. Plans were rated as accepted or rejected for treatment, during regular review by radiation oncologists and physicists as part of our quality control program. The rates of errors and their types were characterised prior to the implementation of the checklist and with the checklist. Results: Without the checklist, 5.9% of plans were rejected; the use of the checklist reduced the rejection rate to 3.1%. The checklist was used for 64.7% of plans. Pareto analysis of the causes of rejection showed that the checklist reduced the number of causes of rejections from twelve to seven. Conclusions: The use of an automated checklist has reduced the need for reworking of treatment plans. With the use of the checklist, most rejections were due to errors in prescription or inadequate dose distributions. Use of the checklist by planners must be increased to maximise improvements in planning efficiency.

  5. Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongbao [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing (China); Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Hoisak, Jeremy D.P.; Li, Nan; Jiang, Carrie [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Tian, Zhen [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Gautier, Quentin; Zarepisheh, Masoud [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Wu, Zhaoxia; Liu, Yaqiang [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing (China); Jia, Xun [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); and others

    2015-01-01

    Stereotactic body radiotherapy (SBRT) shows promise in unresectable pancreatic cancer, though this treatment modality has high rates of normal tissue toxicity. This study explores the dosimetric utility of daily adaptive re-planning with pancreas SBRT. We used a previously developed supercomputing online re-planning environment (SCORE) to re-plan 10 patients with pancreas SBRT. Tumor and normal tissue contours were deformed from treatment planning computed tomographies (CTs) and transferred to daily cone-beam CT (CBCT) scans before re-optimizing each daily treatment plan. We compared the intended radiation dose, the actual radiation dose, and the optimized radiation dose for the pancreas tumor planning target volume (PTV) and the duodenum. Treatment re-optimization improved coverage of the PTV and reduced dose to the duodenum. Within the PTV, the actual hot spot (volume receiving 110% of the prescription dose) decreased from 4.5% to 0.5% after daily adaptive re-planning. Within the duodenum, the volume receiving the prescription dose decreased from 0.9% to 0.3% after re-planning. It is noteworthy that variation in the amount of air within a patient's stomach substantially changed dose to the PTV. Adaptive re-planning with pancreas SBRT has the ability to improve dose to the tumor and decrease dose to the nearby duodenum, thereby reducing the risk of toxicity.

  6. Evaluation of compensation in breast radiotherapy: a planning study using multiple static fields

    International Nuclear Information System (INIS)

    Donovan, Ellen M.; Johnson, Ursula; Shentall, Glyn; Evans, Philip M.; Neal, Anthony J.; Yarnold, John R.

    2000-01-01

    Purpose: A method that uses electronic portal imaging to design intensity-modulated beams for compensation in breast radiotherapy was implemented using multiple static fields in a planning study. We present the results of the study to verify the algorithm, and to assess improvements to the dosimetry. Methods and Materials: Fourteen patients were imaged with computed tomography (CT) and on a treatment unit using an electronic portal imager. The portal imaging data were used to design intensity-modulated beams to give an ideal dose distribution in the breast. These beams were implemented as multiple static fields added to standard wedged tangential fields. Planning of these treatments was performed on a commercial treatment planning system (Target 2, IGE Medical Systems, Slough, U.K.) using the CT data for each patient. Dose-volume histogram (DVH) analysis of the plans with and without multileaf collimator (MLC) compensation was carried out. This work has been used as the basis for a randomized clinical trial investigating whether improvements in dosimetry are correlated with the reduction of long-term side effects from breast radiotherapy. Results: The planning analysis showed a mean increase in target volume receiving 95-105% of prescribed dose of 7.5% (range -0.8% to 15.9%) when additional MLC compensation was applied. There was no change to the minimum dose for all 14 patient data sets. The change in the volume of breast tissue receiving over 105% of prescribed dose, when applying MLC compensation, was between -1.4% and 11.9%, with positive numbers indicating an improvement. These effects showed a correlation with breast size; the larger the breast the greater the amount of improvement. Conclusions: The method for designing compensation for breast treatments using an electronic portal imager has been verified using planning on CT data for 14 patients. An improvement was seen in planning when applying MLC compensation and this effect was greater the larger the

  7. Towards the development of an error checker for radiotherapy treatment plans: a preliminary study

    Science.gov (United States)

    Azmandian, Fatemeh; Kaeli, David; Dy, Jennifer G.; Hutchinson, Elizabeth; Ancukiewicz, Marek; Niemierko, Andrzej; Jiang, Steve B.

    2007-11-01

    Major accidents can happen during radiotherapy, with an extremely severe consequence to both patients and clinical professionals. We propose to use machine learning and data mining techniques to help detect large human errors in a radiotherapy treatment plan, as a complement to human inspection. One such technique is computer clustering. The basic idea of using clustering algorithms for outlier detection is to first cluster (based on the treatment parameters) a large number of patient treatment plans. Then, when checking a new treatment plan, the parameters of the plan will be tested to see whether or not they belong to the established clusters. If not, they will be considered as 'outliers' and therefore highlighted to catch the attention of the human chart checkers. As a preliminary study, we applied the K-means clustering algorithm to a simple patient model, i.e., 'four-field' box prostate treatment. One thousand plans were used to build the clusters while another 650 plans were used to test the proposed method. It was found that there are eight distinct clusters. At the error levels of ±100% of the original values of the monitor unit, the detection rate is about 100%. At ±50% error level, the detection rate is about 80%. The false positive rate is about 10%. When purposely changing the beam energy to a value different from that in the treatment plan, the detection rate is 100% for posterior, right-lateral and left-lateral fields, and about 77% for the anterior field. This preliminary work has shown promise for developing the proposed automatic outlier detection software, although more efforts will still be required.

  8. A multicriteria framework with voxel-dependent parameters for radiotherapy treatment plan optimization

    International Nuclear Information System (INIS)

    Zarepisheh, Masoud; Uribe-Sanchez, Andres F.; Li, Nan; Jia, Xun; Jiang, Steve B.

    2014-01-01

    Purpose: To establish a new mathematical framework for radiotherapy treatment optimization with voxel-dependent optimization parameters. Methods: In the treatment plan optimization problem for radiotherapy, a clinically acceptable plan is usually generated by an optimization process with weighting factors or reference doses adjusted for a set of the objective functions associated to the organs. Recent discoveries indicate that adjusting parameters associated with each voxel may lead to better plan quality. However, it is still unclear regarding the mathematical reasons behind it. Furthermore, questions about the objective function selection and parameter adjustment to assure Pareto optimality as well as the relationship between the optimal solutions obtained from the organ-based and voxel-based models remain unanswered. To answer these questions, the authors establish in this work a new mathematical framework equipped with two theorems. Results: The new framework clarifies the different consequences of adjusting organ-dependent and voxel-dependent parameters for the treatment plan optimization of radiation therapy, as well as the impact of using different objective functions on plan qualities and Pareto surfaces. The main discoveries are threefold: (1) While in the organ-based model the selection of the objective function has an impact on the quality of the optimized plans, this is no longer an issue for the voxel-based model since the Pareto surface is independent of the objective function selection and the entire Pareto surface could be generated as long as the objective function satisfies certain mathematical conditions; (2) All Pareto solutions generated by the organ-based model with different objective functions are parts of a unique Pareto surface generated by the voxel-based model with any appropriate objective function; (3) A much larger Pareto surface is explored by adjusting voxel-dependent parameters than by adjusting organ-dependent parameters, possibly

  9. A multicriteria framework with voxel-dependent parameters for radiotherapy treatment plan optimization.

    Science.gov (United States)

    Zarepisheh, Masoud; Uribe-Sanchez, Andres F; Li, Nan; Jia, Xun; Jiang, Steve B

    2014-04-01

    To establish a new mathematical framework for radiotherapy treatment optimization with voxel-dependent optimization parameters. In the treatment plan optimization problem for radiotherapy, a clinically acceptable plan is usually generated by an optimization process with weighting factors or reference doses adjusted for a set of the objective functions associated to the organs. Recent discoveries indicate that adjusting parameters associated with each voxel may lead to better plan quality. However, it is still unclear regarding the mathematical reasons behind it. Furthermore, questions about the objective function selection and parameter adjustment to assure Pareto optimality as well as the relationship between the optimal solutions obtained from the organ-based and voxel-based models remain unanswered. To answer these questions, the authors establish in this work a new mathematical framework equipped with two theorems. The new framework clarifies the different consequences of adjusting organ-dependent and voxel-dependent parameters for the treatment plan optimization of radiation therapy, as well as the impact of using different objective functions on plan qualities and Pareto surfaces. The main discoveries are threefold: (1) While in the organ-based model the selection of the objective function has an impact on the quality of the optimized plans, this is no longer an issue for the voxel-based model since the Pareto surface is independent of the objective function selection and the entire Pareto surface could be generated as long as the objective function satisfies certain mathematical conditions; (2) All Pareto solutions generated by the organ-based model with different objective functions are parts of a unique Pareto surface generated by the voxel-based model with any appropriate objective function; (3) A much larger Pareto surface is explored by adjusting voxel-dependent parameters than by adjusting organ-dependent parameters, possibly allowing for the

  10. Dosimetric inter-institutional comparison in European radiotherapy centres: Results of IAEA supported treatment planning system audit.

    Science.gov (United States)

    Gershkevitsh, Eduard; Pesznyak, Csilla; Petrovic, Borislava; Grezdo, Joseph; Chelminski, Krzysztof; do Carmo Lopes, Maria; Izewska, Joanna; Van Dyk, Jacob

    2014-05-01

    One of the newer audit modalities operated by the International Atomic Energy Agency (IAEA) involves audits of treatment planning systems (TPS) in radiotherapy. The main focus of the audit is the dosimetry verification of the delivery of a radiation treatment plan for three-dimensional (3D) conformal radiotherapy using high energy photon beams. The audit has been carried out in eight European countries - Estonia, Hungary, Latvia, Lithuania, Serbia, Slovakia, Poland and Portugal. The corresponding results are presented. The TPS audit reviews the dosimetry, treatment planning and radiotherapy delivery processes using the 'end-to-end' approach, i.e. following the pathway similar to that of the patient, through imaging, treatment planning and dose delivery. The audit is implemented at the national level with IAEA assistance. The national counterparts conduct the TPS audit at local radiotherapy centres through on-site visits. TPS calculated doses are compared with ion chamber measurements performed in an anthropomorphic phantom for eight test cases per algorithm/beam. A set of pre-defined agreement criteria is used to analyse the performance of TPSs. TPS audit was carried out in 60 radiotherapy centres. In total, 190 data sets (combination of algorithm and beam quality) have been collected and reviewed. Dosimetry problems requiring interventions were discovered in about 10% of datasets. In addition, suboptimal beam modelling in TPSs was discovered in a number of cases. The TPS audit project using the IAEA methodology has verified the treatment planning system calculations for 3D conformal radiotherapy in a group of radiotherapy centres in Europe. It contributed to achieving better understanding of the performance of TPSs and helped to resolve issues related to imaging, dosimetry and treatment planning.

  11. Multi-institutional comparison of simulated treatment delivery errors in ssIMRT, manually planned VMAT and autoplan-VMAT plans for nasopharyngeal radiotherapy

    DEFF Research Database (Denmark)

    Pogson, Elise M; Aruguman, Sankar; Hansen, Christian R

    2017-01-01

    PURPOSE: To quantify the impact of simulated errors for nasopharynx radiotherapy across multiple institutions and planning techniques (auto-plan generated Volumetric Modulated Arc Therapy (ap-VMAT), manually planned VMAT (mp-VMAT) and manually planned step and shoot Intensity Modulated Radiation...... Therapy (mp-ssIMRT)). METHODS: Ten patients were retrospectively planned with VMAT according to three institution's protocols. Within one institution two further treatment plans were generated using differing treatment planning techniques. This resulted in mp-ssIMRT, mp-VMAT, and ap-VMAT plans. Introduced...

  12. CT and MRI matching for radiotherapy planning in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, C.; Keus, R.; Touw, A.; Lebesque, J.; Van Herk, M. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    The objective of this study was to evaluate the impact of matched CT and MRI information on target delineation in radiotherapy planning for head and neck tumors. MRI images of eight patients with head and neck cancer in supine position, not necessarily obtained in radiotherapy treatment position were matched to the CT scans made in radiotherapy position using automatic three-dimensional chamfer-matching of bony structures. Four independent observers delineated the Gross Tumor Volume (GTV) in CT scans and axial and sagittal MR scans. The GTV`s were compared, overlapping volumes and non-overlapping volumes between the different datasets and observers were determined. In all patients a good match of CT and MRI information was accomplished in the head region. The combined information provided a better visualisation of the GTV, oedema and normal tissues compared with CT or MRI alone. Determination of overlapping and non-overlapping volumes proved to be a valuable tool to measure uncertainties in the determination of the GTV. CT-MRI matching in patients with head and neck tumors is feasible and makes a more accurate irradiation with higher tumor doses and less normal tissue complications possible. Remaining uncertainties in the determination of the GTV can be quantified using the combined information of MRI and CT.

  13. Geometric moments and artificial neural network in per optimization of radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Yahaqi, E.; Movafeghi, A.; Hosseini- Ashrafi, M.E.

    2004-01-01

    Given the number of possible combinations of different setting in radiotherapy such as the number of fields etc., arriving at an optimum treatment plan with a completely conventional solution would require an unacceptable number of interaction. Using a priori information whether of a qualitative or quantitative nature has the potential of greatly reducing amount of calculation required in any optimization procedure. Having extracted the outline of the body counter line the treatment area, the sensitive organ and any in- homogeneity present in the given cross section quantitative information in the form of moments is calculated for each treatment case. An artificial neural network classifier is then developed using group of sample treatment case and applied to arrive at initial treatment plan for any new case. The approach has been shown to have strong potential for greatly reducing the number of choices in selecting the optimum answer in treatment planning

  14. CT images and radiotherapy treatment planning of patients with breast cancer: A dataset

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaei

    2017-08-01

    Full Text Available The data presented here were originally collected for the research project “CT-Scan processing and analysis in patient with breast cancer after radiotherapy”. Also, it reported in our study “Prediction of Lung Tissue Damage by Evaluating Clinical and Dosimetric Parameters in Breast Cancer Patients” (Hasanabdali et al., 2016 [1]. This article describes and directly links to 52 subjects referred to Mahdieh Oncology and Radiotherapy Center from February to August 2015. Treatment planning was done for delivering 50 Gy dose to PTV in 25 fractions. the lungs and heart objects were extracted from CT images along with compliance Dose plan. Dose-volume histogram (DVH and Dose-mass histogram (DMH extracted using CT images and dose plan matrix. Moreover, the complete clinical and dosimetric specifications of subjects is attached.

  15. PET/CT fusion in radiotherapy planning for lung cancer - case reports

    Directory of Open Access Journals (Sweden)

    Erak Marko Đ.

    2016-01-01

    Full Text Available Introduction. Application of imaging methods, namely computed tomography (CT, magnetic resonance imaging (MRI and in recent years positron emission tomography-computed tomography (PET/CT, and the progress of computer technology have allowed the construction of effective computerized systems for treatment planning (TPS and introducing the concept of virtual simulation in 3D conformal radiotherapy planning. Case report. We hereby presented two patients with the diagnosis of non-small cell lung cancer who did PET/CT examination. Both patients had surgery earlier and local recidives are diagnosed with PET/CT. PET/CT of the first patient described the focus of intense fluorodeoxyglucose (FDG accumulation 2.99 × 2.9 × 2.1cm in diameter in the projection of soft-tissue volume in the left corner, at operating clips height, corresponding to metabolically active recurrence of the tumor. Mediastinum and right lung parenchyma were without focal accumulation of FDG. Control PET/CT after 3 months was without detectable focus of intense pathological FDG accumulation - good therapeutic response, (metabolic disease remission. On the other hand, in the second case PET/CT showed a focus of intense FDG accumulation screening in the scar tissue of the apical part of the right lung, 20 × 16 mm, corresponding to metabolically active tumor recurrence. In the lung parenchyma on the left and in the mediastinum no visible focus of intense FDG accumulation was descrbed. Radiography included using 3D conformal radiotherapy with fusion PET/CT scan and CT simulations. Conclusion. PET/CT provides important information for planning conformal radiotherapy, especially in dose escalation, sparing of organ at risk and better locoregional control of the disease.

  16. The need for radiotherapy in Europe in 2020: Not only data but also a cancer plan.

    Science.gov (United States)

    Borras, Josep M; Lievens, Yolande; Grau, Cai

    2015-01-01

    Planning radiation oncology equipment and staffing is necessary in public healthcare systems in Europe. Three different data inputs were considered: evidence-based indications for radiotherapy, the incidence of cancer, and the stage at diagnosis of each cancer type, both the latter using population-based data from cancer registries. The availability of these data and the implications for the estimation of the proportion of new cancer patients who would need radiotherapy treatment at least once during the course of the disease is reviewed. Depending on the frequency of cancers and the stage at diagnosis, it has been estimated that between 47% and 53% of incident cases among European countries would require external beam radiotherapy. When the actual data of utilization is compared with the evidence-based target, only one country in Europe has achieved full coverage. It is argued that these should be considered the optimal proportions of cancer patients, but a more realistic policy target could be set at 80% or higher of the optimal proportion. This realistic target also takes into account the inherent uncertainties in the assessment of evidence, and other factors that influence clinical decision-making in cases of multi-morbidity or patient preferences. Other factors are associated with problems that should be dealt with in the framework of a cancer plan, such as accessibility, preference bias in physician evaluation of the indication or shortage of resources, and the impact of the reimbursement system. Finally, it is argued that a cancer plan is the framework for achieving policy targets in the appropriate coverage of the evidence-based indications for radiation oncology forecasts.

  17. SU-F-T-208: An Efficient Planning Approach to Posterior Fossa Tumor Bed Boosts Using Proton Pencil Beam Scanning in Fixed-Beam Room

    Energy Technology Data Exchange (ETDEWEB)

    Ju, N; Chen, C; Gans, S; Hug, E; Cahlon, O; Chon, B; Tsai, H; Sine, K; Mah, D [Procure Treatment Center, Somerset, New Jersey (United States); Wolden, S [Memorial Sloan Kettering Cancer Center, New York, NY (United States); Yeh, B [Mount Sinai Hospital, New York, NY (United States)

    2016-06-15

    Purpose: A fixed-beam room could be underutilized in a multi-room proton center. We investigated the use of proton pencil beam scanning (PBS) on a fixed-beam as an alternative for posterior fossa tumor bed (PF-TB) boost treatments which were usually treating on a gantry with uniform scanning. Methods: Five patients were treated with craniospinal irradiation (CSI, 23.4 or 36.0 Gy(RBE)) followed by a PF-TB boost to 54 Gy(RBE) with proton beams. Three PF-TB boost plans were generated for each patient: (1) a uniform scanning (US) gantry plan with 4–7 posterior fields shaped with apertures and compensators (2) a PBS plan using bi-lateral and vertex fields with a 3-mm planning organ-at-risk volume (PRV) expansion around the brainstem and (3) PBS fields using same beam arrangement but replacing the PRV with robust optimization considering a 3-mm setup uncertainty. Results: A concave 54-Gy(RBE) isodose line surrounding the brainstem could be achieved using all three techniques. The mean V95% of the PTV was 99.7% (range: 97.6% to 100%) while the V100% of the PTV ranged from 56.3% to 93.1% depending on the involvement of the brainstem with the PTV. The mean doses received by 0.05 cm{sup 3} of the brainstem were effectively identical: 54.0 Gy(RBE), 53.4 Gy(RBE) and 53.3 Gy(RBE) for US, PBS optimized with PRV, and PBS optimized with robustness plans respectively. The cochlea mean dose increased by 23% of the prescribed boost dose in average from the bi-lateral fields used in the PBS plan. Planning time for the PBS plan with PRV was 5–10 times less than the US plan and the robustly optimized PBS plan. Conclusion: We have demonstrated that a fixed-beam with PBS can deliver a dose distribution comparable to a gantry plan using uniform scanning. Planning time can be reduced substantially using a PRV around the brainstem instead of robust optimization.

  18. Optimization of stereotactic body radiotherapy treatment planning using a multicriteria optimization algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Ghandour, Sarah; Cosinschi, Adrien; Mazouni, Zohra; Pachoud, Marc; Matzinger, Oscar [Riviera-Chablais Hospital, Vevey (Switzerland). Cancer Center, Radiotherapy Dept.

    2016-07-01

    To provide high-quality and efficient dosimetric planning for various types of stereotactic body radiotherapy (SBRT) for tumor treatment using a multicriteria optimization (MCO) technique fine-tuned with direct machine parameter optimization (DMPO). Eighteen patients with lung (n = 11), liver (n = 5) or adrenal cell cancer (n = 2) were treated using SBRT in our clinic between December 2014 and June 2015. Plans were generated using the RayStation trademark Treatment Planning System (TPS) with the VMAT technique. Optimal deliverable SBRT plans were first generated using an MCO algorithm to find a well-balanced tradeoff between tumor control and normal tissue sparing in an efficient treatment planning time. Then, the deliverable plan was post-processed using the MCO solution as the starting point for the DMPO algorithm to improve the dose gradient around the planning target volume (PTV) while maintaining the clinician's priorities. The dosimetric quality of the plans was evaluated using dose-volume histogram (DVH) parameters, which account for target coverage and the sparing of healthy tissue, as well as the CI100 and CI50 conformity indexes. Using a combination of the MCO and DMPO algorithms showed that the treatment plans were clinically optimal and conformed to all organ risk dose volume constraints reported in the literature, with a computation time of approximately one hour. The coverage of the PTV (D99% and D95%) and sparing of organs at risk (OAR) were similar between the MCO and MCO + DMPO plans, with no significant differences (p > 0.05) for all the SBRT plans. The average CI100 and CI50 values using MCO + DMPO were significantly better than those with MCO alone (p < 0.05). The MCO technique allows for convergence on an optimal solution for SBRT within an efficient planning time. The combination of the MCO and DMPO techniques yields a better dose gradient, especially for lung tumors.

  19. Design of security scheme of the radiotherapy planning administration system based on the hospital information system

    International Nuclear Information System (INIS)

    Zhuang Yongzhi; Zhao Jinzao

    2010-01-01

    Objective: To design a security scheme of radiotherapy planning administration system. Methods: Power Builder 9i language was used to program the system through the model of client-server machine. Oracle 9i was used as the database server. Results In this system, user registration management, user login management, application-level functions of control, database access control, and audit trail were designed to provide system security. Conclusions: As a prototype for the security analysis and protection of this scheme provides security of the system, application system, important data and message, which ensures the system work normally. (authors)

  20. Physical-dosimetric enabling a dual linear accelerator 3D planning systems for radiotherapy

    International Nuclear Information System (INIS)

    Alfonso, Rodolfo; Martinez, William; Arelis, Lores; Morales, Jorge

    2009-01-01

    The process of commissioning clinical linear accelerator requires a dual comprehensive study of the therapeutic beam parameters, both photons Electron. All information gained by measuring physical and dosimetric these beams must be analyzed, processed and refined for further modeling in computer-based treatment planning (RTPS). Of professionalism of this process will depend on the accuracy and precision of the calculations the prescribed doses. This paper aims to demonstrate availability clinical linear accelerator system-RTPS with late radiotherapy treatments shaped beam of photons and electrons. (author)

  1. Radiation dose differences between thoracic radiotherapy planning CT and thoracic diagnostic CT scans

    International Nuclear Information System (INIS)

    Sanderud, A.; England, A.; Hogg, P.; Fosså, K.; Svensson, S.F.; Johansen, S.

    2016-01-01

    Purpose: To compare the absorbed dose from computed tomography (CT) in radiotherapy planning (RP-CT) against those from diagnostic CT (DG-CT) examinations and to explore the possible reasons for any dose differences. Method: Two groups of patients underwent CT-scans of the thorax with either DG-CT (n = 55) or RP-CT (n = 55). Patients from each group had similar weight and body mass index (BMI) and were divided into low (<25) and high BMI (>25). Parameters including CTDIvol, DLP and scan-length were compared. Results: The mean CTDIvol and DLP values from RP-CT (38.1 mGy, 1472 mGy cm) are approximately four times higher than for DG-CT (9.63 mGy, 376.5 mGy cm). For low BMI group, the CTDIvol in the RP-CT scans (36.4 mGy) is 6.3 times higher than the one in the DG-CT scans (5.8 mGy). For the high BMI group, the CTDIvol in the RP-CT (39.6 mGy) is 2.5 times higher than the one in the DG-CT scans (15.8 mGy). In the DG-CT scans a strong negative linear correlation between noise index (NI) and mean CTDIvol was observed (r = −0.954, p = 0.004); the higher NI, the lower CTDIvol. This was not the case in the RP-CT scans. Conclusion: The absorbed radiation dose is significantly higher and less BMI dependent for RP-CT scans compared to DG-CT. Image quality requirements of the examinations should be researched to ensure that radiation doses are not unnecessarily high. - Highlights: • The radiation dose differences in diagnostic vs. radiotherapy planning thorax CT. • The average effective dose given to radiotherapy planning patients are 30.0 mSv. • The average effective dose given to diagnostic patients are 7.7 mSv. • The CTDIvol is less BMI dependent for radiotherapy planning thorax CT scans compared to diagnostic scans.

  2. Potential impact of 68Ga-DOTATOC PET/CT on stereotactic radiotherapy planning of meningiomas

    International Nuclear Information System (INIS)

    Nyuyki, Fonyuy; Plotkin, Michail; Michel, Roger; Steffen, Ingo; Fahdt, Daniel; Brenner, Winfried; Graf, Reinhold; Denecke, Timm; Geworski, Lilli; Wurm, Reinhard

    2010-01-01

    Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with 68 Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planning radiotherapy. We investigated the input of 68 Ga-DOTATOC-PET/CT on the definition of the ''gross tumour volume'' (GTV) in meningiomas, in order to assess the potential value of this method. Prior to radiotherapy, 42 patients with meningiomas (26 f, 16 m, mean age 55) underwent MRI and 68 Ga-DOTATOC-PET/CT examinations. History: operated n = 24, radiotherapy n = 1, operation and radiotherapy n = 8, no treatment n = 9. PET/CT and MRI data were co-registered using a BrainLAB workstation. For comparison, the GTV was defined first under consideration of CT and MRI data, then using PET data. 3/42 patients were excluded from the analysis (two with negative PET results, one with an extensive tumour, not precisely delineable by MRI or PET/CT). The average GTV CT/MRI was 22(±19)cm 3 ; GTV PET was 23(±20)cm 3 . Additional GTV, obtained as a result of PET was 9(±10)cm 3 and was observed in patients with osseous infiltration. In some pre-treated patients there were intratumoural areas (as identified in CT/MRI) without SR-expression (7(±11)cm 3 ). Common GTV as obtained by both CT/MRI and PET was 15(±14)cm 3 . The mean bi-directional difference between the GTV CT/MRI and GTV PET accounted to 16(±15)cm 3 (93%, p 68 Ga-DOTATOC-PET enables delineation of SR-positive meningiomas and delivers additional information to both CT and MRI regarding the planning of stereotactic radiotherapy. The acquisition on a PET/CT scanner helps to estimate the relation of PET findings to anatomical structures and is especially useful for detection of osseous infiltration. 68 Ga-DOTATOC-PET also allows detection of additional lesions in patients with multiple meningiomas. (orig.)

  3. 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

  4. Dosimetric verification of radiotherapy treatment planning systems in Serbia: national audit.

    Science.gov (United States)

    Rutonjski, Laza; Petrović, Borislava; Baucal, Milutin; Teodorović, Milan; Cudić, Ozren; Gershkevitsh, Eduard; Izewska, Joanna

    2012-09-12

    Independent external audits play an important role in quality assurance programme in radiation oncology. The audit supported by the IAEA in Serbia was designed to review the whole chain of activities in 3D conformal radiotherapy (3D-CRT) workflow, from patient data acquisition to treatment planning and dose delivery. The audit was based on the IAEA recommendations and focused on dosimetry part of the treatment planning and delivery processes. The audit was conducted in three radiotherapy departments of Serbia. An anthropomorphic phantom was scanned with a computed tomography unit (CT) and treatment plans for eight different test cases involving various beam configurations suggested by the IAEA were prepared on local treatment planning systems (TPSs). The phantom was irradiated following the treatment plans for these test cases and doses in specific points were measured with an ionization chamber. The differences between the measured and calculated doses were reported. The measurements were conducted for different photon beam energies and TPS calculation algorithms. The deviation between the measured and calculated values for all test cases made with advanced algorithms were within the agreement criteria, while the larger deviations were observed for simpler algorithms. The number of measurements with results outside the agreement criteria increased with the increase of the beam energy and decreased with TPS calculation algorithm sophistication. Also, a few errors in the basic dosimetry data in TPS were detected and corrected. The audit helped the users to better understand the operational features and limitations of their TPSs and resulted in increased confidence in dose calculation accuracy using TPSs. The audit results indicated the shortcomings of simpler algorithms for the test cases performed and, therefore the transition to more advanced algorithms is highly desirable.

