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Sample records for meningioma imrt treatment

  1. [68Ga]-DOTATOC-PET/CT for meningioma IMRT treatment planning

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    Bamberg Michael

    2009-11-01

    Full Text Available Abstract Purpose The observation that human meningioma cells strongly express somatostatin receptor (SSTR 2 was the rationale to analyze retrospectively in how far DOTATOC PET/CT is helpful to improve target volume delineation for intensity modulated radiotherapy (IMRT. Patients and Methods In 26 consecutive patients with preferentially skull base meningioma, diagnostic magnetic resonance imaging (MRI and planning-computed tomography (CT was complemented with data from [68Ga]-DOTA-D Phe1-Tyr3-Octreotide (DOTATOC-PET/CT. Image fusion of PET/CT, diagnostic computed tomography, MRI and radiotherapy planning CT as well as target volume delineation was performed with OTP-Masterplan®. Initial gross tumor volume (GTV definition was based on MRI data only and was secondarily complemented with DOTATOC-PET information. Irradiation was performed as EUD based IMRT, using the Hyperion Software package. Results The integration of the DOTATOC data led to additional information concerning tumor extension in 17 of 26 patients (65%. There were major changes of the clinical target volume (CTV which modify the PTV in 14 patients, minor changes were realized in 3 patients. Overall the GTV-MRI/CT was larger than the GTV-PET in 10 patients (38%, smaller in 13 patients (50% and almost the same in 3 patients (12%. Most of the adaptations were performed in close vicinity to bony skull base structures or after complex surgery. Median GTV based on MRI was 18.1 cc, based on PET 25.3 cc and subsequently the CTV was 37.4 cc. Radiation planning and treatment of the DOTATOC-adapted volumes was feasible. Conclusion DOTATOC-PET/CT information may strongly complement patho-anatomical data from MRI and CT in cases with complex meningioma and is thus helpful for improved target volume delineation especially for skull base manifestations and recurrent disease after surgery.

  2. Current treatment options for meningioma.

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    Apra, Caroline; Peyre, Matthieu; Kalamarides, Michel

    2018-03-01

    With an annual incidence of 5/100,000, meningioma is the most frequent primary tumor of the central nervous system. Risk factors are radiotherapy and hormone intake. Most meningiomas are grade I benign tumors, but up to 15% are atypical and 2% anaplastic according to the WHO 2016 histological criteria. Areas covered: This review details the current standard therapy based on international guidelines and recent literature, and describes new approaches developed to treat refractory cases. First-line treatments are observation and surgery, but adjuvant radiotherapy/radiosurgery is discussed for atypical and indicated for anaplastic meningiomas. The most problematic cases include skull base meningiomas that enclose vasculo-nervous structures and surgery- and radiation-refractory tumors that present with significant morbidity and mortality. The treatment of recurrent tumors is based on radiotherapy and repeated surgery. Systematic therapies are not effective in general but several clinical trials are ongoing. Expert commentary: Molecular characterization of the tumors, based on genetic mutations such as NF2, SMO, TERT, TRAF7, and on the methylation profile are developing, completing the histological classification and giving new insights into prognosis and treatment options.

  3. Clinical diagnosis and treatment of olfactory meningioma

    International Nuclear Information System (INIS)

    Li Xiangdong; Wang Zhong; Zhang Shiming; Zhu Fengqing; Zhou Dai; Hui Guozhen

    2005-01-01

    Objective: To analyze the clinical diagnosis and treatment of olfactory meningioma. Methods: In this group 17 olfactory meningiomas were operated, and the clinical presentations and the surgery results were obtained. Results: The symptoms of psychiatrical disorder, visual disturbances and eclipse at presentation was higher. In 16 cases the grade of resection was Simpson II, 1 case Simpson III, most of the cases had a good recovery. Conclusion: Attention should be paid to the early symptom at presentation such as psychiatrical disorder to obtain an early diagnosis. Microsurgery is useful in the treatment of olfactory meningioma. (authors)

  4. Meningioma

    International Nuclear Information System (INIS)

    Windt, H.L. de.

    1981-01-01

    131 Cases of meningioma, of which 113 were intracranial and 18 intraspinal, are reviewed retrospectively on the basis of the clinical findings. In the first category the history and neurological findings are combined. In category II the following investigations are discussed. In evaluation of plain X-rays of sphenoid meningiomas, it appears that 66.7% are abnormal. The EEG investigation generally correlates with the hemisphere in which the tumor is located. The isotope investigation (test) appears to be of great value in screening for meningioma, and is almost 100% abnormal. The CT scan is a rather welcome contribution in the diagnostic procedure for evaluation of meningioma. Category III discusses findings upon operation. (Auth.)

  5. Meningioma

    Science.gov (United States)

    ... meningioma is a tumor that arises from the meninges — the membranes that surround your brain and spinal ... know that something alters some cells in your meninges to make them multiply out of control, leading ...

  6. Benign meningiomas: primary treatment selection affects survival

    International Nuclear Information System (INIS)

    Condra, Kellie S.; Buatti, John M.; Mendenhall, William M.; Friedman, William A.; Marcus, Robert B.; Rhoton, Albert L.

    1997-01-01

    Purpose: To examine the effect of primary treatment selection on outcomes for benign intracranial meningiomas at the University of Florida. Methods and Materials: For 262 patients, the impact of age, Karnofsky performance status, pathologic features, tumor size, tumor location, and treatment modality on local control and cause-specific survival was analyzed (minimum potential follow-up, 2 years; median follow-up, 8.2 years). Extent of surgery was classified by Simpson grade. Treatment groups: surgery alone (n = 229), surgery and postoperative radiotherapy (RT) (n = 21), RT alone (n = 7), radiosurgery alone (n = 5). Survival analysis: Kaplan-Meier method with univariate and multivariate analysis. Results: At 15 years, local control was 76% after total excision (TE) and 87% after subtotal excision plus RT (SE+RT), both significantly better (p = 0.0001) than after SE alone (30%). Cause-specific survival at 15 years was reduced after treatment with SE alone (51%), compared with TE (88%) or SE+RT (86%) (p = 0.0003). Recurrence after primary treatment portended decreased survival, independent of initial treatment group or salvage treatment selection (p = 0.001). Atypical pathologic features predicted reduced 15-year local control (54 vs. 71%) and cause-specific survival rates (57 vs. 86%). Multivariate analysis for cause-specific survival revealed treatment group (SE vs. others; p = 0.0001), pathologic features (atypical vs. typical; p = 0.0056), and Karnofsky performance status (≥80 vs. <80; p = 0.0153) as significant variables. Conclusion: Benign meningiomas are well managed by TE or SE+RT. SE alone is inadequate therapy and adversely affects cause-specific survival. Atypical pathologic features predict a poorer outcome, suggesting possible benefit from more aggressive treatment. Because local recurrence portends lower survival rates, primary treatment choice is important

  7. Role of radiotherapy in the treatment of meningiomas

    International Nuclear Information System (INIS)

    Noel, G.; Renard, A.; Mazeron, J.J.; Valery, C.; Mokhtari, K.

    2001-01-01

    Role of radiotherapy in the treatment of meningiomas. Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively. (authors)

  8. Proton Stereotactic Radiosurgery for the Treatment of Benign Meningiomas

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    Halasz, Lia M., E-mail: lhalasz@partners.org [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Bussiere, Marc R.; Dennis, Elizabeth R.; Niemierko, Andrzej [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Chapman, Paul H. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Loeffler, Jay S.; Shih, Helen A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States)

    2011-12-01

    Purpose: Given the excellent prognosis for patients with benign meningiomas, treatment strategies to minimize late effects are important. One strategy is proton radiation therapy (RT), which allows less integral dose to normal tissue and greater homogeneity than photon RT. Here, we report the first series of proton stereotactic radiosurgery (SRS) used for the treatment of meningiomas. Methods and Materials: We identified 50 patients with 51 histologically proven or image- defined, presumed-benign meningiomas treated at our institution between 1996 and 2007. Tumors of <4 cm in diameter and located {>=}2 mm from the optic apparatus were eligible for treatment. Indications included primary treatment (n = 32), residual tumor following surgery (n = 8), and recurrent tumor following surgery (n = 10). The median dose delivered was 13 Gray radiobiologic equivalent (Gy[RBE]) (range, 10.0-15.5 Gy[RBE]) prescribed to the 90% isodose line. Results: Median follow-up was 32 months (range, 6-133 months). Magnetic resonance imaging at the most recent follow-up or time of progression revealed 33 meningiomas with stable sizes, 13 meningiomas with decreased size, and 5 meningiomas with increased size. The 3-year actuarial tumor control rate was 94% (95% confidence interval, 77%-98%). Symptoms were improved in 47% (16/ 34) of patients, unchanged in 44% (15/34) of patients, and worse in 9% (3/34) of patients. The rate of potential permanent adverse effects after SRS was 5.9% (3/51 patients). Conclusions: Proton SRS is an effective therapy for small benign meningiomas, with a potentially lower rate of long-term treatment-related morbidity. Longer follow-up is needed to assess durability of tumor control and late effects.

  9. Meningioma as second malignant neoplasm after oncological treatment during childhood

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    Mueller, H.L.; Gebhardt, U. [Klinikum Oldenburg (Germany). Dept. of Pediatric Hematology and Oncology; Warmuth-Metz, M. [University Hospital Wuerzburg (Germany). Dept. of Neuroradiology; Pietsch, T. [Bonn Univ. (Germany). Dept. of Neuropathology; Soerensen, N. [Evangelisches Krankenhaus, Oldenburg (Germany). Dept. of Neurosurgery; Kortmann, R.D. [University Hospital Leipzig (Germany). Dept. of Radiooncology

    2012-05-15

    A total of 38 patients (18 female/20 male) with childhood meningioma were recruited from the German registry HIT-Endo (1989-2009). In 5 cases meningioma occurred as second malignant neoplasm (SMN). Histologies were confirmed by reference assessment in all cases (SMN: 2 WHO I, 1 WHO II, 2 WHO III). The SMNs were diagnosed at a median age of 12.4 years with a median latency of 10.2 years after primary malignancy (PMN; 4 brain tumors, 1 lymphoblastic leukemia; median age at diagnosis 2.7 years). Meningioma occurred as SMN in the irradiated field of PMN (range 12-54 Gy). The outcome after treatment of SMN meningioma (surgery/irradiation) was favorable in terms of psychosocial status and functional capacity in 4 of 5 patients (1 death). We conclude that survivors of childhood cancer who were exposed to radiation therapy at young age harbor the risk of developing meningioma as a SMN at a particularly short latency period in case of high dose exposure. (orig.)

  10. Stereotactic radiosurgery for the treatment of meningiomas; Radiocirurgia estereotaxica no tratamento de meningiomas

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    Penna, Antonio Belmiro Rodrigues Campbell [Hospital dos Servidores do Estado, Rio de Janeiro, RJ (Brazil). Servico de Radioterapia; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Vieira, Sergio Lannes [Hospital Sao Vicente de Paula, Rio de Janeiro, RJ (Brazil). Servico de Radioterapia; Rossini Junior, Olamir [Clinica Radioterapia Botafogo Ltda., Rio de Janeiro, RJ (Brazil)

    2000-04-01

    We report the results of the treatment of four patients with inoperable meningiomas who underwent stereotactic radiosurgery using a linear accelerator of 6 MeV. Radiological examinations carried out from 12 to 22 months later revealed tumor growth arrest in all patients, giving a response rate of 100%. No early or late neurological complications dur to the radiosurgical treatment was observed. During the follow-up period no death caused by radiation was reported. Although the number of cases and the follow-up period were insufficient to show statistical significance, the results were satisfactory and thus require further investigations. (author)

  11. The treatment for asymptomatic meningiomas in the era of radiosurgery

    International Nuclear Information System (INIS)

    Iwai, Yoshiyasu; Yamanaka, Kazuhiro; Morikawa, Toshie; Ishiguro, Tomoya; Honda, Yuji; Matsusaka, Yasuhiro; Komiyama, Masaki; Yasui, Toshihiro

    2003-01-01

    We evaluated the treatment results in asymptomatic meningiomas in the era of radiosurgery. We encountered 56 patients with asymptomatic meningiomas from January, 1994 to December, 2001. There were 16 male patients and 40 female patients. The most common location was the cerebral convexity. We performed gamma knife radiosurgery for three patients after diagnosis of cavernous sinus meningiomas. The other patients were followed-up after diagnosis for a mean follow-up period of 30.8 months (5 months to 8 years). Tumor growth was verified in 25 patients (43%) and two patients (3.7%) suffered neurological deficits. Among the tumor growth patients, operative resection was performed in six patients (11%) and gamma knife radiosurgery was performed in four patients (7.5%). The other patients were placed under observation. We decided the treatment strategy paying attention to the tumor location, tumor growth speed, tumor size and operative difficulty. The tumor growth rate was 0.1 cm/year among the patients with tumor growth. It was 0.72 cm/year (0.02 to 1.54 cm/year) in the operative group, 0.3 cm/year (0.04 to 0.76 cm/year) in the gamma knife radiosurgery group and 0.08 cm/year (0.01 to 0.76 cm/year) in the observed group. One patient suffered procedure-related deterioration of paresis after operation. The treatment of asymptomatic meningiomas must be decided depending on their natural history and locations. We recommend early radiosurgery for cavernous sinus meningiomas. (author)

  12. Combination of peptide receptor radionuclide therapy with fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma

    International Nuclear Information System (INIS)

    Kreissl, Michael C; Flentje, Michael; Sweeney, Reinhart A; Hänscheid, Heribert; Löhr, Mario; Verburg, Frederik A; Schiller, Markus; Lassmann, Michael; Reiners, Christoph; Samnick, Samuel S; Buck, Andreas K

    2012-01-01

    External beam radiotherapy (EBRT) is the treatment of choice for irresectable meningioma. Due to the strong expression of somatostatin receptors, peptide receptor radionuclide therapy (PRRT) has been used in advanced cases. We assessed the feasibility and tolerability of a combination of both treatment modalities in advanced symptomatic meningioma. 10 patients with irresectable meningioma were treated with PRRT ( 177 Lu-DOTA0,Tyr3 octreotate or - DOTA0,Tyr3 octreotide) followed by external beam radiotherapy (EBRT). EBRT performed after PRRT was continued over 5–6 weeks in IMRT technique (median dose: 53.0 Gy). All patients were assessed morphologically and by positron emission tomography (PET) before therapy and were restaged after 3–6 months. Side effects were evaluated according to CTCAE 4.0. Median tumor dose achieved by PRRT was 7.2 Gy. During PRRT and EBRT, no side effects > CTCAE grade 2 were noted. All patients reported stabilization or improvement of tumor-associated symptoms, no morphologic tumor progression was observed in MR-imaging (median follow-up: 13.4 months). The median pre-therapeutic SUV max in the meningiomas was 14.2 (range: 4.3–68.7). All patients with a second PET after combined PRRT + EBRT showed an increase in SUV max (median: 37%; range: 15%–46%) to a median value of 23.7 (range: 8.0–119.0; 7 patients) while PET-estimated volume generally decreased to 81 ± 21% of the initial volume. The combination of PRRT and EBRT is feasible and well tolerated. This approach represents an attractive strategy for the treatment of recurring or progressive symptomatic meningioma, which should be further evaluated

  13. Phantoms for IMRT dose distribution measurement and treatment verification

    International Nuclear Information System (INIS)

    Low, Daniel A.; Gerber, Russell L.; Mutic, Sasa; Purdy, James A.

    1998-01-01

    Background: The verification of intensity-modulated radiation therapy (IMRT) patient treatment dose distributions is currently based on custom-built or modified dose measurement phantoms. The only commercially available IMRT treatment planning and delivery system (Peacock, NOMOS Corp.) is supplied with a film phantom that allows accurate spatial localization of the dose distribution using radiographic film. However, measurements using other dosimeters are necessary for the thorough verification of IMRT. Methods: We have developed a phantom to enable dose measurements using a cylindrical ionization chamber and the localization of prescription isodose curves using a matrix of thermoluminescent dosimetry (TLD) chips. The external phantom cross-section is identical to that of the commercial phantom, to allow direct comparisons of measurements. A supplementary phantom has been fabricated to verify the IMRT dose distributions for pelvis treatments. Results: To date, this phantom has been used for the verification of IMRT dose distributions for head and neck and prostate cancer treatments. Designs are also presented for a phantom insert to be used with polymerizing gels (e.g., BANG-2) to obtain volumetric dose distribution measurements. Conclusion: The phantoms have proven useful in the quantitative evaluation of IMRT treatments

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  15. Neuroradiological diagnosis and microsurgical treatment of suprasellar meningiomas

    International Nuclear Information System (INIS)

    Pfisterer, W.

    1991-01-01

    Meningiomas are extracerebrale tumours of the central nervous system. The percental share of this brain neoplasms amounts to 10 - 15 %. Suprasellar meningiomas have a narrow relation to the nervus opticus, hypothalamus, A. carotis interna, A. cerebri anterior and A. carotis media. This explains the clinical-neurological-symptoms. With aid of angiography, CT, magnetic resonance imaging and microneurosurgery the mortality can be decreased from 50 % to 5 %. (Botek)

  16. Skull base meningioma. Surgical and adjuvant treatment with clinical and PET evaluation

    International Nuclear Information System (INIS)

    Gudjonsson, O.

    2001-01-01

    The treatment strategy for skull base meningiomas remains a controversial issue. Because of the proximity of these tumours to critical neurovascular structures, the risk for vascular damage and new cranial neuropathies postoperatively is significant. To avoid unacceptable neurological deficits the surgical treatment strategy includes different surgical approaches and a subtotal removal of these tumours in some cases. However, because the rate of recurrence and progression is significant in these patients, a demand for adjuvant treatment and better prognostic methods is called for so that treatment and follow-up can be tailored to each patient. Accordingly, we have chosen to evaluate general outcome and facial nerve function after translabyrinthine and transcochlear approaches for cerebellopontine angle (CPA) meningiomas. Furthermore, we have evaluated two adjuvant treatments, namely, irradiation by high-energy proton beams and medical treatment with interferon-alpha as well as evaluation of the treatment effect with 11 C-L-methionine PET. In addition, we have evaluated a new PET tracer ( 76 Br-BrdU) for 'in vivo' determination of the growth potential of intracranial tumours. Conclusion: The translabyrinthine and transcochlear approaches are apparently safe surgical procedures in the treatment of CPA meningiomas. Proton beam therapy is technically feasible as suggested by the fact that only minimal side effects were observed. Moreover, none of the meningiomas treated have shown progression during a 36-month follow-up. Our results indicate that IFN-alpha can be an effective oncostatic treatment for certain patients with meningiomas. The 11 C-L-methionine PET method might be used as a complement to CT or MRI in the evaluation of the effect of proton beam and IFN-alpha treatment in meningiomas. The present attempt failed to demonstrate that the PET tracer 76 Br-BrdU could be used for the non-invasive characterisation of growth potential in brain, tumours

  17. Skull base meningioma. Surgical and adjuvant treatment with clinical and PET evaluation

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    Gudjonsson, O

    2001-05-01

    The treatment strategy for skull base meningiomas remains a controversial issue. Because of the proximity of these tumours to critical neurovascular structures, the risk for vascular damage and new cranial neuropathies postoperatively is significant. To avoid unacceptable neurological deficits the surgical treatment strategy includes different surgical approaches and a subtotal removal of these tumours in some cases. However, because the rate of recurrence and progression is significant in these patients, a demand for adjuvant treatment and better prognostic methods is called for so that treatment and follow-up can be tailored to each patient. Accordingly, we have chosen to evaluate general outcome and facial nerve function after translabyrinthine and transcochlear approaches for cerebellopontine angle (CPA) meningiomas. Furthermore, we have evaluated two adjuvant treatments, namely, irradiation by high-energy proton beams and medical treatment with interferon-alpha as well as evaluation of the treatment effect with {sup 11}C-L-methionine PET. In addition, we have evaluated a new PET tracer ({sup 76}Br-BrdU) for 'in vivo' determination of the growth potential of intracranial tumours. Conclusion: The translabyrinthine and transcochlear approaches are apparently safe surgical procedures in the treatment of CPA meningiomas. Proton beam therapy is technically feasible as suggested by the fact that only minimal side effects were observed. Moreover, none of the meningiomas treated have shown progression during a 36-month follow-up. Our results indicate that IFN-alpha can be an effective oncostatic treatment for certain patients with meningiomas. The {sup 11}C-L-methionine PET method might be used as a complement to CT or MRI in the evaluation of the effect of proton beam and IFN-alpha treatment in meningiomas. The present attempt failed to demonstrate that the PET tracer {sup 76}Br-BrdU could be used for the non-invasive characterisation of growth potential in

  18. Endocavitary in vivo Dosimetry for IMRT Treatments of Gynecologic Tumors

    International Nuclear Information System (INIS)

    Cilla, Savino; Macchia, Gabriella; Digesù, Cinzia; Deodato, Francesco; Sabatino, Domenico; Morganti, Alessio G.; Piermattei, Angelo

    2011-01-01

    The accuracy and reproducibility of endometrial carcinoma treatment with intensity-modulated radiotherapy (IMRT) was assessed by means of in vivo dosimetry. Six patients who had previously undergone radical hysterectomy for endometrial carcinoma were treated with IMRT using a vaginal applicator with radio-opaque fiducial markers. An ion-chamber inserted into the applicator supplied an endocavitary in vivo dosimetry for quality assurance purposes. The ratio R = D/D TPS between the in vivo measured dose D and the predicted dose by the treatment planning system D TPS was determined for every fraction of the treatment. Results showed that 90% and 100% of the ratios resulted equal to 1 within 5% and 10%, respectively. The mean value of the ratios distribution for the 6 patients was R = 0.995 and the SD = 0.034. The ratio R* between the measured and predicted total doses for each patient was near to 1, within 2%. The dosimetric results suggest that the use of a vaginal applicator in an image-guided approach could make the interfractions target position stable and reproducible, allowing a safe use of the IMRT technique in the treatment of postoperative vaginal vault. In vivo dosimetry may supply useful information about the discrimination of random vs. systematic errors. The workload is minimum and this in vivo dosimetry can be applied also in the clinical routine.

  19. Stereotactic IMRT using a MMLC

    International Nuclear Information System (INIS)

    Hoban, P.; Short, R.; Biggs, D.; Rose, A.; Smee, R.; Schneider, M.

    2001-01-01

    Full text: The leaf width of the multileaf collimator (MLC) used for intensity modulated radiotherapy (IMRT ) largely determines the resolution of the intensity maps that define the entire profile of each beam. In turn it is this resolution, and consequently the achievable degree of beam modulation, that determines the ability to conform the 3D dose distribution to complex target volumes. As such, the leaf width is of more importance than in fixed-field MLC treatments where only the beam edges are affected.A Radionics micro-multileaf collimator (MMLC) with 4 mm leaf width, attached to a Siemens Primus linear accelerator, is in use for stereotactic IMRT at PbWH. Treatment planning is performed with the XPlan system including an integrated IMRT module. Cases treated have so far been with conventional fractionation, including both malignant and benign cranial lesions. Meningiomas in particular often require a complex dose distribution because of their en-plaque nature and/or proximity to the brainstem. Stereotactic localisation and fixation is with the Gill-Thomas-Cosman head-ring or Head and Neck localiser. Cases are typically planned both for fixed-field treatment and IMRT, with IMRT being used if significant benefit is seen. IMRT treatment with the Siemens MLC is also an option. A quality assurance system has been set up, including a flowchart/checklist and phantom dosimetry using TLDs. As expected, treatment plans show IMRT with the MMLC to consistently be the best option dosimetrically. In particular, for a given target coverage there is always better sparing of nearby organs at risk (OARs) with MMLC rather than MLC-based IMRT. Adjustments such as the inclusion of a margin around the target volume or an increase in the penalty for target underdosage improve coverage for MLC plans but generally at the expense of increased OAR involvement. MMLC IMRT treatments commonly require 30-50 fields and can be delivered in approximately 10-15 minutes using an autosequence

  20. IMRT treatment of anal cancer with a scrotal shield

    International Nuclear Information System (INIS)

    Hood, Rodney C.; Wu, Q. Jackie; McMahon, Ryan; Czito, Brian; Willett, Christopher

    2012-01-01

    The risk of sterility in males undergoing radiotherapy in the pelvic region indicates the use of a shielding device, which offers protection to the testes for patients wishing to maintain fertility. The use of such devices in the realm of intensity-modulated radiotherapy (IMRT) in the pelvic region can pose many obstacles during simulation, treatment planning, and delivery of radiotherapy. This work focuses on the development and execution of an IMRT plan for the treatment of anal cancer using a scrotal shielding device on a clinical patient. An IMRT plan was developed using Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA), using a wide array of gantry angles as well as fixed jaw and fluence editing techniques. When possible, the entire target volume was encompassed by the treatment field. When the beam was incident on the scrotal shield, the jaw was fixed to avoid the device and the collimator rotation optimized to irradiate as much of the target as possible. This technique maximizes genital sparing and allows minimal irradiation of the gonads. When this fixed-jaw technique was found to compromise adequate coverage of the target, manual fluence editing techniques were used to avoid the shielding device. Special procedures for simulation, imaging, and treatment verification were also developed. In vivo dosimetry was used to verify and ensure acceptable dose to the gonads. The combination of these techniques resulted in a highly conformal plan that spares organs and risk and avoids the genitals as well as entrance of primary radiation onto the shielding device.

  1. IMRT treatment of anal cancer with a scrotal shield.

    Science.gov (United States)

    Hood, Rodney C; Wu, Q Jackie; McMahon, Ryan; Czito, Brian; Willett, Christopher

    2012-01-01

    The risk of sterility in males undergoing radiotherapy in the pelvic region indicates the use of a shielding device, which offers protection to the testes for patients wishing to maintain fertility. The use of such devices in the realm of intensity-modulated radiotherapy (IMRT) in the pelvic region can pose many obstacles during simulation, treatment planning, and delivery of radiotherapy. This work focuses on the development and execution of an IMRT plan for the treatment of anal cancer using a scrotal shielding device on a clinical patient. An IMRT plan was developed using Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA), using a wide array of gantry angles as well as fixed jaw and fluence editing techniques. When possible, the entire target volume was encompassed by the treatment field. When the beam was incident on the scrotal shield, the jaw was fixed to avoid the device and the collimator rotation optimized to irradiate as much of the target as possible. This technique maximizes genital sparing and allows minimal irradiation of the gonads. When this fixed-jaw technique was found to compromise adequate coverage of the target, manual fluence editing techniques were used to avoid the shielding device. Special procedures for simulation, imaging, and treatment verification were also developed. In vivo dosimetry was used to verify and ensure acceptable dose to the gonads. The combination of these techniques resulted in a highly conformal plan that spares organs and risk and avoids the genitals as well as entrance of primary radiation onto the shielding device. Copyright © 2012 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  2. An Approach for Practical Multiobjective IMRT Treatment Planning

    International Nuclear Information System (INIS)

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

    2007-01-01

    Purpose: To introduce and demonstrate a practical multiobjective treatment planning procedure for intensity-modulated radiation therapy (IMRT) planning. Methods and Materials: The creation of a database of Pareto optimal treatment plans proceeds in two steps. The first step solves an optimization problem that finds a single treatment plan which is close to a set of clinical aspirations. This plan provides an example of what is feasible, and is then used to determine mutually satisfiable hard constraints for the subsequent generation of the plan database. All optimizations are done using linear programming. Results: The two-step procedure is applied to a brain, a prostate, and a lung case. The plan databases created allow for the selection of a final treatment plan based on the observed tradeoffs between the various organs involved. Conclusions: The proposed method reduces the human iteration time common in IMRT treatment planning. Additionally, the database of plans, when properly viewed, allows the decision maker to make an informed final plan selection

  3. MENINGIOMAS: A CLINICOPATHOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Shri Lakshmi S

    2015-10-01

    Full Text Available Introduction: Meningiomas are tumors that arise from the meningothelial cells. Most of these tumors are intracranial; some are intraspinal and few extra cranial. There are many histological variants classified into three grades depending on clinical behavior. Classification is important for determining the modality of treatment. Objectives: To study the incidence, location, sex and age predilection, histological variants and grading of meningiomas based on WHO 2007 classification and recurrence if present. Materials and methods: All128 cases of meningiomas. Based on Histological features, typing and grading of meningiomas was done as per the WHO 2007 classification of Meningiomas. Age, Sex incidence, Location of meningiomas were studied. Results: Meningiomas comprised 25.25% of all CNS tumors during the study period. Of 507 CNS tumors, 128 were meningiomas. Most of them were intracranial, predominantly involving the convexities of brain, females and the 41 – 50 age group. Of these, 116 were benign grade I tumors, 9 were grade II and 3 were grade III. The most common histological variant was fibroblastic and meningothelial. Intraspinal meningiomas were 16 (12.5% cases with the psammomatous variant being more common. Grade II and Grade III tumors located in parafalcine or parasagittal area commonly recurred. Conclusion: Meningiomas are slow growing tumors arising from the meningothelial cells accounting for 25.25% of all CNS neoplasms showing a variety of histological patterns, more common in women, predominantly Grade I tumors. Recurrence of tumors depends on histological grade and extent of surgery.

