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Sample records for boost radiotherapy planned

  1. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    SciTech Connect

    Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael; Gebski, Val

    2013-03-15

    A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.

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

    PubMed

    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. PMID:22071169

  3. Volumetric Arc Therapy and Intensity-Modulated Radiotherapy for Primary Prostate Radiotherapy With Simultaneous Integrated Boost to Intraprostatic Lesion With 6 and 18 MV: A Planning Comparison Study

    SciTech Connect

    Ost, Piet; Speleers, Bruno; De Meerleer, Gert; De Neve, Wilfried; Fonteyne, Valerie; Villeirs, Geert; De Gersem, Werner

    2011-03-01

    Purpose: The aim of the present study was to compare intensity-modulated radiotherapy (IMRT) with volumetric arc therapy (VMAT), in the treatment of prostate cancer with maximal dose escalation to the intraprostatic lesion (IPL), without violating the organ-at-risk constraints. Additionally, the use of 6-MV photons was compared with 18-MV photons for all techniques. Methods and Materials: A total of 12 consecutive prostate cancer patients with an IPL on magnetic resonance imaging were selected for the present study. Plans were made for three IMRT field setups (three, five, and seven fields) and one VMAT field setup (single arc). First, optimal plans were created for every technique using biologic and physical planning aims. Next, an additional escalation to the IPL was planned as high as possible without violating the planning aims of the first step. Results: No interaction between the technique and photon energy (p = .928) occurred. No differences were found between the 6- and 18-MV photon beams, except for a reduction in the number of monitor units needed for 18 MV (p < .05). All techniques, except for three-field IMRT, allowed for dose escalation to a median dose of {>=}93 {+-} 6 Gy (mean {+-} standard deviation) to the IPL. VMAT was superior to IMRT for rectal volumes receiving 20-50 Gy (p < .05). Conclusion: VMAT allowed for dose escalation to the IPL with better sparing of the rectum than static three-, five-, and seven-field IMRT setups. High-energy photons had no advantage over low-energy photons.

  4. Planning National Radiotherapy Services

    PubMed Central

    Rosenblatt, Eduardo

    2014-01-01

    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 centers 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 centers, equipment, staff, education programs, quality assurance, and sustainability aspects. Realistic budgetary and cost considerations must also be part of the project proposal or business plan. PMID:25505730

  5. High-dose simultaneously integrated breast boost using intensity-modulated radiotherapy and inverse optimization

    SciTech Connect

    Hurkmans, Coen W. . E-mail: coen.hurkmans@cze.nl; Meijer, Gert J.; Vliet-Vroegindeweij, Corine van; Cassee, Jorien

    2006-11-01

    Purpose: Recently a Phase III randomized trial has started comparing a boost of 16 Gy as part of whole-breast irradiation to a high boost of 26 Gy in young women. Our main aim was to develop an efficient simultaneously integrated boost (SIB) technique for the high-dose arm of the trial. Methods and Materials: Treatment planning was performed for 5 left-sided and 5 right-sided tumors. A tangential field intensity-modulated radiotherapy technique added to a sequentially planned 3-field boost (SEQ) was compared with a simultaneously planned technique (SIB) using inverse optimization. Normalized total dose (NTD)-corrected dose volume histogram parameters were calculated and compared. Results: The intended NTD was produced by 31 fractions of 1.66 Gy to the whole breast and 2.38 Gy to the boost volume. The average volume of the PTV-breast and PTV-boost receiving more than 95% of the prescribed dose was 97% or more for both techniques. Also, the mean lung dose and mean heart dose did not differ much between the techniques, with on average 3.5 Gy and 2.6 Gy for the SEQ and 3.8 Gy and 2.6 Gy for the SIB, respectively. However, the SIB resulted in a significantly more conformal irradiation of the PTV-boost. The volume of the PTV-breast, excluding the PTV-boost, receiving a dose higher than 95% of the boost dose could be reduced considerably using the SIB as compared with the SEQ from 129 cc (range, 48-262 cc) to 58 cc (range, 30-102 cc). Conclusions: A high-dose simultaneously integrated breast boost technique has been developed. The unwanted excessive dose to the breast was significantly reduced.

  6. Three-Dimensional Conformal Simultaneously Integrated Boost Technique for Breast-Conserving Radiotherapy

    SciTech Connect

    Laan, Hans Paul van der

    2007-07-15

    Purpose: To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. Methods and Materials: Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. Results: PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving {>=}107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving {>=}95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. Conclusion: The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity.

  7. Radiotherapy planning using MRI

    NASA Astrophysics Data System (ADS)

    Schmidt, Maria A.; Payne, Geoffrey S.

    2015-11-01

    The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.

  8. Radiotherapy Treatment Planning for Testicular Seminoma

    SciTech Connect

    Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

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

    SciTech Connect

    Turley, Jessica; Claridge Mackonis, Elizabeth

    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.

  10. Benefit of Radiation Boost After Whole-Breast Radiotherapy

    SciTech Connect

    Livi, Lorenzo; Borghesi, Simona; Saieva, Calogero; Fambrini, Massimiliano; Iannalfi, Alberto; Greto, Daniela; Paiar, Fabiola; Scoccianti, Silvia; Simontacchi, Gabriele; Bianchi, Simonetta; Cataliotti, Luigi; Biti, Giampaolo

    2009-11-15

    Purpose: To determine whether a boost to the tumor bed after breast-conserving surgery (BCS) and radiotherapy (RT) to the whole breast affects local control and disease-free survival. Methods and Materials: A total of 1,138 patients with pT1 to pT2 breast cancer underwent adjuvant RT at the University of Florence. We analyzed only patients with a minimum follow-up of 1 year (range, 1-20 years), with negative surgical margins. The median age of the patient population was 52.0 years (+-7.9 years). The breast cancer relapse incidence probability was estimated by the Kaplan-Meier method, and differences between patient subgroups were compared by the log rank test. Cox regression models were used to evaluate the risk of breast cancer relapse. Results: On univariate survival analysis, boost to the tumor bed reduced breast cancer recurrence (p < 0.0001). Age and tamoxifen also significantly reduced breast cancer relapse (p = 0.01 and p = 0.014, respectively). On multivariate analysis, the boost and the medium age (45-60 years) were found to be inversely related to breast cancer relapse (hazard ratio [HR], 0.27; 95% confidence interval [95% CI], 0.14-0.52, and HR 0.61; 95% CI, 0.37-0.99, respectively). The effect of the boost was more evident in younger patients (HR, 0.15 and 95% CI, 0.03-0.66 for patients <45 years of age; and HR, 0.31 and 95% CI, 0.13-0.71 for patients 45-60 years) on multivariate analyses stratified by age, although it was not a significant predictor in women older than 60 years. Conclusion: Our results suggest that boost to the tumor bed reduces breast cancer relapse and is more effective in younger patients.

  11. Excellent Local Control With Stereotactic Radiotherapy Boost After External Beam Radiotherapy in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Hara, Wendy; Loo, Billy W.; Goffinet, Don R.; Chang, Steven D.; Adler, John R.; Pinto, Harlan A.; Fee, Willard E.; Kaplan, Michael J.; Fischbein, Nancy J.; Le, Quynh-Thu

    2008-06-01

    Purpose: To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC). Methods and Materials: Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy. Results: At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors. Conclusion: Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

  12. Tumor Bed Delineation for Partial Breast and Breast Boost Radiotherapy Planned in the Prone Position: What Does MRI Add to X-ray CT Localization of Titanium Clips Placed in the Excision Cavity Wall?

    SciTech Connect

    Kirby, Anna M. Yarnold, John R.; Evans, Philip M.; Morgan, Veronica A.; Schmidt, Maria A.; Scurr, Erica D.; Souza, Nandita de

    2009-07-15

    method of choice for PBI/breast boost radiotherapy planned using tangential fields.

  13. Planning the Breast Boost: Comparison of Three Techniques and Evolution of Tumor Bed During Treatment

    SciTech Connect

    Hepel, Jaroslaw T. Evans, Suzanne B.; Hiatt, Jessica R.; Price, Lori Lyn; DiPetrillo, Thomas; Wazer, David E.; MacAusland, Stephanie G.

    2009-06-01

    Purpose: To evaluate the accuracy of two clinical techniques for electron boost planning compared with computed tomography (CT)-based planning. Additionally, we evaluated the tumor bed characteristics at whole breast planning and boost planning. Methods and Materials: A total of 30 women underwent tumor bed boost planning within 2 weeks of completing whole breast radiotherapy using three planning techniques: scar-based planning, palpation/clinical-based planning, and CT-based planning. The plans were analyzed for dosimetric coverage of the CT-delineated tumor bed. The cavity visualization score was used to define the CT-delineated tumor bed as well or poorly defined. Results: Scar-based planning resulted in inferior tumor bed coverage compared with CT-based planning, with the minimal dose received by 90% of the target volume >90% in 53% and a geographic miss in 53%. The results of palpation/clinical-based planning were significantly better: 87% and 10% for the minimal dose received by 90% of the target volume >90% and geographic miss, respectively. Of the 30 tumor beds, 16 were poorly defined by the cavity visualization score. Of these 16, 8 were well demarcated by the surgical clips. The evaluation of the 22 well-defined tumor beds revealed similar results. A comparison of the tumor bed volume from the initial planning CT scan to the boost planning CT scan revealed a decrease in size in 77% of cases. The mean decrease in volume was 52%. Conclusion: The results of our study have shown that CT-based planning allows for optimal tumor bed coverage compared with clinical and scar-based approaches. However, in the setting of a poorly visualized cavity on CT without surgical clips, palpation/clinical-based planning can help delineate the appropriate target volumes and is superior to scar-based planning. CT simulation at boost planning could allow for a reduction in the boost volumes.

  14. Whole-Brain Radiotherapy With Simultaneous Integrated Boost to Multiple Brain Metastases Using Volumetric Modulated Arc Therapy

    SciTech Connect

    Lagerwaard, Frank J. Hoorn, Elles A.P. van der; Verbakel, Wilko; Haasbeek, Cornelis J.A.; Slotman, Ben J.; Senan, Suresh

    2009-09-01

    Purpose: Volumetric modulated arc therapy (RapidArc [RA]; Varian Medical Systems, Palo Alto, CA) allows for the generation of intensity-modulated dose distributions by use of a single gantry rotation. We used RA to plan and deliver whole-brain radiotherapy (WBRT) with a simultaneous integrated boost in patients with multiple brain metastases. Methods and Materials: Composite RA plans were generated for 8 patients, consisting of WBRT (20 Gy in 5 fractions) with an integrated boost, also 20 Gy in 5 fractions, to Brain metastases, and clinically delivered in 3 patients. Summated gross tumor volumes were 1.0 to 37.5 cm{sup 3}. RA plans were measured in a solid water phantom by use of Gafchromic films (International Specialty Products, Wayne, NJ). Results: Composite RA plans could be generated within 1 hour. Two arcs were needed to deliver the mean of 1,600 monitor units with a mean 'beam-on' time of 180 seconds. RA plans showed excellent coverage of planning target volume for WBRT and planning target volume for the boost, with mean volumes receiving at least 95% of the prescribed dose of 100% and 99.8%, respectively. The mean conformity index was 1.36. Composite plans showed much steeper dose gradients outside Brain metastases than plans with a conventional summation of WBRT and radiosurgery. Comparison of calculated and measured doses showed a mean gamma for double-arc plans of 0.30, and the area with a gamma larger than 1 was 2%. In-room times for clinical RA sessions were approximately 20 minutes for each patient. Conclusions: RA treatment planning and delivery of integrated plans of WBRT and boosts to multiple brain metastases is a rapid and accurate technique that has a higher conformity index than conventional summation of WBRT and radiosurgery boost.

  15. Simultaneous integrated intensity-modulated radiotherapy boost for locally advanced gynecological cancer: Radiobiological and dosimetric considerations

    SciTech Connect

    Guerrero, Mariana; Li, X. Allen . E-mail: ali@radonc.mcw.edu; Ma Lijun; Linder, Jeanette; Deyoung, Chad; Erickson, Beth

    2005-07-01

    Purpose: Whole-pelvis irradiation (WPI) followed by a boost to the tumor site is the standard of practice for the radiotherapeutic management of locally advanced gynecologic cancers. The boost is frequently administered by use of brachytherapy or, occasionally, external-beam radiotherapy (EBRT) when brachytherapy does not provide sufficient coverage because of the size of the tumor or the geometry of the patient. In this work, we propose using an intensity-modulated radiotherapy (IMRT) simultaneous integrated boost (SIB), which is a single-phase process, to replace the conventional two-phase process involving WPI plus a boost. Radiobiological modeling is used to design appropriate regimens for the IMRT SIB. To demonstrate feasibility, a dosimetric study is carried out on an example patient. Methods and Materials: The standard linear-quadratic (LQ) model is used to calculate the biologically effective dose (BED) and equivalent uniform dose (EUD). A series of regimens that are biologically equivalent to those conventional two-phase treatments is calculated for the proposed SIB. A commercial inverse planning system (Corvus) was used to generate IMRT SIB plans for a sample patient case that used the newly designed fractionations. The dose-volume histogram (DVH) and EUD of both the target and normal structures for conventional treatments and the SIB are compared. A sparing factor was introduced to characterize the sparing of normal structures. Results: Fractionation regimes that are equivalent to the conventional treatments and are suitable for the IMRT SIB are deduced. For example, a SIB plan with 25 x 3.1 Gy (77.5 Gy) to a tumor is equivalent to a conventional treatment of EBRT of 45 Gy to the whole pelvis in 25 fractions plus a high-dose rate (HDR) brachytherapy boost with 30 Gy in 5 fractions. The normal tissue BED is found to be lower for the SIB plan than for the whole-pelvis plus HDR scheme when a sparing factor for the critical structures is considered. This

  16. Postmastectomy radiotherapy with integrated scar boost using helical tomotherapy

    SciTech Connect

    Rong Yi; Yadav, Poonam; Welsh, James S.; Fahner, Tasha; Paliwal, Bhudatt

    2012-10-01

    The purpose of this study was to evaluate helical tomotherapy dosimetry in postmastectomy patients undergoing treatment for chest wall and positive nodal regions with simultaneous integrated boost (SIB) in the scar region using strip bolus. Six postmastectomy patients were scanned with a 5-mm-thick strip bolus covering the scar planning target volume (PTV) plus 2-cm margin. For all 6 cases, the chest wall received a total cumulative dose of 49.3-50.4 Gy with daily fraction size of 1.7-2.0 Gy. Total dose to the scar PTV was prescribed to 58.0-60.2 Gy at 2.0-2.5 Gy per fraction. The supraclavicular PTV and mammary nodal PTV received 1.7-1.9 dose per fraction. Two plans (with and without bolus) were generated for all 6 cases. To generate no-bolus plans, strip bolus was contoured and overrode to air density before planning. The setup reproducibility and delivered dose accuracy were evaluated for all 6 cases. Dose-volume histograms were used to evaluate dose-volume coverage of targets and critical structures. We observed reduced air cavities with the strip bolus setup compared with what we normally see with the full bolus. The thermoluminescence dosimeters (TLD) in vivo dosimetry confirmed accurate dose delivery beneath the bolus. The verification plans performed on the first day megavoltage computed tomography (MVCT) image verified that the daily setup and overall dose delivery was within 2% accuracy compared with the planned dose. The hotspot of the scar PTV in no-bolus plans was 111.4% of the prescribed dose averaged over 6 cases compared with 106.6% with strip bolus. With a strip bolus only covering the postmastectomy scar region, we observed increased dose uniformity to the scar PTV, higher setup reproducibility, and accurate dose delivered beneath the bolus. This study demonstrates the feasibility of using a strip bolus over the scar using tomotherapy for SIB dosimetry in postmastectomy treatments.

  17. Ductal Carcinoma in Situ-The Influence of the Radiotherapy Boost on Local Control

    SciTech Connect

    Wong, Philip; Lambert, Christine; Agnihotram, Ramanakumar V.; David, Marc; Duclos, Marie; Freeman, Carolyn R.

    2012-02-01

    Purpose: Local recurrence (LR) of ductal carcinoma in situ (DCIS) is reduced by whole-breast irradiation after breast-conserving surgery (BCS). However, the benefit of adding a radiotherapy boost to the surgical cavity for DCIS is unclear. We sought to determine the impact of the boost on LR in patients with DCIS treated at the McGill University Health Centre. Methods and Materials: A total of 220 consecutive cases of DCIS treated with BCS and radiotherapy between January 2000 and December 2006 were reviewed. Of the patients, 36% received a radiotherapy boost to the surgical cavity. Median follow-up was 46 months for the boost and no-boost groups. Kaplan-Meier survival analyses and Cox regression analyses were performed. Results: Compared with the no-boost group, patients in the boost group more frequently had positive and <0.1-cm margins (48% vs. 8%) (p < 0.0001) and more frequently were in higher-risk categories as defined by the Van Nuys Prognostic (VNP) index (p = 0.006). Despite being at higher risk for LR, none (0/79) of the patients who received a boost experienced LR, whereas 8 of 141 patients who did not receive a boost experienced an in-breast LR (log-rank p = 0.03). Univariate analysis of prognostic factors (age, tumor size, margin status, histological grade, necrosis, and VNP risk category) revealed only the presence of necrosis to significantly correlate with LR (log-rank p = 0.003). The whole-breast irradiation dose and fractionation schedule did not affect LR rate. Conclusions: Our results suggest that the use of a radiotherapy boost improves local control in DCIS and may outweigh the poor prognostic effect of necrosis.

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

    SciTech Connect

    Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond . E-mail: Raymond.Miralbell@hcuge.ch

    2005-05-01

    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

  19. A planning study of simultaneous integrated boost with forward IMRT for multiple brain metastases

    SciTech Connect

    Liang, Xiaodong; Ni, Lingqin; Hu, Wei; Chen, Weijun; Ying, Shenpeng; Gong, Qiangjun; Liu, Yanmei

    2013-07-01

    The objective of this study was to evaluate the dose conformity and feasibility of whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in patients with 1 to 3 brain metastases. Forward intensity-modulated radiation therapy plans were generated for 10 patients with 1 to 3 brain metastases on Pinnacle 6.2 Treatment Planning System. The prescribed dose was 30 Gy to the whole brain (planning target volume [PTV]{sub wbrt}) and 40 Gy to individual brain metastases (PTV{sub boost}) simultaneously, and both doses were given in 10 fractions. The maximum diameters of individual brain metastases ranged from 1.6 to 6 cm, and the summated PTVs per patient ranged from 1.62 to 69.81 cm{sup 3}. Conformity and feasibility were evaluated regarding conformation number and treatment delivery time. One hundred percent volume of the PTV{sub boost} received at least 95% of the prescribed dose in all cases. The maximum doses were less than 110% of the prescribed dose to the PTV{sub boost}, and all of the hot spots were within the PTV{sub boost}. The volume of the PTV{sub wbrt} that received at least 95% of the prescribed dose ranged from 99.2% to 100%. The mean values of conformation number were 0.682. The mean treatment delivery time was 2.79 minutes. Ten beams were used on an average in these plans. Whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in 1 to 3 brain metastases is feasible, and treatment delivery time is short.

  20. Long-Term Results of Targeted Intraoperative Radiotherapy (Targit) Boost During Breast-Conserving Surgery

    SciTech Connect

    Vaidya, Jayant S.; Baum, Michael; Tobias, Jeffrey S.; Wenz, Frederik; Massarut, Samuele; Keshtgar, Mohammed; Hilaris, Basil; Saunders, Christobel; Williams, Norman R.; Brew-Graves, Chris; Corica, Tammy; Roncadin, Mario; Kraus-Tiefenbacher, Uta; Suetterlin, Marc; Bulsara, Max; Joseph, David

    2011-11-15

    Purpose: We have previously shown that delivering targeted radiotherapy to the tumour bed intraoperatively is feasible and desirable. In this study, we report on the feasibility, safety, and long-term efficacy of TARGeted Intraoperative radioTherapy (Targit), using the Intrabeam system. Methods and Materials: A total of 300 cancers in 299 unselected patients underwent breast-conserving surgery and Targit as a boost to the tumor bed. After lumpectomy, a single dose of 20 Gy was delivered intraoperatively. Postoperative external beam whole-breast radiotherapy excluded the usual boost. We also performed a novel individualized case control (ICC) analysis that computed the expected recurrences for the cohort by estimating the risk of recurrence for each patient using their characteristics and follow-up period. Results: The treatment was well tolerated. The median follow up was 60.5 months (range, 10-122 months). Eight patients have had ipsilateral recurrence: 5-year Kaplan Meier estimate for ipsilateral recurrence is 1.73% (SE 0.77), which compares well with that seen in the boosted patients in the European Organization for Research and Treatment of Cancer study (4.3%) and the UK STAndardisation of breast RadioTherapy study (2.8%). In a novel ICC analysis of 242 of the patients, we estimated that there should be 11.4 recurrences; in this group, only 6 recurrences were observed. Conclusions: Lumpectomy and Targit boost combined with external beam radiotherapy results in a low local recurrence rate in a standard risk patient population. Accurate localization and the immediacy of the treatment that has a favorable effect on tumour microenvironment may contribute to this effect. These long-term data establish the long-term safety and efficacy of the Targit technique and generate the hypothesis that Targit boost might be superior to an external beam boost in its efficacy and justifies a randomized trial.

  1. Whole-Field Simultaneous Integrated-Boost Intensity-Modulated Radiotherapy for Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Wong, Frank C.S.; Ng, Alice W.Y.; Lee, Victor H.F.; Lui, Collin M.M.; Yuen, K.-K.; Sze, W.-K.; Leung, T.-W.; Tung, Stewart Y.

    2010-01-15

    Purpose: To retrospectively review the outcomes of our patients with newly diagnosed nondisseminated nasopharyngeal carcinoma treated with intensity-modulated radiotherapy using a whole-field simultaneous integrated-boost technique. Methods and Materials: A total of 175 patients treated with WF-SIB between mid-2004 and 2005 were eligible for study inclusion. The distribution of disease by stage was Stage IA in 10.9%, Stage IIA in 2.3%, Stage IIB in 21.7%, Stage III in 41.1%, Stage IVA in 14.9%, and Stage IVB in 9.1%. Of the 175 patients, 2 (1.2%), 10 (5.7%), and 163 (93.1%) had World Health Organization type I, II, and III histologic features, respectively. We prescribed 70 Gy, 60 Gy, and 54 Gy delivered in 33 fractions within 6.5 weeks at the periphery of three planning target volumes (PTV; PTV70, PTV60, and PTV54, respectively). Of the 175 patients, 46 with early T-stage disease received a brachytherapy boost, and 127 with advanced local or regional disease received chemotherapy. Results: The median follow-up period was 34 months. The overall 3-year local failure-free survival, regional failure-free survival, distant failure-free survival, and overall survival rate was 93.6%, 93.3%, 86.6%, and 87.2%, respectively. Cox regression analysis showed Stage N2-N3 disease (p = .029) and PTV (p = .024) to be independent factors predicting a greater risk of distant failure and poor overall survival, respectively. Grade 3 acute mucositis/pharyngitis occurred in 23.4% of patients, and Stage T4 disease was the only significant predictor of mucositis/pharyngitis (p = .021). Conclusion: Whole-field simultaneous integrated-boost intensity-modulated radiotherapy with a dose >70 Gy achieved excellent locoregional control, without an excess incidence of severe, acute mucositis/pharyngitis, in the present study. Strategies for using such highly conformal treatment for patients with a large tumor and late N-stage disease are potential areas of investigation for future studies.

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

    SciTech Connect

    Vaidya, Jayant S. . E-mail: j.s.vaidya@dundee.ac.uk; 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

    2006-12-01

    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.

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

    PubMed Central

    Richters, Lisa; Fridrich, Claudius; Markiefka, Birgid; Bongartz, Rudolf; Semrau, Robert; Mallmann, Peter; Kraemer, Stefan

    2014-01-01

    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. PMID:25587453

  4. Simultaneous Integrated Boost Intensity-Modulated Radiotherapy in Patients With High-Grade Gliomas

    SciTech Connect

    Cho, Kwan Ho; Kim, Joo-Young; Lee, Seung Hoon

    2010-10-01

    Purpose: We analyzed outcomes of simultaneous integrated boost (SIB) intensity-modulated radiotherapy (IMRT) in patients with high-grade gliomas, compared with a literature review. Methods and Materials: Forty consecutive patients (WHO grade III, 14 patients; grade IV, 26 patients) treated with SIB-IMRT were analyzed. A dose of 2.0 Gy was delivered to the planning target volume with a SIB of 0.4 Gy to the gross tumor volume with a total dose of 60 Gy to the gross tumor volume and 50 Gy to the planning target volume in 25 fractions during 5 weeks. Twenty patients received temozolomide chemotherapy. Results: At a median follow-up of 13.4 months (range, 3.7-55.9 months), median survival was 14.8 months. One- and 2-year survival rates were 78% and 65%, respectively, for patients with grade III tumors and 56% and 31%, respectively, for patients with grade IV tumors. Age ({<=}50 vs. >50), grade (III vs. IV), subtype (astrocytoma vs. oligodendroglioma or mixed), and a Zubrod performance score (0-1 vs. >2) were predictive of survival. Of 25 (63%) patients who had recurrences, 17 patients had local failure, 9 patients had regional failure, and 1 patient had distant metastasis. Toxicities were acceptable. Conclusions: SIB-IMRT with the dose/fractionation used in this study is feasible and safe, with a survival outcome similar to the historical control. The shortening of treatment time by using SIB-IMRT may be of value, although further investigation is warranted to prove its survival advantage.

  5. Incentive pay plans boost managers' performance.

    PubMed

    Biggs, D P

    1987-03-01

    Incentive compensation, which has become commonplace in highly competitive industries, is gradually being introduced in health care settings. Although it has not been used extensively in not-for-profit hospitals, its advantages make it a natural tool for administrators who want to retain their best managers and to achieve important special objectives. Management incentives--awards based on the accomplishment of special objectives--enable boards of trustees and senior managers not only to meet difficult hospital objectives but also to attract and motivate key managers and to promote participative management and teamwork. An effective management incentive compensation program requires five support systems: strategic and operating plans; annual objectives for each manager derived from the strategic and operating plans; measureable performance standards; management action plans, which incorporate the objectives and performance standards and are used in directing each manager's efforts; and a performance evaluation system that forces tough yet reasonable evaluations. In addition to these systems, senior managers must exhibit commitment to change, and objectives must go beyond simply managing individual units well, targeting such goals as improvement of outpatient care utilization, recruitment of specialized staff physicians, and the creation of preferred provider and health maintenance organizations. PMID:10280978

  6. A cosmetic evaluation of breast cancer treatment: A randomized study of radiotherapy boost technique

    SciTech Connect

    Vass, Sylvie . E-mail: sylvie.vass@ssss.gouv.qc.ca; Bairati, Isabelle

    2005-08-01

    Purpose: To compare cosmetic results of two different radiotherapy (RT) boost techniques used in the treatment of breast cancer after whole breast radiotherapy and to identify factors affecting cosmetic outcomes. Methods and Materials: Between 1996 and 1998, 142 patients with Stage I and II breast cancer were treated with breast conservative surgery and adjuvant RT. Patients were then randomly assigned to receive a boost dose of 15 Gy delivered to the tumor bed either by iridium 192, or a combination of photons and electrons. Cosmetic evaluations were done on a 6-month basis, with a final evaluation at 36 months after RT. The evaluations were done using a panel of global and specific subjective scores, a digitized scoring system using the breast retraction assessment (BRA) measurement, and a patient's self-assessment evaluation. As cosmetic results were graded according to severity, the comparison of boost techniques was done using the ordinal logistic regression model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) are presented. Results: At 36 months of follow-up, there was no significant difference between the two groups with respect to the global subjective cosmetic outcome (OR = 1.40; 95%CI = 0.69-2.85, p = 0.35). Good to excellent scores were observed in 65% of implant patients and 62% of photon/electron patients. At 24 months and beyond, telangiectasia was more severe in the implant group with an OR of 9.64 (95%CI = 4.05-22.92, p < 0.0001) at 36 months. The only variable associated with a worse global cosmetic outcome was the presence of concomitant chemotherapy (OR = 3.87; 95%CI = 1.74-8.62). The BRA value once adjusted for age, concomitant chemotherapy, and boost volume showed a positive association with the boost technique. The BRA value was significantly greater in the implant group (p 0.03). There was no difference in the patient's final self-assessment score between the two groups. Three variables were statistically associated with

  7. Phase I/II Trial of Hyperfractionated Concomitant Boost Proton Radiotherapy for Supratentorial Glioblastoma Multiforme

    SciTech Connect

    Mizumoto, Masashi; Tsuboi, Koji; Igaki, Hiroshi; Yamamoto, Tetsuya; Takano, Shingo; Oshiro, Yoshiko; Hayashi, Yasutaka; Hashii, Haruko; Kanemoto, Ayae; Nakayama, Hidetsugu; Sugahara, Shinji; Sakurai, Hideyuki; Matsumura, Akira; Tokuuye, Koichi

    2010-05-01

    Purpose: To evaluate the safety and efficacy of postoperative hyperfractionated concomitant boost proton radiotherapy with nimustine hydrochloride for supratentorial glioblastoma multiforme (GBM). Methods and Materials: Twenty patients with histologically confirmed supratentorial GBM met the following criteria: (1) a Karnofsky performance status of >=60; (2) the diameter of the enhanced area before radiotherapy was <=40 cm; and (3) the enhanced area did not extend to the brain stem, hypothalamus, or thalamus. Magnetic resonance imaging (MRI) T{sub 2}-weighted high area (clinical tumor volume 3 [CTV3]) was treated by x-ray radiotherapy in the morning (50.4 Gy in 28 fractions). More than 6 hours later, 250 MeV proton beams were delivered to the enhanced area plus a 10-mm margin (CTV2) in the first half of the protocol (23.1 GyE in 14 fractions) and to the enhanced volume (CTV1) in the latter half (23.1 GyE in 14 fraction). The total dose to the CTV1 was 96.6 GyE. Nimustine hydrochloride (80 mg/m2) was administered during the first and fourth weeks. Results: Acute toxicity was mainly hematologic and was controllable. Late radiation necrosis and leukoencephalopathy were each seen in one patient. The overall survival rates after 1 and 2 years were 71.1% and 45.3%, respectively. The median survival period was 21.6 months. The 1- and 2-year progression-free survival rates were 45.0% and 15.5%, respectively. The median MRI change-free survival was 11.2 months. Conclusions: Hyperfractionated concomitant boost proton radiotherapy (96.6 GyE in 56 fractions) for GBM was tolerable and beneficial if the target size was well considered. Further studies are warranted to pursue the possibility of controlling border region recurrences.