  5. Dosimetric verification of radiotherapy treatment planning systems in Serbia: national audit

    Directory of Open Access Journals (Sweden)

    Rutonjski Laza

    2012-09-01

    Full Text Available Abstract Background Independent external audits play an important role in quality assurance programme in radiation oncology. The audit supported by the IAEA in Serbia was designed to review the whole chain of activities in 3D conformal radiotherapy (3D-CRT workflow, from patient data acquisition to treatment planning and dose delivery. The audit was based on the IAEA recommendations and focused on dosimetry part of the treatment planning and delivery processes. Methods The audit was conducted in three radiotherapy departments of Serbia. An anthropomorphic phantom was scanned with a computed tomography unit (CT and treatment plans for eight different test cases involving various beam configurations suggested by the IAEA were prepared on local treatment planning systems (TPSs. The phantom was irradiated following the treatment plans for these test cases and doses in specific points were measured with an ionization chamber. The differences between the measured and calculated doses were reported. Results The measurements were conducted for different photon beam energies and TPS calculation algorithms. The deviation between the measured and calculated values for all test cases made with advanced algorithms were within the agreement criteria, while the larger deviations were observed for simpler algorithms. The number of measurements with results outside the agreement criteria increased with the increase of the beam energy and decreased with TPS calculation algorithm sophistication. Also, a few errors in the basic dosimetry data in TPS were detected and corrected. Conclusions The audit helped the users to better understand the operational features and limitations of their TPSs and resulted in increased confidence in dose calculation accuracy using TPSs. The audit results indicated the shortcomings of simpler algorithms for the test cases performed and, therefore the transition to more advanced algorithms is highly desirable.

  6. Planned neck dissection after weekly docetaxel and concurrent radiotherapy for advanced oropharyngeal cancer

    International Nuclear Information System (INIS)

    Tomita, Toshiki; Ozawa, Hiroyuki; Sakamoto, Koji; Fujii, Ryoichi; Ogawa, Kaoru; Fujii, Masato; Yamashita, Taku; Shinden, Seiichi

    2007-01-01

    Small oropharyngeal carcinomas with advanced neck metastases (stage N2 or greater) are common. Patients with small T with large N oropharyngeal carcinoma have high rates of local control but lower rates of regional control when treated with chemoradiotherapy. Clinical assessment after chemoradiotherapy cannot ensure the absence of neck disease. In the last 5 years, we have treated patients with T1-2 with N2-3 oropharyngeal carcinoma with weekly docetaxel radiotherapy followed by planned neck dissection (PND). Our objectives were to clarify the pathologically complete response (CR) rate of neck metastasis after weekly docetaxel radiotherapy, to identify the clinical predictor of residual neck disease, and to determine the mobidity of planned neck dissection. After chemoradiotherapy, all 12 patients had a complete response at the primary site. We conducted 15 neck dissections. Of these, 6 (40%) had positive nodes. The pathological CR rate of neck metastasis was 58.3%, whereas overall 2-year neck control rate was 91.7%. These findings lend support to the role of PND after chemoradiotherapy in N2-3 neck disease. After chemoradiotherapy, clinical parameters including TN status, feasibility of chemoradiotherapy, largest lymph node size or size reduction in MRI, did not identify patients with residual neck disease. We conducted selective neck dissection (SND) in 80% of patients. SND as PND appears to be appropriate in this group of patients because of the low incidence of complications. A further cohort study including the comparison of PND nonenforcement group is necessary to clarify the validity of the addition of PND in weekly docetaxel radiotherapy. (author)

  7. Segmentation of IMRT plans for radical lung radiotherapy delivery with the step-and-shoot technique

    International Nuclear Information System (INIS)

    Nioutsikou, Elena; Bedford, James L.; Christian, Judith A.; Brada, Michael; Webb, Steve

    2004-01-01

    The purpose of this work was to determine a segmentation protocol for the treatment of localized non-small-cell lung cancer (NSCLC) with intensity-modulated radiotherapy (IMRT) that is as effective as possible while practically simple and hence robust to known practical inaccuracies. This study focused on the stratification of continuous profiles into a discrete number of intensity levels. The selection of the segmentation parameters for the delivery of the fluence profiles using multiple static fields has been considered. Five-field equispaced IMRT treatment plans of five patients with NSCLC were selected. The study comprised nine treatment plans for each patient, starting from a conformal plan, optimizing it for IMRT and then segmenting it utilizing different numbers of segments in each case and optimizing for segment weights separately. A conformal plan, optimized for beam directions, collimator and wedge angles, was also used for comparison with the IMRT plans, so as to consider the best coplanar conformal case. A dose objective for the PTV and the organs-at-risk plus a constraint for the spinal cord were set for all inverse plans. All stages were compared with the aid of dose-volume histograms, dose distributions at the plane of the isocenter, intensity maps for key beams and plots of PTV homogeneity and overall conformality versus complexity. The unsegmented IMRT plans gave the best results but cannot be realized in practice with an MLC. They were best approximated by plans that needed 106-167 segments to deliver, but did not deteriorate significantly when approximated by plans which required 26-40 segments in total. All segmented IMRT plans gave a better lung sparing than the conformal plans, indicating that the deterioration of IMRT plans following segmentation is not equivalent to that of unmodulated, conformal plans. However, optimized conformal plans have the potential to approach the lung sparing achieved by segmented IMRT plans. Among the IMRT

  8. Breast conserving treatment of breast carcinoma T2 (≤ 4 cm) and T3 by neoadjuvant chemotherapy, quadrantectomy, high dose rate brachytherapy as a boost, external beam radiotherapy and adjuvant chemotherapy: local control and overall survival analysis

    International Nuclear Information System (INIS)

    Soares, Celia Regina; Miziara Filho, Miguel Abrao; Fogaroli, Ricardo Cesar; Baraldi, Helena Espindola; Pellizzon, Antonio Cassio Assis; Pelosi, Edilson Lopes

    2008-01-01

    Objective: to assess the treatment of breast cancer T2 (≤ 4 cm) and T3 through neoadjuvant chemotherapy, quadrantectomy and high dose rate brachytherapy as a boost, complementary radiotherapy and adjuvant chemotherapy, considering local control and overall survival. Material and method: this clinical prospective descriptive study was based on the evaluation of 88 patients ranging from 30 to 70 years old, with infiltrating ductal carcinoma, clinical stage IIb and IIIa, responsive to the neoadjuvant chemotherapy, treated from June/1995 to December/2006. Median follow-up was 58 months. Using clinical methods the tumor was evaluated before and after three or four cycles of chemotherapy based on anthracyclines. Overall survival and local control were assessed according to Kaplan-Meier methodology. Results: Local control and overall survival in five years were 90% and 73.5%, respectively. Conclusion: local control and overall survival were comparable to other forms of treatment. (author)

  9. Effect of contrast agent administration on consequences of dosimetry and biology in radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Ching-Jung [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Yang, Pei-Ying [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Chao, Tsi-Chian, E-mail: chaot@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Tu, Shu-Ju, E-mail: sjtu@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China)

    2015-06-01

    In the treatment planning of radiation therapy, patients may be administrated with contrast media in CT scanning to assist physicians for accurate delineation of the target or organs. However, contrast media are not used in patients during the treatment delivery. In particular, contrast media contain materials with high atomic numbers and dosimetric variations may occur between scenarios where contrast media are present in treatment planning and absent in treatment delivery. In this study we evaluate the effect of contrast media on the dosimetry and biological consequence. An analytical phantom based on AAPM TG 119 and five sets of CT images from clinical patients are included. Different techniques of treatment planning are considered, including 1-field AP, 2-field AP+PA, 4-field box, 7-field IMRT, and RapidArc. RapidArc is a recent technique of volumetric modulated arc therapy and is used in our study of contrast media in clinical scenarios. The effect of RapidArc on dosimetry and biological consequence for administration of contrast media in radiotherapy is not discussed previously in literature. It is shown that dose difference is reduced as the number of external beams is increased, suggesting RapidArc may be favored to be used in the treatment planning enhanced by contrast media. Linear trend lines are fitted for assessment of percent dose differences in the planning target volume versus concentrations of contrast media between plans where contrast media are present and absent, respectively.

  10. MRI-based treatment plan simulation and adaptation for ion radiotherapy using a classification-based approach

    International Nuclear Information System (INIS)

    Rank, Christopher M; Tremmel, Christoph; Hünemohr, Nora; Nagel, Armin M; Jäkel, Oliver; Greilich, Steffen

    2013-01-01

    In order to benefit from the highly conformal irradiation of tumors in ion radiotherapy, sophisticated treatment planning and simulation are required. The purpose of this study was to investigate the potential of MRI for ion radiotherapy treatment plan simulation and adaptation using a classification-based approach. Firstly, a voxelwise tissue classification was applied to derive pseudo CT numbers from MR images using up to 8 contrasts. Appropriate MR sequences and parameters were evaluated in cross-validation studies of three phantoms. Secondly, ion radiotherapy treatment plans were optimized using both MRI-based pseudo CT and reference CT and recalculated on reference CT. Finally, a target shift was simulated and a treatment plan adapted to the shift was optimized on a pseudo CT and compared to reference CT optimizations without plan adaptation. The derivation of pseudo CT values led to mean absolute errors in the range of 81 - 95 HU. Most significant deviations appeared at borders between air and different tissue classes and originated from partial volume effects. Simulations of ion radiotherapy treatment plans using pseudo CT for optimization revealed only small underdosages in distal regions of a target volume with deviations of the mean dose of PTV between 1.4 - 3.1% compared to reference CT optimizations. A plan adapted to the target volume shift and optimized on the pseudo CT exhibited a comparable target dose coverage as a non-adapted plan optimized on a reference CT. We were able to show that a MRI-based derivation of pseudo CT values using a purely statistical classification approach is feasible although no physical relationship exists. Large errors appeared at compact bone classes and came from an imperfect distinction of bones and other tissue types in MRI. In simulations of treatment plans, it was demonstrated that these deviations are comparable to uncertainties of a target volume shift of 2 mm in two directions indicating that especially

  11. The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery

    DEFF Research Database (Denmark)

    Falk, Marianne; Larsson, Tobias; Keall, P.

    2012-01-01

    of MLC tracking delivery of an inversely optimized arc radiotherapy plan can be improved by incorporating leaf position constraints in the objective function without otherwise affecting the plan quality. The dosimetric robustness may be estimated prior to delivery by evaluating the ALDw of the plan.......Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced...... by using a leaf position constraint (LPC) that reduces the difference in the position of adjacent MLC leaves in the plan. The purpose of this study was to investigate the impact of the LPC on the quality of inversely optimized arc radiotherapy plans and the effect of the MLC motion pattern...

  12. Navigator channel adaptation to reconstruct three dimensional heart volumes from two dimensional radiotherapy planning data

    International Nuclear Information System (INIS)

    Ng, Angela; Nguyen, Thao-Nguyen; Moseley, Joanne L; Hodgson, David C; Sharpe, Michael B; Brock, Kristy K

    2012-01-01

    Biologically-based models that utilize 3D radiation dosimetry data to estimate the risk of late cardiac effects could have significant utility for planning radiotherapy in young patients. A major challenge arises from having only 2D treatment planning data for patients with long-term follow-up. In this study, we evaluate the accuracy of an advanced deformable image registration (DIR) and navigator channels (NC) adaptation technique to reconstruct 3D heart volumes from 2D radiotherapy planning images for Hodgkin's Lymphoma (HL) patients. Planning CT images were obtained for 50 HL patients who underwent mediastinal radiotherapy. Twelve image sets (6 male, 6 female) were used to construct a male and a female population heart model, which was registered to 23 HL 'Reference' patients' CT images using a DIR algorithm, MORFEUS. This generated a series of population-to-Reference patient specific 3D deformation maps. The technique was independently tested on 15 additional 'Test' patients by reconstructing their 3D heart volumes using 2D digitally reconstructed radiographs (DRR). The technique involved: 1) identifying a matching Reference patient for each Test patient using thorax measurements, 2) placement of six NCs on matching Reference and Test patients' DRRs to capture differences in significant heart curvatures, 3) adapting the population-to-Reference patient-specific deformation maps to generate population-to-Test patient-specific deformation maps using linear and bilinear interpolation methods, 4) applying population-to-Test patient specific deformation to the population model to reconstruct Test-patient specific 3D heart models. The percentage volume overlap between the NC-adapted reconstruction and actual Test patient's true heart volume was calculated using the Dice coefficient. The average Dice coefficient expressed as a percentage between the NC-adapted and actual Test model was 89.4 ± 2.8%. The modified NC adaptation

  13. 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

  14. Determination of two- and three-dimensional radiation fields for neutron radiotherapy planning

    International Nuclear Information System (INIS)

    Boehm, J.K.

    1986-01-01

    The thesis deals with the computerized investigations for fast neutron radiotherapy planning, explaining the calculation and modelling of local dose distributions in patients as a result of mixed neutron and gamma radiation fields. For a computed irradiation program (elaborated for instance by the COMRAD program system), dose distribution functions are required for the simulation of multi-field or moving beam irradiations, the functions being derived semi-empirically by non-linear regression. The necessary data on stationary field doses are derived by measurements or by computed simulation with specific transport programs from the nuclear engineering sector. Transport calculations show the effects of inhomogeneities in the patient's body on the dose distribution. The determined, strong inhomogneity effects (lungs, head) have to be taken into account as precisely as possible in order to achieve optimum irradiation planning. (orig./HP) [de

  15. Usefulness of CT-MRI fusion in radiotherapy planning for localized prostate cancer

    International Nuclear Information System (INIS)

    Tanaka, Hidekazu; Hayashi, Shinya; Ohtakara, Kazuhiro; Hoshi, Hiroaki; Iida, Takayoshi

    2011-01-01

    We compared the prostate volumes and rectal doses calculated by CT and CT-MRI fusion, and verified the usefulness of CT-MRI fusion in three-dimensional (3D) radiotherapy planning for localized prostate cancer. Three observers contoured the prostate and rectum of 13 patients with CT and CT-MRI fusion. Prostate delineations were classified into three sub-parts, and the volumes and distances to the rectum (partial response (PR) distance) were calculated. 3D radiotherapy plans were generated. A dose-volume histogram (DVH) was constructed for the rectum. The intermodality and interobserver variations were assessed. CT-MRI fusion yielded a significantly lower prostate volume by 31%. In the sub-part analysis, the greatest difference was seen for the apical side. The PR distance was significantly extended by 3.5-mm, and the greatest difference was seen for the basal side. The irradiated rectal volume was reduced in the CT-MRI fusion-based plan. The reduction rates were greater in the relatively high-dose regions. The decrease of the prostate volume and length alteration of the distance between the prostate and rectum were correlated with the decrease of the irradiated rectal volume. The prostate volume delineated by CT-MRI fusion was negatively correlated with the decrease of the irradiated rectal volume. CT showed a tendency towards overestimation of the prostate volume and underestimation of the PR distance as compared to CT-MRI fusion. The rectal dose was significantly reduced in CT-MRI fusion-based plan. Using CT-MRI fusion, especially in cases with a small prostate, the irradiated rectal volume can be reduced, with consequent reduction in rectal complications. (author)

  16. Telematics-based online client-server/client collaborative environment for radiotherapy planning simulations.

    Science.gov (United States)

    Kum, Oyeon

    2007-11-01

    Customized cancer radiation treatment planning for each patient is very useful for both a patient and a doctor because it provides the ability to deliver higher doses to a more accurately defined tumor and at the same time lower doses to organs at risk and normal tissues. This can be realized by building an accurate planning simulation system to provide better treatment strategies based on each patient's tomographic data such as CT, MRI, PET, or SPECT. In this study, we develop a real-time online client-server/client collaborative environment between the client (health care professionals or hospitals) and the server/client under a secure network using telematics (the integrated use of telecommunications and medical informatics). The implementation is based on a point-to-point communication scheme between client and server/client following the WYSIWIS (what you see is what I see) paradigm. After uploading the patient tomographic data, the client is able to collaborate with the server/client for treatment planning. Consequently, the level of health care services can be improved, specifically for small radiotherapy clinics in rural/remote-country areas that do not possess much experience or equipment such as a treatment planning simulator. The telematics service of the system can also be used to provide continued medical education in radiotherapy. Moreover, the system is easy to use. A client can use the system if s/he is familiar with the Windows(TM) operating system because it is designed and built based on a user-friendly concept. This system does not require the client to continue hardware and software maintenance and updates. These are performed automatically by the server.

  17. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    International Nuclear Information System (INIS)

    Forde, Elizabeth; Kneebone, Andrew; Bromley, Regina; Guo, Linxin; Hunt, Peter; Eade, Thomas

    2013-01-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units

  18. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Kneebone, Andrew [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia); Bromley, Regina [Institute of Medical Physics, School of Physics, University of Sydney, New South Wales (Australia); Guo, Linxin; Hunt, Peter [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Eade, Thomas [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia)

    2013-10-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units.

  19. Patient Selection and Activity Planning Guide for Selective Internal Radiotherapy With Yttrium-90 Resin Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Wan-Yee, E-mail: josephlau@surgery.cuhk.edu.hk [Faculty of Medicine, Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Kennedy, Andrew S. [Wake Radiology Oncology, Cary, NC (United States); Department of Biomedical Engineering, North Carolina State University, Raleigh, NC (United States); Kim, Yun Hwan [Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Lai, Hee Kit [Nuclear Medicine and PET Centre, Mount Elizabeth Hospital, Singapore (Singapore); Lee, Rheun-Chuan [Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Leung, Thomas W.T. [Comprehensive Oncology Centre, Hong Kong Sanatorium and Hospital (Hong Kong); Liu, Ching-Sheng [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Salem, Riad [Division of Interventional Radiology, Northwestern University, Chicago, IL (United States); Sangro, Bruno [Liver Unit, Clinica Universitaria de Navarra and Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas, Pamplona (Spain); Shuter, Borys [Department of Diagnostic Imaging, National University Hospital, Singapore (Singapore); Wang, Shih-Chang [Parker-Hughes Professor of Diagnostic Radiology, University of Sydney, Sydney, NSW (Australia)

    2012-01-01

    Purpose: Selective internal radiotherapy (SIRT) with yttrium-90 ({sup 90}Y) resin microspheres can improve the clinical outcomes for selected patients with inoperable liver cancer. This technique involves intra-arterial delivery of {beta}-emitting microspheres into hepatocellular carcinomas or liver metastases while sparing uninvolved structures. Its unique mode of action, including both {sup 90}Y brachytherapy and embolization of neoplastic microvasculature, necessitates activity planning methods specific to SIRT. Methods and Materials: A panel of clinicians experienced in {sup 90}Y resin microsphere SIRT was convened to integrate clinical experience with the published data to propose an activity planning pathway for radioembolization. Results: Accurate planning is essential to minimize potentially fatal sequelae such as radiation-induced liver disease while delivering tumoricidal {sup 90}Y activity. Planning methods have included empiric dosing according to degree of tumor involvement, empiric dosing adjusted for the body surface area, and partition model calculations using Medical Internal Radiation Dose principles. It has been recommended that at least two of these methods be compared when calculating the microsphere activity for each patient. Conclusions: Many factors inform {sup 90}Y resin microsphere SIRT activity planning, including the therapeutic intent, tissue and vasculature imaging, tumor and uninvolved liver characteristics, previous therapies, and localization of the microsphere infusion. The influence of each of these factors has been discussed.

  20. Pilot study on virtual imaging for patient information on radiotherapy planning and delivery

    International Nuclear Information System (INIS)

    Sulé-Suso, J.; Finney, S.; Bisson, J.; Hammersley, S.; Jassel, S.; Knight, R.; Hicks, C.; Sargeant, S.; Lam, K.-P.; Belcher, J.; Collins, D.; Bhana, R.; Adab, F.; O'Donovan, C.; Moloney, A.

    2015-01-01

    It is widely accepted that health professionals might sometimes underestimate cancer patients' needs for information on the complex process of radiotherapy (RT) planning and delivery. Furthermore, relatives might also feel excluded from the treatment of their loved ones. This pilot study was carried out in order to assess whether both patients and their relatives would welcome further information on RT planning and delivery using the virtual reality (VR) system VERT. One hundred and fifty patients with different types of cancer receiving radical RT were included in the study. Patients and relatives were shown using VERT on a one-to-one basis with an oncologist or a radiographer, a standard room where RT is given, a linear accelerator, and how RT is planned and delivered using their own planning CT Scans. Patients welcomed this information as it helped them to reduce their fears about RT. Relatives felt also more involved in the treatment of their loved one. The results obtained in this pilot study show that VR aids could become an important tool for delivering information on RT to both patients and relatives. - Highlights: • Virtual imaging helps patients to better understand RT planning and delivery. • Virtual imaging reduces the fear factor. • Virtual imaging improves patients and relatives satisfaction

  1. A DICOM based radiotherapy plan database for research collaboration and reporting

    Science.gov (United States)

    Westberg, J.; Krogh, S.; Brink, C.; Vogelius, I. R.

    2014-03-01

    Purpose: To create a central radiotherapy (RT) plan database for dose analysis and reporting, capable of calculating and presenting statistics on user defined patient groups. The goal is to facilitate multi-center research studies with easy and secure access to RT plans and statistics on protocol compliance. Methods: RT institutions are able to send data to the central database using DICOM communications on a secure computer network. The central system is composed of a number of DICOM servers, an SQL database and in-house developed software services to process the incoming data. A web site within the secure network allows the user to manage their submitted data. Results: The RT plan database has been developed in Microsoft .NET and users are able to send DICOM data between RT centers in Denmark. Dose-volume histogram (DVH) calculations performed by the system are comparable to those of conventional RT software. A permission system was implemented to ensure access control and easy, yet secure, data sharing across centers. The reports contain DVH statistics for structures in user defined patient groups. The system currently contains over 2200 patients in 14 collaborations. Conclusions: A central RT plan repository for use in multi-center trials and quality assurance was created. The system provides an attractive alternative to dummy runs by enabling continuous monitoring of protocol conformity and plan metrics in a trial.

  2. Evaluation of delivered dose for a clinical daily adaptive plan selection strategy for bladder cancer radiotherapy.

    Science.gov (United States)

    Lutkenhaus, Lotte J; Visser, Jorrit; de Jong, Rianne; Hulshof, Maarten C C M; Bel, Arjan

    2015-07-01

    To account for variable bladder size during bladder cancer radiotherapy, a daily plan selection strategy was implemented. The aim of this study was to calculate the actually delivered dose using an adaptive strategy, compared to a non-adaptive approach. Ten patients were treated to the bladder and lymph nodes with an adaptive full bladder strategy. Interpolated delineations of bladder and tumor on a full and empty bladder CT scan resulted in five PTVs for which VMAT plans were created. Daily cone beam CT (CBCT) scans were used for plan selection. Bowel, rectum and target volumes were delineated on these CBCTs, and delivered dose for these was calculated using both the adaptive plan, and a non-adaptive plan. Target coverage for lymph nodes improved using an adaptive strategy. The full bladder strategy spared the healthy part of the bladder from a high dose. Average bowel cavity V30Gy and V40Gy significantly reduced with 60 and 69ml, respectively (pstrategy yielded similar bladder coverage and improved coverage for lymph nodes, with a significant reduction in bowel cavity V30Gy and V40Gy only, while other sparing was limited. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning

    International Nuclear Information System (INIS)

    Sattler, Bernhard; Lee, John A.; Lonsdale, Markus; Coche, Emmanuel

    2010-01-01

    The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy. By the choice of the PET-Tracer, a variety of different metabolic processes can be visualized. First and foremost, this is the glucose metabolism of a tissue as well as for instance hypoxia or cell proliferation. This paper comprises the system characteristics of hybrid PET/CT systems. Acquisition and processing protocols are described in general and modifications to cope with the special needs in radiooncology. This starts with the different position of the patient on a special table top, continues with the use of the same fixation material as used for positioning of the patient in radiooncology while simulation and irradiation and leads to special processing protocols that include the delineation of the volumes that are subject to treatment planning and irradiation (PTV, GTV, CTV, etc.). General CT acquisition and processing parameters as well as the use of contrast enhancement of the CT are described. The possible risks and pitfalls the investigator could face during the hybrid-imaging procedure are explained and listed. The interdisciplinary use of different imaging modalities implies a increase of the volume of data created. These data need to be stored and communicated fast, safe and correct. Therefore, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and

  4. Functional Image-Guided Radiotherapy Planning in Respiratory-Gated Intensity-Modulated Radiotherapy for Lung Cancer Patients With Chronic Obstructive Pulmonary Disease

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tomoki, E-mail: tkkimura@hiroshima-u.ac.jp [Department of Radiation Oncology, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima City (Japan); Nishibuchi, Ikuno; Murakami, Yuji; Kenjo, Masahiro; Kaneyasu, Yuko; Nagata, Yasushi [Department of Radiation Oncology, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima City (Japan)

    2012-03-15

    Purpose: To investigate the incorporation of functional lung image-derived low attenuation area (LAA) based on four-dimensional computed tomography (4D-CT) into respiratory-gated intensity-modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) in treatment planning for lung cancer patients with chronic obstructive pulmonary disease (COPD). Methods and Materials: Eight lung cancer patients with COPD were the subjects of this study. LAA was generated from 4D-CT data sets according to CT values of less than than -860 Hounsfield units (HU) as a threshold. The functional lung image was defined as the area where LAA was excluded from the image of the total lung. Two respiratory-gated radiotherapy plans (70 Gy/35 fractions) were designed and compared in each patient as follows: Plan A was an anatomical IMRT or VMAT plan based on the total lung; Plan F was a functional IMRT or VMAT plan based on the functional lung. Dosimetric parameters (percentage of total lung volume irradiated with {>=}20 Gy [V20], and mean dose of total lung [MLD]) of the two plans were compared. Results: V20 was lower in Plan F than in Plan A (mean 1.5%, p = 0.025 in IMRT, mean 1.6%, p = 0.044 in VMAT) achieved by a reduction in MLD (mean 0.23 Gy, p = 0.083 in IMRT, mean 0.5 Gy, p = 0.042 in VMAT). No differences were noted in target volume coverage and organ-at-risk doses. Conclusions: Functional IGRT planning based on LAA in respiratory-guided IMRT or VMAT appears to be effective in preserving a functional lung in lung cancer patients with COPD.

  5. NOTE: Patient-specific planning for prevention of mechanical collisions during radiotherapy

    Science.gov (United States)

    Nioutsikou, Elena; Bedford, James L.; Webb, Steve

    2003-11-01

    A common unwanted difficulty in treatment planning, especially in non-coplanar radiotherapy set-ups, is the potential collision of the rotating gantry with the couch and/or the patient's body. A technique and computer program that detects these and signals avoidance of such beam directions is presented. The problem was approached using analytical geometry. The separate components within the treatment room have either been measured and modelled for an Elekta linear accelerator, or read out from a Pinnacle3 treatment planning system and are represented as an integer grid of points in three-dimensional (3D) space. The module is attached to the treatment planning system and can provide rejection or acceptance of unwanted beam directions in a plan. In contrast to previous work that has only used patient models, each individual patient's outlines are considered here in their actual treatment position inclusive of any immobilization device. The extremities of the patient superiorly and inferiorly to the scanned region are simulated by an expanded version of the RANDO phantom. In this way, 'potential' collisions can be detected in addition to the certain ones. Patient position is not a limiting factor for the accuracy of the collision detection anymore, as each set-up is always created around the isocentre. Maps of allowed and forbidden zones within the treatment suite have been created by running the code for all possible gantry and couch angles for three commonly arising cases: a head and neck plan utilizing a small stereotactic collimator, a prostate plan with multileaf collimators and an abdominal plan with the lead tray attached. In the last case, the 3D map permitted significantly fewer set-up combinations. Good agreement between prediction and experiment confirmed the capability of the program and introduces a promising add-on for treatment planning.

  6. Effectiveness of the BOOST-A™ online transition planning program for adolescents on the autism spectrum: a quasi-randomized controlled trial.