  4. Gamma knife surgery-induced ependymoma after the treatment of meningioma - a case report.

    Science.gov (United States)

    Wang, Ke; Pan, Li; Che, Xiaoming; Lou, Meiqing

    2012-01-01

    Gamma knife surgery is widely used for a number of neurological disorders. However, little is known about its long-term complications such as carcinogenic risks. Here, we present a case of a radiosurgery-induced ependymoma by gamma knife surgery for the treatment of a spinal meningioma in a 7-year-old patient. In light of reviewing the previous reports, we advocate high caution in making young patients receive this treatment.

  5. Radiotherapy through intensity modulation (IMRT). A new modality in the treatment of head and neck cancer

    International Nuclear Information System (INIS)

    Besa de C, Pelayo; Venencia M, Daniel

    2006-01-01

    Objective: To describe the treatment and evaluate the advantages of IMRT in the treatment of head and neck cancer. Material and methods: Four years ago, at the Cancer Center of the Pontificia Universidad Catolica, the IMRT technique for the treatment of head and neck tumors was implemented. The IMRT technique is based on modifying the intensity of the radiation beam through a multisheet collimator in order to produce a more exact distribution in the radiation doses. The results are evaluated with dose/ volume histograms. The distributions of doses and toxicity for tridimensional con formed therapy (CRT-3D) and IMRT are compared. Results: The distribution of the dose in the dose/volume histograms showed a better coverage of the white volume (PTV), with IMRT. The doses received by the organs under risk: salivary glands, eyes, ears and brain diminish with IMRT. The spinal marrow is protected with IMRT without dividing the treatment area, preventing points with lower dosage that could reduce control of the tumor. Conclusions: IMRT achieves a better conformation of the dose obtaining a better coverage of the tumor and higher protection of the organs under risk

  6. Dosimetric comparison of standard three-dimensional conformal radiotherapy followed by intensity-modulated radiotherapy boost schedule (sequential IMRT plan) with simultaneous integrated boost-IMRT (SIB IMRT) treatment plan in patients with localized carcinoma prostate.

    Science.gov (United States)

    Bansal, A; Kapoor, R; Singh, S K; Kumar, N; Oinam, A S; Sharma, S C

    2012-07-01

    DOSIMETERIC AND RADIOBIOLOGICAL COMPARISON OF TWO RADIATION SCHEDULES IN LOCALIZED CARCINOMA PROSTATE: Standard Three-Dimensional Conformal Radiotherapy (3DCRT) followed by Intensity Modulated Radiotherapy (IMRT) boost (sequential-IMRT) with Simultaneous Integrated Boost IMRT (SIB-IMRT). Thirty patients were enrolled. In all, the target consisted of PTV P + SV (Prostate and seminal vesicles) and PTV LN (lymph nodes) where PTV refers to planning target volume and the critical structures included: bladder, rectum and small bowel. All patients were treated with sequential-IMRT plan, but for dosimetric comparison, SIB-IMRT plan was also created. The prescription dose to PTV P + SV was 74 Gy in both strategies but with different dose per fraction, however, the dose to PTV LN was 50 Gy delivered in 25 fractions over 5 weeks for sequential-IMRT and 54 Gy delivered in 27 fractions over 5.5 weeks for SIB-IMRT. The treatment plans were compared in terms of dose-volume histograms. Also, Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) obtained with the two plans were compared. The volume of rectum receiving 70 Gy or more (V > 70 Gy) was reduced to 18.23% with SIB-IMRT from 22.81% with sequential-IMRT. SIB-IMRT reduced the mean doses to both bladder and rectum by 13% and 17%, respectively, as compared to sequential-IMRT. NTCP of 0.86 ± 0.75% and 0.01 ± 0.02% for the bladder, 5.87 ± 2.58% and 4.31 ± 2.61% for the rectum and 8.83 ± 7.08% and 8.25 ± 7.98% for the bowel was seen with sequential-IMRT and SIB-IMRT plans respectively. For equal PTV coverage, SIB-IMRT markedly reduced doses to critical structures, therefore should be considered as the strategy for dose escalation. SIB-IMRT achieves lesser NTCP than sequential-IMRT.

  7. Head-and-neck IMRT treatments assessed with a Monte Carlo dose calculation engine

    International Nuclear Information System (INIS)

    Seco, J; Adams, E; Bidmead, M; Partridge, M; Verhaegen, F

    2005-01-01

    IMRT is frequently used in the head-and-neck region, which contains materials of widely differing densities (soft tissue, bone, air-cavities). Conventional methods of dose computation for these complex, inhomogeneous IMRT cases involve significant approximations. In the present work, a methodology for the development, commissioning and implementation of a Monte Carlo (MC) dose calculation engine for intensity modulated radiotherapy (MC-IMRT) is proposed which can be used by radiotherapy centres interested in developing MC-IMRT capabilities for research or clinical evaluations. The method proposes three levels for developing, commissioning and maintaining a MC-IMRT dose calculation engine: (a) development of a MC model of the linear accelerator, (b) validation of MC model for IMRT and (c) periodic quality assurance (QA) of the MC-IMRT system. The first step, level (a), in developing an MC-IMRT system is to build a model of the linac that correctly predicts standard open field measurements for percentage depth-dose and off-axis ratios. Validation of MC-IMRT, level (b), can be performed in a rando phantom and in a homogeneous water equivalent phantom. Ultimately, periodic quality assurance of the MC-IMRT system is needed to verify the MC-IMRT dose calculation system, level (c). Once the MC-IMRT dose calculation system is commissioned it can be applied to more complex clinical IMRT treatments. The MC-IMRT system implemented at the Royal Marsden Hospital was used for IMRT calculations for a patient undergoing treatment for primary disease with nodal involvement in the head-and-neck region (primary treated to 65 Gy and nodes to 54 Gy), while sparing the spinal cord, brain stem and parotid glands. Preliminary MC results predict a decrease of approximately 1-2 Gy in the median dose of both the primary tumour and nodal volumes (compared with both pencil beam and collapsed cone). This is possibly due to the large air-cavity (the larynx of the patient) situated in the centre

  8. Role of radiotherapy in the treatment of meningiomas; Role de la radiotherapie dans le traitement des meningiomes cerebraux

    Energy Technology Data Exchange (ETDEWEB)

    Noel, G. [Centre de protontherapie, 91 - Orsay (France); Renard, A.; Mazeron, J.J. [Groupe Hospitalier la Pitie-Salpetriere, Service de Radiotherapie, AP-HP, 75 - Paris (France); Valery, C. [Groupe Hospitalier la Pitie-Salpetriere, Service de Neurochirurgie, AP-HP, 75 - Paris (France); Mokhtari, K. [Groupe Hospitalier la Pitie-Salpetriere, Lab. de Neuropathologie Raymond-Escourolle, AP-HP, 75 - Paris (France)

    2001-06-01

    Role of radiotherapy in the treatment of meningiomas. Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively. (authors)

  9. Evaluation of a commercial biologically based IMRT treatment planning system

    International Nuclear Information System (INIS)

    Semenenko, Vladimir A.; Reitz, Bodo; Day, Ellen; Qi, X. Sharon; Miften, Moyed; Li, X. Allen

    2008-01-01

    A new inverse treatment planning system (TPS) for external beam radiation therapy with high energy photons is commercially available that utilizes both dose-volume-based cost functions and a selection of cost functions which are based on biological models. The purpose of this work is to evaluate quality of intensity-modulated radiation therapy (IMRT) plans resulting from the use of biological cost functions in comparison to plans designed using a traditional TPS employing dose-volume-based optimization. Treatment planning was performed independently at two institutions. For six cancer patients, including head and neck (one case from each institution), prostate, brain, liver, and rectal cases, segmental multileaf collimator IMRT plans were designed using biological cost functions and compared with clinically used dose-based plans for the same patients. Dose-volume histograms and dosimetric indices, such as minimum, maximum, and mean dose, were extracted and compared between the two types of treatment plans. Comparisons of the generalized equivalent uniform dose (EUD), a previously proposed plan quality index (fEUD), target conformity and heterogeneity indices, and the number of segments and monitor units were also performed. The most prominent feature of the biologically based plans was better sparing of organs at risk (OARs). When all plans from both institutions were combined, the biologically based plans resulted in smaller EUD values for 26 out of 33 OARs by an average of 5.6 Gy (range 0.24 to 15 Gy). Owing to more efficient beam segmentation and leaf sequencing tools implemented in the biologically based TPS compared to the dose-based TPS, an estimated treatment delivery time was shorter in most (five out of six) cases with some plans showing up to 50% reduction. The biologically based plans were generally characterized by a smaller conformity index, but greater heterogeneity index compared to the dose-based plans. Overall, compared to plans based on dose

  10. Fast film dosimetry calibration method for IMRT treatment plan verification

    International Nuclear Information System (INIS)

    Schwob, N.; Wygoda, A.

    2004-01-01

    Intensity-Modulated Radiation Therapy (IMRT) treatments are delivered dynamically and as so, require routinely performed verification measurements [1]. Radiographic film dosimetry is a well-adapted method for integral measurements of dynamic treatments fields, with some drawbacks related to the known problems of dose calibration of films. Classically, several films are exposed to increasing doses, and a Net Optical Density (N.O.D) vs. dose sensitometric curve (S.C.) is generated. In order to speed up the process, some authors have developed a method based on the irradiation of a single film with a non-uniform pattern of O.D., delivered with a dynamic MLC. However, this curve still needs to be calibrated to dose by the means of measurements in a water phantom. It is recommended to make a new calibration for every series of measurements, in order to avoid the processing quality dependence of the film response. These frequent measurements are very time consuming. We developed a simple method for quick dose calibration of films, including a check of the accuracy of the calibration curve obtained

  11. A Comprehensive Comparison of IMRT and VMAT Plan Quality for Prostate Cancer Treatment

    International Nuclear Information System (INIS)

    Quan, Enzhuo M.; Li Xiaoqiang; Li Yupeng; Wang Xiaochun; Kudchadker, Rajat J.; Johnson, Jennifer L.; Kuban, Deborah A.; Lee, Andrew K.; Zhang Xiaodong

    2012-01-01

    Purpose: We performed a comprehensive comparative study of the plan quality between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for the treatment of prostate cancer. Methods and Materials: Eleven patients with prostate cancer treated at our institution were randomly selected for this study. For each patient, a VMAT plan and a series of IMRT plans using an increasing number of beams (8, 12, 16, 20, and 24 beams) were examined. All plans were generated using our in-house–developed automatic inverse planning (AIP) algorithm. An existing eight-beam clinical IMRT plan, which was used to treat the patient, was used as the reference plan. For each patient, all AIP-generated plans were optimized to achieve the same level of planning target volume (PTV) coverage as the reference plan. Plan quality was evaluated by measuring mean dose to and dose–volume statistics of the organs at risk, especially the rectum, from each type of plan. Results: For the same PTV coverage, the AIP-generated VMAT plans had significantly better plan quality in terms of rectum sparing than the eight-beam clinical and AIP-generated IMRT plans (p < 0.0001). However, the differences between the IMRT and VMAT plans in all the dosimetric indices decreased as the number of beams used in IMRT increased. IMRT plan quality was similar or superior to that of VMAT when the number of beams in IMRT was increased to a certain number, which ranged from 12 to 24 for the set of patients studied. The superior VMAT plan quality resulted in approximately 30% more monitor units than the eight-beam IMRT plans, but the delivery time was still less than 3 min. Conclusions: Considering the superior plan quality as well as the delivery efficiency of VMAT compared with that of IMRT, VMAT may be the preferred modality for treating prostate cancer.

  12. State-of-the-art treatment alternatives for base of skull meningiomas: complementing and controversial indications for neurosurgery, stereotactic and robotic based radiosurgery or modern fractionated radiation techniques

    International Nuclear Information System (INIS)

    Combs, Stephanie E; Ganswindt, Ute; Foote, Robert L; Kondziolka, Douglas; Tonn, Jörg-Christian

    2012-01-01

    For skull base meningiomas, several treatment paradigms are available: Observation with serial imaging, surgical resection, stereotactic radiosurgery, radiation therapy or some combination of both. The choice depends on several factors. In this review we evaluate different treatment options, the outcome of modern irradiation techniques as well as the clinical results available, and establish recommendations for the treatment of patients with skull-base meningiomas

  13. Does IMRT increase the peripheral radiation dose? A comparison of treatment plans 2000 and 2010

    International Nuclear Information System (INIS)

    Salz, Henning; Eichner, Regina; Wiezorek, Tilo

    2012-01-01

    It has been reported in several papers and textbooks that IMRT treatments increase the peripheral dose in comparison with non-IMRT fields. But in clinical practice not only open fields have been used in the pre-IMRT era, but also fields with physical wedges or composed fields. The aim of this work is to test the hypothesis of increased peripheral dose when IMRT is used compared to standard conformal radiotherapy. Furthermore, the importance of the measured dose differences in clinical practice is discussed and compared with other new technologies for the cases where an increase of the peripheral dose was observed. For cancers of the head and neck, the cervix, the rectum and for the brain irradiation due to acute leukaemia, one to four plans have been calculated with IMRT or conformal standard technique (non-IMRT). In an anthropomorphic phantom the dose at a distance of 30 cm in cranio-caudal direction from the target edge was measured with TLDs using a linear accelerator Oncor registered (Siemens) for both techniques. IMRT was performed using step-and-shoot technique (7 to 11 beams), non-IMRT plans with different techniques. The results depended on the site of irradiation. For head and neck cancers IMRT resulted in an increase of 0.05 - 0.09% of the prescribed total dose (Dptv) or 40 - 70 mGy (Dptv = 65 Gy), compared to non-IMRT technique without wedges or a decrease of 0.16% (approx. 100 mGy) of the prescribed total dose compared to non-IMRT techniques with wedges. For the cervical cancer IMRT resulted in an increased dose in the periphery (+ 0.07% - 0.15% of Dptv or 30 - 70 mGy at Dptv = 45 Gy), for the rectal cancer in a dose reduction (0.21 - 0.26% of Dptv or 100 - 130 mGy at Dptv = 50 Gy) and for the brain irradiation in an increase dose (+ 0.05% of Dptv = 18 Gy or 9 mSv). In summary IMRT does not uniformly cause increased radiation dose in the periphery in the model used. It can be stated that these dose values are smaller than reported in earlier papers

  14. Dose evaluation of TPS according to treatment sites in IMRT

    International Nuclear Information System (INIS)

    Kim, Jin Man; Kim, Jong Sik; Hong, Chae Seon; Park, Ju Young; Park, Su Yeon; Ju, Sang Gyu

    2013-01-01

    This study executed therapy plans on prostate cancer (homogeneous density area) and lung cancer (non-homogeneous density area) using radiation treatment planning systems such as Pinnacle 3 (version 9.2, Philips Medical Systems, USA) and Eclipse (version 10.0, Varian Medical Systems, USA) in order to quantify the difference between dose calculation according to density in IMRT. The subjects were prostate cancer patients (n=5) and lung cancer patients (n=5) who had therapies in our hospital. Identical constraints and optimization process according to the Protocol were administered on the subjects. For the therapy plan of prostate cancer patients, 10 MV and 7Beam were used and 2.5 Gy was prescribed in 28 fx to make 70 Gy in total. For lung cancer patients, 6 MV and 6Beam were used and 2 Gy was prescribed in 33 fx to make 66 Gy in total. Through two therapy planning systems, maximum dose, average dose, and minimum dose of OAR (Organ at Risk) of CTV, PTV and around tumor were investigated. In prostate cancer, both therapy planning systems showed within 2% change of dose of CTV and PTV and normal organs (Bladder, Both femur and Rectum out) near the tumor satisfied the dose constraints. In lung cancer, CTV and PTV showed less than 2% changes in dose and normal organs (Esophagus, Spinal cord and Both lungs) satisfied dose restrictions. However, the minimum dose of Eclipse therapy plan was 1.9% higher in CTV and 3.5% higher in PTV, and in case of both lungs there was 3.0% difference at V5 Gy. Each TPS according to the density satisfied dose limits of our hospital proving the clinical accuracy. It is considered more accurate and precise therapy plan can be made if studies on treatment planning for diverse parts and the application of such TPS are made

  15. SU-E-T-521: Feasibility Study of a Rotational Step-And-Shoot IMRT Treatment Planning Approach

    International Nuclear Information System (INIS)

    Zhu, X; Chang, S; Cullip, T; Yuan, L; Zhang, X; Lian, J; Tang, X; Tracton, G; Dooley, J

    2014-01-01

    Purpose: Rotational step-and-shot IMRT (r-IMRT) could improve delivery efficiency with good dose conformity, especially if it can leverage the burst mode of the accelerator where radiation is turned on/off momentarily while the gantry rotates continuously. The challenge for the r-IMRT planning is to minimize the number of beams to achieve a fast and smooth rotational delivery. Methods: Treatment plans for r-IMRT were created using an in-house treatment planning system. To generate the plan using a very few beams, gantry angle was optimized by weighting the beam monitoring unit (MU), and beam shape optimization was a combination of column search with k-means clustering. A prostate case and a head and neck case were planned using r-IMRT. The dosimetry is compared to s-IMRT planned with Varian Eclipse treatment planning system. Results: With the same PTV dose coverage D95=100%, the r-IMRT plans shows comparable sparing as the s-IMRT plans in the prostate for the rectum D10cc and the bladder Dmean, and in the head and neck for the spinal cord Dmax, the brain stem Dmax, the left/right parotid Dmean, the larynx Dmean, and the mandible Dmean. Both plans meet the established institutional clinical dosimetric criteria. The r-IMRT plan uses 19 beam/405 MU for the prostate, and 68 beam/880 MU for the head and neck, while the s-IMRT uses 7 beam/724 MU and 9 beam/1812 MU, respectively. Compared to the corresponding s-IMRT, r-IMRT has a reduction of MUs of 44% for the prostate case and 41% for the head and neck case. Conclusions: We have demonstrated the feasibility of a rotational step and shoot IMRT treatment planning approach that significantly shortens the conventional IMRT treatment beam-on time without degrading the dose comformity

  16. SU-E-T-521: Feasibility Study of a Rotational Step-And-Shoot IMRT Treatment Planning Approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X [Univ. of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Chang, S [UNC School of Medicine, Chapel Hill, NC (United States); Cullip, T [UNC Hospitals, Chapel Hill, NC (United States); Yuan, L; Zhang, X [Duke University, Durham, NC (United States); Lian, J; Tang, X [UniversityNorth Carolina, Chapel Hill, NC (United States); Tracton, G; Dooley, J [University of North Carolina, Chapel Hill, NC (United States)

    2014-06-01

    Purpose: Rotational step-and-shot IMRT (r-IMRT) could improve delivery efficiency with good dose conformity, especially if it can leverage the burst mode of the accelerator where radiation is turned on/off momentarily while the gantry rotates continuously. The challenge for the r-IMRT planning is to minimize the number of beams to achieve a fast and smooth rotational delivery. Methods: Treatment plans for r-IMRT were created using an in-house treatment planning system. To generate the plan using a very few beams, gantry angle was optimized by weighting the beam monitoring unit (MU), and beam shape optimization was a combination of column search with k-means clustering. A prostate case and a head and neck case were planned using r-IMRT. The dosimetry is compared to s-IMRT planned with Varian Eclipse treatment planning system. Results: With the same PTV dose coverage D95=100%, the r-IMRT plans shows comparable sparing as the s-IMRT plans in the prostate for the rectum D10cc and the bladder Dmean, and in the head and neck for the spinal cord Dmax, the brain stem Dmax, the left/right parotid Dmean, the larynx Dmean, and the mandible Dmean. Both plans meet the established institutional clinical dosimetric criteria. The r-IMRT plan uses 19 beam/405 MU for the prostate, and 68 beam/880 MU for the head and neck, while the s-IMRT uses 7 beam/724 MU and 9 beam/1812 MU, respectively. Compared to the corresponding s-IMRT, r-IMRT has a reduction of MUs of 44% for the prostate case and 41% for the head and neck case. Conclusions: We have demonstrated the feasibility of a rotational step and shoot IMRT treatment planning approach that significantly shortens the conventional IMRT treatment beam-on time without degrading the dose comformity.

  17. Prospective evaluation of early treatment outcome in patients with meningiomas treated with particle therapy based on target volume definition with MRI and {sup 68}Ga-DOTATOC-PET

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephanie E.; Welzel, Thomas; Habermehl, Daniel; Rieken, Stefan; Dittmar, Jan-Oliver; Kessel, Kerstin; Debus, Juergen [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)], e-mail: Stephanie.Combs@med.uni-heidelberg.de; Jaekel, Oliver [Heidelberg Ion Therapy Center (HIT), Heidelberg (Germany); Haberkorn, Uwe [Univ. Hospital of Heidelberg, Dept. of Nuclear Medicine, Heidelberg (Germany)

    2013-04-15

    Purpose: To evaluate early treatment results and toxicity in patients with meningiomas treated with particle therapy. Material and methods: Seventy patients with meningiomas were treated with protons (n = 38) or carbon ion radiotherapy (n = 26). Median age was 49 years. Median age at treatment was 55 years, 24 were male (34%), and 46 were female (66%). Histology was benign meningioma in 26 patients (37%), atypical in 23 patients (33%) and anaplastic in four patients (6%). In 17 patients (24%) with skull base meningiomas diagnosis was based on the typical appearance of a meningioma. For benign meningiomas, total doses of 52.2-57.6 GyE were applied with protons. For high-grade lesions, the boost volume was 18 GyE carbon ions, with a median dose of 50 GyE applied as highly conformal radiation therapy. Nineteen patients were treated as re-irradiation. Treatment planning with MRI and 68-Ga-DOTATOC-PET was evaluated. Results: Very low rates of side effects developed, including headaches, nausea and dizziness. No severe treatment-related toxicity was observed. Local control for benign meningiomas was 100%. Five of 27 patients (19%) developed tumor recurrence during follow-up. Of these, four patients had been treated as re-irradiation for recurrent high-risk meningiomas. Actuarial local control after re-irradiation of high-risk meningiomas was therefore 67% at six and 12 months. In patients treated with primary radiotherapy, only one of 13 patients (8%) developed tumor recurrence 17 months after radiation therapy (photon and carbon ion boost). Conclusion: Continuous prospective follow-up and development of novel study concepts are required to fully exploit the long-term clinical data after particle therapy for meningiomas. To date, it may be concluded that when proton therapy is available, meningioma patients can be offered a treatment at least comparable to high-end photon therapy.

  18. Impact of MLC properties and IMRT technique in meningioma and head-and-neck treatments

    DEFF Research Database (Denmark)

    Kantz, Steffi; Söhn, Matthias; Troeller, Almut

    2015-01-01

    for each patient. Only larynx, parotids and eyes differ up to 1.5 Gy (Dmean or Dmax) or 7% (volume-constraint) due to (1) increased scatter, (2) not avoiding structures when using the full range of gantry rotation and (3) improved leaf sequencing with advanced segment shape optimization for VMAT plans. EUD...

  19. Treatment accuracy of hypofractionated spine and other highly conformal IMRT treatments

    International Nuclear Information System (INIS)

    Sutherland, B.; Hanlon, P.; Charles, P.

    2011-01-01

    Full text: Spinal cord metastases pose difficult challenges for radiation treatment due to tight dose constraints and a concave PTY. This project aimed to thoroughly test the treatment accuracy of the Eclipse Treatment Planning System (TPS) for highly modulated IMRT treatments, in particular of the thoracic spine, using an Elekta Synergy Linear Accelerator. The increased understanding obtained through different quality assurance techniques allowed recommendations to be made for treatment site commissioning with improved accuracy at the Princess Alexandra Hospital (PAH). Three thoracic spine IMRT plans at the PAH were used for data collection. Complex phantom models were built using CT data, and fields simulated using Monte Carlo modelling. The simulated dose distributions were compared with the TPS using gamma analysis and DYH comparison. High resolution QA was done for all fields using the MatriXX ion chamber array, MapCHECK2 diode array shifted, and the EPlD to determine a procedure for commissioning new treatment sites. Basic spine simulations found the TPS overestimated absorbed dose to bone, however within spinal cord there was good agreement. High resolution QA found the average gamma pass rate of the fields to be 99.1 % for MatriXX, 96.5% for MapCHECK2 shifted and 97.7% for EPlD. Preliminary results indicate agreement between the TPS and delivered dose distributions higher than previously believed for the investigated IMRT plans. The poor resolution of the MatriXX, and normalisation issues with MapCHECK2 leads to probable recommendation of EPlD for future IMRT commissioning due to the high resolution and minimal setup required.

  20. In Vivo Diode Dosimetry for Imrt Treatments Generated by Pinnacle Treatment Planning System

    International Nuclear Information System (INIS)

    Alaei, Parham; Higgins, Patrick D.; Gerbi, Bruce J.

    2009-01-01

    Dose verification using diodes has been proposed and used for intensity modulated radiation therapy (IMRT) treatments. We have previously evaluated diode response for IMRT deliveries planned with the Eclipse/Helios treatment planning system. The Pinnacle treatment planning system generates plans that are delivered in a different fashion than Eclipse. Whereas the Eclipse-generated segments are delivered in organized progression from one side of each field to the other, Pinnacle-generated segments are delivered in a much more randomized fashion to different areas within the field. This makes diode measurements at a point more challenging because the diode may be exposed fully or partially to multiple small segments during one single field's treatment as opposed to being exposed to very few segments scanning across the diode during an Eclipse-generated delivery. We have evaluated in vivo dosimetry for Pinnacle-generated IMRT plans and characterized the response of the diode to various size segments on phantom. We present results of patient measurements on approximately 300 fields, which show that 76% of measurements agree to within 10% of the treatment-plan generated calculated doses. Of the other 24%, about 11% are within 15% of the calculated dose. Comparison of these with phantom measurements indicates that many of the discrepancies are due to diode positioning on patients and increased diode response at short source-to-surface distances (SSDs), with the remainder attributable to other factors such as segment size and partial irradiation of the diode

  1. Efficacy of external fractionated radiation therapy in the treatment of meningiomas: a 20-year experience

    International Nuclear Information System (INIS)

    Pourel, Nicolas; Auque, Jean; Bracard, Serge; Hoffstetter, Sylvette; Luporsi, Elisabeth; Vignaud, Jean-Michek; Bey, Pierre

    2001-01-01

    Background: This is a retrospective analysis of a series of meningiomas treated by radiotherapy. Materials and methods: From 1978 to 1997, 45 patients with intracranial meningiomas were referred for external fractionated radiotherapy at Centre Alexis Vautrin. All patients were given 50-70 Gy to the tumor bed (median: 56 Gy), 1.8-2 Gy per fraction. Results: Evaluation was performed in June 1999 using the Kaplan-Meyer actuarial method with a median follow-up of 30 months (range: 1-166), relapse-free survivals (RFSs) were 75% at 5 years and 67% at 8 years; overall survival (OS) was 74% at 5 and 8 years. For the 26 benign histologically documented lesions, RFSs were 95% at 5 years and 81% at 8 years; OS was 85% at 5 and 8 years. One major radiation-induced complication occurred in this series (decline of cognitive function). According to the indication of radiotherapy, we divided the series into four groups: postoperative irradiation after a first subtotal resection (11 patients), 5-year RFS was 90%; after first recurrence (±salvage surgery, 14 patients), 73%; after further recurrence (±salvage surgery, 11 patients), 67%; as exclusive treatment (nine patients), 80%. Atypical and malignant lesions (n=7) all relapsed before 24 months of follow-up, all patients but one died before 42 months. Age at the time of irradiation (≥60 vs. <60 years) and radiotherapy dose (≥60 vs. <60 Gy) did not influence local control or OS. Atypical and malignant lesions (WHO grades II and III) meningiomas had a worse outcome than benign lesions (WHO grade I, P<0.01). Conclusions: These results compare favorably with previously published data. External fractionated radiotherapy is well tolerated and effective. There is still a debate about the place of radiotherapy in the treatment of meningiomas: after subtotal resection, should radiotherapy be given postoperatively or at the time of progression? Should radiotherapy replace surgery when the risk of postoperative sequellae is high

  2. The surgical treatment strategy and results of parasellar meningiomas in the era of radiosurgery

    International Nuclear Information System (INIS)

    Iwai, Yoshiyasu; Yamanaka, Kazuhiro; Morikawa, Toshie; Ishiguro, Tomoya; Honda, Yuji; Matsuzaka, Yasuhiro; Komiyama, Masaki; Yasui, Toshihiro

    2003-01-01

    We evaluated the surgical treatment results of parasellar meningiomas in the era of radiosurgery. We treated 24 patients of parasellar meningiomas surgically. The median age was 60 yrs (ranging from 29 to 82 yrs). The most common tumor location was the sphenoid ridge in 12 patients and the tuberculum sellae in 7 patients. The pterional approach using fronto-temporal craniotomy was performed for all patients. The residual or recurrent tumors were treated by gamma knife radiosurgery (GKS). We are able to follow up these cases for a median of 3.8 yrs (ranging from 1 to 8 yrs) after the operations. The radicality of tumor resection was Simpson grade II in 13 patients (54%), grade III in 3 patients (13%) and grade IV in 7 patients (33%). Clinical improvement was achieved in 81% of the patients. Of the patients who had visual disturbance preoperatively, 8 patients (73%) showed improvement, but 3 patients suffered deterioration postoperatively. None of the patients died. One patient suffered transient memory disturbance and one patient suffered mild facial numbness postoperatively. Boost radiosurgery for the residual tumors was performed for six patients and tumor growth control was able to be achieved in all patients, with a median of 3.1 years follow-up period (ranging from 0.5 to 6 yrs). Five patients with tumor regrowth or recurrence were treated by GKS. We recommend fronto-temporal craniotomy with nonradical resection for parasellar meningiomas and radiosurgery for residual and recurrent tumors. This strategy will achieve good functional outcome with long-term tumor growth control. (author)

  3. Dosimetric comparison of treatment techniques IMRT and VMAT for breast cancer

    International Nuclear Information System (INIS)

    Urbina, G. L.; Garcia, B. G.