  8. Radiotherapy Boost for the Dominant Intraprostatic Cancer Lesion-A Systematic Review and Meta-Analysis.

    PubMed

    von Eyben, Finn Edler; Kiljunen, Timo; Kangasmaki, Aki; Kairemo, Kalevi; von Eyben, Rie; Joensuu, Timo

    2016-06-01

    External beam radiotherapy (EBRT) for prostate cancer can be performed with a high dose of 86 Gy; however, one-tenth or more of the patients will develop recurrence. Prostate cancer is mainly multifocal, but a dominant intraprostatic lesion (DIL) is often the site of local recurrence after EBRT. We undertook a systematic review and meta-analysis to clarify whether functional imaging might identify the DIL and whether a RT boost to the DIL might be increased to an ultrahigh dose level of ≥ 90 Gy without increased toxicity. Of 62 selected studies, 13 reported the size of the DIL. The mean of the median DIL volumes was 2.4 cm(3) (95% confidence interval, 0.9-4.4 cm(3)). Eighteen diagnostic studies with 1205 patients evaluated the diagnostic accuracy using multiparametric magnetic resonance imaging for intraprostatic cancer lesions. Evaluating 14,654 prostate segments, the diagnostic accuracy was 77%. Eleven therapeutic studies with 988 patients reported a RT boost for the DIL. The summary boost dose for the DIL was a mean of 89 Gy in 5 studies using intensity modulated RT (calculated as the equivalent dose in 2-Gy fractions) and a mean of 141 Gy in 4 studies using a combination of EBRT and brachytherapy (P = .018, t test). In 1 therapeutic study, 239 patients had a 98% 10-year disease-free survival rate. Many of our therapeutic studies used a boost dose to the DIL of > 90 Gy. The reported boost for DIL is effective and safe. PMID:26768965

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

    SciTech Connect

    Quon, Harvey; Cheung, Patrick C.F.; Loblaw, D. Andrew; Morton, Gerard; Pang, Geordi; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Thomas, Gillian; Kiss, Alex; Mamedov, Alexandre; Deabreu, Andrea

    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

  10. Induction and concurrent chemotherapy with concomitant boost radiotherapy in non-small cell lung cancer.

    PubMed

    Oral, Ethem Nezih; Aydiner, Adnan; Eralp, Yesim; Topuz, Erkan

    2005-01-01

    This study was designed to evaluate the tolerability and therapeutic activity of paclitaxel and carboplatin combination therapy followed by radical thoracic radiotherapy with a concomitant boost technique with concurrent weekly paclitaxel in good performance status of patients with stage IIIA and IIIB non-small cell lung cancer. Patients with newly diagnosed inoperable non-small cell lung cancer received paclitaxel (100 mg/m(2)) as a 1-h infusion on d 1,8,15,28,35, and 42. Carboplatin (area under the curve of 6) was given as a 30-min infusion on d 1 and 28. Radiotherapy commenced on d 49 and was delivered with accelerated fractionation with concomitant boost at 1.8 Gy/fraction/d, 5 d/week and 1.5 Gy/fraction/d to a boost field as a second daily treatment for the last 10 treatment days to 60 Gy/35 fractions/5 wk. During radiation treatment, paclitaxel (60 mg/m(2)) was given as a 1-h infusion once weekly for 5 wk. Twenty-four patients were enrolled in the study. Hematologic toxicities and alopecia were the major acute toxicities during induction chemotherapy; 8.7% of the patients experienced grade 3-4 neutropenia and alopecia. The main acute toxicity of concurrent chemoradiotherapy was esophagitis; grade 3 esophagitis was documented in 23.5% of the patients. No major late toxicity was seen. Overall response rate to the treatment was 65.2%. The median and 1-yr overall-survival rates were 24.9 mo and 63.8%, respectively. The median and 1-yr progression-free survival rates were 9.0 mo and 27.8%, respectively. The main acute toxicities were hematologic toxicity, esophagitis, and alopecia. The response rate and the survival rates achieved with this treatment regimen are particularly noteworthy, especially considering the advanced stage of the patients treated. PMID:16260854

  11. 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

    PubMed Central

    Phak, Jeong Hoon; Kim, Hun Jung; Kim, Woo Chul

    2015-01-01

    Background Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. The purpose of this study was to compare the prostate-specific antigen (PSA) kinetics between conventionally fractionated external beam radiotherapy (CF-EBRT) and SBRT boost after whole pelvis EBRT (WP-EBRT) in localized prostate cancer. Methods A total of 77 patients with localized prostate cancer [T-stage, T1–T3; Gleason score (GS) 5–9; PSA < 20 ng/mL] were enrolled. A total of 35 patients were treated with SBRT boost (21 Gy in 3 fractions) after WP-EBRT and 42 patients were treated with CF-EBRT (45 Gy WP-EBRT and boost of 25.2–30.6 Gy in 1.8-Gy fractions). PSA nadir and rate of change in PSA (slope) were calculated and compared. Results With a median follow-up of 52.4 months (range, 14–74 months), the median PSA nadir and slope for SBRT boost were 0.29 ng/mL and −0.506, −0.235, −0.129, and −0.092 ng/mL/mo, respectively, for durations of 1 year, 2 years, 3 years, and 4 years postradiotherapy. Similarly, for CF-EBRT, the median PSA nadir and slopes were 0.39 ng/mL and −0.720 ng/mL/mo, −0.204 ng/mL/mo, −0.121 ng/mL/mo, and −0.067 ng/mL/mo, respectively. The slope of CF-EBRT was significantly different with a greater median rate of change for 1 year postradiotherapy than that of SBRT boost (P = 0.018). Contrastively, the slopes of SBRT boost for durations of 2 years, 3 years, and 4 years tended to be continuously greater than that of CF-EBRT. The significantly lower PSA nadir was observed in SBRT boost (median nadir 0.29 ng/mL) compared with CF-EBRT (median nadir 0.35 ng/mL, P = 0.025). Five-year biochemical failure (BCF) free survival was 94.3% for SBRT boost and 78.6% for CF-EBRT (P = 0.012). 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

  12. Simultaneous integrated boost to intraprostatic lesions using different energy levels of intensity-modulated radiotherapy and volumetric-arc therapy

    PubMed Central

    Sonmez, S; Erbay, G; Guler, O C; Arslan, G

    2014-01-01

    Objective: This study compared the dosimetry of volumetric-arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) with a dynamic multileaf collimator using the Monte Carlo algorithm in the treatment of prostate cancer with and without simultaneous integrated boost (SIB) at different energy levels. Methods: The data of 15 biopsy-proven prostate cancer patients were evaluated. The prescribed dose was 78 Gy to the planning target volume (PTV78) including the prostate and seminal vesicles and 86 Gy (PTV86) in 39 fractions to the intraprostatic lesion, which was delineated by MRI or MR-spectroscopy. Results: PTV dose homogeneity was better for IMRT than VMAT at all energy levels for both PTV78 and PTV86. Lower rectum doses (V30–V50) were significantly higher with SIB compared with PTV78 plans in both IMRT and VMAT plans at all energy levels. The bladder doses at high dose level (V60–V80) were significantly higher in IMRT plans with SIB at all energy levels compared with PTV78 plans, but no significant difference was observed in VMAT plans. VMAT plans resulted in a significant decrease in the mean monitor units (MUs) for 6, 10, and 15 MV energy levels both in plans with and those without SIB. Conclusion: Dose escalation to intraprostatic lesions with 86 Gy is safe without causing serious increase in organs at risk (OARs) doses. VMAT is advantageous in sparing OARs and requiring less MU than IMRT. Advances in knowledge: VMAT with SIB to intraprostatic lesion is a feasible method in treating prostate cancer. Additionally, no dosimetric advantage of higher energy is observed. PMID:24319009

  13. Planning tools for modulated electron radiotherapy

    SciTech Connect

    Surucu, Murat; Klein, Eric E.; Mamalui-Hunter, Maria; Mansur, David B.; Low, Daniel A.

    2010-05-15

    Purpose: To develop tools to plan modulated electron radiotherapy (MERT) and to compare the MERT plans to conventional or intensity modulated radiotherapy (IMRT) treatment plans. Methods: Monte Carlo dose calculations of electron fields shaped with the inherent photon multileaf collimators (MLCs) were investigated in this study. Treatment plans for four postmastectomy breast cancer patients were generated using MERT. The distances from the patient skin surfaces to the distal planning target volume surfaces were computed along the beam axis direction to determine the physical depth. Electron beam energies were selected to provide target coverage at these depths and energy bins were generated. A custom built MERT treatment planning graphical user interface (MERTgui) was used to shape the electron bins into deliverable electron segments. Monte Carlo dose distribution simulations were performed using the MLC-defined segments generated from the MERTgui. A custom built superposition gui was used to combine doses for each segment using relative weights and final MERT treatment plans were compared to the conventional or IMRT treatment plans. In addition, a demonstration of combined MERT and IMRT treatment plans was performed. Results: The MERT treatment plans provided acceptable target organ coverage in all cases. Relative to 3D conventional or IMRT treatment plans, the MERT plans predicted lower heart doses in all cases; average of the heart D{sub 20} of all plans was reduced from 14.1 to 3.3 Gy. The contralateral breast and contralateral lung doses decreased substantially with MERT planning compared to IMRT (on average, contralateral breast heart D{sub 20} was reduced from 8.7 to 0.7 Gy and contralateral lung D{sub 20} was reduced from 8.4 to 1.2 Gy with MERT). Ipsilateral lung D{sub 20} was lower with MERT than with the conventional plans (44.6 vs 29.2 Gy with MERT), but greater when compared against IMRT treatment plans (25.4 vs 28.9 Gy with MERT). A MERT and IMRT

  14. Dosimetric correlation of acute and late toxicities in high-risk prostate cancer patients treated with three-dimensional conformal radiotherapy followed by intensity modulated radiotherapy boost

    PubMed Central

    Kapoor, Rakesh; Bansal, Anshuma; Kumar, Narendra; Oinam, Arun S.

    2016-01-01

    Introduction: In prostate cancer, higher radiation doses are often related to higher local control rates. However, the clinical effect of these higher doses on normal tissue toxicities is generally overlooked. We dosimetrically analyze sequential intensity modulated radiotherapy (IMRT) plans in high-risk prostate cancer patients and correlate them with acute and late normal tissue toxicities. Materials and Methods: Twenty-five high-risk prostate cancer patients were planned with three-dimensional conformal radiotherapy to a dose of 50 Gy delivered in 25 fractions in 5 weeks, followed by seven-field IMRT boost, to a dose of 24 Gy delivered in 12 fractions in 2.5 weeks, along with hormonal therapy. Acute and late toxicities were analyzed using Radiation Therapy Oncology Group toxicity criteria. Student's t-test was used for correlating doses received by normal tissues with toxicity grade. Five-year disease-free survival (DFS) and biochemical relapse-free survival (RFS) were evaluated using Kaplan–Meier analysis. Results: Median follow-up of patients was 65 months. Of 25 patients, two developed acute Grade 2 rectal toxicity. Only 1 patient developed acute Grade 2 bladder toxicity. Late Grade 2 and 3 rectal toxicity was seen in 2 and 1 patient, respectively. Late Grade 2 and 3 bladder toxicity was seen in 1 patient each. Grade 2 or more acute rectal toxicity correlated significantly with rectal volume receiving >70 Gy (P = 0.04). The 5-year DFS and biochemical RFS was 70.2% and 79.2%, respectively. One patient failed locally and seven failed at distant sites. Conclusion: Sequential IMRT with a dose of 74 Gy and maximum androgen blockade is well tolerated in high-risk patients in Indian setup with adequate control rates. PMID:27555679

  15. Why to start the concomitant boost in accelerated radiotherapy for advanced laryngeal cancer in week 3

    SciTech Connect

    Terhaard, Chris H.J. . E-mail: C.H.J.Terhaard@AZU.nl; Kal, Henk B.; Hordijk, Gerrit-Jan

    2005-05-01

    analysis, besides the fractionation schedule (relative risk [RR], 2.6 for HAS vs. ASO), pretreatment tracheotomy/stridor (RR 4.3, yes vs. no), and local tumor response 3-6 weeks after radiotherapy (RR 5.1, no vs. yes) were independent factors for local control. Tumor control probability analysis indicated that the onset of repopulation may be about 4-6 days earlier for the HAS regimen. The onset of repopulation in the HAS regimen is probably at the end of the second week or at the beginning of the third week. Severe late toxicity was observed in the HAS group and ASO group in, respectively, 11% and 16%. In multivariate analysis this toxicity related significantly to the field size and pretreatment tracheotomy/stridor. Conclusions: In our study the timing of the boost in accelerated radiotherapy for advanced laryngeal cancer was an independent factor for local control, favoring the use of a concomitant boost in Week 3. This finding may indicate that accelerated repopulation of tumor cells starts early in the treatment phase.

  16. Preliminary analysis of the sequential simultaneous integrated boost technique for intensity-modulated radiotherapy for head and neck cancers

    PubMed Central

    Miyazaki, Masayoshi; Nishiyama, Kinji; Ueda, Yoshihiro; Ohira, Shingo; Tsujii, Katsutomo; Isono, Masaru; Masaoka, Akira; Teshima, Teruki

    2016-01-01

    The aim of this study was to compare three strategies for intensity-modulated radiotherapy (IMRT) for 20 head-and-neck cancer patients. For simultaneous integrated boost (SIB), doses were 66 and 54 Gy in 30 fractions for PTVboost and PTVelective, respectively. Two-phase IMRT delivered 50 Gy in 25 fractions to PTVelective in the First Plan, and 20 Gy in 10 fractions to PTVboost in the Second Plan. Sequential SIB (SEQ-SIB) delivered 55 Gy and 50 Gy in 25 fractions, respectively, to PTVboost and PTVelective using SIB in the First Plan and 11 Gy in 5 fractions to PTVboost in the Second Plan. Conformity indexes (CIs) (mean ± SD) for PTVboost and PTVelective were 1.09 ± 0.05 and 1.34 ± 0.12 for SIB, 1.39 ± 0.14 and 1.80 ± 0.28 for two-phase IMRT, and 1.14 ± 0.07 and 1.60 ± 0.18 for SEQ-SIB, respectively. CI was significantly highest for two-phase IMRT. Maximum doses (Dmax) to the spinal cord were 42.1 ± 1.5 Gy for SIB, 43.9 ± 1.0 Gy for two-phase IMRT and 40.3 ± 1.8 Gy for SEQ-SIB. Brainstem Dmax were 50.1 ± 2.2 Gy for SIB, 50.5 ± 4.6 Gy for two-phase IMRT and 47.4 ± 3.6 Gy for SEQ-SIB. Spinal cord Dmax for the three techniques was significantly different, and brainstem Dmax was significantly lower for SEQ-SIB. The compromised conformity of two-phase IMRT can result in higher doses to organs at risk (OARs). Lower OAR doses in SEQ-SIB made SEQ-SIB an alternative to SIB, which applies unconventional doses per fraction. PMID:26983983

  17. Dose masking feature for BNCT radiotherapy planning

    DOEpatents

    Cook, Jeremy L.; Wessol, Daniel E.; Wheeler, Floyd J.

    2000-01-01

    A system for displaying an accurate model of isodoses to be used in radiotherapy so that appropriate planning can be performed prior to actual treatment on a patient. The nature of the simulation of the radiotherapy planning for BNCT and Fast Neutron Therapy, etc., requires that the doses be computed in the entire volume. The "entire volume" includes the patient and beam geometries as well as the air spaces in between. Isodoses derived from the computed doses will therefore extend into the air regions between the patient and beam geometries and thus depict the unrealistic possibility that radiation deposition occurs in regions containing no physical media. This problem is solved by computing the doses for the entire geometry and then masking the physical and air regions along with the isodose contours superimposed over the patient image at the corresponding plane. The user is thus able to mask out (remove) the contour lines from the unwanted areas of the image by selecting the appropriate contour masking region from the raster image.

  18. Stereotactic Body Radiotherapy as Monotherapy or Post-External Beam Radiotherapy Boost for Prostate Cancer: Technique, Early Toxicity, and PSA Response

    SciTech Connect

    Jabbari, Siavash; Weinberg, Vivian K.; Kaprealian, Tania; Hsu, I-Chow; Ma Lijun; Chuang, Cynthia; Descovich, Martina; Shiao, Stephen; Shinohara, Katsuto; Roach, Mack; Gottschalk, Alexander R.

    2012-01-01

    Purpose: High dose rate (HDR) brachytherapy has been established as an excellent monotherapy or after external-beam radiotherapy (EBRT) boost treatment for prostate cancer (PCa). Recently, dosimetric studies have demonstrated the potential for achieving similar dosimetry with stereotactic body radiotherapy (SBRT) compared with HDR brachytherapy. Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation. Patients and Methods: To date, 38 patients have been treated with SBRT at University of California-San Francisco with a minimum follow-up of 12 months. Twenty of 38 patients were treated with SBRT monotherapy (9.5 Gy Multiplication-Sign 4 fractions), and 18 were treated with SBRT boost (9.5 Gy Multiplication-Sign 2 fractions) post-EBRT and androgen deprivation therapy. PSA nadir to date for 44 HDR brachytherapy boost patients with disease characteristics similar to the SBRT boost cohort was also analyzed as a descriptive comparison. Results: SBRT was well tolerated. With a median follow-up of 18.3 months (range, 12.6-43.5), 42% and 11% of patients had acute Grade 2 gastrourinary and gastrointestinal toxicity, respectively, with no Grade 3 or higher acute toxicity to date. Two patients experienced late Grade 3 GU toxicity. All patients are without evidence of biochemical or clinical progression to date, and favorably low PSA nadirs have been observed with a current median PSA nadir of 0.35 ng/mL (range, <0.01-2.1) for all patients (0.47 ng/mL, range, 0.2-2.1 for the monotherapy cohort; 0.10 ng/mL, range, 0.01-0.5 for the boost cohort). With a median follow-up of 48.6 months (range, 16.4-87.8), the comparable HDR brachytherapy boost cohort has achieved a median PSA nadir of 0.09 ng/mL (range, 0.0-3.3). Conclusions: Early results with SBRT monotherapy and post-EBRT boost for PCa demonstrate acceptable PSA response and minimal toxicity. PSA nadir with SBRT boost

  19. Magnetic Resonance Imaging in Postprostatectomy Radiotherapy Planning

    SciTech Connect

    Sefrova, Jana; Odrazka, Karel; Paluska, Petr; Belobradek, Zdenek; Brodak, Milos; Dolezel, Martin; Prosvic, Petr; Macingova, Zuzana; Vosmik, Milan; Hoffmann, Petr; Louda, Miroslav; Nejedla, Anna

    2012-02-01

    Purpose: To investigate whether the use of magnetic resonance imaging (MRI) in prostate bed treatment planning could influence definition of the clinical target volume (CTV) and organs at risk. Methods and Materials: A total of 21 consecutive patients referred for prostate bed radiotherapy were included in the present retrospective study. The CTV was delineated according to the European Organization for Research and Treatment of Cancer recommendations on computed tomography (CT) and T{sub 1}-weighted (T{sub 1}w) and T{sub 2}-weighted (T{sub 2}w) MRI. The CTV magnitude, agreement, and spatial differences were evaluated on the planning CT scan after registration with the MRI scans. Results: The CTV was significantly reduced on the T{sub 1}w and T{sub 2}w MRI scans (13% and 9%, respectively) compared with the CT scans. The urinary bladder was drawn smaller on the CT scans and the rectum was smaller on the MRI scans. On T{sub 1}w MRI, the rectum and urinary bladder were delineated larger than on T{sub 2}w MRI. Minimal agreement was observed between the CT and T{sub 2}w images. The main spatial differences were measured in the superior and superolateral directions in which the CTV on the MRI scans was 1.8-2.9 mm smaller. In the posterior and inferior border, no difference was seen between the CT and T{sub 1}w MRI scans. On the T{sub 2}w MRI scans, the CTV was larger in these directions (by 1.3 and 1.7 mm, respectively). Conclusions: The use of MRI in postprostatectomy radiotherapy planning resulted in a reduction of the CTV. The main differences were found in the superior part of the prostate bed. We believe T{sub 2}w MRI enables more precise definition of prostate bed CTV than conventional planning CT.

  20. Automated radiotherapy treatment plan integrity verification

    SciTech Connect

    Yang Deshan; Moore, Kevin L.

    2012-03-15

    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.

  1. Dosimetry audit of radiotherapy treatment planning systems.

    PubMed

    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. PMID:25848119

  2. Proton Radiotherapy for Liver Tumors: Dosimetric Advantages Over Photon Plans

    SciTech Connect

    Wang Xiaochun Krishnan, Sunil; Zhang Xiaodong; Dong Lei; Briere, Tina; Crane, Christopher H.; Martel, Mary; Gillin, Michael; Mohan, Radhe; Beddar, Sam

    2008-01-01

    The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V{sub 30}) and the mean liver dose. The stomach and duodenal V{sub 45} were significantly lower with the use of proton radiotherapy. The V{sub 40} and V{sub 50} of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.

  3. 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

    SciTech Connect

    Clavel, Sebastien; Nguyen, David H.A.; Fortin, Bernard; Despres, Philippe; Khaouam, Nader; Donath, David; Soulieres, Denis; Guertin, Louis; Nguyen-Tan, Phuc Felix

    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.

  4. Optimization approaches for planning external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Gozbasi, Halil Ozan

    Cancer begins when cells grow out of control as a result of damage to their DNA. These abnormal cells can invade healthy tissue and form tumors in various parts of the body. Chemotherapy, immunotherapy, surgery and radiotherapy are the most common treatment methods for cancer. According to American Cancer Society about half of the cancer patients receive a form of radiation therapy at some stage. External beam radiotherapy is delivered from outside the body and aimed at cancer cells to damage their DNA making them unable to divide and reproduce. The beams travel through the body and may damage nearby healthy tissue unless carefully planned. Therefore, the goal of treatment plan optimization is to find the best system parameters to deliver sufficient dose to target structures while avoiding damage to healthy tissue. This thesis investigates optimization approaches for two external beam radiation therapy techniques: Intensity-Modulated Radiation Therapy (IMRT) and Volumetric-Modulated Arc Therapy (VMAT). We develop automated treatment planning technology for IMRT that produces several high-quality treatment plans satisfying provided clinical requirements in a single invocation and without human guidance. A novel bi-criteria scoring based beam selection algorithm is part of the planning system and produces better plans compared to those produced using a well-known scoring-based algorithm. Our algorithm is very efficient and finds the beam configuration at least ten times faster than an exact integer programming approach. Solution times range from 2 minutes to 15 minutes which is clinically acceptable. With certain cancers, especially lung cancer, a patient's anatomy changes during treatment. These anatomical changes need to be considered in treatment planning. Fortunately, recent advances in imaging technology can provide multiple images of the treatment region taken at different points of the breathing cycle, and deformable image registration algorithms can

  5. Contribution of FDOPA PET to radiotherapy planning for advanced glioma

    NASA Astrophysics Data System (ADS)

    Dowson, Nicholas; Fay, Michael; Thomas, Paul; Jeffree, Rosalind; McDowall, Robert; Winter, Craig; Coulthard, Alan; Smith, Jye; Gal, Yaniv; Bourgeat, Pierrick; Salvado, Olivier; Crozier, Stuart; Rose, Stephen

    2014-03-01

    Despite radical treatment with surgery, radiotherapy and chemotherapy, advanced gliomas recur within months. Geographic misses in radiotherapy planning may play a role in this seemingly ineluctable recurrence. Planning is typically performed on post-contrast MRIs, which are known to underreport tumour volume relative to FDOPA PET scans. FDOPA PET fused with contrast enhanced MRI has demonstrated greater sensitivity and specificity than MRI alone. One sign of potential misses would be differences between gross target volumes (GTVs) defined using MRI alone and when fused with PET. This work examined whether such a discrepancy may occur. Materials and Methods: For six patients, a 75 minute PET scan using 3,4-dihydroxy-6-18F-fluoro-L-phynel-alanine (18F-FDOPA) was taken within 2 days of gadolinium enhanced MRI scans. In addition to standard radiotherapy planning by an experienced radiotherapy oncologist, a second gross target volume (GTV) was defined by an experienced nuclear medicine specialist for fused PET and MRI, while blinded to the radiotherapy plans. The volumes from standard radiotherapy planning were compared to the PET defined GTV. Results: The comparison indicated radiotherapy planning would change in several cases if FDOPA PET data was available. PET-defined contours were external to 95% prescribed dose for several patients. However, due to the radiotherapy margins, the discrepancies were relatively small in size and all received a dose of 50 Gray or more. Conclusions: Given the limited size of the discrepancies it is uncertain that geographic misses played a major role in patient outcome. Even so, the existence of discrepancies indicates that FDOPA PET could assist in better defining margins when planning radiotherapy for advanced glioma, which could be important for highly conformal radiotherapy plans.

  6. Comparison of intensity-modulated radiotherapy with three-dimensional conformal radiation therapy planning for glioblastoma multiforme

    SciTech Connect

    Chan, Maria F.; Schupak, Karen; Burman, Chandra; Chui, C.-S.; Ling, C. Clifton

    2003-12-31

    This study was designed to assess the feasibility and potential benefit of using intensity-modulated radiotherapy (IMRT) planning for patients newly diagnosed with glioblastoma multiforme (GBM). Five consecutive patients with confirmed histopathologically GBM were entered into the study. These patients were planned and treated with 3-dimensional conformal radiation therapy (3DCRT) using our standard plan of 3 noncoplanar wedged fields. They were then replanned with the IMRT method that included a simultaneous boost to the gross tumor volume (GTV). The dose distributions and dose-volume histograms (DHVs) for the planning treatment volume (PTV), GTV, and the relevant critical structures, as obtained with 3DCRT and IMRT, respectively, were compared. In both the 3DCRT and IMRT plans, 59.4 Gy was delivered to the GTV plus a margin of 2.5 cm, with doses to critical structures below the tolerance threshold. However, with the simultaneous boost in IMRT, a higher tumor dose of {approx}70 Gy could be delivered to the GTV, while still maintaining the uninvolved brain at dose levels of the 3DCRT technique. In addition, our experience indicated that IMRT planning is less labor intensive and time consuming than 3DCRT planning. Our study shows that IMRT planning is feasible and efficient for radiotherapy of GBM. In particular, IMRT can deliver a simultaneous boost to the GTV while better sparing the normal brain and other critical structures.

  7. Conformal radiotherapy, reduced boost volume, hyperfractionated radiotherapy, and online quality control in standard-risk medulloblastoma without chemotherapy: Results of the French M-SFOP 98 protocol

    SciTech Connect

    Carrie, Christian . E-mail: carrie@lyon.fnclcc.fr; Muracciole, Xavier; Gomez, Frederic

    2005-11-01

    Purpose: Between December 1998 and October 2001, patients <19 years old were treated for standard-risk medulloblastoma according to the Medulloblastome-Societe Francaise d'Oncologie Pediatrique 1998 (M-SFOP 98) protocol. Patients received hyperfractionated radiotherapy (36 Gy in 36 fractions) to the craniospinal axis, a boost with conformal therapy restricted to the tumor bed (to a total dose of 68 Gy in 68 fractions), and no chemotherapy. Records of craniospinal irradiation were reviewed before treatment start. Results: A total of 48 patients were considered assessable. With a median follow-up of 45.7 months, the overall survival and progression-free survival rate at 3 years was 89% and 81%, respectively. Fourteen major deviations were detected and eight were corrected. No relapses occurred in the frontal region and none occurred in the posterior fossa outside the boost volume. Nine patients were available for volume calculation without reduction of the volume irradiated. We observed a reduction in the subtentorial volume irradiated to >60 Gy, but a slight increase in the volume irradiated to 40 Gy. No decrease in intelligence was observed in the 22 children tested during the first 2 years. Conclusion: This hyperfractionated radiotherapy protocol with a reduced boost volume and without chemotherapy was not associated with early relapses in children. Moreover, intellectual function seemed to be preserved. These results are promising.

  8. Poster — Thur Eve — 66: Robustness Assessment of a Novel IMRT Planning Method for Lung Radiotherapy

    SciTech Connect

    Ahanj, M.; Bissonnette, J.-P.; Heath, E.; McCann, C.

    2014-08-15

    Conventional radiotherapy treatment planning for lung cancer accounts for tumour motion by increasing the beam apertures. We recently developed an IMRT planning strategy which uses reduced beam apertures in combination with an edge enhancing boost of 110% of the prescription dose to the volume that corresponds to the portion of the CTV that moves outside of the reduced beam. Previous results showed that this approach ensures target coverage while reducing lung dose. In the current study, we evaluate the robustness of this boost volume approach to changes in respiratory motion, including amplitude and phase weight variations. ITV and boost volume plans were generated for 5 NSCLC patients with respiratory motion amplitudes ranging from 1 to 2 cm. A standard 5mm PTV margin was used for all plans. The ORBIT treatment planning tool was used to plan and accumulate dose over 10 respiratory phases defined by the 4DCT datasets. For the phase weight variation study, dose was accumulated for three scenarios: equally-weighted-phases, higher weight assigned to exhale phases and higher weight assigned to inhale phases. For the amplitude variation study, a numerical phantom was used to generate 4DCT datasets corresponding to 7 mm, 10 mm and 14 mm motion amplitudes. Preliminary results found that delivered plans for all phase weight scenarios were clinically acceptable. When normalized to mean lung dose, the boost volume plan delivered 5% more dose to the CTV which indicates the potential for dose escalation using this approach.

  9. Pictorial review. Magnetic resonance for radiotherapy management and treatment planning in prostatic carcinoma.

    PubMed

    Lim, Christopher; Malone, Shawn C; Avruch, Leonard; Breau, Rodney H; Flood, Trevor A; Lim, Megan; Morash, Christopher; Quon, Jeff S; Walsh, Cynthia; Schieda, Nicola

    2015-10-01

    MRI has an important role for radiotherapy (RT) treatment planning in prostate cancer (PCa) providing accurate visualization of the dominant intraprostatic lesion (DIL) and locoregional anatomy, assessment of local staging and depiction of implanted devices. MRI enables the radiation oncologist to optimize RT planning by better defining target tumour volumes (thereby increasing local tumour control), as well as decreasing morbidity (by minimizing the dose to adjacent normal structures). Using MRI, radiation oncologists can define the DIL for delivery of boost doses of RT using a variety of techniques including: stereotactic body radiotherapy, intensity-modulated radiotherapy, proton RT or brachytherapy to improve tumour control. Radiologists require a familiarity with the different RT methods used to treat PCa, as well as an understanding of the advantages and disadvantages of the various MR pulse sequences available for RT planning in order to provide an optimal multidisciplinary RT treatment approach to PCa. Understanding the expected post-RT appearance of the prostate and typical characteristics of local tumour recurrence is also important because MRI is rapidly becoming an integral component for diagnosis, image-guided histological sampling and treatment planning in the setting of biochemical failure after RT or surgery. PMID:26279086

  10. Geometrical pre-planning for conformal radiotherapy.

    PubMed

    Tsougos, Ioannis; Schreibmann, Eduard; Lahanas, Michael; Theodorou, Kiki; Kappas, Constantin; Baltas, Dimos

    2007-01-01

    The optimum selection of beams and arcs in conformal techniques is of the outmost importance in modern radiotherapy. In this work we give a description of an analytic method to aid optimum selection, which is based on minimizing the intersection between beams and organs at risk (OAR) and on minimizing the intersection between the beam and the planning target volume (PTV). An arc-selection function that permits selection of irradiation arcs based on individual beam feasibility is introduce. The method simulates the treatment process by defining a computed beam feasibility, for every possible set of gantry-table angles, by taking into account accurately computer intersection volumes between the OAR and beams. The beams are shaped to conform the target using realistic parameters for the treatment process. The results are displayed on a virtual sphere centred at the isocenter with color-coded regions indicating beam feasibility. Arcs selections are performed by searching the map for successive gantry positions at a certain table angle, with feasibility values greater than a user-specified threshold. The accuracy of the method was confirmed by using geometrical regular shapes, as well as real clinical cases. PMID:17851850

  11. A methodology for boost-glide transport technology planning

    NASA Technical Reports Server (NTRS)

    Repic, E. M.; Olson, G. A.; Milliken, R. J.

    1974-01-01

    A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system.

  12. Effects of Respiratory Motion and Risk-Region Misclassification on Subvolume Boosting in Radiotherapy

    NASA Astrophysics Data System (ADS)

    Ellis, Andrew G.