    Science.gov (United States)

    Hatfield, Megan; Falkmer, Marita; Falkmer, Torbjorn; Ciccarelli, Marina

    2017-01-01

    The majority of existing transition planning programs are focused on people with a disability in general and may not meet the specific need of adolescents on the autism spectrum. In addition, these interventions focus on specific skills (e.g. job readiness or self-determination) rather than the overall transition planning process and there are methodological limitations to many of the studies determining their effectiveness. The Better OutcOmes & Successful Transitions for Autism (BOOST-A™) is an online program that supports adolescents on the autism spectrum to prepare for leaving school. This study aimed to determine the effectiveness of the BOOST-A™ in enhancing self-determination. A quasi-randomized controlled trial was conducted with adolescents on the autism spectrum enrolled in years 8 to 11 in Australian schools (N = 94). Participants had to have basic computer skills and the ability to write at a year 5 reading level. Participants were allocated to a control (n = 45) or intervention (n = 49) group and participants were blinded to the trial hypothesis. The intervention group used the BOOST-A™ for 12 months, while the control group participated in regular practice. Outcomes included self-determination, career planning and exploration, quality of life, environmental support and domain specific self-determination. Data were collected from parents and adolescents. There were no significant differences in overall self-determination between groups. Results indicated significant differences in favor of the intervention group in three areas: opportunity for self-determination at home as reported by parents; career exploration as reported by parents and adolescents; and transition-specific self-determination as reported by parents. Results provide preliminary evidence that the BOOST-A™ can enhance some career-readiness outcomes. Lack of significant outcomes related to self-determination at school and career planning may be due to the lack of face

  7. Discrepancies between selected Pareto optimal plans and final deliverable plans in radiotherapy multi-criteria optimization.

    Science.gov (United States)

    Kyroudi, Archonteia; Petersson, Kristoffer; Ghandour, Sarah; Pachoud, Marc; Matzinger, Oscar; Ozsahin, Mahmut; Bourhis, Jean; Bochud, François; Moeckli, Raphaël

    2016-08-01

    Multi-criteria optimization provides decision makers with a range of clinical choices through Pareto plans that can be explored during real time navigation and then converted into deliverable plans. Our study shows that dosimetric differences can arise between the two steps, which could compromise the clinical choices made during navigation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Differences among doses for neuro-axis radiotherapy planning in the gonadal region

    International Nuclear Information System (INIS)

    Lima, F.F de; Vilela, E.C.; Oliveira, F.L.; Filho, J.A.

    2015-01-01

    Radiotherapy can disrupt the functioning of the hypothalamic-pituitary axis, directly causing ovarian deficiencies, such as the decrease in fertility or damage that renders the uterus incapable of accommodating the growth of a fetus. However, these issues have become increasingly important to a growing number of pediatric and adolescent cancer survivors. The whole-body, cranial-spinal axis, as well as abdomen and pelvic region irradiations may expose the ovaries to radiation and may cause premature ovarian failure, whereas doses above 35 Gy cranial can affect the hypothalamic-pituitary functions. This study performed a comparison of four doses of radiotherapy planning techniques for the neural axis. For this analysis, technical simulations were performed for the treatment of medulloblastoma in four different planning, applied in a RANDO anthropomorphic phantom and dosimeters (TLD-100). The radiation fields in the 1”st and 2”nd planning were 40 x 5 cm”2 and 17 x 5 cm”2 with 4.0 cm depth, in which doses were 0.03 and 0.05 Gy / day and 0.11 and 0.09 Gy / days, on the right and left sides, respectively. The 3”rd and 4”th measured planning 32 x 7 cm”2 and 18 x 7 cm”2, with a 2 cm gap and a 4.0 and 5.0 cm depth, in which doses were 1.08 and 0.2 Gy/day and 1.14 and 0.14 Gy/day, on the left and right sides, respectively. It could be observed that the doses in the ovaries in the 3”rd and 4”th schedules proved to be larger than the doses in the 1 s t and 2 n d planning. This is caused by the spinal field width and the depth of the second spinal field, which is 1.0 cm more than the field of the 1”st and 2”nd planning. These differences should be observed in image planning, as incorrect measures can cause damage in the treatment finish. (authors)

  9. The Impact of Colleague Peer Review on the Radiotherapy Treatment Planning Process in the Radical Treatment of Lung Cancer.

    Science.gov (United States)

    Rooney, K P; McAleese, J; Crockett, C; Harney, J; Eakin, R L; Young, V A L; Dunn, M A; Johnston, R E; Hanna, G G

    2015-09-01

    Modern radiotherapy uses techniques to reliably identify tumour and reduce target volume margins. However, this can potentially lead to an increased risk of geographic miss. One source of error is the accuracy of target volume delineation (TVD). Colleague peer review (CPR) of all curative-intent lung cancer plans has been mandatory in our institution since May 2013. At least two clinical oncologists review plans, checking treatment paradigm, TVD, prescription dose tumour and critical organ tolerances. We report the impact of CPR in our institution. Radiotherapy treatment plans of all patients receiving radical radiotherapy were presented at weekly CPR meetings after their target volumes were reviewed and signed off by the treating consultant. All cases and any resultant change to TVD (including organs at risk) or treatment intent were recorded in our prospective CPR database. The impact of CPR over a 13 month period from May 2013 to June 2014 is reported. One hundred and twenty-two patients (63% non-small cell lung carcinoma, 17% small cell lung carcinoma and 20% 'clinical diagnosis') were analysed. On average, 3.2 cases were discussed per meeting (range 1-8). CPR resulted in a change in treatment paradigm in 3% (one patient proceeded to induction chemotherapy, two patients had high-dose palliative radiotherapy). Twenty-one (17%) had a change in TVD and one (1%) patient had a change in dose prescription. In total, 6% of patients had plan adjustment after review of dose volume histogram. The introduction of CPR in our centre has resulted in a change in a component of the treatment plan for 27% of patients receiving curative-intent lung radiotherapy. We recommend CPR as a mandatory quality assurance step in the planning process of all radical lung plans. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  10. Influence of FDG-PET on computed tomography-based radiotherapy planning for locally recurrent nasopharyngeal carcinoma.

    Science.gov (United States)

    Zheng, Xiao-Kang; Chen, Long-Hua; Wang, Quan-Shi; Wu, Hu-Bing; Wang, Hong-Mei; Chen, Yong-Qin; Yan, Wei-Pin; Li, Qi-Sheng; Xu, Yi-Kai

    2007-12-01

    Assuming F-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET)/computed tomography (CT) to be more accurate in representing the true disease extent than CT alone, we prospectively designed this study to evaluate how the addition of FDG-PET influences CT-based radiotherapy planning for locally recurrent nasopharyngeal carcinoma. All patients underwent FDG-PET/CT simulation scans. For each patient, the gross tumor volume (GTV) was separately delineated with or without the addition of PET information and defined as GTV PET/CT and GTV CT, respectively. Corresponding planning target volumes (PTV) were generated for the GTV CT (PTV(CT)) and GTV PET/CT (PTV PET/CT). Three-dimensional conformal radiotherapy plans were separately created for PTV CT and PTV PET/CT. To assess the potential geographic miss of the PET/CT-based disease in CT-based treatment planning, the size and location of the GTV PET/CT, PTV(PET/CT), and PTV(CT) were analyzed, and the three-dimensional conformal radiotherapy plans created using the PTV CT were evaluated with the GTV PET/CT and PTV PET/CT information. A total of 43 patients were enrolled in this study. Distant metastasis was found in 4 patients with the addition of the PET information. The 39 patients without distant metastasis proceeded to three-dimensional conformal radiotherapy planning. Inadequate coverage of the GTV PET/CT and PTV PET/CT by the PTV CT occurred in 7 (18%) and 20 (51%) patients, respectively. This resulted in or=95% of the prescribed dose in 4 (10%) and 13 (33%) patients, respectively. The addition of FDG-PET information might influence CT-based radiotherapy planning for locally recurrent nasopharyngeal carcinoma by altering the definition of the target volume, with the potential to avoid a geographic miss of true disease.

  11. A dose-volume histogram based decision-support system for dosimetric comparison of radiotherapy treatment plans

    International Nuclear Information System (INIS)

    Alfonso, J. C. L.; Herrero, M. A.; Núñez, L.

    2015-01-01

    The choice of any radiotherapy treatment plan is usually made after the evaluation of a few preliminary isodose distributions obtained from different beam configurations. Despite considerable advances in planning techniques, such final decision remains a challenging task that would greatly benefit from efficient and reliable assessment tools. For any dosimetric plan considered, data on dose-volume histograms supplied by treatment planning systems are used to provide estimates on planning target coverage as well as on sparing of organs at risk and the remaining healthy tissue. These partial metrics are then combined into a dose distribution index (DDI), which provides a unified, easy-to-read score for each competing radiotherapy plan. To assess the performance of the proposed scoring system, DDI figures for fifty brain cancer patients were retrospectively evaluated. Patients were divided in three groups depending on tumor location and malignancy. For each patient, three tentative plans were designed and recorded during planning, one of which was eventually selected for treatment. We thus were able to compare the plans with better DDI scores and those actually delivered. When planning target coverage and organs at risk sparing are considered as equally important, the tentative plan with the highest DDI score is shown to coincide with that actually delivered in 32 of the 50 patients considered. In 15 (respectively 3) of the remaining 18 cases, the plan with highest DDI value still coincides with that actually selected, provided that organs at risk sparing is given higher priority (respectively, lower priority) than target coverage. DDI provides a straightforward and non-subjective tool for dosimetric comparison of tentative radiotherapy plans. In particular, DDI readily quantifies differences among competing plans with similar-looking dose-volume histograms and can be easily implemented for any tumor type and localization, irrespective of the planning system and

  12. Small animal radiotherapy research platforms

    International Nuclear Information System (INIS)

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-01-01

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  13. Small animal radiotherapy research platforms

    Energy Technology Data Exchange (ETDEWEB)

    Verhaegen, Frank; Granton, Patrick [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Tryggestad, Erik, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States)

    2011-06-21

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  14. Quality control in health care: an experiment in radiotherapy planning for breast cancer patients after mastectomy

    International Nuclear Information System (INIS)

    Holli, Kaija; Laippala, Pekka; Ojala, Antti; Pitkaenen, Maunu

    1999-01-01

    Purpose: The importance of evaluating and improving quality in clinical practice is now generally acknowledged. In this study we estimated different sources of variation in radiotherapy planning for breast cancer patients after mastectomy and sought to test the applicability of a reproducibility and repeatability (R and R) study in a clinical context. Methods: Eleven radiation oncologists planned radiotherapy three times for three different kinds of breast cancer patients without knowing they were handling the same patient three times. Variation was divided into different components: physicians as operators, patients as parts, and repeated measurements as trials. Variation due to difference across trials (repeatability), that across the physicians (reproducibility), and that across the patients (variability) were estimated, as well as interactions between physicians and patients. Calculation was based on the sum of squares, and analysis was supported by various graphical presentations such as range charts and box plots. Results: Some parts of the planning process were characterized by higher and different kinds of variation than the others. Interphysician variation (i.e., reproducibility) was not high but there were some clearly outlying physicians. The highest variation was in repeatability (intraphysician variation). The major part of the variation was, however, that from patient to patient: 33% of the total in Parameter 1 and 85% of the total in Parameter 2. Conclusions: R and R studies are applicable and are needed to evaluate and improve quality in clinical practice. This kind of analysis provides opportunities to establish which kinds of patients require particularly careful attention, which points in the process are most critical for variation, which are the most difficult aspects for each physician and call for more careful description in documents, and which physicians need further training

  15. (18) F-FDG PET/CT for planning external beam radiotherapy alters therapy in 11% of 581 patients

    DEFF Research Database (Denmark)

    Birk Christensen, Charlotte; Loft-Jakobsen, Annika; Munck Af Rosenschöld, Per

    2018-01-01

    of the radiotherapy planning. 'A major change of treatment strategy' was defined as either including more lesions in the gross tumour volume (GTV) distant from the primary tumour or a change in treatment modalities. METHODS: The study includes 581 consecutive patients who underwent an FDG PET/CT scan for radiotherapy...... GTV (GTV-PET). RESULTS: For 63 of the patients (11%), the PET/CT simulation scans resulted in a major change in treatment strategy because of the additional diagnostic information. Changes were most frequently observed in patients with lung cancer (20%) or upper gastrointestinal cancer (12%). In 65......BACKGROUND: (18) F-FDG PET/CT (FDG PET/CT) used in radiotherapy planning for extra-cerebral malignancy may reveal metastases to distant sites that may affect the choice of therapy. AIM: To investigate the role of FDG PET/CT on treatment strategy changes induced by the use of PET/CT as part...

  16. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs.

    Science.gov (United States)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Graves, Yan Jiang; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-21

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  17. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

    Science.gov (United States)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Jiang Graves, Yan; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-01

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  18. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

    International Nuclear Information System (INIS)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Graves, Yan Jiang; Gautier, Quentin; Mell, Loren; Jia, Xun; Jiang, Steve; Zhou, Linghong

    2013-01-01

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose–volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30

  19. 18 F-FDG PET/CT for planning external beam radiotherapy alters therapy in 11% of 581 patients.

    Science.gov (United States)

    Birk Christensen, Charlotte; Loft-Jakobsen, Annika; Munck Af Rosenschöld, Per; Højgaard, Liselotte; Roed, Henrik; Berthelsen, Anne K

    2018-03-01

    18 F-FDG PET/CT (FDG PET/CT) used in radiotherapy planning for extra-cerebral malignancy may reveal metastases to distant sites that may affect the choice of therapy. To investigate the role of FDG PET/CT on treatment strategy changes induced by the use of PET/CT as part of the radiotherapy planning. 'A major change of treatment strategy' was defined as either including more lesions in the gross tumour volume (GTV) distant from the primary tumour or a change in treatment modalities. The study includes 581 consecutive patients who underwent an FDG PET/CT scan for radiotherapy planning in our institution in the year 2008. All PET/CT scans were performed with the patient in treatment position with the use of immobilization devices according to the intended radiotherapy treatment. All scans were evaluated by a nuclear medicine physician together with a radiologist to delineate PET-positive GTV (GTV-PET). For 63 of the patients (11%), the PET/CT simulation scans resulted in a major change in treatment strategy because of the additional diagnostic information. Changes were most frequently observed in patients with lung cancer (20%) or upper gastrointestinal cancer (12%). In 65% of the patients for whom the PET/CT simulation scan revealed unexpected dissemination, radiotherapy was given - changed (n = 38) or unchanged (n = 13) according to the findings on the FDG PET/CT. Unexpected dissemination on the FDG PET/CT scanning performed for radiotherapy planning caused a change in treatment strategy in 11% of 581 patients. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  20. A method for generating large datasets of organ geometries for radiotherapy treatment planning studies

    International Nuclear Information System (INIS)

    Hu, Nan; Cerviño, Laura; Segars, Paul; Lewis, John; Shan, Jinlu; Jiang, Steve; Zheng, Xiaolin; Wang, Ge

    2014-01-01

    With the rapidly increasing application of adaptive radiotherapy, large datasets of organ geometries based on the patient’s anatomy are desired to support clinical application or research work, such as image segmentation, re-planning, and organ deformation analysis. Sometimes only limited datasets are available in clinical practice. In this study, we propose a new method to generate large datasets of organ geometries to be utilized in adaptive radiotherapy. Given a training dataset of organ shapes derived from daily cone-beam CT, we align them into a common coordinate frame and select one of the training surfaces as reference surface. A statistical shape model of organs was constructed, based on the establishment of point correspondence between surfaces and non-uniform rational B-spline (NURBS) representation. A principal component analysis is performed on the sampled surface points to capture the major variation modes of each organ. A set of principal components and their respective coefficients, which represent organ surface deformation, were obtained, and a statistical analysis of the coefficients was performed. New sets of statistically equivalent coefficients can be constructed and assigned to the principal components, resulting in a larger geometry dataset for the patient’s organs. These generated organ geometries are realistic and statistically representative

  1. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes.

    Science.gov (United States)

    Sánchez-Parcerisa, D; Kondrla, M; Shaindlin, A; Carabe, A

    2014-12-07

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa's most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator.

  2. Pelvic Radiotherapy for Cancer of the Cervix: Is What You Plan Actually What You Deliver?

    International Nuclear Information System (INIS)

    Lim, Karen; Kelly, Valerie; Stewart, James; Xie, Jason; Cho, Young-Bin; Moseley, Joanne B.; Brock, Kristy; Fyles, Anthony; Lundin, Anna; Rehbinder, Henrik; Milosevic, Michael

    2009-01-01

    Purpose: Whole pelvic intensity-modulated radiotherapy (IMRT) is increasingly being used to treat cervix cancer and other gynecologic tumors. However, tumor and normal organ movement during treatment can substantially detract from the benefits of this approach. This study explored the effect of internal anatomic changes on the dose delivered to the tumor and organs at risk using a strategy integrating deformable soft-tissue modeling with simulated dose accumulation. Methods and Materials: Twenty patients with cervix cancer underwent baseline and weekly pelvic magnetic resonance imaging during treatment. Interfraction organ motion and delivered (accumulated) dose was modeled for three treatment scenarios: four-field box, large-margin whole pelvic IMRT (20-mm planning target volume, but 10 mm inferiorly) and small-margin IMRT (5-mm planning target volume). Results: Individually, the planned dose was not the same as the simulated delivered dose; however, when taken as a group, this was not statistically significant for the four-field box and large-margin IMRT plans. The small-margin IMRT plans yielded adequate target coverage in most patients; however, significant target underdosing occurred in 1 patient who displayed excessive, unpredictable internal target movement. The delivered doses to the organs at risk were significantly reduced with the small-margin plan, although substantial variability was present among the patients. Conclusion: Simulated dose accumulation might provide a more accurate depiction of the target and organ at risk coverage during fractionated whole pelvic IMRT for cervical cancer. The adequacy of primary tumor coverage using 5-mm planning target volume margins is contingent on the use of daily image-guided setup.

  3. Auditing local methods for quality assurance in radiotherapy using the same set of predefined treatment plans

    Directory of Open Access Journals (Sweden)

    Enrica Seravalli

    2018-01-01

    Full Text Available Background and purpose: Local implementation of plan-specific quality assurance (QA methods for intensity-modulated radiotherapy (IMRT and volumetric modulated arc therapy (VMAT treatment plans may vary because of dissimilarities in procedures, equipment and software. The purpose of this work is detecting possible differences between local QA findings and those of an audit, using the same set of treatment plans. Methods: A pre-defined set of clinical plans was devised and imported in the participating institute’s treatment planning system for dose computation. The dose distribution was measured using an ionisation chamber, radiochromic film and an ionisation chamber array. The centres performed their own QA, which was compared to the audit findings. The agreement/disagreement between the audit and the institute QA results were assessed along with the differences between the dose distributions measured by the audit team and computed by the institute. Results: For the majority of the cases the results of the audit were in agreement with the institute QA findings: ionisation chamber: 92%, array: 88%, film: 76% of the total measurements. In only a few of these cases the evaluated measurements failed for both: ionisation chamber: 2%, array: 4%, film: 0% of the total measurements. Conclusion: Using predefined treatment plans, we found that in approximately 80% of the evaluated measurements the results of local QA of IMRT and VMAT plans were in line with the findings of the audit. However, the percentage of agreement/disagreement depended on the characteristics of the measurement equipment used and on the analysis metric. Keywords: Quality assurance, Dosimetry audit, IMRT, VMAT, QA devices

  4. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes

    Science.gov (United States)

    Sánchez-Parcerisa, D.; Kondrla, M.; Shaindlin, A.; Carabe, A.

    2014-12-01

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa’s most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator.

  5. Treatment planning for heavy ion radiotherapy: physical beam model and dose optimization

    International Nuclear Information System (INIS)

    Kraemer, M.; Haberer, T.; Kraft, G.; Schardt, D.; Weber, U.

    2000-09-01

    We describe a novel code system, TRiP, dedicated to the planning of radiotherapy with energetic ions, in particular 12 C. The software is designed to cooperate with three-dimensional active dose shaping devices like the GSI raster scan system. This unique beam delivery system allows to select any combination from a list of 253 individual beam energies, 7 different beam spot sizes and 15 intensity levels. The software includes a beam model adapted to and verified for carbon ions. Inverse planning techniques are implemented in order to obtain a uniform target dose distribution from clinical input data, i.e. CT images and patient contours. This implies the automatic generation of intensity modulated fields of heavy ions with as many as 40000 raster points, where each point corresponds to a specific beam position, energy and particle fluence. This set of data is directly passed to the beam delivery and control system. The treatment planning code is in clinical use since the start of the GSI pilot project in December 1997. To this end 48 patients have been successfully planned and treated. (orig.)

  6. Reduction of computational dimensionality in inverse radiotherapy planning using sparse matrix operations

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Paul S. [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195-6043 (United States)]. E-mail: cho@radonc.washington.edu; Phillips, Mark H. [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195-6043 (United States)

    2001-05-01

    For dynamic multileaf collimator-based intensity modulated radiotherapy in which small beam elements are used to generate continuous modulation, the sheer size of the dose calculation matrix could pose serious computational challenges. In order to circumvent this problem, the dose calculation matrix was reduced to a sparse matrix by truncating the weakly contributing entries below a certain cutoff to zero. Subsequently, the sparse matrix was compressed and matrix indexing vectors were generated to facilitate matrix-vector and matrix-matrix operations used in inverse planning. The application of sparsity permitted the reduction of overall memory requirement by an order of magnitude. In addition, the effect of disregarding the small scatter components on the quality of optimization was investigated by repeating the inverse planning using the dense dose calculation matrix. Comparison of dense and sparse matrix-based plans revealed an insignificant difference in optimization outcome, thus demonstrating the feasibility and usefulness of the sparse method in inverse planning. Furthermore, two additional methods of memory minimization are suggested, namely hexagonal dose sampling and limited normal tissue sampling. (author)

  7. Reduction of computational dimensionality in inverse radiotherapy planning using sparse matrix operations.

    Science.gov (United States)

    Cho, P S; Phillips, M H

    2001-05-01

    For dynamic multileaf collimator-based intensity modulated radiotherapy in which small beam elements are used to generate continuous modulation, the sheer size of the dose calculation matrix could pose serious computational challenges. In order to circumvent this problem, the dose calculation matrix was reduced to a sparse matrix by truncating the weakly contributing entries below a certain cutoff to zero. Subsequently, the sparse matrix was compressed and matrix indexing vectors were generated to facilitate matrix-vector and matrix-matrix operations used in inverse planning. The application of sparsity permitted the reduction of overall memory requirement by an order of magnitude. In addition, the effect of disregarding the small scatter components on the quality of optimization was investigated by repeating the inverse planning using the dense dose calculation matrix. Comparison of dense and sparse matrix-based plans revealed an insignificant difference in optimization outcome, thus demonstrating the feasibility and usefulness of the sparse method in inverse planning. Furthermore, two additional methods of memory minimization are suggested, namely hexagonal dose sampling and limited normal tissue sampling.

  8. NOTE: Reduction of computational dimensionality in inverse radiotherapy planning using sparse matrix operations

    Science.gov (United States)

    Cho, Paul S.; Phillips, Mark H.

    2001-05-01

    For dynamic multileaf collimator-based intensity modulated radiotherapy in which small beam elements are used to generate continuous modulation, the sheer size of the dose calculation matrix could pose serious computational challenges. In order to circumvent this problem, the dose calculation matrix was reduced to a sparse matrix by truncating the weakly contributing entries below a certain cutoff to zero. Subsequently, the sparse matrix was compressed and matrix indexing vectors were generated to facilitate matrix-vector and matrix-matrix operations used in inverse planning. The application of sparsity permitted the reduction of overall memory requirement by an order of magnitude. In addition, the effect of disregarding the small scatter components on the quality of optimization was investigated by repeating the inverse planning using the dense dose calculation matrix. Comparison of dense and sparse matrix-based plans revealed an insignificant difference in optimization outcome, thus demonstrating the feasibility and usefulness of the sparse method in inverse planning. Furthermore, two additional methods of memory minimization are suggested, namely hexagonal dose sampling and limited normal tissue sampling.

  9. Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

    2016-01-01

    To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1–2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85–6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins.

  10. Treatment planning for heavy-ion radiotherapy: physical beam model and dose optimization

    Science.gov (United States)

    Krämer, M.; Jäkel, O.; Haberer, T.; Kraft, G.; Schardt, D.; Weber, U.

    2000-11-01

    We describe a novel code system, TRiP, dedicated to the planning of radiotherapy with energetic ions, in particular 12C. The software is designed to cooperate with three-dimensional active dose shaping devices like the GSI raster scan system. This unique beam delivery system allows us to select any combination from a list of 253 individual beam energies, 7 different beam spot sizes and 15 intensity levels. The software includes a beam model adapted to and verified for carbon ions. Inverse planning techniques are implemented in order to obtain a uniform target dose distribution from clinical input data, i.e. CT images and patient contours. This implies the automatic generation of intensity modulated fields of heavy ions with as many as 40 000 raster points, where each point corresponds to a specific beam position, energy and particle fluence. This set of data is directly passed to the beam delivery and control system. The treatment planning code has been in clinical use since the start of the GSI pilot project in December 1997. Forty-eight patients have been successfully planned and treated.

  11. MMCTP: a radiotherapy research environment for Monte Carlo and patient-specific treatment planning

    International Nuclear Information System (INIS)

    Alexander, A; DeBlois, F; Stroian, G; Al-Yahya, K; Heath, E; Seuntjens, J

    2007-01-01

    Radiotherapy research lacks a flexible computational research environment for Monte Carlo (MC) and patient-specific treatment planning. The purpose of this study was to develop a flexible software package on low-cost hardware with the aim of integrating new patient-specific treatment planning with MC dose calculations suitable for large-scale prospective and retrospective treatment planning studies. We designed the software package 'McGill Monte Carlo treatment planning' (MMCTP) for the research development of MC and patient-specific treatment planning. The MMCTP design consists of a graphical user interface (GUI), which runs on a simple workstation connected through standard secure-shell protocol to a cluster for lengthy MC calculations. Treatment planning information (e.g., images, structures, beam geometry properties and dose distributions) is converted into a convenient MMCTP local file storage format designated, the McGill RT format. MMCTP features include (a) DICOM R T, RTOG and CADPlan CART format imports; (b) 2D and 3D visualization views for images, structure contours, and dose distributions; (c) contouring tools; (d) DVH analysis, and dose matrix comparison tools; (e) external beam editing; (f) MC transport calculation from beam source to patient geometry for photon and electron beams. The MC input files, which are prepared from the beam geometry properties and patient information (e.g., images and structure contours), are uploaded and run on a cluster using shell commands controlled from the MMCTP GUI. The visualization, dose matrix operation and DVH tools offer extensive options for plan analysis and comparison between MC plans and plans imported from commercial treatment planning systems. The MMCTP GUI provides a flexible research platform for the development of patient-specific MC treatment planning for photon and electron external beam radiation therapy. The impact of this tool lies in the fact that it allows for systematic, platform

  12. Evaluation of the perturbation of the mesh Bra Breast TiLoop in the planning process-radiotherapy

    International Nuclear Information System (INIS)

    Camacho, C.; Pujades, M. C.; Perez-Calatayud, J.; Lliso, F.; Carmona, V.; Richart, J.; Ballester, F.

    2011-01-01

    The aim of this study is to determine the dosimetric impact TiLoop Mesh Bra breast radiotherapy treatments, and their influence on both the quality and the disruption of the gray levels of the radiographic image required for treatment planning.

  13. Patterns of Failure and Local Control After Intraoperative Electron Boost Radiotherapy to the Presacral Space in Combination with Total Mesorectal Excision in Patients with Locally Advanced Rectal Cancer

    International Nuclear Information System (INIS)

    Roeder, Falk; Treiber, Martina; Oertel, Susanne; Dinkel, Julien; Timke, Carmen; Funk, Angela; Garcia-Huttenlocher, Helena; Bischof, Marc; Weitz, Juergen; Harms, Wolfgang; Hensley, Frank W.; Buchler, Markus W.; Debus, Juergen; Krempien, Robert

    2007-01-01

    Purpose: To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition. Methods and Materials: We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.4 Gy), and in 88% simultaneous chemotherapy was applied. Median follow-up was 59 months. Results: Local failure was observed in 17 patients (7%), resulting in a 5-year local control rate of 92%. Only complete resection and absence of nodal involvement correlated positively with local control. Considering IOERT fields, seven infield recurrences were seen in the presacral space, resulting in a 5-year local control rate of 97%. The remaining local relapses were located as follows: retrovesical/retroprostatic (5), anastomotic site (2), promontorium (1), ileocecal (1), and perineal (1). Conclusion: Intraoperative electron beam radiotherapy as part of a multimodal treatment approach including TME is a highly effective regimen to prevent local failure. The presacral space remains the site of highest risk for local failure, but IOERT can decrease the percentage of relapses in this area

  14. Magnetic resonance imaging for radiotherapy planning of brain cancer patients using immobilization and surface coils

    Science.gov (United States)

    Hanvey, S.; Glegg, M.; Foster, J.