    2015-10-01

    In this study the dosimetric distribution was compared in the different treatment techniques such as Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) in female patients with breast cancer with stage II-B and III-A, 6 cases (both calculated on VMAT and IMRT) were studied, comparison parameter that are taken into account are: compliance rate, homogeneity index, monitor units, volume dose 50 Gy (D-50%) and 5 Gy (D-5%) volume dose. Comparisons are made in primary tumor volume to optimize treatment in patients with breast cancer, with IMRT using Step, Shoot and VMAT Monte Carlo algorithm, in addition to the organs at risk; the concern to make this work is due to technological advances in radiotherapy and the application of new treatment techniques, that increase the accuracy allowing treatment dose climbing delivering a higher dose to the patient. (Author)

  4. A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment.

    Science.gov (United States)

    Fuangrod, Todsaporn; Woodruff, Henry C; van Uytven, Eric; McCurdy, Boyd M C; Kuncic, Zdenka; O'Connor, Daryl J; Greer, Peter B

    2013-09-01

    To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient. The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance. The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s). A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.

  5. A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment

    Energy Technology Data Exchange (ETDEWEB)

    Fuangrod, Todsaporn [Faculty of Engineering and Built Environment, School of Electrical Engineering and Computer Science, the University of Newcastle, NSW 2308 (Australia); Woodruff, Henry C.; O’Connor, Daryl J. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308 (Australia); Uytven, Eric van; McCurdy, Boyd M. C. [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Radiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Kuncic, Zdenka [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Greer, Peter B. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)

    2013-09-15

    Purpose: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient.Methods: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance.Results: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s).Conclusions: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.

  6. A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment

    International Nuclear Information System (INIS)

    Fuangrod, Todsaporn; Woodruff, Henry C.; O’Connor, Daryl J.; Uytven, Eric van; McCurdy, Boyd M. C.; Kuncic, Zdenka; Greer, Peter B.

    2013-01-01

    Purpose: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient.Methods: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance.Results: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s).Conclusions: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy

  7. Dosimetric comparison of treatment techniques IMRT and VMAT for breast cancer; Comparacion dosimetrica de las tecnicas de tratamiento IMRT y VMAT para cancer en mama

    Energy Technology Data Exchange (ETDEWEB)

    Urbina, G. L. [Universidad Nacional de Ingenieria, Maestria en Fisica Medica, Av. Tupac Amaru s/n, Rimac, Lima 25 (Peru); Garcia, B. G., E-mail: gerlup@hotmail.com [Red AUNA, Clinica Delgado, Av. Angamos Cdra. 4 esquina Gral. Borgono, Miraflores, Lima (Peru)

    2015-10-15

    In this study the dosimetric distribution was compared in the different treatment techniques such as Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) in female patients with breast cancer with stage II-B and III-A, 6 cases (both calculated on VMAT and IMRT) were studied, comparison parameter that are taken into account are: compliance rate, homogeneity index, monitor units, volume dose 50 Gy (D-50%) and 5 Gy (D-5%) volume dose. Comparisons are made in primary tumor volume to optimize treatment in patients with breast cancer, with IMRT using Step, Shoot and VMAT Monte Carlo algorithm, in addition to the organs at risk; the concern to make this work is due to technological advances in radiotherapy and the application of new treatment techniques, that increase the accuracy allowing treatment dose climbing delivering a higher dose to the patient. (Author)

  8. Cervical Lymph Node Metastases fromMeningioma: Report of Two Cases andTreatment Outcome

    Directory of Open Access Journals (Sweden)

    Yahya Daneshbod

    2010-01-01

    Full Text Available Meningioma is usually a benign central nervous system (CNS tumor. Metastasisis rare; however if it does occur the most metastatic sites are the liver and lungs. Here,two cases of CNS meningioma with metastasis to cervical lymph nodes are reported.The first case, a 48 year-old man developed cervical lymph node metastasis nine yearsafter primary tumor diagnosis. The second case, a 23 year-old woman with parietallobe meningioma, developed lymph node metastasis in the neck nine months afterthe diagnosis of meningioma

  9. Implementation of dosimetric quality control on IMRT and VMAT treatments in radiotherapy using diodes

    International Nuclear Information System (INIS)

    Gonzales, A.; Garcia, B.; Ramirez, J.; Marquina, J.

    2014-08-01

    To implement quality control of IMRT and VMAT treatments Rapid Arc radiotherapy using diode array. Were tested 90 patients with IMRT and VMAT Rapid Arc, comparing the planned dose to the dose administered, used the Map-Check-2 and Arc-Check of Sun Nuclear, they using the gamma factor for calculating and using comparison parameters 3% / 3m m. The statistic shows that the quality controls of the 90 patients analyzed, presented a percentage of diodes that pass the test between 96,7% and 100,0% of the irradiated diodes. Implemented in Clinical ALIADA Oncologia Integral, the method for quality control of IMRT and VMAT treatments Rapid Arc radiotherapy using diode array. (Author)

  10. Clinicopathologic features of aggressive meningioma emphasizing the role of radiotherapy in treatment

    Energy Technology Data Exchange (ETDEWEB)

    Engenhart-Cabillic, R.; Henzel, M. [Philipps Univ., Marburg (Germany). Dept. of Radiotherapy and Radiooncology; Farhoud, A.; Sure, U.; Heinze, S.; Bertalanffy, H. [Philipps Univ., Marburg (Germany). Dept. of Neurosurgery; Mennel, H.D. [Philipps Univ., Marburg (Germany). Dept. of Neuropathology

    2006-11-15

    Background and Purpose: Although meningiomas are typically benign, they occasionally behave in an aggressive fashion and carry a less favorable prognosis. The aim of this study was to review the clinical, radiologic and histopathologic features of these aggressive variants as well as the outcome after multimodality therapy. Patients and Methods: 16 patients with atypical meningiomas (n=11) and anaplastic meningiomas (n=5) were treated in the Departments of Neurosurgery and Radiation Oncology at the University Hospital of Philipps University Marburg, Germany, between 1997 and 2003. Tumor grading was based on new WHO criteria. There were eleven men and five women with a mean age of 54 years. The median follow-up period was 34 months. Results: A total of 24 surgical procedures were performed for these 16 patients. Only seven patients underwent postoperative fractionated stereotactic radiotherapy. Patients with atypical meningioma received radiotherapy only for the recurrent disease. Six patients (37.5%) experienced tumor recurrence after a mean period of 27.2 months in spite of gross total resection. Radiographic findings suggestive of aggressiveness were observed mostly with WHO grade III meningiomas. By comparing the proliferation rate in four cases with atypical meningioma operated twice, the recurrent tumor had a higher proliferation rate than the first tumor in three cases. A special proliferation pattern was noticed in MIB-1 with anaplastic meningiomas. The mean overall survival period was 66.5 months. There was no mortality among patients with atypical meningioma, while four out of five patients with anaplastic meningioma died during follow-up. Conclusion: Considering the higher rate of recurrence in aggressive meningiomas even after radical surgical excision and the possibility that the recurrent tumor is more aggressive than the original one, surgery should be combined with postoperative fractionated radiotherapy to improve local tumor control. The peculiar

  11. Implementation of random set-up errors in Monte Carlo calculated dynamic IMRT treatment plans

    International Nuclear Information System (INIS)

    Stapleton, S; Zavgorodni, S; Popescu, I A; Beckham, W A

    2005-01-01

    The fluence-convolution method for incorporating random set-up errors (RSE) into the Monte Carlo treatment planning dose calculations was previously proposed by Beckham et al, and it was validated for open field radiotherapy treatments. This study confirms the applicability of the fluence-convolution method for dynamic intensity modulated radiotherapy (IMRT) dose calculations and evaluates the impact of set-up uncertainties on a clinical IMRT dose distribution. BEAMnrc and DOSXYZnrc codes were used for Monte Carlo calculations. A sliding window IMRT delivery was simulated using a dynamic multi-leaf collimator (DMLC) transport model developed by Keall et al. The dose distributions were benchmarked for dynamic IMRT fields using extended dose range (EDR) film, accumulating the dose from 16 subsequent fractions shifted randomly. Agreement of calculated and measured relative dose values was well within statistical uncertainty. A clinical seven field sliding window IMRT head and neck treatment was then simulated and the effects of random set-up errors (standard deviation of 2 mm) were evaluated. The dose-volume histograms calculated in the PTV with and without corrections for RSE showed only small differences indicating a reduction of the volume of high dose region due to set-up errors. As well, it showed that adequate coverage of the PTV was maintained when RSE was incorporated. Slice-by-slice comparison of the dose distributions revealed differences of up to 5.6%. The incorporation of set-up errors altered the position of the hot spot in the plan. This work demonstrated validity of implementation of the fluence-convolution method to dynamic IMRT Monte Carlo dose calculations. It also showed that accounting for the set-up errors could be essential for correct identification of the value and position of the hot spot

  12. Implementation of random set-up errors in Monte Carlo calculated dynamic IMRT treatment plans

    Science.gov (United States)

    Stapleton, S.; Zavgorodni, S.; Popescu, I. A.; Beckham, W. A.

    2005-02-01

    The fluence-convolution method for incorporating random set-up errors (RSE) into the Monte Carlo treatment planning dose calculations was previously proposed by Beckham et al, and it was validated for open field radiotherapy treatments. This study confirms the applicability of the fluence-convolution method for dynamic intensity modulated radiotherapy (IMRT) dose calculations and evaluates the impact of set-up uncertainties on a clinical IMRT dose distribution. BEAMnrc and DOSXYZnrc codes were used for Monte Carlo calculations. A sliding window IMRT delivery was simulated using a dynamic multi-leaf collimator (DMLC) transport model developed by Keall et al. The dose distributions were benchmarked for dynamic IMRT fields using extended dose range (EDR) film, accumulating the dose from 16 subsequent fractions shifted randomly. Agreement of calculated and measured relative dose values was well within statistical uncertainty. A clinical seven field sliding window IMRT head and neck treatment was then simulated and the effects of random set-up errors (standard deviation of 2 mm) were evaluated. The dose-volume histograms calculated in the PTV with and without corrections for RSE showed only small differences indicating a reduction of the volume of high dose region due to set-up errors. As well, it showed that adequate coverage of the PTV was maintained when RSE was incorporated. Slice-by-slice comparison of the dose distributions revealed differences of up to 5.6%. The incorporation of set-up errors altered the position of the hot spot in the plan. This work demonstrated validity of implementation of the fluence-convolution method to dynamic IMRT Monte Carlo dose calculations. It also showed that accounting for the set-up errors could be essential for correct identification of the value and position of the hot spot.

  13. Bevacizumab treatment in malignant meningioma with additional radiation necrosis. An MRI diffusion and perfusion case study

    Energy Technology Data Exchange (ETDEWEB)

    Bostroem, J.P. [University of Bonn Medical Center, Department of Neurosurgery, Bonn (Germany); MediClin Robert Janker Clinic and MVZ MediClin, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); Seifert, M.; Greschus, S. [University of Bonn Medical Center, Department of Radiology, Bonn (Germany); Schaefer, N.; Herrlinger, U. [University of Bonn Medical Center, Division of Clinical Neurooncology, Department of Neurology, Bonn (Germany); Glas, M. [University of Bonn Medical Center, Division of Clinical Neurooncology, Department of Neurology, Bonn (Germany); University of Bonn Medical Center, Stem Cell Pathologies, Institute of Reconstructive Neurobiology, Bonn (Germany); MediClin Robert Janker Clinic, Clinical Cooperation Unit Neurooncology, Bonn (Germany); Lammering, G. [MediClin Robert Janker Clinic and MVZ MediClin, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); MediClin Robert Janker Clinic, Clinical Cooperation Unit Neurooncology, Bonn (Germany); Heinrich-Heine-University of Duesseldorf, Department of Radiotherapy and Radiation Oncology, Duesseldorf (Germany)

    2014-04-15

    Recently two retrospective cohort studies report efficacy of bevacizumab in patients with recurrent atypical and anaplastic meningioma. Another successful therapeutic option of bevacizumab seems to be treatment of cerebral radiation necrosis. However, the antiangiogenic effects in MRI diffusion and perfusion in meningiomas have not been previously described in detail. The objective of this research was to evaluate the clinical and MR imaging effects of bevacizumab in a malignant meningioma patient harboring additional cerebral radiation necrosis. We report the case of an 80-year-old woman who underwent bevacizumab therapy (5 mg/kg every 2 weeks for 2 months) for treatment of a symptomatic radiation necrosis in malignant meningiomatosis of World Health Organization (WHO) grade III. The patient was closely monitored with MRI including diffusion and perfusion studies. Upon bevacizumab therapy, the clinical situation was well stabilized over a period of 4 months until the patient unfortunately died due to pneumonia/septicemia probably unrelated to bevacizumab therapy. Consecutive MRI demonstrated 4 important aspects: (1) considerable decrease of the contrast medium (CM)-enhanced radiation necrosis, (2) mixed response with respect to the meningiomatosis with stable and predominantly growing tumor lesions, (3) a new diffusion-weighted imaging (DWI) lesion in a CM-enhanced tumor as described in gliomas, which we did not interpret as a response to bevacizumab therapy, and (4) new thrombembolic infarcts, which are a known side-effect of bevacizumab treatment. Bevacizumab is effective in the treatment of radiation necrosis. We could not confirm the potential antitumor effect of bevacizumab in this patient. However, we could describe several new radiographic effects of bevacizumab therapy in malignant meningioma. (orig.) [German] In zwei aktuellen retrospektiven Kohortenstudien konnte eine Wirksamkeit von Bevacizumab bei Patienten mit rezidivierenden atypischen und

  14. SIFT: A method to verify the IMRT fluence delivered during patient treatment using an electronic portal imaging device

    International Nuclear Information System (INIS)

    Vieira, Sandra C.; Dirkx, Maarten L.P.; Heijmen, Ben J.M.; Boer, Hans C.J. de

    2004-01-01

    Purpose: Radiotherapy patients are increasingly treated with intensity-modulated radiotherapy (IMRT) and high tumor doses. As part of our quality control program to ensure accurate dose delivery, a new method was investigated that enables the verification of the IMRT fluence delivered during patient treatment using an electronic portal imaging device (EPID), irrespective of changes in patient geometry. Methods and materials: Each IMRT treatment field is split into a static field and a modulated field, which are delivered in sequence. Images are acquired for both fields using an EPID. The portal dose image obtained for the static field is used to determine changes in patient geometry between the planning CT scan and the time of treatment delivery. With knowledge of these changes, the delivered IMRT fluence can be verified using the portal dose image of the modulated field. This method, called split IMRT field technique (SIFT), was validated first for several phantom geometries, followed by clinical implementation for a number of patients treated with IMRT. Results: The split IMRT field technique allows for an accurate verification of the delivered IMRT fluence (generally within 1% [standard deviation]), even if large interfraction changes in patient geometry occur. For interfraction radiological path length changes of 10 cm, deliberately introduced errors in the delivered fluence could still be detected to within 1% accuracy. Application of SIFT requires only a minor increase in treatment time relative to the standard IMRT delivery. Conclusions: A new technique to verify the delivered IMRT fluence from EPID images, which is independent of changes in the patient geometry, has been developed. SIFT has been clinically implemented for daily verification of IMRT treatment delivery

  15. [Multiple meningiomas].

    Science.gov (United States)

    Terrier, L-M; François, P

    2016-06-01

    Multiple meningiomas (MMs) or meningiomatosis are defined by the presence of at least 2 lesions that appear simultaneously or not, at different intracranial locations, without the association of neurofibromatosis. They present 1-9 % of meningiomas with a female predominance. The occurrence of multiple meningiomas is not clear. There are 2 main hypotheses for their development, one that supports the independent evolution of these tumors and the other, completely opposite, that suggests the propagation of tumor cells of a unique clone transformation, through cerebrospinal fluid. NF2 gene mutation is an important intrinsic risk factor in the etiology of multiple meningiomas and some exogenous risk factors have been suspected but only ionizing radiation exposure has been proven. These tumors can grow anywhere in the skull but they are more frequently observed in supratentorial locations. Their histologic types are similar to unique meningiomas of psammomatous, fibroblastic, meningothelial or transitional type and in most cases are benign tumors. The prognosis of these tumors is eventually good and does not differ from the unique tumors except for the cases of radiation-induced multiple meningiomas, in the context of NF2 or when diagnosed in children where the outcome is less favorable. Each meningioma lesion should be dealt with individually and their multiple character should not justify their resection at all costs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Intraosseous meningioma

    International Nuclear Information System (INIS)

    Daffner, R.H.; Yakulis, R.; Maroon, J.C.

    1998-01-01

    A 71-year-old woman with a long history of slowly progressive proptosis was found to have an intraosseous meningioma of the right sphenoid bone. Radiologically, the lesion resembled fibrous dysplasia. The key to the diagnosis is irregularity of the inner table of the skull. The histologic appearance is characteristic. Intraosseous meningioma is one part of the spectrum of diseases known as primary extraneuraxial meningioma. In this paper we discuss the theories of cellular origin as well as the radiologic differential diagnosis. (orig.)

  17. Domestic comparison of radiation treatment techniques for breast cancer: 3D-CRT, IMRT and VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bo Ram; Yoon, Myong Geun [Dept. of Bio-convergence Engineering, College of Health Science, Korea University, Seoul (Korea, Republic of); Lee, Sun Young [Dept. of Radiation Oncology, Yusung Sun Medical Center, Daejeon (Korea, Republic of)

    2013-09-15

    The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OE (Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ∼ 2.02 Gy, 0.36 ∼ 5.01 Gy, 0.25 ∼ 2.49 Gy, 0.14 ∼ 6.92 Gy, 0.03 ∼ 2.02 Gy, 0.01 ∼ 1.06 Gy, 0.25 ∼ 6.08 Gy, 0.08 ∼ 0.59 Gy, 0.01 ∼ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

  18. IMRT treatment planning based on prioritizing prescription goals

    International Nuclear Information System (INIS)

    Wilkens, Jan J; Alaly, James R; Zakarian, Konstantin; Thorstad, Wade L; Deasy, Joseph O

    2007-01-01

    Determining the 'best' optimization parameters in IMRT planning is typically a time-consuming trial-and-error process with no unambiguous termination point. Recently we and others proposed a goal-programming approach which better captures the desired prioritization of dosimetric goals. Here, individual prescription goals are addressed stepwise in their order of priority. In the first step, only the highest order goals are considered (target coverage and dose-limiting normal structures). In subsequent steps, the achievements of the previous steps are turned into hard constraints and lower priority goals are optimized, in turn, subject to higher priority constraints. So-called 'slip' factors were introduced to allow for slight, clinically acceptable violations of the constraints. Focusing on head and neck cases, we present several examples for this planning technique. The main advantages of the new optimization method are (i) its ability to generate plans that meet the clinical goals, as well as possible, without tuning any weighting factors or dose-volume constraints, and (ii) the ability to conveniently include more terms such as fluence map smoothness. Lower level goals can be optimized to the achievable limit without compromising higher order goals. The prioritized prescription-goal planning method allows for a more intuitive and human-time-efficient way of dealing with conflicting goals compared to the conventional trial-and-error method of varying weighting factors and dose-volume constraints

  19. Scalp meningioma

    Directory of Open Access Journals (Sweden)

    Singh Sunil

    2008-01-01

    Full Text Available Primary extracranial meningiomas occur very rarely. We present a rare case of extracranial meningioma of the transitional variant which was excised satisfactorily. There was no suggestion of any connection to the intracranial compartment or cranial nerves. The underlying galea was uninvolved, suggesting the true extracranial nature of this tumour. This rare diagnosis should nonetheless be kept in the differential diagnosis of scalp tumors.

  20. Dosimetric Comparison Between 3DCRT and IMRT Using Different Multileaf Collimators in the Treatment of Brain Tumors

    International Nuclear Information System (INIS)

    Ding Meisong; Newman, Francis M.S.; Chen Changhu; Stuhr, Kelly; Gaspar, Laurie E.

    2009-01-01

    We investigated the differences between 3-dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT), and the impact of collimator leaf-width on IMRT plans for the treatment of nonspherical brain tumors. Eight patients treated by 3DCRT with Novalis were selected. We developed 3 IMRT plans with different multileaf collimators (Novalis m3, Varian MLC-120, and Varian MLC-80) with the same treatment margins, number of beams, and gantry positions as in the 3DCRT treatment plans. Treatment planning utilized the BrainLAB treatment planning system. For each patient, the dose constraints and optimization parameters remained identical for all plans. The heterogeneity index, the percentage target coverage, critical structures, and normal tissue volumes receiving 50% of the prescription dose were calculated to compare the dosimetric difference. Equivalent uniform dose (EUD) and tumor control probability (TCP) were also introduced to evaluate the radiobiological effect for different plans. We found that IMRT significantly improved the target dose homogeneity compared to the 3DCRT. However, IMRT showed the same radiobiological effect as 3DCRT. For the brain tumors adjacent to (or partially overlapping with) critical structures, IMRT dramatically spared the volume of the critical structures to be irradiated. In IMRT plans, the smaller collimator leaf width could reduce the volume of critical structures irradiated to the 50% level for those partially overlapping with the brain tumors. For relatively large and spherical brain tumors, the smaller collimator leaf widths give no significant benefit

  1. Comparison of step and shoot IMRT treatment plans generated by three inverse treatment planning systems; Comparacion de tratamientos de IMRT estatica generados por tres sistemas de planificacion inversa

    Energy Technology Data Exchange (ETDEWEB)

    Perez Moreno, J. M.; Zucca Aparicio, D.; Fernandez leton, P.; Garcia Ruiz-Zorrilla, J.; Minambres Moro, A.

    2011-07-01

    One of the most important issues of intensity modulated radiation therapy (IMRT) treatments using the step-and-shoot technique is the number of segments and monitor units (MU) for treatment delivery. These parameters depend heavily on the inverse optimization module of the treatment planning system (TPS) used. Three commercial treatment planning systems: CMS XiO, iPlan and Prowess Panther have been evaluated. With each of them we have generated a treatment plan for the same group of patients, corresponding to clinical cases. Dosimetric results, MU calculated and number of segments were compared. Prowess treatment planning system generates plans with a number of segments significantly lower than other systems, while MU are less than a half. It implies important reductions in leakage radiation and delivery time. Degradation in the final dose calculation of dose is very small, because it directly optimizes positions of multileaf collimator (MLC). (Author) 13 refs.

  2. Solution IMRT static of a radiotherapy treatment of breast cancer with lymphangitis

    International Nuclear Information System (INIS)

    Puertolas Hernandez, J. R.; Iriondo Igerabide, U.; Urraca de la Serna, J. M.; Lozano Flores, F. J.; Pino Leon, C.; Larretxa Etxarri, R.

    2013-01-01

    In breast cancer, the planning of treatment with IMRT technique mode static MLC has been efficient to get a perfect union of doses in the skin between the lower limit of the supraclavicular fields and the upper limit of the tangential fields. The technique Planning requires the creation of auxiliary volumes that allow you to manage the particularities inherent to the tangential fields of breast. (Author)

  3. Preferences and Utilities for Health States after Treatment of Olfactory Groove Meningioma: Endoscopic versus Open.

    Science.gov (United States)

    Yao, Christopher M; Kahane, Alyssa; Monteiro, Eric; Gentili, Fred; Zadeh, Gelareh; de Almeida, John R

    2017-08-01

    Objectives  The purpose of this study is to report health utility scores for patients with olfactory groove meningiomas (OGM) treated with either the standard transcranial approach, or the expanded endonasal endoscopic approach. Design  The time trade-off technique was used to derive health utility scores. Setting  Healthy individuals without skull base tumors were surveyed. Main Outcome Measures  Participants reviewed and rated scenarios describing treatment (endoscopic, open, stereotactic radiation, watchful waiting), remission, recurrence, and complications associated with the management of OGMs. Results  There were 51 participants. The endoscopic approach was associated with higher utility scores compared with an open craniotomy approach (0.88 vs. 0.74; p  < 0.001) and watchful waiting (0.88 vs.0.74; p  = 0.002). If recurrence occurred, revision endoscopic resection continued to have a higher utility score compared with revision open craniotomy (0.68; p  = 0.008). On multivariate analysis, older individuals were more likely to opt for watchful waiting ( p  = 0.001), whereas participants from higher income brackets were more likely to rate stereotactic radiosurgery with higher utility scores ( p  = 0.017). Conclusion  The endoscopic approach was associated with higher utility scores than craniotomy for primary and revision cases. The present utilities can be used for future cost-utility analyses.

  4. Multicentre validation of IMRT pre-treatment verification: Comparison of in-house and external audit

    International Nuclear Information System (INIS)

    Jornet, Núria; Carrasco, Pablo; Beltrán, Mercè; Calvo, Juan Francisco; Escudé, Lluís; Hernández, Victor; Quera, Jaume; Sáez, Jordi

    2014-01-01

    Background and purpose: We performed a multicentre intercomparison of IMRT optimisation and dose planning and IMRT pre-treatment verification methods and results. The aims were to check consistency between dose plans and to validate whether in-house pre-treatment verification results agreed with those of an external audit. Materials and methods: Participating centres used two mock cases (prostate and head and neck) for the intercomparison and audit. Compliance to dosimetric goals and total number of MU per plan were collected. A simple quality index to compare the different plans was proposed. We compared gamma index pass rates using the centre’s equipment and methodology to those of an external audit. Results: While for the prostate case, all centres fulfilled the dosimetric goals and plan quality was homogeneous, that was not the case for the head and neck case. The number of MU did not correlate with the plan quality index. Pre-treatment verifications results of the external audit did not agree with those of the in-house measurements for two centres: being within tolerance for in-house measurements and unacceptable for the audit or the other way round. Conclusions: Although all plans fulfilled dosimetric constraints, plan quality is highly dependent on the planner expertise. External audits are an excellent tool to detect errors in IMRT implementation and cannot be replaced by intercomparison using results obtained by centres

  5. Maximizing dosimetric benefits of IMRT in the treatment of localized prostate cancer through multicriteria optimization planning

    International Nuclear Information System (INIS)

    Wala, Jeremiah; Craft, David; Paly, Jon; Zietman, Anthony; Efstathiou, Jason

    2013-01-01

    We examine the quality of plans created using multicriteria optimization (MCO) treatment planning in intensity-modulated radiation therapy (IMRT) in treatment of localized prostate cancer. Nine random cases of patients receiving IMRT to the prostate were selected. Each case was associated with a clinically approved plan created using Corvus. The cases were replanned using MCO-based planning in RayStation. Dose-volume histogram data from both planning systems were presented to 2 radiation oncologists in a blinded evaluation, and were compared at a number of dose-volume points. Both physicians rated all 9 MCO plans as superior to the clinically approved plans (p −5 ). Target coverage was equivalent (p = 0.81). Maximum doses to the prostate and bladder and the V50 and V70 to the anterior rectum were reduced in all MCO plans (p<0.05). Treatment planning time with MCO took approximately 60 minutes per case. MCO-based planning for prostate IMRT is efficient and produces high-quality plans with good target homogeneity and sparing of the anterior rectum, bladder, and femoral heads, without sacrificing target coverage

  6. Maximizing dosimetric benefits of IMRT in the treatment of localized prostate cancer through multicriteria optimization planning

    Energy Technology Data Exchange (ETDEWEB)

    Wala, Jeremiah; Craft, David [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Paly, Jon [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Zietman, Anthony [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Efstathiou, Jason, E-mail: jefstathiou@partners.org [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2013-10-01

    We examine the quality of plans created using multicriteria optimization (MCO) treatment planning in intensity-modulated radiation therapy (IMRT) in treatment of localized prostate cancer. Nine random cases of patients receiving IMRT to the prostate were selected. Each case was associated with a clinically approved plan created using Corvus. The cases were replanned using MCO-based planning in RayStation. Dose-volume histogram data from both planning systems were presented to 2 radiation oncologists in a blinded evaluation, and were compared at a number of dose-volume points. Both physicians rated all 9 MCO plans as superior to the clinically approved plans (p<10{sup −5}). Target coverage was equivalent (p = 0.81). Maximum doses to the prostate and bladder and the V50 and V70 to the anterior rectum were reduced in all MCO plans (p<0.05). Treatment planning time with MCO took approximately 60 minutes per case. MCO-based planning for prostate IMRT is efficient and produces high-quality plans with good target homogeneity and sparing of the anterior rectum, bladder, and femoral heads, without sacrificing target coverage.