    Functional imaging advancements have revealed that for many tumors, ideal treatment consists of a non-uniform dose prescription based on tumor subvolume radioresistance characteristics. This treatment has been proven beneficial in planning studies, but puts significant emphasis on accurate subvolume segmentation. Respiratory motion during imaging and treatment compounds this issue in thoracic tumors. This work aimed to assess these target definition challenges using an in-house designed and constructed programmable motion phantom. An FDG loaded PET target simulating distinct risk-regions was driven by twenty breathing patterns of varying shape and motion amplitude. PET and CT images were acquired for each unique motion scenario. There was a direct relationship between autocontoured subvolumes and respiratory motion amplitude, though it was poorly correlated on an individual patient basis due to limited data. Gated PET reconstruction has been shown previously to improve motion affected single-target autocontouring accuracy. This is useful to utilize standard risk-region autocontour thresholds in motion affected anatomy. In this work, gated PET subvolume images effectively eliminated motion artifacts, enabling use of static target threshold guided autocontour thresholds. Spatial location accuracy of all PET autocontoured subvolumes, however, was poor. The high-risk subvolume was particularly misclassified, due to its size (1cc) leading to partial volume effect susceptibility. Clinically, additional tumor heterogeneity information for qualification of the PET defined risk-regions is rarely available. To assess the effects of risk-region misclassification on non-uniform radiotherapy, stereotactic body radiotherapy (SBRT) treatment plans were created targeting the misclassified subvolumes. The resulting DVH analysis showed suboptimal high dose in the true low-risk subvolumes, significantly underdosed high-risk subvolumes, and consistent underdose to the low

  13. Whole brain radiotherapy plus simultaneous in-field boost with image guided intensity-modulated radiotherapy for brain metastases of non-small cell lung cancer

    PubMed Central

    2014-01-01

    Background Whole brain radiotherapy (WBRT) plus sequential focal radiation boost is a commonly used therapeutic strategy for patients with brain metastases. However, recent reports on WBRT plus simultaneous in-field boost (SIB) also showed promising outcomes. The objective of present study is to retrospectively evaluate the efficacy and toxicities of WBRT plus SIB with image guided intensity-modulated radiotherapy (IG-IMRT) for inoperable brain metastases of NSCLC. Methods Twenty-nine NSCLC patients with 87 inoperable brain metastases were included in this retrospective study. All patients received WBRT at a dose of 40 Gy/20 f, and SIB boost with IG-IMRT at a dose of 20 Gy/5 f concurrent with WBRT in the fourth week. Prior to each fraction of IG-IMRT boost, on-line positioning verification and correction were used to ensure that the set-up errors were within 2 mm by cone beam computed tomography in all patients. Results The one-year intracranial control rate, local brain failure rate, and distant brain failure rate were 62.9%, 13.8%, and 19.2%, respectively. The two-year intracranial control rate, local brain failure rate, and distant brain failure rate were 42.5%, 30.9%, and 36.4%, respectively. Both median intracranial progression-free survival and median survival were 10 months. Six-month, one-year, and two-year survival rates were 65.5%, 41.4%, and 13.8%, corresponding to 62.1%, 41.4%, and 10.3% of intracranial progression-free survival rates. Patients with Score Index for Radiosurgery in Brain Metastases (SIR) >5, number of intracranial lesions <3, and history of EGFR-TKI treatment had better survival. Three lesions (3.45%) demonstrated radiation necrosis after radiotherapy. Grades 2 and 3 cognitive impairment with grade 2 radiation leukoencephalopathy were observed in 4 (13.8%) and 4 (13.8%) patients. No dosimetric parameters were found to be associated with these late toxicities. Patients received EGFR-TKI treatment had higher incidence of grades 2–3

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

    PubMed Central

    Kim, Hun Jung; Phak, Jung Hoon; Kim, Woo Chul

    2015-01-01

    Purpose Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate-specific antigen (PSA) kinetics after SBRT has not been well characterized. The purpose of the current study is to assess the kinetics of PSA for low- and intermediate-risk prostate cancer patients treated with SBRT using Cyberknife as both monotherapy and boost after whole pelvic radiotherapy (WPRT) in the absence of androgen deprivation therapy. Methods A total of 61 patients with low- and intermediated-risk prostate cancer treated with SBRT as monotherapy (36.25 Gy in 5 fractions in 32 patients) and SBRT (21 Gy in 3 fractions in 29 patients) boost combined with WPRT (45 Gy in 25 fractions). Patients were excluded if they failed therapy by the Phoenix definition or had androgen deprivation therapy. PSA nadir and rate of change in PSA over time (slope) were calculated and compared. Results With a median follow-up of 52.4 months (range, 14–74 months), for SBRT monotherapy, the median PSA nadir was 0.31 ng/mL (range, 0.04–1.15 ng/mL) and slopes were –0.41 ng/mL/mo, –0.17 ng/mL/mo, –0.12 ng/mL/mo, and –0.09 ng/mL/mo, respectively, for durations of 1 year, 2 years, 3 years, and 4 years postradiotherapy. Similarly, for SBRT boost after WPRT, the median PSA nadir was 0.34 ng/mL (range, 0.04–1.44 ng/mL) and slopes were –0.53 ng/mL/mo, –0.25 ng/mL/mo, –0.14 ng/mL/mo, and –0.09 ng/mL/mo, respectively. The median nadir and slopes of SBRT monotherapy did not differ significantly from those of SBRT boost after WPRT. Benign PSA bounces were common in 30.4% of all cohorts, and the median time to PSA bounce was 12 months (range, 6–25 months). 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

  15. Hypofractionated Accelerated Radiotherapy Using Concomitant Intensity-Modulated Radiotherapy Boost Technique for Localized High-Risk Prostate Cancer: Acute Toxicity Results

    SciTech Connect

    Lim, Tee S.; Cheung, Patrick Loblaw, D. Andrew; Morton, Gerard; Sixel, Katharina E.; Pang, Geordi; Basran, Parminder; Zhang Liying; Tirona, Romeo; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Thomas, Gillian

    2008-09-01

    Purpose: To evaluate the acute toxicities of hypofractionated accelerated radiotherapy (RT) using a concomitant intensity-modulated RT boost in conjunction with elective pelvic nodal irradiation for high-risk prostate cancer. Methods and Materials: This report focused on 66 patients entered into this prospective Phase I study. The eligible patients had clinically localized prostate cancer with at least one of the following high-risk features (Stage T3, Gleason score {>=}8, or prostate-specific antigen level >20 ng/mL). Patients were treated with 45 Gy in 25 fractions to the pelvic lymph nodes using a conventional four-field technique. A concomitant intensity-modulated radiotherapy boost of 22.5 Gy in 25 fractions was delivered to the prostate. Thus, the prostate received 67.5 Gy in 25 fractions within 5 weeks. Next, the patients underwent 3 years of adjuvant androgen ablative therapy. Acute toxicities were assessed using the Common Terminology Criteria for Adverse Events, version 3.0, weekly during treatment and at 3 months after RT. Results: The median patient age was 71 years. The median pretreatment prostate-specific antigen level and Gleason score was 18.7 ng/L and 8, respectively. Grade 1-2 genitourinary and gastrointestinal toxicities were common during RT but most had settled at 3 months after treatment. Only 5 patients had acute Grade 3 genitourinary toxicity, in the form of urinary incontinence (n = 1), urinary frequency/urgency (n = 3), and urinary retention (n = 1). None of the patients developed Grade 3 or greater gastrointestinal or Grade 4 or greater genitourinary toxicity. Conclusion: The results of the present study have indicated that hypofractionated accelerated RT with a concomitant intensity-modulated RT boost and pelvic nodal irradiation is feasible with acceptable acute toxicity.

  16. Radiotherapy cost-calculation and its impact on capacity planning.

    PubMed

    Lievens, Yolande; Slotman, Berend Jan

    2003-08-01

    The rapid rise in health care expenses has resulted in an increased interest in the cost of treatments from a cost-effectiveness point of view for management purposes and in a reimbursement setting. The economics of radiotherapy within the global context of health care, and more specifically of cancer therapy, are discussed in this review. Furthermore, the calculation of radiotherapy costs from an institutional perspective using activity-based costing and on capacity planning in radiotherapy - at the departmental as well as at the national level - by integrating cost, epidemiological and scientifico-technological data are focused on. PMID:19807460

  17. Boost your bargaining clout in contract negotiations with Medicare managed care plans.

    PubMed

    1999-06-01

    Boost your clout in negotiations with Medicare plans. Find out what Desert Physicians Association in Mesa, AZ, has learned in its dispute over reimbursement rates with CIGNA, and get some advice from a Medicare managed care consultant on how to negotiate contracts with Medicare plans. PMID:10538679

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

    SciTech Connect

    Wong, William W.; Schild, Steven E.; Vora, Sujay A.; Ezzell, Gary A.; Nguyen, Ba D.; Ram, Panol C.; Roarke, Michael C.

    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.

  19. Radiotherapy Treatment Plans With RapidArc for Prostate Cancer Involving Seminal Vesicles and Lymph Nodes

    SciTech Connect

    Yoo, Sua; Wu, Q. Jackie; Lee, W. Robert; Yin Fangfang

    2010-03-01

    Purpose: Dosimetric results and treatment delivery efficiency of RapidArc plans to those of conventional intensity-modulated radiotherapy (IMRT) plans were compared using the Eclipse treatment planning system for high-risk prostate cancer. Materials and Methods: This study included 10 patients. The primary planning target volume (PTV{sub P}) contained prostate, seminal vesicles, and pelvic lymph nodes with a margin. The boost PTV (PTV{sub B}) contained prostate and seminal vesicles with a margin. The total prescription dose was 75.6 Gy (46.8 Gy to PTV{sub P} and an additional 28.8 Gy to PTV{sub B}; 1.8 Gy/fraction). Three plans were generated for each PTV: Multiple-field IMRT, one-arc RapidArc (1ARC), and two-arc RapidArc (2ARC). Results: In the primary IMRT with PTV{sub P}, average mean doses to bladder, rectum and small bowel were lower by 5.9%, 7.7% and 4.3%, respectively, than in the primary 1ARC and by 3.6%, 4.8% and 3.1%, respectively, than in the primary 2ARC. In the boost IMRT with PTV{sub B}, average mean doses to bladder and rectum were lower by 2.6% and 4.8% than with the boost 1ARC and were higher by 0.6% and 0.2% than with the boost 2ARC. Integral doses were 7% to 9% higher with RapidArc than with IMRT for both primary and boost plans. Treatment delivery time was reduced by 2-7 minutes using RapidArc. Conclusion: For PTVs including prostate, seminal vesicles, and lymph nodes, IMRT performed better in dose sparing for bladder, rectum, and small bowel than did RapidArc. For PTVs including prostate and seminal vesicles, RapidArc with two arcs provided plans comparable to those for IMRT. The treatment delivery is more efficient with RapidArc.

  20. Long-term toxicity of an intraoperative radiotherapy boost using low energy X-rays during breast-conserving surgery

    SciTech Connect

    Kraus-Tiefenbacher, Uta . E-mail: uta.kraus-tiefenbacher@radonk.ma.uni-heidelberg.de; Bauer, Lelia; Scheda, Antonella; Fleckenstein, Katharina; Keller, Anke; Herskind, Carsten; Steil, Volker; Melchert, Frank; Wenz, Frederik

    2006-10-01

    Purpose: Intraoperative radiotherapy (IORT) as a boost for breast cancer delivers a high single dose of radiation to a late-reacting tissue; therefore late toxicity is of particular interest, and long-term follow-up is warranted. To date there are only limited data available on breast cancer patients treated with IORT using low energy X-rays. We analyzed toxicity and cosmesis after IORT as a boost with a minimum follow-up of 18 months. Methods and Materials: A total of 73 patients treated with IORT (20 Gy/50 kV X-rays; INTRABEAM [Carl Zeiss Surgical, Oberkochen, Germany]) to the tumor bed during breast-conserving surgery as a boost followed by whole-breast radiotherapy (WBRT, 46 Gy) underwent a prospective, predefined follow-up (median, 25 months; range 18-44 months), including clinical examination and breast ultrasound at 6-months and mammographies at 1-year intervals. Toxicities were documented using the common toxicity criteria (CTC)/European Organization for Research and Treatment of Cancer and the LENT-SOMA score. Cosmesis was evaluated with a score from 1 to 4. Results: The IORT in combination with WBRT was well tolerated, with no Grade 3 or 4 skin toxicities and no telangiectasias. Fibrosis of the entire breast was observed in 5% of the patients. A circumscribed fibrosis around the tumor bed was palpable in up to 27% with a peak around 18 months after therapy and a decline thereafter. The observed toxicitiy rates were not influenced by age, tumor stage, or systemic therapy. The cosmetic outcome was good to excellent in {>=}90% of cases. Conclusions: After IORT of the breast using low-energy X-rays, no unexpected toxicity rates were observed during long-term-follow-up.

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

    SciTech Connect

    Hardee, Matthew E.; Raza, Shahzad; Becker, Stewart J.; Jozsef, Gabor; Lymberis, Stella C.; Hochman, Tsivia; Goldberg, Judith D.; DeWyngaert, Keith J.; Formenti, Silvia C.

    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 but

  2. Intensity-Modulated Radiotherapy as Primary Therapy for Prostate Cancer: Report on Acute Toxicity After Dose Escalation With Simultaneous Integrated Boost to Intraprostatic Lesion

    SciTech Connect

    Fonteyne, Valerie Villeirs, Geert; Speleers, Bruno; Neve, Wilfried de; Wagter, Carlos de; Lumen, Nicolas; Meerleer, Gert de

    2008-11-01

    Purpose: To report on the acute toxicity of a third escalation level using intensity-modulated radiotherapy for prostate cancer (PCa) and the acute toxicity resulting from delivery of a simultaneous integrated boost (SIB) to an intraprostatic lesion (IPL) detected on magnetic resonance imaging (MRI), with or without spectroscopy. Methods and Materials: Between January 2002 and March 2007, we treated 230 patients with intensity-modulated radiotherapy to a third escalation level as primary therapy for prostate cancer. If an IPL (defined by MRI or MRI plus spectroscopy) was present, a SIB was delivered to the IPL. To report on acute toxicity, patients were seen weekly during treatment and 1 and 3 months after treatment. Toxicity was scored using the Radiation Therapy Oncology Group toxicity scale, supplemented by an in-house-developed scoring system. Results: The median dose to the planning target volume was 78 Gy. An IPL was found in 118 patients. The median dose to the MRI-detected IPL and MRI plus spectroscopy-detected IPL was 81 Gy and 82 Gy, respectively. No Grade 3 or 4 acute gastrointestinal toxicity developed. Grade 2 acute gastrointestinal toxicity was present in 26 patients (11%). Grade 3 genitourinary toxicity was present in 15 patients (7%), and 95 patients developed Grade 2 acute genitourinary toxicity (41%). No statistically significant increase was found in Grade 2-3 acute gastrointestinal or genitourinary toxicity after a SIB to an IPL. Conclusion: The results of our study have shown that treatment-induced acute toxicity remains low when intensity-modulated radiotherapy to 80 Gy as primary therapy for prostate cancer is used. In addition, a SIB to an IPL did not increase the severity or incidence of acute toxicity.

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

    SciTech Connect

    Su, M; 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.

  4. Quality of Life After Hypofractionated Concomitant Intensity-Modulated Radiotherapy Boost for High-Risk Prostate Cancer

    SciTech Connect

    Quon, Harvey; Cheung, Patrick C.F.; Loblaw, D. Andrew; Morton, Gerard; Pang, Geordi; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Kiss, Alex; Mamedov, Alexandre; Deabreu, Andrea

    2012-06-01

    Purpose: To evaluate the change in health-related quality of life (QOL) of patients with high-risk prostate cancer treated using hypofractionated radiotherapy combined with long-term androgen deprivation therapy. Methods and Materials: A prospective Phase I-II study enrolled patients with any of the following: clinical Stage T3 disease, prostate-specific antigen level {>=}20 ng/mL, or Gleason score 8-10. Radiotherapy consisted of 45 Gy (1.8 Gy per fraction) to the pelvic lymph nodes with a concomitant 22.5 Gy intensity-modulated radiotherapy boost to the prostate, for a total of 67.5 Gy (2.7 Gy per fraction) in 25 fractions over 5 weeks. Daily image guidance was performed using three gold seed fiducials. Quality of life was measured using the Expanded Prostate Cancer Index Composite (EPIC), a validated tool that assesses four primary domains (urinary, bowel, sexual, and hormonal). Results: From 2004 to 2007, 97 patients were treated. Median follow-up was 39 months. Compared with baseline, at 24 months there was no statistically significant change in the mean urinary domain score (p = 0.99), whereas there were decreases in the bowel (p < 0.01), sexual (p < 0.01), and hormonal (p < 0.01) domains. The proportion of patients reporting a clinically significant difference in EPIC urinary, bowel, sexual, and hormonal scores at 24 months was 27%, 31%, 55%, and 60%, respectively. However, moderate and severe distress related to these symptoms was minimal, with increases of only 3% and 5% in the urinary and bowel domains, respectively. Conclusions: Hypofractionated radiotherapy combined with long-term androgen deprivation therapy was well tolerated. Although there were modest rates of clinically significant patient-reported urinary and bowel toxicity, most of this caused only mild distress, and moderate and severe effects on QOL were limited. Additional follow-up is ongoing to characterize long-term QOL.

  5. A phase II trial of accelerated radiotherapy using weekly stereotactic conformal boost for supratentorial glioblastoma multiforme: RTOG 0023

    SciTech Connect

    Cardinale, Robert; Choucair, Ali; Gillin, Michael; Chakravarti, Arnab; Schultz, Christopher; Souhami, Luis; Chen, Allan; Pham, Huong; Mehta, Minesh

    2006-08-01

    Purpose: This phase II trial was performed to assess the feasibility, toxicity, and efficacy of dose-intense accelerated radiation therapy using weekly fractionated stereotactic radiotherapy (FSRT) boost for patients with glioblastoma multiforme (GBM). Methods and Materials: Patients with histologically confirmed GBM with postoperative enhancing tumor plus tumor cavity diameter <60 mm were enrolled. A 50-Gy dose of standard radiation therapy (RT) was given in daily 2-Gy fractions. In addition, patients received four FSRT treatments, once weekly, during Weeks 3 to 6. FSRT dosing of either 5 Gy or 7 Gy per fraction was given for a cumulative dose of 70 or 78 Gy in 29 (25 standard RT + 4 FSRT) treatments over 6 weeks. After the RT course, carmustine (BCNU) at 80 mg/m{sup 2} was given for 3 days, every 8 weeks, for 6 cycles. Results: A total of 76 patients were analyzed. Toxicity included: 3 Grade 4 chemotherapy, 3 acute Grade 4 radiotherapy, and 1 Grade 3 late. The median survival time was 12.5 months. No survival difference is seen when compared with the RTOG historical database. Patients with gross total resection (41%) had a median survival time of 16.6 months vs. 12.0 months for historic controls with gross total resection (p = 0.14). Conclusion: This first, multi-institutional FSRT boost trial for GBM was feasible and well tolerated. There is no significant survival benefit using this dose-intense RT regimen. Subset analysis revealed a trend toward improved outcome for GTR patients suggesting that patients with minimal disease burden may benefit from this form of accelerated RT.

  6. 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

    SciTech Connect

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

    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.

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

    SciTech Connect

    Chengqiang, L; Yin, Y; Chen, L

    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.

  8. Sacred Heart University's Online Emergency Plan Boosts Interagency Cooperation

    ERIC Educational Resources Information Center

    Healy, Paul J.

    2010-01-01

    Taking its responsibility to students, faculty, and staff seriously, Sacred Heart University wanted a highly effective emergency response plan, one that could be updated at any time, with information always available to first responders and other authorized users. For this lifesaving function, the university built a Web site based on Microsoft[R]…

  9. Bayesian network models for error detection in radiotherapy plans

    NASA Astrophysics Data System (ADS)

    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.

  10. Bayesian network models for error detection in radiotherapy plans.

    PubMed

    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. PMID:25768885

  11. Newer positron emission tomography radiopharmaceuticals for radiotherapy planning: an overview

    PubMed Central

    Mukherjee, Anirban

    2016-01-01

    Positron emission tomography-computed tomography (PET-CT) has changed cancer imaging in the last decade, for better. It can be employed for radiation treatment planning of different cancers with improved accuracy and outcomes as compared to conventional imaging methods. 18F-fluorodeoxyglucose remains the most widely used though relatively non-specific cancer imaging PET tracer. A wide array of newer PET radiopharmaceuticals has been developed for targeted imaging of different cancers. PET-CT with such new PET radiopharmaceuticals has also been used for radiotherapy planning with encouraging results. In the present review we have briefly outlined the role of PET-CT with newer radiopharmaceuticals for radiotherapy planning and briefly reviewed the available literature in this regard. PMID:26904575

  12. Aluminium projects boost New South Wales power plans

    SciTech Connect

    Scott, W.E.

    1980-11-01

    New South Wales is expanding its power-generating capacity to power new aluminum smelters and extensions to existing smelting facilities planned for the 1980s. Cheap coal-based electricity is vital to the program's success. Officials deny reports that other consumers will suffer power shortages during the development stages and are confident the State's energy policies to provide 7400 MW of new capacity and introduce 500-kV transmission will also supply new industry and community power needs. Only France has a comparable power expansion program. (DCK)

  13. Toxicity Assessment of Pelvic Intensity-Modulated Radiotherapy With Hypofractionated Simultaneous Integrated Boost to Prostate for Intermediate- and High-Risk Prostate Cancer

    SciTech Connect

    McCammon, Robert; Rusthoven, Kyle E.; Kavanagh, Brian; Newell, Sherri B.S.; Newman, Francis M.S.; Raben, David

    2009-10-01

    Purpose: To evaluate the toxicity of pelvic intensity-modulated radiotherapy (IMRT) with hypofractionated simultaneous integrated boost (SIB) to the prostate for patients with intermediate- to high-risk prostate cancer. Methods and Materials: A retrospective toxicity analysis was performed in 30 consecutive patients treated definitively with pelvic SIB-IMRT, all of whom also received androgen suppression. The IMRT plans were designed to deliver 70 Gy in 28 fractions (2.5 Gy/fraction) to the prostate while simultaneously delivering 50.4 Gy in 28 fractions (1.8 Gy/fraction) to the pelvic lymph nodes. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to score toxicity. Results: The most common acute Grade 2 events were cystitis (36.7%) and urinary frequency/urgency (26.7%). At a median follow-up of 24 months, late toxicity exceeding Grade 2 in severity was uncommon, with two Grade 3 events and one Grade 4 event. Grade 2 or greater acute bowel toxicity was associated with signficantly greater bowel volume receiving {>=}25 Gy (p = .04); Grade 2 or greater late bowel toxicity was associated with a higher bowel maximal dose (p = .04) and volume receiving {>=}50 Gy (p = .02). Acute or late bladder and rectal toxicity did not correlate with any of the dosimetric parameters examined. Conclusion: Pelvic IMRT with SIB to the prostate was well tolerated in this series, with low rates of Grade 3 or greater acute and late toxicity. SIB-IMRT combines pelvic radiotherapy and hypofractionation to the primary site and offers an accelerated approach to treating intermediate- to high-risk disease. Additional follow-up is necessary to fully define the long-term toxicity after hypofractionated, whole pelvic treatment combined with androgen suppression.

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

    SciTech Connect

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

    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.

  15. Approximating convex Pareto surfaces in multiobjective radiotherapy planning

    SciTech Connect

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

    2006-09-15

    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.

  16. Instant-mix whole brain photon with neutron boost radiotherapy for malignant gliomas

    SciTech Connect

    Kolker, J.D.; Halpern, H.J.; Krishnasamy, S.; Brown, F.; Dohrmann, G.; Ferguson, L.; Hekmatpanah, J.; Mullan, J.; Wollman, R.; Blough, R. )

    1990-08-01

    From July 1985 through March 1987, 44 consecutive patients with supratentorial, nonmetastatic anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with whole brain photon irradiation with concomitant neutron boost at the University of Chicago. All patients had biopsy proven disease and surgery ranged from biopsy to total gross excision. Whole brain photon radiation was given at 1.5 Gy per fraction, 5 days weekly for a total dose of 45 Gy in 6 weeks. Neutron boost radiation was prescribed to a target minimum dose that included the pre-surgical CT tumor volume plus 1 cm margin. Neutrons were administered 5-20 minutes prior to photon radiation twice weekly and a total dose of 5.2 Gyn gamma was administered over 6 weeks. Median follow-up was 36 months. The median survival was 40.3 months for anaplastic astrocytoma (10 patients) and 11 months for glioblastoma multiforme (34 patients) and 12 months for the overall group. Variables that predicted longer median survival included histology (AA vs. GBM), age (less than or equal to 39 years vs. older), and extent of surgery (total gross or partial excision vs. biopsy) whereas tumor size and Karnofsky performance status did not have a significant influence. The median survival of the anaplastic astrocytoma group was better than expected compared to the RTOG 80-07 study (a dose-finding study of similar design to this study) and historical data. Reasons for this are discussed.

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

    DOEpatents

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Automatic liver contouring for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    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

  20. Automatic liver contouring for radiotherapy treatment planning.

    PubMed

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

    2015-10-01

    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

  1. Whole Brain Radiotherapy With Hippocampal Avoidance and Simultaneous Integrated Boost for 1-3 Brain Metastases: A Feasibility Study Using Volumetric Modulated Arc Therapy

    SciTech Connect

    Hsu, Fred; Carolan, Hannah; Nichol, Alan; Cao, Fred; Nuraney, Nimet; Lee, Richard; Gete, Ermias; Wong, Frances; Schmuland, Moira; Heran, Manraj; Otto, Karl

    2010-04-15

    Purpose: To evaluate the feasibility of using volumetric modulated arc therapy (VMAT) to deliver whole brain radiotherapy (WBRT) with hippocampal avoidance and a simultaneous integrated boost (SIB) for one to three brain metastases. Methods and Materials: Ten patients previously treated with stereotactic radiosurgery for one to three brain metastases underwent repeat planning using VMAT. The whole brain prescription dose was 32.25 Gy in 15 fractions, and SIB doses to brain metastases were 63 Gy to lesions >=2.0 cm and 70.8 Gy to lesions <2.0 cm in diameter. The mean dose to the hippocampus was kept at <6 Gy{sub 2}. Plans were optimized for conformity and target coverage while minimizing hippocampal and ocular doses. Plans were evaluated on target coverage, prescription isodose to target volume ratio, conformity number, homogeneity index, and maximum dose to prescription dose ratio. Results: Ten patients had 18 metastases. Mean values for the brain metastases were as follows: conformity number = 0.73 +- 0.10, target coverage = 0.98 +- 0.01, prescription isodose to target volume = 1.34 +- 0.19, maximum dose to prescription dose ratio = 1.09 +- 0.02, and homogeneity index = 0.07 +- 0.02. For the whole brain, the mean target coverage and homogeneity index were 0.960 +- 0.002 and 0.39 +- 0.06, respectively. The mean hippocampal dose was 5.23 +- 0.39 Gy{sub 2}. The mean treatment delivery time was 3.6 min (range, 3.3-4.1 min). Conclusions: VMAT was able to achieve adequate whole brain coverage with conformal hippocampal avoidance and radiosurgical quality dose distributions for one to three brain metastases. The mean delivery time was under 4 min.

  2. Electron Density Calibration for Radiotherapy Treatment Planning

    SciTech Connect

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

    2006-09-08

    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 ({rho}e) 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 {rho}e 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.

  3. Electron Density Calibration for Radiotherapy Treatment Planning

    NASA Astrophysics Data System (ADS)

    Herrera-Martínez, F.; Rodríguez-Villafuerte, M.; Martínez-Dávalos, A.; Ruiz-Trejo, C.; Celis-López, M. A.; Lárraga-Gutiérrez, J. M.; García-Garduño, A.

    2006-09-01

    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.

  4. Functional and molecular image guidance in radiotherapy treatment planning optimization.

    PubMed

    Das, Shiva K; Ten Haken, Randall K

    2011-04-01

    Functional and molecular imaging techniques are increasingly being developed and used to quantitatively map the spatial distribution of parameters, such as metabolism, proliferation, hypoxia, perfusion, and ventilation, onto anatomically imaged normal organs and tumor. In radiotherapy optimization, these imaging modalities offer the promise of increased dose sparing to high-functioning subregions of normal organs or dose escalation to selected subregions of the tumor as well as the potential to adapt radiotherapy to functional changes that occur during the course of treatment. The practical use of functional/molecular imaging in radiotherapy optimization must take into cautious consideration several factors whose influences are still not clearly quantified or well understood including patient positioning differences between the planning computed tomography and functional/molecular imaging sessions, image reconstruction parameters and techniques, image registration, target/normal organ functional segmentation, the relationship governing the dose escalation/sparing warranted by the functional/molecular image intensity map, and radiotherapy-induced changes in the image intensity map over the course of treatment. The clinical benefit of functional/molecular image guidance in the form of improved local control or decreased normal organ toxicity has yet to be shown and awaits prospective clinical trials addressing this issue. PMID:21356479

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed Central

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

    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 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 seconds. 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

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

    SciTech Connect

    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.

  8. Optimized radiotherapy treatment planning using the Complication Probability Factor (CPF)

    SciTech Connect

    Wolbarst, A.B.; Sternick, E.S.; Curran, B.H.; Dritschilo, A.

    1980-06-01

    A major obstacle to effective computerized optimization of radiotherapy treatment planning has been the lack of a biologically meaningful and clinically useful objective function. Our approach employs a Complication Probability Factor (CPF) based directly on radiobiological principles and clinical data. The CPF measures the likelihood that a given dose distribution will lead to serious complications in the patient as a result of damage to healthy tissue. A computerized search can be made for a treatment plan which delivers an acceptable tumoricidal dose, yet minimizes the CPF as averaged over the total volume of healthy tissue irradiated. The program is run on a PDP 11/55 in conjunction with a commercial treatment planning package.

  9. The role of PET/CT scanning in radiotherapy planning.

    PubMed

    Jarritt, P H; Carson, K J; Hounsell, A R; Visvikis, D

    2006-09-01

    The introduction of functional data into the radiotherapy treatment planning process is currently the focus of significant commercial, technical, scientific and clinical development. The potential of such data from positron emission tomography (PET) was recognized at an early stage and was integrated into the radiotherapy treatment planning process through the use of image fusion software. The combination of PET and CT in a single system (PET/CT) to form an inherently fused anatomical and functional dataset has provided an imaging modality which could be used as the prime tool in the delineation of tumour volumes and the preparation of patient treatment plans, especially when integrated with virtual simulation. PET imaging typically using 18F-Fluorodeoxyglucose (18F-FDG) can provide data on metabolically active tumour volumes. These functional data have the potential to modify treatment volumes and to guide treatment delivery to cells with particular metabolic characteristics. This paper reviews the current status of the integration of PET and PET/CT data into the radiotherapy treatment process. Consideration is given to the requirements of PET/CT data acquisition with reference to patient positioning aids and the limitations imposed by the PET/CT system. It also reviews the approaches being taken to the definition of functional/tumour volumes and the mechanisms available to measure and include physiological motion into the imaging process. The use of PET data must be based upon a clear understanding of the interpretation and limitations of the functional signal. Protocols for the implementation of this development remain to be defined, and outcomes data based upon clinical trials are still awaited. PMID:16980683

  10. Breast-Conserving Therapy: Radiotherapy Margins for Breast Tumor Bed Boost

    SciTech Connect

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

    2008-11-01

    Purpose: 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. Methods and Materials: A total of 20 patients were studied who had been treated in the supine position for 28 daily fractions. Cone-beam computed tomography scans were regularly acquired according to a shrinking action level setup correction protocol based on bony anatomy registration of the ribs and sternum. The position of the excision area was retrospectively analyzed by gray value cone-beam computed tomography-to-computed tomography registration. Subsequently, three setup correction strategies (on-line, off-line, and no corrections) were applied, according to the rib and breast surface registrations, to estimate the residual setup errors (systematic [{sigma}] and random [{sigma}]) of the excision area. The required margins were calculated using a margin recipe. Results: The image quality of the cone-beam computed tomography scans was sufficient for localization of the EC. The margins required for the investigated setup correction protocols and the setup errors for the left-right, craniocaudal and anteroposterior directions were 8.3 mm ({sigma} = 3.0, {sigma} = 2.6), 10.6 mm ({sigma} = 3.8, {sigma} = 3.2), and 7.7 mm ({sigma} = 2.7, {sigma} = 2.9) for the no correction strategy; 5.6 mm ({sigma} = 2.0, {sigma} = 1.8), 6.5 mm ({sigma} = 2.3, {sigma} = 2.3), and 4.5 mm ({sigma} = 1.5, {sigma} = 1.9) for the on-line rib strategy; and 5.1 mm ({sigma} = 1.8, {sigma} = 1.7), 4.8 mm ({sigma} = 1.7, {sigma} = 1.6), and 3.3 mm ({sigma} = 1.1, {sigma} = 1.6) for the on-line surface strategy, respectively. Conclusion: Considerable geometric uncertainties in the position of the EC relative to the bony anatomy and breast surface have been observed. By using registration of the breast

  11. Phase I Trial of Preoperative Hypofractionated Intensity-Modulated Radiotherapy with Incorporated Boost and Oral Capecitabine in Locally Advanced Rectal Cancer

    SciTech Connect

    Freedman, Gary M. . E-mail: G_Freedman@FCCC.edu; Meropol, Neal J.; Sigurdson, Elin R.; Hoffman, John; Callahan, Elaine; Price, Robert; Cheng, Jonathan; Cohen, Steve; Lewis, Nancy; Watkins-Bruner, Deborah; Rogatko, Andre; Konski, Andre

    2007-04-01

    Purpose: To determine the safety and efficacy of preoperative hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) and an incorporated boost with concurrent capecitabine in patients with locally advanced rectal cancer. Methods and Materials: The eligibility criteria included adenocarcinoma of the rectum, T3-T4 and/or N1-N2 disease, performance status 0 or 1, and age {>=}18 years. Photon IMRT and an incorporated boost were used to treat the whole pelvis to 45 Gy and the gross tumor volume plus 2 cm to 55 Gy in 25 treatments within 5 weeks. The study was designed to escalate the dose to the gross tumor volume in 5-Gy increments in 3-patient cohorts. Capecitabine was given orally 825 mg/m{sup 2} twice daily for 7 days each week during RT. The primary endpoint was the maximal tolerated radiation dose, and the secondary endpoints were the pathologic response and quality of life. Results: Eight patients completed RT at the initial dose level of 55 Gy. The study was discontinued because of toxicity-six Grade 3 toxicities occurred in 3 (38%) of 8 patients. All patients went on to definitive surgical resection, and no patient had a pathologically complete response. Conclusion: This regimen, using hypofractionated RT with an incorporated boost, had unacceptable toxicity despite using standard doses of capecitabine and IMRT. Additional research is needed to determine whether IMRT is able to reduce the side effects during and after pelvic RT with conventional dose fractionation.