    2009-09-01

    This study investigated the compatibility of a head and neck immobilization device with magnetic resonance imaging (MRI). The immobilization device is used to position a patient in the same way as when receiving a computed tomography (CT) scan for radiotherapy planning and radiation treatment. The advantage of using immobilization in MR is improved accuracy in CT/MR image registration enabling greater confidence in the delineation of structures. The main practical difficulty in using an immobilization device in MRI is that physical constraints make their use incompatible with head imaging coils. Within this paper we describe a method for MR imaging of the brain which allows the use of head and neck immobilization devices. By a series of image quality tests we obtained the same or better image quality as a multi-channel head coil.

  15. Comparison of three concomitant boost techniques for early-stage breast cancer

    International Nuclear Information System (INIS)

    Horton, Janet K.; Halle, Jan S.; Chang, Sha X.; Sartor, Carolyn I.

    2006-01-01

    Purpose: Whole breast radiotherapy (RT) followed by a tumor bed boost typically spans 5-6 weeks of treatment. Interest is growing in RT regimens, such as concomitant boost, that decrease overall treatment time, lessening the time/cost burden to patients and facilities. Methods and Materials: Computed tomography (CT) scans from 20 cases were selected for this retrospective, dosimetric study to compare three different techniques of concomitant boost delivery: (1) standard tangents plus an electron boost (2) intensity-modulated RT (IMRT) tangents using custom compensators plus an electron boost, and (3) IMRT tangents plus a conformal photon boost. The equivalent uniform dose model was used to compare the plans. Results: The average breast equivalent uniform dose value for the three techniques (standard, IMRT plus electrons, and IMRT plus photons) was 48.6, 47.9, and 48.3, respectively. The plans using IMRT more closely approximated the prescribed dose of 46 Gy to the whole breast. The breast volume receiving >110% of the dose was less with the IMRT tangents than with standard RT (p 0.037), but no significant difference in the maximal dose or other evaluated parameters was noted. Conclusion: Although the IMRT techniques delivered the prescribed dose with better dose uniformity, the small improvement seen did not support a goal of improved resource use

  16. Radiotherapy planning for glioblastoma based on a tumor growth model: implications for spatial dose redistribution

    International Nuclear Information System (INIS)

    Unkelbach, Jan; Dittmann, Florian; Shih, Helen A; Menze, Bjoern H; Ayache, Nicholas; Konukoglu, Ender

    2014-01-01

    Gliomas differ from many other tumors as they grow infiltratively into the brain parenchyma rather than forming a solid tumor mass with a well-defined boundary. Tumor cells can be found several centimeters away from the central tumor mass that is visible using current imaging techniques. The infiltrative growth characteristics of gliomas question the concept of a radiotherapy target volume that is irradiated to a homogeneous dose—the standard in current clinical practice. We discuss the use of the Fisher–Kolmogorov glioma growth model in radiotherapy treatment planning. The phenomenological tumor growth model assumes that tumor cells proliferate locally and migrate into neighboring brain tissue, which is mathematically described via a partial differential equation for the spatio-temporal evolution of the tumor cell density. In this model, the tumor cell density drops approximately exponentially with distance from the visible gross tumor volume, which is quantified by the infiltration length, a parameter describing the distance at which the tumor cell density drops by a factor of e. This paper discusses the implications for the prescribed dose distribution in the periphery of the tumor. In the context of the exponential cell kill model, an exponential fall-off of the cell density suggests a linear fall-off of the prescription dose with distance. We introduce the dose fall-off rate, which quantifies the steepness of the prescription dose fall-off in units of Gy mm −1 . It is shown that the dose fall-off rate is given by the inverse of the product of radiosensitivity and infiltration length. For an infiltration length of 3 mm and a surviving fraction of 50% at 2 Gy, this suggests a dose fall-off of approximately 1 Gy mm −1 . The concept is illustrated for two glioblastoma patients by optimizing intensity-modulated radiotherapy plans. The dose fall-off rate concept reflects the idea that infiltrating gliomas lack a defined boundary and are characterized by a

  17. SU-F-T-80: A Mobile Application for Intra-Operative Electron Radiotherapy Treatment Planning

    International Nuclear Information System (INIS)

    Williams, C; Crowley, E; Wolfgang, J

    2016-01-01

    Purpose: Intraoperative electron radiotherapy (IORT) poses a unique set of challenges for treatment planning. Planning must be performed in a busy operating room environment over a short timeframe often with little advance knowledge of the treatment depth or applicator size. Furthermore, IORT accelerators can have a large number of possible applicators, requiring extensive databooks that must be searched for the appropriate dosimetric parameters. The goal of this work is to develop a software tool to assist in the planning process that is suited to the challenges faced in the IORT environment. Methods: We developed a mobile application using HTML5 and Javascript that can be deployed to tablet devices suitable for use in the operating room. The user selects the desired treatment parameters cone diameter, bevel angle, and energy (a total of 141 datasets) and desired bolus. The application generates an interactive display that allows the user to dynamically select points on the depth-dose curve and to visualize the shape of the corresponding isodose contours. The user can indicate a prescription isodose line or depth. The software performs a monitor unit calculation and generates a PDF report. Results: We present our application, which is now used routinely in our IORT practice. It has been employed successfully in over 23 cases. The interactivity of the isodose distributions was found to be of particular use to physicians who are less-frequent IORT users, as well as for the education of residents and trainees. Conclusion: This software has served as a useful tool in IORT planning, and demonstrates the need for treatment planning tools that are designed for the specialized challenges encountered in IORT. This software is the subject of a license agreement with the IntraOp Medical Corporation. This software is the subject of a license agreement between Massachusetts General Hospital / Partners Healthcare and the IntraOp Medical Corporation. CLW is consulting on

  18. SU-F-T-80: A Mobile Application for Intra-Operative Electron Radiotherapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C [Brigham and Women’s Hospital & Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Crowley, E; Wolfgang, J [Harvard Medical School, Boston, MA (United States); Massachusetts General Hospital, Boston, MA (United States)

    2016-06-15

    Purpose: Intraoperative electron radiotherapy (IORT) poses a unique set of challenges for treatment planning. Planning must be performed in a busy operating room environment over a short timeframe often with little advance knowledge of the treatment depth or applicator size. Furthermore, IORT accelerators can have a large number of possible applicators, requiring extensive databooks that must be searched for the appropriate dosimetric parameters. The goal of this work is to develop a software tool to assist in the planning process that is suited to the challenges faced in the IORT environment. Methods: We developed a mobile application using HTML5 and Javascript that can be deployed to tablet devices suitable for use in the operating room. The user selects the desired treatment parameters cone diameter, bevel angle, and energy (a total of 141 datasets) and desired bolus. The application generates an interactive display that allows the user to dynamically select points on the depth-dose curve and to visualize the shape of the corresponding isodose contours. The user can indicate a prescription isodose line or depth. The software performs a monitor unit calculation and generates a PDF report. Results: We present our application, which is now used routinely in our IORT practice. It has been employed successfully in over 23 cases. The interactivity of the isodose distributions was found to be of particular use to physicians who are less-frequent IORT users, as well as for the education of residents and trainees. Conclusion: This software has served as a useful tool in IORT planning, and demonstrates the need for treatment planning tools that are designed for the specialized challenges encountered in IORT. This software is the subject of a license agreement with the IntraOp Medical Corporation. This software is the subject of a license agreement between Massachusetts General Hospital / Partners Healthcare and the IntraOp Medical Corporation. CLW is consulting on

  19. Technical Note: MRI only prostate radiotherapy planning using the statistical decomposition algorithm

    International Nuclear Information System (INIS)

    Siversson, Carl; Nordström, Fredrik; Nilsson, Terese; Nyholm, Tufve; Jonsson, Joakim; Gunnlaugsson, Adalsteinn; Olsson, Lars E.

    2015-01-01

    Purpose: In order to enable a magnetic resonance imaging (MRI) only workflow in radiotherapy treatment planning, methods are required for generating Hounsfield unit (HU) maps (i.e., synthetic computed tomography, sCT) for dose calculations, directly from MRI. The Statistical Decomposition Algorithm (SDA) is a method for automatically generating sCT images from a single MR image volume, based on automatic tissue classification in combination with a model trained using a multimodal template material. This study compares dose calculations between sCT generated by the SDA and conventional CT in the male pelvic region. Methods: The study comprised ten prostate cancer patients, for whom a 3D T2 weighted MRI and a conventional planning CT were acquired. For each patient, sCT images were generated from the acquired MRI using the SDA. In order to decouple the effect of variations in patient geometry between imaging modalities from the effect of uncertainties in the SDA, the conventional CT was nonrigidly registered to the MRI to assure that their geometries were well aligned. For each patient, a volumetric modulated arc therapy plan was created for the registered CT (rCT) and recalculated for both the sCT and the conventional CT. The results were evaluated using several methods, including mean average error (MAE), a set of dose-volume histogram parameters, and a restrictive gamma criterion (2% local dose/1 mm). Results: The MAE within the body contour was 36.5 ± 4.1 (1 s.d.) HU between sCT and rCT. Average mean absorbed dose difference to target was 0.0% ± 0.2% (1 s.d.) between sCT and rCT, whereas it was −0.3% ± 0.3% (1 s.d.) between CT and rCT. The average gamma pass rate was 99.9% for sCT vs rCT, whereas it was 90.3% for CT vs rCT. Conclusions: The SDA enables a highly accurate MRI only workflow in prostate radiotherapy planning. The dosimetric uncertainties originating from the SDA appear negligible and are notably lower than the uncertainties

  20. A multi-institutional study to assess adherence to lung stereotactic body radiotherapy planning goals

    International Nuclear Information System (INIS)

    Woerner, Andrew; Roeske, John C.; Harkenrider, Matthew M.; Campana, Maria; Surucu, Murat; Fan, John; Aydogan, Bulent; Koshy, Matthew; Laureckas, Robert; Vali, Faisal

    2015-01-01

    Purpose: A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. Methods: A total of 300 patients receiving lung SBRT treatments in four different institutions were retrospectively reviewed. The treatments were delivered using Linac based SBRT (160 patients) or image guided robotic radiosurgery (140). Most tumors were located peripherally (250/300). Median fractional doses and ranges were 18 Gy (8–20 Gy), 12 Gy (6–15 Gy), and 10 Gy (5–12 Gy) for three, four, and five fraction treatments, respectively. The following planning criteria derived from RTOG trials and the literature were used to evaluate the treatment plans: planning target volumes, PTV V 100 ≥ 95% and PTV V 95 ≥ 99%; conformality indices, CI 100% < 1.2 and CI 50% range of 2.9–5.9 dependent on PTV; total lung-ITV: V 20Gy < 10%, V 12.5Gy < 15%, and V 5Gy < 37%; contralateral lung V 5Gy < 26%; and maximum doses for spinal cord, esophagus, trachea/bronchus, and heart and great vessels. Populations were grouped by number of fractions, and dosimetric criteria satisfaction rates (CSRs) were reported. Results: Five fraction regimens were the most common lung SBRT fractionation (46%). The median PTV was 27.2 cm 3 (range: 3.8–419.5 cm 3 ). For all plans: mean PTV V 100 was 94.5% (±5.6%, planning CSR: 69.8%), mean PTV V 95 was 98.1% (±4.1%, CSR: 69.5%), mean CI 100% was 1.14 (±0.21, CSR: 79.1%, and 16.5% within minor deviation), and mean CI 50% was 5.63 (±2.8, CSR: 33.0%, and 28.0% within minor deviation). When comparing plans based on location, peripherally located tumors displayed higher PTV V 100 and PTV V 95 CSR (71.5% and 71.9%, respectively) than centrally located tumors (61.2% and 57.1%, respectively). Overall, the planning criteria were met for all the critical structure such as lung, heart

  1. An interactive beam-weight optimization tool for three-dimensional radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Burba, S.; Gardey, K.; Nadobny, J.; Stalling, D.; Seebass, M.; Beier, J.; Wust, P.; Budach, V.; Felix, R.

    1997-01-01

    Purpose: A computer software tool has been developed to aid the treatment planner in selecting beam weights for three-dimensional radiotherapy treatment planning. An approach to plan optimization has been made that is based on the use of an iterative feasibility search algorithm combined with a quadratic convergence method that seeks a set of beam weights which satisfies all the dose constraints set by the planner. Materials and Methods: A FORTRAN module for dose calculation for radiotherapy (a VOXELPLAN modification) has been integrated into an object-oriented Silicon Graphics TM platform in an IRIS Inventor environment on basis of the OpenGL which up to now has been exclusively used for the calculation of E-field distributions in hyperthermia (HyperPlan TM ). After the successful calculation and representation of the dose distribution in the Silicon Graphics TM platform, an algorithm involving the minimization method according to the principle of quadratic convergence was developed for optimizing beam weights of a number of pre-calculated fields. The verification of the algorithms for dose calculation and dose optimization has been realized by use of a standardized interface to the program VIRTUOS as well as by the collapsed cone algorithm implemented in the commercial treatment planning system Helax TMS TM . Results: The search algorithm allows the planner to incorporate relative importance weightings to target volumes and anatomical structures, specifying, for example, that a dose constraint to the spinal cord is much more crucial to the overall evaluation of a treatment plan than a dose constraint to otherwise uninvolved soft tissue. In most cases the applied minimization method according to the model of Davidon-Fletcher-Powell showed ultimate fast convergence for a general function f(x) with continuous second derivatives and fast convergence for a positive definite quadratic function. In other cases, however, the absence of an acceptable solution may indicate

  2. Practical aspects and uncertainty analysis of biological effective dose (BED) regarding its three-dimensional calculation in multiphase radiotherapy treatment plans.

    Science.gov (United States)

    Kauweloa, Kevin I; Gutierrez, Alonso N; Bergamo, Angelo; Stathakis, Sotirios; Papanikolaou, Nikos; Mavroidis, Panayiotis

    2014-07-01

    There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximate BED formulation, relative to the true BED. The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning systems due to the inconsistent accuracy of

  3. Influence of optimizing protocol choice on the integral dose value in prostate radiotherapy planning by dynamic techniques - Pilot study.

    Science.gov (United States)

    Zaleska, Anna; Bogaczyk, Krzysztof; Piotrowski, Tomasz

    2017-01-01

    The purpose of this study was to compare the values of integral dose, calculated for treatment plans of dynamic radiotherapy techniques prepared with two different optimization protocols. Delivering radiation by IMRT, VMAT and also HT techniques has an influence on the low dose deposition of large areas of the patient body. Delivery of low dose can induce injury of healthy cells. In this situation, a good solution would be to reduce the area, which receives a low dose, but with appropriate dose level for the target volume. To calculate integral dose values of plans structures, we used 90 external beam radiotherapy plans prepared for three techniques (intensity modulated radiotherapy, volumetric modulated arc therapy and helical tomotherapy). One technique includes three different geometry combinations. 45 plans were prepared with classic optimization protocol and 45 with rings optimization protocol which should reduce the low doses in the normal tissue. Differences in values of the integral dose depend on the geometry and technique of irradiation, as well as optimization protocol used in preparing treatment plans. The application of the rings optimization caused the value of normal tissue integral dose (NTID) to decrease. It is possible to limit the area of low dose irradiation and reduce NTID in dynamic techniques with the same clinical constraints for OAR and PTV volumes by using an optimization protocol other than the classic one.

  4. Effects of urethrography on prostate position: considerations for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Malone, S.; Crook, J.; Perry, G.; Broeders, M.; Salhani, D.; Gerig, L.; Szanto, J.; Bociek, G.

    1997-01-01

    Purpose/Objective: Prostate carcinoma involves the apex of the gland in 80 % of patients; therefore, accurate identification of the apex is critical for radiotherapy treatment planning. Urethrography is commonly used to identify the prostate apex during simulation. The authors were concerned that urethrography could cause prostate motion and thus may not be the ideal method to define the inferior field border. A study was carried out to examine the effects of urethrography on prostate position. Materials and Methods: In preparation for radiotherapy, 3 gold seeds are placed under ultrasound guidance in the prostate (apex, posterior wall, base). The fiducials are used in treatment planning and allow us to track prostate position during radiotherapy. In addition, the fiducials allowed us to examine the effects of urethrography on prostate position. At simulation, the inferior field border is defined 1.5 cm below the tip of the urethral cone or 2.5 cm below the apical seed. In 20 patients the seed-defined apex at simulation (urethrogram performed) was compared to the seed-defined apex on the day 1 port films (no urethrogram). In a second cohort of 25 patients we prospectively evaluated the effects of urethrography during simulation. Following field definition, simulation films were taken for baseline prostate position. Urethrogram was performed and repeat films were taken. To assess prostate motion the distance of the apical seed to the inferior public symphysis was measured on the paired AP films and the distance of the posterior and base seeds to the anterior pubic symphysis was measured on the paired lateral films. Results: In the 45 patients the mean superior shift of the prostate with urethrogram was 6 mm (range: -4 to 16 mm) and mean anterior shift was 4 mm (range: -7 to 8 mm). Urethrography caused a superior shift of the prostate in 44 patients and in 62%, the displacement was 5 mm or more. The impact of urethrogram-induced prostate motion on dose coverage was

  5. Dosimetric impact of image artifact from a wide-bore CT scanner in radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Vincent; Podgorsak, Matthew B.; Tran, Tuan-Anh; Malhotra, Harish K.; Wang, Iris Z. [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2011-07-15

    Purpose: Traditional computed tomography (CT) units provide a maximum scan field-of-view (sFOV) diameter of 50 cm and a limited bore size, which cannot accommodate a large patient habitus or an extended simulation setup in radiation therapy (RT). Wide-bore CT scanners with increased bore size were developed to address these needs. Some scanners have the capacity to reconstruct the CT images at an extended FOV (eFOV), through data interpolation or extrapolation, using projection data acquired with a conventional sFOV. Objects that extend past the sFOV for eFOV reconstruction may generate image artifacts resulting from truncated projection data; this may distort CT numbers and structure contours in the region beyond the sFOV. The purpose of this study was to evaluate the dosimetric impact of image artifacts from eFOV reconstruction with a wide-bore CT scanner in radiotherapy (RT) treatment planning. Methods: Testing phantoms (i.e., a mini CT phantom with equivalent tissue inserts, a set of CT normal phantoms and anthropomorphic phantoms of the thorax and the pelvis) were used to evaluate eFOV artifacts. Reference baseline images of these phantoms were acquired with the phantom centrally positioned within the sFOV. For comparison, the phantoms were then shifted laterally and scanned partially outside the sFOV, but still within the eFOV. Treatment plans were generated for the thoracic and pelvic anthropomorphic phantoms utilizing the Eclipse treatment planning system (TPS) to study the potential effects of eFOV artifacts on dose calculations. All dose calculations of baseline and test treatment plans were carried out using the same MU. Results: Results show that both body contour and CT numbers are altered by image artifacts in eFOV reconstruction. CT number distortions of up to -356 HU for bone tissue and up to 323 HU for lung tissue were observed in the mini CT phantom. Results from the large body normal phantom, which is close to a clinical patient size, show

  6. Medical images fusion for application in treatment planning systems in radiotherapy

    International Nuclear Information System (INIS)

    Ros, Renato Assenci

    2006-01-01

    Software for medical images fusion was developed for utilization in CAT3D radiotherapy and MNPS radiosurgery treatment planning systems. A mutual information maximization methodology was used to make the image registration of different modalities by measure of the statistical dependence between the voxels pairs. The alignment by references points makes an initial approximation to the non linear optimization process by downhill simplex method for estimation of the joint histogram. The coordinates transformation function use a trilinear interpolation and search for the global maximum value in a 6 dimensional space, with 3 degree of freedom for translation and 3 degree of freedom for rotation, by making use of the rigid body model. This method was evaluated with CT, MR and PET images from Vanderbilt University database to verify its accuracy by comparison of transformation coordinates of each images fusion with gold-standard values. The median of images alignment error values was 1.6 mm for CT-MR fusion and 3.5 mm for PET-MR fusion, with gold-standard accuracy estimated as 0.4 mm for CT-MR fusion and 1.7 mm for PET-MR fusion. The maximum error values were 5.3 mm for CT-MR fusion and 7.4 mm for PET-MR fusion, and 99.1% of alignment errors were images subvoxels values. The mean computing time was 24 s. The software was successfully finished and implemented in 59 radiotherapy routine services, of which 42 are in Brazil and 17 are in Latin America. This method does not have limitation about different resolutions from images, pixels sizes and slice thickness. Besides, the alignment may be accomplished by axial, coronal or sagittal images. (author)

  7. Improving oncoplastic breast tumor bed localization for radiotherapy planning using image registration algorithms

    Science.gov (United States)

    Wodzinski, Marek; Skalski, Andrzej; Ciepiela, Izabela; Kuszewski, Tomasz; Kedzierawski, Piotr; Gajda, Janusz

    2018-02-01

    Knowledge about tumor bed localization and its shape analysis is a crucial factor for preventing irradiation of healthy tissues during supportive radiotherapy and as a result, cancer recurrence. The localization process is especially hard for tumors placed nearby soft tissues, which undergo complex, nonrigid deformations. Among them, breast cancer can be considered as the most representative example. A natural approach to improving tumor bed localization is the use of image registration algorithms. However, this involves two unusual aspects which are not common in typical medical image registration: the real deformation field is discontinuous, and there is no direct correspondence between the cancer and its bed in the source and the target 3D images respectively. The tumor no longer exists during radiotherapy planning. Therefore, a traditional evaluation approach based on known, smooth deformations and target registration error are not directly applicable. In this work, we propose alternative artificial deformations which model the tumor bed creation process. We perform a comprehensive evaluation of the most commonly used deformable registration algorithms: B-Splines free form deformations (B-Splines FFD), different variants of the Demons and TV-L1 optical flow. The evaluation procedure includes quantitative assessment of the dedicated artificial deformations, target registration error calculation, 3D contour propagation and medical experts visual judgment. The results demonstrate that the currently, practically applied image registration (rigid registration and B-Splines FFD) are not able to correctly reconstruct discontinuous deformation fields. We show that the symmetric Demons provide the most accurate soft tissues alignment in terms of the ability to reconstruct the deformation field, target registration error and relative tumor volume change, while B-Splines FFD and TV-L1 optical flow are not an appropriate choice for the breast tumor bed localization problem

  8. Knowledge-light adaptation approaches in case-based reasoning for radiotherapy treatment planning.

    Science.gov (United States)

    Petrovic, Sanja; Khussainova, Gulmira; Jagannathan, Rupa

    2016-03-01

    Radiotherapy treatment planning aims at delivering a sufficient radiation dose to cancerous tumour cells while sparing healthy organs in the tumour-surrounding area. It is a time-consuming trial-and-error process that requires the expertise of a group of medical experts including oncologists and medical physicists and can take from 2 to 3h to a few days. Our objective is to improve the performance of our previously built case-based reasoning (CBR) system for brain tumour radiotherapy treatment planning. In this system, a treatment plan for a new patient is retrieved from a case base containing patient cases treated in the past and their treatment plans. However, this system does not perform any adaptation, which is needed to account for any difference between the new and retrieved cases. Generally, the adaptation phase is considered to be intrinsically knowledge-intensive and domain-dependent. Therefore, an adaptation often requires a large amount of domain-specific knowledge, which can be difficult to acquire and often is not readily available. In this study, we investigate approaches to adaptation that do not require much domain knowledge, referred to as knowledge-light adaptation. We developed two adaptation approaches: adaptation based on machine-learning tools and adaptation-guided retrieval. They were used to adapt the beam number and beam angles suggested in the retrieved case. Two machine-learning tools, neural networks and naive Bayes classifier, were used in the adaptation to learn how the difference in attribute values between the retrieved and new cases affects the output of these two cases. The adaptation-guided retrieval takes into consideration not only the similarity between the new and retrieved cases, but also how to adapt the retrieved case. The research was carried out in collaboration with medical physicists at the Nottingham University Hospitals NHS Trust, City Hospital Campus, UK. All experiments were performed using real-world brain cancer

  9. Radiotherapy, hadron therapy and the treatment planning for heavy ion and proton irradiation

    International Nuclear Information System (INIS)

    Boriano, A.; Bourhaleb, F.; Donetti, M.; Marchetto, F.; Sanz Freire, C.J.; Peroni, C.; Cirio, R.; Derkaoui, J.

    2001-01-01

    The aim of conformal radiation therapy is to deliver the dose as high and as uniform as possible to diseased tissue sparing all the other parts, without causing unwanted and unnecessary side effects for the patient. Difficulties to achieve this goal start with the determination of the three dimensional volumes of interest and end up in realizing a three-dimensional uniform and maximal as possible, the dose distribution. The technique of intensity-modulated radiotherapy (IMRT) as form of conformation in radiation therapy is a real revolution. One of the newest attempts in this field, which reaches to have a great success, is the use of multi-leaf collimators (MLC). It is not the unique new technique. In fact the use of therapeutic ions, especially carbon ions and protons is the technology of the actual future which is really the challenge in conformation of dose to targets, thanks to energy deposition characteristics of hadronic beams. An appropriate treatment planning system is strictly necessary to take full advantage of the novel technique. We have developed, for this purpose, an analytical code in C++ language, running on Unix platform. The package presented, is a special code system dedicated to the planning of radiotherapy with energetic ions. ANCOD is an analytical code using the voxels-scan technique as an active method for irradiating the patients. It is based on an iterative algorithm to determine the best fluencies to realize the optimal dose distribution, delivering a maximum of dose on the target volume and a minimum of dose distribution all around, especially on organs at risk. As input, the code use experimental data of linear energy-loss of a particular set of initial kinetic energies, and as a clinical data a complete set of CT images with contours of volumes of interest. Inverse planning techniques are implemented in order to obtain the initial energies needed for each beam to have a uniform target dose distribution. The package can determine the

  10. Voxel-based dose prediction with multi-patient atlas selection for automated radiotherapy treatment planning

    Science.gov (United States)

    McIntosh, Chris; Purdie, Thomas G.

    2017-01-01

    Automating the radiotherapy treatment planning process is a technically challenging problem. The majority of automated approaches have focused on customizing and inferring dose volume objectives to be used in plan optimization. In this work we outline a multi-patient atlas-based dose prediction approach that learns to predict the dose-per-voxel for a novel patient directly from the computed tomography planning scan without the requirement of specifying any objectives. Our method learns to automatically select the most effective atlases for a novel patient, and then map the dose from those atlases onto the novel patient. We extend our previous work to include a conditional random field for the optimization of a joint distribution prior that matches the complementary goals of an accurately spatially distributed dose distribution while still adhering to the desired dose volume histograms. The resulting distribution can then be used for inverse-planning with a new spatial dose objective, or to create typical dose volume objectives for the canonical optimization pipeline. We investigated six treatment sites (633 patients for training and 113 patients for testing) and evaluated the mean absolute difference in all DVHs for the clinical and predicted dose distribution. The results on average are favorable in comparison to our previous approach (1.91 versus 2.57). Comparing our method with and without atlas-selection further validates that atlas-selection improved dose prediction on average in whole breast (0.64 versus 1.59), prostate (2.13 versus 4.07), and rectum (1.46 versus 3.29) while it is less important in breast cavity (0.79 versus 0.92) and lung (1.33 versus 1.27) for which there is high conformity and minimal dose shaping. In CNS brain, atlas-selection has the potential to be impactful (3.65 versus 5.09), but selecting the ideal atlas is the most challenging.