  7. Experience in the treatment of IMRT in prostate cancer. Planning, dosimetry and quality control

    International Nuclear Information System (INIS)

    Gomez Barrado, A.; Garcia Vicente, F.; Fernandez Bedoya, V.; Bermudez Luna, R.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2011-01-01

    The aim of this study is to review the treatment of prostate cancer at our center. A description of the entire procedure, involving clinical dosimetry, and procedures for verification of treatment, including physical dosimetry and parallel computing system MSure (Standard Imaging, Inc., Middleton) as part of these procedures. This system is based on the model published by trifuente Yang et al. (Yang et al. 2002) for testing treatments regarding the number of monitor unit (MU) given. In addition, this software has a module for the testing of treatments for intensity modulated radiotherapy (IMRT), which will be analyzed in this study.

  8. Solution IMRT static of a radiotherapy treatment of breast cancer with lymphangitis; Solucion IMRT estatica de un tratamiento radioterapico del cancer de mama con linfangitis carcinomatosa cutanea

    Energy Technology Data Exchange (ETDEWEB)

    Puertolas Hernandez, J. R.; Iriondo Igerabide, U.; Urraca de la Serna, J. M.; Lozano Flores, F. J.; Pino Leon, C.; Larretxa Etxarri, R.

    2013-07-01

    In breast cancer, the planning of treatment with IMRT technique mode static MLC has been efficient to get a perfect union of doses in the skin between the lower limit of the supraclavicular fields and the upper limit of the tangential fields. The technique Planning requires the creation of auxiliary volumes that allow you to manage the particularities inherent to the tangential fields of breast. (Author)

  9. Evaluation of IMRT plans for prostate treatment using energies of 6 MV and 15 MV

    International Nuclear Information System (INIS)

    Guimaraes, Lucas Francisco C.; Silva, Murilo C. da; Silveira, Paula J.; Flosi, Adriana A.; Boccaletti, Karina W.

    2013-01-01

    This study aims to evaluate and compare radiotherapy plans with intensity-modulated radiation therapy (IMRT) for prostate cancer treatments optimized for photon energies of 6 MV and 15 MV. We retrospectively evaluated 29 patients with prostate cancer, planned with IMRT technique with prescribed dose of 78 Gy. The initial plan was done for the two photon energies, keeping the same optimization parameters and comparing maximum, minimum and modal PTV doses, conformity and homogeneity indexes, dose gradients, isodoses volumes of 30, 40, 50, 60, and 70 Gy, and the total number of monitor units. It was found that the plans are equivalent regarding higher isodose volumes, conformity and homogeneity indexes, maximum, minimum and modal PTV doses. However, for 6 MV plans there was a considerable increase in both number of monitor units and volume lower isodose volumes, especially the 30 Gy. (author)

  10. Dosimetry and planning audit of IMRT prostate treatment in the Czech Republic with a pelvic phantom

    International Nuclear Information System (INIS)

    Koniarova, I.; Horakova, I.; Dufek, V.; Kotik, L.

    2014-01-01

    In 2013, the national end-to-end audit of IMRT prostate treatment with a pelvic phantom has been carried out in the Czech Republic. It has been performed by the NRPI on site and the participation was voluntary. All departments (17) where IMRT is used for prostate treatment participated. In total, 21 plans have been evaluated. Phantom with clearly defined structures that were the same for all departments has been used. There was a dosimetric and a planning part of the audit. The determination of absorbed doses with ionization chambers placed in the PTV and in the rectum and the comparison to the planned doses was performed. Planar dose distribution was verified with gafchromic film. Majority of departments were able to deliver the IMRT plan successfully. The dose to PTV measured with ionization chamber in the phantom exceeded tolerance level of 3% in 4 cases. The mean of measured to planned dose for PTV was 0.991 ± 0.004. In one case, the tolerance level for planar dose was significantly exceeded. Constraints used for planning, volumes calculation, and DVHs were analyzed. (authors)

  11. Development of independent MU/treatment time verification algorithm for non-IMRT treatment planning: A clinical experience

    Science.gov (United States)

    Tatli, Hamza; Yucel, Derya; Yilmaz, Sercan; Fayda, Merdan

    2018-02-01

    The aim of this study is to develop an algorithm for independent MU/treatment time (TT) verification for non-IMRT treatment plans, as a part of QA program to ensure treatment delivery accuracy. Two radiotherapy delivery units and their treatment planning systems (TPS) were commissioned in Liv Hospital Radiation Medicine Center, Tbilisi, Georgia. Beam data were collected according to vendors' collection guidelines, and AAPM reports recommendations, and processed by Microsoft Excel during in-house algorithm development. The algorithm is designed and optimized for calculating SSD and SAD treatment plans, based on AAPM TG114 dose calculation recommendations, coded and embedded in MS Excel spreadsheet, as a preliminary verification algorithm (VA). Treatment verification plans were created by TPSs based on IAEA TRS 430 recommendations, also calculated by VA, and point measurements were collected by solid water phantom, and compared. Study showed that, in-house VA can be used for non-IMRT plans MU/TT verifications.

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

    CERN Document Server

    Meyer, JL

    2011-01-01

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

  13. Outcomes and Patterns of Failure for Grade 2 Meningioma Treated With Reduced-Margin Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Press, Robert H. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Prabhu, Roshan S., E-mail: roshansprabhu@gmail.com [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Appin, Christina L.; Brat, Daniel J. [Department of Pathology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Shu, Hui-Kuo G. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Hadjipanayis, Constantinos; Olson, Jeffrey J.; Oyesiku, Nelson M. [Department of Neurosurgery, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Curran, Walter J.; Crocker, Ian [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)

    2014-04-01

    Purpose: The purpose of this study was to evaluate intracranial control and patterns of local recurrence (LR) for grade 2 meningiomas treated with intensity modulated radiation therapy (IMRT) with limited total margin expansions of ≤1 cm. Methods and Materials: We reviewed records of patients with a neuropathological diagnosis of grade 2 meningioma who underwent IMRT at our institution between 2002 and 2012. Actuarial rates were determined by the Kaplan-Meier method from the end of RT. LR was defined as in-field if ≥90% of the recurrence was within the prescription isodose, out-of-field (marginal) if ≥90% was outside of the prescription isodose, and both if neither criterion was met. Results: Between 2002 and 2012, a total of 54 consecutive patients underwent IMRT for grade 2 meningioma. Eight of these patients had total initial margins >1 cm and were excluded, leaving 46 patients for analysis. The median imaging follow-up period was 26.2 months (range, 7-107 months). The median dose for fractionated IMRT was 59.4 Gy (range, 49.2-61.2 Gy). Median clinical target volume (CTV), planning target volume (PTV), and total margin expansion were 0.5 cm, 0.3 cm, and 0.8 cm, respectively. LR occurred in 8 patients (17%), with 2-year and 3-year actuarial local control (LC) of 92% and 74%, respectively. Six of 8 patients (85%) had a known pattern of failure. Five patients (83%) had in-field LR; no patients had marginal LR; and 1 patient (17%) had both. Conclusions: The use of IMRT to treat grade 2 meningiomas with total initial margins (CTV + PTV) ≤1 cm did not appear to compromise outcomes or increase marginal failures compared with other modern retrospective series. Of the 46 patients who had margins ≤1 cm, none experienced marginal failure only. These results demonstrate efficacy and low risk of marginal failure after IMRT treatment of grade 2 meningiomas with reduced margins, warranting study within a prospective clinical trial.

  14. Kidney-Sparing Methods for Extended-Field Intensity-Modulated Radiotherapy (EF-IMRT) in Cervical Carcinoma Treatment.

    Science.gov (United States)

    Kunogi, Hiroaki; Yamaguchi, Nanae; Terao, Yasuhisa; Sasai, Keisuke

    2016-01-01

    Coplanar extended-field intensity-modulated radiation therapy (EF-IMRT) targeting the whole-pelvic and para-aortic lymph nodes in patients with advanced cervical cancer results in impaired creatinine clearance. An improvement in renal function cannot be expected unless low-dose (approximately 10 Gy) kidney exposure is reduced. The dosimetric method should be considered during EF-IMRT planning to further reduce low-dose exposure to the kidneys. To assess the usefulness of non-coplanar EF-IMRT with kidney-avoiding beams to spare the kidneys during cervical carcinoma treatment in dosimetric analysis between non-coplanar and coplanar EF-IMRT, we compared the doses of the target organ and organs at risk, including the kidney, in 10 consecutive patients. To estimate the influence of EFRT on renal dysfunction, creatinine clearance values after treatment were also examined in 18 consecutive patients. Of these 18 patients, 10 patients who were included in the dosimetric analysis underwent extended field radiation therapy (EFRT) with concurrent chemotherapy, and eight patients underwent whole-pelvis radiation therapy with concurrent chemotherapy to treat cervical carcinoma between April 2012 and March 2015 at our institution. In the dosimetric analysis, non-coplanar EF-IMRT was effective at reducing low-dose (approximately 10 Gy) exposure to the kidneys, thus maintaining target coverage and sparing other organs at risk, such as the small bowel, rectum, and bladder, compared with coplanar EF-IMRT. Renal function in all 10 patients who underwent EFRT, including coplanar EF-IMRT (with kidney irradiation), was low after treatment, and differed significantly from that of the eight patients who underwent WPRT (no kidney irradiation) 6 months after the first day of treatment (P = 0.005). In conclusion, non-coplanar EF-IMRT should be considered in patients with advanced cervical cancer, particularly in patients with a long life expectancy or with pre-existing renal dysfunction.

  15. Volumetric changes and clinical outcome for petroclival meningiomas after primary treatment with Gamma Knife radiosurgery.

    Science.gov (United States)

    Sadik, Zjiwar H A; Lie, Suan Te; Leenstra, Sieger; Hanssens, Patrick E J

    2018-01-26

    OBJECTIVE Petroclival meningiomas (PCMs) can cause devastating clinical symptoms due to mass effect on cranial nerves (CNs); thus, patients harboring these tumors need treatment. Many neurosurgeons advocate for microsurgery because removal of the tumor can provide relief or result in symptom disappearance. Gamma Knife radiosurgery (GKRS) is often an alternative for surgery because it can cause tumor shrinkage with improvement of symptoms. This study evaluates qualitative volumetric changes of PCM after primary GKRS and its impact on clinical symptoms. METHODS The authors performed a retrospective study of patients with PCM who underwent primary GKRS between 2003 and 2015 at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg, the Netherlands. This study yields 53 patients. In this study the authors concentrate on qualitative volumetric tumor changes, local tumor control rate, and the effect of the treatment on trigeminal neuralgia (TN). RESULTS Local tumor control was 98% at 5 years and 93% at 7 years (Kaplan-Meier estimates). More than 90% of the tumors showed regression in volume during the first 5 years. The mean volumetric tumor decrease was 21.2%, 27.1%, and 31% at 1, 3, and 6 years of follow-up, respectively. Improvement in TN was achieved in 61%, 67%, and 70% of the cases at 1, 2, and 3 years of follow-up, respectively. This was associated with a mean volumetric tumor decrease of 25% at the 1-year follow-up to 32% at the 3-year follow-up. CONCLUSIONS GKRS for PCMs yields a high tumor control rate with a low incidence of neurological deficits. Many patients with TN due to PCM experienced improvement in TN after radiosurgery. GKRS achieves significant volumetric tumor decrease in the first years of follow-up and thereafter.

  16. MRI-based treatment planning for radiotherapy: Dosimetric verification for prostate IMRT

    International Nuclear Information System (INIS)

    Chen, Lili; Price, Robert A.; Wang Lu; Li Jinsheng; Qin Lihong; McNeeley, Shawn; Ma, C.-M. Charlie; Freedman, Gary M.; Pollack, Alan

    2004-01-01

    Purpose: Magnetic resonance (MR) and computed tomography (CT) image fusion with CT-based dose calculation is the gold standard for prostate treatment planning. MR and CT fusion with CT-based dose calculation has become a routine procedure for intensity-modulated radiation therapy (IMRT) treatment planning at Fox Chase Cancer Center. The use of MRI alone for treatment planning (or MRI simulation) will remove any errors associated with image fusion. Furthermore, it will reduce treatment cost by avoiding redundant CT scans and save patient, staff, and machine time. The purpose of this study is to investigate the dosimetric accuracy of MRI-based treatment planning for prostate IMRT. Methods and materials: A total of 30 IMRT plans for 15 patients were generated using both MRI and CT data. The MRI distortion was corrected using gradient distortion correction (GDC) software provided by the vendor (Philips Medical System, Cleveland, OH). The same internal contours were used for the paired plans. The external contours were drawn separately between CT-based and MR imaging-based plans to evaluate the effect of any residual distortions on dosimetric accuracy. The same energy, beam angles, dose constrains, and optimization parameters were used for dose calculations for each paired plans using a treatment optimization system. The resulting plans were compared in terms of isodose distributions and dose-volume histograms (DVHs). Hybrid phantom plans were generated for both the CT-based plans and the MR-based plans using the same leaf sequences and associated monitor units (MU). The physical phantom was then irradiated using the same leaf sequences to verify the dosimetry accuracy of the treatment plans. Results: Our results show that dose distributions between CT-based and MRI-based plans were equally acceptable based on our clinical criteria. The absolute dose agreement for the planning target volume was within 2% between CT-based and MR-based plans and 3% between measured dose

  17. Beam angle selection for intensity-modulated radiotherapy (IMRT) treatment of unresectable pancreatic cancer: are noncoplanar beam angles necessary?

    Science.gov (United States)

    Chang, D S; Bartlett, G K; Das, I J; Cardenes, H R

    2013-09-01

    External beam radiation therapy with concurrent chemotherapy (CRT) is widely used for the treatment of unresectable pancreatic cancer. Noncoplanar (NCP) 3D conformal radiotherapy (3DCRT) and coplanar (CP) IMRT have been reported to lower the radiation dose to organs at risk (OARs). The purpose of this article is to examine the utility of noncoplanar beam angles in IMRT for the management of pancreatic cancer. Sixteen patients who were treated with CRT for unresectable adenocarcinoma of the pancreatic head or neck were re-planned using CP and NCP beams in 3DCRT and IMRT with the Varian Eclipse treatment planning system. Compared to CP IMRT, NCP IMRT had similar target coverage with slightly increased maximum point dose, 5,799 versus 5,775 cGy (p = 0.008). NCP IMRT resulted in lower mean kidney dose, 787 versus 1,210 cGy (p kidney dose, but did not improve other dose-volume criteria. The use of NCP beam angles is preferred only in patients with risk factors for treatment-related kidney dysfunction.

  18. Hypofractionated high-energy proton-beam irradiation is an alternative treatment for WHO grade I meningiomas.

    Science.gov (United States)

    Vlachogiannis, Pavlos; Gudjonsson, Olafur; Montelius, Anders; Grusell, Erik; Isacsson, Ulf; Nilsson, Kristina; Blomquist, Erik

    2017-12-01

    Radiation treatment is commonly employed in the treatment of meningiomas. The aim of this study was to evaluate the effectiveness and safety of hypofractionated high-energy proton therapy as adjuvant or primary treatment for WHO grade I meningiomas. A total of 170 patients who received irradiation with protons for grade I meningiomas between 1994 and 2007 were included in the study. The majority of the tumours were located at the skull base (n = 155). Eighty-four patients were treated post subtotal resection, 42 at tumour relapse and 44 with upfront radiotherapy after diagnosis based on the typical radiological image. Irradiation was given in a hypofractionated fashion (3-8 fractions, usually 5 or 6 Gy) with a mean dose of 21.9 Gy (range, 14-46 Gy). All patients were planned for follow-up with clinical controls and magnetic resonance imaging scans at 6 months and 1, 2, 3, 5, 7 and 10 years after treatment. The median follow-up time was 84 months. Age, gender, tumour location, Simpson resection grade and target volume were assessed as possible prognostic factors for post-irradiation tumour progression and radiation related complications. The actuarial 5- and 10-year progression-free survival rates were 93% and 85% respectively. Overall mortality rate was 13.5%, while disease-specific mortality was 1.7% (3/170 patients). Older patients and patients with tumours located in the middle cranial fossa had a lower risk for tumour progression. Radiation-related complications were seen in 16 patients (9.4%), with pituitary insufficiency being the most common. Tumour location in the anterior cranial fossa was the only factor that significantly increased the risk of complications. Hypofractionated proton-beam radiation therapy may be used particularly in the treatment of larger World Health Organisation grade I meningiomas not amenable to total surgical resection. Treatment is associated with high rates of long-term tumour growth control and acceptable risk for

  19. Effect of position of blades in the treatment of IMRT

    International Nuclear Information System (INIS)

    Perez Azorin, J. F.; Ramos Garcia, L. I.; Ortiz de Zarate Vivanco, R.; Trueba Garayo, I.; Cacicedo, J.; Hoyo, O. del

    2013-01-01

    This paper presents a method of calculation of the positions of each blade measures during treatment for all segments and the subsequent reconstruction of these positions in the planning system on the patient's physical and anatomical data. (Author)

  20. Long-Term Outcomes of Stereotactic Radiosurgery for Treatment of Cavernous Sinus Meningiomas

    International Nuclear Information System (INIS)

    Santos, Marcos Antonio dos; Bustos Pérez de Salcedo, José; Gutiérrez Diaz, José Angel; Calvo, Felipe A.; Samblás, José; Marsiglia, Hugo; Sallabanda, Kita

    2011-01-01

    Purpose: Patients with cavernous sinus meningiomas (CSM) have an elevated risk of surgical morbidity and mortality. Recurrence is often observed after partial resection. Stereotactic radiosurgery (SRS), either alone or combined with surgery, represents an important advance in CSM management, but long-term results are lacking. Methods and Materials: A total of 88 CSM patients, treated from January 1991 to December 2005, were retrospectively reviewed. The mean follow-up was 86.8 months (range, 17.1–179.4 months). Among the patients, 22 were followed for more than 10 years. There was a female predominance (84.1%). The age varied from 16 to 90 years (mean, 51.6). In all, 47 patients (53.4%) received SRS alone, and 41 patients (46.6%) had undergone surgery before SRS. A dose of 14 Gy was prescribed to isodose curves from 50% to 90%. In 25 patients (28.4%), as a result of the proximity to organs at risk, the prescribed dose did not completely cover the target. Results: After SRS, 65 (73.8%) patients presented with tumor volume reduction; 14 (15.9%) remained stable, and 9 (10.2%) had tumor progression. The progression-free survival was 92.5% at 5 years, and 82.5% at 10 years. Age, sex, maximal diameter of the treated tumor, previous surgery, and complete target coverage did not show significant associations with prognosis. Among the 88 treated patients, 17 experienced morbidity that was related to SRS, and 6 of these patients spontaneously recovered. Conclusions: SRS is an effective and safe treatment for CSM, feasible either in the primary or the postsurgical setting. Incomplete coverage of the target did not worsen outcomes. More than 80% of the patients remained free of disease progression during long-term follow-up.

  1. Long-Term Outcomes of Stereotactic Radiosurgery for Treatment of Cavernous Sinus Meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcos Antonio dos, E-mail: marcosrxt@gmail.com [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Bustos Perez de Salcedo, Jose; Gutierrez Diaz, Jose Angel [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Neurosurgery Department, Sanatorio San Francisco de Asis, Madrid (Spain); Calvo, Felipe A. [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Department of Oncology, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Samblas, Jose [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Neurosurgery Department, Sanatorio San Francisco de Asis, Madrid (Spain); Marsiglia, Hugo [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Sallabanda, Kita [Radiotherapy Department, Instituto Madrileno de Oncologia/Grupo IMO, Madrid (Spain); Neurosurgery Department, Sanatorio San Francisco de Asis, Madrid (Spain)

    2011-12-01

    Purpose: Patients with cavernous sinus meningiomas (CSM) have an elevated risk of surgical morbidity and mortality. Recurrence is often observed after partial resection. Stereotactic radiosurgery (SRS), either alone or combined with surgery, represents an important advance in CSM management, but long-term results are lacking. Methods and Materials: A total of 88 CSM patients, treated from January 1991 to December 2005, were retrospectively reviewed. The mean follow-up was 86.8 months (range, 17.1-179.4 months). Among the patients, 22 were followed for more than 10 years. There was a female predominance (84.1%). The age varied from 16 to 90 years (mean, 51.6). In all, 47 patients (53.4%) received SRS alone, and 41 patients (46.6%) had undergone surgery before SRS. A dose of 14 Gy was prescribed to isodose curves from 50% to 90%. In 25 patients (28.4%), as a result of the proximity to organs at risk, the prescribed dose did not completely cover the target. Results: After SRS, 65 (73.8%) patients presented with tumor volume reduction; 14 (15.9%) remained stable, and 9 (10.2%) had tumor progression. The progression-free survival was 92.5% at 5 years, and 82.5% at 10 years. Age, sex, maximal diameter of the treated tumor, previous surgery, and complete target coverage did not show significant associations with prognosis. Among the 88 treated patients, 17 experienced morbidity that was related to SRS, and 6 of these patients spontaneously recovered. Conclusions: SRS is an effective and safe treatment for CSM, feasible either in the primary or the postsurgical setting. Incomplete coverage of the target did not worsen outcomes. More than 80% of the patients remained free of disease progression during long-term follow-up.

  2. Stereotactic intensity-modulated radiation therapy (IMRT) and inverse treatment planning for advanced pleural mesothelioma. Feasibility and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Muenter, M.W.; Thilmann, C.; Hof, H.; Debus, J. [Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (dkfz), Heidelberg (Germany); Nill, S.; Hoess, A.; Partridge, M. [Dept. of Medical Physics, German Cancer Research Center (dkfz), Heidelberg (Germany); Haering, P. [Dept. of Central Dosimetry, German Cancer Research Center (dkfz), Heidelberg (Germany); Manegold, C. [Dept. of Medical Oncology/Internal Medicine, Thoraxklinik Heidelberg gGmbH, Heidelberg (Germany); Wannenmacher, M. [Dept. of Clinical Radiology, Univ. of Heidelberg, Heidelberg (Germany)

    2003-08-01

    Background and Purpose: Complex-shaped malignant pleural mesotheliomas (MPMs) with challenging volumes are extremely difficult to treat by conventional radiotherapy due to tolerance doses of the surrounding normal tissue. In a feasibility study, we evaluated if inversely planned stereotactic intensity-modulated radiation therapy (IMRT) could be applied in the treatment of MPM. Patients and Methods: Eight patients with unresectable lesions were treated after failure of chemotherapy. All patients were positioned using noninvasive patient fixation techniques which can be attached to the applied extracranial stereotactic system. Due to craniocaudal extension of the tumor, it was necessary to develop a special software attached to the inverse planning program KonRad, which can connect two inverse treatment plans and consider the applied dose of the first treatment plan in the area of the matchline of the second treatment plan. Results: Except for one patient, in whom radiotherapy was canceled due to abdominal metastasis, treatment could be completed in all patients and was well tolerated. Median survival after diagnosis was 20 months and after IMRT 6.5 months. Therefore, both the 1-year actuarial overall survival from the start of radiotherapy and the 2-year actuarial overall survival since diagnosis were 28%. IMRT did not result in clinically significant acute side effects. By using the described inverse planning software, over- or underdosage in the region of the field matchline could be prevented. Pure treatment time ranged between 10 and 21 min. Conclusion: This study showed that IMRT is feasible in advanced unresectable MPM. The presented possibilities of stereotactic IMRT in the treatment of MPM will justify the evaluation of IMRT in early-stage pleural mesothelioma combined with chemotherapy in a study protocol, in order to improve the outcome of these patients. Furthermore, dose escalation should be possible by using IMRT. (orig.)

  3. Dosimetric pre-treatment verification of IMRT using an EPID; clinical experience

    International Nuclear Information System (INIS)

    Zijtveld, Mathilda van; Dirkx, Maarten L.P.; Boer, Hans C.J. de; Heijmen, Ben J.M.

    2006-01-01

    Background and purpose: In our clinic a QA program for IMRT verification, fully based on dosimetric measurements with electronic portal imaging devices (EPID), has been running for over 3 years. The program includes a pre-treatment dosimetric check of all IMRT fields. During a complete treatment simulation at the linac, a portal dose image (PDI) is acquired with the EPID for each patient field and compared with a predicted PDI. In this paper, the results of this pre-treatment procedure are analysed, and intercepted errors are reported. An automated image analysis procedure is proposed to limit the number of fields that need human intervention in PDI comparison. Materials and methods: Most of our analyses are performed using the γ index with 3% local dose difference and 3 mm distance to agreement as reference values. Scalar parameters are derived from the γ values to summarize the agreement between measured and predicted 2D PDIs. Areas with all pixels having γ values larger than one are evaluated, making decisions based on clinically relevant criteria more straightforward. Results: In 270 patients, the pre-treatment checks revealed four clinically relevant errors. Calculation of statistics for a group of 75 patients showed that the patient-averaged mean γ value inside the field was 0.43 ± 0.13 (1 SD) and only 6.1 ± 6.8% of pixels had a γ value larger than one. With the proposed automated image analysis scheme, visual inspection of images can be avoided in 2/3 of the cases. Conclusion: EPIDs may be used for high accuracy and high resolution routine verification of IMRT fields to intercept clinically relevant dosimetric errors prior to the start of treatment. For the majority of fields, PDI comparison can fully rely on an automated procedure, avoiding excessive workload

  4. Matching IMRT fields with static photon field in the treatment of head-and-neck cancer

    International Nuclear Information System (INIS)

    Li, Jonathan G.; Liu, Chihray; Kim, Siyong; Amdur, Robert J.; Palta, Jatinder R.