  12. Planning With Intensity-Modulated Radiotherapy and Tomotherapy to Modulate Dose Across Breast to Reflect Recurrence Risk (IMPORT High Trial)

    SciTech Connect

    Donovan, Ellen M.; Ciurlionis, Laura; Fairfoul, Jamie; James, Hayley; Mayles, Helen; Manktelow, Sophie; Raj, Sanjay; Tsang, Yat; Tywman, Nicola; Yarnold, John; Coles, Charlotte

    2011-03-15

    Purpose: To establish planning solutions for a concomitant three-level radiation dose distribution to the breast using linear accelerator- or tomotherapy-based intensity-modulated radiotherapy (IMRT), for the U.K. Intensity Modulated and Partial Organ (IMPORT) High trial. Methods and Materials: Computed tomography data sets for 9 patients undergoing breast conservation surgery with implanted tumor bed gold markers were used to prepare three-level dose distributions encompassing the whole breast (36 Gy), partial breast (40 Gy), and tumor bed boost (48 or 53 Gy) treated concomitantly in 15 fractions within 3 weeks. Forward and inverse planned IMRT and tomotherapy were investigated as solutions. A standard electron field was compared with a photon field arrangement encompassing the tumor bed boost volume. The out-of-field doses were measured for all methods. Results: Dose-volume constraints of volume >90% receiving 32.4 Gy and volume >95% receiving 50.4 Gy for the whole breast and tumor bed were achieved. The constraint of volume >90% receiving 36 Gy for the partial breast was fulfilled in the inverse IMRT and tomotherapy plans and in 7 of 9 cases of a forward planned IMRT distribution. An electron boost to the tumor bed was inadequate in 8 of 9 cases. The IMRT methods delivered a greater whole body dose than the standard breast tangents. A contralateral lung volume >2.5 Gy was increased in the inverse IMRT and tomotherapy plans, although it did not exceed the constraint. Conclusion: We have demonstrated a set of widely applicable solutions that fulfilled the stringent clinical trial requirements for the delivery of a concomitant three-level dose distribution to the breast.

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

    SciTech Connect

    Al-Mamgani, Abrahim; Tans, Lisa; Teguh, David N.; Rooij, Peter van; Zwijnenburg, Ellen M.; Levendag, Peter C.

    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.

  14. A Monte Carlo dose calculation tool for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, J. S.; Pawlicki, T.; Jiang, S. B.; Deng, J.; Lee, M. C.; Koumrian, T.; Luxton, M.; Brain, S.

    2002-05-01

    A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ.

  15. Delivery validation of an automated modulated electron radiotherapy plan

    SciTech Connect

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

    2014-06-15

    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.

  16. Hypofractionated Boost to the Dominant Tumor Region With Intensity Modulated Stereotactic Radiotherapy for Prostate Cancer: A Sequential Dose Escalation Pilot Study

    SciTech Connect

    Miralbell, Raymond; Molla, Meritxell; Rouzaud, Michel; Hidalgo, Alberto; Toscas, Jose Ignacio; Lozano, Joan; Sanz, Sergi B.Sc.; Ares, Carmen; Jorcano, Sandra; Linero, Dolors; Escude, Lluis

    2010-09-01

    Purpose: 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. Methods and Materials: After conventional fractionated external radiotherapy to 64 to 64.4Gy, 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 60cc of air was used for internal organ immobilization. Five, 8, and 8 patients were sequentially treated with two fractions of 5, 6, or 7Gy, respectively (normalized total dose in 2Gy/fraction [NTD{sub 2Gy}] < 100Gy, low-dose group), whereas 29 patients received two fractions of 8Gy each (NTD{sub 2Gy} > 100Gy, 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. Results: Two patients presented with Grade 3 acute urinary toxicity. The 5-year probabilities of {>=}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. Conclusion: 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.

  17. Intraoperative Radiotherapy as a Boost During Breast-Conserving Surgery Using Low-Kilovoltage X-Rays: The First 5 Years of Experience With a Novel Approach

    SciTech Connect

    Wenz, Frederik; Welzel, Grit; Blank, Elena; Hermann, Brigitte; Steil, Volker; Suetterlin, Marc; Kraus-Tiefenbacher, Uta

    2010-08-01

    Purpose: Intraoperative radiotherapy (IORT) during breast-conserving surgery (BCS) has been recently introduced using different devices. We report the first 5 years of a single-center experience after introduction of a novel approach to deliver IORT as a tumor bed boost during BCS for breast cancer. Methods and Materials: A total of 155 breast cancers in 154 women (median age, 63 years; range, 30-83 years; T1/T2 = 100/55; N0/N+ = 108/47) were treated between February 2002 and December 2007 at the University Medical Center Mannheim, in whom IORT as tumor bed boost was applied using 50-kV X-rays (20 Gy) followed by 46-50 Gy whole-breast external-beam radiotherapy (EBRT). Chemotherapy, if indicated, was given before EBRT. The median interval between BCS plus IORT and EBRT was 40 days. Median follow-up was 34 months (maximum 80 months, 1 patient lost to follow-up). Overall survival and local relapse-free survival were calculated at 5 years using the Kaplan-Meier method. Seventy-nine patients were evaluated at 3-year follow-up for late toxicity according to the Late Effects in Normal Tissues-Subjective, Objective, Management, and Analytic system. Results: Ten patients died, 2 had in-breast relapse, and 8 developed distant metastases (5-year overall survival = 87.0%; 5-year local relapse-free survival = 98.5%). Grade 3 fibroses of the tumor bed were detected in 5% of the patients after 3 years. Skin toxicity was mild (telangiectases and hyperpigmentations in approximately 6% each). Conclusions: Intraoperative radiotherapy as a tumor bed boost during BCS for breast cancer using low-kilovoltage X-rays followed by EBRT yields low recurrence and toxicity rates.

  18. Development of Advanced Multi-Modality Radiation Treatment Planning Software for Neutron Radiotherapy and Beyond

    SciTech Connect

    Nigg, D; Wessol, D; Wemple, C; Harkin, G; Hartmann-Siantar, C

    2002-08-20

    The Idaho National Engineering and Environmental Laboratory (INEEL) has long been active in development of advanced Monte-Carlo based computational dosimetry and treatment planning methods and software for advanced radiotherapy, with a particular focus on Neutron Capture Therapy (NCT) and, to a somewhat lesser extent, Fast-Neutron Therapy. The most recent INEEL software system of this type is known as SERA, Simulation Environment for Radiotherapy Applications. As a logical next step in the development of modern radiotherapy planning tools to support the most advanced research, INEEL and Lawrence Livermore National Laboratory (LLNL), the developers of the PEREGRTNE computational engine for radiotherapy treatment planning applications, have recently launched a new project to collaborate in the development of a ''next-generation'' multi-modality treatment planning software system that will be useful for all modern forms of radiotherapy.

  19. Radiotherapy.

    PubMed

    Adamietz, Irenaus A

    2010-01-01

    The intrathoracic growth of the tumor causes several severe symptoms as cough, dyspnea, chest pain, hemoptysis, hoarseness, anorexia/nausea, and dysphagia. In patients with manifest or threatening symptoms radiotherapy (RT) as an effective measure should be implemented into the management concept. Palliative RT radiotherapy prefers short hypofractionated schemas (e.g. 10 x 3 Gy, 4 x 5 Gy, 2 x 8 Gy, 1 x 10 Gy). Careful radiation planning supports the precision of palliative RT and reduces significantly the complication rate. A good response and prolonged palliation effects (6-12 months) can be achieved in many cases. However, the minimum biologically equivalent dose should not be less than 35 Gy. RT produces a good outcome in all types of metastases of lung carcinoma. In emergencies like VCSS or spinal cord compression RT should be initiated immediately. The selection of the optimal therapy for locally advanced lung carcinoma with malignant airway obstruction is difficult. Both brachytherapy and percutaneous irradiation are effective, however published results including local a sum of response, functionality and life quality demonstrates more benefit by percutaneous RT. Due to different physical properties of these two methods the combination of brachytherapy and external beam irradiation may be advantageous. PMID:19955803

  20. A single plan solution to chest wall radiotherapy with bolus?

    PubMed Central

    Ordonez-Sanz, C; Bowles, S; Hirst, A

    2014-01-01

    Objective: Radiotherapy treatments of post-mastectomy chest walls are complex, requiring treatment close to skin, necessitating bolus use. Commonly used 5- and 10-mm-thick boluses develop full skin dose, needing removal for the latter half of treatment and requiring two treatment plans to be generated. Can a thinner bolus be used for all treatment fractions, requiring only one plan? Methods: Investigation of doses received using (A) a half-time 10-mm-thick Vaseline® bolus (current situation); (B) a brass mesh (Whiting & Davis, Attleboro Falls, MA) and (C) 3- and 5-mm Superflab™ (Mick Radio-Nuclear Instruments, Mount Vernon, NY) for 6 and 15 MV. Dosimetric measurements in Barts WT1 solid water and an anthropomorphic phantom, using ionization chambers and thermoluminescent dosemeters, were used to study the effect of different bolus regimes on the photon depth–dose curves (DDCs) and skin doses. Results: Measured skin doses for the current 10-mm-thick Vaseline bolus, brass mesh and 3-mm bolus were compared (5 mm bolus has been rejected). The brass mesh has the least effect on the DDC, with changes <0.7% for depths greater than dmax. Brass mesh conforms superiorly to skin surfaces. Measurements on an anthropomorphic phantom demonstrate an increased skin dose compared with our current treatment protocol. Conclusion: Brass mesh has the smallest effect on the DDC, whilst sufficiently increasing surface dose. It can be removed at any fraction, based on a clinical decision, without the need for generating a new plan. Treating with one plan significantly reduces planning times. Advances in knowledge: Quantification of skin doses required and achieved from wax-on/wax-off treatment compared with alternative available breast boluses. PMID:24646288

  1. 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

    PubMed Central

    Floyd, Scott R.; Kasper, Ekkehard M.; Uhlmann, Erik J.; Fonkem, Ekokobe; Wong, Eric T.; Mahadevan, Anand

    2012-01-01

    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 radiation therapy (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

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

    SciTech Connect

    Siebers, Jeffrey V. . E-mail: jsiebers@vcu.edu; Keall, Paul J.; Wu Qiuwen; Williamson, Jeffrey F.; Schmidt-Ullrich, Rupert K.

    2005-10-01

    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 {sigma} = 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 {sigma} = 1.5 and 3.0 mm along each axis were simulated. Combined systematic and random setup errors were simulated for {sigma} = {sigma} = 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{sub 98}), clinical target volume (CTV) D{sub 90}, nodes D{sub 90}, cord D{sub 2}, and parotid D{sub 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 {sigma} exceeded 3 mm. Simulated systematic setup errors with {sigma} = 1.5 mm resulted in approximately 10% of plan having more than a 3% dose error, whereas a {sigma} = 3.0 mm resulted in half of the plans having

  3. Forward treatment planning for modulated electron radiotherapy (MERT) employing Monte Carlo methods

    SciTech Connect

    Henzen, D. Manser, P.; Frei, D.; Volken, W.; Born, E. J.; Lössl, K.; Aebersold, D. M.; Fix, M. K.; Neuenschwander, H.; Stampanoni, M. F. M.

    2014-03-15

    Purpose: This paper describes the development of a forward planning process for modulated electron radiotherapy (MERT). The approach is based on a previously developed electron beam model used to calculate dose distributions of electron beams shaped by a photon multi leaf collimator (pMLC). Methods: As the electron beam model has already been implemented into the Swiss Monte Carlo Plan environment, the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA) can be included in the planning process for MERT. In a first step, CT data are imported into Eclipse and a pMLC shaped electron beam is set up. This initial electron beam is then divided into segments, with the electron energy in each segment chosen according to the distal depth of the planning target volume (PTV) in beam direction. In order to improve the homogeneity of the dose distribution in the PTV, a feathering process (Gaussian edge feathering) is launched, which results in a number of feathered segments. For each of these segments a dose calculation is performed employing the in-house developed electron beam model along with the macro Monte Carlo dose calculation algorithm. Finally, an automated weight optimization of all segments is carried out and the total dose distribution is read back into Eclipse for display and evaluation. One academic and two clinical situations are investigated for possible benefits of MERT treatment compared to standard treatments performed in our clinics and treatment with a bolus electron conformal (BolusECT) method. Results: The MERT treatment plan of the academic case was superior to the standard single segment electron treatment plan in terms of organs at risk (OAR) sparing. Further, a comparison between an unfeathered and a feathered MERT plan showed better PTV coverage and homogeneity for the feathered plan, with V{sub 95%} increased from 90% to 96% and V{sub 107%} decreased from 8% to nearly 0%. For a clinical breast boost irradiation, the MERT plan

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

    SciTech Connect

    Gentry, John R. . E-mail: gentryj@gmh.org; 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{sup 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{sup 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.

  5. Three-dimensional conformal versus intensity-modulated radiotherapy dose planning in stereotactic radiotherapy: Application of standard quality parameters for plan evaluation

    SciTech Connect

    Grzadziel, Aleksandra; Grosu, Anca-Ligia . E-mail: anca-ligia.grosu@lrz.tum.de; Kneschaurek, Peter

    2006-11-15

    Purpose: The implementation of intensity-modulated radiotherapy (IMRT) technique into clinical practice is becoming routine, but still lacks a generally accepted method for plan evaluation. We present a comparison of the dose distribution of conformal three-dimensional radiotherapy plans with IMRT plans for cranial lesions in stereotactic radiotherapy. The primary aim of this study was to judge the quality of the treatment plans. The next purpose was to assess the usefulness of several quality factors for plan evaluation. Methods and Materials: Five patients, who were treated in our department, were analyzed. Four had meningioma and one had pituitary adenoma. For each case, 10 different plans were created and analyzed: 2 conventional conformal three-dimensional plans and 8 IMRT plans, using the 'step and shoot' delivery method. The first conventional plan was an individually designed beam arrangement and was used for patient treatment. The second plan was a standard plan with the same beam arrangement for all patients. Beam arrangements from the conformal plans were the base for the inversely planned IMRT. To evaluate the plans, the following factors were investigated: minimal and maximal dose to the planning target volume, homogeneity index, coverage index, conformity index, and tumor control probabilities and normal tissue complication probabilities. These quantities were incorporated into scoring factors and assigned to each plan. Results: The greatest homogeneity was reached in the conformal plans and IMRT plans with high planning target volume priority in the optimization process. This consequently led to a better probability of tumor control. Better protection of organs at risk and thereby lower normal tissue complication probabilities were achieved in the IMRT plans with increased weighting of the organs at risk. Conclusion: These results show the efficiency, as well as some limitations, of the IMRT techniques. The use of different quality factors allowed us

  6. Hippocampus-Sparing Whole-Brain Radiotherapy and Simultaneous Integrated Boost for Multiple Brain Metastases From Lung Adenocarcinoma: Early Response and Dosimetric Evaluation.

    PubMed

    Kim, Kyung Hwan; Cho, Byoung Chul; Lee, Chang Geol; Kim, Hye Ryun; Suh, Yang Gun; Kim, Jun Won; Choi, Chihwan; Baek, Jong Geal; Cho, Jaeho

    2016-02-01

    In this study, the volume response and treatment outcome after hippocampus-sparing whole-brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) using tomotherapy were evaluated. Patients with primary lung adenocarcinoma and multiple brain metastases who had a Karnofsky performance status ≥ 70 and exhibited well-controlled extracranial disease were treated. The prescribed dose was administered in 10 to 14 fractions as 25 to 28 Gy to whole-brain parenchyma, as 40 to 48 Gy to the gross metastatic lesion, and as 30 to 42 Gy to a 5-mm margin to the metastatic lesion. Double-dose gadolinium contrast-enhanced magnetic resonance imaging at 1-mm slice thickness was performed before treatment and at 1, 4, and 7 months post-treatment. The tumor volume reduction ratio was calculated for each follow-up. Between July 2011 and September 2012, 11 patients with 70 lesions were included in this analysis. The median number of lesions per patient was 4 (range, 2-15). The median initial tumor volume was 0.235 cm(3) (range, 0.020-10.140 cm(3)). The treatment plans were evaluated regarding conformation number (CN), target coverage (TC), and homogeneity index (HI). The median follow-up duration was 14 months (range, 3-25 months) and the 1-year intracranial control rate was 67%. The tumor volume reduction was most prominent during the first month with a median reduction rate of 0.717 (range, -0.190 to 1.000). Complete remission was seen in 22 (33%) lesions, and 45 (64%) lesions showed more than 65% reduction in tumor volume. The CN, TC, and HI values were comparable to that of previous studies, and the mean hippocampal dose was 13.65 Gy. No treatment breaks or ≥ G3 acute toxicities were observed during or after treatment. The HS-WBRT with SIB in patients with multiple brain metastases was effective and feasible for volume reduction and showed excellent intracranial control. PMID:25601853

  7. The role of PET-CT in radiotherapy planning of solid tumours

    PubMed Central

    Jelercic, Stasa; Rajer, Mirjana

    2015-01-01

    Background PET-CT is becoming more and more important in various aspects of oncology. Until recently it was used mainly as part of diagnostic procedures and for evaluation of treatment results. With development of personalized radiotherapy, volumetric and radiobiological characteristics of individual tumour have become integrated in the multistep radiotherapy (RT) planning process. Standard anatomical imaging used to select and delineate RT target volumes can be enriched by the information on tumour biology gained by PET-CT. In this review we explore the current and possible future role of PET-CT in radiotherapy treatment planning. After general explanation, we assess its role in radiotherapy of those solid tumours for which PET-CT is being used most. Conclusions In the nearby future PET-CT will be an integral part of the most radiotherapy treatment planning procedures in an every-day clinical practice. Apart from a clear role in radiation planning of lung cancer, with forthcoming clinical trials, we will get more evidence of the optimal use of PET-CT in radiotherapy planning of other solid tumours. PMID:25810695

  8. Robotic radiosurgery vs. brachytherapy as a boost to intensity modulated radiotherapy for tonsillar fossa and soft palate tumors: the clinical and economic impact of an emerging technology.

    PubMed

    Nijdam, W; Levendag, P; Fuller, D; Schulz, R; Prevost, J-B; Noever, I; Uyl-de Groot, C

    2007-12-01

    As a basis for making decisions regarding optimal treatment for patients with tonsillar fossa and soft palate tumors, we conducted a preliminary investigation of costs and quality of life (QoL) for two modalities [brachytherapy (BT) and robotic radiosurgery] used to boost radiation to the primary tumors following external beam radiotherapy. BT was well established in our center; a boost by robotic radiosurgery was begun more recently in patients for whom BT was not technically feasible. Robotic radiosurgery boost treatment has the advantage of being non-invasive and is able to reach tumors in cases where there is deep parapharyngeal tumor extension. A neck dissection was performed for patients with nodal-positive disease. Quality of life (pain and difficulty swallowing) was established in long-term follow-up for patients undergoing BT and over a one-year follow-up in robotic radiosurgery patients. Total hospital costs for both groups were computed. Our results show that efficacy and quality of life at one year are comparable for BT and robotic radiosurgery. Total cost for robotic radiosurgery was found to be less than BT primarily due to the elimination of hospital admission and operating room expenses. Confirmation of robotic radiosurgery treatment efficacy and reduced morbidity in the long term requires further study. Quality of life and cost analyses are critical to Health Technology Assessments (HTA). The present study shows how a preliminary HTA of a new medical technology such as robotic radiosurgery with its typical hypofractionation characteristics might be based on short-term clinical outcomes and assumptions of equivalence. PMID:17994791

  9. Intraoperative electron boost radiation followed by moderate doses of external beam radiotherapy in limb-sparing treatment of patients with extremity soft-tissue sarcoma

    SciTech Connect

    Oertel, Susanne; Treiber, Martina; Zahlten-Hinguranage, Angelika; Eichin, Steffen; Roeder, Falk; Funk, Angela; Hensley, Frank W.; Timke, Carmen; Niethammer, Andreas G.; Huber, Peter E.; Weitz, Juergen; Eble, Micheal J.; Buchler, Markus W.; Bernd, Ludger; Debus, Juergen; Krempien, Robert C. . E-mail: robert_krempien@med.uni-heidelberg.de

    2006-04-01

    Purpose: To analyze long-term prognosis and morbidity after limb-sparing treatment of patients with extremity soft-tissue sarcoma, with intraoperative electron boost radiotherapy (IOERT) followed by a moderate dose of external beam radiotherapy (EBRT). Methods and Materials: A total of 153 patients who were treated in a single center from 1991 to 2004 were evaluated. Median IOERT dose was 15 Gy, mean EBRT dose 43 Gy (range, 40-50.4 Gy) in conventional fractionation (1.8-2 Gy). Median duration of follow-up was 33 months. Acute toxicity was assessed with Common Toxicity Criteria; late toxic effects were scored according to European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group criteria. Results: Five-year overall survival and 5-year local control rates were 77% and 78%, respectively. Whereas tumor size, patient age, and EBRT dose did not significantly affect outcome, resection status and grading were significant for survival; resection status and IOERT dose were significant for local control. Extremity salvage until death or time of follow-up was achieved in 90% of our patients, 86% of whom showed excellent limb function without impairment in activities of daily life. Acute toxicity Grade 2-4 was observed in 23% and late toxicity Grade 2-4 in 17% of patients. Conclusions: Treatment with IOERT combined with moderate doses of external beam irradiation yields high local control and extremity preservation rates in resected extremity soft-tissue sarcoma.

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

    PubMed Central

    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

  11. Clinical results of external beam radiotherapy alone with a concomitant boost program or with conventional fractionation for cervical cancer patients who did not receive intracavitary brachytherapy

    PubMed Central

    Matsuura, Kanji; Okabe, Tomoyuki; Fujita, Kazushi; Tanimoto, Hirotoshi; Akagi, Yukio; Kagemoto, Masayuki

    2012-01-01

    A combination of external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT) is well established as the standard radical radiotherapy (RT) for cervical cancer. However, it is sometimes necessary to perform EBRT alone for patients where ICBT is not feasible. For these patients, we initiated EBRT alone with three-dimensional conformal radiotherapy (3DCRT). The purpose of this study is to evaluate the results of EBRT alone without ICBT for patients with cervical cancer. Sixteen patients were treated with EBRT alone between 2002 and 2009. There were three stage IIB, six stage IIIB and seven patients with stage IVA disease. A total of 10 patients were treated with a median dose of 66 Gy with a median overall treatment time (OTT) of 40 days delivered by a concomitant boost (CCB), and a median dose of 60 Gy with a median OTT of 47 days was administered for six patients by conventional fractionation (CF). The 3-year overall survival (OAS) and local control (LC) rates were 43.8% and 75.0%, respectively. The 3-year LC rate was 90.0% for the CCB group, 50.0% for the CF group (P = 0.0692); 100% for OTT ≤42 days, 42.9% for OTT ≥43 days (P = 0.0095). No severe acute and late adverse effects were encountered for any of the patients. These outcomes suggest that EBRT with a CCB program may be a promising radical treatment for cervical cancer that provides better LC with minimal complications, especially in cases where ICBT cannot be performed. PMID:22859563

  12. Analysis of a large number of clinical studies for breast cancer radiotherapy: estimation of radiobiological parameters for treatment planning

    NASA Astrophysics Data System (ADS)

    Guerrero, M.; Li, X. Allen

    2003-10-01

    Numerous studies of early-stage breast cancer treated with breast conserving surgery (BCS) and radiotherapy (RT) have been published in recent years. Both external beam radiotherapy (EBRT) and/or brachytherapy (BT) with different fractionation schemes are currently used. The present RT practice is largely based on empirical experience and it lacks a reliable modelling tool to compare different RT modalities or to design new treatment strategies. The purpose of this work is to derive a plausible set of radiobiological parameters that can be used for RT treatment planning. The derivation is based on existing clinical data and is consistent with the analysis of a large number of published clinical studies on early-stage breast cancer. A large number of published clinical studies on the treatment of early breast cancer with BCS plus RT (including whole breast EBRT with or without a boost to the tumour bed, whole breast EBRT alone, brachytherapy alone) and RT alone are compiled and analysed. The linear quadratic (LQ) model is used in the analysis. Three of these clinical studies are selected to derive a plausible set of LQ parameters. The potential doubling time is set a priori in the derivation according to in vitro measurements from the literature. The impact of considering lower or higher Tpot is investigated. The effects of inhomogeneous dose distributions are considered using clinically representative dose volume histograms. The derived LQ parameters are used to compare a large number of clinical studies using different regimes (e.g., RT modality and/or different fractionation schemes with different prescribed dose) in order to validate their applicability. The values of the equivalent uniform dose (EUD) and biologically effective dose (BED) are used as a common metric to compare the biological effectiveness of each treatment regime. We have obtained a plausible set of radiobiological parameters for breast cancer: agr = 0.3 Gy-1, agr/bgr = 10 Gy and sub

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

    SciTech Connect

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

    2011-11-15

    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 <45 years, 11.8% with Grade III, 11.3% with lymphovascular invasion (LVI), and 26.3% with {>=}4 positive nodes. Corresponding rates in the negative margin cohort were 2.3%, 2.4%, 1.0%, and 2.4%, respectively. On Cox regression analysis of the entire cohort, close or positive margin, Grade III histology, {>=}4 positive nodes, and lack of systemic therapy were significantly associated with higher LR risk. When close/positive margin cases were matched to negative margin controls, the difference in 5-year LR remained significant (4.25% vs. 0.7%, p < 0.001). Conclusions: On univariable analysis, subsets with close or positive margins, in combination with age <45 years, Grade III, LVI, and {>=}4 positive nodes, have 5-year LR >10% despite whole breast plus boost RT. These patients should be considered for

  14. The NUKDOS software for treatment planning in molecular radiotherapy.

    PubMed

    Kletting, Peter; Schimmel, Sebastian; Hänscheid, Heribert; Luster, Markus; Fernández, Maria; Nosske, Dietmar; Lassmann, Michael; Glatting, Gerhard

    2015-09-01

    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 ((90)Y, (131)I or (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(®) 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 differed by 7% and 8

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

    SciTech Connect

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

    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.

  16. SU-E-P-27: Efficient Process for AccuBoost Planning and Treatment Delivery to Minimize Patient Compression Time

    SciTech Connect

    Iftimia, I; Talmadge, M; Halvorsen, P

    2015-06-15

    Purpose: To implement an efficient and robust process for AccuBoost planning and treatment delivery that can be safely performed by a single Physicist while minimizing patient’s total session time. Methods: Following a thorough commissioning and validation process, templates were created in the brachytherapy planning system for each AccuBoost applicator. Tables of individual and total nominal dwell times for each applicator as a function of separation were generated to streamline planning while an Excel-based nomogram provided by the vendor functions as a secondary verification of the treatment parameters. Tables of surface dose as a function of separation and applicator, along with concise guidance documents for applicator selection, are readily available during the planning process. The entire process is described in a set of detailed Standard Operating Procedures which, in addition to the items described above, include a verbal time-out between the primary planner and the individual performing the secondary verification as well as direct visual confirmation of applicator placement using an articulated mirror. Prior to treatment initiation, a final time-out is conducted with the Radiation Oncologist. Chart documentation is finalized after the patient is released from compression following completion of the treatment. Results: With the aforementioned procedures, it has been possible to consistently limit the time required to prepare each treatment such that the patient is typically under compression for less than 10 minutes per orientation prior to the initiation of the treatment, which is particularly important for APBI cases. This process can be overseen by a single physicist assisted by a dosimetrist and has been optimized during the past 16 months, with 180 treatment sessions safely completed to date. Conclusion: This work demonstrates the implementation of an efficient and robust process for real-time-planned AccuBoost treatments that effectively minimizes

  17. Adjuvant Radiotherapy for Gastric Cancer: A Dosimetric Comparison of 3-Dimensional Conformal Radiotherapy, Tomotherapy (registered) and Conventional Intensity Modulated Radiotherapy Treatment Plans

    SciTech Connect

    Dahele, Max; Skinner, Matthew; Schultz, Brenda; Cardoso, Marlene; Bell, Chris; Ung, Yee C.

    2010-07-01

    Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

  18. Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy.

    PubMed

    Goggin, L M; Descovich, M; McGuinness, C; Shiao, S; Pouliot, J; Park, C

    2016-06-01

    Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter

  19. Comparison of long-term survival and toxicity of simultaneous integrated boost vs conventional fractionation with intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma

    PubMed Central

    Tao, Hengmin; Wei, Yumei; Huang, Wei; Gai, Xiujuan; Li, Baosheng

    2016-01-01

    Aim In recent years, the intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB) and intensity-modulated radiotherapy with conventional fractionation (IMRT-CF) have been involved in the treatment of nasopharyngeal carcinoma (NPC). However, the potential clinical effects and toxicities are still controversial. Methods Here, 107 patients with biopsy-proven locally advanced NPC between March 2004 and January 2011 were enrolled in the retrospective study. Among them, 54 patients received IMRT-SIB, and 53 patients received IMRT-CF. Subsequently, overall survival (OS), 5-year progression-free survival (PFS), 5-year locoregional recurrence-free survival (LRFS), and relevant toxicities were analyzed. Results In the present study, all patients completed the treatment, and the overall median follow-up time was 80 months (range: 8–126 months). The 5-year OS analysis revealed no significant difference between the IMRT-SIB and IMRT-CF groups (80.9% vs 80.5%, P=0.568). In addition, there were also no significant between-group differences in 5-year PFS (73.3% vs 74.4%, P=0.773) and 5-year LRFS (88.1% vs 90.8%, P=0.903). Notably, the dose to critical organs (spinal cord, brainstem, and parotid gland) in patients treated by IMRT-CF was significantly lower than that in patients treated by IMRT-SIB (all P<0.05). Conclusion Both IMRT-SIB and IMRT-CF techniques are effective in treating locally advanced NPC, with similar OS, PFS, and LRFS. However, IMRT-CF has more advantages than IMRT-SIB in protecting spinal cord, brainstem, and parotid gland from acute and late toxicities, such as xerostomia. Further prospective study is warranted to confirm our findings. PMID:27099518

  20. Sci—Thur PM: Planning and Delivery — 02: Treatment planning workflow for very high-energy electron beam radiotherapy

    SciTech Connect

    Bazalova, Magdalena; Qu, Bradley; Palma, Bianey; Maxim, Peter; Loo, Billy; Hårdemark, Bjorn; Hynning, Elin

    2014-08-15

    Purpose: To develop treatment planning workflow for rapid radiotherapy delivered with very-high energy electron (VHEE) scanning beam. Methods: VHEE radiotherapy treatment planning was performed by linking Monte Carlo (MC) dose calculations with inverse optimization in a research version of RayStation. In order to study a number of treatment parameters, a Matlab graphical user interface (GUI) for calculation of VHEE beamlet dose was developed. Through the GUI, EGSnrc MC simulations were run for a number of beam energies, number of beams, beamlet spot and grid sizes, and machine bore sizes. VHEE plans for a pediatric patient with a 4.3 cm{sup 3} brain target optimized with spot-scanning algorithm in RayStation were compared to the clinically delivered 6 MV VMAT plan. Results and Discussion: VHEE beam energy had the largest effect on the quality of dose distributions. For the same target dose, the mean doses to critical organs decreased by 10–15% when planned with 100 MeV compared to 60 MeV. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams. While beamlet spacing and bore size had a small effect on VHEE dose distributions, 0.1-3mm beamlet sizes resulted in identical dose distributions. Critical organ doses were by up to 70% lower in the best VHEE plan compared to the clinical 6 MV VMAT plan. Conclusions: We have developed a GUI for MC beamlet generation for treatment planning of VHEE radiotherapy. We have demonstrated that pediatric VHEE plans resulted in significant critical organ dose sparing compared to the clinical VMAT plan.

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

    SciTech Connect

    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. . E-mail: elin@u.washington.edu

    2006-11-01

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

    SciTech Connect

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

    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

  3. Dosimetric Evaluation of a Simple Planning Technique for Improving Intensity-Modulated Radiotherapy for Nasopharyngeal Cancer

    PubMed Central

    Xie, Wen-Jia; Xie, Liang-Xi

    2015-01-01

    Purpose To evaluate the dosimetric outcomes of a simple planning technique for improving intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer (NPC). Methods For 39 NPC cases, generally acceptable original plans were generated and were improved by the two planning techniques, respectively: (1) a basal-dose-compensation (BDC) technique, in which the treatment plans were re-optimized based on the original plans; (2) a local-dose-control (LDC) technique, in which the original plans were re-optimized with constraints for hot and cold spots. The BDC, original, and LDC plans were then compared regarding homogeneity index (HI) and conformity index (CI) of planning target volumes (PTVs), organ-at-risk (OAR) sparing and monitor units (MUs) per fraction. The whole planning times were also compared between the BDC and LDC plans. Results The BDC plans had superior HIs / CIs, by 13-24% / 3-243%, respectively, over the original plans. Compared to the LDC plans, the BDC plans provided better HIs only for PTVnx (the PTV of nasopharyngeal primary tumor) by 11% and better CIs for all PTVs by 2-134%. The BDC technique spared most OARs, by 1-9%. The average MUs of the BDC, original, and LDC plans were 2149, 2068 and 2179, respectively. The average whole planning times were 48 and 69 minutes for the BDC and LDC plans, respectively. Conclusions For the IMRT of nasopharyngeal cancer, the BDC planning technique can improve target dose homogeneity, conformity and OAR sparing, with better planning efficiency. PMID:26132167

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

    SciTech Connect

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

    2008-10-01

    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{sup 3}) and stomach (0.5 cm{sup 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{sup 3}) already receiving 54 Gy, the maximal prescription dose allowed. In the remaining cases, the PTV range was 9.6-689 cm{sup 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.