  11. A class solution for volumetric-modulated arc therapy planning in postprostatectomy radiotherapy

    International Nuclear Information System (INIS)

    Forde, Elizabeth; Bromley, Regina; Kneebone, Andrew; Eade, Thomas

    2014-01-01

    This study is aimed to test a postprostatectomy volumetric-modulated arc therapy (VMAT) planning class solution. The solution applies to both the progressive resolution optimizer algorithm version 2 (PRO 2) and the algorithm version 3 (PRO 3), addressing the effect of an upgraded algorithm. A total of 10 radical postprostatectomy patients received 68 Gy to 95% of the planning target volume (PTV), which was planned using VMAT. Each case followed a set of planning instructions; including contouring, field setup, and predetermined optimization parameters. Each case was run through both algorithms only once, with no user interaction. Results were averaged and compared against Radiation Therapy Oncology Group (RTOG) 0534 end points. In addition, the clinical target volume (CTV) D 100 , PTV D 99 , and PTV mean doses were recorded, along with conformity indices (CIs) (95% and 98%) and the homogeneity index. All cases satisfied PTV D 95 of 68 Gy and a maximum dose < 74.8 Gy. The average result for the PTV D 99 was 64.1 Gy for PRO 2 and 62.1 Gy for PRO 3. The average PTV mean dose for PRO 2 was 71.4 Gy and 71.5 Gy for PRO 3. The CTV D 100 average dose was 67.7 and 68.0 Gy for PRO 2 and PRO 3, respectively. The mean homogeneity index for both algorithms was 0.08. The average 95% CI was 1.17 for PRO 2 and 1.19 for PRO 3. For 98%, the average results were 1.08 and 1.12 for PRO 2 and PRO 3, respectively. All cases for each algorithm met the RTOG organs at risk dose constraints. A successful class solution has been established for prostate bed VMAT radiotherapy regardless of the algorithm used

  12. A class solution for volumetric-modulated arc therapy planning in postprostatectomy radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Bromley, Regina [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales (Australia); Kneebone, Andrew; Eade, Thomas [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia)

    2014-10-01

    This study is aimed to test a postprostatectomy volumetric-modulated arc therapy (VMAT) planning class solution. The solution applies to both the progressive resolution optimizer algorithm version 2 (PRO 2) and the algorithm version 3 (PRO 3), addressing the effect of an upgraded algorithm. A total of 10 radical postprostatectomy patients received 68 Gy to 95% of the planning target volume (PTV), which was planned using VMAT. Each case followed a set of planning instructions; including contouring, field setup, and predetermined optimization parameters. Each case was run through both algorithms only once, with no user interaction. Results were averaged and compared against Radiation Therapy Oncology Group (RTOG) 0534 end points. In addition, the clinical target volume (CTV) D{sub 100}, PTV D{sub 99}, and PTV mean doses were recorded, along with conformity indices (CIs) (95% and 98%) and the homogeneity index. All cases satisfied PTV D{sub 95} of 68 Gy and a maximum dose < 74.8 Gy. The average result for the PTV D{sub 99} was 64.1 Gy for PRO 2 and 62.1 Gy for PRO 3. The average PTV mean dose for PRO 2 was 71.4 Gy and 71.5 Gy for PRO 3. The CTV D{sub 100} average dose was 67.7 and 68.0 Gy for PRO 2 and PRO 3, respectively. The mean homogeneity index for both algorithms was 0.08. The average 95% CI was 1.17 for PRO 2 and 1.19 for PRO 3. For 98%, the average results were 1.08 and 1.12 for PRO 2 and PRO 3, respectively. All cases for each algorithm met the RTOG organs at risk dose constraints. A successful class solution has been established for prostate bed VMAT radiotherapy regardless of the algorithm used.

  13. Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy.

    Science.gov (United States)

    Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

    2016-06-01

    To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1-2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85-6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins. © 2016 The Royal Australian and New Zealand College of Radiologists.

  14. Assessment of function and quality of life in a phase II multi-institutional clinical trial of fractionated simultaneous in-field boost radiotherapy for patients with 1-3 metastases.

    Science.gov (United States)

    Bauman, Glenn; Yartsev, Slav; Roberge, David; MacRae, Robert; Roa, Wilson; Panet-Raymond, Valerie; Masucci, Laura; Yaremko, Brian; D'Souza, David; Palma, David; Sexton, Tracy; Yu, Edward; Pantarotto, Jason R; Ahmad, Belal; Fisher, Barbara; Dar, A Rashid; Lambert, Carole; Pond, Gregory; Stitt, Larry; Tay, Keng Yeow; Rodrigues, George

    2016-07-01

    We examined functional outcomes and quality of life of whole brain radiotherapy (WBRT) with integrated fractionated stereotactic radiotherapy boost (FSRT) for brain metastases treatment. Eighty seven people with 1-3 brain metastases (54/87 lung primary, 42/87 single brain metastases) were enrolled on this Phase II trial of WBRT (30 Gy/10) + simultaneous FSRT, (60 Gy/10). Median overall follow-up and survival was 5.4 months, 6 month actuarial intra-lesional control was 78 %; only 1 patient exhibited grade 4 toxicity (worsened seizures); most treatment related toxicity was grade 1 or 2; 2/87 patients demonstrated asymptomatic radiation necrosis on follow-up imaging. Mean (Min-Max) baseline KPS, Mini Mental Status Exam (MMSE) and FACT-BR quality of life were 83 (70-100), 28 (21-30) and 143 (98-153). Lower baseline MMSE (but not KPS or FACT-Br) was associated with worse survival after adjusting for age, number of metastases, primary and extra-cranial disease status. Crude rates of deterioration (>10 points decrease from baseline for KPS and FACT-Br, MMSE fall to <27) ranged from 26 to 38 % for KPS, 32-59 % for FACT-Br and 0-16 % for MMSE depending on the time-point assessed with higher rates generally noted at earlier time points (≤6 months post-treatment). Using a linear mixed models analysis, significant declines from baseline were noted for KPS and FACT-Br (largest effects at 6 weeks to 3 months) with no significant change in MMSE. The effects on function and quality of life of this integrated treatment of WBRT + simultaneous FSRT were similar to other published series combining WBRT + radiosurgery.

  15. A planning comparison of seven irradiation options allowed in RTOG 1005 for early stage breast cancer

    OpenAIRE

    Chen, Guang-Pei; Liu, Feng; White, Julia; Vicini, Frank A.; Freedman, Gary M.; Arthur, Douglas W.; Li, X. Allen

    2014-01-01

    This study compared the seven treatment plan options in achieving the dose-volume criteria required by the RTOG 1005 protocol. Dosimetry plans were generated for 15 representative early stage breast cancer patients based on the protocol required dose-volume criteria for each of the following seven treatment options: 3D conformal radiotherapy (3DCRT) whole breast irradiation (WBI) plus 3DCRT lumpectomy boost, 3DCRT WBI plus electron boost, 3DCRT WBI plus intensity-modulated radiation therapy (...

  16. Impact of the accuracy of automatic tumour functional volume delineation on radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Le Maitre, Amandine; Hatt, Mathieu; Pradier, Olivier; Cheze-le Rest, Catherine; Visvikis, Dimitris

    2012-01-01

    Over the past few years several automatic and semi-automatic PET segmentation methods for target volume definition in radiotherapy have been proposed. The objective of this study is to compare different methods in terms of dosimetry. For such a comparison, a gold standard is needed. For this purpose, realistic GATE-simulated PET images were used. Three lung cases and three H and N cases were designed with various shapes, contrasts and heterogeneities. Four different segmentation approaches were compared: fixed and adaptive thresholds, a fuzzy C-mean and the fuzzy locally adaptive Bayesian method. For each of these target volumes, an IMRT treatment plan was defined. The different algorithms and resulting plans were compared in terms of segmentation errors and ground-truth volume coverage using different metrics (V 95 , D 95 , homogeneity index and conformity index). The major differences between the threshold-based methods and automatic methods occurred in the most heterogeneous cases. Within the two groups, the major differences occurred for low contrast cases. For homogeneous cases, equivalent ground-truth volume coverage was observed for all methods but for more heterogeneous cases, significantly lower coverage was observed for threshold-based methods. Our study demonstrates that significant dosimetry errors can be avoided by using more advanced image-segmentation methods. (paper)

  17. Modulated electron radiotherapy treatment planning using a photon multileaf collimator for post-mastectomized chest walls

    International Nuclear Information System (INIS)

    Salguero, Francisco Javier; Palma, Bianey; Arrans, Rafael; Rosello, Joan; Leal, Antonio

    2009-01-01

    Background and purpose: To evaluate the feasibility of using a photon MLC (xMLC) for modulated electron radiotherapy treatment (MERT) as an alternative to conventional post-mastectomy chest wall (CW) irradiation. A Monte Carlo (MC) based planning system was developed to overcome the inaccuracy of the 'pencil beam' algorithm. MC techniques are known to accurately calculate the dose distributions of electron beams, allowing the explicit simulation of electron interactions within the MLC. Materials and methods: Four real clinical CW cases were planned using MERT which were compared with the conventional electron treatments based on blocks and by a straightforward approach using the MLC, and not the blocks (as an intermediate step to MERT) to shape the same segments with SSD between 60 and 70 cm depending on PTV size. MC calculations were verified with an array of ionization chambers and radiochromic films in a solid water phantom. Results: Tests based on gamma analysis between MC dose distributions and radiochromic film measurements showed an excellent agreement. Differences in the absolute dose measured with a plane-parallel chamber at a reference point were below 3% for all cases. MERT solution showed a better PTV coverage and a significant reduction of the doses to the organs at risk (OARs). Conclusion: MERT can effectively improve the current electron treatments by obtaining a better PTV coverage and sparing healthy tissues. More directly, block-shaped treatments could be replaced by MLC-shaped non-modulated segments providing similar results.

  18. SU-F-T-358: Is Auto-Planning Useful for Volumetric-Modulated Arc Therapy Planning in Rectal Cancer Radiotherapy?

    Energy Technology Data Exchange (ETDEWEB)

    Li, K; Chang, X; Wang, J; Hu, P; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: To evaluate whether Auto-Planning based volumetric-modulated radiotherapy (auto-VMAT) can reduce manual interaction time during treatment planning and improve plan quality for rectal cancer radiotherapy. Methods: Ten rectal cancer patients (stage II and III) after radical resection using Dixon surgery were enrolled. All patients were treated with VMAT technique. The manual VMAT plans (man-VMAT) were designed in the Pinnacle treatment planning system (Version 9.10) following the standard treatment planning procedure developed in our department. Clinical plans were manually designed by our experienced dosimetrists. Additionally, an auto-VMAT plan was created for each patient using Auto-Planning module. However, manual interaction was still applied to meet the clinical requirements. The treatment planning time and plan quality surrogated by the DVH parameters were compared between manual and automated plans. Results: The total planning time and manual interaction time were 50.38 and 4.47 min for the auto-VMAT and 36.81 and 16.94 min for the man-VMAT (t=60.14,−23.86; p=0.000, 0.000). In terms of plan quality, both plans meet the clinical requirements. The PTV homogeneity index (HI) and conformity index (CI) were 0.054 and 0.822 for the auto-VMAT and 0.059 and 0.815 for the man-VMAT (t=−1.72, 0.36;p=0.119,0.730).Compared to the man-VMAT, the auto-VMAT showed reduction of 11.9% and 0.7% in V40 and V50 of the bladder, respectively.The V30 and D mean were reduced by 14.0% and 5.1Gy in the left femur and 12.2% and 3.8Gy in the right femur. Conclusion: The Auto-Planning based VMAT plans not only shows similar or superior plan quality to the manual ones in the rectal cancer radiotherapy, but also improve the planning efficiency significantly. However, manual interactions are still required to achieve a clinically acceptable plan based on our experiences.

  19. SU-F-T-358: Is Auto-Planning Useful for Volumetric-Modulated Arc Therapy Planning in Rectal Cancer Radiotherapy?

    International Nuclear Information System (INIS)

    Li, K; Chang, X; Wang, J; Hu, P; Hu, W

    2016-01-01

    Purpose: To evaluate whether Auto-Planning based volumetric-modulated radiotherapy (auto-VMAT) can reduce manual interaction time during treatment planning and improve plan quality for rectal cancer radiotherapy. Methods: Ten rectal cancer patients (stage II and III) after radical resection using Dixon surgery were enrolled. All patients were treated with VMAT technique. The manual VMAT plans (man-VMAT) were designed in the Pinnacle treatment planning system (Version 9.10) following the standard treatment planning procedure developed in our department. Clinical plans were manually designed by our experienced dosimetrists. Additionally, an auto-VMAT plan was created for each patient using Auto-Planning module. However, manual interaction was still applied to meet the clinical requirements. The treatment planning time and plan quality surrogated by the DVH parameters were compared between manual and automated plans. Results: The total planning time and manual interaction time were 50.38 and 4.47 min for the auto-VMAT and 36.81 and 16.94 min for the man-VMAT (t=60.14,−23.86; p=0.000, 0.000). In terms of plan quality, both plans meet the clinical requirements. The PTV homogeneity index (HI) and conformity index (CI) were 0.054 and 0.822 for the auto-VMAT and 0.059 and 0.815 for the man-VMAT (t=−1.72, 0.36;p=0.119,0.730).Compared to the man-VMAT, the auto-VMAT showed reduction of 11.9% and 0.7% in V40 and V50 of the bladder, respectively.The V30 and D mean were reduced by 14.0% and 5.1Gy in the left femur and 12.2% and 3.8Gy in the right femur. Conclusion: The Auto-Planning based VMAT plans not only shows similar or superior plan quality to the manual ones in the rectal cancer radiotherapy, but also improve the planning efficiency significantly. However, manual interactions are still required to achieve a clinically acceptable plan based on our experiences.

  20. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Vincent W.C., E-mail: htvinwu@polyu.edu.hk [Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR (Hong Kong); Tse, Teddy K.H.; Ho, Cola L.M.; Yeung, Eric C.Y. [Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR (Hong Kong)

    2013-07-01

    Monte Carlo (MC) simulation is currently the most accurate dose calculation algorithm in radiotherapy planning but requires relatively long processing time. Faster model-based algorithms such as the anisotropic analytical algorithm (AAA) by the Eclipse treatment planning system and multigrid superposition (MGS) by the XiO treatment planning system are 2 commonly used algorithms. This study compared AAA and MGS against MC, as the gold standard, on brain, nasopharynx, lung, and prostate cancer patients. Computed tomography of 6 patients of each cancer type was used. The same hypothetical treatment plan using the same machine and treatment prescription was computed for each case by each planning system using their respective dose calculation algorithm. The doses at reference points including (1) soft tissues only, (2) bones only, (3) air cavities only, (4) soft tissue-bone boundary (Soft/Bone), (5) soft tissue-air boundary (Soft/Air), and (6) bone-air boundary (Bone/Air), were measured and compared using the mean absolute percentage error (MAPE), which was a function of the percentage dose deviations from MC. Besides, the computation time of each treatment plan was recorded and compared. The MAPEs of MGS were significantly lower than AAA in all types of cancers (p<0.001). With regards to body density combinations, the MAPE of AAA ranged from 1.8% (soft tissue) to 4.9% (Bone/Air), whereas that of MGS from 1.6% (air cavities) to 2.9% (Soft/Bone). The MAPEs of MGS (2.6%±2.1) were significantly lower than that of AAA (3.7%±2.5) in all tissue density combinations (p<0.001). The mean computation time of AAA for all treatment plans was significantly lower than that of the MGS (p<0.001). Both AAA and MGS algorithms demonstrated dose deviations of less than 4.0% in most clinical cases and their performance was better in homogeneous tissues than at tissue boundaries. In general, MGS demonstrated relatively smaller dose deviations than AAA but required longer computation time.

  1. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Wu, Vincent W.C.; Tse, Teddy K.H.; Ho, Cola L.M.; Yeung, Eric C.Y.

    2013-01-01

    Monte Carlo (MC) simulation is currently the most accurate dose calculation algorithm in radiotherapy planning but requires relatively long processing time. Faster model-based algorithms such as the anisotropic analytical algorithm (AAA) by the Eclipse treatment planning system and multigrid superposition (MGS) by the XiO treatment planning system are 2 commonly used algorithms. This study compared AAA and MGS against MC, as the gold standard, on brain, nasopharynx, lung, and prostate cancer patients. Computed tomography of 6 patients of each cancer type was used. The same hypothetical treatment plan using the same machine and treatment prescription was computed for each case by each planning system using their respective dose calculation algorithm. The doses at reference points including (1) soft tissues only, (2) bones only, (3) air cavities only, (4) soft tissue-bone boundary (Soft/Bone), (5) soft tissue-air boundary (Soft/Air), and (6) bone-air boundary (Bone/Air), were measured and compared using the mean absolute percentage error (MAPE), which was a function of the percentage dose deviations from MC. Besides, the computation time of each treatment plan was recorded and compared. The MAPEs of MGS were significantly lower than AAA in all types of cancers (p<0.001). With regards to body density combinations, the MAPE of AAA ranged from 1.8% (soft tissue) to 4.9% (Bone/Air), whereas that of MGS from 1.6% (air cavities) to 2.9% (Soft/Bone). The MAPEs of MGS (2.6%±2.1) were significantly lower than that of AAA (3.7%±2.5) in all tissue density combinations (p<0.001). The mean computation time of AAA for all treatment plans was significantly lower than that of the MGS (p<0.001). Both AAA and MGS algorithms demonstrated dose deviations of less than 4.0% in most clinical cases and their performance was better in homogeneous tissues than at tissue boundaries. In general, MGS demonstrated relatively smaller dose deviations than AAA but required longer computation time

  2. Comment on genetic and global algorithms for optimization of three-dimensional conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Vaarkamp, Jaap [Joint Department of Physics, Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom). E-mail: jaap@icr.ac.uk

    2001-06-01

    Full text: I would like to make four comments on three papers by two authors (Wu and Zhu 2000, 2001, Wu et al 2000) on one topic: optimization of 3D conformal radiotherapy treatment planning. In the papers, genetic and global algorithms are proposed for this optimization, and the authors claim to be able to generate better treatment plans than those produced manually and used for patient treatment (Wu and Zhu 2000). However, the data in the papers do not warrant such a conclusion and the work contains such serious methodological flaws that only the opposite can have been true. First, in the papers a few treatment plans for patients with different brain tumours are discussed. Dose volume histograms (DVHs) are presented for the target, sometimes the planning target volume, sometimes the clinical target volume, and the organs at risk (OARs): left and right eye, and thyroid or spinal cord. However, other OARs limit dose more in clinical treatment planning, and it is those OARs to which the planner must direct all effort when optimizing the treatment plan. One such important OAR when treating children is the temporal lobes because the dose to the temporal lobes has been associated with a reduction in IQ points (Fuss et al 2000). Also particularly important when treating children are the hypothalamus and pituitary, because they influence growth and the further hormonal development (Schmiegelow et al 1999, 2000). Furthermore, rather than the eyes themselves, the optic chiasm usually gets more serious attention (Fuss et al 1999) and is considered so important that it is often blocked from the treatment fields during the final fractions, thus compromising dose homogeneity in the target. Finally, irradiating the auditory apparatus can lead to a loss of hearing (Lin et al 2000), and, in particular when one side receives a high dose, every effort is made to at least spare the other side. Hence, it is not surprising to find a treatment plan that is superior in some of the

  3. Intensity-modulated arc therapy with simultaneous integrated boost in the treatment of primary irresectable cervical cancer. Treatment planning, quality control, and clinical implementation

    International Nuclear Information System (INIS)

    Vandecasteele, Katrien; De Neve, Wilfried; De Gersem, Werner; Paelinck, Leen; Fonteyne, Valerie; De Wagter, Carlos; De Meerleer, Gert; Delrue, Louke; Villeirs, Geert; Makar, Amin

    2009-01-01

    Purpose: to report on the planning procedure, quality control, and clinical implementation of intensity-modulated arc therapy (IMAT) delivering a simultaneous integrated boost (SIB) in patients with primary irresectable cervix carcinoma. Patients and methods: six patients underwent PET-CT (positron emission tomography-computed tomography) and MRI (magnetic resonance imaging) before treatment planning. Prescription (25 fractions) was (1) a median dose (D 50 ) of 62, 58 and 56 Gy to the primary tumor (GTVcervix), primary clinical target volume (CTVcervix) and its planning target volume (PTVcervix), respectively; (2) a D 50 of 60 Gy to the PET-positive lymph nodes (GTVnodes); (3) a minimal dose (D 98 ) of 45 Gy to the planning target volume of the elective lymph nodes (PTVnodes). IMAT plans were generated using an anatomy-based exclusion tool with the aid of weight and leaf position optimization. The dosimetric delivery of IMAT was validated preclinically using radiochromic film dosimetry. Results: five to nine arcs were needed to create valid IMAT plans. Dose constraints on D 50 were not met in two patients (both GTVcervix: 1 Gy and 3 Gy less). D 98 for PTVnodes was not met in three patients (1 Gy each). Film dosimetry showed excellent gamma evaluation. There were no treatment interruptions. Conclusion: IMAT allows delivering an SIB to the macroscopic tumor without compromising the dose to the elective lymph nodes or the organs at risk. The clinical implementation is feasible. (orig.)

  4. Intensity-modulated arc therapy with simultaneous integrated boost in the treatment of primary irresectable cervical cancer. Treatment planning, quality control, and clinical implementation

    Energy Technology Data Exchange (ETDEWEB)

    Vandecasteele, Katrien; De Neve, Wilfried; De Gersem, Werner; Paelinck, Leen; Fonteyne, Valerie; De Wagter, Carlos; De Meerleer, Gert [Dept. of Radiotherapy, Ghent Univ. Hospital (Belgium); Delrue, Louke; Villeirs, Geert [Dept. of Radiology, Ghent Univ. Hospital (Belgium); Makar, Amin [Dept. of Gynecology, Ghent Univ. Hospital (Belgium)

    2009-12-15

    Purpose: to report on the planning procedure, quality control, and clinical implementation of intensity-modulated arc therapy (IMAT) delivering a simultaneous integrated boost (SIB) in patients with primary irresectable cervix carcinoma. Patients and methods: six patients underwent PET-CT (positron emission tomography-computed tomography) and MRI (magnetic resonance imaging) before treatment planning. Prescription (25 fractions) was (1) a median dose (D{sub 50}) of 62, 58 and 56 Gy to the primary tumor (GTVcervix), primary clinical target volume (CTVcervix) and its planning target volume (PTVcervix), respectively; (2) a D{sub 50} of 60 Gy to the PET-positive lymph nodes (GTVnodes); (3) a minimal dose (D{sub 98}) of 45 Gy to the planning target volume of the elective lymph nodes (PTVnodes). IMAT plans were generated using an anatomy-based exclusion tool with the aid of weight and leaf position optimization. The dosimetric delivery of IMAT was validated preclinically using radiochromic film dosimetry. Results: five to nine arcs were needed to create valid IMAT plans. Dose constraints on D{sub 50} were not met in two patients (both GTVcervix: 1 Gy and 3 Gy less). D{sub 98} for PTVnodes was not met in three patients (1 Gy each). Film dosimetry showed excellent gamma evaluation. There were no treatment interruptions. Conclusion: IMAT allows delivering an SIB to the macroscopic tumor without compromising the dose to the elective lymph nodes or the organs at risk. The clinical implementation is feasible. (orig.)

  5. Photon energy-modulated radiotherapy: Monte Carlo simulation and treatment planning study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Min; Kim, Jung-in; Heon Choi, Chang; Chie, Eui Kyu; Kim, Il Han; Ye, Sung-Joon [Interdiciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, 110-744, Korea and Department of Radiation Oncology, Seoul National University Hospital, Seoul, 110-744 (Korea, Republic of); Interdiciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, 110-744 (Korea, Republic of); Department of Radiation Oncology, Seoul National University Hospital, Seoul, 110-744 (Korea, Republic of); Interdiciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, 110-744 (Korea, Republic of) and Department of Radiation Oncology, Seoul National University Hospital, Seoul, 110-744 (Korea, Republic of); Interdiciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, 110-744 (Korea, Republic of); Department of Radiation Oncology, Seoul National University Hospital, Seoul, 110-744 (Korea, Republic of) and Department of Intelligent Convergence Systems, Seoul National University, Seoul, 151-742 (Korea, Republic of)

    2012-03-15

    Purpose: To demonstrate the feasibility of photon energy-modulated radiotherapy during beam-on time. Methods: A cylindrical device made of aluminum was conceptually proposed as an energy modulator. The frame of the device was connected with 20 tubes through which mercury could be injected or drained to adjust the thickness of mercury along the beam axis. In Monte Carlo (MC) simulations, a flattening filter of 6 or 10 MV linac was replaced with the device. The thickness of mercury inside the device varied from 0 to 40 mm at the field sizes of 5 x 5 cm{sup 2} (FS5), 10 x 10 cm{sup 2} (FS10), and 20 x 20 cm{sup 2} (FS20). At least 5 billion histories were followed for each simulation to create phase space files at 100 cm source to surface distance (SSD). In-water beam data were acquired by additional MC simulations using the above phase space files. A treatment planning system (TPS) was commissioned to generate a virtual machine using the MC-generated beam data. Intensity modulated radiation therapy (IMRT) plans for six clinical cases were generated using conventional 6 MV, 6 MV flattening filter free, and energy-modulated photon beams of the virtual machine. Results: As increasing the thickness of mercury, Percentage depth doses (PDD) of modulated 6 and 10 MV after the depth of dose maximum were continuously increased. The amount of PDD increase at the depth of 10 and 20 cm for modulated 6 MV was 4.8% and 5.2% at FS5, 3.9% and 5.0% at FS10 and 3.2%-4.9% at FS20 as increasing the thickness of mercury from 0 to 20 mm. The same for modulated 10 MV was 4.5% and 5.0% at FS5, 3.8% and 4.7% at FS10 and 4.1% and 4.8% at FS20 as increasing the thickness of mercury from 0 to 25 mm. The outputs of modulated 6 MV with 20 mm mercury and of modulated 10 MV with 25 mm mercury were reduced into 30%, and 56% of conventional linac, respectively. The energy-modulated IMRT plans had less integral doses than 6 MV IMRT or 6 MV flattening filter free plans for tumors located in the

  6. Development of the DVH management software for the biologically-guided evaluation of radiotherapy plan

    International Nuclear Information System (INIS)

    Kim, Bo Kyung; Park, Hee Chul; Oh, Dong Ryul; Shin, Eun Hyuk; Ahn, Yong Chan; Kim, Jin Sung; Han, Young Yih

    2012-01-01

    To develop the dose volume histogram (DVH) management software which guides the evaluation of radiotherapy (RT) plan of a new case according to the biological consequences of the DVHs from the previously treated patients. We determined the radiation pneumonitis (RP) as an biological response parameter in order to develop DVH management software. We retrospectively reviewed the medical records of lung cancer patients treated with curative 3-dimensional conformal radiation therapy (3D-CRT). The biological event was defined as RP of the Radiation Therapy Oncology Group (RTOG) grade III or more. The DVH management software consisted of three parts (pre-existing DVH database, graphical tool, and Pinnacle3 script). The pre-existing DVH data were retrieved from 128 patients. RP events were tagged to the specific DVH data through retrospective review of patients' medical records. The graphical tool was developed to present the complication histogram derived from the preexisting database (DVH and RP) and was implemented into the radiation treatment planning (RTP) system, Pinnacle3 v8.0 (Phillips Healthcare). The software was designed for the pre-existing database to be updated easily by tagging the specific DVH data with the new incidence of RP events at the time of patients' follow-up. We developed the DVH management software as an effective tool to incorporate the phenomenological consequences derived from the pre-existing database in the evaluation of a new RT plan. It can be used not only for lung cancer patients but also for the other disease site with different toxicity parameters.

  7. 3D Ultrasound Can Contribute to Planning CT to Define the Target for Partial Breast Radiotherapy

    International Nuclear Information System (INIS)

    Berrang, Tanya S.; Truong, Pauline T.; Popescu, Carmen; Drever, Laura; Kader, Hosam A.; Hilts, Michelle L.; Mitchell, Tracy; Soh, S.Y.; Sands, Letricia; Silver, Stuart; Olivotto, Ivo A.