    2005-01-01

    Radiation treatment with intensity-modulated radiation therapy (IMRT) for head-and-neck cancer usually involves treating the superior aspects of the target volume with intensity-modulated (IM) fields, and the inferior portion of the target volume (the low neck nodes) with a static anterior-posterior field (commonly known as the low anterior neck, or LAN field). A match line between the IM and the LAN fields is created with possibly large dose inhomogeneities, which are clinically undesirable. We propose a practical method to properly match these fields with minimal dependence on patient setup errors. The method requires mono-isocentric setup of the IM and LAN fields with half-beam blocks as defined by the asymmetric jaws. The inferior jaws of the IM fields, which extend ∼1 cm inferiorly past the isocenter, are changed manually before patient treatment, so that they match the superior jaw of the LAN field at the isocenter. The matching of these fields therefore does not depend on the particular treatment plan of IMRT and depends only on the matching of the asymmetric jaws. Measurements in solid water phantom were performed to verify the field-matching technique. Dose inhomogeneities of less than 5% were obtained in the match-line region. Feathering of the match line is done twice during the course of a treatment by changing the matching jaw positions superiorly at 3-mm increments each time, which further reduces the dose inhomogeneity. Compared to the method of including the lower neck nodes in the IMRT fields, the field-matching technique increases the delivery efficiency and significantly reduces the total treatment time

  5. Fractionated radiation therapy in the treatment of intracranial meningiomas: local control, functional efficacy, and tolerance in 91 patients

    International Nuclear Information System (INIS)

    Maire, Jean-Philippe; Caudry, Michel; Guerin, Jean; Celerier, Denis; San Galli, Francois; Causse, Nicole; Trouette, Renaud; Dautheribes, Michel

    1995-01-01

    Purpose: To evaluate efficacy and tolerance of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. Methods and Materials: From January 1981 to September 1993, 91 patients with intracranial meningiomas were treated with fractionated RT. Indications were as follows: (a) incomplete surgical resection, 29 patients; (b) tumor recurrences without considering the amount of the second resection, if performed, 14 patients; (c) completely excised angioblastic, aggressive benign, and anaplastic tumors, 8 patients; (d) medically inoperable and basilar tumors where operation would involve considerable danger or permanent neurological damage, 44 patients. Most patients were irradiated with 6 to 9 MV photon beams. A three- to four-field technique with coned-down portals was used. Doses were calculated on the 95% isodose and were given 5 days a week for a median total dose of 52 Gy (1.80 Gy/fraction). Results: Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent, but there were six late delayed injuries. Tumor recurrences occurred in six cases. Six patients died from their tumor or RT complications, 19 from nontumoral reasons. Three, 5- and 10-year survival rates were 82, 71, and 40%, respectively. The most significant prognostic factor was age: 5-year survival rate was 86% for patients less than 65 years and 37% for patients more than 65. However, there were no differences in recurrence-free survival rates between patients younger than 65 and the oldest ones. Of 60 symptomatic patients with neurological deficits, 43 had neurological improvement (72%), beginning in some cases within 15 to 20 days after starting RT. Conclusion: These results reassess the role of fractionated RT in the treatment of meningiomas, and stress on its efficacy, especially on cranial nerves palsies, without severe toxicity in most cases

  6. Dosimetric impact of interplay effect in lung IMRT and VMAT treatment using in-house dynamic thorax phantom

    International Nuclear Information System (INIS)

    Mukhlisin; Pawiro, S A

    2016-01-01

    Tumor motion due to patient's respiratory is a significant problem in radiotherapy treatment of lung cancer. The purpose of this project is to study the interplay effect through dosimetry verification between the calculated and delivered dose, as well as the dosimetric impact of leaf interplay with breathing-induced tumor motion in IMRT and VMAT treatment. In this study, a dynamic thorax phantom was designed and constructed for dosimetry measurement. The phantom had a linear sinusoidal tumor motion toward superior-inferior direction with variation of amplitudes and periods. TLD-100 LiF:Mg,Ti and Gafchromic EBT2 film were used to measure dose in the midpoint target and the spinal cord. The IMRT and VMAT treatment had prescription dose of 200 cGy per fraction. The dosimetric impact due to interplay effect during IMRT and VMAT treatment were resulted in the range of 0.5% to -6.6% and 0.9% to -5.3% of target dose reduction, respectively. Meanwhile, mean dose deviation of spinal cord in IMRT and VMAT treatment were around 1.0% to -6.9% and 0.9% to -6.3%, respectively. The results showed that if respiratory management technique were not implemented, the presence of lung tumor motion during dose delivery in IMRT and VMAT treatment causes dose discrepancies inside tumor volume. (paper)

  7. A project proposal for implementing intensity modulated radiotherapy (IMRT) for treatment of head and neck tumors

    International Nuclear Information System (INIS)

    Napoles Morales, Misleidy; Garcia Yip, Fernando; Rodriguez Machado, Jorge; Yanes Lopez, Yaima; Pomares Gomez, Yenes; Mena, Yailen

    2009-01-01

    Malignant tumors located in the structures of the head and neck, excluding the skull and its contents, constitute 10% of all cancers, remains the most frequent locations, which correspond to the oral cavity between 40 to 60%. Diagnosed between 60 to 80% in early stages and a 15 to 30% in more advanced forms of the disease. Radiotherapy and surgery are the essential therapeutic tools in the treatment of these tumors planning processes and administration of radiotherapy treatments currently in a situation of rapid and radical change. Since the beginning of radiotherapy to this day the greatest advances in treatment have been linked to a better definition of the tumor irradiation thus get a reduced dose in healthy tissue. The use of radiation, can be severe sequelae affecting quality of life of the patient, organs at risk receiving high dose and advanced technique of IMRT treatment planning and allows treatments shaped fields, especially when the target of radiation is irregular, with fewer side effects by limiting the dose in the tumor tissues and organs at risk and to allow us to increase the doses in the tumor. So we decided to develop a protocol for the implementation of IMRT, taking into account that we have the appropriate equipment, trained staff to develop this technique. (Author)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  9. The Importance of the Conformality, Heterogeneity, and Gradient Indices in Evaluating Gamma Knife Radiosurgery Treatment Plans for Intracranial Meningiomas

    International Nuclear Information System (INIS)

    Balagamwala, Ehsan H.; Suh, John H.; Barnett, Gene H.; Khan, Mohammad K.; Neyman, Gennady; Cai, Rong S.; Vogelbaum, Michael A.; Novak, Eric; Chao, Samuel T.

    2012-01-01

    Purpose: To investigate the relationship between the conformality index (CIn), heterogeneity index (HIn), and gradient index (GIn) and the development of toxicity in patients treated with Gamma Knife radiosurgery (GKRS) for intracranial meningiomas. Methods and Materials: Treatment records of patients treated from 1997 to 2009 with at least 6 months of follow-up were reviewed. The following parameters were collected: CIn, HIn, GIn (ratio of the volume receiving half the prescription isodose to the volume receiving the full prescription isodose), brainstem (BS) maximum dose (MD), BS volume receiving ≥12 Gy (V12), optic apparatus (OA) MD, OA V8 Gy, OA V10, number of isocenters, number of isocenters outside target volume, and the occurrence of six toxicities. Univariate and multivariate logistic regression modeling were used for analysis. Results: This study included 145 patients (148 meningiomas) with a median follow-up time of 27 months (range, 6–113.9 months). The majority of meningiomas were located in the skull base (53%). The median prescription dose was 13 Gy (range, 10–24 Gy) to the 51.50% (range, 50–92%) isodose. A lower HIn was correlated with a higher GIn (p = 0.007). CIn was not associated with any toxicity. Higher HIn was associated with the development of dizziness (odds ratio [OR] 1.9; p = 0.02), whereas a lower GIn was associated with motor deficits (OR 0.38; p = 0.04) and auditory changes (OR 0.59; p = 0.04). The OA MD, V8, and V12 were not associated with visual changes, but visual changes were associated with a higher number of isocenters outside the target volume (OR 1.93; p = 0.07). BS V12 was correlated with the development of auditory changes (OR 1.05; p = 0.05), whereas patients with higher BS MD tended to have increased toxicity. Conclusions: Close attention must be paid to all three indices (CIn, HIn, GIn) when optimal treatment plans are determined. We recommend that the target CIn should be ≤2.0, the HIn ≤2.0, and the GIn ≥3

  10. An investigation of PRESAGE® 3D dosimetry for IMRT and VMAT radiation therapy treatment verification

    International Nuclear Information System (INIS)

    Jackson, Jake; Juang, Titania; Oldham, Mark; Adamovics, John

    2015-01-01

    The purpose of this work was to characterize three formulations of PRESAGE ® dosimeters (DEA-1, DEA-2, and DX) and to identify optimal readout timing and procedures for accurate in-house 3D dosimetry. The optimal formulation and procedure was then applied for the verification of an intensity modulated radiation therapy (IMRT) and a volumetric modulated arc therapy (VMAT) treatment technique. PRESAGE ® formulations were studied for their temporal stability post-irradiation, sensitivity, and linearity of dose response. Dosimeters were read out using a high-resolution optical-CT scanner. Small volumes of PRESAGE ® were irradiated to investigate possible differences in sensitivity for large and small volumes (‘volume effect’). The optimal formulation and read-out technique was applied to the verification of two patient treatments: an IMRT plan and a VMAT plan. A gradual decrease in post-irradiation optical-density was observed in all formulations with DEA-1 exhibiting the best temporal stability with less than 4% variation between 2–22 h post-irradiation. A linear dose response at the 4 h time point was observed for all formulations with an R 2 value >0.99. A large volume effect was observed for DEA-1 with sensitivity of the large dosimeter being ∼63% less than the sensitivity of the cuvettes. For the IMRT and VMAT treatments, the 3D gamma passing rates for 3%/3 mm criteria using absolute measured dose were 99.6 and 94.5% for the IMRT and VMAT treatments, respectively. In summary, this work shows that accurate 3D dosimetry is possible with all three PRESAGE ® formulations. The optimal imaging windows post-irradiation were 3–24 h, 2–6 h, and immediately for the DEA-1, DEA-2, and DX formulations, respectively. Because of the large volume effect, small volume cuvettes are not yet a reliable method for calibration of larger dosimeters to absolute dose. Finally, PRESAGE ® is observed to be a useful method of 3D verification when careful

  11. Intensity Modulated Radiotherapy (IMRT in the postoperative treatment of an adenocarcinoma of the endometrium complicated by a pelvic kidney

    Directory of Open Access Journals (Sweden)

    Novaes Paulo ERS

    2006-11-01

    Full Text Available Abstract Background Pelvic Radiotherapy (RT as a postoperative treatment for endometrial cancer improves local regional control. Brachytherapy also improves vaginal control. Both treatments imply significant side effects that a fine RT technique can help avoiding. Intensity Modulated RT (IMRT enables the treatment of the target volume while protecting normal tissue. It therefore reduces the incidence and severity of side effects. Case We report on a 50 year-old patient with a serous-papiliferous adenocarcinoma of the uterus who was submitted to surgical treatment without lymph node sampling followed by Brachytherapy, and Chemotherapy. The patient had a pelvic kidney, and was therefore treated with IMRT. So far, the patient has been free from relapse and with normal kidney function. Conclusion IMRT is a valid technique to prevent the kidney from radiation damage.

  12. Intensity Modulated Radiotherapy (IMRT) in the postoperative treatment of an adenocarcinoma of the endometrium complicated by a pelvic kidney

    International Nuclear Information System (INIS)

    Castilho, Marcus S; Jacinto, Alexandre A; Viani, Gustavo A; Campana, Andre; Carvalho, Juliana; Ferrigno, Robson; Novaes, Paulo ERS; Fogaroli, Ricardo C; Salvajoli, Joao V

    2006-01-01

    Pelvic Radiotherapy (RT) as a postoperative treatment for endometrial cancer improves local regional control. Brachytherapy also improves vaginal control. Both treatments imply significant side effects that a fine RT technique can help avoiding. Intensity Modulated RT (IMRT) enables the treatment of the target volume while protecting normal tissue. It therefore reduces the incidence and severity of side effects. We report on a 50 year-old patient with a serous-papiliferous adenocarcinoma of the uterus who was submitted to surgical treatment without lymph node sampling followed by Brachytherapy, and Chemotherapy. The patient had a pelvic kidney, and was therefore treated with IMRT. So far, the patient has been free from relapse and with normal kidney function. IMRT is a valid technique to prevent the kidney from radiation damage

  13. IMRT treatment planning-A comparative inter-system and inter-centre planning exercise of the ESTRO QUASIMODO group

    International Nuclear Information System (INIS)

    Bohsung, Joerg; Gillis, Sofie; Arrans, Rafael; Bakai, Annemarie; De Wagter, Carlos; Knoeoes, Tommy; Mijnheer, Ben J.; Paiusco, Marta; Perrin, Bruce A.; Welleweerd, Hans; Williams, Peter

    2005-01-01

    Background and purpose: The purpose of this work was a comparison of realistic IMRT plans based on the same CT-image data set and a common predefined set of dose objectives for the planning target volume and the organs at risk. This work was part of the larger European QUASIMODO IMRT verification project. Materials and methods: Eleven IMRT plans were produced by nine different European groups, each applying a representative set of clinically used IMRT treatment planning systems. The plans produced were to be deliverable in a clinically acceptable treatment time with the local technical equipment. All plans were characterized using a set of different quality measures such as dose-volume histograms, number of monitor units and treatment time. Results: Only one plan was able to fulfil all dose objectives strictly; six plans failed some of the objectives but were still considered to be clinically acceptable; four plans were not able to reach the objectives. Additional quality scores such as the number of monitor units and treatment time showed large variations, which mainly depend on the delivery technique. Conclusion: The presented planning study showed that with nearly all presently available IMRT planning and delivery systems comparable dose distributions could be achieved if the planning goals are clearly defined in advance

  14. A leaf sequencing algorithm to enlarge treatment field length in IMRT

    International Nuclear Information System (INIS)

    Xia Ping; Hwang, Andrew B.; Verhey, Lynn J.

    2002-01-01

    With MLC-based IMRT, the maximum usable field size is often smaller than the maximum field size for conventional treatments. This is due to the constraints of the overtravel distances of MLC leaves and/or jaws. Using a new leaf sequencing algorithm, the usable IMRT field length (perpendicular to the MLC motion) can be mostly made equal to the full length of the MLC field without violating the upper jaw overtravel limit. For any given intensity pattern, a criterion was proposed to assess whether an intensity pattern can be delivered without violation of the jaw position constraints. If the criterion is met, the new algorithm will consider the jaw position constraints during the segmentation for the step and shoot delivery method. The strategy employed by the algorithm is to connect the intensity elements outside the jaw overtravel limits with those inside the jaw overtravel limits. Several methods were used to establish these connections during segmentation by modifying a previously published algorithm (areal algorithm), including changing the intensity level, alternating the leaf-sequencing direction, or limiting the segment field size. The algorithm was tested with 1000 random intensity patterns with dimensions of 21x27 cm2, 800 intensity patterns with higher intensity outside the jaw overtravel limit, and three different types of clinical treatment plans that were undeliverable using a segmentation method from a commercial treatment planning system. The new algorithm achieved a success rate of 100% with these test patterns. For the 1000 random patterns, the new algorithm yields a similar average number of segments of 36.9±2.9 in comparison to 36.6±1.3 when using the areal algorithm. For the 800 patterns with higher intensities outside the jaw overtravel limits, the new algorithm results in an increase of 25% in the average number of segments compared to the areal algorithm. However, the areal algorithm fails to create deliverable segments for 90% of these

  15. Foramen magnum meningiomas: surgical treatment in a single public institution in a developing country

    Directory of Open Access Journals (Sweden)

    Benedicto Oscar Colli

    2014-07-01

    Full Text Available Objective: To analyze the clinical outcome of patients with foramen magnum (FM meningiomas. Method: Thirteen patients (11 Feminine / 2 Masculine with FM meningiomas operated on through lateral suboccipital approach were studied. Clinical outcome were analyzed using survival (SC and recurrence-free survival curves (RFSC. Results: All tumors were World Health Organization grade I. Total, subtotal and partial resections were acchieved in 69.2%, 23.1% and 7.7%, respectively, and SC was better for males and RFSC for females. Tumor location, extent of resection and involvement of vertebral artery/lower cranial nerves did not influence SC and RFSC. Recurrence rate was 7.7%. Operative mortality was 0. Main complications were transient (38.5% and permanent (7.7% lower cranial nerve deficits, cerebrospinal fluid fistula (30.8%, and transient and permanent respiratory difficulties in 7.7% each. Conclusions: FM meningiomas can be adequately treated in public hospitals in developing countries if a multidisciplinary team is available for managing postoperative lower cranial nerve deficits.

  16. A non-voxel-based broad-beam (NVBB) framework for IMRT treatment planning.

    Science.gov (United States)

    Lu, Weiguo

    2010-12-07

    We present a novel framework that enables very large scale intensity-modulated radiation therapy (IMRT) planning in limited computation resources with improvements in cost, plan quality and planning throughput. Current IMRT optimization uses a voxel-based beamlet superposition (VBS) framework that requires pre-calculation and storage of a large amount of beamlet data, resulting in large temporal and spatial complexity. We developed a non-voxel-based broad-beam (NVBB) framework for IMRT capable of direct treatment parameter optimization (DTPO). In this framework, both objective function and derivative are evaluated based on the continuous viewpoint, abandoning 'voxel' and 'beamlet' representations. Thus pre-calculation and storage of beamlets are no longer needed. The NVBB framework has linear complexities (O(N(3))) in both space and time. The low memory, full computation and data parallelization nature of the framework render its efficient implementation on the graphic processing unit (GPU). We implemented the NVBB framework and incorporated it with the TomoTherapy treatment planning system (TPS). The new TPS runs on a single workstation with one GPU card (NVBB-GPU). Extensive verification/validation tests were performed in house and via third parties. Benchmarks on dose accuracy, plan quality and throughput were compared with the commercial TomoTherapy TPS that is based on the VBS framework and uses a computer cluster with 14 nodes (VBS-cluster). For all tests, the dose accuracy of these two TPSs is comparable (within 1%). Plan qualities were comparable with no clinically significant difference for most cases except that superior target uniformity was seen in the NVBB-GPU for some cases. However, the planning time using the NVBB-GPU was reduced many folds over the VBS-cluster. In conclusion, we developed a novel NVBB framework for IMRT optimization. The continuous viewpoint and DTPO nature of the algorithm eliminate the need for beamlets and lead to better plan

  17. A non-voxel-based broad-beam (NVBB) framework for IMRT treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Lu Weiguo, E-mail: wlu@tomotherapy.co [TomoTherapy Inc., 1240 Deming Way, Madison, WI 53717 (United States)

    2010-12-07

    We present a novel framework that enables very large scale intensity-modulated radiation therapy (IMRT) planning in limited computation resources with improvements in cost, plan quality and planning throughput. Current IMRT optimization uses a voxel-based beamlet superposition (VBS) framework that requires pre-calculation and storage of a large amount of beamlet data, resulting in large temporal and spatial complexity. We developed a non-voxel-based broad-beam (NVBB) framework for IMRT capable of direct treatment parameter optimization (DTPO). In this framework, both objective function and derivative are evaluated based on the continuous viewpoint, abandoning 'voxel' and 'beamlet' representations. Thus pre-calculation and storage of beamlets are no longer needed. The NVBB framework has linear complexities (O(N{sup 3})) in both space and time. The low memory, full computation and data parallelization nature of the framework render its efficient implementation on the graphic processing unit (GPU). We implemented the NVBB framework and incorporated it with the TomoTherapy treatment planning system (TPS). The new TPS runs on a single workstation with one GPU card (NVBB-GPU). Extensive verification/validation tests were performed in house and via third parties. Benchmarks on dose accuracy, plan quality and throughput were compared with the commercial TomoTherapy TPS that is based on the VBS framework and uses a computer cluster with 14 nodes (VBS-cluster). For all tests, the dose accuracy of these two TPSs is comparable (within 1%). Plan qualities were comparable with no clinically significant difference for most cases except that superior target uniformity was seen in the NVBB-GPU for some cases. However, the planning time using the NVBB-GPU was reduced many folds over the VBS-cluster. In conclusion, we developed a novel NVBB framework for IMRT optimization. The continuous viewpoint and DTPO nature of the algorithm eliminate the need for beamlets

  18. Experience on IMRT treatment for prostate cancer. Planning, dosimetry and quality assurance; Experiencia en el tratamiento de IMRT en cancer de prostata. Planificacion, dosimetria y garantia de calidad

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Barrado, A.; Garcia Vicente, F.; Fernandez Bedoya, V.; Zapatero Laborda, A.; Fernandez, I.; Bermudez Luna, R.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2011-07-01

    In this study a revision concerning the treatment of prostate cancer with intensity-modulated radiation therapy (IMRT) is performed. Planning and verification of treatments involving dose calculations and image positioning are considered. A set of 110 patients is analysed concerning dosimetry and 92 considering image verification. Dose calculation is verified both experimentally and by means of a monitor unit (MU) calculation system. Positioning control of the prostate is achieved using intraprostatic fiducial markers and digitally reconstructed radiographs (DRRs) as well as a home-made software. All patients studied were consistent with the specifications of the treatment protocol regarding dose prescription in planning target volume (PTV), organ at risk (OAR) dose limitations, dosimetric quality assurance and positioning control. The procedure includes a learning curve considering every aspect of the treatment. The MU calculation system itself has been proved as an effective and functional tool for treatment verification. (Author) 12 refs.

  19. SU-F-T-391: Comparative Study of Treatment Planning Between IMRT and IMAT for Malignant Pleural Mesothelioma

    International Nuclear Information System (INIS)

    Duan, J

    2016-01-01

    Purpose: The purpose of this study was to compare the dosimetric differences between intensitymodulated radiation therapy (IMRT) and intensity modulated arc therapy (IMAT) for malignant pleural mesothelioma (MPM) patients with regard to the sparing effect on organs at risk (OARs), plan quality, and delivery efficiency. Methods: Ten MPM patients were recruited in this study. To avoid the inter-operator variability, IMRT and IMAT plans for each patient were performed by one experienced dosimetrist. The treatment planning optimization process was carried out using the Eclipse 13.0 software. For a fair comparison, the planning target volume (PTV) coverage of the two plans was normalized to the same level. The treatment plans were evaluated on the following dosimetric variables: conformity index (CI) and homogeneity index (HI) for PTV, OARs dose, and the delivery efficiency for each plan. Results: All plans satisfied clinical requirements. The IMAT plans gained better CI and HI. The IMRT plans performed better sparing for heart and lung. Less MUs and control points were found in the IMAT plans. IMAT shortened delivery time compared with IMRT. Conclusion: For MPM, IMAT gains better conformity and homogeneity for PTV with IMRT, but increases the irradiation dose for OARs. IMAT shows an advantage in delivery efficiency.

  20. SU-F-T-391: Comparative Study of Treatment Planning Between IMRT and IMAT for Malignant Pleural Mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Duan, J [Shandong Cancer Hospital and Institute, Jinan, Shandong province (China)

    2016-06-15

    Purpose: The purpose of this study was to compare the dosimetric differences between intensitymodulated radiation therapy (IMRT) and intensity modulated arc therapy (IMAT) for malignant pleural mesothelioma (MPM) patients with regard to the sparing effect on organs at risk (OARs), plan quality, and delivery efficiency. Methods: Ten MPM patients were recruited in this study. To avoid the inter-operator variability, IMRT and IMAT plans for each patient were performed by one experienced dosimetrist. The treatment planning optimization process was carried out using the Eclipse 13.0 software. For a fair comparison, the planning target volume (PTV) coverage of the two plans was normalized to the same level. The treatment plans were evaluated on the following dosimetric variables: conformity index (CI) and homogeneity index (HI) for PTV, OARs dose, and the delivery efficiency for each plan. Results: All plans satisfied clinical requirements. The IMAT plans gained better CI and HI. The IMRT plans performed better sparing for heart and lung. Less MUs and control points were found in the IMAT plans. IMAT shortened delivery time compared with IMRT. Conclusion: For MPM, IMAT gains better conformity and homogeneity for PTV with IMRT, but increases the irradiation dose for OARs. IMAT shows an advantage in delivery efficiency.

  1. Evaluation of DVH-based treatment plan verification in addition to gamma passing rates for head and neck IMRT

    International Nuclear Information System (INIS)

    Visser, Ruurd; Wauben, David J.L.; Groot, Martijn de; Steenbakkers, Roel J.H.M.; Bijl, Henk P.; Godart, Jeremy; Veld, Aart A. van’t; Langendijk, Johannes A.; Korevaar, Erik W.

    2014-01-01

    Background and purpose: Treatment plan verification of intensity modulated radiotherapy (IMRT) is generally performed with the gamma index (GI) evaluation method, which is difficult to extrapolate to clinical implications. Incorporating Dose Volume Histogram (DVH) information can compensate for this. The aim of this study was to evaluate DVH-based treatment plan verification in addition to the GI evaluation method for head and neck IMRT. Materials and methods: Dose verifications of 700 subsequent head and neck cancer IMRT treatment plans were categorised according to gamma and DVH-based action levels. Fractionation dependent absolute dose limits were chosen. The results of the gamma- and DVH-based evaluations were compared to the decision of the medical physicist and/or radiation oncologist for plan acceptance. Results: Nearly all treatment plans (99.7%) were accepted for treatment according to the GI evaluation combined with DVH-based verification. Two treatment plans were re-planned according to DVH-based verification, which would have been accepted using the evaluation alone. DVH-based verification increased insight into dose delivery to patient specific structures increasing confidence that the treatment plans were clinically acceptable. Moreover, DVH-based action levels clearly distinguished the role of the medical physicist and radiation oncologist within the Quality Assurance (QA) procedure. Conclusions: DVH-based treatment plan verification complements the GI evaluation method improving head and neck IMRT-QA

  2. Node-positive left-sided breast cancer. Does VMAT improve treatment plan quality with respect to IMRT?

    Energy Technology Data Exchange (ETDEWEB)

    Pasler, M.; Bartelt, S.; Lutterbach, J. [Lake Constance Radiation Oncology Center Singen, Friedrichshafen (Germany); Georg, D. [Medical University Vienna/AKH Wien, Vienna (Austria). Dept. of Radiooncology; Medical University Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology

    2013-05-15

    Purpose: The aim of the present work was to explore plan quality and dosimetric accuracy of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for lymph node-positive left-sided breast cancer. Methods: VMAT and IMRT plans were generated with the Pinnacle{sup 3} V9.0 treatment planning system for 10 lymph node-positive left-sided breast cancer patients. VMAT plans were created using a single arc and IMRT was performed with 4 beams using 6, 10, and 15 MV photon energy, respectively. Plans were evaluated both manually and automatically using ArtiView trademark. Dosimetric plan verification was performed with a 2D ionization chamber array placed in a full scatter phantom. Results: Photon energy had no significant influence on plan quality for both VMAT and IMRT. Large variability in low doses to the heart was found due to patient anatomy (range V{sub 5} {sub Gy} 26.5-95 %). Slightly more normal tissue dose was found for VMAT (e.g., V{sub Tissue30%} = 22 %) than in IMRT (V{sub Tissue30%} = 18 %). The manual and ArtiView trademark plan evaluation coincided very accurately for most dose metrics (difference < 1 %). In VMAT, 96.7 % of detector points passed the 3 %/3 mm gamma criterion; marginally better accuracy was found in IMRT (98.3 %). Conclusion: VMAT for node-positive left-sided breast cancer retains target homogeneity and coverage when compared to IMRT and allows maximum doses to organs at risk to be reduced. ArtiView trademark enables fast and accurate plan evaluation. (orig.)

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  4. Evaluation of treatment plan quality of IMRT and VMAT with and without flattening filter using Pareto optimal fronts.

    Science.gov (United States)

    Lechner, Wolfgang; Kragl, Gabriele; Georg, Dietmar

    2013-12-01

    To investigate the differences in treatment plan quality of IMRT and VMAT with and without flattening filter using Pareto optimal fronts, for two treatment sites of different anatomic complexity. Pareto optimal fronts (POFs) were generated for six prostate and head-and-neck cancer patients by stepwise reduction of the constraint (during the optimization process) of the primary organ-at-risk (OAR). 9-static field IMRT and 360°-single-arc VMAT plans with flattening filter (FF) and without flattening filter (FFF) were compared. The volume receiving 5 Gy or more (V5 Gy) was used to estimate the low dose exposure. Furthermore, the number of monitor units (MUs) and measurements of the delivery time (T) were used to assess the efficiency of the treatment plans. A significant increase in MUs was found when using FFF-beams while the treatment plan quality was at least equivalent to the FF-beams. T was decreased by 18% for prostate for IMRT with FFF-beams and by 4% for head-and-neck cases, but increased by 22% and 16% for VMAT. A reduction of up to 5% of V5 Gy was found for IMRT prostate cases with FFF-beams. The evaluation of the POFs showed an at least comparable treatment plan quality of FFF-beams compared to FF-beams for both treatment sites and modalities. For smaller targets the advantageous characteristics of FFF-beams could be better exploited. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Effect of photon-beam energy on VMAT and IMRT treatment plan quality and dosimetric accuracy for advanced prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pasler, Marlies; Wirtz, Holger; Lutterbach, Johannes [Lake Constance Radiation Oncology Center Singen-Friedrichshafen, Singen (Germany); Georg, Dietmar [Medical Univ. Vienna (Austria). Dept. of Radiotherapy

    2011-12-15

    The goal of the research was to evaluate treatment plan quality and dosimetric accuracy of volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) plans using 6, 10, and 15 MV photon beams for prostate cancer including lymph nodes. In this retrospective study, VMAT and IMRT plans were generated with the Pinnacle {sup copyright} treatment planning system (TPS) (V9.0) for 10 prostate cancer cases. Each plan consisted of two target volumes: PTV{sub B} included the prostate bed, PTV{sub PC+LN} contained PTV{sub B} and lymph nodes. For plan evaluation statistics, the homogeneity index, conformity index, mean doses, and near-max doses to organs at risk (OAR) were analyzed. Treatment time and number of monitor units were assessed to compare delivery efficiency. Dosimetric plan verification was performed with a 2D ionization chamber array placed in a full scatter phantom. Results: No differences were found for target and OAR parameters in low and high energy photon beam plans for both VMAT and IMRT. A slightly higher low dose volume was detected for 6 MV VMAT plans (normal tissue: D{sub mean} = 16.47 Gy) compared to 10 and 15 MV VMAT plans (D{sub mean} = 15.90 Gy and 15.74 Gy, respectively), similar to the findings in IMRT. In VMAT, > 96% of detector points passed the 3%/ 3 mm {gamma} criterion; marginally better accuracy was found in IMRT (> 97%). Conclusion: For static and rotational IMRT, 15 MV photons did not show advantages over 6 and 10 MV high energy photon beams in large volume pelvic plans. For the investigated TPS and linac combination, 10 MV photon beams can be used as the general purpose energy for intensity modulation.