  5. External Beam Radiotherapy With Endocavitary Boost for Nasopharyngeal Cancer: Treatment Results and Late Toxicity After Extended Follow-Up

    SciTech Connect

    Schinagl, Dominic A.X.; Marres, Henri A.M.; Kappelle, Arnoud C.; Merkx, Matthias A.W.; Pop, Lucas A.M.; Verstappen, Suzan M.M.; Kaanders, Johannes H.A.M.

    2010-11-01

    Purpose: To evaluate the long-term outcome after treatment of nasopharyngeal carcinoma and assess late toxicity in a multidisciplinary clinic. Methods and Materials: A retrospective analysis of 117 patients treated for nasopharyngeal cancer in a single institute between 1985 and 2002 was performed. Fifty-one long-term survivors were evaluated for late toxicity by a multidisciplinary team comprising a radiation oncologist, otolaryngologist, neurologist, and oral and maxillofacial surgeon. Results: The 5-year local control rate for T1 to T2 and T3 to T4 tumors was 97% and 76%, respectively. Five-year disease-free survival and overall survival were 82% and 88% for Stage I to IIb disease and 46% and 52% for Stage III to IVb, respectively. Late morbidity evaluation revealed Radiation Therapy Oncology Group (RTOG) Grade III to IV toxicity in 71% of patients. A high incidence of cranial nerve palsies (47%) and mandibular osteolysis (82%) was found, although these complications had limited clinical impact. Conclusions: The multidisciplinary late morbidity clinic revealed an unexpected high incidence of cranial nerve palsies and mandibular osteolysis and overall an RTOG Grade III to IV toxicity in 71% of patients treated for nasopharyngeal cancer. External beam radiotherapy with endocavitary brachytherapy produces excellent rates of local control for T1 to T2 tumors, but the high incidence of late toxicity suggests an overtreatment.

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    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.

  7. Automated planning of breast radiotherapy using cone beam CT imaging

    SciTech Connect

    Amit, Guy; Purdie, Thomas G.

    2015-02-15

    Purpose: Develop and clinically validate a methodology for using cone beam computed tomography (CBCT) imaging in an automated treatment planning framework for breast IMRT. Methods: A technique for intensity correction of CBCT images was developed and evaluated. The technique is based on histogram matching of CBCT image sets, using information from “similar” planning CT image sets from a database of paired CBCT and CT image sets (n = 38). Automated treatment plans were generated for a testing subset (n = 15) on the planning CT and the corrected CBCT. The plans generated on the corrected CBCT were compared to the CT-based plans in terms of beam parameters, dosimetric indices, and dose distributions. Results: The corrected CBCT images showed considerable similarity to their corresponding planning CTs (average mutual information 1.0±0.1, average sum of absolute differences 185 ± 38). The automated CBCT-based plans were clinically acceptable, as well as equivalent to the CT-based plans with average gantry angle difference of 0.99°±1.1°, target volume overlap index (Dice) of 0.89±0.04 although with slightly higher maximum target doses (4482±90 vs 4560±84, P < 0.05). Gamma index analysis (3%, 3 mm) showed that the CBCT-based plans had the same dose distribution as plans calculated with the same beams on the registered planning CTs (average gamma index 0.12±0.04, gamma <1 in 99.4%±0.3%). Conclusions: The proposed method demonstrates the potential for a clinically feasible and efficient online adaptive breast IMRT planning method based on CBCT imaging, integrating automation.

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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.

  9. Evaluations of an adaptive planning technique incorporating dose feedback in image-guided radiotherapy of prostate cancer

    SciTech Connect

    Liu Han; Wu Qiuwen

    2011-12-15

    Purpose: Online image guidance (IG) has been used to effectively correct the setup error and inter-fraction rigid organ motion for prostate cancer. However, planning margins are still necessary to account for uncertainties such as deformation and intra-fraction motion. The purpose of this study is to investigate the effectiveness of an adaptive planning technique incorporating offline dose feedback to manage inter-fraction motion and residuals from online correction. Methods: Repeated helical CT scans from 28 patients were included in the study. The contours of prostate and organs-at-risk (OARs) were delineated on each CT, and online IG was simulated by matching center-of-mass of prostate between treatment CTs and planning CT. A seven beam intensity modulated radiation therapy (IMRT) plan was designed for each patient on planning CT for a total of 15 fractions. Dose distribution at each fraction was evaluated based on actual contours of the target and OARs from that fraction. Cumulative dose up to each fraction was calculated by tracking each voxel based on a deformable registration algorithm. The cumulative dose was compared with the dose from initial plan. If the deviation exceeded the pre-defined threshold, such as 2% of the D{sub 99} to the prostate, an adaptive planning technique called dose compensation was invoked, in which the cumulative dose distribution was fed back to the treatment planning system and the dose deficit was made up through boost radiation in future treatment fractions. The dose compensation was achieved by IMRT inverse planning. Two weekly compensation delivery strategies were simulated: one intended to deliver the boost dose in all future fractions (schedule A) and the other in the following week only (schedule B). The D{sub 99} to prostate and generalized equivalent uniform dose (gEUD) to rectal wall and bladder were computed and compared with those without the dose compensation. Results: If only 2% underdose is allowed at the end of the

  10. Computer-assisted targeted therapy (CATT) for prostate radiotherapy planning by fusion of CT and MRI

    NASA Astrophysics Data System (ADS)

    Chappelow, Jonathan; Both, Stefan; Viswanath, Satish; Hahn, Stephen; Feldman, Michael; Rosen, Mark; Tomaszewski, John; Vapiwala, Neha; Patel, Pratik; Madabhushi, Anant

    2010-02-01

    In this paper, we present a comprehensive, quantitative imaging framework for improved treatment of prostate cancer via computer-assisted targeted therapy (CATT) to facilitate radiotherapy dose escalation to regions with a high likelihood of disease presence. The framework involves identification of high likelihood prostate cancer regions using computer-aided detection (CAD) classifier on diagnostic MRI, followed by mapping of these regions from MRI onto planning computerized tomography (CT) via image registration. Treatment of prostate cancer by targeted radiotherapy requires CT to formulate a dose plan. While accurate delineation of the prostate and cancer can provide reduced exposure of benign tissue to radiation, as well as a higher dose to the cancer, CT is ineffective in localizing intraprostatic lesions and poor for highlighting the prostate boundary. MR imagery on the other hand allows for greatly improved visualization of the prostate. Further, several studies have demonstrated the utility of CAD for identifying the location of tumors on in vivo multi-functional prostate MRI. Consequently, our objective is to improve the accuracy of radiotherapy dose plans via multimodal fusion of MR and CT. To achieve this objective, the CATT framework presented in this paper comprises the following components: (1) an unsupervised pixel-wise classifier to identify suspicious regions within the prostate on diagnostic MRI, (2) elastic image registration to align corresponding diagnostic MRI, planning MRI, and CT of the prostate, (3) mapping of the suspect regions from diagnostic MRI onto CT, and (4) calculation of a modified radiotherapy plan with escalated dose for cancer. Qualitative comparison of the dose plans (with and without CAD) over a total of 79 2D slices obtained from 10 MR-CT patient studies, suggest that our CATT framework could help in improved targeted treatment of prostate cancer.

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

    PubMed Central

    2011-01-01

    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. PMID:21554675

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

    SciTech Connect

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

    2014-06-15

    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

  13. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    SciTech Connect

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G. E-mail: BWLoo@Stanford.edu; Loo, Billy W. E-mail: BWLoo@Stanford.edu; Hårdemark, Björn; Hynning, Elin

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  14. IMRT boost dose planning on dominant intraprostatic lesions: Gold marker-based three-dimensional fusion of CT with dynamic contrast-enhanced and {sup 1}H-spectroscopic MRI

    SciTech Connect

    Lin, Emile N.J.T. van . E-mail: E.vanLin@rther.umcn.nl; Fuetterer, Jurgen J.; Heijmink, Stijn W.T.P.J.; Vight, Lisette P. van der; Hoffmann, Aswin L.; Kollenburg, Peter van; Huisman, Henk Jan J.; Scheenen, Tom W.J.; Witjes, J. Alfred; Leer, Jan Willem; Barentsz, Jelle O.; Visser, Andries G.

    2006-05-01

    Purpose: To demonstrate the theoretical feasibility of integrating two functional prostate magnetic resonance imaging (MRI) techniques (dynamic contrast-enhanced MRI [DCE-MRI] and {sup 1}H-spectroscopic MRI [MRSI]) into inverse treatment planning for definition and potential irradiation of a dominant intraprostatic lesion (DIL) as a biologic target volume for high-dose intraprostatic boosting with intensity-modulated radiotherapy (IMRT). Methods and Materials: In 5 patients, four gold markers were implanted. An endorectal balloon was inserted for both CT and MRI. A DIL volume was defined by DCE-MRI and MRSI using different prostate cancer-specific physiologic (DCE-MRI) and metabolic (MRSI) parameters. CT-MRI registration was performed automatically by matching three-dimensional gold marker surface models with the iterative closest point method. DIL-IMRT plans, consisting of whole prostate irradiation to 70 Gy and a DIL boost to 90 Gy, and standard IMRT plans, in which the whole prostate was irradiated to 78 Gy were generated. The tumor control probability and rectal wall normal tissue complication probability were calculated and compared between the two IMRT approaches. Results: Combined DCE-MRI and MRSI yielded a clearly defined single DIL volume (range, 1.1-6.5 cm{sup 3}) in all patients. In this small, selected patient population, no differences in tumor control probability were found. A decrease in the rectal wall normal tissue complication probability was observed in favor of the DIL-IMRT plan versus the plan with IMRT to 78 Gy. Conclusion: Combined DCE-MRI and MRSI functional image-guided high-dose intraprostatic DIL-IMRT planned as a boost to 90 Gy is theoretically feasible. The preliminary results have indicated that DIL-IMRT may improve the therapeutic ratio by decreasing the normal tissue complication probability with an unchanged tumor control probability. A larger patient population, with more variations in the number, size, and localization of the DIL

  15. Equivalent Biochemical Control and Improved Prostate-Specific Antigen Nadir After Permanent Prostate Seed Implant Brachytherapy Versus High-Dose Three-Dimensional Conformal Radiotherapy and High-Dose Conformal Proton Beam Radiotherapy Boost

    SciTech Connect

    Jabbari, Siavash; Weinberg, Vivian K.; Shinohara, Katsuto; Speight, Joycelyn L.; Gottschalk, Alexander R.; Hsu, I.-C.; Pickett, Barby; McLaughlin, Patrick W.; Sandler, Howard M.; Roach, Mack

    2010-01-15

    Purpose: Permanent prostate implant brachytherapy (PPI), three-dimensional conformal radiotherapy (3D-CRT), and conformal proton beam radiotherapy (CPBRT) are used in the treatment of localized prostate cancer, although no head-to-head trials have compared these modalities. We studied the biochemical control (biochemical no evidence of disease [bNED]) and prostate-specific antigen (PSA) nadir achieved with contemporary PPI, and evaluated it against 3D-CRT and CPBRT. Patients and Methods: A total of 249 patients were treated with PPI at the University of California, San Francisco, and the outcomes were compared with those from a 3D-CRT cohort and the published results of a high-dose CPBRT boost (CPBRTB) trial. For each comparison, subsets of the PPI cohort were selected with patient and disease criteria similar to those of the reference group. Results: With a median follow-up of 5.3 years, the bNED rate at 5 and 7 years achieved with PPI was 92% and 86%, respectively, using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, and 93% using the PSA nadir plus 2 ng/mL definition. Using the ASTRO definition, a 5-year bNED rate of 78% was achieved for the 3D-CRT patients compared with 94% for a comparable PPI subset and 93% vs. 92%, respectively, using the PSA nadir plus 2 ng/mL definition. The median PSA nadir for patients treated with PPI and 3D-CRT was 0.10 and 0.40 ng/mL, respectively (p < .0001). For the CPBRT comparison, the 5-year bNED rate after a CPBRTB was 91% using the ASTRO definition vs. 93% for a similar group of PPI patients. A greater proportion of PPI patients achieved a lower PSA nadir compared with those achieved in the CPBRTB trial (PSA nadir <=0.5 ng/mL, 91% vs. 59%, respectively). Conclusion: We have demonstrated excellent outcomes in low- to intermediate-risk patients treated with PPI, suggesting at least equivalent 5-year bNED rates and a greater proportion of men achieving lower PSA nadirs compared with 3D-CRT or

  16. Automated Planning of Tangential Breast Intensity-Modulated Radiotherapy Using Heuristic Optimization

    SciTech Connect

    Purdie, Thomas G.; Dinniwell, Robert E.; Letourneau, Daniel; Hill, Christine; Sharpe, Michael B.

    2011-10-01

    Purpose: To present an automated technique for two-field tangential breast intensity-modulated radiotherapy (IMRT) treatment planning. Method and Materials: A total of 158 planned patients with Stage 0, I, and II breast cancer treated using whole-breast IMRT were retrospectively replanned using automated treatment planning tools. The tools developed are integrated into the existing clinical treatment planning system (Pinnacle{sup 3}) and are designed to perform the manual volume delineation, beam placement, and IMRT treatment planning steps carried out by the treatment planning radiation therapist. The automated algorithm, using only the radio-opaque markers placed at CT simulation as inputs, optimizes the tangential beam parameters to geometrically minimize the amount of lung and heart treated while covering the whole-breast volume. The IMRT parameters are optimized according to the automatically delineated whole-breast volume. Results: The mean time to generate a complete treatment plan was 6 min, 50 s {+-} 1 min 12 s. For the automated plans, 157 of 158 plans (99%) were deemed clinically acceptable, and 138 of 158 plans (87%) were deemed clinically improved or equal to the corresponding clinical plan when reviewed in a randomized, double-blinded study by one experienced breast radiation oncologist. In addition, overall the automated plans were dosimetrically equivalent to the clinical plans when scored for target coverage and lung and heart doses. Conclusion: We have developed robust and efficient automated tools for fully inversed planned tangential breast IMRT planning that can be readily integrated into clinical practice. The tools produce clinically acceptable plans using only the common anatomic landmarks from the CT simulation process as an input. We anticipate the tools will improve patient access to high-quality IMRT treatment by simplifying the planning process and will reduce the effort and cost of incorporating more advanced planning into clinical

  17. Development and Evaluation of Multiple Isocentric Volumetric Modulated Arc Therapy Technique for Craniospinal Axis Radiotherapy Planning

    SciTech Connect

    Lee, Young K.; Brooks, Corrinne J.; Bedford, James L.; Warrington, Alan P.; Saran, Frank H.

    2012-02-01

    Purpose: To develop and compare a volumetric modulated arc therapy (VMAT) technique with conventional radiotherapy for craniospinal irradiation with respect to improved dose conformity and homogeneity in the planning target volume (PTV) and to reduced dose to organs at risk (OAR). Methods and Materials: Conventional craniospinal axis radiotherapy plans of 5 patients were acquired. The median (range) length of the PTV was 58.9 (48.1-83.7) cm. The 6-MV VMAT plans were inversely planned with one isocenter near the base of the brain and the minimum number of isocenters required for the specified lengths of spine. The plans were optimized with high weighting for PTV coverage and low weighting for OAR sparing. Conformity and heterogeneity indices, dose-volume histograms, mean doses, and non-PTV integral doses from the two plans (prescription dose 23.4 Gy in 13 fractions) were compared. Results: The median (range) conformity index of VMAT was 1.22 (1.09-1.45), compared with 1.69 (1.44-2.67) for conventional plans (p = 0.04). The median (range) heterogeneity index was also lower for VMAT compared with conventional plans: 1.04 (1.03-1.07) vs. 1.12 (1.09-1.19), respectively (p = 0.04). A significant reduction of mean and maximum doses was observed in the heart, thyroid, esophagus, optic nerves, and eyes with VMAT when compared with conventional plans. A decrease in body V{sub 10Gy} was observed, but for 4 of 5 patients non-PTV integral dose was increased with VMAT when compared with the conventional plans. Conclusions: A VMAT technique to treat the craniospinal axis significantly reduces OAR dose, potentially leading to lower late organ toxicity. However, this is achieved at the expense of increased low-dose volumes, which is inherent to the technique, carrying a potentially increased risk of secondary malignancies.

  18. Monte Carlo calculation of dose distributions in oligometastatic patients planned for spine stereotactic ablative radiotherapy

    NASA Astrophysics Data System (ADS)

    Moiseenko, V.; Liu, M.; Loewen, S.; Kosztyla, R.; Vollans, E.; Lucido, J.; Fong, M.; Vellani, R.; Popescu, I. A.

    2013-10-01

    Dosimetric consequences of plans optimized using the analytical anisotropic algorithm (AAA) implemented in the Varian Eclipse treatment planning system for spine stereotactic body radiotherapy were evaluated by re-calculating with BEAMnrc/DOSXYZnrc Monte Carlo. Six patients with spinal vertebral metastases were planned using volumetric modulated arc therapy. The planning goal was to cover at least 80% of the planning target volume with a prescribed dose of 35 Gy in five fractions. Tissue heterogeneity-corrected AAA dose distributions for the planning target volume and spinal canal planning organ-at-risk volume were compared against those obtained from Monte Carlo. The results showed that the AAA overestimated planning target volume coverage with the prescribed dose by up to 13.5% (mean 8.3% +/- 3.2%) when compared to Monte Carlo simulations. Maximum dose to spinal canal planning organ-at-risk volume calculated with Monte Carlo was consistently smaller than calculated with the treatment planning system and remained under spinal cord dose tolerance. Differences in dose distribution appear to be related to the dosimetric effects of accounting for body composition in Monte Carlo simulations. In contrast, the treatment planning system assumes that all tissues are water-equivalent in their composition and only differ in their electron density.

  19. Influence of 11C-choline PET/CT on radiotherapy planning in prostate cancer

    PubMed Central

    López, Escarlata; Lazo, Antonio; Gutiérrez, Antonio; Arregui, Gregorio; Núñez, Isabel; Sacchetti, Antonio

    2014-01-01

    Aim To evaluate the influence of 11C-choline PET/CT on radiotherapy planning in prostate cancer patients. Background Precise information on the extension of prostate cancer is crucial for the choice of an appropriate therapeutic strategy. 11C-choline positron emission tomography (11C-choline PET/CT) has two roles in radiation oncology (RT): (1) patient selection for treatment and (2) target volume selection and delineation. In conjunction with high-accuracy techniques, it might offer an opportunity of dose escalation and better tumour control while sparing healthy tissues. Materials and methods We carried out a retrospective study in order to analyse RT planning modification based on 11C-choline PET/CT in 16 prostate cancer patients. Patients were treated with hypofractionated step-and-shoot Intensity Modulated Radiotherapy (IMRT), or Volumetric Modulated Arc Therapy (VMAT), and a daily cone-beam CT for Image Guided Radiation Therapy (IGRT). All patients underwent a 11C-choline-PET/CT scan prior to radiotherapy. Results In 37.5% of cases, a re-delineation and new dose prescription occurred. Data show good preliminary clinical results in terms of biochemical control and toxicity. No gastrointestinal (GI)/genitourinary (GU) grade III toxicities were observed after a median follow-up of 9.5 months. Conclusions In our experience, concerning the treatment of prostate cancer (PCa), 11C-choline PET/CT may be helpful in radiotherapy planning, either for dose escalation or exclusion of selected sites. PMID:25859399

  20. PET/CT for Radiotherapy Treatment Planning in Patients With Soft Tissue Sarcomas

    SciTech Connect

    Karam, Irene; Devic, Slobodan; Hickeson, Marc; Roberge, David; Turcotte, Robert E.; Freeman, Carolyn R.

    2009-11-01

    Purpose: To study the possibility of incorporating positron emission tomography/computed tomography (PET/CT) information into radiotherapy treatment planning in patients with high-grade soft tissue sarcomas (STS). Methods and Materials: We studied 17 patients treated with preoperative radiotherapy at our institution from 2005 to 2007. All patients had a high-grade STS and had had a staging PET/CT scan. For each patient, an MRI-based gross tumor volume (GTV), considered to be the contemporary standard for radiotherapy treatment planning, was outlined on a T1-gadolinium enhanced axial MRI (GTV{sub MRI}), and a second set of GTVs were outlined using different threshold values on PET images (GTV{sub PET}). PET-based target volumes were compared with the MRI-based GTV. Threshold values for target contouring were determined as a multiple (from 2 to 10 times) of the background soft tissue uptake values (B) sampled over healthy tissue. Results: PET-based GTVs contoured using a threshold value of 2 or 2.5 most closely resembled the GTV{sub MRI} volumes. Higher threshold values lead to PET volumes much smaller than the GTV{sub MRI}. The standard deviations between the average volumes of GTV{sub PET} and GTV{sub MRI} ratios for all thresholds were large, ranging from 36% for 2 xB up to 93% for 10 xB. Maximum uptake-to-background ratio correlated poorly with the maximum standardized uptake values. Conclusions: It is unlikely that PET/CT will make a significant contribution in GTV definition for radiotherapy treatment planning in patients with STS using threshold methods on PET images. Future studies will focus on molecular imaging and tumor physiology.

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

    PubMed Central

    Eley, John; Newhauser, Wayne; Homann, Kenneth; Howell, Rebecca; Schneider, Christopher; Durante, Marco; Bert, Christoph

    2015-01-01

    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. PMID:25768061

  2. Implementation of an analytical model for leakage neutron equivalent dose in a proton radiotherapy planning system.

    PubMed

    Eley, John; Newhauser, Wayne; Homann, Kenneth; Howell, Rebecca; Schneider, Christopher; Durante, Marco; Bert, Christoph

    2015-01-01

    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. PMID:25768061

  3. An integrated Monte Carlo dosimetric verification system for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Mizowaki, T.; Miyabe, Y.; Takegawa, H.; Narita, Y.; Yano, S.; Nagata, Y.; Teshima, T.; Hiraoka, M.

    2007-04-01

    An integrated Monte Carlo (MC) dose calculation system, MCRTV (Monte Carlo for radiotherapy treatment plan verification), has been developed for clinical treatment plan verification, especially for routine quality assurance (QA) of intensity-modulated radiotherapy (IMRT) plans. The MCRTV system consists of the EGS4/PRESTA MC codes originally written for particle transport through the accelerator, the multileaf collimator (MLC), and the patient/phantom, which run on a 28-CPU Linux cluster, and the associated software developed for the clinical implementation. MCRTV has an interface with a commercial treatment planning system (TPS) (Eclipse, Varian Medical Systems, Palo Alto, CA, USA) and reads the information needed for MC computation transferred in DICOM-RT format. The key features of MCRTV have been presented in detail in this paper. The phase-space data of our 15 MV photon beam from a Varian Clinac 2300C/D have been developed and several benchmarks have been performed under homogeneous and several inhomogeneous conditions (including water, aluminium, lung and bone media). The MC results agreed with the ionization chamber measurements to within 1% and 2% for homogeneous and inhomogeneous conditions, respectively. The MC calculation for a clinical prostate IMRT treatment plan validated the implementation of the beams and the patient/phantom configuration in MCRTV.

  4. Monte Carlo Treatment Planning for Molecular Targeted Radiotherapy within the MINERVA System

    SciTech Connect

    Lehmann, J; Siantar, C H; Wessol, D E; Wemple, C A; Nigg, D; Cogliati, J; Daly, T; Descalle, M; Flickinger, T; Pletcher, D; DeNardo, G

    2004-09-22

    The aim of this project is to extend accurate and patient-specific treatment planning to new treatment modalities, such as molecular targeted radiation therapy, incorporating previously crafted and proven Monte Carlo and deterministic computation methods. A flexible software environment is being created that allows planning radiation treatment for these new modalities and combining different forms of radiation treatment with consideration of biological effects. The system uses common input interfaces, medical image sets for definition of patient geometry, and dose reporting protocols. Previously, the Idaho National Engineering and Environmental Laboratory (INEEL), Montana State University (MSU), and Lawrence Livermore National Laboratory (LLNL) had accrued experience in the development and application of Monte Carlo-based, three-dimensional, computational dosimetry and treatment planning tools for radiotherapy in several specialized areas. In particular, INEEL and MSU have developed computational dosimetry systems for neutron radiotherapy and neutron capture therapy, while LLNL has developed the PEREGRINE computational system for external beam photon-electron therapy. Building on that experience, the INEEL and MSU are developing the MINERVA (Modality Inclusive Environment for Radiotherapeutic Variable Analysis) software system as a general framework for computational dosimetry and treatment planning for a variety of emerging forms of radiotherapy. In collaboration with this development, LLNL has extended its PEREGRINE code to accommodate internal sources for molecular targeted radiotherapy (MTR), and has interfaced it with the plug-in architecture of MINERVA. Results from the extended PEREGRINE code have been compared to published data from other codes, and found to be in general agreement (EGS4 - 2%, MCNP - 10%)(Descalle et al. 2003). The code is currently being benchmarked against experimental data. The interpatient variability of the drug pharmacokinetics in MTR

  5. Monte Carlo treatment planning for molecular targeted radiotherapy within the MINERVA system.

    PubMed

    Lehmann, Joerg; Hartmann Siantar, Christine; Wessol, Daniel E; Wemple, Charles A; Nigg, David; Cogliati, Josh; Daly, Tom; Descalle, Marie-Anne; Flickinger, Terry; Pletcher, David; Denardo, Gerald

    2005-03-01

    The aim of this project is to extend accurate and patient-specific treatment planning to new treatment modalities, such as molecular targeted radiation therapy, incorporating previously crafted and proven Monte Carlo and deterministic computation methods. A flexible software environment is being created that allows planning radiation treatment for these new modalities and combining different forms of radiation treatment with consideration of biological effects. The system uses common input interfaces, medical image sets for definition of patient geometry and dose reporting protocols. Previously, the Idaho National Engineering and Environmental Laboratory (INEEL), Montana State University (MSU) and Lawrence Livermore National Laboratory (LLNL) had accrued experience in the development and application of Monte Carlo based, three-dimensional, computational dosimetry and treatment planning tools for radiotherapy in several specialized areas. In particular, INEEL and MSU have developed computational dosimetry systems for neutron radiotherapy and neutron capture therapy, while LLNL has developed the PEREGRINE computational system for external beam photon-electron therapy. Building on that experience, the INEEL and MSU are developing the MINERVA (modality inclusive environment for radiotherapeutic variable analysis) software system as a general framework for computational dosimetry and treatment planning for a variety of emerging forms of radiotherapy. In collaboration with this development, LLNL has extended its PEREGRINE code to accommodate internal sources for molecular targeted radiotherapy (MTR), and has interfaced it with the plugin architecture of MINERVA. Results from the extended PEREGRINE code have been compared to published data from other codes, and found to be in general agreement (EGS4-2%, MCNP-10%) (Descalle et al 2003 Cancer Biother. Radiopharm. 18 71-9). The code is currently being benchmarked against experimental data. The interpatient variability of the

  6. Evaluation of the radiotherapy treatment planning in the presence of a magnetic valve tissue expander.

    PubMed

    Trombetta, Débora M; Cardoso, Simone C; Alves, Victor G L; Facure, Alessandro; Batista, Delano V S; da Silva, Ademir X

    2015-01-01

    The combination of radiotherapy treatments and breast reconstruction, using temporary tissue expanders, generates several concerns due to the presence of a magnetic valve inside the radiation field. The objective of this work is to evaluate a radiotherapy treatment planning for a patient using a tissue expander. Isodose curve maps, obtained using radiochromic films, were compared to the ones calculated with two different dose calculation algorithms of the Eclipse radiotherapy Treatment Planning System (TPS), considering the presence or absence of the heterogeneity. The TPS calculation considering the presence of the heterogeneity shows changes around 5% in the isodose curves when they were compared with the calculation without heterogeneity correction. This calculation did not take in account the real density value of the heterogeneity. This limitation was quantified to be around 10% in comparison with the TPS calculation and experimental measurements using the radiochromic film. These results show that the magnetic valve should be taken in account in dose calculations of the TPS. With respect to the AAA and Pencil Beam Convolution algorithms, when the calculation is compared with the real distribution, AAA presents a distribution more similar to experimental dose distribution. PMID:25679529

  7. Evaluation of the Radiotherapy Treatment Planning in the Presence of a Magnetic Valve Tissue Expander

    PubMed Central

    Trombetta, Débora M.; Cardoso, Simone C.; Alves, Victor G. L.; Facure, Alessandro; Batista, Delano V. S.; da Silva, Ademir X.

    2015-01-01

    The combination of radiotherapy treatments and breast reconstruction, using temporary tissue expanders, generates several concerns due to the presence of a magnetic valve inside the radiation field. The objective of this work is to evaluate a radiotherapy treatment planning for a patient using a tissue expander. Isodose curve maps, obtained using radiochromic films, were compared to the ones calculated with two different dose calculation algorithms of the Eclipse radiotherapy Treatment Planning System (TPS), considering the presence or absence of the heterogeneity. The TPS calculation considering the presence of the heterogeneity shows changes around 5% in the isodose curves when they were compared with the calculation without heterogeneity correction. This calculation did not take in account the real density value of the heterogeneity. This limitation was quantified to be around 10% in comparison with the TPS calculation and experimental measurements using the radiochromic film. These results show that the magnetic valve should be taken in account in dose calculations of the TPS. With respect to the AAA and Pencil Beam Convolution algorithms, when the calculation is compared with the real distribution, AAA presents a distribution more similar to experimental dose distribution. PMID:25679529

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

    NASA Astrophysics Data System (ADS)

    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 workflow: 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 workflow. 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.

  9. Dose calculation accuracies in whole breast radiotherapy treatment planning: a multi-institutional study.

    PubMed

    Hatanaka, Shogo; Miyabe, Yuki; Tohyama, Naoki; Kumazaki, Yu; Kurooka, Masahiko; Okamoto, Hiroyuki; Tachibana, Hidenobu; Kito, Satoshi; Wakita, Akihisa; Ohotomo, Yuko; Ikagawa, Hiroyuki; Ishikura, Satoshi; Nozaki, Miwako; Kagami, Yoshikazu; Hiraoka, Masahiro; Nishio, Teiji

    2015-07-01

    Our objective in this study was to evaluate the variation in the doses delivered among institutions due to dose calculation inaccuracies in whole breast radiotherapy. We have developed practical procedures for quality assurance (QA) of radiation treatment planning systems. These QA procedures are designed to be performed easily at any institution and to permit comparisons of results across institutions. The dose calculation accuracy was evaluated across seven institutions using various irradiation conditions. In some conditions, there was a >3 % difference between the calculated dose and the measured dose. The dose calculation accuracy differs among institutions because it is dependent on both the dose calculation algorithm and beam modeling. The QA procedures in this study are useful for verifying the accuracy of the dose calculation algorithm and of the beam model before clinical use for whole breast radiotherapy. PMID:25646770

  10. Iterative reconstruction of volumetric modulated arc radiotherapy plans using control point basis vectors

    NASA Astrophysics Data System (ADS)

    Barbiere, Joseph C.; Kapulsky, Alexander; Ndlovu, Alois

    2014-03-01

    Volumetric Modulated Arc Radiotherapy is an innovative technique currently utilized to efficiently deliver complex treatments. Dose rate, speed of rotation, and field shape are continuously varied as the radiation source rotates about the patient. Patient specific quality assurance is performed to verify that the delivered dose distribution is consistent with the plan formulated in a treatment planning system. The purpose of this work is to present novel methodology using a Gafchromic EBT3 film image of a patient plan in a cylindrical phantom and calculating the delivered MU per control point. Images of two dimensional plan dose matrices and film scans are analyzed using MATLAB with the imaging toolbox. Dose profiles in a ring corresponding to the film position are extracted from the plan matrices for comparison with the corresponding measured film dose. The plan is made up of a series of individual static Control Points. If we consider these Control Points a set of basis vectors, then variations in the plan can be represented as the weighted sum of the basis. The weighing coefficients representing the actual delivered MU can be determined by any available optimization tool, such as downhill simplex or non-linear programming. In essence we reconstruct an image of the delivered dose. Clinical quality assurance is performed with this technique by computing a patient plan with the measured monitor units and standard plan evaluation tools such as Dose Volume Histograms. Testing of the algorithm with known changes in the reference images indicated a correlation coefficient greater than 0.99.