    2009-01-01

    Purpose: The role of three-dimensional breast ultrasound (3D US) in planning partial breast radiotherapy (PBRT) is unknown. This study evaluated the accuracy of coregistration of 3D US to planning computerized tomography (CT) images, the seroma contouring consistency of radiation oncologists using the two imaging modalities and the clinical situations in which US was associated with improved contouring consistency compared to CT. Materials and Methods: Twenty consecutive women with early-stage breast cancer were enrolled prospectively after breast-conserving surgery. Subjects underwent 3D US at CT simulation for adjuvant RT. Three radiation oncologists independently contoured the seroma on separate CT and 3D US image sets. Seroma clarity, seroma volumes, and interobserver contouring consistency were compared between the imaging modalities. Associations between clinical characteristics and seroma clarity were examined using Pearson correlation statistics. Results: 3D US and CT coregistration was accurate to within 2 mm or less in 19/20 (95%) cases. CT seroma clarity was reduced with dense breast parenchyma (p = 0.035), small seroma volume (p < 0.001), and small volume of excised breast tissue (p = 0.01). US seroma clarity was not affected by these factors (p = NS). US was associated with improved interobserver consistency compared with CT in 8/20 (40%) cases. Of these 8 cases, 7 had low CT seroma clarity scores and 4 had heterogeneously to extremely dense breast parenchyma. Conclusion: 3D US can be a useful adjunct to CT in planning PBRT. Radiation oncologists were able to use US images to contour the seroma target, with improved interobserver consistency compared with CT in cases with dense breast parenchyma and poor CT seroma clarity

  8. Magnetic resonance imaging for prostate bed radiotherapy planning: An inter- and intra-observer variability study

    International Nuclear Information System (INIS)

    Barkati, Maroie; Simard, Dany; Taussky, Daniel; Delouya, Guiula

    2016-01-01

    We assessed the inter- and intra-observer variability in contouring the prostate bed for radiation therapy planning using MRI compared with computed tomography (CT). We selected 15 patients with prior radical prostatectomy. All had CT and MRI simulation for planning purposes. Image fusions were done between CT and MRI. Three radiation oncologists with several years of experience in treating prostate cancer contoured the prostate bed first on CT and then on MRI. Before contouring, each radiation oncologist had to review the Radiation Therapy Oncology Group guidelines for postoperative external beam radiotherapy. The agreement between volumes was calculated using the Dice similarity coefficient (DSC). Analysis was done using the Matlab software. The DSC was compared using non-parametric statistical tests. Contouring on CT alone showed a statistically significant (P = 0.001) higher similarity between observers with a mean DSC of 0.76 (standard deviation ± 0.05) compared with contouring on MRI with a mean of 0.66 (standard deviation ± 0.05). Mean intra-observer variability between CT and MRI was 0.68, 0.75 and 0.78 for the three observers. The clinical target volume was 19 - 74% larger on CT than on MRI. The intra-observer difference in clinical target volume between CT and MRI was statistically significant in two observers and non-significant in the third one (P = 0.09). We found less inter-observer variability when contouring on CT than on MRI. Radiation Therapy Oncology Group contouring guidelines are based on anatomical landmarks readily visible on CT. These landmarks are more inter-observer dependent on MRI. Therefore, present contouring guidelines might not be applicable to MRI planning.

  9. 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.

  10. 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

  11. Radiotherapy Planning Using an Improved Search Strategy in Particle Swarm Optimization.

    Science.gov (United States)

    Modiri, Arezoo; Gu, Xuejun; Hagan, Aaron M; Sawant, Amit

    2017-05-01

    Evolutionary stochastic global optimization algorithms are widely used in large-scale, nonconvex problems. However, enhancing the search efficiency and repeatability of these techniques often requires well-customized approaches. This study investigates one such approach. We use particle swarm optimization (PSO) algorithm to solve a 4D radiation therapy (RT) inverse planning problem, where the key idea is to use respiratory motion as an additional degree of freedom in lung cancer RT. The primary goal is to administer a lethal dose to the tumor target while sparing surrounding healthy tissue. Our optimization iteratively adjusts radiation fluence-weights for all beam apertures across all respiratory phases. We implement three PSO-based approaches: conventionally used unconstrained, hard-constrained, and our proposed virtual search. As proof of concept, five lung cancer patient cases are optimized over ten runs using each PSO approach. For comparison, a dynamically penalized likelihood (DPL) algorithm-a popular RT optimization technique is also implemented and used. The proposed technique significantly improves the robustness to random initialization while requiring fewer iteration cycles to converge across all cases. DPL manages to find the global optimum in 2 out of 5 RT cases over significantly more iterations. The proposed virtual search approach boosts the swarm search efficiency, and consequently, improves the optimization convergence rate and robustness for PSO. RT planning is a large-scale, nonconvex optimization problem, where finding optimal solutions in a clinically practical time is critical. Our proposed approach can potentially improve the optimization efficiency in similar time-sensitive problems.

  12. Value of magnetic resonance imaging in the radiotherapy planning of tumours of the uterine cervix: preliminary results

    International Nuclear Information System (INIS)

    Justino, Pitagoras Baskara; Carvalho, Heloisa de Andrade; Baroni, Ronaldo Hueb; Blasbalg, Roberto; Leite, Claudia da Costa

    2005-01-01

    Objective: To assess the rate of geographic miss on conventional radiotherapy planning of patients with cervical cancer, using magnetic resonance imaging. Materials and methods: Thirty-two patients with squamous cell carcinoma of the uterine cervix were studied. Magnetic resonance imaging of the pelvis was performed after clinical staging. Magnetic resonance imaging findings were compared with the classic fields described for the 'box' technique. Target volume within less than 1 cm margins of the fields' limits was considered as geographic miss. Results: Classical radiation field limits were inadequate in 24 cases (75%), all in the anterior (46%) or posterior (40%) border of the lateral fields. Conclusion: Magnetic resonance detected a high probability of geographic miss on conventional radiotherapy planning in this population, both in initial and advanced stages of the disease. (author)

  13. Training, abilities, role and responsibilities of the technician in treatment planning or 'dosimetrist' in radiotherapy

    International Nuclear Information System (INIS)

    Buchheit, Isabelle; Angles, Damien; Marchesi, Vincent; Fau, Pierre; Aubignac, Leone; Palisson, Jeremy; Lacornerie, Thomas; Baron, Pierre-Louis; Popoff, Romain; Llagostera, Camille; Buffard, Edwige; Sarrazin, Thierry; Le Du, Dominique; Estivalet, Andre; Tchong, Bruno; Marcie, Serge; Guerin, Lucie; Parent, Laure

    2013-09-01

    As the creation of treatment plans in radiotherapy (commonly named dosimetry) has become a crucial task in the treatment process, and has been historically performed by the medical physician, it may be delegated to other professionals and there is therefore a need of creation of a profession: the technician in treatment planning or dosimetrist. In order to better define this profession, its role and its education and training requirements, this document describes its role, its required knowledge, abilities and capacities (general knowledge, knowledge in anatomy, oncology and imagery, in radiation production, in ballistic and preparation, in radiotherapy, in breath-based feedback, in body irradiation, in radiation protection, in delimitation of organs at risk, and in administrative issues). The different training levels are indicated: initial training, continuous training, and validation of prior experience. The legal framework and organisational issues are addressed in terms of delegation and responsibility

  14. Planning benchmark study for SBRT of early stage NSCLC. Results of the DEGRO Working Group Stereotactic Radiotherapy

    International Nuclear Information System (INIS)

    Moustakis, Christos; Blanck, Oliver; Ebrahimi Tazehmahalleh, Fatemeh; Chan, Mark ka heng; Ernst, Iris; Haverkamp, Uwe; Eich, Hans Theodor; Krieger, Thomas; Duma, Marciana-Nona; Oechsner, Markus; Ganswindt, Ute; Heinz, Christian; Alheit, Horst; Blank, Hilbert; Nestle, Ursula; Wiehle, Rolf; Kornhuber, Christine; Ostheimer, Christian; Petersen, Cordula; Pollul, Gerhard; Baus, Wolfgang; Altenstein, Georg; Beckers, Eric; Jurianz, Katrin; Sterzing, Florian; Kretschmer, Matthias; Seegenschmiedt, Heinrich; Maass, Torsten; Droege, Stefan; Wolf, Ulrich; Schoeffler, Juergen; Guckenberger, Matthias

    2017-01-01

    The aim was to evaluate stereotactic body radiation therapy (SBRT) treatment planning variability for early stage nonsmall cell lung cancer (NSCLC) with respect to the published guidelines of the Stereotactic Radiotherapy Working Group of the German Society for Radiation Oncology (DEGRO). Planning computed tomography (CT) scan and the structure sets (planning target volume, PTV; organs at risk, OARs) of 3 patients with early stage NSCLC were sent to 22 radiotherapy departments with SBRT experience: each department was asked to prepare a treatment plan according to the DEGRO guidelines. The prescription dose was 3 fractions of 15 Gy to the 65% isodose. In all, 87 plans were generated: 36 used intensity-modulated arc therapy (IMAT), 21 used three-dimensional conformal radiation therapy (3DCRT), 6 used static field intensity-modulated radiation therapy (SF-IMRT), 9 used helical radiotherapy and 15 used robotic radiosurgery. PTV dose coverage and simultaneously kept OARs doses were within the clinical limits published in the DEGRO guidelines. However, mean PTV dose (mean 58.0 Gy, range 52.8-66.4 Gy) and dose conformity indices (mean 0.75, range 0.60-1.00) varied between institutions and techniques (p ≤ 0.02). OARs doses varied substantially between institutions, but appeared to be technique independent (p = 0.21). All studied treatment techniques are well suited for SBRT of early stage NSCLC according to the DEGRO guidelines. Homogenization of SBRT practice in Germany is possible through the guidelines; however, detailed treatment plan characteristics varied between techniques and institutions and further homogenization is warranted in future studies and recommendations. Optimized treatment planning should always follow the ALARA (as low as reasonably achievable) principle. (orig.) [de

  15. 4D motion models over the respiratory cycle for use in lung cancer radiotherapy planning

    Science.gov (United States)

    McClelland, J. R.; Chandler, A. G.; Blackall, J. M.; Ahmad, S.; Landau, D. B.; Hawkes, D. J.

    2005-04-01

    Respiratory motion causes problems of tumour localisation in radiotherapy treatment planning for lung cancer patients. We have developed a novel method of building patient specific motion models, which model the movement and non-rigid deformation of a lung tumour and surrounding lung tissue over the respiratory cycle. Free-breathing (FB) CT scans are acquired in cine mode, using 3 couch positions to acquire contiguous 'slabs' of 16 slices covering the region of interest. For each slab, 20 FB volumes are acquired over approx 20s. A reference volume acquired at Breath Hold (BH) and covering the whole lung, is non-rigidly registered to each of the FB volumes. The FB volumes are assigned a position in the respiratory cycle (PRC) calculated from the displacement of the chest wall. A motion model is then constructed for each slab, by fitting functions that temporally interpolate the registration results over the respiratory cycle. This can produce a prediction of the lung and tumour within the slab at any arbitrary PRC. The predictions for each of the slabs are then combined to produce a volume covering the whole region of interest. Results indicate that the motion modelling method shows considerable promise, offering significant improvement over current clinical practice, and potential advantages over alternative 4D CT imaging techniques. Using this framework, we examined and evaluated several different functions for performing the temporal interpolation. We believe the results of these comparisons will aid future model building for this and other applications.

  16. Verification of absorbed dose calculation with XIO Radiotherapy Treatment Planning System

    International Nuclear Information System (INIS)

    Bokulic, T.; Budanec, M.; Frobe, A.; Gregov, M.; Kusic, Z.; Mlinaric, M.; Mrcela, I.

    2013-01-01

    Modern radiotherapy relies on computerized treatment planning systems (TPS) for absorbed dose calculation. Most TPS require a detailed model of a given machine and therapy beams. International Atomic Energy Agency (IAEA) recommends acceptance testing for the TPS (IAEA-TECDOC-1540). In this study we present customization of those tests for measurements with the purpose of verification of beam models intended for clinical use in our department. Elekta Synergy S linear accelerator installation and data acquisition for Elekta CMS XiO 4.62 TPS was finished in 2011. After the completion of beam modelling in TPS, tests were conducted in accordance with the IAEA protocol for TPS dose calculation verification. The deviations between the measured and calculated dose were recorded for 854 points and 11 groups of tests in a homogenous phantom. Most of the deviations were within tolerance. Similar to previously published results, results for irregular L shaped field and asymmetric wedged fields were out of tolerance for certain groups of points.(author)

  17. A multi-institutional study to assess adherence to lung stereotactic body radiotherapy planning goals

    Energy Technology Data Exchange (ETDEWEB)

    Woerner, Andrew; Roeske, John C.; Harkenrider, Matthew M.; Campana, Maria; Surucu, Murat, E-mail: msurucu@lumc.edu [Loyola University Medical Center, Maywood, Illinois 60153 (United States); Fan, John [Edward Cancer Center, Naperville, Illinois 60540 (United States); Aydogan, Bulent; Koshy, Matthew [Department of Radiation Oncology, University of Illinois at Chicago, Chicago, Illinois 60612 (United States); Laureckas, Robert; Vali, Faisal [Advocate Christ Medical Center, Oak Lawn, Illinois 60453 (United States)

    2015-08-15

    Purpose: A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. Methods: A total of 300 patients receiving lung SBRT treatments in four different institutions were retrospectively reviewed. The treatments were delivered using Linac based SBRT (160 patients) or image guided robotic radiosurgery (140). Most tumors were located peripherally (250/300). Median fractional doses and ranges were 18 Gy (8–20 Gy), 12 Gy (6–15 Gy), and 10 Gy (5–12 Gy) for three, four, and five fraction treatments, respectively. The following planning criteria derived from RTOG trials and the literature were used to evaluate the treatment plans: planning target volumes, PTV{sub V} {sub 100} ≥ 95% and PTV{sub V} {sub 95} ≥ 99%; conformality indices, CI{sub 100%} < 1.2 and CI{sub 50%} range of 2.9–5.9 dependent on PTV; total lung-ITV: V{sub 20Gy} < 10%, V{sub 12.5Gy} < 15%, and V{sub 5Gy} < 37%; contralateral lung V{sub 5Gy} < 26%; and maximum doses for spinal cord, esophagus, trachea/bronchus, and heart and great vessels. Populations were grouped by number of fractions, and dosimetric criteria satisfaction rates (CSRs) were reported. Results: Five fraction regimens were the most common lung SBRT fractionation (46%). The median PTV was 27.2 cm{sup 3} (range: 3.8–419.5 cm{sup 3}). For all plans: mean PTV{sub V} {sub 100} was 94.5% (±5.6%, planning CSR: 69.8%), mean PTV{sub V} {sub 95} was 98.1% (±4.1%, CSR: 69.5%), mean CI{sub 100%} was 1.14 (±0.21, CSR: 79.1%, and 16.5% within minor deviation), and mean CI{sub 50%} was 5.63 (±2.8, CSR: 33.0%, and 28.0% within minor deviation). When comparing plans based on location, peripherally located tumors displayed higher PTV{sub V} {sub 100} and PTV{sub V} {sub 95} CSR (71.5% and 71.9%, respectively) than centrally located tumors (61

  18. SU-E-J-137: Incorporating Tumor Regression Into Robust Plan Optimization for Head and Neck Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, P; Hu, J; Tyagi, N; Mageras, G; Lee, N; Hunt, M [Memorial Sloan-Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: To develop a robust planning paradigm which incorporates a tumor regression model into the optimization process to ensure tumor coverage in head and neck radiotherapy. Methods: Simulation and weekly MR images were acquired for a group of head and neck patients to characterize tumor regression during radiotherapy. For each patient, the tumor and parotid glands were segmented on the MR images and the weekly changes were formulated with an affine transformation, where morphological shrinkage and positional changes are modeled by a scaling factor, and centroid shifts, respectively. The tumor and parotid contours were also transferred to the planning CT via rigid registration. To perform the robust planning, weekly predicted PTV and parotid structures were created by transforming the corresponding simulation structures according to the weekly affine transformation matrix averaged over patients other than him/herself. Next, robust PTV and parotid structures were generated as the union of the simulation and weekly prediction contours. In the subsequent robust optimization process, attainment of the clinical dose objectives was required for the robust PTV and parotids, as well as other organs at risk (OAR). The resulting robust plans were evaluated by looking at the weekly and total accumulated dose to the actual weekly PTV and parotid structures. The robust plan was compared with the original plan based on the planning CT to determine its potential clinical benefit. Results: For four patients, the average weekly change to tumor volume and position was −4% and 1.2 mm laterally-posteriorly. Due to these temporal changes, the robust plans resulted in an accumulated PTV D95 that was, on average, 2.7 Gy higher than the plan created from the planning CT. OAR doses were similar. Conclusion: Integration of a tumor regression model into target delineation and plan robust optimization is feasible and may yield improved tumor coverage. Part of this research is supported

  19. SU-E-J-137: Incorporating Tumor Regression Into Robust Plan Optimization for Head and Neck Radiotherapy

    International Nuclear Information System (INIS)

    Zhang, P; Hu, J; Tyagi, N; Mageras, G; Lee, N; Hunt, M

    2014-01-01

    Purpose: To develop a robust planning paradigm which incorporates a tumor regression model into the optimization process to ensure tumor coverage in head and neck radiotherapy. Methods: Simulation and weekly MR images were acquired for a group of head and neck patients to characterize tumor regression during radiotherapy. For each patient, the tumor and parotid glands were segmented on the MR images and the weekly changes were formulated with an affine transformation, where morphological shrinkage and positional changes are modeled by a scaling factor, and centroid shifts, respectively. The tumor and parotid contours were also transferred to the planning CT via rigid registration. To perform the robust planning, weekly predicted PTV and parotid structures were created by transforming the corresponding simulation structures according to the weekly affine transformation matrix averaged over patients other than him/herself. Next, robust PTV and parotid structures were generated as the union of the simulation and weekly prediction contours. In the subsequent robust optimization process, attainment of the clinical dose objectives was required for the robust PTV and parotids, as well as other organs at risk (OAR). The resulting robust plans were evaluated by looking at the weekly and total accumulated dose to the actual weekly PTV and parotid structures. The robust plan was compared with the original plan based on the planning CT to determine its potential clinical benefit. Results: For four patients, the average weekly change to tumor volume and position was −4% and 1.2 mm laterally-posteriorly. Due to these temporal changes, the robust plans resulted in an accumulated PTV D95 that was, on average, 2.7 Gy higher than the plan created from the planning CT. OAR doses were similar. Conclusion: Integration of a tumor regression model into target delineation and plan robust optimization is feasible and may yield improved tumor coverage. Part of this research is supported

  20. Phase I/II study of preoperative chemo-radiotherapy (CT-RT) using twice daily radiation as concomitant boost during two cycles of taxol (T), cisplatin (C), 5-FU (F) in esophageal cancer: normal tissue tolerance and early results

    International Nuclear Information System (INIS)

    Choi, Noah; Lynch, Thomas; Mathisen, Douglas; Wain, John; Wright, Cameron; Carey, Robert; Grossbard, Michael; Grillo, Hermes

    1997-01-01

    Purpose/Objective: Even though preoperative CT has failed to show survival benefit over surgery alone, preoperative CT-RT may provide such survival advantage. The goal of this study was to evaluate an intensified radiotherapy (RT) schedule in preoperative concurrent CT-RT for toxicities, resection rate, tumor downstaging, pathologic complete remission (CR) and treatment outcome. Materials and Methods: Eligibility included biopsy proven squamous or adenocarcinoma, T2-4N0-1M0 lesions, performance status ≤ 2 of ECOG scale, creatinine ≤ 2.0 mg/dl, WBC ≥ 2,500/μl, and platelets ≥ 75,000//μl. CT consisted of cisplatin (P) 20 mg/m 2 /day (d) x 5 d, 5-FU (F) 800 mg/m 2 /d continuous infusion x 5 d and Taxol (T) 75-125 mg/m 2 (3 hour infusion) on d1 of each cycle. RT delivered 58.5 Gy/34 fractions (F) /5 weeks (wks) to the gross tumor volume by a combination of 45 Gy/25 F/5 wks to a large target volume (6 cm proximal and distal, and 3 cm radial margins beyond the gross tumor) and a boost dose of 13.5 Gy/9 F (1.5 Gy/F x 5 d with the first cycle [wk 1] and 1.5 Gy/F x 4 d with the second cycle [wk 5] of CT) with an interval of ≥ 5 hours between RT to the gross tumor (am) and large target volume (pm) as a means of concomitant boost. Staging work up included barium swallow, chest and head computed tomography, bone scan, esophagoscopy, and endoscopic ultrasound study (EUS). Results: Between April 1995 and February 1997, 38 patients (pts) with locoregional esophageal cancer have been entered into this study. Patient characteristics were as follows: Age 33-84 (median 63), male: female 30 : 8, adenocarcinoma: squamous cell carcinoma 31 : 7. Tumor stages by EUS included T2N0 11 (29%), T2N1 3 (8%), T3N0 14 (37%), T3N1 8 (21%) and T4N0 2 (5%). Taxol dose was escalated from 75 mg/m 2 (7 pts) to 125 mg/m 2 (5 pts) at which dose limiting toxicities were observed in (3(5)) pts (myocardial infarction, pneumonia, grade 4 neutropenia). The remaining 26 pts have been treated with T

  1. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

    International Nuclear Information System (INIS)

    Alves, G.G.; Kinoshita, A.; Oliveira, H.F. de; Guimarães, F.S.; Amaral, L.L.; Baffa, O.

    2015-01-01

    Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses

  2. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Alves, G.G. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Kinoshita, A. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Universidade Sagrado Coração, Bauru, SP (Brazil); Oliveira, H.F. de; Guimarães, F.S.; Amaral, L.L. [Serviço de Radioterapia, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Baffa, O. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2015-05-26

    Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.

  3. Operations research for resource planning and -use in radiotherapy: a literature review.

    Science.gov (United States)

    Vieira, Bruno; Hans, Erwin W; van Vliet-Vroegindeweij, Corine; van de Kamer, Jeroen; van Harten, Wim

    2016-11-25

    The delivery of radiotherapy (RT) involves the use of rather expensive resources and multi-disciplinary staff. As the number of cancer patients receiving RT increases, timely delivery becomes increasingly difficult due to the complexities related to, among others, variable patient inflow, complex patient routing, and the joint planning of multiple resources. Operations research (OR) methods have been successfully applied to solve many logistics problems through the development of advanced analytical models for improved decision making. This paper presents the state of the art in the application of OR methods for logistics optimization in RT, at various managerial levels. A literature search was performed in six databases covering several disciplines, from the medical to the technical field. Papers included in the review were published in peer-reviewed journals from 2000 to 2015. Data extraction includes the subject of research, the OR methods used in the study, the extent of implementation according to a six-stage model and the (potential) impact of the results in practice. From the 33 papers included in the review, 18 addressed problems related to patient scheduling (of which 12 focus on scheduling patients on linear accelerators), 8 focus on strategic decision making, 5 on resource capacity planning, and 2 on patient prioritization. Although calculating promising results, none of the papers reported a full implementation of the model with at least a thorough pre-post performance evaluation, indicating that, apart from possible reporting bias, implementation rates of OR models in RT are probably low. The literature on OR applications in RT covers a wide range of approaches from strategic capacity management to operational scheduling levels, and shows that considerable benefits in terms of both waiting times and resource utilization are likely to be achieved. Various fields can be further developed, for instance optimizing the coordination between the available

  4. Classification of fibroglandular tissue distribution in the breast based on radiotherapy planning CT

    International Nuclear Information System (INIS)

    Juneja, Prabhjot; Evans, Philip; Windridge, David; Harris, Emma

    2016-01-01

    Accurate segmentation of breast tissues is required for a number of applications such as model based deformable registration in breast radiotherapy. The accuracy of breast tissue segmentation is affected by the spatial distribution (or pattern) of fibroglandular tissue (FT). The goal of this study was to develop and evaluate texture features, determined from planning computed tomography (CT) data, to classify the spatial distribution of FT in the breast. Planning CT data of 23 patients were evaluated in this study. Texture features were derived from the radial glandular fraction (RGF), which described the distribution of FT within three breast regions (posterior, middle, and anterior). Using visual assessment, experts grouped patients according to FT spatial distribution: sparse or non-sparse. Differences in the features between the two groups were investigated using the Wilcoxon rank test. Classification performance of the features was evaluated for a range of support vector machine (SVM) classifiers. Experts found eight patients and 15 patients had sparse and non-sparse spatial distribution of FT, respectively. A large proportion of features (>9 of 13) from the individual breast regions had significant differences (p <0.05) between the sparse and non-sparse group. The features from middle region had most significant differences and gave the highest classification accuracy for all the SVM kernels investigated. Overall, the features from middle breast region achieved highest accuracy (91 %) with the linear SVM kernel. This study found that features based on radial glandular fraction provide a means for discriminating between fibroglandular tissue distributions and could achieve a classification accuracy of 91 %

  5. Absorbed doses behind bones with MR image-based dose calculations for radiotherapy treatment planning.

    Science.gov (United States)

    Korhonen, Juha; Kapanen, Mika; Keyrilainen, Jani; Seppala, Tiina; Tuomikoski, Laura; Tenhunen, Mikko

    2013-01-01

    Magnetic resonance (MR) images are used increasingly in external radiotherapy target delineation because of their superior soft tissue contrast compared to computed tomography (CT) images. Nevertheless, radiotherapy treatment planning has traditionally been based on the use of CT images, due to the restrictive features of MR images such as lack of electron density information. This research aimed to measure absorbed radiation doses in material behind different bone parts, and to evaluate dose calculation errors in two pseudo-CT images; first, by assuming a single electron density value for the bones, and second, by converting the electron density values inside bones from T(1)∕T(2)∗-weighted MR image intensity values. A dedicated phantom was constructed using fresh deer bones and gelatine. The effect of different bone parts to the absorbed dose behind them was investigated with a single open field at 6 and 15 MV, and measuring clinically detectable dose deviations by an ionization chamber matrix. Dose calculation deviations in a conversion-based pseudo-CT image and in a bulk density pseudo-CT image, where the relative electron density to water for the bones was set as 1.3, were quantified by comparing the calculation results with those obtained in a standard CT image by superposition and Monte Carlo algorithms. The calculations revealed that the applied bulk density pseudo-CT image causes deviations up to 2.7% (6 MV) and 2.0% (15 MV) to the dose behind the examined bones. The corresponding values in the conversion-based pseudo-CT image were 1.3% (6 MV) and 1.0% (15 MV). The examinations illustrated that the representation of the heterogeneous femoral bone (cortex denser compared to core) by using a bulk density for the whole bone causes dose deviations up to 2% both behind the bone edge and the middle part of the bone (diameter bones). This study indicates that the decrease in absorbed dose is not dependent on the bone diameter with all types of bones. Thus

  6. MRI-based measurements of respiratory motion variability and assessment of imaging strategies for radiotherapy planning

    Science.gov (United States)

    Blackall, J. M.; Ahmad, S.; Miquel, M. E.; McClelland, J. R.; Landau, D. B.; Hawkes, D. J.