  6. Single-Arc IMRT?

    International Nuclear Information System (INIS)

    Bortfeld, Thomas; Webb, Steve

    2009-01-01

    The idea of delivering intensity-modulated radiation therapy (IMRT) with a multileaf collimator in a continuous dynamic mode during a single rotation of the gantry has recently gained momentum both in research and industry. In this note we investigate the potential of this Single-Arc IMRT technique at a conceptual level. We consider the original theoretical example case from Brahme et al that got the field of IMRT started. Using analytical methods, we derive deliverable intensity 'landscapes' for Single-Arc as well as standard IMRT and Tomotherapy. We find that Tomotherapy provides the greatest flexibility in shaping intensity landscapes and that it allows one to deliver IMRT in a way that comes close to the ideal case in the transverse plane. Single-Arc and standard IMRT make compromises in different areas. Only in relatively simple cases that do not require substantial intensity modulation will Single-Arc be dosimetrically comparable to Tomotherapy. Compared with standard IMRT, Single-Arc could be dosimetrically superior in certain cases if one is willing to accept the spreading of low dose values over large volumes of normal tissue. In terms of treatment planning, Single-Arc poses a more challenging optimization problem than Tomotherapy or standard IMRT. We conclude that Single-Arc holds potential as an efficient IMRT technique especially for relatively simple cases. In very complex cases, Single-Arc may unduly compromise the quality of the dose distribution, if one tries to keep the treatment time below 2 min or so. As with all IMRT techniques, it is important to explore the tradeoff between plan quality and the efficiency of its delivery carefully for each individual case. (note)

  7. Clinical implications of the anisotropic analytical algorithm for IMRT treatment planning and verification

    International Nuclear Information System (INIS)

    Bragg, Christopher M.; Wingate, Katrina; Conway, John

    2008-01-01

    Purpose: To determine the implications of the use of the Anisotropic Analytical Algorithm (AAA) for the production and dosimetric verification of IMRT plans for treatments of the prostate, parotid, nasopharynx and lung. Methods: 72 IMRT treatment plans produced using the Pencil Beam Convolution (PBC) algorithm were recalculated using the AAA and the dose distributions compared. Twenty-four of the plans were delivered to inhomogeneous phantoms and verification measurements made using a pinpoint ionisation chamber. The agreement between the AAA and measurement was determined. Results: Small differences were seen in the prostate plans, with the AAA predicting slightly lower minimum PTV doses. In the parotid plans, there were small increases in the lens and contralateral parotid doses while the nasopharyngeal plans revealed a reduction in the volume of the PTV covered by the 95% isodose (the V 95% ) when the AAA was used. Large changes were seen in the lung plans, the AAA predicting reductions in the minimum PTV dose and large reductions in the V 95% . The AAA also predicted small increases in the mean dose to the normal lung and the V 20 . In the verification measurements, all AAA calculations were within 3% or 3.5 mm distance to agreement of the measured doses. Conclusions: The AAA should be used in preference to the PBC algorithm for treatments involving low density tissue but this may necessitate re-evaluation of plan acceptability criteria. Improvements to the Multi-Resolution Dose Calculation algorithm used in the inverse planning are required to reduce the convergence error in the presence of lung tissue. There was excellent agreement between the AAA and verification measurements for all sites

  8. Intensity modulated radiotherapy (IMRT) with concurrent chemotherapy as definitive treatment of locally advanced esophageal cancer

    International Nuclear Information System (INIS)

    Roeder, Falk; Nicolay, Nils H; Nguyen, Tam; Saleh-Ebrahimi, Ladan; Askoxylakis, Vasilis; Bostel, Tilman; Zwicker, Felix; Debus, Juergen; Timke, Carmen; Huber, Peter E

    2014-01-01

    To report our experience with increased dose intensity-modulated radiation and concurrent systemic chemotherapy as definitive treatment of locally advanced esophageal cancer. We analyzed 27 consecutive patients with histologically proven esophageal cancer, who were treated with increased-dose IMRT as part of their definitive therapy. The majority of patients had T3/4 and/or N1 disease (93%). Squamous cell carcinoma was the dominating histology (81%). IMRT was delivered in step-and-shoot technique in all patients using an integrated boost concept. The boost volume was covered with total doses of 56-60 Gy (single dose 2-2.14 Gy), while regional nodal regions received 50.4 Gy (single dose 1.8 Gy) in 28 fractions. Concurrent systemic therapy was scheduled in all patients and administered in 26 (96%). 17 patients received additional adjuvant systemic therapy. Loco-regional control, progression-free and overall survival as well as acute and late toxicities were retrospectively analyzed. In addition, quality of life was prospectively assessed according to the EORTC QLQs (QLQ-OG25, QLQ-H&N35 and QLQ-C30). Radiotherapy was completed as planned in all but one patient (96%), and 21 patients received more than 80% of the planned concurrent systemic therapy. We observed ten locoregional failures, transferring into actuarial 1-, 2- and 3-year-locoregional control rates of 77%, 65% and 48%. Seven patients developed distant metastases, mainly to the lung (71%). The actuarial 1-, 2- and 3-year-disease free survival rates were 58%, 48% and 36%, and overall survival rates were 82%, 61% and 56%. The concept was well tolerated, both in the clinical objective examination and also according to the subjective answers to the QLQ questionnaire. 14 patients (52%) suffered from at least one acute CTC grade 3/4 toxicity, mostly hematological side effects or dysphagia. Severe late toxicities were reported in 6 patients (22%), mostly esophageal strictures and ulcerations. Severe side effects to

  9. Gamma knife radiosurgery in the treatment of a meningioma in a patient on maintenance hemodialysis: A case report

    International Nuclear Information System (INIS)

    Matsuo, H.; Nakamura, K.; Hayashi, J.; Nakura, T.; Saruki, K.; Andoh, Y.; Shibazaki, T.; Kubo, K.

    1994-01-01

    To our knowledge, this is the first report ever on the implementation and results of gamma knife radiosurgery in a regularly dialysed patient. The case presented is that of a 59 year-old female patient with a meningioma. Her initial clinical presentation was with sustained headache. Diagnosis was made by using a brain CT scan and MR imaging. Treatment was performed literally without opening the skull. There was only one complication, namely that of postirradiation brain edema, which developed 19 weeks after the operation, and responded dramatically to steroid administration. This is one of the rare side effects of gamma knife therapy, but does not seem to be related to the fact that the patient was uremic. Gamma knife therapy was successful in this patient and her safety was no more compromised than that of a nonuremic patient undergoing radiosurgery. (authors)

  10. Evaluation of IMRT plans of prostate carcinoma from four treatment planning systems based on Monte Carlo

    International Nuclear Information System (INIS)

    Chi Zifeng; Han Chun; Liu Dan; Cao Yankun; Li Runxiao

    2011-01-01

    Objective: With the Monte Carlo method to recalculate the IMRT dose distributions from four TPS to provide a platform for independent comparison and evaluation of the plan quality.These results will help make a clinical decision as which TPS will be used for prostate IMRT planning. Methods: Eleven prostate cancer cases were planned with the Corvus, Xio, Pinnacle and Eclipse TPS. The plans were recalculated by Monte Carlo using leaf sequences and MUs for individual plans. Dose-volume-histograms and isodose distributions were compared. Other quantities such as D min (the minimum dose received by 99% of CTV/PTV), D max (the maximum dose received by 1% of CTV/PTV), V 110% , V 105% , V 95% (the volume of CTV/PTV receiving 110%, 105%, 95% of the prescription dose), the volume of rectum and bladder receiving >65 Gy and >40 Gy, and the volume of femur receiving >50 Gy were evaluated. Total segments and MUs were also compared. Results: The Monte Carlo results agreed with the dose distributions from the TPS to within 3%/3 mm. The Xio, Pinnacle and Eclipse plans show less target dose heterogeneity and lower V 65 and V 40 for the rectum and bladder compared to the Corvus plans. The PTV D min is about 2 Gy lower for Xio plans than others while the Corvus plans have slightly lower female head V 50 (0.03% and 0.58%) than others. The Corvus plans require significantly most segments (187.8) and MUs (1264.7) to deliver and the Pinnacle plans require fewest segments (82.4) and MUs (703.6). Conclusions: We have tested an independent Monte Carlo dose calculation system for dose reconstruction and plan evaluation. This system provides a platform for the fair comparison and evaluation of treatment plans to facilitate clinical decision making in selecting a TPS and beam delivery system for particular treatment sites. (authors)

  11. PET/CT Staging Followed by Intensity-Modulated Radiotherapy (IMRT) Improves Treatment Outcome of Locally Advanced Pharyngeal Carcinoma: a matched-pair comparison

    International Nuclear Information System (INIS)

    Rothschild, Sacha; Studer, Gabriela; Seifert, Burkhardt; Huguenin, Pia; Glanzmann, Christoph; Davis, J Bernard; Lütolf, Urs M; Hany, Thomas F; Ciernik, I Frank

    2007-01-01

    Impact of non-pharmacological innovations on cancer cure rates is difficult to assess. It remains unclear, whether outcome improves with 2- [18-F]-fluoro-2-deoxyglucose-positron emission tomography and integrated computer tomography (PET/CT) and intensity-modulated radiotherapy (IMRT) for curative treatment of advanced pharyngeal carcinoma. Forty five patients with stage IVA oro- or hypopharyngeal carcinoma were staged with an integrated PET/CT and treated with definitive chemoradiation with IMRT from 2002 until 2005. To estimate the impact of PET/CT with IMRT on outcome, a case-control analysis on all patients with PET/CT and IMRT was done after matching with eighty six patients treated between 1991 and 2001 without PET/CT and 3D-conformal radiotherapy with respect to gender, age, stage, grade, and tumor location with a ratio of 1:2. Median follow-up was eighteen months (range, 6–49 months) for the PET/CT-IMRT group and twenty eight months (range, 1–168 months) for the controls. PET/CT and treatment with IMRT improved cure rates compared to patients without PET/CT and IMRT. Overall survival of patients with PET/CT and IMRT was 97% and 91% at 1 and 2 years respectively, compared to 74% and 54% for patients without PET/CT or IMRT (p = 0.002). The event-free survival rate of PET/CT-IMRT group was 90% and 80% at 1 and 2 years respectively, compared to 72% and 56% in the control group (p = 0.005). PET/CT in combination with IMRT and chemotherapy for pharyngeal carcinoma improve oncological therapy of pharyngeal carcinomas. Long-term follow-up is needed to confirm these findings

  12. Intensity Modulated Radiotherapy (IMRT) in the postoperative treatment of an adenocarcinoma of the endometrium complicated by a pelvic kidney

    OpenAIRE

    Castilho, Marcus S; Jacinto, Alexandre A; Viani, Gustavo A; Campana, Andre; Carvalho, Juliana; Ferrigno, Robson; Novaes, Paulo ERS; Fogaroli, Ricardo C; Salvajoli, Joao V

    2006-01-01

    Abstract Background Pelvic Radiotherapy (RT) as a postoperative treatment for endometrial cancer improves local regional control. Brachytherapy also improves vaginal control. Both treatments imply significant side effects that a fine RT technique can help avoiding. Intensity Modulated RT (IMRT) enables the treatment of the target volume while protecting normal tissue. It therefore reduces the incidence and severity of side effects. Case We report on a 50 year-old patient with a serous-papilif...

  13. Multiple meningiomas CASE SERIES

    African Journals Online (AJOL)

    masses in the right parietal and parasagittal region (Figs 1a and b). Case 2: A ... scan showed hyperdense parasagittal and left cerebellopontine angle meningiomas (Figs ... Meningiomas are the most common primary non-glial brain tumours.

  14. Meningioma of the scapula

    Energy Technology Data Exchange (ETDEWEB)

    Llauger, Jaume; Aixut, Sonia; Canete, Noemi; Palmer, Jaume; Sola, Marta [Universitat Autonoma de Barcelona, Department of Radiology, Hospital de la Santa Creu I Sant Pau, Barcelona (Spain); Bague, Silvia [Universitat Autonoma de Barcelona, Department of Pathology, Hospital de la Santa Creu I Sant Pau, Barcelona (Spain)

    2008-02-15

    Meningiomas account for approximately 15% of all intracranial tumors and are the most common non-glial primary tumors of the central nervous system. Most meningiomas are benign neoplasms with characteristic imaging features. Primary extradural meningiomas account for only 1-2% of all meningiomas. They must be differentiated from intradural meningiomas with secondary extradural extension and/or metastases. The vast majority of extradural meningiomas are found in the skull or in the head and neck region. We report on an extremely rare case of primary extradural meningioma that was located in the scapula. The lesion was resected. Radiographic findings and pathologic features are discussed. To the best of our knowledge, this form of presentation of an extradural meningioma has not been previously described. (orig.)

  15. Predicting objective function weights from patient anatomy in prostate IMRT treatment planning

    International Nuclear Information System (INIS)

    Lee, Taewoo; Hammad, Muhannad; Chan, Timothy C. Y.; Craig, Tim; Sharpe, Michael B.

    2013-01-01

    Purpose: Intensity-modulated radiation therapy (IMRT) treatment planning typically combines multiple criteria into a single objective function by taking a weighted sum. The authors propose a statistical model that predicts objective function weights from patient anatomy for prostate IMRT treatment planning. This study provides a proof of concept for geometry-driven weight determination. Methods: A previously developed inverse optimization method (IOM) was used to generate optimal objective function weights for 24 patients using their historical treatment plans (i.e., dose distributions). These IOM weights were around 1% for each of the femoral heads, while bladder and rectum weights varied greatly between patients. A regression model was developed to predict a patient's rectum weight using the ratio of the overlap volume of the rectum and bladder with the planning target volume at a 1 cm expansion as the independent variable. The femoral head weights were fixed to 1% each and the bladder weight was calculated as one minus the rectum and femoral head weights. The model was validated using leave-one-out cross validation. Objective values and dose distributions generated through inverse planning using the predicted weights were compared to those generated using the original IOM weights, as well as an average of the IOM weights across all patients. Results: The IOM weight vectors were on average six times closer to the predicted weight vectors than to the average weight vector, usingl 2 distance. Likewise, the bladder and rectum objective values achieved by the predicted weights were more similar to the objective values achieved by the IOM weights. The difference in objective value performance between the predicted and average weights was statistically significant according to a one-sided sign test. For all patients, the difference in rectum V54.3 Gy, rectum V70.0 Gy, bladder V54.3 Gy, and bladder V70.0 Gy values between the dose distributions generated by the

  16. Comparison of online IGRT techniques for prostate IMRT treatment: Adaptive vs repositioning correction

    International Nuclear Information System (INIS)

    Thongphiew, Danthai; Wu, Q. Jackie; Lee, W. Robert; Chankong, Vira; Yoo, Sua; McMahon, Ryan; Yin Fangfang

    2009-01-01

    This study compares three online image guidance techniques (IGRT) for prostate IMRT treatment: bony-anatomy matching, soft-tissue matching, and online replanning. Six prostate IMRT patients were studied. Five daily CBCT scans from the first week were acquired for each patient to provide representative ''snapshots'' of anatomical variations during the course of treatment. Initial IMRT plans were designed for each patient with seven coplanar 15 MV beams on a Eclipse treatment planning system. Two plans were created, one with a PTV margin of 10 mm and another with a 5 mm PTV margin. Based on these plans, the delivered dose distributions to each CBCT anatomy was evaluated to compare bony-anatomy matching, soft-tissue matching, and online replanning. Matching based on bony anatomy was evaluated using the 10 mm PTV margin (''bone10''). Soft-tissue matching was evaluated using both the 10 mm (''soft10'') and 5 mm (''soft5'') PTV margins. Online reoptimization was evaluated using the 5 mm PTV margin (''adapt''). The replanning process utilized the original dose distribution as the basis and linear goal programming techniques for reoptimization. The reoptimized plans were finished in less than 2 min for all cases. Using each IGRT technique, the delivered dose distribution was evaluated on all 30 CBCT scans (6 patientsx5CBCT/patient). The mean minimum dose (in percentage of prescription dose) to the CTV over five treatment fractions were in the ranges of 99%-100%(SD=0.1%-0.8%), 65%-98%(SD=0.4%-19.5%), 87%-99%(SD=0.7%-23.3%), and 95%-99%(SD=0.4%-10.4%) for the adapt, bone10, soft5, and soft10 techniques, respectively. Compared to patient position correction techniques, the online reoptimization technique also showed improvement in OAR sparing when organ motion/deformations were large. For bladder, the adapt technique had the best (minimum) D90, D50, and D30 values for 24, 17, and 15 fractions out of 30 total fractions, while it also had the best D90, D50, and D30 values for

  17. Prostate IMRT fractionation strategies. Two-phase treatment versus simultaneous integrated boost

    International Nuclear Information System (INIS)

    Stavrev, P.; Hristov, D.

    2003-01-01

    Background. The purpose of the study was to investigate the radiobiological effect of the number of fractions, position uncertainties and clonogen spread (microscopic disease) on two different inverse treatment planning alternatives: (a) 2-phase strategy; (b) simultaneous integrated boost (SIB). Material and methods. The tumour control probability (TCP) and normal tissue complication probability (NTCP) were calculated for the 2-phase strategy, which has well defined fractionation scheme and compared to the TCP and NTCP for the SIB strategy calculated as a function of the number of fractions. For a 7-beam IMRT prostate treatment, we have performed inverse treatment planning for the two different strategies following the above method. Results. When the position uncertainties and clonogen spread were accounted for in the TCP calculation a drop as large as 10% was found. A drop of 5-7% in the TCP was obtained for the SIB strategy, if delivered in the same number of fractions as the 2-phased one. Conclusions. The potential of inverse planning to design tight conformal dose distributions is fully revealed in the SIB optimization process. The optimized SIB superior dose distributions require modification of the delivered dose per fraction and therefore careful selection of the fractionation regime. Hence physically optimized SIB treatments may not always lead to better tumour control and tissue sparing. (author)

  18. Comparison of IMRT Treatment Plans Between Linac and Helical Tomotherapy Based on Integral Dose and Inhomogeneity Index

    International Nuclear Information System (INIS)

    Shi Chengyu; Penagaricano, Jose; Papanikolaou, Niko

    2008-01-01

    Intensity modulated radiotherapy (IMRT) is an advanced treatment technology for radiation therapy. There are several treatment planning systems (TPS) that can generate IMRT plans. These plans may show different inhomogeneity indices to the planning target volume (PTV) and integral dose to organs at risk (OAR). In this study, we compared clinical cases covering different anatomical treatment sites, including head and neck, brain, lung, prostate, pelvis, and cranio-spinal axis. Two treatment plans were developed for each case using Pinnacle 3 and helical tomotherapy (HT) TPS. The inhomogeneity index of the PTV and the non-tumor integral dose (NTID) were calculated and compared for each case. Despite the difference in the number of effective beams, in several cases, NTID did not increase from HT as compared to the step-and-shoot delivery method. Six helical tomotherapy treatment plans for different treatment sites have been analyzed and compared against corresponding step-and-shoot plans generated with the Pinnacle 3 planning system. Results show that HT may produce plans with smaller integral doses to healthy organs, and fairly homogeneous doses to the target as compared to linac-based step-and-shoot IMRT planning in special treatment site such as cranio-spinal

  19. Assessment of new radiation oncology technology and treatments in radiation oncology the ANROTAT project and collection of IMRT specific data

    International Nuclear Information System (INIS)

    Haworth, A.; Corry, J.; Kron, T.; Duchesne, G.; Ng, M.; Burmeister, B.

    2010-01-01

    Full text: Medical physicists (MP) are familiar with assessing new radiation oncology technology and treatments ( ROT A T) for their own departments but are not usually involved in providing advice to government for funding these technologies. This paper describes the role of the MP within the Commonwealth Government Department of Health and Aging initiative to develop a generic framework for assessment of ROTAT and the collection of data to support Med care Benefits Scheme (MBS) funding of IMRT. The clinical trials group TROG is developing a generic framework for the assessment of NROTAT. This will be tested and data collected to support applications for MBS funding of IMRT and IGRT. The tumour sites of nasopharynx, post-prostatectomy and anal canal have been selected to represent sites that are commonly, occasionally and rarely treated with IMRT respectively. Site selection for data collection will represent a broad range of clinical practices. Data quality is assured through TROG QA procedures and will include dosimetry audits. The final report will assess the clinical efficacy, cost effectiveness and safety of IMRT compared to 3DCRT. Existing clinical trial protocols form the basis for data collection and surrogate endpoints are being developed. Key publications have been identified that correlate specific dose-volume histogram parameters with clinical end-points, recognising limitations of these data in the 1MRT setting. Engagement of MPs within this project will help ensure collection of high quality data that ultimately aims to secure appropriate funding to ensure our patients receive best clinical care. (author)

  20. Poster — Thur Eve — 33: The Influence of a Modeled Treatment Couch on Dose Distributions During IMRT and RapidArc Treatment Delivery

    International Nuclear Information System (INIS)

    Aldosary, Ghada; Nobah, Ahmad; Al-Zorkani, Faisal; Moftah, Belal; Devic, Slobodan

    2014-01-01

    Treatment couches have been known to perturb dose delivery in patients. This effect is most pronounced in techniques such as IMRT and RapidArc. Although modern treatment planning systems (TPS) include data for a “default” treatment couch, actual couches are not manufactured identically. Thus, variations in their Hounsfield Unit (HU) values may exist. This study demonstrates a practical and simple method of acquiring reliable HU data for any treatment couch. We also investigate the effects of both the default and modeled treatment couches on absorbed dose. Experimental verifications show that by neglecting to incorporate the treatment couch in the TPS, dose differences of up to 9.5% and 7.3% were present for 4 MV and 10 MV photon beams, respectively. Furthermore, a clinical study based on a cohort of 20 RapidArc and IMRT (brain, pelvis and abdominal) cases is performed. 2D dose distributions show that without the couch in the planning phase, differences ≤ 4.6% and 5.9% for RapidArc and IMRT cases are present for the same cases that the default couch was added to. Additionally, in comparison to the default couch, employing the modeled couch in the calculation process influences dose distributions by ≤ 2.7% and 8% for RapidArc and IMRT cases, respectively. This result was found to be site specific; where an accurate couch proves to be preferable for IMRT brain plans. As such, adding the couch during dose calculation decreases dose calculation errors, and a precisely modeled treatment couch offers higher dose delivery accuracy for brain treatment using IMRT

  1. Poster — Thur Eve — 33: The Influence of a Modeled Treatment Couch on Dose Distributions During IMRT and RapidArc Treatment Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Aldosary, Ghada [Medical Physics Unit, Montreal General Hospital, McGill University, Montreal, Quebec (Canada); Nobah, Ahmad; Al-Zorkani, Faisal; Moftah, Belal [Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Devic, Slobodan [Department of Radiation Oncology, Jewish General Hospital, McGill University, Montreal, Quebec (Canada)

    2014-08-15

    Treatment couches have been known to perturb dose delivery in patients. This effect is most pronounced in techniques such as IMRT and RapidArc. Although modern treatment planning systems (TPS) include data for a “default” treatment couch, actual couches are not manufactured identically. Thus, variations in their Hounsfield Unit (HU) values may exist. This study demonstrates a practical and simple method of acquiring reliable HU data for any treatment couch. We also investigate the effects of both the default and modeled treatment couches on absorbed dose. Experimental verifications show that by neglecting to incorporate the treatment couch in the TPS, dose differences of up to 9.5% and 7.3% were present for 4 MV and 10 MV photon beams, respectively. Furthermore, a clinical study based on a cohort of 20 RapidArc and IMRT (brain, pelvis and abdominal) cases is performed. 2D dose distributions show that without the couch in the planning phase, differences ≤ 4.6% and 5.9% for RapidArc and IMRT cases are present for the same cases that the default couch was added to. Additionally, in comparison to the default couch, employing the modeled couch in the calculation process influences dose distributions by ≤ 2.7% and 8% for RapidArc and IMRT cases, respectively. This result was found to be site specific; where an accurate couch proves to be preferable for IMRT brain plans. As such, adding the couch during dose calculation decreases dose calculation errors, and a precisely modeled treatment couch offers higher dose delivery accuracy for brain treatment using IMRT.

  2. Cystic meningiomas in 2 dogs

    International Nuclear Information System (INIS)

    Bagley, R.S.; Kornegay, J.N.; Lane, S.B.; Thrall, D.L.; Page, R.L.

    1996-01-01

    Two dogs with signs of forebrain disease had hypodense lesions on computed tomography evaluation. Magnetic resonance imaging of the first dog showed a hypointense lesion on the T1-weighted scan and a hyperintense lesion on T2-weighted scanning. At surgery, both dogs had a primary cystic intracranial lesion, and the abnormal tissue adjacent to the cyst had histological features of meningioma. Each dog underwent whole brain irradiation after surgery, and 1 dog lived for 3 years after treatment. While uncommon, meningioma should be considered as a differential diagnosis in dogs with cystic intracranial lesions

  3. Automated selection of beam orientations and segmented intensity-modulated radiotherapy (IMRT) for treatment of oesophagus tumors

    International Nuclear Information System (INIS)

    Woudstra, Evert; Heijmen, Ben J.M.; Storchi, Pascal R.M.

    2005-01-01

    Background and purpose: For some treatment sites, there is evidence in the literature that five to nine equiangular input beam directions are enough for generating IMRT plans. For oesophagus cancer, there is a report showing that going from four to nine beams may even result in lower quality plans. In this paper, our previously published algorithm for automated beam angle selection (Cycle) has been extended to include segmented IMRT. For oesophagus cancer patients, we have investigated whether automated orientation selection from a large number of equiangular input beam directions (up to thirty-six) for IMRT optimisation can result in improved lung sparing. Materials and methods: CT-data from five oesophagus patients treated recently in our institute were used for this study. For a prescribed mean PTV dose of 55 Gy, Cycle was used in an iterative procedure to minimise the mean lung dose under the following hard constraints: standard deviation for PTV dose inhomogeneity 2% (1,1 Gy), maximum spinal cord dose 45 Gy. Conformal radiotherapy (CFRT) and IMRT plans for a standard four field oesophagus beam configuration were compared with IMRT plans generated by automated selection from nine or thirty-six equiangular input beam orientations. Comparisons were also made with dose distributions generated with our commercial treatment planning system (TPS), and with observations in the literature. Results: Using Cycle, automated orientation selection from nine or thirty-six input beam directions resulted in improved lung sparing compared to the four field set-ups. Compared to selection from nine input orientations, selection from thirty-six directions did always result in lower mean lung doses, sometimes with even fewer non-zero weight beams. On average only seven beams with a non-zero weight were enough for obtaining the lowest mean lung dose, yielding clinically feasible plans even in case of thirty-six input directions for the optimisation process. With our commercial TPS

  4. Comparison of whole-field simultaneous integrated boost VMAT and IMRT in the treatment of nasopharyngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xiance; Yi, Jinling; Zhou, Yongqiang; Yan, Huawei; Han, Ce; Xie, Congying, E-mail: billy07@wzhospital.cn

    2013-01-01

    To study the feasibility of using volumetric-modulated arc therapy (VMAT) to deliver whole-field simultaneous integrated boost (WF-SIB) to treat patients with nasopharyngeal cancer (NPC). WF-SIB intensity-modulated radiotherapy (IMRT) plans, one-arc WF-SIB VMAT plans, and two-arc WF-SIB VMAT plans were generated with identical objective functions for 8 patients with NPC of various stages. Isodose distributions and dose-volume histograms were evaluated. Dosimetric and biological quality indices of clinical target volume (CTV) and organs at risk (OARs) were calculated to study the optimization capability of these 3 modalities in the treatment of patients with NPC. The optimization time, delivery time, required monitor units (MUs), and delivery accuracy were also compared to investigate the feasibility of these 3 modalities. There was no significant difference (p = 0.92) in target coverage (TC) between WF-SIB IMRT (99.00 ± 0.79) and two-arc WF-SIB VMAT (97.98 ± 1.29). However, both had higher TC than one-arc VMAT plans (89.92 ± 6.32, p < 0.01). IMRT demonstrated the best protection of the spinal cord, whereas two-arc VMAT showed the minimum D{sub max} to OARs. No other significant differences were observed among these 3 modalities on CTV coverage and OAR sparing. The delivery and MU efficiency of one-arc and two-arc WF-SIB VMAT were greatly improved compared with WF-SIB IMRT. The optimization time of one-arc and two-arc WF-SIB VMAT plans were 5 and 10 times greater than that of WF-SIB IMRT, respectively. The delivery accuracy of WF-SIB VMAT was not affected by the increased freedom. For patients with NPC, one-arc WF-SIB VMAT might not be able to achieve sufficient TC, whereas two-arc WF-SIB VMAT was able to achieve reasonable TC. No significant advantage on OAR protection was demonstrated by VMAT compared with IMRT. WF-SIB VMAT has significantly shorter delivery times, but WF-SIB IMRT may still be the first treatment choice for patients with NPC.