  11. Multiobjective optimization with a modified simulated annealing algorithm for external beam radiotherapy treatment planning

    SciTech Connect

    Aubry, Jean-Francois; Beaulieu, Frederic; Sevigny, Caroline; Beaulieu, Luc; Tremblay, Daniel

    2006-12-15

    Inverse planning in external beam radiotherapy often requires a scalar objective function that incorporates importance factors to mimic the planner's preferences between conflicting objectives. Defining those importance factors is not straightforward, and frequently leads to an iterative process in which the importance factors become variables of the optimization problem. In order to avoid this drawback of inverse planning, optimization using algorithms more suited to multiobjective optimization, such as evolutionary algorithms, has been suggested. However, much inverse planning software, including one based on simulated annealing developed at our institution, does not include multiobjective-oriented algorithms. This work investigates the performance of a modified simulated annealing algorithm used to drive aperture-based intensity-modulated radiotherapy inverse planning software in a multiobjective optimization framework. For a few test cases involving gastric cancer patients, the use of this new algorithm leads to an increase in optimization speed of a little more than a factor of 2 over a conventional simulated annealing algorithm, while giving a close approximation of the solutions produced by a standard simulated annealing. A simple graphical user interface designed to facilitate the decision-making process that follows an optimization is also presented.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. A maximum-entropy method for the planning of conformal radiotherapy.

    PubMed

    Wu, X; Zhu, Y

    2001-11-01

    The maximum entropy method (MEM) is a powerful inverse analysis technique that is used in many fields of science and engineering to perform tasks such as image reconstruction and processing of nuclear magnetic resonance signals. Unlike other methods, MEM naturally incorporates a priori knowledge of the problem into the optimized cost function. This feature is especially important in radiotherapy planning, because some knowledge is usually available about the stage of tumor development and about the prescription doses, including some dose constraints to the surrounding normal organs. Inverse planning is inherently consistent with the ability of MEM to estimate parameters inversely. In this investigation, an entropy function determines the homogeneity of dose distribution in the planning target volume; a least-squares function is added to the maximum entropy function as a constraint to measure the quality of reconstructed doses in organs at risk; and an iterative Newton-Ralphson algorithm searches for the optimization solution. Here we provide two examples that validate this application of MEM and the results were compared with manual plans. Although the examples involve conformal radiotherapy, we think MEM can be adopted to optimize intensity-modulated radiation therapy. PMID:11764028

  14. Comparison of selected dose calculation algorithms in radiotherapy treatment planning for tissues with inhomogeneities

    NASA Astrophysics Data System (ADS)

    Woon, Y. L.; Heng, S. P.; Wong, J. H. D.; Ung, N. M.

    2016-03-01

    Inhomogeneity correction is recommended for accurate dose calculation in radiotherapy treatment planning since human body are highly inhomogeneous with the presence of bones and air cavities. However, each dose calculation algorithm has its own limitations. This study is to assess the accuracy of five algorithms that are currently implemented for treatment planning, including pencil beam convolution (PBC), superposition (SP), anisotropic analytical algorithm (AAA), Monte Carlo (MC) and Acuros XB (AXB). The calculated dose was compared with the measured dose using radiochromic film (Gafchromic EBT2) in inhomogeneous phantoms. In addition, the dosimetric impact of different algorithms on intensity modulated radiotherapy (IMRT) was studied for head and neck region. MC had the best agreement with the measured percentage depth dose (PDD) within the inhomogeneous region. This was followed by AXB, AAA, SP and PBC. For IMRT planning, MC algorithm is recommended for treatment planning in preference to PBC and SP. The MC and AXB algorithms were found to have better accuracy in terms of inhomogeneity correction and should be used for tumour volume within the proximity of inhomogeneous structures.

  15. Deformable Dose Reconstruction to Optimize the Planning and Delivery of Liver Cancer Radiotherapy

    NASA Astrophysics Data System (ADS)

    Velec, Michael

    The precise delivery of radiation to liver cancer patients results in improved control with higher tumor doses and minimized normal tissues doses. A margin of normal tissue around the tumor requires irradiation however to account for treatment delivery uncertainties. Daily image-guidance allows targeting of the liver, a surrogate for the tumor, to reduce geometric errors. However poor direct tumor visualization, anatomical deformation and breathing motion introduce uncertainties between the planned dose, calculated on a single pre-treatment computed tomography image, and the dose that is delivered. A novel deformable image registration algorithm based on tissue biomechanics was applied to previous liver cancer patients to track targets and surrounding organs during radiotherapy. Modeling these daily anatomic variations permitted dose accumulation, thereby improving calculations of the delivered doses. The accuracy of the algorithm to track dose was validated using imaging from a deformable, 3-dimensional dosimeter able to optically track absorbed dose. Reconstructing the delivered dose revealed that 70% of patients had substantial deviations from the initial planned dose. An alternative image-guidance technique using respiratory-correlated imaging was simulated, which reduced both the residual tumor targeting errors and the magnitude of the delivered dose deviations. A planning and delivery strategy for liver radiotherapy was then developed that minimizes the impact of breathing motion, and applied a margin to account for the impact of liver deformation during treatment. This margin is 38% smaller on average than the margin used clinically, and permitted an average dose-escalation to liver tumors of 9% for the same risk of toxicity. Simulating the delivered dose with deformable dose reconstruction demonstrated the plans with smaller margins were robust as 90% of patients' tumors received the intended dose. This strategy can be readily implemented with widely

  16. A technique using {sup 99m}Tc-mebrofenin SPECT for radiotherapy treatment planning for liver cancers or metastases

    SciTech Connect

    Shen, Sui; Jacob, Rojymon; Bender, Luvenia W.; Duan, Jun; Spencer, Sharon A.

    2014-04-01

    Radiotherapy or stereotactic body radiosurgery (SBRT) requires a sufficient functional liver volume to tolerate the treatment. The current study extended the work of de Graaf et al. (2010) [3] on the use of {sup 99m}Tc-mebrofenin imaging for presurgery planning to radiotherapy planning for liver cancer or metastases. Patient was immobilized and imaged in an identical position on a single-photon emission computed tomography/computed tomography (SPECT-CT) system and a radiotherapy simulation CT system. {sup 99m}Tc-mebrofenin SPECT was registered to the planning CT through image registration of noncontrast CT from SPECT-CT system to the radiotherapy planning CT. The voxels with higher uptake of {sup 99m}Tc-mebrofenin were transferred to the planning CT as an avoidance structure in optimizing a 2-arc RapidArc plan for SBRT delivery. Excellent dose coverage to the target and sparing of the healthy remnant liver volume was achieved. This report illustrated a procedure for the use of {sup 99m}Tc-mebrofenin SPECT for optimizing radiotherapy for liver cancers and metastases.

  17. Feasibility Study of Intensity-Modulated Radiotherapy (IMRT) Treatment Planning Using Brain Functional MRI

    SciTech Connect

    Chang Jenghwa Kowalski, Alex; Hou, Bob; Narayana, Ashwatha

    2008-04-01

    The purpose of this work was to study the feasibility of incorporating functional magnetic resonance imaging (fMRI) information for intensity modulated radiotherapy (IMRT) treatment planning of brain tumors. Three glioma patients were retrospectively replanned for radiotherapy (RT) with additional fMRI information. The fMRI of each patient was acquired using a bilateral finger-tapping paradigm with a gradient echo EPI (Echo Planer Imaging) sequence. The fMRI data were processed using the Analysis of Functional Neuroimaging (AFNI) software package for determining activation volumes, and the volumes were fused with the simulation computed tomography (CT) scan. The actived pixels in left and right primary motor cortexes (PMCs) were contoured as critical structures for IMRT planning. The goal of replanning was to minimize the RT dose to the activation volumes in the PMC regions, while maintaining a similar coverage to the planning target volume (PTV) and keeping critical structures within accepted dose tolerance. Dose-volume histograms of the treatment plans with and without considering the fMRI information were compared. Beam angles adjustment or additional beams were needed for 2 cases to meet the planning criteria. Mean dose to the contralateral and ipsilateral PMC was significantly reduced by 66% and 55%, respectively, for 1 patient. For the other 2 patients, mean dose to contralateral PMC region was lowered by 73% and 69%. In general, IMRT optimization can reduce the RT dose to the PMC regions without compromising the PTV coverage or sparing of other critical organs. In conclusion, it is feasible to incorporate the fMRI information into the RT treatment planning. IMRT planning allows a significant reduction in RT dose to the PMC regions, especially if the region does not lie within the PTV.

  18. Volumetric modulated arc therapy for hippocampal-sparing radiotherapy in transformed low-grade glioma: A treatment planning case report.

    PubMed

    Kazda, T; Pospisil, P; Vrzal, M; Sevela, O; Prochazka, T; Jancalek, R; Slampa, P; Laack, N N

    2015-05-01

    Timing of radiotherapy for low-grade gliomas is still controversial due to concerns of possible adverse late effects. Prevention of possible late cognitive sequelae by hippocampal avoidance has shown promise in phase II trials. A patient with progressive low-grade glioma with gradual dedifferentiation into anaplastic astrocytoma is presented along with description of radiotherapy planning process attempting to spare the hippocampus. To our knowledge, this is the first described case using volumetric modulated arc technique to spare hippocampus during transformed low-grade glioma radiotherapy. Using modern intensity-modulated radiotherapy systems it is possible to selectively spare hippocampus together with other standard organs at risk. For selected patients, an attempt to spare hippocampus can be considered as long as other dose characteristics are not significantly compromised compared to standard treatment plan created without any effort to avoid hippocampus. PMID:25835374

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

    SciTech Connect

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

    2014-04-15

    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

  20. A method for integrating computed tomography into radiotherapy planning and treatment.

    PubMed

    Ash, D V; Andrews, B; Stubbs, B

    1983-01-01

    A technique is described for accurate localisation and radiotherapy treatment planning for a wide range of intrathoracic, abdominal and pelvic tumours. It allows the patient to proceed in one step from a single examination by computed tomography (CT) to treatment and avoids the need for separate treatment simulation. Compatible laser-beam positioning systems between the CT scanner and treatment-machine rooms ensure accurate reproduction of patient position, so that CT data are directly applicable to treatment. The use of appropriate skin markers, which appear on the CT scan, allows accurate measurements of the distance of the centre of the planned volume from a tattoo placed on the patient at the time of the scan, and ensures that the planned treatment fields are accurately directed. PMID:6822045

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

    NASA Astrophysics Data System (ADS)

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

    2007-07-01

    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_RT, 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

  2. Challenges of radiotherapy: report on the 4D treatment planning workshop 2013.

    PubMed

    Knopf, Antje; Nill, Simeon; Yohannes, Indra; Graeff, Christian; Dowdell, Stephen; Kurz, Christopher; Sonke, Jan-Jakob; Biegun, Aleksandra K; Lang, Stephanie; McClelland, Jamie; Champion, Benjamin; Fast, Martin; Wölfelschneider, Jens; Gianoli, Chiara; Rucinski, Antoni; Baroni, Guido; Richter, Christian; van de Water, Steven; Grassberger, Clemens; Weber, Damien; Poulsen, Per; Shimizu, Shinichi; Bert, Christoph

    2014-11-01

    This report, compiled by experts on the treatment of mobile targets with advanced radiotherapy, summarizes the main conclusions and innovations achieved during the 4D treatment planning workshop 2013. This annual workshop focuses on research aiming to advance 4D radiotherapy treatments, including all critical aspects of time resolved delivery, such as in-room imaging, motion detection, motion managing, beam application, and quality assurance techniques. The report aims to revise achievements in the field and to discuss remaining challenges and potential solutions. As main achievements advances in the development of a standardized 4D phantom and in the area of 4D-treatment plan optimization were identified. Furthermore, it was noticed that MR imaging gains importance and high interest for sequential 4DCT/MR data sets was expressed, which represents a general trend of the field towards data covering a longer time period of motion. A new point of attention was work related to dose reconstructions, which may play a major role in verification of 4D treatment deliveries. The experimental validation of results achieved by 4D treatment planning and the systematic evaluation of different deformable image registration methods especially for inter-modality fusions were identified as major remaining challenges. A challenge that was also suggested as focus for future 4D workshops was the adaptation of image guidance approaches from conventional radiotherapy into particle therapy. Besides summarizing the last workshop, the authors also want to point out new evolving demands and give an outlook on the focus of the next workshop. PMID:25172392

  3. Detecting MLC errors in stereotactic radiotherapy plans with a liquid filled ionization chamber array.

    PubMed

    O'Connor, Patrick; Seshadri, Venkatakrisnan; Charles, Paul

    2016-03-01

    Quality assurance of stereotactic radiotherapy demands the use of equipment with the highest resolution and sensitivity available. This study examines the sensitivity of a commercially available liquid-filled ionization chamber array-the Octavius 1000 SRS (PTW, Frieburg, Germany) for detecting small (sub-millimetre) multi-leaf collimator (MLC) alignment errors in static square fields (side length 16-40 mm). Furthermore, the effectiveness of detecting small MLC errors in clinical stereotactic radiotherapy patient plans using the device was also evaluated. The commonly used gamma pass rate metric (of the measurements compared with treatment planning system generated results) was used. The gamma pass rates were then evaluated as a function of MLC position error (MLC error size 0.1-2.5 mm). The detector array exhibited a drop in pass rate between plans without error and those which had MLC errors induced. For example a drop in pass rate of 4.5 % (gamma criteria 3 %, 1 mm) was observed when a 0.8 mm error was introduced into a 16 mm square field. Furthermore the drop in pass rate increased as the MLC position error increased. This study showed that the Octavius 1000 SRS array could be a useful tool for applications requiring the detection of small geometric delivery uncertainties. PMID:26979835

  4. Retrospective estimate of the quality of intensity-modulated radiotherapy plans for lung cancer

    NASA Astrophysics Data System (ADS)

    Koo, Jihye; Yoon, Myonggeun; Chung, Weon Kuu; Kim, Dong Wook

    2015-07-01

    This study estimated the planning quality of intensity-modulated radiotherapy in 42 lung cancer cases to provide preliminary data for the development of a planning quality assurance algorithm. Organs in or near the thoracic cavity (ipsilateral lung, contralateral lung, heart, liver, esophagus, spinal cord, and bronchus) were selected as organs at risk (OARs). Radiotherapy plans were compared by using the conformity index (CI), coverage index (CVI), and homogeneity index (HI) of the planning target volume (PTV), the OAR-PTV distance and the OAR-PTV overlap volume, and the V10 Gy , V20 Gy , and equivalent uniform dose (EUD) of the OARs. The CI, CVI, and HI of the PTV were 0.54-0.89 (0.77 ± 0.08), 0.90-1.00 (0.98 ± 0.02), and 0.11-0.41, (0.15 ± 0.05), respectively. The mean EUDs (V10 Gy , V20 Gy ) of the ipsilateral lung, contralateral lung, esophagus, cord, liver, heart, and bronchus were 8.07 Gy (28.06, 13.17), 2.59 Gy (6.53, 1.18), 7.02 Gy (26.17, 12.32), 3.56 Gy (13.56, 4.48), 0.72 Gy (2.15, 0.91), 5.14 Gy (19.68, 8.62), and 10.56 Gy (36.08, 19.79), respectively. EUDs tended to decrease as the OAR-PTV distance increased and the OAR-PTV overlap volume decreased. Because the plans in this study were from a single department, relatively few people were involved in treatment planning. Differences in treatment results for a given patient would be much more pronounced if many departments were involved.

  5. Personnel radiation dose considerations in the use of an integrated PET-CT scanner for radiotherapy treatment planning.

    PubMed

    Carson, K J; Young, V A L; Cosgrove, V P; Jarritt, P H; Hounsell, A R

    2009-11-01

    The acquisition of radiotherapy planning scans on positron emission tomography (PET)-CT scanners requires the involvement of radiotherapy radiographers. This study assessed the radiation dose received by these radiographers during this process. Radiotherapy planning (18)F-fluorodeoxyglucose ((18)F-FDG) PET-CT scans were acquired for 28 non-small cell lung cancer patients. In order to minimise the radiation dose received, a two-stage process was used in which the most time-consuming part of the set-up was performed before the patient received their (18)F-FDG injection. Throughout this process, the radiographers wore electronic personal dosemeters and recorded the doses received at different stages of the process. The mean total radiation dose received by a radiotherapy radiographer was 5.1+/-2.6 microSv per patient. The use of the two-stage process reduced the time spent in close proximity to the patient by approximately a factor of four. The two-stage process was effective in keeping radiation dose to a minimum. The use of a pre-injection set-up session reduces the radiation dose to the radiotherapy radiographers because of their involvement in PET-CT radiotherapy treatment planning scans by approximately a factor of three. PMID:19332513

  6. Long-Term Results of a Prospective, Phase II Study of Long-Term Androgen Ablation, Pelvic Radiotherapy, Brachytherapy Boost, and Adjuvant Docetaxel in Patients With High-Risk Prostate Cancer

    SciTech Connect

    DiBiase, Steven J.; Hussain, Arif; Kataria, Ritesh; Amin, Pradip; Bassi, Sunakshi; Dawson, Nancy; Kwok, Young

    2011-11-01

    Purpose: We report the long-term results of a prospective, Phase II study of long-term androgen deprivation (AD), pelvic radiotherapy (EBRT), permanent transperineal prostate brachytherapy boost (PB), and adjuvant docetaxel in patients with high-risk prostate cancer. Methods and Materials: Eligibility included biopsy-proven prostate adenocarcinoma with the following: prostate-specific antigen (PSA) > 20 ng/ml; or Gleason score of 7 and a PSA >10 ng/ml; or any Gleason score of 8 to 10; or stage T2b to T3 irrespective of Gleason score or PSA. Treatment consisted of 45 Gy of pelvic EBRT, followed 1 month later by PB with either iodine-125 or Pd-103. One month after PB, patients received three cycles of docetaxel chemotherapy (35 mg/m{sup 2} per week, Days 1, 8, and 15 every 28 days). All patients received 2 years of AD. Biochemical failure was defined as per the Phoenix definition (PSA nadir + 2). Results: From August 2000 to March 2004, 42 patients were enrolled. The median overall and active follow-ups were 5.6 years (range, 0.9-7.8 years) and 6.3 years (range, 4-7.8 years), respectively. Grade 2 and 3 acute genitourinary (GU) and gastrointestinal (GI) toxicities were 50.0% and 14.2%, respectively, with no Grade 4 toxicities noted. Grade 3 and 4 acute hematologic toxicities were 19% and 2.4%, respectively. Of the patients, 85.7% were able to complete the planned multimodality treatment. The 5- and 7-year actuarial freedom from biochemical failures rates were 89.6% and 86.5%, and corresponding rates for disease-free survival were 76.2% and 70.4%, respectively. The 5- and 7-year actuarial overall survival rates were 83.3% and 80.1%, respectively. The 5- and 7-year actuarial rates of late Grade 2 GI/GU toxicity (no Grade 3-5) was 7.7%. Conclusions: The trimodality approach of using 2 years of AD, external radiation, brachytherapy, and upfront docetaxel in high-risk prostate cancer is well tolerated, produces encouraging long-term results, and should be validated in a

  7. A trichrome beam model for biological dose calculation in scanned carbon-ion radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Inaniwa, T.; Kanematsu, N.

    2015-01-01

    In scanned carbon-ion (C-ion) radiotherapy, some primary C-ions undergo nuclear reactions before reaching the target and the resulting particles deliver doses to regions at a significant distance from the central axis of the beam. The effects of these particles on physical dose distribution are accounted for in treatment planning by representing the transverse profile of the scanned C-ion beam as the superposition of three Gaussian distributions. In the calculation of biological dose distribution, however, the radiation quality of the scanned C-ion beam has been assumed to be uniform over its cross-section, taking the average value over the plane at a given depth (monochrome model). Since these particles, which have relatively low radiation quality, spread widely compared to the primary C-ions, the radiation quality of the beam should vary with radial distance from the central beam axis. To represent its transverse distribution, we propose a trichrome beam model in which primary C-ions, heavy fragments with atomic number Z ≥ 3, and light fragments with Z ≤ 2 are assigned to the first, second, and third Gaussian components, respectively. Assuming a realistic beam-delivery system, we performed computer simulations using Geant4 Monte Carlo code for analytical beam modeling of the monochrome and trichrome models. The analytical beam models were integrated into a treatment planning system for scanned C-ion radiotherapy. A target volume of 20  ×  20  ×  40 mm3 was defined within a water phantom. A uniform biological dose of 2.65 Gy (RBE) was planned for the target with the two beam models based on the microdosimetric kinetic model (MKM). The plans were recalculated with Geant4, and the recalculated biological dose distributions were compared with the planned distributions. The mean target dose of the recalculated distribution with the monochrome model was 2.72 Gy (RBE), while the dose with the trichrome model was 2.64 Gy (RBE). The monochrome model

  8. A self-adaptive case-based reasoning system for dose planning in prostate cancer radiotherapy

    SciTech Connect

    Mishra, Nishikant; Petrovic, Sanja; Sundar, Santhanam

    2011-12-15

    Purpose: Prostate cancer is the most common cancer in the male population. Radiotherapy is often used in the treatment for prostate cancer. In radiotherapy treatment, the oncologist makes a trade-off between the risk and benefit of the radiation, i.e., the task is to deliver a high dose to the prostate cancer cells and minimize side effects of the treatment. The aim of our research is to develop a software system that will assist the oncologist in planning new treatments. Methods: A nonlinear case-based reasoning system is developed to capture the expertise and experience of oncologists in treating previous patients. Importance (weights) of different clinical parameters in the dose planning is determined by the oncologist based on their past experience, and is highly subjective. The weights are usually fixed in the system. In this research, the weights are updated automatically each time after generating a treatment plan for a new patient using a group based simulated annealing approach. Results: The developed approach is analyzed on the real data set collected from the Nottingham University Hospitals NHS Trust, City Hospital Campus, UK. Extensive experiments show that the dose plan suggested by the proposed method is coherent with the dose plan prescribed by an experienced oncologist or even better. Conclusions: The developed case-based reasoning system enables the use of knowledge and experience gained by the oncologist in treating new patients. This system may play a vital role to assist the oncologist in making a better decision in less computational time; it utilizes the success rate of the previously treated patients and it can also be used in teaching and training processes.

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

    PubMed

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

    2004-04-01

    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

  10. Target Volume Delineation for Partial Breast Radiotherapy Planning: Clinical Characteristics Associated with Low Interobserver Concordance

    SciTech Connect

    Petersen, Ross P.; Truong, Pauline T. Kader, Hosam A.; Berthelet, Eric; Lee, Junella C.; Hilts, Michelle L.; Kader, Adam S.; Beckham, Wayne A.; Olivotto, Ivo A.

    2007-09-01

    Purpose: To examine variability in target volume delineation for partial breast radiotherapy planning and evaluate characteristics associated with low interobserver concordance. Methods and Materials: Thirty patients who underwent planning CT for adjuvant breast radiotherapy formed the study cohort. Using a standardized scale to score seroma clarity and consensus contouring guidelines, three radiation oncologists independently graded seroma clarity and delineated seroma volumes for each case. Seroma geometric center coordinates, maximum diameters in three axes, and volumes were recorded. Conformity index (CI), the ratio of overlapping volume and encompassing delineated volume, was calculated for each case. Cases with CI {<=}0.50 were analyzed to identify features associated with low concordance. Results: The median time from surgery to CT was 42.5 days. For geometric center coordinates, variations from the mean were 0.5-1.1 mm and standard deviations (SDs) were 0.5-1.8 mm. For maximum seroma dimensions, variations from the mean and SDs were predominantly <5 mm, with the largest SDs observed in the medial-lateral axis. The mean CI was 0.61 (range, 0.27-0.84). Five cases had CI {<=}0.50. Conformity index was significantly associated with seroma clarity (p < 0.001) and seroma volume (p < 0.002). Features associated with reduced concordance included tissue stranding from the surgical cavity, proximity to muscle, dense breast parenchyma, and benign calcifications that may be mistaken for surgical clips. Conclusion: Variability in seroma contouring occurred in three dimensions, with the largest variations in the medial-lateral axis. Awareness of clinical features associated with reduced concordance may be applied toward training staff and refining contouring guidelines for partial breast radiotherapy trials.

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

    NASA Astrophysics Data System (ADS)

    Lo, Ching-Jung; Yang, Pei-Ying; Chao, Tsi-Chian; Tu, Shu-Ju

    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.

  12. Effect of Radiotherapy Planning Complexity on Survival of Elderly Patients With Unresected Localized Lung Cancer

    SciTech Connect

    Park, Chang H.; Bonomi, Marcelo; Cesaretti, Jamie; Neugut, Alfred I.; Wisnivesky, Juan P.

    2011-11-01

    Purpose: To evaluate whether complex radiotherapy (RT) planning was associated with improved outcomes in a cohort of elderly patients with unresected Stage I-II non-small-cell lung cancer (NSCLC). Methods and Materials: Using the Surveillance, Epidemiology, and End Results registry linked to Medicare claims, we identified 1998 patients aged >65 years with histologically confirmed, unresected stage I-II NSCLC. Patients were classified into an intermediate or complex RT planning group using Medicare physician codes. To address potential selection bias, we used propensity score modeling. Survival of patients who received intermediate and complex simulation was compared using Cox regression models adjusting for propensity scores and in a stratified and matched analysis according to propensity scores. Results: Overall, 25% of patients received complex RT planning. Complex RT planning was associated with better overall (hazard ratio 0.84; 95% confidence interval, 0.75-0.95) and lung cancer-specific (hazard ratio 0.81; 95% confidence interval, 0.71-0.93) survival after controlling for propensity scores. Similarly, stratified and matched analyses showed better overall and lung cancer-specific survival of patients treated with complex RT planning. Conclusions: The use of complex RT planning is associated with improved survival among elderly patients with unresected Stage I-II NSCLC. These findings should be validated in prospective randomized controlled trials.

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

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions 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

  14. Effective Doses in Four-Dimensional Computed Tomography for Lung Radiotherapy Planning

    SciTech Connect

    Mori, Shinichiro Ko, Susumu; Ishii, Takayoshi; Nishizawa, Kanae

    2009-04-01

    The recent broad adoption of 4-D computed tomography (4DCT) scanning in radiotherapy has allowed the accurate determination of the target volume of tumors by minimizing image degradation caused by respiratory motion. Although the radiation exposure of the treatment beam is significantly greater than that of CT scans used for treatment planning, it is important to recognize and optimize the radiation exposure in 4DCT from the radiological protection point of view. Here, radiation exposure in 4DCT was measured with a 16 multidetector CT. Organ doses were measured using thermoluminescence radiation dosimeter chips inserted at respective anatomical sites of an anthropomorphic phantom. Results were compared with those with the helical CT scan mode. The effective dose measured for 4DCT was 24.7 mSv, approximately four times higher than that for helical CT. However, the increase in treatment accuracy afforded by 4DCT means its use in radiotherapy is inevitable. The patient exposure in the 4DCT could be of value by clarifying the advantage of the treatment planning using 4DCT.

  15. Concurrent multimodality image segmentation by active contours for radiotherapy treatment planning

    SciTech Connect

    El Naqa, Issam; Yang Deshan; Apte, Aditya; Khullar, Divya; Mutic, Sasa; Zheng Jie; Bradley, Jeffrey D.; Grigsby, Perry; Deasy, Joseph O.

    2007-12-15

    Multimodality imaging information is regularly used now in radiotherapy treatment planning for cancer patients. The authors are investigating methods to take advantage of all the imaging information available for joint target registration and segmentation, including multimodality images or multiple image sets from the same modality. In particular, the authors have developed variational methods based on multivalued level set deformable models for simultaneous 2D or 3D segmentation of multimodality images consisting of combinations of coregistered PET, CT, or MR data sets. The combined information is integrated to define the overall biophysical structure volume. The authors demonstrate the methods on three patient data sets, including a nonsmall cell lung cancer case with PET/CT, a cervix cancer case with PET/CT, and a prostate patient case with CT and MRI. CT, PET, and MR phantom data were also used for quantitative validation of the proposed multimodality segmentation approach. The corresponding Dice similarity coefficient (DSC) was 0.90{+-}0.02 (p<0.0001) with an estimated target volume error of 1.28{+-}1.23% volume. Preliminary results indicate that concurrent multimodality segmentation methods can provide a feasible and accurate framework for combining imaging data from different modalities and are potentially useful tools for the delineation of biophysical structure volumes in radiotherapy treatment planning.

  16. Influence of segment width on plan quality for volumetric modulated arc based stereotactic body radiotherapy

    PubMed Central

    Nithiyanantham, Karthikeyan; Kadirampatti Mani, Ganesh; Subramani, Vikraman; Karukkupalayam Palaniappan, Karrthick; Uthiran, Mohanraj; Vellengiri, Sennniandavar; Raju, Sambasivaselli; Supe, Sanjay S.; Kataria, Tejinder

    2014-01-01

    Aim To study the influence of segment width on plan quality for volumetric modulated arc based stereotactic body radiotherapy. Background The redundancy of modulation for regularly shaped small volume tumors results in creation of many small segments and an increase of monitor units, with a consequent prolongation of treatment and uncertainty in treatment delivery. Materials and methods Six cases each in lung, abdomen and liver were taken for the study. For each case, three VMAT SBRT plans were generated with different penalties on minimum segment width of 0.5, 1.0 and 1.5 cm. A comparison was made on the metrics of dose volume histogram, dosimetric indices, monitor units (MUs) and delivery accuracy. Results The mean reduction of total MUs when compared with 0.5 cm plan was observed as 12.7 ± 6.0% and 17.5 ± 7.2% for 1.0 cm and 1.5 cm of minimum segment width, respectively. The p value showed a significant degradation in dosimetric indices for 1.5 cm plans when compared with 0.5 cm and 1.0 cm plans. The average deviation of measured dose with TPS calculated was 3.0 ± 1.1%, 2.1 ± 0.84% and 1.8 ± 0.9% for 0.5, 1.0 and 1.5 cm, respectively. The calculated gamma index with pass criteria of 2% dose difference and 2 mm distance to agreement was 95.9 ± 2.8%, 96.5 ± 2.6% and 97.8 ± 1.6% as calculated for 0.5, 1.0 and 1.5 cm of penalties, respectively. In view of the trade off between delivery efficiency and plan quality, 1 cm minimum segment width plans showed an improvement. Conclusions VMAT SBRT plans with increased optimal value of minimum segment width showed better plan quality and delivery efficiency for stereotactic body radiotherapy. PMID:25184052

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

    SciTech Connect

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

    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.

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

    PubMed

    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. PMID:17943336

  19. Assessing the shift of radiobiological metrics in lung radiotherapy plans using 2D gamma index

    PubMed Central

    Balosso, Jacques

    2016-01-01

    Background The purpose of this work is to investigate the 2D gamma (γ) maps to illustrate the change of radiobiological outcomes for lung radiotherapy plans and evaluate the correlation between tumor control probability (TCP), normal tissue complication probability (NTCP) with γ passing rates (γ-rates). Methods Nine patients with lung cancer were used. The doses were calculated using Modified Batho method integrated with pencil beam convolution (MB-PBC) and anisotropic analytical algorithm (AAA) using the same beam arrangements and prescription dose. The TCP and NTCP were estimated, respectively, using equivalent uniform dose (EUD) model and Lyman-Kutcher-Burman (LKB) model. The correlation between ΔTCP or ΔNTCP with γ-rates, from 2%/2 and 3%/3 mm, were tested to explore the best correlation predicting the relevant γ criteria using Spearman’s rank test (ρ). Wilcoxon paired test was used to calculate P value. Results TCP value was significantly lower in the recalculated AAA plans as compared to MB plans. However, AAA predicted more NTCP on lung pneumonitis according to the LKB model and using relevant radiobiological parameters (n, m and TD50) for MB-PBC and AAA, with P=0.03. The data showed a weak correlation between radiobiological metrics with γ-rates or γ-mean, ρ<0.3. Conclusions AAA and MB yield different TCP values as well as NTCP for lung pneumonitis based on the LKB model parameters. Therefore, 2D γ-maps, generated with 2%/2 or 3%/3 mm, could illustrate visual information about the radiobiological changes. The information is useful to evaluate the clinical outcome of a radiotherapy treatment and to approve the treatment plan of the patient if the dose constraints are respected. On the other hand, the γ-maps tool can be used as quality assurance (QA) process to check the predicted TCP and NTCP from radiobiological models. PMID:27413708

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Lau, Wan-Yee; Kennedy, Andrew S.; Kim, Yun Hwan; Lai, Hee Kit; Lee, Rheun-Chuan; Leung, Thomas W.T.; Liu, Ching-Sheng; Salem, Riad; Sangro, Bruno; Shuter, Borys; Wang, Shih-Chang

    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.

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

    PubMed

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

    2010-09-01

    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

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

    SciTech Connect

    Kimura, Tomoki; Nishibuchi, Ikuno; Murakami, Yuji; Kenjo, Masahiro; Kaneyasu, Yuko; Nagata, Yasushi

    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.