    2006-09-01

    Respiratory organ motion has a significant impact on the planning and delivery of radiotherapy (RT) treatment for lung cancer. Currently widespread techniques, such as 4D-computed tomography (4DCT), cannot be used to measure variability of this motion from one cycle to the next. In this paper, we describe the use of fast magnetic resonance imaging (MRI) techniques to investigate the intra- and inter-cycle reproducibility of respiratory motion and also to estimate the level of errors that may be introduced into treatment delivery by using various breath-hold imaging strategies during lung RT planning. A reference model of respiratory motion is formed to enable comparison of different breathing cycles at any arbitrary position in the respiratory cycle. This is constructed by using free-breathing images from the inhale phase of a single breathing cycle, then co-registering the images, and thereby tracking landmarks. This reference model is then compared to alternative models constructed from images acquired during the exhale phase of the same cycle and the inhale phase of a subsequent cycle, to assess intra- and inter-cycle variability ('hysteresis' and 'reproducibility') of organ motion. The reference model is also compared to a series of models formed from breath-hold data at exhale and inhale. Evaluation of these models is carried out on data from ten healthy volunteers and five lung cancer patients. Free-breathing models show good levels of intra- and inter-cycle reproducibility across the tidal breathing range. Mean intra-cycle errors in the position of organ surface landmarks of 1.5(1.4)-3.5(3.3) mm for volunteers and 2.8(1.8)-5.2(5.2) mm for patients. Equivalent measures of inter-cycle variability across this range are 1.7(1.0)-3.9(3.3) mm for volunteers and 2.8(1.8)-3.3(2.2) mm for patients. As expected, models based on breath-hold sequences do not represent normal tidal motion as well as those based on free-breathing data, with mean errors of 4

  7. Quantitative dosimetric assessment for effect of gold nanoparticles as contrast media on radiotherapy planning

    Science.gov (United States)

    Tu, Shu-Ju; Yang, Pei-Ying; Hong, Ji-Hong; Lo, Ching-Jung

    2013-07-01

    In CT planning for radiation therapy, patients may be asked to have a medical procedure of contrast agent (CA) administration as required by their physicians. CA media improve quality of CT images and assist radiation oncologists in delineation of the target or organs with accuracy. However, dosimetric discrepancy may occur between scenarios in which CA media are present in CT planning and absent in treatment delivery. In recent preclinical experiments of small animals, gold nanoparticles (AuNPs) have been identified as an excellent contrast material of x-ray imaging. In this work, we quantitatively evaluate the effect of AuNPs to be used as a potential material of contrast enhancement in radiotherapy planning with an analytical phantom and clinical case. Conray 60, an iodine-based product for contrast enhancement in clinical uses, is included as a comparison. Other additional variables such as different concentrations of CA media, radiation delivery techniques and dose calculation algorithms are included. We consider 1-field AP, 4-field box, 7-field intensity modulated radiation therapy (IMRT) and a recent technique of volumetric modulated arc therapy (VMAT). CA media of AuNPs (Conray 60) with concentrations of 10%, 20%, 30%, 40% and 50% containing 28.2, 56.4, 84.6, 112.8 and 141.0 mg of gold (iodine) per mL were prepared prior to CT scanning. A virtual phantom with a target where nanoparticle media are loaded and clinical case of gastric lymphoma in which the Conray 60 media were given to the patient prior to the CT planning are included for the study. Compared to Conray 60 media with concentration of 10%/50%, Hounsfield units for AuNP media of 10%/50% are 322/1608 higher due to the fact that atomic number of Au (Z=79) is larger than I (Z=53). In consequence, dosimetric discrepancy of AuNPs is magnified between presence and absence of contrast media. It was found in the phantom study that percent dose differences between presence and absence of CA media may be

  8. MRI-based measurements of respiratory motion variability and assessment of imaging strategies for radiotherapy planning

    International Nuclear Information System (INIS)

    Blackall, J M; Ahmad, S; Miquel, M E; McClelland, J R; Landau, D B; Hawkes, D J

    2006-01-01

    Respiratory organ motion has a significant impact on the planning and delivery of radiotherapy (RT) treatment for lung cancer. Currently widespread techniques, such as 4D-computed tomography (4DCT), cannot be used to measure variability of this motion from one cycle to the next. In this paper, we describe the use of fast magnetic resonance imaging (MRI) techniques to investigate the intra- and inter-cycle reproducibility of respiratory motion and also to estimate the level of errors that may be introduced into treatment delivery by using various breath-hold imaging strategies during lung RT planning. A reference model of respiratory motion is formed to enable comparison of different breathing cycles at any arbitrary position in the respiratory cycle. This is constructed by using free-breathing images from the inhale phase of a single breathing cycle, then co-registering the images, and thereby tracking landmarks. This reference model is then compared to alternative models constructed from images acquired during the exhale phase of the same cycle and the inhale phase of a subsequent cycle, to assess intra- and inter-cycle variability ('hysteresis' and 'reproducibility') of organ motion. The reference model is also compared to a series of models formed from breath-hold data at exhale and inhale. Evaluation of these models is carried out on data from ten healthy volunteers and five lung cancer patients. Free-breathing models show good levels of intra- and inter-cycle reproducibility across the tidal breathing range. Mean intra-cycle errors in the position of organ surface landmarks of 1.5(1.4)-3.5(3.3) mm for volunteers and 2.8(1.8)-5.2(5.2) mm for patients. Equivalent measures of inter-cycle variability across this range are 1.7(1.0)-3.9(3.3) mm for volunteers and 2.8(1.8)-3.3(2.2) mm for patients. As expected, models based on breath-hold sequences do not represent normal tidal motion as well as those based on free-breathing data, with mean errors of 4

  9. Energy Dependence of Measured CT Numbers on Substituted Materials Used for CT Number Calibration of Radiotherapy Treatment Planning Systems.

    Directory of Open Access Journals (Sweden)

    Reza Mahmoudi

    Full Text Available For accurate dose calculations, it is necessary to provide a correct relationship between the CT numbers and electron density in radiotherapy treatment planning systems (TPSs. The purpose of this study was to investigate the energy dependence of measured CT numbers on substituted materials used for CT number calibration of radiotherapy TPSs and the resulting errors in the treatment planning calculation doses.In this study, we designed a cylindrical water phantom with different materials used as tissue equivalent materials for the simulation of tissues and obtaining the related CT numbers. For evaluating the effect of CT number variations of substituted materials due to energy changing of scanner (kVp on the dose calculation of TPS, the slices of the scanned phantom at three kVp's were imported into the desired TPSs (MIRS and CorePLAN. Dose calculations were performed on two TPSs.The mean absolute percentage differences between the CT numbers of CT scanner and two treatment planning systems for all the samples were 3.22%±2.57% for CorePLAN and 2.88%±2.11% for MIRS. It was also found that the maximum absolute percentage difference between all of the calculated doses from each photon beam of linac (6 and 15 MV at three kVp's was less than 1.2%.The present study revealed that, for the materials with effective low atomic number, the mean CT number increased with increasing energy, which was opposite for the materials with an effective high atomic number. We concluded that the tissue substitute materials had a different behavior in the energy ranges from 80 to 130 kVp. So, it is necessary to consider the energy dependence of the substitute materials used for the measurement or calibration of CT number for radiotherapy treatment planning systems.

  10. Intraoperative avidination for radionuclide treatment as a radiotherapy boost in breast cancer: results of a phase II study with {sup 90}Y-labeled biotin

    Energy Technology Data Exchange (ETDEWEB)

    Paganelli, Giovanni; De Cicco, Concetta; Carbone, Giuseppe; Pacifici, Monica [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Ferrari, Mahila E.; Cremonesi, Marta; Di Dia, Amalia [European Institute of Oncology, Division of Medical Physics, Milan (Italy); Pagani, Gianmatteo; Galimberti, Viviana; Luini, Alberto [European Institute of Oncology, Division of Senology, Milan (Italy); Leonardi, Maria Cristina; Ferrari, Annamaria; Orecchia, Roberto [European Institute of Oncology, Division of Radiotherapy, Milan (Italy); De Santis, Rita [Sigma-Tau SpA R and D, Rome (Italy); Zurrida, Stefano [European Institute of Oncology, Division of Senology, Milan (Italy); University of Milan School of Medicine, Milan (Italy); Veronesi, Umberto [European Institute of Oncology, Scientific Director, Milan (Italy)

    2010-02-15

    External beam radiotherapy (EBRT) after conservative surgery for early breast cancer requires 5-7 weeks. For elderly patients and those distant from an RT center, attending for EBRT may be difficult or impossible. We investigated local toxicity, cosmetic outcomes, and quality of life in a new breast irradiation technique - intraoperative avidination for radionuclide therapy (IART) - in which avidin is administered to the tumor bed and {sup 90}Y-labelled biotin later administered intravenously to bind the avidin and provide irradiation. Reduced duration EBRT (40 Gy) is given subsequently. After surgery, 50 (ten patients), 100 (15 patients) or 150 mg (ten patients) of avidin was injected into the tumor bed. After 12-24 h, 3.7 GBq {sup 90}Y-biotin (beta source for therapeutic effect) plus 185 MBq {sup 111}In-biotin (gamma source for imaging and dosimetry) was infused slowly. Whole-body scintigraphy and SPECT/CT images were taken for up to 30 h. Shortened EBRT started 4 weeks later. Local toxicity was assessed by RTOG scale; quality of life was assessed by EORTC QOL-30. Of 35 patients recruited (mean age 63 years; range 42-74) 32 received IART plus EBRT. 100 mg avidin provided 19.5 {+-} 4.0 Gy to the tumor bed and was considered the optimum dose. No side-effects of avidin or {sup 90}Y-biotin occurred, with no hematological or local toxicity. Local G3 toxicity occurred in 3/32 patients during EBRT. IART plus EBRT was well accepted, with good cosmetic outcomes and maintained quality of life. IART plus reduced EBRT can accelerate irradiation after conservative breast surgery. (orig.)

  11. Intraoperative avidination for radionuclide treatment as a radiotherapy boost in breast cancer: results of a phase II study with 90Y-labeled biotin

    International Nuclear Information System (INIS)

    Paganelli, Giovanni; De Cicco, Concetta; Carbone, Giuseppe; Pacifici, Monica; Ferrari, Mahila E.; Cremonesi, Marta; Di Dia, Amalia; Pagani, Gianmatteo; Galimberti, Viviana; Luini, Alberto; Leonardi, Maria Cristina; Ferrari, Annamaria; Orecchia, Roberto; De Santis, Rita; Zurrida, Stefano; Veronesi, Umberto

    2010-01-01

    External beam radiotherapy (EBRT) after conservative surgery for early breast cancer requires 5-7 weeks. For elderly patients and those distant from an RT center, attending for EBRT may be difficult or impossible. We investigated local toxicity, cosmetic outcomes, and quality of life in a new breast irradiation technique - intraoperative avidination for radionuclide therapy (IART) - in which avidin is administered to the tumor bed and 90 Y-labelled biotin later administered intravenously to bind the avidin and provide irradiation. Reduced duration EBRT (40 Gy) is given subsequently. After surgery, 50 (ten patients), 100 (15 patients) or 150 mg (ten patients) of avidin was injected into the tumor bed. After 12-24 h, 3.7 GBq 90 Y-biotin (beta source for therapeutic effect) plus 185 MBq 111 In-biotin (gamma source for imaging and dosimetry) was infused slowly. Whole-body scintigraphy and SPECT/CT images were taken for up to 30 h. Shortened EBRT started 4 weeks later. Local toxicity was assessed by RTOG scale; quality of life was assessed by EORTC QOL-30. Of 35 patients recruited (mean age 63 years; range 42-74) 32 received IART plus EBRT. 100 mg avidin provided 19.5 ± 4.0 Gy to the tumor bed and was considered the optimum dose. No side-effects of avidin or 90 Y-biotin occurred, with no hematological or local toxicity. Local G3 toxicity occurred in 3/32 patients during EBRT. IART plus EBRT was well accepted, with good cosmetic outcomes and maintained quality of life. IART plus reduced EBRT can accelerate irradiation after conservative breast surgery. (orig.)

  12. Modification of a three-dimensional treatment planning system for the use of multi-leaf collimators in conformation radiotherapy

    International Nuclear Information System (INIS)

    Boesecke, R.; Becker, G.; Alandt, K.; Pastyr, O.; Doll, J.; Schlegel, W.; Lorenz, W.J.

    1991-01-01

    The multi-leaf collimator of the DKFZ is designed as a low cost add-on device for conventional linear accelerators for radiotherapy. The technical specification of the computer controlled collimator is briefly described . A major limitation in the use of the wide capabilities of multi-leaf collimators in the clinic is still an appropriate treatment planning system. This paper describes treatment planning and dose calculation techniques for multi-leaf collimators and shows examples where the capabilities of the collimators are used extensively. (author). 18 refs.; 8 figs.; 2 tabs

  13. Fully Automated Simultaneous Integrated Boosted-Intensity Modulated Radiation Therapy Treatment Planning Is Feasible for Head-and-Neck Cancer: A Prospective Clinical Study

    Energy Technology Data Exchange (ETDEWEB)

    Wu Binbin, E-mail: binbin.wu@gunet.georgetown.edu [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States); Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); McNutt, Todd [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States); Zahurak, Marianna [Department of Oncology Biostatistics, Johns Hopkins University, Baltimore, Maryland (United States); Simari, Patricio [Autodesk Research, Toronto, ON (Canada); Pang, Dalong [Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); Taylor, Russell [Department of Computer Science, Johns Hopkins University, Baltimore, Maryland (United States); Sanguineti, Giuseppe [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States)

    2012-12-01

    Purpose: To prospectively determine whether overlap volume histogram (OVH)-driven, automated simultaneous integrated boosted (SIB)-intensity-modulated radiation therapy (IMRT) treatment planning for head-and-neck cancer can be implemented in clinics. Methods and Materials: A prospective study was designed to compare fully automated plans (APs) created by an OVH-driven, automated planning application with clinical plans (CPs) created by dosimetrists in a 3-dose-level (70 Gy, 63 Gy, and 58.1 Gy), head-and-neck SIB-IMRT planning. Because primary organ sparing (cord, brain, brainstem, mandible, and optic nerve/chiasm) always received the highest priority in clinical planning, the study aimed to show the noninferiority of APs with respect to PTV coverage and secondary organ sparing (parotid, brachial plexus, esophagus, larynx, inner ear, and oral mucosa). The sample size was determined a priori by a superiority hypothesis test that had 85% power to detect a 4% dose decrease in secondary organ sparing with a 2-sided alpha level of 0.05. A generalized estimating equation (GEE) regression model was used for statistical comparison. Results: Forty consecutive patients were accrued from July to December 2010. GEE analysis indicated that in APs, overall average dose to the secondary organs was reduced by 1.16 (95% CI = 0.09-2.33) with P=.04, overall average PTV coverage was increased by 0.26% (95% CI = 0.06-0.47) with P=.02 and overall average dose to the primary organs was reduced by 1.14 Gy (95% CI = 0.45-1.8) with P=.004. A physician determined that all APs could be delivered to patients, and APs were clinically superior in 27 of 40 cases. Conclusions: The application can be implemented in clinics as a fast, reliable, and consistent way of generating plans that need only minor adjustments to meet specific clinical needs.

  14. Treatment planning comparison of electron arc therapy and photon intensity modulated radiotherapy for Askin's tumor of chest wall

    International Nuclear Information System (INIS)

    Jamema, Swamidas V.; Sharma, Pramod K.; Laskar, Siddhartha; Deshpande, Deepak D.; Shrivastava, Shyam K.

    2007-01-01

    Background and Purpose: A dosimetric study to quantitatively compare radiotherapy treatment plans for Askin's tumor using Electron Arc (EA) vs. photon Intensity Modulated Radiotherapy (IMRT). Materials and methods: Five patients treated with EA were included in this study. Treatment plans were generated for each patient using EA and IMRT. Plans were compared using dose volume histograms (DVH) of the Planning Target Volume (PTV) and Organs at Risk (OAR). Results: IMRT resulted in superior PTV coverage, and homogeneous dose distribution compared to EA. For EA, 92% of the PTV was covered to 85% of the dose compared to IMRT in which 96% was covered to 95% of the dose. V 107 that represents the hot spot within the PTV was more in IMRT compared to EA: 7.4(±2)% vs. 3(±0.5)%, respectively. With PTVs located close to the spinal cord (SC), the dose to SC was more with EA, whereas for PTVs located away from the SC, the dose to SC was more with IMRT. The cardiac dose profile was similar to that of SC. Ipsilateral lung received lower doses with IMRT while contralateral lung received higher dose with IMRT compared to EA. For non-OAR normal tissues, IMRT resulted in large volumes of low dose regions. Conclusions: IMRT resulted in superior PTV coverage and sparing of OAR compared to EA plans. Although IMRT seems to be superior to EA, one needs to keep in mind the volume of low dose regions associated with IMRT, especially while treating young children

  15. Radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Boljesikova, E.; Ligacova, A.

    2012-01-01

    Radiotherapy plays an important role in the treatment of breast carcinoma, reduces local recurrences about 20% (after breast conserving surgery or mastectomy), reduces 15 y mortality for cancer about 5%. The irradiation volumes can cover whole breast ± boost, partial breast, chest wall and regional lymph nodes. In contribution are analysed indications of radiotherapy, radiation techniques with focus on new trends, altered fractionation, partial breast irradiation and toxicity. (author)

  16. Inclusion of geometrical uncertainties in radiotherapy treatment planning by means of coverage probability

    International Nuclear Information System (INIS)

    Stroom, Joep C.; Boer, Hans C.J. de; Huizenga, Henk; Visser, Andries G.

    1999-01-01

    Purpose: Following the ICRU-50 recommendations, geometrical uncertainties in tumor position during radiotherapy treatments are generally included in the treatment planning by adding a margin to the clinical target volume (CTV) to yield the planning target volume (PTV). We have developed a method for automatic calculation of this margin. Methods and Materials: Geometrical uncertainties of a specific patient group can normally be characterized by the standard deviation of the distribution of systematic deviations in the patient group (Σ) and by the average standard deviation of the distribution of random deviations (σ). The CTV of a patient to be planned can be represented in a 3D matrix in the treatment room coordinate system with voxel values one inside and zero outside the CTV. Convolution of this matrix with the appropriate probability distributions for translations and rotations yields a matrix with coverage probabilities (CPs) which is defined as the probability for each point to be covered by the CTV. The PTV can then be chosen as a volume corresponding to a certain iso-probability level. Separate calculations are performed for systematic and random deviations. Iso-probability volumes are selected in such a way that a high percentage of the CTV volume (on average > 99%) receives a high dose (> 95%). The consequences of systematic deviations on the dose distribution in the CTV can be estimated by calculation of dose histograms of the CP matrix for systematic deviations, resulting in a so-called dose probability histogram (DPH). A DPH represents the average dose volume histogram (DVH) for all systematic deviations in the patient group. The consequences of random deviations can be calculated by convolution of the dose distribution with the probability distributions for random deviations. Using the convolved dose matrix in the DPH calculation yields full information about the influence of geometrical uncertainties on the dose in the CTV. Results: The model is

  17. A hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

    International Nuclear Information System (INIS)

    Lei Yu; Wu Qiuwen

    2010-01-01

    Offline adaptive radiotherapy (ART) has been used to effectively correct and compensate for prostate motion and reduce the required margin. The efficacy depends on the characteristics of the patient setup error and interfraction motion through the whole treatment; specifically, systematic errors are corrected and random errors are compensated for through the margins. In online image-guided radiation therapy (IGRT) of prostate cancer, the translational setup error and inter-fractional prostate motion are corrected through pre-treatment imaging and couch correction at each fraction. However, the rotation and deformation of the target are not corrected and only accounted for with margins in treatment planning. The purpose of this study was to investigate whether the offline ART strategy is necessary for an online IGRT protocol and to evaluate the benefit of the hybrid strategy. First, to investigate the rationale of the hybrid strategy, 592 cone-beam-computed tomography (CBCT) images taken before and after each fraction for an online IGRT protocol from 16 patients were analyzed. Specifically, the characteristics of prostate rotation were analyzed. It was found that there exist systematic inter-fractional prostate rotations, and they are patient specific. These rotations, if not corrected, are persistent through the treatment fraction, and rotations detected in early fractions are representative of those in later fractions. These findings suggest that the offline adaptive replanning strategy is beneficial to the online IGRT protocol with further margin reductions. Second, to quantitatively evaluate the benefit of the hybrid strategy, 412 repeated helical CT scans from 25 patients during the course of treatment were included in the replanning study. Both low-risk patients (LRP, clinical target volume, CTV = prostate) and intermediate-risk patients (IRP, CTV = prostate + seminal vesicles) were included in the simulation. The contours of prostate and seminal vesicles were

  18. Parotid Gland Dose in Intensity-Modulated Radiotherapy for Head and Neck Cancer: Is What You Plan What You Get?

    International Nuclear Information System (INIS)

    O'Daniel, Jennifer C.; Garden, Adam S.; Schwartz, David L.; Wang He; Ang, Kian K.; Ahamad, Anesa; Rosenthal, David I.; Morrison, William H.; Asper, Joshua A.; Zhang Lifei; Tung Shihming; Mohan, Radhe; Dong Lei

    2007-01-01

    Purpose: To quantify the differences between planned and delivered parotid gland and target doses, and to assess the benefits of daily bone alignment for head and neck cancer patients treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: Eleven head and neck cancer patients received two CT scans per week with an in-room CT scanner over the course of their radiotherapy. The clinical IMRT plans, designed with 3-mm to 4-mm planning margins, were recalculated on the repeat CT images. The plans were aligned using the actual treatment isocenter marked with radiopaque markers (BB) and bone alignment to the cervical vertebrae to simulate image-guided setup. In-house deformable image registration software was used to map daily dose distributions to the original treatment plan and to calculate a cumulative delivered dose distribution for each patient. Results: Using conventional BB alignment led to increases in the parotid gland mean dose above the planned dose by 5 to 7 Gy in 45% of the patients (median, 3.0 Gy ipsilateral, p = 0.026; median, 1.0 Gy contralateral, p = 0.016). Use of bone alignment led to reductions relative to BB alignment in 91% of patients (median, 2 Gy; range, 0.3-8.3 Gy; 15 of 22 parotids improved). However, the parotid dose from bone alignment was still greater than planned (median, 1.0 Gy, p = 0.007). Neither approach affected tumor dose coverage. Conclusions: With conventional BB alignment, the parotid gland mean dose was significantly increased above the planned mean dose. Using daily bone alignment reduced the parotid dose compared with BB alignment in almost all patients. A 3- to 4-mm planning margin was adequate for tumor dose coverage

  19. Impact of 18F-fluoro-2-deoxyglucose positron emission tomography on treatment strategy and radiotherapy planning for stage I-II Hodgkin disease: a prospective multicenter study.

    Science.gov (United States)

    Pommier, Pascal; Dussart, Sophie; Girinsky, Théodore; Chabaud, Sylvie; Lagrange, Jean Leon; Nguyen, Tan Dat; Beckendorff, Véronique; D'Hombres, Anne; Artignan, Xavier; Bondiau, Pierre Yves; Carrie, Christian; Giammarile, Francesco

    2011-03-01

    To quantify the impact of preradiotherapy 18F-fluoro-2-deoxyglucose positron-emission tomography (FDG-PET) on treatment strategy and radiotherapy planning for patients with Stage I/II Hodgkin disease included in a large prospective multicenter study. Conventional computed tomography and FDG-PET were performed just before the planned radiotherapy. The radiotherapy plan was first elaborated under blinded conditions for FDG-PET data. Then, the medical staff was asked to confirm or not confirm the treatment strategy and, if appropriate, to modify the radiotherapy plan based on additional information from FDG-PET. Between January 2004 and January 2006, 137 patients were included (124 were available for analysis) in 11 centers (108 adults, 16 children). All but 1 patient had received chemotherapy before inclusion. Prechemotherapy work-up included FDG-PET for 61 patients, and data were available for elaboration of the first radiotherapy plan. Based on preradiotherapy FDG-PET data, the radiotherapy was cancelled in 6 patients (4.8%), and treatment plan modifications occurred in 16 patients (12.9%): total dose (11 patients), CTV volume (5 patients), number of beam incidences (6 patients), and number of CTV (6 patients). The concordance between the treatment strategies with or without preradiotherapy FDG-PET was 82.3%. Concordance results were not significantly different when prechemotherapy PET-CT information was available. Preradiotherapy FDG-PET for treatment planning in Hodgkin lymphoma may lead to significant modification of the treatment strategy and the radiotherapy planning in patients with Stage I or II Hodgkin disease, even in those who have undergone FDG-PET as part of the prechemotherapy work-up. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Feasibility of preference-driven radiotherapy dose treatment planning to support shared decision making in anal cancer

    DEFF Research Database (Denmark)

    Rønde, Heidi S; Wee, Leonard; Pløen, John

    2017-01-01

    PURPOSE/OBJECTIVE: Chemo-radiotherapy is an established primary curative treatment for anal cancer, but clinically equal rationale for different target doses exists. If joint preferences (physician and patient) are used to determine acceptable tradeoffs in radiotherapy treatment planning, multiple.......7%-points; (0.3; 30.6); p preference [median change in V35Gy: 30.3%-points; (12.4; 43.1); p preferences, although tradeoffs are highly patient-dependent. This study demonstrates...... were generated for 22 anal cancer patients. Multi-criteria optimization handles dynamically changing priorities between clinical objectives while meeting fixed clinical constraints. Four unique dose distributions were designed to represent a wide span of clinically relevant objectives: high...

  1. Dosimetric and geometric evaluation of a hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

    Science.gov (United States)

    Liu, Han; Wu, Qiuwen

    2011-01-01

    For prostate cancer patients, online image-guided (IG) radiotherapy has been widely used in clinic to correct the translational inter-fractional motion at each treatment fraction. For uncertainties that cannot be corrected online, such as rotation and deformation of the target volume, margins are still required to be added to the clinical target volume (CTV) for the treatment planning. Offline adaptive radiotherapy has been implemented to optimize the treatment for each individual patient based on the measurements at early stages of treatment process. It has been shown that offline adaptive radiotherapy can effectively reduce the required margin. Recently a hybrid strategy of offline adaptive replanning and online IG was proposed and the geometric evaluation was performed. It was found that the planning margins can be further reduced by 1–2 mm compared to online IG only strategy. The purpose of this study was to investigate the dosimetric benefits of such hybrid strategy on the target and organs at risk (OARs). A total of 420 repeated helical computed tomography (HCT) scans from 28 patients were included in the study. Both low-risk patients (LRP, CTV = prostate) and intermediate-risk patients (IRP, CTV = prostate + seminal vesicles, SV) were included in the simulation. Two registration methods, based on center-of-mass (COM) shift of prostate only and prostate plus SV, were performed for IRP. The intensity modulated radiotherapy (IMRT) was used in the simulation. Criteria on both cumulative dose and fractional doses were evaluated. Furthermore, the geometric evaluation was extended to investigate the optimal number of fractions necessary to construct the internal target volume (ITV) for the hybrid strategy. The dosimetric margin improvement was smaller than its geometric counterpart and was in the range of 0 mm to 1 mm. The optimal number of fractions necessary for the ITV construction is 2 for LRP and 3–4 for IRP in a hypofractionation protocol. A new

  2. A strategy for multimodal deformable image registration to integrate PET/MR into radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Leibfarth, Sara; Moennich, David; Thorwarth, Daniela; Welz, Stefan; Siegel, Christine; Zips, Daniel; Schwenzer, Nina; Holger Schmidt, Holger

    2013-01-01

    Background: Combined positron emission tomography (PET)/magnetic resonance imaging (MRI) is highly promising for biologically individualized radiotherapy (RT). Hence, the purpose of this work was to develop an accurate and robust registration strategy to integrate combined PET/MR data into RT treatment planning. Material and methods: Eight patient datasets consisting of an FDG PET/computed tomography (CT) and a subsequently acquired PET/MR of the head and neck (HN) region were available. Registration strategies were developed based on CT and MR data only, whereas the PET components were fused with the resulting deformation field. Following a rigid registration, deformable registration was performed with a transform parametrized by B-splines. Three different optimization metrics were investigated: global mutual information (GMI), GMI combined with a bending energy penalty (BEP) for regularization (GMI + BEP) and localized mutual information with BEP (LMI + BEP). Different quantitative registration quality measures were developed, including volumetric overlap and mean distance measures for structures segmented on CT and MR as well as anatomical landmark distances. Moreover, the local registration quality in the tumor region was assessed by the normalized cross correlation (NCC) of the two PET datasets. Results: LMI + BEP yielded the most robust and accurate registration results. For GMI, GMI + BEP and LMI + BEP, mean landmark distances (standard deviations) were 23.9 mm (15.5 mm), 4.8 mm (4.0 mm) and 3.0 mm (1.0 mm), and mean NCC values (standard deviations) were 0.29 (0.29), 0.84 (0.14) and 0.88 (0.06), respectively. Conclusion: Accurate and robust multimodal deformable image registration of CT and MR in the HN region can be performed using a B-spline parametrized transform and LMI + BEP as optimization metric. With this strategy, biologically individualized RT based on combined PET/MRI in terms of dose painting is possible

  3. MRI sequences for the detection of individual lymph nodes in regional breast radiotherapy planning.

    Science.gov (United States)

    van Heijst, Tristan C F; van Asselen, Bram; Pijnappel, Ruud M; Cloos-van Balen, Marissa; Lagendijk, Jan J W; van den Bongard, Desirée; Philippens, Mariëlle E P

    2016-07-01

    In regional radiotherapy (RT) for patients with breast cancer, lymph node (LN) targets are delineated on CT, defined by anatomical boundaries. By identifying individual LNs, MRI-based delineations may reduce target volumes and thereby toxicity. We optimized MRI sequences for this purpose. Our aim was to evaluate the techniques for LN delineation in RT planning. Supine MRI was explored at 1.5 T in RT position (arms in abduction). 5 MRI techniques were optimized in 10 and evaluated in 12 healthy female volunteers. The scans included one T1 weighted (T1w), three T2 weighted (T2w) and a diffusion-weighted imaging (DWI) technique. Quantitative evaluation was performed by scoring LN numbers per volunteer and per scan. Qualitatively, scans were assessed on seven aspects, including LN contrast, anatomical information and insensitivity to motion during acquisition. Two T2w fast spin-echo (FSE) methods showed the highest LN numbers (median 24 axillary), high contrast, excellent fat suppression and relative insensitivity to motion during acquisition. A third T2w sequence and DWI showed significantly fewer LNs (14 and 10) and proved unsuitable due to motion sensitivity and geometrical uncertainties. T1w MRI showed an intermediate number of LNs (17), provided valuable anatomical information, but lacked LN contrast. Explicit LN imaging was achieved, in supine RT position, using MRI. Two T2w FSE techniques had the highest detection rates and were motion insensitive. T1w MRI showed anatomical information. MRI enables direct delineation of individual LNs. Our optimized MRI scans enable accurate target definition in MRI-guided regional breast RT and development of personalized treatments.