  5. A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

    OpenAIRE

    Daniel L Saenz; Bhudatt R Paliwal; John E Bayouth

    2014-01-01

    ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This ...

  6. Implementation of dosimetric quality control on IMRT and VMAT treatments in radiotherapy using diodes; Implementacion de control de calidad dosimetrico en tratamientos de IMRT y VMAT en radioterapia usando diodos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, A.; Garcia, B.; Ramirez, J.; Marquina, J., E-mail: andres.gonzales@aliada.com.pe [ALIADA, Oncologia Integral, Av. Jose Galvez Barrenechea 1044, San Isidro, Lima 27 (Peru)

    2014-08-15

    To implement quality control of IMRT and VMAT treatments Rapid Arc radiotherapy using diode array. Were tested 90 patients with IMRT and VMAT Rapid Arc, comparing the planned dose to the dose administered, used the Map-Check-2 and Arc-Check of Sun Nuclear, they using the gamma factor for calculating and using comparison parameters 3% / 3m m. The statistic shows that the quality controls of the 90 patients analyzed, presented a percentage of diodes that pass the test between 96,7% and 100,0% of the irradiated diodes. Implemented in Clinical ALIADA Oncologia Integral, the method for quality control of IMRT and VMAT treatments Rapid Arc radiotherapy using diode array. (Author)

  7. Patient geometry-driven information retrieval for IMRT treatment plan quality control

    International Nuclear Information System (INIS)

    Wu Binbin; Ricchetti, Francesco; Sanguineti, Giuseppe; Kazhdan, Misha; Simari, Patricio; Chuang Ming; Taylor, Russell; Jacques, Robert; McNutt, Todd

    2009-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) treatment plan quality depends on the planner's level of experience and the amount of time the planner invests in developing the plan. Planners often unwittingly accept plans when further sparing of the organs at risk (OARs) is possible. The authors propose a method of IMRT treatment plan quality control that helps planners to evaluate the doses of the OARs upon completion of a new plan. Methods: It is achieved by comparing the geometric configurations of the OARs and targets of a new patient with those of prior patients, whose plans are maintained in a database. They introduce the concept of a shape relationship descriptor and, specifically, the overlap volume histogram (OVH) to describe the spatial configuration of an OAR with respect to a target. The OVH provides a way to infer the likely DVHs of the OARs by comparing the relative spatial configurations between patients. A database of prior patients is built to serve as an external reference. At the conclusion of a new plan, planners search through the database and identify related patients by comparing the OAR-target geometric relationships of the new patient with those of prior patients. The treatment plans of these related patients are retrieved from the database and guide planners in determining whether lower doses delivered to the OARs in the new plan are feasible. Results: Preliminary evaluation is promising. In this evaluation, they applied the analysis to the parotid DVHs of 32 prior head-and-neck patients, whose plans are maintained in a database. Each parotid was queried against the other 63 parotids to determine whether a lower dose was possible. The 17 parotids that promised the greatest reduction in D 50 (DVH dose at 50% volume) were flagged. These 17 parotids came from 13 patients. The method also indicated that the doses of the other nine parotids of the 13 patients could not be reduced, so they were included in the replanning process as

  8. Orbital meningioma, the Utrecht experience

    NARCIS (Netherlands)

    Mourits, Maarten Ph.; Berkelbach van der Sprenkel, Jan Willem

    2001-01-01

    AIMS. 1) To evaluate epidemiological data (age, gender, initial complaints, and ophthalmic findings) of a patient cohort with a primary or secondary orbital meningioma. 2) To evaluate the clinical course of these patients. 3) To evaluate the outcome of treatment. PATIENTS AND METHODS. All

  9. IMRT: Improvement in treatment planning efficiency using NTCP calculation independent of the dose-volume-histogram

    International Nuclear Information System (INIS)

    Grigorov, Grigor N.; Chow, James C.L.; Grigorov, Lenko; Jiang, Runqing; Barnett, Rob B.

    2006-01-01

    The normal tissue complication probability (NTCP) is a predictor of radiobiological effect for organs at risk (OAR). The calculation of the NTCP is based on the dose-volume-histogram (DVH) which is generated by the treatment planning system after calculation of the 3D dose distribution. Including the NTCP in the objective function for intensity modulated radiation therapy (IMRT) plan optimization would make the planning more effective in reducing the postradiation effects. However, doing so would lengthen the total planning time. The purpose of this work is to establish a method for NTCP determination, independent of a DVH calculation, as a quality assurance check and also as a mean of improving the treatment planning efficiency. In the study, the CTs of ten randomly selected prostate patients were used. IMRT optimization was performed with a PINNACLE3 V 6.2b planning system, using planning target volume (PTV) with margins in the range of 2 to 10 mm. The DVH control points of the PTV and OAR were adapted from the prescriptions of Radiation Therapy Oncology Group protocol P-0126 for an escalated prescribed dose of 82 Gy. This paper presents a new model for the determination of the rectal NTCP ( R NTCP). The method uses a special function, named GVN (from Gy, Volume, NTCP), which describes the R NTCP if 1 cm 3 of the volume of intersection of the PTV and rectum (R int ) is irradiated uniformly by a dose of 1 Gy. The function was 'geometrically' normalized using a prostate-prostate ratio (PPR) of the patients' prostates. A correction of the R NTCP for different prescribed doses, ranging from 70 to 82 Gy, was employed in our model. The argument of the normalized function is the R int , and parameters are the prescribed dose, prostate volume, PTV margin, and PPR. The R NTCPs of another group of patients were calculated by the new method and the resulting difference was <±5% in comparison to the NTCP calculated by the PINNACLE3 software where Kutcher's dose

  10. Radiation therapy technology innovations applied to the treatment of head and neck patients: - Clinical results of Intensity Modulated Radiotherapy (IMRT), - Contribution of Image Guided Radiotherapy (IGRT) in the management of head and neck patients treated with IMRT

    International Nuclear Information System (INIS)

    Graff-Cailleaud, Pierre

    2011-01-01

    Numerous and exciting technological innovations were recently developed in radiotherapy. We aimed to assess benefits in two specific fields. 1) Clinical results of Intensity Modulated Radiotherapy (IMRT) applied to the treatment of Head and Neck (H and N) patients. The first study was a long-term mono-centric prospective registration of all H and N patients treated with IMRT in our institution. Locoregional control was excellent and toxicities limited. Recurrences were in-field. Dosimetric recommendations (parotids mean dose) were established. The second study assessed the impact of IMRT on health-related quality of life for H and N patients through a multicentric matched-pair comparison with conventional radiotherapy. Outstanding benefits were observed particularly in the fields of salivary dysfunction and oral discomfort. 2) Contribution of Image Guided Radiotherapy (IGRT) in the management of H and N patients treated with IMRT. The first study was a monitoring of delivered dose, using 3D dose recalculation from Megavoltage Cone-Beam CT (CBCT), as a quality assurance measure of a panel of H and N IMRT patients aligned with IGRT. Dosimetric consequences of anatomical changes were assessed. Contribution of color-coded MVCBCT dose-difference maps was studied. The aim of the second study was to quantify the inherent relative mobility between anatomic regions of the H and N area and to assess the dosimetric impact of several different matching procedures. Recommendations for the use of CBCT images in a daily practice were established. (author) [fr

  11. Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Ogita, Mikio; Yamashita, Koichi; Kotsuma, Tadayuki; Shiomi, Hiroya; Tsubokura, Takuji; Kodani, Naohiro; Nishimura, Takuya; Aibe, Norihiro; Udono, Hiroki; Nishikata, Manabu; Baba, Yoshimi

    2011-01-01

    To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise. We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan. The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm 3 (range, 7.17 - 14.3 cm 3 ) and 1.99 for pituitary adenoma, and 6.86 cm 3 (range 6.05 - 14.6 cm 3 ) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm 3 for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm 3 (p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm 3 ) than group 2 (6.91 ± 0.7 cm 3 , p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring. Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract

  12. Meningioma anaplásico Anaplastic meningioma

    Directory of Open Access Journals (Sweden)

    Arlines Alina Piña Tornés

    2013-03-01

    Full Text Available Se presenta el caso clínico de un paciente que comenzó a presentar cefalea, vértigos, trastornos visuales y pérdida del equilibrio. Mediante la resonancia magnética se visualizó una imagen tumoral parietal izquierda de 3 cm diámetro, de localización extraaxial y contornos lobulados bien definidos, con gran captación no homogénea de contraste, rodeada de extenso edema perilesional. Se realizó angiotomografía, previa a la cirugía, en busca de irrigación y daño vascular. Se logró la resección de 95% de la lesión (grado II de Simpson, que incluyó duramadre adyacente infiltrada y respetó el seno longitudinal superior. Los resultados anatomopatológicos confirmaron que se trataba de un meningioma anaplásico de grado III, con criterio de tratamiento coadyuvante.The case report of a patient who began presenting headache, vertigos, visual disorders and loss of balance is presented. By means of the magnetic resonance a left tumoral parietal image of 3 cm diameter was visualized, of extra-axial localization and well defined lobulated contours, with great non-homogeneous zones of contrast, surrounded by extensive perilesional edema. An angiotomography was carried out, previous to the surgery, looking for irrigation and vascular compromise. The resection of 95% of the lesion was achieved (grade II of Simpson which included adjacent infiltrated dura madre and preserving the superior longitudinal sinus. Pathological results confirmed that it was an anaplastic meningioma grade III, with criterium for adyuvant treatment.

  13. Serial tomotherapy vs. MLC-IMRT (Multileaf Collimator Intensity Modulated Radiotherapy) for simultaneous boost treatment large intracerebral lesions

    International Nuclear Information System (INIS)

    Wolff, Dirk; Lohr, Frank; Mai, Sabine; Polednik, Martin; Wenz, Frederik; Dobler, Barbara

    2009-01-01

    Introduction: Recent data suggest that a radiosurgery boost treatment for up to three brain metastases in addition to whole brain radiotherapy (WBRT) is beneficial. Sequential treatment of multiple metastatic lesions is time-consuming and optimal normal tissue sparing is not trivial for larger metastases when separate plans are created and are only superimposed afterwards. Sequential Tomotherapy with noncoplanar arcs and Multi-field IMRT may streamline the process and enable easy simultaneous treatment. We compared plans for 2-3 intracerebral targets calculated with Intensity Modulated Radiotherapy (IMRT) based on treatment with MLC or sequential Tomotherapy using the Peacock-System. Treatment time was not to exceed 90 min on a linac with standart dose rate. MIMiC plans without treatment-time restrictions were created as a benchmark. Materials and methods: Calculations are based on a Siemens KD2 linac with a dose rate of 200 MU/min. Step-and-Shoot IMRT is performed with a standard MLC (2 x 29 leaves, 1 cm), serial Tomotherapy with the Multivane-Collimator MIMiC (NOMOS Inc. USA). Treatment plans are created with Corvus 5.0. To create plans with good conformity we chose a noncoplanar beam- and arc geometry for each approach (IMRT 4-, MIMiC 5-couch angles). The benchmark MIMiC plans with maximally steep dose gradients had 9 couch angles. For plan comparison reasons, 10Gy were prescribed to 90% of the PTV. Steepness of dose gradients, homogeneity and conformity were assessed by the following parameters: Volume encompassed by certain isodoses outside the target as well as homogeneity and conformity as indicated by Homogeneity- and Conformity-Index. Results: Plans without treatment-time restrictions had slightest dose to organ at risk (OAR), normal tissue and least Conformity-index. MIMiC- and MLC-IMRT based plans can be treated within the intended period of 90 min, all plans met the required dose. MLC based plans resulted in higher dose to organs at risk (OAR) and dose

  14. Assessment of improved organ at risk sparing for meningioma: Light ion beam therapy as boost versus sole treatment option

    International Nuclear Information System (INIS)

    Mock, Ulrike; Georg, Dietmar; Sölkner, Lukas; Suppan, Christian; Vatnitsky, Stanislav M.; Flechl, Birgit; Mayer, Ramona; Dieckmann, Karin; Knäusl, Barbara

    2014-01-01

    Purpose: To compare photons, protons and carbon ions and their combinations for treatment of atypical and anaplastical skull base meningioma. Material and methods: Two planning target volumes (PTV initial /PTV boost ) were delineated for 10 patients (prescribed doses 50 Gy(RBE) and 10 Gy(RBE)). Plans for intensity modulated photon (IMXT), proton (IMPT) and carbon ion therapy ( 12 C) were generated assuming a non-gantry scenario for particles. The following combinations were compared: IMXT + IMXT/IMPT/ 12 C; IMPT + IMPT/ 12 C; and 12 C + 12 C. Plan quality was evaluated by target conformity and homogeneity (CI, HI), V 95% , D 2% and D 50% and dose-volume-histogram (DVH) parameters for organs-at-risk (OAR). If dose escalation was possible, it was performed until OAR tolerance levels were reached. Results: CI was worst for IMXT. HI < 0.05 ± 0.01 for 12 C was significantly better than for IMXT. For all treatment options dose escalation above 60 Gy(RBE) was possible for four patients, but impossible for six patients. Compared to IMXT + IMXT, ion beam therapy showed an improved sparing for most OARs, e.g. using protons and carbon ions D 50% was reduced by more than 50% for the ipsilateral eye and the brainstem. Conclusion: Highly conformal IMPT and 12 C plans could be generated with a non-gantry scenario. Improved OAR sparing favors both sole 12 C and/or IMPT plans

  15. Effects of organ motion on IMRT treatments with segments of few monitor units

    International Nuclear Information System (INIS)

    Seco, J.; Sharp, G. C.; Turcotte, J.; Gierga, D.; Bortfeld, T.; Paganetti, H.

    2007-01-01

    Interplay between organ (breathing) motion and leaf motion has been shown in the literature to have a small dosimetric impact for clinical conditions (over a 30 fraction treatment). However, previous studies did not consider the case of treatment beams made up of many few-monitor-unit (MU) segments, where the segment delivery time (1-2 s) is of the order of the breathing period (3-5 s). In this study we assess if breathing compromises the radiotherapy treatment with IMRT segments of low number of MUs. We assess (i) how delivered dose varies, from patient to patient, with the number of MU per segment, (ii) if this delivered dose is identical to the average dose calculated without motion over the path of the motion, and (iii) the impact of the daily variation of the delivered dose as a function of MU per segment. The organ motion was studied along two orthogonal directions, representing the left-right and cranial-caudal directions of organ movement for a patient setup in the supine position. Breathing motion was modeled as sin(x), sin 4 (x), and sin 6 (x), based on functions used in the literature to represent organ motion. Measurements were performed with an ionization chamber and films. For a systematic study of motion effects, a MATLAB simulation was written to model organ movement and dose delivery. In the case of a single beam made up of one single segment, the dose delivered to point in a moving target over 30 fractions can vary up to 20% and 10% for segments of 10 MU and 20 MU, respectively. This dose error occurs because the tumor spends most of the time near the edges of the radiation beam. In the case of a single beam made of multiple segments with low MU, we observed 2.4%, 3.3%, and 4.3% differences, respectively, for sin(x), sin 4 (x), and sin 6 (x) motion, between delivered dose and motion-averaged dose for points in the penumbra region of the beam and over 30 fractions. In approximately 5-10% of the cases, differences between the motion-averaged dose

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

    Science.gov (United States)

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

    2016-02-01

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

  17. SU-E-T-593: Clinical Evaluation of Direct Aperture Optimization in Head/Neck and Prostate IMRT Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hosini, M [King Saud University Hospitals, Riyadh (Saudi Arabia); GALAL, M [Hermitage Medical Clinic, Dublin (Ireland); Emam, I [Ain Shams University, Cairo (France); Kamal, G; Algohary, M [Al Azhar University, Cairo (Egypt)

    2014-06-01

    Purpose: To investigate the planning and dosimetric advantages of direct aperture optimization (DAO) over beam-let optimization in IMRT treatment of head and neck (H/N) and prostate cancers. Methods: Five Head and Neck as well as five prostate patients were planned using the beamlet optimizer in Elekta-Xio ver 4.6 IMRT treatment planning system. Based on our experience in beamlet IMRT optimization, PTVs in H/N plans were prescribed to 70 Gy delivered by 7 fields. While prostate PTVs were prescribed to 76 Gy with 9 fields. In all plans, fields were set to be equally spaced. All cases were re-planed using Direct Aperture optimizer in Prowess Panther ver 5.01 IMRT planning system at same configurations and dose constraints. Plans were evaluated according to ICRU criteria, number of segments, number of monitor units and planning time. Results: For H/N plans, the near maximum dose (D2) and the dose that covers 95% D95 of PTV has improved by 4% in DAO. For organs at risk (OAR), DAO reduced the volume covered by 30% (V30) in spinal cord, right parotid, and left parotid by 60%, 54%, and 53% respectively. This considerable dosimetric quality improvement achieved using 25% less planning time and lower number of segments and monitor units by 46% and 51% respectively. In DAO prostate plans, Both D2 and D95 for the PTV were improved by only 2%. The V30 of the right femur, left femur and bladder were improved by 35%, 15% and 3% respectively. On the contrary, the rectum V30 got even worse by 9%. However, number of monitor units, and number of segments decreased by 20% and 25% respectively. Moreover the planning time reduced significantly too. Conclusion: DAO introduces considerable advantages over the beamlet optimization in regards to organs at risk sparing. However, no significant improvement occurred in most studied PTVs.

  18. Meningiomas in 2009: controversies and future challenges.

    Science.gov (United States)

    Campbell, Belinda A; Jhamb, Ashu; Maguire, John A; Toyota, Brian; Ma, Roy

    2009-02-01

    Meningiomas are the most common intracranial primary neoplasm in adults. Over recent years, interest in this clinically diverse group of tumors has intensified, bringing new questions and challenges to the fore, particularly in the fields of epidemiology, radiology, pathology, genetics, and treatment. Interest in modern meningioma research has been stimulated by the high tumor prevalence and the advances in technology. The incidence of meningiomas is climbing, and may indicate increased exposure to environmental risk factors or more sensitive diagnostic modalities. Technological advances have dramatically improved radiologic imaging and radiotherapy treatments, and further refinements are under investigation. Furthermore, the current era of tumor genetics and molecular biology is challenging translational researchers to discover new, targeted, therapeutic agents. This review is an update on the recent advances in the understanding of meningiomas and their management, and highlights pertinent research questions to be addressed in the future.

  19. Canine Intracranial Meningioma: Case report

    Directory of Open Access Journals (Sweden)

    José Ricardo Gomes de Carvalho

    2016-11-01

    Full Text Available ABSTRACT. Carvalho J.R.G., Vasconcellos C.H.C., Bastos I. P.B., Trajano F.L.C., Costa T.S. & Fernandes J.I [Canine Intracranial Meningioma: Case report.] Meningioma intracraniano canino: Relato de caso. Revista Brasileira de Medicina Veterinária, 38(supl. 3:1- 7, 2016. Programa de Pós-Graduação em Ciências Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, Seropédica, RJ 23.897-000, Brasil, E-mail: vetjulio@yahoo.com.br Intracranial neoplasms usually show their signals in a moderate way, revealing a long background of nonspecific signs, making the diagnosis more difficult. The meningioma is the most common intracranial neoplasm in dogs and cats. Along the years, the Veterinary Medicine has experienced important technological improvements, making it possible the diagnosis of a lot of diseases. Therefore, diseases considered not common in the past, started being diagnosed more frequently, for instance, brain lesions. The objective of this research is to report a case of intracranial meningioma in a Boxer dog that arrived at the Veterinary Hospital of the Federal Rural University of Rio de Janeiro, highlighting its clinical improvement, diagnosis and treatment.

  20. Preoperative embolization of gigantic meningioma

    International Nuclear Information System (INIS)

    Wang Hongsheng; Chen Huaqun; Dong Congsong; Li Wenhui; Dai Zhenyu; Chen Guozhi

    2006-01-01

    Objective: To evaluate the clinical efficacy of preoperative embolization in treatment of patients with gigantic meningioma. Methods: Fourteen cases of gigantic meningioma diameter from 6 to 11 cm were measured by CT and MRI scan. DSA manifested that they are vascularizd meningioma and showed the mainly feeding arteries. We used getation sponge to superselectively embilized the feeding arteries. All tumors were performed surgical excision 3-7 days after the embolization. Results: DSA showed the blood supplies in the tumors in 9 cases were completely blocked, and that in 5 cases were dramatically eliminated. All patients were operated 3-7 days after the embolization. During the operations the bleeding were dramatically decreased and the operation time was shortened compared with those in unembolized cases. It helps us remove the tumors easy and quickly from the attachments. No complication occurred during and after the operations. Conclusion: Preoperative embolization of gigantic meningioma is a useful and relatively safe method in helping surgicaly and completely excised of tumor with significant reduction of blood loss and operation time. (authors)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  2. Does the IMRT technique allow improvement of treatment plans (e.g. lung sparing) for lung cancer patients with small lung volume: a planning study

    International Nuclear Information System (INIS)

    Komosinska, K.; Kepka, L.; Gizynska, M.; Zawadzka, A.

    2008-01-01

    Aim: We evaluated whether intensity-modulated radiation therapy (IMRT) may offer any advantages in comparison with three-dimensional conformal radiotherapy (3D-CRT) for patients with small lung volume (SLV). Methods: Treatment planning was performed for 10 NSCLC patients with the smallest lung volume (mean: 2241 cc) among 200 patients from our database. For each patient 3D-CRT and IMRT plans were prepared. The goal was to deliver 66 Gy/33 fractions, with dose constraints: mean lung dose (MLD) < 20 Gy, V20 < 35%; spinal cord - Dmax < 45 Gy. When the plan could not meet these criteria, total dose was reduced. The 3D-CRT and IMRT plans were compared. We investigated: prescribed dose, coverage and conformity indices, MLD, V5-V65 in the lung. Results: In 4 out of 10 plans, 3D-CRT did not allow 66 Gy to be delivered, because of predicted pulmonary toxicity. These 4 cases included 3 for which we did not reach 66 Gy with IMRT; still, for these 3 plans the total dose was increased by an average of 9 Gy with IMRT in comparison with 3D-CRT. Coverage indices were similar for both techniques. Conformity indices were better for IMRT plans. MLD was lower in five IMRT and two 3D-CRT plans if equal doses were delivered. The decrease in MLD was seen for cases with large PTV and high PTV/lung volume ratio. Lung V5 was lower for all 3D-CRT plans, 47% vs. 57% for IMRT; V15 and above were larger for 3D-CRT Conclusion: In the planning study, IMRT seems to be a promising technique for cases with SLV, especially when associated with large PT V. (authors)

  3. Introduction: surgical management of skull base meningiomas.

    Science.gov (United States)

    Zada, Gabriel; Başkaya, Mustafa K; Shah, Mitesh V

    2017-10-01

    Meningiomas represent the most common primary intracranial neoplasm treated by neurosurgeons. Although multimodal treatment of meningiomas includes surgery, radiation-based treatments, and occasionally medical therapy, surgery remains the mainstay of treatment for most symptomatic meningiomas. Because of the intricate relationship of the dura mater and arachnoid mater with the central nervous system and cranial nerves, meningiomas can arise anywhere along the skull base or convexities, and occasionally even within the ventricular system, thereby mandating a catalog of surgical approaches that neurosurgeons may employ to individualize treatment for patients. Skull base meningiomas represent some of the most challenging pathology encountered by neurosurgeons, on account of their depth, invasion, vascularity, texture/consistency, and their relationship to bony anatomy, cranial nerves, and blood vessels. Resection of complex skull base meningiomas often mandates adequate bony removal to achieve sufficient exposure of the tumor and surrounding region, in order to minimize brain retraction and optimally identify, protect, control, and manipulate sensitive neurovascular structures. A variety of traditional skull base approaches has evolved to address complex skull base tumors, of which meningiomas are considered the paragon in terms of both complexity and frequency. In this supplemental video issue of Neurosurgical Focus, contributing authors from around the world provide instructional narratives demonstrating resection of a variety of skull base meningiomas arising from traditionally challenging origins, including the clinoid processes, tuberculum sellae, dorsum sellae, petroclival region, falco-tentorial region, cerebellopontine angle, and foramen magnum. In addition, two cases of extended endoscopic endonasal approaches for tuberculum sellae and dorsum sellae meningiomas are presented, representing the latest evolution in accessing the skull base for selected tumors

  4. Intraventricular trigonal meningioma: Neuronavigation? No, thanks!

    OpenAIRE

    Silva, Danilo O. A.; Matis, Georgios K.; Costa, Leonardo F.; Kitamura, Matheus A. P.; Birbilis, Theodossios A.; Azevedo Filho, Hildo R. C.

    2011-01-01

    Background: Most of the time meningiomas are benign brain tumors and surgical removal ensures cure in the vast majority of the cases. Thus, whenever possible, complete surgical resection should be the goal of the treatment. Methods: This is a report of our surgical technique for the operative resection of a trigonal meningioma in a resource-limited setting. The necessity of accurate and deep knowledge of the regional anatomy is outlined. Results: A 44-year-old male presented to our outpatient...

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

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, Jochen; Kremp, Katharina; Kremp, Stephanie; Palm, Jan; Ruebe, Christian [Saarland University Medical School, Department of Radiotherapy and Radiation Oncology, Homburg/Saar (Germany)

    2016-02-15

    The potential of intensity-modulated radiation therapy (IMRT) as opposed to three-dimensional conformal radiotherapy (3D-CRT) is analyzed for two different concepts of fluorodeoxyglucose positron emission tomography (FDG PET)-based target volume delineation in locally advanced non-small cell lung cancer (LA-NSCLC): involved-field radiotherapy (IF-RT) vs. elective nodal irradiation (ENI). Treatment planning was performed for 41 patients with LA-NSCLC, using four different planning approaches (3D-CRT-IF, 3D-CRT-ENI, IMRT-IF, IMRT-ENI). ENI included a boost irradiation after 50 Gy. For each plan, maximum dose escalation was calculated based on prespecified normal tissue constraints. The maximum prescription dose (PD), tumor control probability (TCP), conformal indices (CI), and normal tissue complication probabilities (NTCP) were analyzed. IMRT resulted in statistically significant higher prescription doses for both target volume concepts as compared with 3D-CRT (ENI: 68.4 vs. 60.9 Gy, p < 0.001; IF: 74.3 vs. 70.1 Gy, p < 0.03). With IMRT-IF, a PD of at least 66 Gy was achieved for 95 % of all plans. For IF as compared with ENI, there was a considerable theoretical increase in TCP (IMRT: 27.3 vs. 17.7 %, p < 0.00001; 3D-CRT: 20.2 vs. 9.9 %, p < 0.00001). The esophageal NTCP showed a particularly good sparing with IMRT vs. 3D-CRT (ENI: 12.3 vs. 30.9 % p < 0.0001; IF: 15.9 vs. 24.1 %; p < 0.001). The IMRT technique and IF target volume delineation allow a significant dose escalation and an increase in TCP. IMRT results in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels. (orig.) [German] Das Potenzial der intensitaetsmodulierten Strahlentherapie (IMRT) soll im Rahmen der FDG-PET basierten Bestrahlungsplanung des lokal fortgeschrittenen nichtkleinzelligen Bronchialkarzinoms (LA-NSCLC) fuer 2 Zielvolumenansaetze (Involved-Field-Bestrahlung, IF) sowie elektive Nodalbestrahlung (ENI) geprueft und mit der 3-D-konformalen Strahlentherapie (3-D

  6. Primary Intraorbital Ectopic Meningioma

    Science.gov (United States)

    Yokoyama, Tetsuo; Nishizawa, Shigeru; Sugiyama, Kenji; Yokota, Noki; Ohta, Seiji; Uemura, Kenichi; Hinokuma, Kaoru; Inenaga, Chikanori

    1999-01-01

    We report a case of intraorbital meningioma. Operative findings and histopathological examination revealed the tumoc to be meningothelial meningloma and to be located entirely outside the optic dura. This case demonstrates the occurrence of primary intraorbital ectopic meningioma, and the tumor was removed through a modified Dolenc approach. The primary intraorbital ectopic meningioma is discussed and the surgical approach to the orbital apex region is reviewed. ImagesFigure 1Figure 2Figure 4Figure 5 PMID:17171081

  7. Implementation of a method for patient-specific IMRT treatment verification using dynalog files; Aplicacion de un metodo para la verificacion de tratamientos de imrt sobre la anatomia del paciente utilizando archivos dynalog

    Energy Technology Data Exchange (ETDEWEB)

    Calama Santiago, J. A.; Infante Utrilla, M. A.; Lavado Rodriguez, M. E.