  4. SU-E-T-148: Efficient Verification Method for Modulated Electron Radiotherapy Treatment Plans

    SciTech Connect

    Henzen, D; Chatelain, C; Manser, P; Frei, D; Volken, W; Joosten, A; Loessl, K; Aebersold, D M; Fix, M K; Neuenschwander, H

    2014-06-01

    Purpose: For shallow tumors, modulated electron radiotherapy (MERT) promises a reduction of dose to distal organs at risk. At our institution a framework was developed in order to create treatment plans for MERT employing both forward and inverse optimization. In this work, an efficient quality assurance (QA) process is established. Methods: Treatment plans for three different tumor sites were created using an inverse optimization. These plans consist of 6–12 segments and energies between 6 and 18 MeV. An already established QA process for photon IMRT plans is now extended to additionally handle MERT plans. First, the dose distributions are calculated in a homogenous water phantom. For this task a dedicated Monte Carlo (MC) framework for MERT is used. Second, the segments are applied on a stand-alone amorphous silicon electronic portal imaging device (EPID) using a source-to-surface distance of 70 cm. This device was calibrated for electron beams in a previous work. An in-house developed analysis software, is then utilized for comparisons and evaluation of the measured and calculated dose distributions. Results: For all three plans the calculated dose distributions agree well with the measured ones. Using a 2D gamma comparison (2% of dose max/2 mm and 10% dose threshold) passing rates >98% are achieved.The dose calculation for each plan on the water phantom, using voxels of 0.2×0.2×0.2 cm{sup 3}, takes at maximum 30 min on a single core Pentium 2.66 GHz system with 6 GB RAM, to reach a statistical uncertainty of 2% (1 std. dev.). Conclusion: An already established QA procedure for IMRT photon plans was applied for MERT. The dedicated MC framework and the use of EPID measurements allow an efficient QA procedure in a clinical environment. This work was supported by Varian Medical Systems.

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

    NASA Astrophysics Data System (ADS)

    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. Planning evaluation of radiotherapy for complex lung cancer cases using helical tomotherapy

    NASA Astrophysics Data System (ADS)

    Kron, Tomas; Grigorov, Grigor; Yu, Edward; Yartsev, Slav; Chen, Jeff Z.; Wong, Eugene; Rodrigues, George; Trenka, Kris; Coad, Terry; Bauman, Glenn; Van Dyk, Jake

    2004-08-01

    Lung cancer treatment is one of the most challenging fields in radiotherapy. The aim of the present study was to investigate what role helical tomotherapy (HT), a novel approach to the delivery of highly conformal dose distributions using intensity-modulated radiation fan beams, can play in difficult cases with large target volumes typical for many of these patients. Tomotherapy plans were developed for 15 patients with stage III inoperable non-small-cell lung cancer. While not necessarily clinically indicated, elective nodal irradiation was included for all cases to create the most challenging scenarios with large target volumes. A 2 cm margin was used around the gross tumour volume (GTV) to generate primary planning target volume (PTV2) and 1 cm margin around elective nodes for secondary planning target volume (PTV1) resulting in PTV1 volumes larger than 1000 cm3 in 13 of the 15 patients. Tomotherapy plans were created using an inverse treatment planning system (TomoTherapy Inc.) based on superposition/convolution dose calculation for a fan beam thickness of 25 mm and a pitch factor between 0.3 and 0.8. For comparison, plans were created using an intensity-modulated radiation therapy (IMRT) approach planned on a commercial treatment planning system (TheraplanPlus, Nucletron). Tomotherapy delivery times for the large target volumes were estimated to be between 4 and 19 min. Using a prescribed dose of 60 Gy to PTV2 and 46 Gy to PTV1, the mean lung dose was 23.8 ± 4.6 Gy. A 'dose quality factor' was introduced to correlate the plan outcome with patient specific parameters. A good correlation was found between the quality of the HT plans and the IMRT plans with HT being slightly better in most cases. The overlap between lung and PTV was found to be a good indicator of plan quality for HT. The mean lung dose was found to increase by approximately 0.9 Gy per percent overlap volume. Helical tomotherapy planning resulted in highly conformal dose distributions. It

  7. Small animal radiotherapy research platforms

    NASA Astrophysics Data System (ADS)

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-06-01

    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.

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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

  10. SU-C-17A-01: MRI-Based Radiotherapy Treatment Planning In Pelvis

    SciTech Connect

    Hsu, S; Cao, Y; Jolly, S; Balter, J

    2014-06-15

    Purpose: To support radiotherapy dose calculation, synthetic CT (MRCT) image volumes need to represent the electron density of tissues with sufficient accuracy. This study compares CT and MRCT for pelvic radiotherapy. Methods: CT and multi-contrast MRI acquired using T1- based Dixon, T2 TSE, and PETRA sequences were acquired on an IRBapproved protocol patient. A previously published method was used to create a MRCT image volume by applying fuzzy classification on T1- weighted and calculated water image volumes (air and fluid voxels were excluded using thresholds applied to PETRA and T2-weighted images). The correlation of pelvic bone intensity between CT and MRCT was investigated. Two treatment plans, based on CT and MRCT, were performed to mimic treatment for: (a) pelvic bone metastasis with a 16MV parallel beam arrangement, and (b) gynecological cancer with 6MV volumetric modulated arc therapy (VMAT) using two full arcs. The CT-calculated fluence maps were used to recalculate doses using the MRCT-derived density grid. The dose-volume histograms and dose distributions were compared. Results: Bone intensities in the MRCT volume correlated linearly with CT intensities up to 800 HU (containing 96% of the bone volume), and then decreased with CT intensity increase (4% volume). There was no significant difference in dose distributions between CT- and MRCTbased plans, except for the rectum and bladder, for which the V45 differed by 15% and 9%, respectively. These differences may be attributed to normal and visualized organ movement and volume variations between CT and MR scans. Conclusion: While MRCT had lower bone intensity in highly-dense bone, this did not cause significant dose deviations from CT due to its small percentage of volume. These results indicate that treatment planning using MRCT could generate comparable dose distributions to that using CT, and further demonstrate the feasibility of using MRI-alone to support Radiation Oncology workflow. NIH R01EB016079.

  11. Volumetric Modulated Arc Therapy Planning for Primary Prostate Cancer With Selective Intraprostatic Boost Determined by {sup 18}F-Choline PET/CT

    SciTech Connect

    Kuang, Yu; Wu, Lili; Hirata, Emily; Miyazaki, Kyle; Sato, Miles

    2015-04-01

    Purpose: This study evaluated expected tumor control and normal tissue toxicity for prostate volumetric modulated arc therapy (VMAT) with and without radiation boosts to an intraprostatically dominant lesion (IDL), defined by {sup 18}F-choline positron emission tomography/computed tomography (PET/CT). Methods and Materials: Thirty patients with localized prostate cancer underwent {sup 18}F-choline PET/CT before treatment. Two VMAT plans, plan{sub 79} {sub Gy} and plan{sub 100-105} {sub Gy}, were compared for each patient. The whole-prostate planning target volume (PTV{sub prostate}) prescription was 79 Gy in both plans, but plan{sub 100-105} {sub Gy} added simultaneous boost doses of 100 Gy and 105 Gy to the IDL, defined by 60% and 70% of maximum prostatic uptake on {sup 18}F-choline PET (IDL{sub suv60%} and IDL{sub suv70%}, respectively, with IDL{sub suv70%} nested inside IDL{sub suv60%} to potentially enhance tumor specificity of the maximum point dose). Plan evaluations included histopathological correspondence, isodose distributions, dose-volume histograms, tumor control probability (TCP), and normal tissue complication probability (NTCP). Results: Planning objectives and dose constraints proved feasible in 30 of 30 cases. Prostate sextant histopathology was available for 28 cases, confirming that IDL{sub suv60%} adequately covered all tumor-bearing prostate sextants in 27 cases and provided partial coverage in 1 case. Plan{sub 100-105} {sub Gy} had significantly higher TCP than plan{sub 79} {sub Gy} across all prostate regions for α/β ratios ranging from 1.5 Gy to 10 Gy (P<.001 for each case). There were no significant differences in bladder and femoral head NTCP between plans and slightly lower rectal NTCP (endpoint: grade ≥ 2 late toxicity or rectal bleeding) was found for plan{sub 100-105} {sub Gy}. Conclusions: VMAT can potentially increase the likelihood of tumor control in primary prostate cancer while observing normal tissue tolerances through

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:25387249

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

    PubMed Central

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

    2014-01-01

    Background 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. Methods 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. Results 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. Conclusions These generated organ geometries are realistic and statistically representative. PMID:25435856

  15. SU-E-P-48: Evaluation of Intensity Modulated Radiotherapy (IMRT) with Three Different Commercial Planning Systems for the Treatment of Cervical Cancer

    SciTech Connect

    Liu, D; Chi, Z; Yang, H; Miao, M; Jing, Z

    2015-06-15

    Purpose: To investigate the performances of three commercial treatment planning systems (TPS) for intensity modulated radiotherapy (IMRT) optimization regarding cervical cancer. Methods: For twenty cervical cancer patients, three IMRT plans were retrospectively re-planned: one with Pinnacle TPS,one with Oncentra TPS and on with Eclipse TPS. The total prescribed dose was 50.4 Gy delivered for PTV and 58.8 Gy for PTVnd by simultaneous integrated boost technique. The treatments were delivered using the Varian 23EX accelerator. All optimization schemes generated clinically acceptable plans. They were evaluated based on target coverage, homogeneity (HI) and conformity (CI). The organs at risk (OARs) were analyzed according to the percent volume under some doses and the maximum doses. The statistical method of the collected data of variance analysis was used to compare the difference among the quality of plans. Results: IMRT with Eclipse provided significant better HI, CI and all the parameters of PTV. However, the trend was not extension to the PTVnd, it was still significant better at mean dose, D50% and D98%, but plans with Oncentra showed significant better in the hight dosage volume, such as maximum dose and D2%. For the bladder wall, there were not notable difference among three groups, although Pinnacle and Oncentra systems provided a little lower dose sparing at V50Gy of bladder and rectal wall and V40Gy of bladder wall, respectively. V40Gy of rectal wall (p=0.037), small intestine (p=0.001 for V30Gy, p=0.010 for maximum dose) and V50Gy of right-femoral head (p=0.019) from Eclipse plans showed significant better than other groups. Conclusion: All SIB-IMRT plans were clinically acceptable which were generated by three commercial TPSs. The plans with Eclipse system showed advantages over the plans with Oncentra and Pinnacle system in the overwhelming majority of the dose coverage for targets and dose sparing of OARs in cervical cancer.

  16. Retroperitoneal Sarcoma (RPS) High Risk Gross Tumor Volume Boost (HR GTV Boost) Contour Delineation Agreement Among NRG Sarcoma Radiation and Surgical Oncologists

    PubMed Central

    Baldini, Elizabeth H.; Bosch, Walter; Kane, John M.; Abrams, Ross A.; Salerno, Kilian E.; Deville, Curtiland; Raut, Chandrajit P.; Petersen, Ivy A.; Chen, Yen-Lin; Mullen, John T.; Millikan, Keith W.; Karakousis, Giorgos; Kendrick, Michael L.; DeLaney, Thomas F.; Wang, Dian

    2015-01-01

    Purpose Curative intent management of retroperitoneal sarcoma (RPS) requires gross total resection. Preoperative radiotherapy (RT) often is used as an adjuvant to surgery, but recurrence rates remain high. To enhance RT efficacy with acceptable tolerance, there is interest in delivering “boost doses” of RT to high-risk areas of gross tumor volume (HR GTV) judged to be at risk for positive resection margins. We sought to evaluate variability in HR GTV boost target volume delineation among collaborating sarcoma radiation and surgical oncologist teams. Methods Radiation planning CT scans for three cases of RPS were distributed to seven paired radiation and surgical oncologist teams at six institutions. Teams contoured HR GTV boost volumes for each case. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results HRGTV boost volume contour agreement between the seven teams was “substantial” or “moderate” for all cases. Agreement was best on the torso wall posteriorly (abutting posterior chest abdominal wall) and medially (abutting ipsilateral para-vertebral space and great vessels). Contours varied more significantly abutting visceral organs due to differing surgical opinions regarding planned partial organ resection. Conclusions Agreement of RPS HRGTV boost volumes between sarcoma radiation and surgical oncologist teams was substantial to moderate. Differences were most striking in regions abutting visceral organs, highlighting the importance of collaboration between the radiation and surgical oncologist for “individualized” target delineation on the basis of areas deemed at risk and planned resection. PMID:26018727

  17. Experience-Based Quality Control of Clinical Intensity-Modulated Radiotherapy Planning

    SciTech Connect

    Moore, Kevin L.; Brame, R. Scott; Low, Daniel A.; Mutic, Sasa

    2011-10-01

    Purpose: To incorporate a quality control tool, according to previous planning experience and patient-specific anatomic information, into the intensity-modulated radiotherapy (IMRT) plan generation process and to determine whether the tool improved treatment plan quality. Methods and Materials: A retrospective study of 42 IMRT plans demonstrated a correlation between the fraction of organs at risk (OARs) overlapping the planning target volume and the mean dose. This yielded a model, predicted dose = prescription dose (0.2 + 0.8 [1 - exp(-3 overlapping planning target volume/volume of OAR)]), that predicted the achievable mean doses according to the planning target volume overlap/volume of OAR and the prescription dose. The model was incorporated into the planning process by way of a user-executable script that reported the predicted dose for any OAR. The script was introduced to clinicians engaged in IMRT planning and deployed thereafter. The script's effect was evaluated by tracking {delta} = (mean dose-predicted dose)/predicted dose, the fraction by which the mean dose exceeded the model. Results: All OARs under investigation (rectum and bladder in prostate cancer; parotid glands, esophagus, and larynx in head-and-neck cancer) exhibited both smaller {delta} and reduced variability after script implementation. These effects were substantial for the parotid glands, for which the previous {delta} = 0.28 {+-} 0.24 was reduced to {delta} = 0.13 {+-} 0.10. The clinical relevance was most evident in the subset of cases in which the parotid glands were potentially salvageable (predicted dose <30 Gy). Before script implementation, an average of 30.1 Gy was delivered to the salvageable cases, with an average predicted dose of 20.3 Gy. After implementation, an average of 18.7 Gy was delivered to salvageable cases, with an average predicted dose of 17.2 Gy. In the prostate cases, the rectum model excess was reduced from {delta} = 0.28 {+-} 0.20 to {delta} = 0.07 {+-} 0

  18. Effect of Acuros XB algorithm on monitor units for stereotactic body radiotherapy planning of lung cancer

    SciTech Connect

    Khan, Rao F. Villarreal-Barajas, Eduardo; Lau, Harold; Liu, Hong-Wei

    2014-04-01

    Stereotactic body radiotherapy (SBRT) is a curative regimen that uses hypofractionated radiation-absorbed dose to achieve a high degree of local control in early stage non–small cell lung cancer (NSCLC). In the presence of heterogeneities, the dose calculation for the lungs becomes challenging. We have evaluated the dosimetric effect of the recently introduced advanced dose-calculation algorithm, Acuros XB (AXB), for SBRT of NSCLC. A total of 97 patients with early-stage lung cancer who underwent SBRT at our cancer center during last 4 years were included. Initial clinical plans were created in Aria Eclipse version 8.9 or prior, using 6 to 10 fields with 6-MV beams, and dose was calculated using the anisotropic analytic algorithm (AAA) as implemented in Eclipse treatment planning system. The clinical plans were recalculated in Aria Eclipse 11.0.21 using both AAA and AXB algorithms. Both sets of plans were normalized to the same prescription point at the center of mass of the target. A secondary monitor unit (MU) calculation was performed using commercial program RadCalc for all of the fields. For the planning target volumes ranging from 19 to 375 cm{sup 3}, a comparison of MUs was performed for both set of algorithms on field and plan basis. In total, variation of MUs for 677 treatment fields was investigated in terms of equivalent depth and the equivalent square of the field. Overall, MUs required by AXB to deliver the prescribed dose are on an average 2% higher than AAA. Using a 2-tailed paired t-test, the MUs from the 2 algorithms were found to be significantly different (p < 0.001). The secondary independent MU calculator RadCalc underestimates the required MUs (on an average by 4% to 5%) in the lung relative to either of the 2 dose algorithms.

  19. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  20. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning.

    PubMed

    Thomas, T Hannah Mary; Devakumar, D; Purnima, S; Ravindran, B Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm x 10 cm beam at a gantry angle of 0 degrees and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between +/-6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible. PMID:19287087

  1. Overview of recent advances in treatment planning for ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Krämer, Michael; Scifoni, Emanuele; Schmitz, Frederike; Sokol, Olga; Durante, Marco

    2014-10-01

    To achieve practical calculations of dose delivery in ion beam radiotherapy, the physical models of beam propagation need to be properly implemented and supplemented by models describing the complex mechanisms of radiation damage in the biological tissues. TRiP98 is the first and most advanced treatment planning system for particles, in which physical and biological models have been incorporated to develop a clinically applicable tool for dose optimization and delivery. We report our recent advances in TRiP98 code development, in particular towards hypoxia-driven and multi-modal dose optimization. We also discuss the present needs and possible extensions of our models for which input from nanoscale physics is required. Contribution to the Topical Issue "Nano-scale Insights into Ion-beam Cancer Therapy", edited by Andrey V. Solov'yov, Nigel Mason, Paulo Limão-Vieira and Malgorzata Smialek-Telega.

  2. A matheuristic for the selection of beam directions and dose distribution in Radiotherapy Planning

    NASA Astrophysics Data System (ADS)

    Obal, T. M.; Florentino, H. O.; Gevert, V. G.; Jones, D. F.; Ouelhadj, D.; Volpi, N. M. P.; Wilhelm, V. E.

    2015-05-01

    In this paper a matheuristic using a combined Genetic Algorithm (GA) and exact method approach is proposed for selecting the position of the beams and dose distribution in Intensity Modulated Radiotherapy Planning (IMRT). GA selects a set of beams, for which the dose distribution is determined in the process of the GA's evaluation, using an optimisation model that is solved by an Interior Point method. Two instances are used to evaluate the performance of the matheuristic, comparing to the optimum solution, in terms of solution and computation time, found using the exact methodology of Branch and Bound. The results show that the matheuristic is appropriate to this problem in the case study proposed, as it is extremely faster than the exact method and also have reached the optimum solution in several experiments done.

  3. RapidArc radiotherapy planning for prostate cancer: Single-arc and double-arc techniques vs. intensity-modulated radiotherapy

    SciTech Connect

    Sze, Henry C.K.; Lee, Michael C.H.; Hung, Wai-Man; Yau, Tsz-Kok; Lee, Anne W.M.

    2012-04-01

    RapidArc is a novel technique using arc radiotherapy aiming to achieve intensity-modulated radiotherapy (IMRT)-quality radiotherapy plans with shorter treatment time. This study compared the dosimetric quality and treatment efficiency of single-arc (SA) vs. double-arc (DA) and IMRT in the treatment of prostate cancer. Fourteen patients were included in the analysis. The planning target volume (PTV), which contained the prostate gland and proximal seminal vesicles, received 76 Gy in 38 fractions. Seven-field IMRT, SA, and DA plans were generated for each patient. Dosimetric quality in terms of the minimum PTV dose, PTV hotspot, inhomogeneity, and conformity index; and sparing of rectum, bladder, and femoral heads as measured by V70, V-40, and V20 (% of volume receiving >70 Gy, 40 Gy, and 20 Gy, respectively), treatment efficiency as assessed by monitor units (MU) and treatment time were compared. All plan objectives were met satisfactorily by all techniques. DA achieved the best dosimetric quality with the highest minimum PTV dose, lowest hotspot, and the best homogeneity and conformity. It was also more efficient than IMRT. SA achieved the highest treatment efficiency with the lowest MU and shortest treatment time. The mean treatment time for a 2-Gy fraction was 4.80 min, 2.78 min, and 1.30 min for IMRT, DA, and SA, respectively. However, SA also resulted in the highest rectal dose. DA could improve target volume coverage and reduce treatment time and MU while maintaining equivalent normal tissue sparing when compared with IMRT. SA achieved the greatest treatment efficiency but with the highest rectal dose, which was nonetheless within tolerable limits. For busy units with high patient throughput, SA could be an acceptable option.

  4. Application of failure mode and effects analysis to treatment planning in scanned proton beam radiotherapy

    PubMed Central

    2013-01-01

    Background A multidisciplinary and multi-institutional working group applied the Failure Mode and Effects Analysis (FMEA) approach to the actively scanned proton beam radiotherapy process implemented at CNAO (Centro Nazionale di Adroterapia Oncologica), aiming at preventing accidental exposures to the patient. Methods FMEA was applied to the treatment planning stage and consisted of three steps: i) identification of the involved sub-processes; ii) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, iii) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results Thirty-four sub-processes were identified, twenty-two of them were judged to be potentially prone to one or more failure modes. A total of forty-four failure modes were recognized, 52% of them characterized by an RPN score equal to 80 or higher. The threshold of 125 for RPN was exceeded in five cases only. The most critical sub-process appeared related to the delineation and correction of artefacts in planning CT data. Failures associated to that sub-process were inaccurate delineation of the artefacts and incorrect proton stopping power assignment to body regions. Other significant failure modes consisted of an outdated representation of the patient anatomy, an improper selection of beam direction and of the physical beam model or dose calculation grid. The main effects of these failures were represented by wrong dose distribution (i.e. deviating from the planned one) delivered to the patient. Additional strategies for risk mitigation, easily and immediately applicable, consisted of a systematic information collection about any known implanted prosthesis directly from each patient and enforcing a short interval time between CT scan and treatment start. Moreover, (i) the investigation of

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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 continuous

  6. Intensity-modulated radiotherapy (IMRT) for carcinoma of the maxillary sinus: A comparison of IMRT planning systems

    SciTech Connect

    Ahmed, Raef S. . E-mail: Rahmed@uabmc.edu; Ove, Roger; Duan, Jun; Popple, Richard; Cobb, Glenn

    2006-10-01

    The treatment of maxillary sinus carcinoma with forward planning can be technically difficult when the neck also requires radiotherapy. This difficulty arises because of the need to spare the contralateral face while treating the bilateral neck. There is considerable potential for error in clinical setup and treatment delivery. We evaluated intensity-modulated radiotherapy (IMRT) as an improvement on forward planning, and compared several inverse planning IMRT platforms. A composite dose-volume histogram (DVH) was generated from a complex forward planned case. We compared the results with those generated by sliding window fixed field dynamic multileaf collimator (MLC) IMRT, using sets of coplanar beams. All setups included an anterior posterior (AP) beam, and 3-, 5-, 7-, and 9-field configurations were evaluated. The dose prescription and objective function priorities were invariant. We also evaluated 2 commercial tomotherapy IMRT delivery platforms. DVH results from all of the IMRT approaches compared favorably with the forward plan. Results for the various inverse planning approaches varied considerably across platforms, despite an attempt to prescribe the therapy similarly. The improvement seen with the addition of beams in the fixed beam sliding window case was modest. IMRT is an effective means of delivering radiotherapy reliably in the complex setting of maxillary sinus carcinoma with neck irradiation. Differences in objective function definition and optimization algorithms can lead to unexpected differences in the final dose distribution, and our evaluation suggests that these factors are more significant than the beam arrangement or number of beams.

  7. Comparison of inverse-planned three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for non-small-cell lung cancer

    SciTech Connect

    Christian, Judith A. . E-mail: judith.christian@nuh.nhs.uk; Bedford, James L.; Webb, Steve; Brada, Michael

    2007-03-01

    Purpose: Lungs are the major dose-limiting organ during radiotherapy (RT) for non-small-cell lung cancer owing to the development of pneumonitis. This study compared intensity-modulated RT (IMRT) with three-dimensional conformal RT (3D-CRT) in reducing the dose to the lungs. Methods: Ten patients with localized non-small-cell lung cancer underwent computed tomography (CT). The planning target volume (PTV) was defined and the organs at risk were outlined. An inverse-planning program, AutoPlan, was used to design the beam angle-optimized six-field noncoplanar 3D-CRT plans. Each 3D-CRT plan was compared with a series of five IMRT plans per patient. The IMRT plans were created using a commercial algorithm and consisted of a series of three, five, seven, and nine equidistant coplanar field arrangements and one six-field noncoplanar plan. The planning objectives were to minimize the lung dose while maintaining the dose to the PTV. The percentage of lung volume receiving >20 Gy (V{sub 20}) and the percentage of the PTV covered by the 90% isodose (PTV{sub 90}) were the primary endpoints. The PTV{sub 90}/V{sub 20} ratio was used as the parameter accounting for both the reduction in lung volume treated and the PTV coverage. Results: All IMRT plans, except for the three-field coplanar plans, improved the PTV{sub 90}/V{sub 20} ratio significantly compared with the optimized 3D-CRT plan. Nine coplanar IMRT beams were significantly better than five or seven coplanar IMRT beams, with an improved PTV{sub 90}/V{sub 20} ratio. Conclusion: The results of our study have shown that IMRT can reduce the dose to the lungs compared with 3D-CRT by improving the conformity of the plan.

  8. Tally and geometry definition influence on the computing time in radiotherapy treatment planning with MCNP Monte Carlo code.

    PubMed

    Juste, B; Miro, R; Gallardo, S; Santos, A; Verdu, G

    2006-01-01

    The present work has simulated the photon and electron transport in a Theratron 780 (MDS Nordion) (60)Co radiotherapy unit, using the Monte Carlo transport code, MCNP (Monte Carlo N-Particle), version 5. In order to become computationally more efficient in view of taking part in the practical field of radiotherapy treatment planning, this work is focused mainly on the analysis of dose results and on the required computing time of different tallies applied in the model to speed up calculations. PMID:17946330

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

    SciTech Connect

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

    2015-10-15

    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

  10. Dosimetric impact of image artifact from a wide-bore CT scanner in radiotherapy treatment planning

    SciTech Connect

    Wu, Vincent; Podgorsak, Matthew B.; Tran, Tuan-Anh; Malhotra, Harish K.; Wang, Iris Z.

    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

  11. Reduction in Radiation-Induced Morbidity by Use of an Intercurrent Boost in the Management of Early-Stage Breast Cancer

    SciTech Connect

    Trombetta, Mark; Julian, Thomas B.; Valakh, Vladimir; Greenberg, Larisa; Labban, George; Khalid, Mian K.; Werts, E. Day; Parda, David

    2010-08-01

    Purpose: Electron or photon boost immediately following whole-breast irradiation performed after conservation surgery for early-stage breast cancer is the accepted standard of care. This regimen frequently results in Grade III dermatitis, causing discomfort or treatment interruption. Herein, we compare patients treated with whole-breast irradiation followed by boost compared with a cohort with a planned intercurrent radiation boost. Methods and Materials: The records of 650 consecutive breast cancer patients treated at Allegheny General Hospital (AGH) between 2000 and 2008 were reviewed. Selected for this study were 327 patients with T1 or T2 tumors treated with external beam radiotherapy postlumpectomy. One hundred and sixty-nine patients were treated by whole-breast radiotherapy (WBRT) followed by boost at completion. One hundred fifty-eight were treated with a planned intercurrent boost (delivered following 3,600 cGy WBRT). The mean whole breast radiation dose in the conventionally treated group was 5,032 cGy (range, 4500-5400 cGy), and the mean whole breast dose was 5,097 cGy (range, 4860-5040 cGy) in the group treated with a planned intercurrent boost. Results: The occurrence of Grade III dermatitis was significantly reduced in the WBRT/intercurrent boost group compared with the WBRT/boost group (0.6% vs. 8.9%), as was the incidence of treatment interruption (1.9% vs. 14.2%). With a median follow-up of 32 months and 27 months, respectively, no significant difference in local control was identified. Conclusions: Patients treated with intercurrent boost developed less Grade III dermatitis and unplanned treatment interruptions with similar local control.

  12. A Treatment Planning Study of Stereotactic Body Radiotherapy for Atrial Fibrillation

    PubMed Central

    Kotecha, Rupesh; Sharma, Naveen; Andrews, Martin; Stephans, Kevin L; Oberti, Carlos; Lin, Sara; Wazni, Oussama; Tchou, Patrick; Saliba, Walid I; Suh, John

    2016-01-01

    Purpose: To explore the feasibility of using stereotactic body radiotherapy (SBRT) to irradiate the antra of the four pulmonary veins while protecting nearby critical organs, such as the esophagus. Materials and Methods: Twenty patients who underwent radiofrequency catheter ablation for atrial fibrillation were selected. For each patient, the antra of the four pulmonary veins were identified as the target volumes on a pre-catheterization contrast or non-contrast CT scan. On each CT scan, the esophagus, trachea, heart, and total lung were delineated and the esophagus was identified as the critical organ. For each patient, three treatment plans were designed with 0, 2, and 5 mm planning margins around the targets while avoiding overlap with a planning organ at risk volume (PRV) generated by a 2 mm expansion of the esophagus. Using three non-coplanar volumetric modulated arcs (VMAT), 60 plans were created to deliver a prescription dose of 50 Gy in five fractions, following the SBRT dose regimen for central lung tumors. With greater than 97% of the planning target volumes (PTV) receiving the prescription doses, we examined dosimetry to 0.03 cc and 5 cc of the esophagus PRV volume as well as other contoured structures. Results: The average PTV-0 mm, PTV-2 mm, and PTV-5 mm volumes were 3.05 ± 1.90 cc, 14.70 ± 5.00 cc, and 40.85 ± 10.20 cc, respectively. With three non-coplanar VMAT arcs, the average conformality indices (ratio of prescription isodose volume to the PTV volume) for the PTV-0 mm, PTV-2 mm and PTV-5 mm were 4.81 ± 2.0, 1.71 ± 0.19, and 1.23 ± 0.08, respectively. Assuming patients were treated under breath-hold with 2 mm planning margins to account for cardiac motion, all plans met esophageal PRV maximum dose limits < 50 Gy to 0.03 cc and 16 plans (80%) met < 27.5 Gy to 5 cc of the esophageal PRVs. For PTV-5 mm plans, 18 plans met the maximum dose limit < 50 Gy to 0.03 cc and only two plans met the maximum dose limit < 27.5 Gy to 5 cc of the

  13. Development of a new multi-modal Monte-Carlo radiotherapy planning system.

    PubMed

    Kumada, H; Nakamura, T; Komeda, M; Matsumura, A

    2009-07-01

    A new multi-modal Monte-Carlo radiotherapy planning system (developing code: JCDS-FX) is under development at Japan Atomic Energy Agency. This system builds on fundamental technologies of JCDS applied to actual boron neutron capture therapy (BNCT) trials in JRR-4. One of features of the JCDS-FX is that PHITS has been applied to particle transport calculation. PHITS is a multi-purpose particle Monte-Carlo transport code. Hence application of PHITS enables to evaluate total doses given to a patient by a combined modality therapy. Moreover, JCDS-FX with PHITS can be used for the study of accelerator based BNCT. To verify calculation accuracy of the JCDS-FX, dose evaluations for neutron irradiation of a cylindrical water phantom and for an actual clinical trial were performed, then the results were compared with calculations by JCDS with MCNP. The verification results demonstrated that JCDS-FX is applicable to BNCT treatment planning in practical use. PMID:19394839

  14. Impact of the accuracy of automatic tumour functional volume delineation on radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Le Maitre, Amandine; Hatt, Mathieu; Pradier, Olivier; Cheze-le Rest, Catherine; Visvikis, Dimitris

    2012-09-01

    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&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 (V95, D95, 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.

  15. Investigation of MR image distortion for radiotherapy treatment planning of prostate cancer

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Ma, C.-M.; Paskalev, K.; Li, J.; Yang, J.; Richardson, T.; Palacio, L.; Xu, X.; Chen, L.

    2006-03-01

    MR imaging based treatment planning for radiotherapy of prostate cancer is limited due to MR imaging system related geometrical distortions, especially for patients with large body sizes. On our 0.23 T open scanner equipped with the gradient distortion correction (GDC) software, the residual image distortions after the GDC were <5 mm within the central 36 cm × 36 cm area for a standard 48 cm field of view (FOV). In order to use MR imaging alone for treatment planning the effect of residual MR distortions on external patient contour determination, especially for the peripheral regions outside the 36 cm × 36 cm area, must be investigated and corrected. In this work, we performed phantom measurements to quantify MR system related residual geometric distortions after the GDC and the effective FOV. Our results show that for patients with larger lateral dimensions (>36 cm), the differences in patient external contours between distortion-free CT images and GDC-corrected MR images were 1-2 cm because of the combination of greater gradient distortion and loss of field homogeneity away from the isocentre and the uncertainties in patient setup during CT and MRI scans. The measured distortion maps were used to perform point-by-point corrections for patients with large dimensions inside the effective FOV. Using the point-by-point method, the geometrical distortion after the GDC were reduced to <3 mm for external contour determination and the effective FOV was expanded from 36 cm to 42 cm.