  4. A preliminary comparative treatment planning study for radiotherapy of age-related maculopathy

    International Nuclear Information System (INIS)

    Mazal, A.; Schwartz, L.; Lacroix, F.; Mammar, H.; Delacroix, S.; Ferrand, R.; Nauraye, C.; Desjardins, L.; Schlienger, P.; D'Hermies, F.; Frau, E.; Habrand, J.-L.; Rosenwald, J.-C.

    1998-01-01

    Purpose: We present a comparative planning of different approaches for external radiotherapy in age-related maculopathies. Materials and methods: Calculated dose distributions and dose-volume histograms for (a) bilateral irradiation with 6 MV photons, (b) a single lateral-oblique beam using either photons, electrons or protons and (c) an anterior circular proton beam. Results: For lateral photon or electron beams the dose to the lens is usually lower than 10% of the dose to the macula. The entrance doses for bilateral photon beams are about 50% which increase up to 100% at the orbital bone. About 5 mm of optic nerves are irradiated at the maximal dose while the optic chiasma is spared. A single photon beam gives 50% of the dose to the fellow eye. The electron beam spares the fellow eye but gives a rather inhomogeneous dose to the target volume. For a lateral proton beam, 4 mm of optic nerve receives 90% of the dose, the skin dose is at least 70% of the dose to the macula and the lens and the fellow eye are spared. An anterior proton beam gives 90% of the dose to 1 mm of optic nerve and the 50% isodose approaches the periphery of the lens. Conclusion: Doses to the critical structures can be dramatically diminished for all the techniques by reducing the beam size, but only if very precise set-up techniques are used. Proton beams are an attractive solution, but the impact of such a choice on the use of proton facilities and on the national health system should be carefully evaluated, as well as the risk of radio-induced secondary neoplasias. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Is Planned Neck Dissection Necessary for Head and Neck Cancer After Intensity-Modulated Radiotherapy?

    International Nuclear Information System (INIS)

    Yao Min; Hoffman, Henry T.; Chang, Kristi; Funk, Gerry F.; Smith, Russell B.; Tan Huaming; Clamon, Gerald H.; Dornfeld, Ken; Buatti, John M.

    2007-01-01

    Purpose: The objective of this study was to determine regional control of local regional advanced head and neck squamous cell carcinoma (HNSCC) treated with intensity-modulated radiotherapy (IMRT), along with the role and selection criteria for neck dissection after IMRT. Methods and Materials: A total of 90 patients with stage N2A or greater HNSCC were treated with definitive IMRT from December 1999 to July 2005. Three clinical target volumes were defined and were treated to 70 to 74 Gy, 60 Gy, and 54 Gy, respectively. Neck dissection was performed for selected patients after IMRT. Selection criteria evolved during this period with emphasis on post-IMRT [ 18 F] fluorodeoxyglucose positron emission tomography in recent years. Results: Median follow-up for all patients was 29 months (range, 0.2-74 months). All living patients were followed at least 9 months after completing treatment. Thirteen patients underwent neck dissection after IMRT because of residual lymphadenopathy. Of these, 6 contained residual viable tumor. Three patients with persistent adenopathy did not undergo neck dissection: 2 refused and 1 had lung metastasis. Among the remaining 74 patients who were observed without neck dissection, there was only 1 case of regional failure. Among all 90 patients in this study, the 3-year local and regional control was 96.3% and 95.4%, respectively. Conclusions: Appropriately delivered IMRT has excellent dose coverage for cervical lymph nodes. A high radiation dose can be safely delivered to the abnormal lymph nodes. There is a high complete response rate. Routine planned neck dissection for patients with N2A and higher stage after IMRT is not necessary. Post-IMRT [ 18 F] fluorodeoxyglucose positron emission tomography is a useful tool in selecting patients appropriate for neck dissection

  6. SU-F-BRB-07: A Plan Comparison Tool to Ensure Robustness and Deliverability in Online-Adaptive Radiotherapy

    International Nuclear Information System (INIS)

    Hill, P; Labby, Z; Bayliss, R A; Geurts, M; Bayouth, J

    2015-01-01

    Purpose: To develop a plan comparison tool that will ensure robustness and deliverability through analysis of baseline and online-adaptive radiotherapy plans using similarity metrics. Methods: The ViewRay MRIdian treatment planning system allows export of a plan file that contains plan and delivery information. A software tool was developed to read and compare two plans, providing information and metrics to assess their similarity. In addition to performing direct comparisons (e.g. demographics, ROI volumes, number of segments, total beam-on time), the tool computes and presents histograms of derived metrics (e.g. step-and-shoot segment field sizes, segment average leaf gaps). Such metrics were investigated for their ability to predict that an online-adapted plan reasonably similar to a baseline plan where deliverability has already been established. Results: In the realm of online-adaptive planning, comparing ROI volumes offers a sanity check to verify observations found during contouring. Beyond ROI analysis, it has been found that simply editing contours and re-optimizing to adapt treatment can produce a delivery that is substantially different than the baseline plan (e.g. number of segments increased by 31%), with no changes in optimization parameters and only minor changes in anatomy. Currently the tool can quickly identify large omissions or deviations from baseline expectations. As our online-adaptive patient population increases, we will continue to develop and refine quantitative acceptance criteria for adapted plans and relate them historical delivery QA measurements. Conclusion: The plan comparison tool is in clinical use and reports a wide range of comparison metrics, illustrating key differences between two plans. This independent check is accomplished in seconds and can be performed in parallel to other tasks in the online-adaptive workflow. Current use prevents large planning or delivery errors from occurring, and ongoing refinements will lead to

  7. Cine Computed Tomography Without Respiratory Surrogate in Planning Stereotactic Radiotherapy for Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Riegel, Adam C. B.A.; Chang, Joe Y.; Vedam, Sastry S.; Johnson, Valen; Chi, Pai-Chun Melinda; Pan, Tinsu

    2009-01-01

    Purpose: To determine whether cine computed tomography (CT) can serve as an alternative to four-dimensional (4D)-CT by providing tumor motion information and producing equivalent target volumes when used to contour in radiotherapy planning without a respiratory surrogate. Methods and Materials: Cine CT images from a commercial CT scanner were used to form maximum intensity projection and respiratory-averaged CT image sets. These image sets then were used together to define the targets for radiotherapy. Phantoms oscillating under irregular motion were used to assess the differences between contouring using cine CT and 4D-CT. We also retrospectively reviewed the image sets for 26 patients (27 lesions) at our institution who had undergone stereotactic radiotherapy for Stage I non-small-cell lung cancer. The patients were included if the tumor motion was >1 cm. The lesions were first contoured using maximum intensity projection and respiratory-averaged CT image sets processed from cine CT and then with 4D-CT maximum intensity projection and 10-phase image sets. The mean ratios of the volume magnitude were compared with intraobserver variation, the mean centroid shifts were calculated, and the volume overlap was assessed with the normalized Dice similarity coefficient index. Results: The phantom studies demonstrated that cine CT captured a greater extent of irregular tumor motion than did 4D-CT, producing a larger tumor volume. The patient studies demonstrated that the gross tumor defined using cine CT imaging was similar to, or slightly larger than, that defined using 4D-CT. Conclusion: The results of our study have shown that cine CT is a promising alternative to 4D-CT for stereotactic radiotherapy planning

  8. The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

    International Nuclear Information System (INIS)

    Henderson, D.L.; Yoo, S.; Kowalok, M.; Mackie, T.R.; Thomadsen, B.R.

    2001-01-01

    The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-meter from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum

  9. The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

    Energy Technology Data Exchange (ETDEWEB)

    D.L. Henderson; S. Yoo; M. Kowalok; T.R. Mackie; B.R. Thomadsen

    2001-10-30

    The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-metere from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum.

  10. Commissioning and implementation of a stereotactic conformal radiotherapy technique using a general‐purpose planning system

    Science.gov (United States)

    Mosleh‐Shirazi, M. Amin; Hansen, Vibeke N.; Childs, Peter J.; Warrington, Alan P.; Saran, Frank H.

    2004-01-01

    The purpose of this paper is to report on commissioning and clinical implementation of a customized system for pediatric stereotactic conformal radiotherapy (SCRT). The system is based on the Pinnacle treatment‐planning system and its interfaces with other equipment: (1) Beam models were optimized for our compact blocking system and a new LINAC. (2) Three CT‐to‐density conversion tables were evaluated, one using tabulated data for a commercial phantom, the second including additional points from the manufacturer's data for the inserts in an in‐house phantom, and the third using measured densities for the in‐house phantom materials combined with tabulated data for the commercial phantom. (3) Blocks were transferred to a computerized block cutter using in‐house software that extracted the block shape from the export file and custom‐fitted the additional necessary shapes. (4) In the absence of a DICOM RT Image link, a method based on screen data capture was used to export digitally reconstructed radiographs (DRRs) to two portal imaging systems for treatment verification. Lens shielding by multileaf collimation in the anterior‐posterior isocenter verification field was investigated. (1) Computed dose distributions using the beam models agreed with measurements well within published acceptability criteria. A difference of up to 1.0 mm was measured between the beam's eye views of aperture blocks and computed 50% isodose contours for a 2×2×2 mm dose calculation grid. (2) The third table, which included measured densities, improved the accuracy of the calculated isocenter dose by up to 0.5% in typical patient SCRT treatments and up to 1.0% in a phantom with 5‐cm diameter inhomogeneity inserts. (3) The block export and customization process was shown to introduce no additional uncertainty. A 1‐mm block production uncertainty was measured using film dosimetry on six blocks. (4) The DRR transfer method did not introduce uncertainty into the process

  11. Commissioning and implementation of a stereotactic conformal radiotherapy technique using a general-purpose planning system.

    Science.gov (United States)

    Mosleh-Shirazi, M Amin; Hansen, Vibeke N; Childs, Peter J; Warrington, Alan P; Saran, Frank H

    2004-01-01

    The purpose of this paper is to report on commissioning and clinical implementation of a customized system for pediatric stereotactic conformal radiotherapy (SCRT). The system is based on the Pinnacle treatment-planning system and its interfaces with other equipment: (1) Beam models were optimized for our compact blocking system and a new LINAC. (2) Three CT-to-density conversion tables were evaluated, one using tabulated data for a commercial phantom, the second including additional points from the manufacturer's data for the inserts in an in-house phantom, and the third using measured densities for the in-house phantom materials combined with tabulated data for the commercial phantom. (3) Blocks were transferred to a computerized block cutter using in-house software that extracted the block shape from the export file and custom-fitted the additional necessary shapes. (4) In the absence of a DICOM RT Image link, a method based on screen data capture was used to export digitally reconstructed radiographs (DRRs) to two portal imaging systems for treatment verification. Lens shielding by multileaf collimation in the anterior-posterior isocenter verification field was investigated. (1) Computed dose distributions using the beam models agreed with measurements well within published acceptability criteria. A difference of up to 1.0 mm was measured between the beam's eye views of aperture blocks and computed 50% isodose contours for a 2 x 2 x 2 mm dose calculation grid. (2) The third table, which included measured densities, improved the accuracy of the calculated isocenter dose by up to 0.5% in typical patient SCRT treatments and up to 1.0% in a phantom with 5-cm diameter inhomogeneity inserts. (3) The block export and customization process was shown to introduce no additional uncertainty. A 1-mm block production uncertainty was measured using film dosimetry on six blocks. (4) The DRR transfer method did not introduce uncertainty into the process. Verification field

  12. SU-E-T-229: Craniospinal Radiotherapy Planning with VMAT, Two First Years Experience

    Energy Technology Data Exchange (ETDEWEB)

    Lliso, F; Carmona, V; Gimeno, J; Candela-Juan, C; Bautista, J [La Fe University and Polytechnic Hospital, Valencia, Valencia (Spain); Richart, J [ITIC, Hospital Clinica Benidorm, Benidorm, Alicante (Spain); Perez-Calatayud, J [La Fe University and Polytechnic Hospital, Valencia, Valencia (Spain); ITIC, Hospital Clinica Benidorm, Benidorm, Alicante (Spain)

    2015-06-15

    Purpose: To describe how we moved to VMAT in the craniospinal radiotherapy planning process, the actual procedure details, and the results for the patients treated. Methods: Twelve patients underwent craniospinal irradiation with the new procedure, based on the paper by Lee et al. (IJROBP 82, 2012), with some additional modifications. Patients were treated in supine position in Varian Clinac iX linacs with 6 MV RapidArc; prescription doses ranged from 23.4 to 40 Gy (13 to 20 fractions); depending on the PTV length, 2 or 3 isocenters were used, all coordinates being equal except the longitudinal one, setting a few centimeter-long overlapping region; 2 arcs (RA) sharing isocentre for the cranial region, RA1 encompassing cranium and superior spinal region, and RA2 intended to improve conformity, only for cranium; for spine, 1 or 2 isocenters were employed; optimization was performed with Eclipse (V 13.0) using AAA algorithm, establishing sets of optimization parameters to give high conformity while sparing OAR. In pediatric patients, homogeneous irradiation of the vertebrae was also required.Conformity (CI) and heterogeneity (HI) indices (same as Lee et al.), and mean and maximum doses for OAR were calculated. Several pre-treatment verification methods were used: Octavius4D (PTW) for each isocentre, point dose at the junction region, Portal Dosimetry (when possible), and independent MU verification software (Diamond, PTW). Results: CI median value was 1.02 (0.99–1.07) and HI, 1.07 (1.06–1.09); a great reduction was observed for CI and OAR mean doses with respect to Lee et al. data; median maximum eye lens dose was 7.3 Gy (4.0–12.0); mean LungV20Gy was 1.9%; in children, vertebrae were homogeneously irradiated (D95%=20.8 Gy, Dmean= 23.2 Gy).All pre-treatment verifications were found within our action levels except for Portal Dosimetry. Conclusion: A RapidArc planning process for craniospinal axis irradiation has been implemented with significant advantages on

  13. SU-F-J-113: Multi-Atlas Based Automatic Organ Segmentation for Lung Radiotherapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J; Han, J; Ailawadi, S; Baker, J; Hsia, A; Xu, Z; Ryu, S [Stony Brook University Hospital, Stony Brook, NY (United States)

    2016-06-15

    Purpose: Normal organ segmentation is one time-consuming and labor-intensive step for lung radiotherapy treatment planning. The aim of this study is to evaluate the performance of a multi-atlas based segmentation approach for automatic organs at risk (OAR) delineation. Methods: Fifteen Lung stereotactic body radiation therapy patients were randomly selected. Planning CT images and OAR contours of the heart - HT, aorta - AO, vena cava - VC, pulmonary trunk - PT, and esophagus – ES were exported and used as reference and atlas sets. For automatic organ delineation for a given target CT, 1) all atlas sets were deformably warped to the target CT, 2) the deformed sets were accumulated and normalized to produce organ probability density (OPD) maps, and 3) the OPD maps were converted to contours via image thresholding. Optimal threshold for each organ was empirically determined by comparing the auto-segmented contours against their respective reference contours. The delineated results were evaluated by measuring contour similarity metrics: DICE, mean distance (MD), and true detection rate (TD), where DICE=(intersection volume/sum of two volumes) and TD = {1.0 - (false positive + false negative)/2.0}. Diffeomorphic Demons algorithm was employed for CT-CT deformable image registrations. Results: Optimal thresholds were determined to be 0.53 for HT, 0.38 for AO, 0.28 for PT, 0.43 for VC, and 0.31 for ES. The mean similarity metrics (DICE[%], MD[mm], TD[%]) were (88, 3.2, 89) for HT, (79, 3.2, 82) for AO, (75, 2.7, 77) for PT, (68, 3.4, 73) for VC, and (51,2.7, 60) for ES. Conclusion: The investigated multi-atlas based approach produced reliable segmentations for the organs with large and relatively clear boundaries (HT and AO). However, the detection of small and narrow organs with diffused boundaries (ES) were challenging. Sophisticated atlas selection and multi-atlas fusion algorithms may further improve the quality of segmentations.

  14. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    Energy Technology Data Exchange (ETDEWEB)

    Garnica-Garza, H M, E-mail: hgarnica@cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Monterrey, Via del Conocimiento 201 Parque de Investigacion e Innovacion Tecnologica, Apodaca NL CP 66600 (Mexico)

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5{sup 0} around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  15. Inverse planned stereotactic intensity modulated radiotherapy (IMRT) in the treatment of incompletely and completely resected adenoid cystic carcinomas of the head and neck: initial clinical results and toxicity of treatment

    International Nuclear Information System (INIS)

    Münter, MW; Schulz-Ertner, D; Hof, H; Nikoghosyan, A; Jensen, A; Nill, S; Huber, P; Debus, J

    2006-01-01

    Presenting the initial clinical results in the treatment of complex shaped adenoid cystic carcinomas (ACC) of the head and neck region by inverse planned stereotactic IMRT. 25 patients with huge ACC in different areas of the head and neck were treated. At the time of radiotherapy two patients already suffered from distant metastases. A complete resection of the tumor was possible in only 4 patients. The remaining patients were incompletely resected (R2: 20; R1: 1). 21 patients received an integrated boost IMRT (IBRT), which allow the use of different single doses for different target volumes in one fraction. All patients were treated after inverse treatment planning and stereotactic target point localization. The mean folllow-up was 22.8 months (91 – 1490 days). According to Kaplan Meier the three year overall survival rate was 72%. 4 patients died caused by a systemic progression of the disease. The three-year recurrence free survival was according to Kaplan Meier in this group of patients 38%. 3 patients developed an in-field recurrence and 3 patient showed a metastasis in an adjacent lymph node of the head and neck region. One patient with an in-field recurrence and a patient with the lymph node recurrence could be re-treated by radiotherapy. Both patients are now controlled. Acute side effects >Grade II did only appear so far in a small number of patients. The inverse planned stereotactic IMRT is feasible in the treatment of ACC. By using IMRT, high control rates and low side effects could by achieved. Further evaluation concerning the long term follow-up is needed. Due to the technical advantage of IMRT this treatment modality should be used if a particle therapy is not available

  16. Planning study to compare dynamic and rapid arc techniques for postprostatectomy radiotherapy of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cambria, R.; Cattani, F.; Pansini, F.; Vigorito, S.; Russo, S. [Istituto Europeo di Oncologia, Department of Medical Physics, Milan (Italy); Jereczek-Fossa, B.A.; Orecchia, R. [Istituto Europeo di Oncologia, Department of Radiation Oncology, Milan (Italy); Universita degli Studi di Milano, Milan (Italy); Ciardo, D.; Zerini, D. [Istituto Europeo di Oncologia, Department of Radiation Oncology, Milan (Italy); Cozzi, L. [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland)

    2014-06-15

    To compare our standard technique for postprostatectomy radiotherapy of prostate cancer, i.e. using two lateral conformal dynamic arcs with volumetric-modulated arc therapy (VMAT) performed with the RapidArc {sup registered} (Varian Medical Systems, Palo Alto, CA, USA). The plans were referred to as DA and RA, respectively. The treatment plans of 44 patients receiving adjuvant/salvage radiotherapy in the first months of 2010 were compared. In all cases, the prescribed total dose was 66-68.2 Gy (2.2 Gy per fraction). Both DA and RA plans were optimized in terms of dose coverage and constraints. Small differences between the techniques were observed for planning target volume (PTV) dose distribution, whereas significant differences in sparing of organs at risk (OARs) were recorded (p < 0.0001). The OAR values (median; 95 % confidence interval, CI) were: rectum: D{sub 30} {sub %} = 60.7 Gy (59.40-62.04 Gy) and 48.2 Gy (46.40-52.72 Gy), D{sub 60} {sub %} = 34.1 Gy (28.50-38.92 Gy) and 27.7 Gy (21.80-31.51 Gy); bladder: D{sub 30} {sub %} = 57.3 Gy (45.83-64.53 Gy) and 46.4 Gy (33.23-61.48 Gy), D{sub 50} {sub %} = 16.4 Gy (11.89-42.38 Gy) and 17.2 Gy (10.97-27.90 Gy), for DA and RA, respectively. Treatment times were very similar, whereas the monitor units (MU) were 550 ± 29 versus 277 ± 3 for RA and DA, respectively. Dose-volume histograms (DVHs) show improvements in OAR sparing with RA. However, the RA technique is associated with almost double the number of MUs compared to DA. Regarding the PTV, DA is slightly superior in terms of D{sub 2} {sub %} and dose homogeneity. On the whole, the results suggest that RA be the favorable technique. (orig.) [German] Vergleich unserer Standardtechnik bei der Strahlentherapie nach Prostatektomie bei Prostatakrebs, ausgefuehrt mit zwei lateral dynamischen Rotationsbestrahlungen, der volumenmodulierten Arc-Therapie (VMAT, DA) und der RapidArc {sup registered} (RA, Varian Medical Systems, Palo Alto, CA, USA). Es wurden die

  17. Implementation of an image guided intensity-modulated protocol for post-prostatectomy radiotherapy: planning data and acute toxicity outcomes.

    Science.gov (United States)

    Chua, Benjamin; Min, Myo; Wood, Maree; Edwards, Sarah; Hoffmann, Matthew; Greenham, Stuart; Kovendy, Andrew; McKay, Michael J; Shakespeare, Thomas P

    2013-08-01

    There is substantial interest in implementation of image-guided intensity-modulated radiotherapy (IG-IMRT) in the post-prostatectomy setting. We describe our implementation of IG-IMRT, and examine how often published organ-at-risk (OAR) constraints were met. Furthermore, we evaluate the incidence of acute genitourinary and gastrointestinal toxicities when patients were treated according to our protocol. Patients were eligible if they received post-prostatectomy radiotherapy (PPRT). Planning data were collected prospectively, and toxicity assessments were collected before, during and after treatment. Seventy-five eligible patients received either 64 Gy (19%) or 66 Gy (81%) in a single phase to the prostate bed. Suggested rectal dose-constraints of V40Gy image guidance. Non-IMRT OAR constraints were met in most cases. IMRT-specific constraints were less often achieved despite margin reductions, suggesting the need for review of guidelines. Severe toxicity was rare, and most patients did not experience deterioration in urinary or bowel function attributable to radiotherapy. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  18. Intensity-Modulated Radiotherapy for Locally Advanced Non-Small-Cell Lung Cancer: A Dose-Escalation Planning Study

    International Nuclear Information System (INIS)

    Lievens, Yolande; Nulens, An; Gaber, Mousa Amr; Defraene, Gilles; De Wever, Walter; Stroobants, Sigrid; Van den Heuvel, Frank

    2011-01-01

    Purpose: To evaluate the potential for dose escalation with intensity-modulated radiotherapy (IMRT) in positron emission tomography-based radiotherapy planning for locally advanced non-small-cell lung cancer (LA-NSCLC). Methods and Materials: For 35 LA-NSCLC patients, three-dimensional conformal radiotherapy and IMRT plans were made to a prescription dose (PD) of 66 Gy in 2-Gy fractions. Dose escalation was performed toward the maximal PD using secondary endpoint constraints for the lung, spinal cord, and heart, with de-escalation according to defined esophageal tolerance. Dose calculation was performed using the Eclipse pencil beam algorithm, and all plans were recalculated using a collapsed cone algorithm. The normal tissue complication probabilities were calculated for the lung (Grade 2 pneumonitis) and esophagus (acute toxicity, grade 2 or greater, and late toxicity). Results: IMRT resulted in statistically significant decreases in the mean lung (p <.0001) and maximal spinal cord (p = .002 and 0005) doses, allowing an average increase in the PD of 8.6-14.2 Gy (p ≤.0001). This advantage was lost after de-escalation within the defined esophageal dose limits. The lung normal tissue complication probabilities were significantly lower for IMRT (p <.0001), even after dose escalation. For esophageal toxicity, IMRT significantly decreased the acute NTCP values at the low dose levels (p = .0009 and p <.0001). After maximal dose escalation, late esophageal tolerance became critical (p <.0001), especially when using IMRT, owing to the parallel increases in the esophageal dose and PD. Conclusion: In LA-NSCLC, IMRT offers the potential to significantly escalate the PD, dependent on the lung and spinal cord tolerance. However, parallel increases in the esophageal dose abolished the advantage, even when using collapsed cone algorithms. This is important to consider in the context of concomitant chemoradiotherapy schedules using IMRT.

  19. Radiotherapy for Hodgkin lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Lena [Rigshospitalet Copenhagen Univ. (Denmark). Depts. of Oncology and Haematology; Yahalom, Joachim (eds.) [Memorial Sloan-Kettering Cancer, New York, NY (United States). Dept. of Radiation Oncology

    2011-07-01

    This book deals in detail with all aspects of the best practice in modern radiotherapy for Hodgkin lymphoma. It provides the background and rationale for the inclusion of radiotherapy in today's combined-modality approach, including special clinical situations such as Hodgkin lymphoma in children, in the pregnant patient, and in the elderly. Radiotherapy planning using state-of-the-art imaging, target definition, planning software, and treatment equipment is expounded in detail. Acute and long-term side effects of radiotherapy are analyzed, and the implications for modern radiotherapy approaches in Hodgkin lymphomas are explained. (orig.)

  20. Radiotherapy for Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Specht, Lena; Yahalom, Joachim

    2011-01-01

    This book deals in detail with all aspects of the best practice in modern radiotherapy for Hodgkin lymphoma. It provides the background and rationale for the inclusion of radiotherapy in today's combined-modality approach, including special clinical situations such as Hodgkin lymphoma in children, in the pregnant patient, and in the elderly. Radiotherapy planning using state-of-the-art imaging, target definition, planning software, and treatment equipment is expounded in detail. Acute and long-term side effects of radiotherapy are analyzed, and the implications for modern radiotherapy approaches in Hodgkin lymphomas are explained. (orig.)

  1. Determining optimal planning target volume and image guidance policy for post-prostatectomy intensity modulated radiotherapy.

    Science.gov (United States)

    Bell, Linda J; Cox, Jennifer; Eade, Thomas; Rinks, Marianne; Herschtal, Alan; Kneebone, Andrew

    2015-07-26

    There is limited information available on the optimal Planning Target Volume (PTV) expansions and image guidance for post-prostatectomy intensity modulated radiotherapy (PP-IMRT). As the prostate bed does not move in a uniform manner, there is a rationale for anisotropic PTV margins with matching to soft tissue. The aim of this study is to find the combination of PTV expansion and image guidance policy for PP-IMRT that provides the best balance of target coverage whilst minimising dose to the organs at risk. The Cone Beam CT (CBCT) images (n = 377) of 40 patients who received PP-IMRT with daily online alignment to bony anatomy (BA) were reviewed. Six different PTV expansions were assessed: 3 published PTV expansions (0.5 cm uniform, 1 cm uniform, and 1 + 0.5 cm posterior) and 3 further anisotropic PTV expansions (Northern Sydney Cancer Centre (NSCC), van Herk, and smaller anisotropic). Each was assessed for size, bladder and rectum coverage and geographic miss. Each CBCT was rematched using a superior soft tissue (SST) and averaged soft tissue (AST) match. Potential geographic miss was assessed using all PTV expansions except the van Herk margin. The 0.5 cm uniform expansion yielded the smallest PTV (median volume = 222.3 cc) and the 1 cm uniform expansion yielded the largest (361.7 cc). The Van Herk expansion includes the largest amount of bladder (28.0 %) and rectum (36.0 %) and the 0.5 cm uniform expansion the smallest (17.1 % bladder; 10.2 % rectum). The van Herk PTV expansion had the least geographic miss with BA matching (4.2 %) and the 0.5 cm uniform margin (28.4 %) the greatest. BA matching resulted in the highest geographic miss rate for all PTVs, followed by SST matching and AST matching. Changing from BA to an AST match decreases potential geographic miss by half to two thirds, depending on the PTV expansion, to image guidance policy for PP-IMRT is daily average soft tissue matching using CBCT scans with a small anisotropic PTV expansion of 0

  2. 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