  16. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning.

    PubMed

    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

  17. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning

    SciTech Connect

    Wu, Vincent W.C.; Tse, Teddy K.H.; Ho, Cola L.M.; Yeung, Eric C.Y.

    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.

  18. Improving radiotherapy planning, delivery accuracy, and normal tissue sparing using cutting edge technologies

    PubMed Central

    Glide-Hurst, Carri K.

    2014-01-01

    In the United States, more than half of all new invasive cancers diagnosed are non-small cell lung cancer, with a significant number of these cases presenting at locally advanced stages, resulting in about one-third of all cancer deaths. While the advent of stereotactic ablative radiation therapy (SABR, also known as stereotactic body radiotherapy, or SBRT) for early-staged patients has improved local tumor control to >90%, survival results for locally advanced stage lung cancer remain grim. Significant challenges exist in lung cancer radiation therapy including tumor motion, accurate dose calculation in low density media, limiting dose to nearby organs at risk, and changing anatomy over the treatment course. However, many recent technological advancements have been introduced that can meet these challenges, including four-dimensional computed tomography (4DCT) and volumetric cone-beam computed tomography (CBCT) to enable more accurate target definition and precise tumor localization during radiation, respectively. In addition, advances in dose calculation algorithms have allowed for more accurate dosimetry in heterogeneous media, and intensity modulated and arc delivery techniques can help spare organs at risk. New delivery approaches, such as tumor tracking and gating, offer additional potential for further reducing target margins. Image-guided adaptive radiation therapy (IGART) introduces the potential for individualized plan adaptation based on imaging feedback, including bulky residual disease, tumor progression, and physiological changes that occur during the treatment course. This review provides an overview of the current state of the art technology for lung cancer volume definition, treatment planning, localization, and treatment plan adaptation. PMID:24688775

  19. 3D Ultrasound Can Contribute to Planning CT to Define the Target for Partial Breast Radiotherapy

    SciTech Connect

    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.

    2009-02-01

    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.

  20. 4D tumor centroid tracking using orthogonal 2D dynamic MRI: Implications for radiotherapy planning

    SciTech Connect

    Tryggestad, Erik; Flammang, Aaron; Shea, Steven M.; Hales, Russell; Herman, Joseph; Lee, Junghoon; McNutt, Todd; Roland, Teboh; Wong, John

    2013-09-15

    Purpose: Current pretreatment, 4D imaging techniques are suboptimal in that they sample breathing motion over a very limited “snapshot” in time. Heretofore, long-duration, 4D motion characterization for radiotherapy planning, margin optimization, and validation have been impractical for safety reasons, requiring invasive markers imaged under x-ray fluoroscopy. To characterize 3D tumor motion and associated variability over durations more consistent with treatments, the authors have developed a practical dynamic MRI (dMRI) technique employing two orthogonal planes acquired in a continuous, interleaved fashion.Methods: 2D balanced steady-state free precession MRI was acquired continuously over 9–14 min at approximately 4 Hz in three healthy volunteers using a commercial 1.5 T system; alternating orthogonal imaging planes (sagittal, coronal, sagittal, etc.) were employed. The 2D in-plane pixel resolution was 2 × 2 mm{sup 2} with a 5 mm slice profile. Simultaneous with image acquisition, the authors monitored a 1D surrogate respiratory signal using a device available with the MRI system. 2D template matching-based anatomic feature registration, or tracking, was performed independently in each orientation. 4D feature tracking at the raw frame rate was derived using spline interpolation.Results: Tracking vascular features in the lung for two volunteers and pancreatic features in one volunteer, the authors have successfully demonstrated this method. Registration error, defined here as the difference between the sagittal and coronal tracking result in the SI direction, ranged from 0.7 to 1.6 mm (1σ) which was less than the acquired image resolution. Although the healthy volunteers were instructed to relax and breathe normally, significantly variable respiration was observed. To demonstrate potential applications of this technique, the authors subsequently explored the intrafraction stability of hypothetical tumoral internal target volumes and 3D spatial probability

  1. A method for deriving a 4D-interpolated balanced planning target for mobile tumor radiotherapy

    SciTech Connect

    Roland, Teboh; Hales, Russell; McNutt, Todd; Wong, John; Simari, Patricio; Tryggestad, Erik

    2012-01-15

    Purpose: Tumor control and normal tissue toxicity are strongly correlated to the tumor and normal tissue volumes receiving high prescribed dose levels in the course of radiotherapy. Planning target definition is, therefore, crucial to ensure favorable clinical outcomes. This is especially important for stereotactic body radiation therapy of lung cancers, characterized by high fractional doses and steep dose gradients. The shift in recent years from population-based to patient-specific treatment margins, as facilitated by the emergence of 4D medical imaging capabilities, is a major improvement. The commonly used motion-encompassing, or internal-target volume (ITV), target definition approach provides a high likelihood of coverage for the mobile tumor but inevitably exposes healthy tissue to high prescribed dose levels. The goal of this work was to generate an interpolated balanced planning target that takes into account both tumor coverage and normal tissue sparing from high prescribed dose levels, thereby improving on the ITV approach. Methods: For each 4DCT dataset, 4D deformable image registration was used to derive two bounding targets, namely, a 4D-intersection and a 4D-composite target which minimized normal tissue exposure to high prescribed dose levels and maximized tumor coverage, respectively. Through definition of an ''effective overlap volume histogram'' the authors derived an ''interpolated balanced planning target'' intended to balance normal tissue sparing from prescribed doses with tumor coverage. To demonstrate the dosimetric efficacy of the interpolated balanced planning target, the authors performed 4D treatment planning based on deformable image registration of 4D-CT data for five previously treated lung cancer patients. Two 4D plans were generated per patient, one based on the interpolated balanced planning target and the other based on the conventional ITV target. Plans were compared for tumor coverage and the degree of normal tissue sparing

  2. 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.

    PubMed

    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. PMID:27084705

  3. [{sup 18}FDG] PET-CT-Based Intensity-Modulated Radiotherapy Treatment Planning of Head and Neck Cancer

    SciTech Connect

    El-Bassiouni, Mazen; Ciernik, I. Frank Davis, J. Bernard; El-Attar, Inas; Reiner, Beatrice; Burger, Cyrill; Goerres, Gerhard W.; Studer, Gabriela M.

    2007-09-01

    Purpose: To define the best threshold for tumor volume delineation of the (18) fluoro-2-deoxy-glucose positron emission tomography ({sup 18}FDG-PET) signal for radiotherapy treatment planning of intensity-modulated radiotherapy (IMRT) in head and neck cancer. Methods and Materials: In 25 patients with head-and-neck cancer, CT-based gross tumor volume (GTV{sub CT}) was delineated. After PET-CT image fusion, window level (L) was adapted to best fit the GTV{sub CT}, and GTV{sub PET} was delineated. Tumor maximum (S) and background uptake (B) were measured, and the threshold of the background-subtracted tumor maximum uptake (THR) was used for PET signal segmentation. Gross tumor volumes were expanded to planning target volumes (PTVs) and analyzed. Results: The mean value of S was 40 kBq/mL, S/B ratio was 16, and THR was 26%. The THR correlated with S (r = -0.752), but no correlation between THR and the S/B ratio was seen (r = -0.382). In 77% of cases, S was >30 kBq/mL, and in 23% it was {<=}30 kBq/mL, with a mean THR of 21.4% and 41.6%, respectively (p < 0.001). Using PTV{sub PET} in radiotherapy treatment planning resulted in a reduced PTV in 72% of cases, while covering 88.2% of GTV{sub CT}, comparable to the percentage of GTV{sub PET} covered by PTV{sub CT} (p = 0.15). Conclusions: A case-specific PET signal threshold is optimal in PET-based radiotherapy treatment planning. Signal gating using a THR of 20% in tumors with S >30% {+-} 1.6% kBq/mL and 40% in tumors with S {<=}30% {+-} 1.6% kBq/mL is suitable.

  4. American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: quality assurance for clinical radiotherapy treatment planning.

    PubMed

    Fraass, B; Doppke, K; Hunt, M; Kutcher, G; Starkschall, G; Stern, R; Van Dyke, J

    1998-10-01

    In recent years, the sophistication and complexity of clinical treatment planning and treatment planning systems has increased significantly, particularly including three-dimensional (3D) treatment planning systems, and the use of conformal treatment planning and delivery techniques. This has led to the need for a comprehensive set of quality assurance (QA) guidelines that can be applied to clinical treatment planning. This document is the report of Task Group 53 of the Radiation Therapy Committee of the American Association of Physicists in Medicine. The purpose of this report is to guide and assist the clinical medical physicist in developing and implementing a comprehensive but viable program of quality assurance for modern radiotherapy treatment planning. The scope of the QA needs for treatment planning is quite broad, encompassing image-based definition of patient anatomy, 3D beam descriptions for complex beams including multileaf collimator apertures, 3D dose calculation algorithms, and complex plan evaluation tools including dose volume histograms. The Task Group recommends an organizational framework for the task of creating a QA program which is individualized to the needs of each institution and addresses the issues of acceptance testing, commissioning the planning system and planning process, routine quality assurance, and ongoing QA of the planning process. This report, while not prescribing specific QA tests, provides the framework and guidance to allow radiation oncology physicists to design comprehensive and practical treatment planning QA programs for their clinics. PMID:9800687

  5. SU-E-J-137: Incorporating Tumor Regression Into Robust Plan Optimization for Head and Neck Radiotherapy

    SciTech Connect

    Zhang, P; Hu, J; Tyagi, N; Mageras, G; Lee, N; Hunt, M

    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

  6. Conformal 3D planned radiotherapy for pelvic lymphoceles following surgery for urological cancer: A case study

    PubMed Central

    Janssen, Stefan; Käsmann, Lukas; Cegla, Robert; Rades, Dirk

    2016-01-01

    The aim of the present study was to evaluate the outcome and toxicity of 3D conformal radiotherapy (RT) for persistent lymphoceles following surgery for urological cancer. A total of 6 patients with bladder (n=1) and prostate cancer (n=5), with persistent lymphoceles following surgery for a primary tumor were treated with total doses of 10–12 Gy (1 Gy single dose) after computed tomography (CT) based 3D planning in order to suspend secretion. No acute or chronic toxicities were observed. In 5 patients, secretion of lymph fluid resolved after RT and in 1 patient RT had no effect. After a mean follow-up of 21 months (range, 5–47 months), no patient suffered from any symptoms concerning his former lymphoceles. This is the first analysis, to the best of our knowledge, to evaluate a homogenous patient collective of urological cancer patients with persistent lymphoceles after surgery for the initial tumor. RT to lymphoceles in urological cancer patient is effective, very well-tolerated and should be offered to patients with persistent secretion following drainage.

  7. A novel four-dimensional radiotherapy method for lung cancer: imaging, treatment planning and delivery

    NASA Astrophysics Data System (ADS)

    Alasti, H.; Cho, Y. B.; Vandermeer, A. D.; Abbas, A.; Norrlinger, B.; Shubbar, S.; Bezjak, A.

    2006-06-01

    We present treatment planning methods based on four-dimensional computed tomography (4D-CT) to incorporate tumour motion using (1) a static field and (2) a dynamic field. Static 4D fields are determined to include the target in all breathing phases, whereas dynamic 4D fields are determined to follow the shape of the tumour assessed from 4D-CT images with a dynamic weighting factor. The weighting factor selection depends on the reliability of patient breathing and limitations of the delivery system. The static 4D method is compared with our standard protocol for gross tumour volume (GTV) coverage, mean lung dose and V20. It was found that the GTV delineated on helical CT without incorporating breathing motion does not adequately represent the target compared to the GTV delineated from 4D-CT. Dosimetric analysis indicates that the static 4D-CT based technique results in a reduction of the mean lung dose compared with the standard protocol. Measurements on a moving phantom and simulations indicated that 4D radiotherapy (4D-RT) synchronized with respiration-induced motion further reduces mean lung dose and V20, and may allow safe application of dose escalation and CRT/IMRT. The motions of the chest cavity, tumour and thoracic structures of 24 lung cancer patients are also analysed.

  8. Gemstone spectral imaging: determination of CT to ED conversion curves for radiotherapy treatment planning.

    PubMed

    Yagi, Masashi; Ueguchi, Takashi; Koizumi, Masahiko; Ogata, Toshiyuki; Yamada, Sachiko; Takahashi, Yutaka; Sumida, Iori; Akino, Yuichi; Konishi, Koji; Isohashi, Fumiaki; Tomiyama, Noriyuki; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2013-01-01

    The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the monochromatic image might be applied to radiotherapy treatment planning (RTP) to calculate dose distribution more accurately. Our goal here was to provide CT to electron density (ED) conversion curves with monochromatic images for RTP. Therefore, we assessed the reproducibility of CT numbers, an important factor on quality assurance, over short and long time periods for different substances at varying energy. CT number difference between measured and theoretical value was investigated. The scanner provided sufficient reproducibility of CT numbers for dose calculation over short and long time periods. The CT numbers of monochromatic images produced by this scanner had reasonable values for dose calculation. The CT to ED conversion curve becomes linear with respect to the relationship between CT numbers and EDs as the energy increases. We conclude that monochromatic imaging from a fast switching system can be applied for the dose calculation, keeping Hounsfield units (HU) stability. PMID:24036870

  9. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

    PubMed Central

    Alves, G.G.; Kinoshita, A.; de Oliveira, H.F.; 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. PMID:26017344

  10. The feasibility of atlas-based automatic segmentation of MRI for H&N radiotherapy planning.

    PubMed

    Wardman, Kieran; Prestwich, Robin J D; Gooding, Mark J; Speight, Richard J

    2016-01-01

    Atlas-based autosegmentation is an established tool for segmenting structures for CT-planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI-based, atlas-based autosegmentation for organs at risk (OAR) and lymph node levels, and to compare the segmentation accuracy with CT-based autosegmentation. Fourteen patients with locally advanced head and neck cancer in a prospective imaging study underwent a T1-weighted MRI and a PET-CT (with dedicated contrast-enhanced CT) in an immobilization mask. Organs at risk (orbits, parotids, brainstem, and spinal cord) and the left level II lymph node region were manually delineated on the CT and MRI separately. A 'leave one out' approach was used to automatically segment structures onto the remaining images separately for CT and MRI. Contour comparison was performed using multiple positional metrics: Dice index, mean distance to conformity (MDC), sensitivity index (Se Idx), and inclusion index (Incl Idx). Automatic segmentation using MRI of orbits, parotids, brainstem, and lymph node level was acceptable with a DICE coefficient of 0.73-0.91, MDC 2.0-5.1mm, Se Idx 0.64-0.93, Incl Idx 0.76-0.93. Segmentation of the spinal cord was poor (Dice coefficient 0.37). The process of automatic segmentation was significantly better on MRI compared to CT for orbits, parotid glands, brainstem, and left lymph node level II by multiple positional metrics; spinal cord segmentation based on MRI was inferior compared with CT. Accurate atlas-based automatic segmentation of OAR and lymph node levels is feasible using T1-MRI; segmentation of the spinal cord was found to be poor. Comparison with CT-based automatic segmentation suggests that the process is equally as, or more accurate, using MRI. These results support further translation of MRI-based segmentation methodology into clinicalpractice. PMID:27455480

  11. Investigation on the performance of dedicated radiotherapy positioning devices for MR scanning for prostate planning.

    PubMed

    Sun, Jidi; Dowling, Jason A; Pichler, Peter; Parker, Joel; Martin, Jarad; Stanwell, Peter; Arm, Jameen; Menk, Fred; Greer, Peter B

    2015-01-01

    The purpose of this study was to investigate performance of the couch and coil mounts designed for MR-simulation prostate scanning using data from ten volunteers. Volunteers were scanned using the standard MR scanning protocol with the MR coil directly strapped on the external body and the volunteer lying on the original scanner table. They also were scanned using a MR-simulation table top and pelvic coil mounts. MR images from both setups were compared in terms of body contour variation and image quality effects within particular organs of interest. Six-field conformal plans were generated on the two images with assigned bulk density for dose calculation. With the MR-simulation devices, the anterior skin deformation was reduced by up to 1.7 cm. The hard tabletop minimizes the posterior body deformation which can be up to 2.3 cm on the standard table, depending on the weight of volunteer. The image signal-to-noise ratio reduced by 14% and 25% on large field of view (FOV) and small FOV images, respectively, after using the coil mount; the prostate volume contoured on two images showed difference of 1.05 ± 0.66 cm3. The external body deformation caused a mean dose reduction of 0.6 ± 0.3 Gy, while the coverage reduced by 22% ± 13% and 27% ± 6% in V98 and V100, respectively. A dedicated MR simulation setup for prostate radiotherapy is essential to ensure the agreement between planning anatomy and treatment anatomy. The image signal was reduced after applying the coil mount, but no significant effect was found on prostate contouring. PMID:26103166

  12. MRI-based measurements of respiratory motion variability and assessment of imaging strategies for radiotherapy planning

    NASA Astrophysics Data System (ADS)

    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

  13. Quantitative dosimetric assessment for effect of gold nanoparticles as contrast media on radiotherapy planning

    NASA Astrophysics Data System (ADS)

    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

  14. Recommendations for dose calculations of lung cancer treatment plans treated with stereotactic ablative body radiotherapy (SABR)

    NASA Astrophysics Data System (ADS)

    Devpura, S.; Siddiqui, M. S.; Chen, D.; Liu, D.; Li, H.; Kumar, S.; Gordon, J.; Ajlouni, M.; Movsas, B.; Chetty, I. J.

    2014-03-01

    The purpose of this study was to systematically evaluate dose distributions computed with 5 different dose algorithms for patients with lung cancers treated using stereotactic ablative body radiotherapy (SABR). Treatment plans for 133 lung cancer patients, initially computed with a 1D-pencil beam (equivalent-path-length, EPL-1D) algorithm, were recalculated with 4 other algorithms commissioned for treatment planning, including 3-D pencil-beam (EPL-3D), anisotropic analytical algorithm (AAA), collapsed cone convolution superposition (CCC), and Monte Carlo (MC). The plan prescription dose was 48 Gy in 4 fractions normalized to the 95% isodose line. Tumors were classified according to location: peripheral tumors surrounded by lung (lung-island, N=39), peripheral tumors attached to the rib-cage or chest wall (lung-wall, N=44), and centrally-located tumors (lung-central, N=50). Relative to the EPL-1D algorithm, PTV D95 and mean dose values computed with the other 4 algorithms were lowest for "lung-island" tumors with smallest field sizes (3-5 cm). On the other hand, the smallest differences were noted for lung-central tumors treated with largest field widths (7-10 cm). Amongst all locations, dose distribution differences were most strongly correlated with tumor size for lung-island tumors. For most cases, convolution/superposition and MC algorithms were in good agreement. Mean lung dose (MLD) values computed with the EPL-1D algorithm were highly correlated with that of the other algorithms (correlation coefficient =0.99). The MLD values were found to be ~10% lower for small lung-island tumors with the model-based (conv/superposition and MC) vs. the correction-based (pencil-beam) algorithms with the model-based algorithms predicting greater low dose spread within the lungs. This study suggests that pencil beam algorithms should be avoided for lung SABR planning. For the most challenging cases, small tumors surrounded entirely by lung tissue (lung-island type), a Monte

  15. Energy Dependence of Measured CT Numbers on Substituted Materials Used for CT Number Calibration of Radiotherapy Treatment Planning Systems

    PubMed Central

    Mahmoudi, Reza; Jabbari, Nasrollah; aghdasi, Mehdi; Khalkhali, Hamid Reza

    2016-01-01

    Introduction 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. Materials and Methods 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. Results 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%. Discussion 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. PMID:27391672

  16. MO-H-19A-01: FEATURED PRESENTATION - Treatment Planning Tool for Radiotherapy with Very High-Energy Electron Beams

    SciTech Connect

    Bazalova, M; Qu, B; Palma, B; Loo, B; Maxim, P; Hynning, E; Hardemark, B

    2014-06-15

    Purpose: To develop a tool for treatment planning optimization for fast radiotherapy delivered with very high-energy electron beams (VHEE) and to compare VHEE plans to state-of-the-art plans for challenging pelvis and H'N cases. Methods: Treatment planning for radiotherapy delivered with VHEE scanning pencil beams was performed by integrating EGSnrc Monte Carlo (MC) dose calculations with spot scanning optimization run in a research version of RayStation. A Matlab GUI for MC beamlet generation was developed, in which treatment parameters such as the pencil beam size and spacing, energy and number of beams can be selected. Treatment planning study for H'N and pelvis cases was performed and the effect of treatment parameters on the delivered dose distributions was evaluated and compared to the clinical treatment plans. The pelvis case with a 691cm3 PTV was treated with 2-arc 15MV VMAT and the H'N case with four PTVs with total volume of 531cm3 was treated with 4-arc 6MV VMAT. Results: Most studied VHEE plans outperformed VMAT plans. The best pelvis 80MeV VHEE plan with 25 beams resulted in 12% body dose sparing and 8% sparing to the bowel and right femur compared to the VMAT plan. The 100MeV plan was superior to the 150MeV plan. Mixing 100 and 150MeV improved dose sparing to the bladder by 7% compared to either plan. Plans with 16 and 36 beams did not significantly affect the dose distributions compared to 25 beam plans. The best H'N 100MeV VHEE plan decreased mean doses to the brainstem, chiasm, and both globes by 10-42% compared to the VMAT plan. Conclusion: The pelvis and H'N cases suggested that sixteen 100MeV beams might be sufficient specifications of a novel VHEE treatment machine. However, optimum machine parameters will be determined with the presented VHEE treatment-planning tool for a large number of clinical cases. BW Loo and P Maxim received research support from RaySearch Laboratories. E Hynning and B Hardemark are employees of RaySearch Laboratories.

  17. Development of a novel treatment planning test for credentialing rotational intensity-modulated radiotherapy techniques in the UK

    PubMed Central

    Ciurlionis, L; Clark, C; Venables, K

    2013-01-01

    Objective: The increasing use of tomotherapy and volumetric-modulated arc therapy in UK centres will result in more centres choosing to use this technology in a clinical trial setting. The Radiotherapy Trials Quality Assurance (RTTQA) group has developed a new procedure to integrate into the UK intensity-modulated radiotherapy (IMRT) credentialing programme to cover rotational IMRT delivery techniques. Methods: A planning test [three-dimensional treatment planning system (3DTPS)] was designed specifically for rotational IMRT techniques. The feasibility of using this test in the credentialing programme for rotational IMRT was validated by 10 experienced UK centres. The study included five centres using Varian RapidArc™ (RA) (Varian Medical Systems, Milpitas, CA), two using Elekta VMAT™ (VMAT) (Elekta Inc., Norcross, GA) and three using helical tomotherapy (HT) plans. Centres were asked to carry out their own in-house quality assurance (QA) for the plans submitted for this study. A survey was sent out to centres aiming to gather information on their experience in undertaking the exercise and their QA results. Results: All centres fulfilled the primary goal by achieving the dose constraints of the primary planning target volume and organ at risk. Seven centres (three RA, one VMAT and three HT plans) were able to fulfil the secondary goal. Among those seven centres, three centres (two RA and one VMAT plans) achieved the tertiary goal. The results of the survey indicated that the 3DTPS test is a clinically relevant and practical planning test to be used. Conclusion: A planning test for rotational therapy techniques was developed for the RTTQA IMRT credentialing programme. Advances in knowledge: This study validated the feasibility of a 3DTPS test to be used as part of a credentialing programme for rotational IMRT techniques in the UK. PMID:23385993

  18. Parotid Gland Dose in Intensity-Modulated Radiotherapy for Head and Neck Cancer: Is What You Plan What You Get?

    SciTech Connect

    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

    2007-11-15

    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. A hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Lei, Yu; Wu, Qiuwen

    2010-04-01

    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

  20. Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation.

    PubMed

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

    2014-02-01

    Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

  1. Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

  2. Volumetric-modulated arc radiotherapy for pancreatic malignancies: Dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy

    SciTech Connect

    Nabavizadeh, Nima Simeonova, Anna O.; Waller, Joseph G.; Romer, Jeanna L.; Monaco, Debra L.; Elliott, David A.; Tanyi, James A.; Fuss, Martin; Thomas, Charles R.; Holland, John M.

    2014-10-01

    Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction external beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.

  3. Monte Carlo Simulations for Dosimetry in Prostate Radiotherapy with Different Intravesical Volumes and Planning Target Volume Margins

    PubMed Central

    Lv, Wei; Yu, Dong; He, Hengda; Liu, Qian

    2016-01-01

    In prostate radiotherapy, the influence of bladder volume variation on the dose absorbed by the target volume and organs at risk is significant and difficult to predict. In addition, the resolution of a typical medical image is insufficient for visualizing the bladder wall, which makes it more difficult to precisely evaluate the dose to the bladder wall. This simulation study aimed to quantitatively investigate the relationship between the dose received by organs at risk and the intravesical volume in prostate radiotherapy. The high-resolution Visible Chinese Human phantom and the finite element method were used to construct 10 pelvic models with specific intravesical volumes ranging from 100 ml to 700 ml to represent bladders of patients with different bladder filling capacities during radiotherapy. This series of models was utilized in six-field coplanar 3D conformal radiotherapy simulations with different planning target volume (PTV) margins. Each organ’s absorbed dose was calculated using the Monte Carlo method. The obtained bladder wall displacements during bladder filling were consistent with reported clinical measurements. The radiotherapy simulation revealed a linear relationship between the dose to non-targeted organs and the intravesical volume and indicated that a 10-mm PTV margin for a large bladder and a 5-mm PTV margin for a small bladder reduce the effective dose to the bladder wall to similar degrees. However, larger bladders were associated with evident protection of the intestines. Detailed dosimetry results can be used by radiation oncologists to create more accurate, individual water preload protocols according to the patient’s anatomy and bladder capacity. PMID:27441944

  4. 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

    SciTech Connect

    Pommier, Pascal; Dussart, Sophie; Girinsky, Theodore; Chabaud, Sylvie; Lagrange, Jean Leon; Nguyen, Tan Dat; Beckendorff, Veronique; D'Hombres, Anne; Artignan, Xavier; Bondiau, Pierre Yves; Carrie, Christian; Giammarile, Francesco

    2011-03-01

    Purpose: 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. Patients and Methods: 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. Results: 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. Conclusion: 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.

  5. Fully Automated Simultaneous Integrated Boosted-Intensity Modulated Radiation Therapy Treatment Planning Is Feasible for Head-and-Neck Cancer: A Prospective Clinical Study

    SciTech Connect

    Wu Binbin; McNutt, Todd; Zahurak, Marianna; Simari, Patricio; Pang, Dalong; Taylor, Russell; Sanguineti, Giuseppe

    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.

  6. Radiation planning comparison for superficial tissue avoidance in radiotherapy for soft tissue sarcoma of the lower extremity

    SciTech Connect

    Griffin, Anthony M.; Euler, Colleen I.; Sharpe, Michael B.; Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S.; Chung, Peter W.M.; Catton, Charles N.; O'Sullivan, Brian . E-mail: brian.osullivan@rmp.uhn.on.ca

    2007-03-01

    Purpose: Three types of preoperative radiotherapy (RT) plans for extremity soft tissue sarcoma were compared to determine the amount of dose reduction possible to the planned surgical skin flaps required for tumor resection and wound closure, without compromising target coverage. Methods and Materials: Twenty-four untreated patients with large, deep, lower extremity STS treated with preoperative RT and limb salvage surgery had their original conventional treatment plans re-created. The same clinical target volume was used for all three plans. The future surgical skin flaps were created virtually through contouring by the treating surgeon and regarded as an organ at risk. The original, conformal, and intensity-modulated RT (IMRT) plans were created to deliver 50 Gy in 25 fractions to the clinical target volume. Clinical target volume and organ-at-risk dose-volume histograms were calculated and the plans compared for conformality, target coverage, and dose sparing. Results: The mean dose to the planned skin flaps was 42.62 Gy (range, 30.24-48.65 Gy) for the original plans compared with 40.12 Gy (range, 24.24-47.26 Gy) for the conformal plans and 26.71 Gy (range, 22.31-31.91 Gy) for the IMRT plans (p = 0.0008). An average of 86.4% (range, 53.2-97.4%) of the planned skin flaps received {>=}30 Gy in the original plans compared with 83.4% (range, 36.2-96.2%) in the conformal plans and only 34.0% (range, 22.5-53.3%) in the IMRT plans (p = 0.0001). IMRT improved target conformality compared with the original and conformal plans (1.27, 2.34, and 1.76, respectively, p = 0.0001). Conclusion: In a retrospective review, preoperative IMRT substantially lowered the dose to the future surgical skin flaps, sparing a greater percentage of this structure's volume without compromising target (tumor) coverage.

  7. Biochemical Imaging of Gliomas Using MR Spectroscopic Imaging for Radiotherapy Treatment Planning

    NASA Astrophysics Data System (ADS)

    Heikal, Amr Ahmed

    This thesis discusses the main obstacles facing wide clinical implementation of magnetic resonance spectroscopic imaging (MRSI) as a tumor delineation tool for radiotherapy treatment planning, particularly for gliomas. These main obstacles are identified as 1. observer bias and poor interpretational reproducibility of the results of MRSI scans, and 2. the long scan times required to conduct MRSI scans. An examination of an existing user-independent MRSI tumor delineation technique known as the choline-to-NAA index (CNI) is conducted to assess its utility in providing a tool for reproducible interpretation of MRSI results. While working with spatial resolutions typically twice those on which the CNI model was originally designed, a region of statistical uncertainty was discovered between the tumor and normal tissue populations and as such a modification to the CNI model was introduced to clearly identify that region. To address the issue of long scan times, a series of studies were conducted to adapt a scan acceleration technique, compressed sensing (CS), to work with MRSI and to quantify the effects of such a novel technique on the modulation transfer function (MTF), an important quantitative imaging metric. The studies included the development of the first phantom based method of measuring the MTF for MRSI data, a study of the correlation between the k-space sampling patterns used for compressed sensing and the resulting MTFs, and the introduction of a technique circumventing some of side-effects of compressed sensing by exploiting the conjugate symmetry property of k-space. The work in this thesis provides two essential steps towards wide clinical implementation of MRSI-based tumor delineation. The proposed modifications to the CNI method coupled with the application of CS to MRSI address the two main obstacles outlined. However, there continues to be room for improvement and questions that need to be answered by future research.

  8. Optimising delineation accuracy of tumours in PET for radiotherapy planning using blind deconvolution

    PubMed Central

    Guvenis, A.; Koc, A.

    2015-01-01

    Positron emission tomography (PET) imaging has been proven to be useful in radiotherapy planning for the determination of the metabolically active regions of tumours. Delineation of tumours, however, is a difficult task in part due to high noise levels and the partial volume effects originating mainly from the low camera resolution. The goal of this work is to study the effect of blind deconvolution on tumour volume estimation accuracy for different computer-aided contouring methods. The blind deconvolution estimates the point spread function (PSF) of the imaging system in an iterative manner in a way that the likelihood of the given image being the convolution output is maximised. In this way, the PSF of the imaging system does not need to be known. Data were obtained from a NEMA NU-2 IQ-based phantom with a GE DSTE-16 PET/CT scanner. The artificial tumour diameters were 13, 17, 22, 28 and 37 mm with a target/background ratio of 4:1. The tumours were delineated before and after blind deconvolution. Student's two-tailed paired t-test showed a significant decrease in volume estimation error (p < 0.001) when blind deconvolution was used in conjunction with computer-aided delineation methods. A manual delineation confirmation demonstrated an improvement from 26 to 16 % for the artificial tumour of size 37 mm while an improvement from 57 to 15 % was noted for the small tumour of 13 mm. Therefore, it can be concluded that blind deconvolution of reconstructed PET images may be used to increase tumour delineation accuracy. PMID:25836686

  9. Is Planned Neck Dissection Necessary for Head and Neck Cancer After Intensity-Modulated Radiotherapy?

    SciTech Connect

    Yao Min |. E-mail: min-yao@uiowa.edu; Hoffman, Henry T.; Funk, Gerry F. |; Chang, Kristi; Smith, Russell B. |; Tan Huaming; Clamon, Gerald H.; Dornfeld, Ken |; Buatti, John M. |

    2007-07-01

    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 [{sup 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 [{sup 18}F] fluorodeoxyglucose positron emission tomography is a useful tool in selecting patients appropriate for neck dissection.

  10. Cine Computed Tomography Without Respiratory Surrogate in Planning Stereotactic Radiotherapy for Non-Small-Cell Lung Cancer

    SciTech Connect

    Riegel, Adam C. B.A.; Chang, Joe Y.; Vedam, Sastry S.; Johnson, Valen; Chi, Pai-Chun Melinda; Pan, Tinsu

    2009-02-01

    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.