    2011-07-01

    The aim of this work is to implement a simple method of intensity modulated radiation therapy (IMRT) verification on the patient anatomy using dynalog files. Monitor units (MU) fraction and leaf positions, both planned and actually positioned during treatment, are sampled every 55 ms and stored in these files. This information was used in the treatment planning system to reconstruct the given fluence and to recalculate the absorbed dose in the patients CT, comparing absorbed dose distributions and histograms with those initially planned. Differences mainly appeared in areas with high absorbed dose gradients at the beginning and at the end of the radiation fields. These differences were lower than 3% in absorbed dose for most cases. No significant differences were found on dose-volume histograms. With proper linac and multileaf collimator commissioning, and a more stringent linac, treatment planning and record and verify system quality assurance program, this procedure allows patient-specific IMRT treatment verification, unlike conventional methods. (Author) 15 refs.

  8. Influence of the order of introduction of a set of objectives in IMRT treatment schedules prostate

    International Nuclear Information System (INIS)

    Maravilla Limorte, M.; Gomez Martin, C.; Alonso Iracheta, L.; Bejar Navarro, M. J.; Capuz Suarez, A. B.; Comenares Fernandez, R.; Moris Pablos, R.; Rot Sanjuan, M. J.

    2011-01-01

    The purpose of this paper is to analyze to what extent could influence the order in which you enter the target calculation algorithm of planning. For this, assesses the implications-both-dosimetric calculation as derived from the implementation of 3 IMRT optimization methods, which only differ in regard to the order of introduction of a fixed set of objectives.

  9. SU-F-T-440: The Feasibility Research of Checking Cervical Cancer IMRT Pre- Treatment Dose Verification by Automated Treatment Planning Verification System

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

    Purpose: To assess the preliminary feasibility of automated treatment planning verification system in cervical cancer IMRT pre-treatment dose verification. Methods: The study selected randomly clinical IMRT treatment planning data for twenty patients with cervical cancer, all IMRT plans were divided into 7 fields to meet the dosimetric goals using a commercial treatment planning system(PianncleVersion 9.2and the EclipseVersion 13.5). The plans were exported to the Mobius 3D (M3D)server percentage differences of volume of a region of interest (ROI) and dose calculation of target region and organ at risk were evaluated, in order to validate the accuracy automated treatment planning verification system. Results: The difference of volume for Pinnacle to M3D was less than results for Eclipse to M3D in ROI, the biggest difference was 0.22± 0.69%, 3.5±1.89% for Pinnacle and Eclipse respectively. M3D showed slightly better agreement in dose of target and organ at risk compared with TPS. But after recalculating plans by M3D, dose difference for Pinnacle was less than Eclipse on average, results were within 3%. Conclusion: The method of utilizing the automated treatment planning system to validate the accuracy of plans is convenientbut the scope of differences still need more clinical patient cases to determine. At present, it should be used as a secondary check tool to improve safety in the clinical treatment planning.

  10. A novel implementation of mARC treatment for non-dedicated planning systems using converted IMRT plans

    International Nuclear Information System (INIS)

    Dzierma, Yvonne; Nuesken, Frank; Licht, Norbert; Ruebe, Christian

    2013-01-01

    The modulated arc (mARC) technique has recently been introduced by Siemens as an analogue to VMAT treatment. However, up to now only one certified treatment planning system supports mARC planning. We therefore present a conversion algorithm capable of converting IMRT plans created by any treatment planning system into mARC plans, with the hope of expanding the availability of mARC to a larger range of clinical users and researchers. As additional advantages, our implementation offers improved functionality for planning hybrid arcs and provides an equivalent step-and-shoot plan for each mARC plan, which can be used as a back-up concept in institutions where only one linac is equipped with mARC. We present a feasibility study to outline a practical implementation of mARC plan conversion using Philips Pinnacle and Prowess Panther. We present examples for three different kinds of prostate and head-and-neck plans, for 6 MV and flattening-filter-free (FFF) 7 MV photon energies, which are dosimetrically verified. It is generally more difficult to create good quality IMRT plans in Pinnacle using a large number of beams and few segments. We present different ways of optimization as examples. By careful choosing the beam and segment arrangement and inversion objectives, we achieve plan qualities similar to our usual IMRT plans. The conversion of the plans to mARC format yields functional plans, which can be irradiated without incidences. Absolute dosimetric verification of both the step-and-shoot and mARC plans by point dose measurements showed deviations below 5% local dose, mARC plans deviated from step-and-shoot plans by no more than 1%. The agreement between GafChromic film measurements of planar dose before and after mARC conversion is excellent. The comparison of the 3D dose distribution measured by PTW Octavius 729 2D-Array with the step-and-shoot plans and with the TPS is well above the pass criteria of 90% of the points falling within 5% local dose and 3 mm distance

  11. Intensity modulated radiotherapy (IMRT in the treatment of children and Adolescents - a single institution's experience and a review of the literature

    Directory of Open Access Journals (Sweden)

    Huber Peter

    2009-09-01

    Full Text Available Abstract Background While IMRT is widely used in treating complex oncological cases in adults, it is not commonly used in pediatric radiation oncology for a variety of reasons. This report evaluates our 9 year experience using stereotactic-guided, inverse planned intensity-modulated radiotherapy (IMRT in children and adolescents in the context of the current literature. Methods Between 1999 and 2008 thirty-one children and adolescents with a mean age of 14.2 years (1.5 - 20.5 were treated with IMRT in our department. This heterogeneous group of patients consisted of 20 different tumor entities, with Ewing's sarcoma being the largest (5 patients, followed by juvenile nasopharyngeal fibroma, esthesioneuroblastoma and rhabdomyosarcoma (3 patients each. In addition a review of the available literature reporting on technology, quality, toxicity, outcome and concerns of IMRT was performed. Results With IMRT individualized dose distributions and excellent sparing of organs at risk were obtained in the most challenging cases. This was achieved at the cost of an increased volume of normal tissue receiving low radiation doses. Local control was achieved in 21 patients. 5 patients died due to progressive distant metastases. No severe acute or chronic toxicity was observed. Conclusion IMRT in the treatment of children and adolescents is feasible and was applied safely within the last 9 years at our institution. Several reports in literature show the excellent possibilities of IMRT in selective sparing of organs at risk and achieving local control. In selected cases the quality of IMRT plans increases the therapeutic ratio and outweighs the risk of potentially increased rates of secondary malignancies by the augmented low dose exposure.

  12. A cone beam CT-guided online plan modification technique to correct interfractional anatomic changes for prostate cancer IMRT treatment

    International Nuclear Information System (INIS)

    Fu Weihua; Yang Yong; Yue, Ning J; Heron, Dwight E; Huq, M Saiful

    2009-01-01

    The purpose of this work is to develop an online plan modification technique to compensate for the interfractional anatomic changes for prostate cancer intensity-modulated radiation therapy (IMRT) treatment based on daily cone beam CT (CBCT) images. In this proposed technique, pre-treatment CBCT images are acquired after the patient is set up on the treatment couch using an in-room laser with the guidance of the setup skin marks. Instead of moving the couch to rigidly align the target or re-planning using the CBCT images, we modify the original IMRT plan to account for the interfractional target motion and deformation based on the daily CBCT image feedback. The multileaf collimator (MLC) leaf positions for each subfield are automatically adjusted in the proposed algorithm based on the position and shape changes of target projection in the beam's eye view (BEV). Three typical prostate cases were adopted to evaluate the proposed technique, and the results were compared with those obtained with bony-structure-based rigid translation correction, prostate-based correction and CBCT-based re-planning strategies. The study revealed that the proposed modification technique is superior to the bony-structure-based and prostate-based correction techniques, especially when interfractional target deformation exists. Its dosimetric performance is closer to that of the re-planned strategy, but with much higher efficiency, indicating that the introduced online CBCT-guided plan modification technique may be an efficient and practical method to compensate for the interfractional target position and shape changes for prostate IMRT.

  13. Density variation of parotid glands during IMRT for head–neck cancer: Correlation with treatment and anatomical parameters

    International Nuclear Information System (INIS)

    Fiorino, Claudio; Rizzo, Giovanna; Scalco, Elisa; Broggi, Sara; Belli, Maria Luisa; Dell’Oca, Italo; Dinapoli, Nicola; Ricchetti, Francesco; Rodriguez, Aldo Mejia; Di Muzio, Nadia; Calandrino, Riccardo; Sanguineti, Giuseppe; Valentini, Vincenzo; Cattaneo, Giovanni Mauro

    2012-01-01

    Purpose: Measuring parotid density changes in patients treated with IMRT for head–neck cancer (HNC) and assessing correlation with treatment-related parameters. Patients and materials: Data of 84 patients treated with IMRT for different HNC were pooled from three institutions. Parotid deformation and average Hounsfield number changes (ΔHU) were evaluated through MVCT (with Helical Tomotherapy) or diagnostic kVCT images taken at the treatment start/end. Parotids were delineated in the first image and propagated to the last using a previously validated algorithm based on elastic registration. The correlation between ΔHU and several treatment-related parameters was tested; then, logistic uni- and multi-variate analyses taking “large” ΔHU as end-point were carried out. Due to the better image quality, analyses were repeated considering only kVCT data. Results: ΔHU was negative in 116/168 parotids (69%; for kVCT patients: 72/92, 78%). The average ΔHU was significantly different from zero (−7.3, 0.20–0.25 HU/fraction, p m ean), and with neck thickness variation; these correlations were much stronger for kVCT data. Logistic analyses considering ΔHU m ean < 0.68) and initial neck thickness to be the most predictive variables (p < 0.0005, AUC = 0.683; AUC = 0.776 for kVCT); the odd ratio of large vs moderate/small parotid deformation was 3.8 and 8.0 for the whole and the kVCT population respectively. Conclusions: Parotid density reduced in most patients during IMRT and this phenomenon was highly correlated with parotid deformation. The individual assessment of density changes was highly reliable just with diagnostic KvCT. Density changes should be considered as an additional objective measurement of early parotid radiation-induced modifications; further research is warranted.

  14. Congenital extracranial meningioma

    International Nuclear Information System (INIS)

    Wong, H.F.; Ng, S.H.; Wai, Y.Y.; Wan, Y.L.; Kong, M.S.

    1995-01-01

    The authors report a case of congenital meningioma in a newborn. This tumour is extremely rare and only six cases have been reported in the literature. Those reported cases were mainly intracranial. This is the first case of a neonatal extracranial meningioma that was evaluated preoperatively by computed tomography and magnetic resonance imaging. (orig.)

  15. Intensity modulated radiotherapy (IMRT) for patients of the Brazilian unified health system (SUS): an analysis of 508 treatments two years after the technique implementation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Harley Francisco de; Trevisan, Felipe Amstalden; Bighetti, Viviane Marques; Guimaraes, Flavio da Silva; Amaral, Leonardo Lira; Barbi, Gustavo Lazaro; Borges, Leandro Federiche; Peria, Fernanda Maris, E-mail: harley@fmrp.usp.br [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2014-11-15

    Objective: the offering of high-technology radiotherapy to the population assisted by the Brazilian unified health system (SUS) is limited since it is not included in the system’s list of procedures and, many times, because of the insufficient installed capacity and lack of specialized human resources. Thus the access to intensity-modulated radiotherapy (IMRT) is restricted to few centers in Brazil. The present study is aimed at presenting the characteristics of the first 508 cases treated with IMRT during the first years after the technique implementation in a university hospital. Materials and methods: the first consecutive 508 cases of IMRT treatment completed in the period from May/2011 to September/2013 were reviewed. Static multi leaf was the technique employed. Results: amongst 4,233 treated patients, 12.5% were submitted to IMRT. Main indications for the treatment included cancers located in the skull, head and neck and prostate. Intensity modulated radiotherapy was utilized in about 30% of cranial and 50% of prostate treatments. Treatment toxicity was observed in 4% of the patients. Conclusion: because of restricted access to radiotherapy in addition to lack of coverage for the procedure, IMRT indications for SUS patients should be based on institutional clinical protocols, with special attention to the reduction of toxicity. (author)

  16. A new method for verification of IMRT treatments on patient geometry files using DYNALOG; Un metodo para la verficacion de tratamientos de IMRT sobre la geometria del paciente utilizando los archivos Dynalog

    Energy Technology Data Exchange (ETDEWEB)

    Infante Utrilla, M. A.; Calama Santiago, J. A.; Lavado Rodriguez, M. E.

    2011-07-01

    The aim of this work is to implement a novel method of verification of IMRT treatments, using this information to reconstruct the flow in the scheduler and calculate the dose, comparing dose distributions in 2D and 3D histograms obtained with the initials. This procedure lacks the limitations and uncertainties of the dosimetric detectors used in the verification of model (ionization chamber, film, etc..) Or ILD, also allowing to quantify the differences on the patient.

  17. Anaplastic meningioma: The dark side of meningiomas

    Directory of Open Access Journals (Sweden)

    Andreea Cioca

    2017-06-01

    Full Text Available Anaplastic meningioma is a rare malignant tumor of the meninges, with a very aggressive behavior and a grim prognosis. Here we report a case of a 64-year old man which presented to the neurosurgery department with motor deficit in the right hemi–body, loss of speech and disorientation. Magnetic resonance imaging detected a mass located in the left frontal lobe that measured 7/8/7 cm, leading to the conclusion that surgery is necessary. Microscopic examination of the tumor showed great number of hypercellular areas with a high mitotic index, and focal necrosis with psammoma bodies. Using a panel of antibodies such as EMA, vimentin, CD34 GFAP, pancytokeratin and Ki67, we concluded that he final diagnosis was anaplastic meningioma, WHO grade III. Due to its morphological similarity with other tumors, the diagnosis of anaplastic meningioma may be challenging.

  18. MULTIPLE SPINAL CANAL MENINGIOMAS

    Directory of Open Access Journals (Sweden)

    Nandigama Pratap Kumar

    2016-10-01

    Full Text Available BACKGROUND Meningiomas of the spinal canal are common tumours with the incidence of 25 percent of all spinal cord tumours. But multiple spinal canal meningiomas are rare in compare to solitary lesions and account for 2 to 3.5% of all spinal meningiomas. Most of the reported cases are both intra cranial and spinal. Exclusive involvement of the spinal canal by multiple meningiomas are very rare. We could find only sixteen cases in the literature to the best of our knowledge. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for single lesion. We analysed the literature, with illustration of our case. MATERIALS AND METHODS In September 2016, we performed a literature search for multiple spinal canal meningiomas involving exclusively the spinal canal with no limitation for language and publication date. The search was conducted through http://pubmed.com, a wellknown worldwide internet medical address. To the best of our knowledge, we could find only sixteen cases of multiple meningiomas exclusively confined to the spinal canal. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for solitary intradural extra medullary spinal canal meningioma at D4-D6 level, again presented with spastic quadriparesis of two years duration and MRI whole spine demonstrated multiple intradural extra medullary lesions, which were excised completely and the histopathological diagnosis was transitional meningioma. RESULTS Patient recovered from his weakness and sensory symptoms gradually and bladder and bowel symptoms improved gradually over a period of two to three weeks. CONCLUSION Multiple

  19. Experience in the treatment of IMRT in prostate cancer. Planning, dosimetry and quality control; Experiencia en el tratamiento de IMRT en cancer de prostata. Planificacion, dosimetria y control de calidad

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Barrado, A.; Garcia Vicente, F.; Fernandez Bedoya, V.; Bermudez Luna, R.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2011-07-01

    The aim of this study is to review the treatment of prostate cancer at our center. A description of the entire procedure, involving clinical dosimetry, and procedures for verification of treatment, including physical dosimetry and parallel computing system MSure (Standard Imaging, Inc., Middleton) as part of these procedures. This system is based on the model published by trifuente Yang et al. (Yang et al. 2002) for testing treatments regarding the number of monitor unit (MU) given. In addition, this software has a module for the testing of treatments for intensity modulated radiotherapy (IMRT), which will be analyzed in this study.

  20. Evaluation of IMRT plans for prostate treatment using energies of 6 MV and 15 MV; Avaliacao de planejamentos de IMRT para tratamento de prostata utilizando energias de 6 MV e 15 MV

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Lucas Francisco C.; Silva, Murilo C. da; Silveira, Paula J.; Flosi, Adriana A.; Boccaletti, Karina W., E-mail: mcollete@gmail.com [A. C. Camargo Cancer Center, Sao Paulo, SP (Brazil). Servico de Radioterapia

    2013-08-15

    This study aims to evaluate and compare radiotherapy plans with intensity-modulated radiation therapy (IMRT) for prostate cancer treatments optimized for photon energies of 6 MV and 15 MV. We retrospectively evaluated 29 patients with prostate cancer, planned with IMRT technique with prescribed dose of 78 Gy. The initial plan was done for the two photon energies, keeping the same optimization parameters and comparing maximum, minimum and modal PTV doses, conformity and homogeneity indexes, dose gradients, isodoses volumes of 30, 40, 50, 60, and 70 Gy, and the total number of monitor units. It was found that the plans are equivalent regarding higher isodose volumes, conformity and homogeneity indexes, maximum, minimum and modal PTV doses. However, for 6 MV plans there was a considerable increase in both number of monitor units and volume lower isodose volumes, especially the 30 Gy. (author)

  1. Acceptance for clinical use of a treatment planning system with IMRT and VMAT techniques; Aceptacion para uso clinico de un sistema de planificacion de tratamientos con tecnicas de IMRT y VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Serna, A.; Puchades, V.; Mata, F.

    2011-07-01

    Purpose: In this work the set of measurements and results to test the reliability of the calculated absorbed dose by our treatment planning system (Tps) for intensity modulated radiation therapy (Imr) and volumetric modulated arc therapy (Vat) is reported. Method: A set of measures was performed, both point and planar absorbed dose, selecting a set of conventional and Imr and Vat treatment fields. A gamma criteria 3 mm distance to agreement and 3% dose difference (referred to the maximum dose) was used for the planar distribution analysis, using a 10% of maximum dose as threshold. Based on this set of measures the confidence limits were calculated for the Imr and VMAT plans, and compared with the reference values given in AAPM TG119 document. Results: The average percentage deviation of point dose measures was lower than 0.5% for conventional fields and lower than 1% for IMRT and VMAT fields. Calculated confidence limits were 3.6% and 4.6% for point dose and almost zero for planar dose distributions, for IMRT and VMAT respectively. Conclusions: Our confidence levels improve significantly the AAPM TG119 reference levels both for point and planar doses, thus ensuring the reliability of the TPS performing IMRT and VMAT dose calculations. (Author) 17 refs.

  2. High-precision radiotherapy for meningiomas. Long-term results and patient-reported outcome (PRO)

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, Kerstin A.; Fischer, Hanna; Combs, Stephanie E. [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Helmholtz Zentrum Muenchen (HMGU), Institute for Innovative Radiotherapy (iRT), Department of Radiation Sciences DRS, Neuherberg (Germany); Oechnser, Markus [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Zimmer, Claus [Technical University of Munich (TUM), Department of Neuroradiology, Munich (Germany); Meyer, Bernhard [Technical University of Munich (TUM), Department of Neurosurgery, Munich (Germany)

    2017-11-15

    To evaluate long-term outcome after high-precision radiotherapy (RT) of meningioma patients in terms of survival and side effects. We analyzed 275 meningioma cases: 147 low-grade and 43 high-grade meningiomas (WHO II: n = 40, III: n = 3). In all, 85 patients had no pathologically confirmed histology but were determined as low-grade based on multimodal imaging. Surgery was performed in 183 cases. RT was delivered as either radiosurgery (RS, n = 16), fractionated stereotactic radiotherapy (FSRT, n = 241), or intensity-modulated radiation therapy (IMRT, n = 18). Of 218 patients contacted for patient-reported-outcome (PRO), 207 responded (95%). Median follow-up was 7.2 years. For low-grade meningioma the survival rate (OS) was 97% at 3 years, 85% at 10 years, and 64% at 15 years, for atypical meningioma 91% at 3 years, 62% at 10 years, and 50% at 15 years. Local control rate (PFS) for low-grade meningioma was 91% at 3 years, 87% at 5 years, and 86% at 10 years, for atypical cases 67% at 3 years and 55% at 5 years. Of all, 3.0% of patients reported worsened or new symptoms grade ≥3 during RT and the first 6 months thereafter; 17.5% reported a deterioration after more than 2 years. We found the prognostic factors tumor volume and age significantly influencing OS and PFS. Complemented by PRO, we found long-term low toxicity rates in addition to excellent local control. Thus, due to the beneficial risk-benefit profile of benign and high-risk meningiomas, RT should be performed as adjuvant treatment and should not be postponed until tumor progression. (orig.) [German] Langzeitergebnisse nach Hochpraezisionsstrahlentherapie (RT) von Patienten mit Meningeomen hinsichtlich Ueberleben und Nebenwirkungen. Es wurden 275 Meningeomfaelle untersucht: 145 benigne (WHO I), 40 atypische (WHO II) und 3 anaplastische (WHO III) Meningeome; bei 85 Patienten bestand keine histologische Sicherung. Voroperiert waren 183 Faelle (67 %). Bei 16 Patienten wurde eine Radiochirurgie (RS

  3. SU-E-T-16: A Hybrid VMAT/IMRT Technique for the Treatment of Nasopharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Zhao, N; Yang, R; Wang, J

    2014-01-01

    Purpose: To investigate a Hybrid VMAT/IMRT technique which combines volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods: 2 full arcs VMAT, 9-field IMRT and Hybrid VMAT/IMRT plans were created for 10 patients with NPC. The Hybrid VMAT/IMRT technique consisted of 1 full VMAT arc and 7 IMRT fields. The dose distribution of planning target volume (PTV) and organs at risk (OARs) for Hybrid VMAT/IMRT was compared with IMRT and VMAT. The monitor units (MUs) were also evaluated. Results: The Hybrid VMAT/IMRT technique significantly improved target dose homogeneity compared with IMRT and VMAT for PTV70 and PTV54. For PTV70 and PTV60, the Hybrid VMAT/IMRT technique significantly improved target dose conformity compared with IMRT (0.62 vs 0.47; p<0.05 and 0.64 vs 0.58; p<0.05, respectively) and VMAT (0.62 vs 0.43; p<0.05 and 0.64 vs 0.6; p<0.05, respectively). The near maximum dose (D2%) of temporomandibular joint (TMJ), temporal lobe and mandible for Hybrid plans were 5.5%, 7.9% and 5.2% lower than IMRT plans (p<0.05). The mean dose of TMJ, temporal lobe, mandible and unspecified tissue for Hybrid plans were 12.8%, 11.4%, 4.2% and 4.1% lower than IMRT plans (p<0.05). The mean dose of right parotid, mandible and unspecified tissue for Hybrid plans were 3.3%, 2.4% and 3.1% lower than VMAT plans (p<0.05). The mean MUs needed for IMRT, VMAT and Hybrid plans were 2256, 507 and 1394, respectively. Conclusion: Hybrid VMAT/IMRT technique significantly improved the target dose homogeneity and conformity compared with IMRT and VMAT and reduced the dose of OARs and unspecified tissue compared with IMRT with fewer MUs. Compared with VMAT, Hybrid VMAT/IMRT technique can better protect parotid gland, mandible and unspecified tissue. Ruijie Yang was funded by the grant project: National Natural Science Foundation of China (No. 81071237). Other authors have no competing interest for this work

  4. SU-E-T-16: A Hybrid VMAT/IMRT Technique for the Treatment of Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, N; Yang, R; Wang, J [Peking University Third Hospital, Beijing, Beijing (China)

    2014-06-01

    Purpose: To investigate a Hybrid VMAT/IMRT technique which combines volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods: 2 full arcs VMAT, 9-field IMRT and Hybrid VMAT/IMRT plans were created for 10 patients with NPC. The Hybrid VMAT/IMRT technique consisted of 1 full VMAT arc and 7 IMRT fields. The dose distribution of planning target volume (PTV) and organs at risk (OARs) for Hybrid VMAT/IMRT was compared with IMRT and VMAT. The monitor units (MUs) were also evaluated. Results: The Hybrid VMAT/IMRT technique significantly improved target dose homogeneity compared with IMRT and VMAT for PTV70 and PTV54. For PTV70 and PTV60, the Hybrid VMAT/IMRT technique significantly improved target dose conformity compared with IMRT (0.62 vs 0.47; p<0.05 and 0.64 vs 0.58; p<0.05, respectively) and VMAT (0.62 vs 0.43; p<0.05 and 0.64 vs 0.6; p<0.05, respectively). The near maximum dose (D2%) of temporomandibular joint (TMJ), temporal lobe and mandible for Hybrid plans were 5.5%, 7.9% and 5.2% lower than IMRT plans (p<0.05). The mean dose of TMJ, temporal lobe, mandible and unspecified tissue for Hybrid plans were 12.8%, 11.4%, 4.2% and 4.1% lower than IMRT plans (p<0.05). The mean dose of right parotid, mandible and unspecified tissue for Hybrid plans were 3.3%, 2.4% and 3.1% lower than VMAT plans (p<0.05). The mean MUs needed for IMRT, VMAT and Hybrid plans were 2256, 507 and 1394, respectively. Conclusion: Hybrid VMAT/IMRT technique significantly improved the target dose homogeneity and conformity compared with IMRT and VMAT and reduced the dose of OARs and unspecified tissue compared with IMRT with fewer MUs. Compared with VMAT, Hybrid VMAT/IMRT technique can better protect parotid gland, mandible and unspecified tissue. Ruijie Yang was funded by the grant project: National Natural Science Foundation of China (No. 81071237). Other authors have no competing interest for this work.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  6. SU-E-T-541: Bolus Effect of Thermoplastic Masks in IMRT and VMAT Head and Neck Treatments

    International Nuclear Information System (INIS)

    Zhen, H; Nedzi, L; Chen, S; Jiang, S; Zhao, B

    2014-01-01

    Purpose: To quantitatively evaluate the bolus effect of thermoplalstic mask on patient skin dose during multi-field IMRT and VMAT treatment. Methods: The clinically approved target contours for five head and neck patients were deformably registered to an anthropomorphic Rando phantom. Two plans: Multifield IMRT plan with 7-9 beams and VMAT plan with 2-4 arcs were created for each patient following same dose constraints. 3mm skin was excluded from PTVs but not constrained during optimization. The prescription dose was 200-220 cGy/fraction. A thermoplastic head and shoulder mask was customized for the Rando phantom. Each plan was delivered to the phantom twice with and without mask. During each delivery, two rectangular strips of EBT3 films (1cm x 6.8cm) were placed across the anterior upper and lower neck near PTVs to measure the surface dose. For consistency films were positioned at same locations for same patient. A total of 8 film strips were obtained for each patient. Film dose was calibrated in the range of 0-400cGy on the day of plan delivery. For dose comparison 3 regions of interests (ROIs) of 1×1 cm 2 were selected at left, right and middle part of each film, resulting in 6 point doses at each plan delivery. Results: The films without mask show relatively uniform dose distribution while those with mask clearly show mesh pattern of mask, usually indicating an increase in skin dose. On average the increase in skin dose over all ROIs with mask was 31.9%(±14.8%) with a range of 11.4%- 58.4%. There is no statistically significant difference (p=0.44) between skin dose increase in VMAT (30.8%±15.3%) and IMRT delivery (33.0%±14.9%). Conclusion: Thermoplastic immobilization masks increase surface dose for HN patient by around 30%. The magnitude is comparable between multi-field IMRT and VMAT. Radiochromic EBT3 film serves as an effective tool to quantify bolus effect

  7. A systematic benchmark method for analysis and comparison of IMRT treatment planning algorithms.

    Science.gov (United States)

    Mayo, Charles S; Urie, Marcia M

    2003-01-01

    Tools and procedures for evaluating and comparing different intensity-modulated radiation therapy (IMRT) systems are presented. IMRT is increasingly in demand and there are numerous systems available commercially. These programs introduce significantly different software to dosimetrists and physicists than conventional planning systems, and the options often seem initially overwhelmingly complex to the user. By creating geometric target volumes and critical normal tissues, the characteristics of the algorithms may be investigated, and the influence of the different parameters explored. Overall optimization strategies of the algorithm may be characterized by treating a square target volume (TV) with 2 perpendicular beams, with and without heterogeneities. A half-donut (hemi-annulus) TV with a "donut hole" (central cylinder) critical normal tissue (CNT) on a CT of a simulated quality assurance phantom is suggested as a good geometry to explore the IMRT algorithm parameters. Using this geometry, the order of varying parameters is suggested. First is to determine the effects of the number of stratifications of optimized intensity fluence on the resulting dose distribution, and selecting a fixed number of stratifications for further studies. To characterize the dose distributions, a dose-homogeneity index (DHI) is defined as the ratio of the dose received by 90% of the volume to the minimum dose received by the "hottest" 10% of the volume. The next step is to explore the effects of priority and penalty on both the TV and the CNT. Then, choosing and fixing these parameters, the effects of varying the number of beams can be looked at. As well as evaluating the dose distributions (and DHI), the number of subfields and the number of monitor units required for different numbers of stratifications and beams can be evaluated.

  8. Meningioma Causing Visual Impairment: Outcomes and Toxicity After Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maclean, Jillian, E-mail: jillian.maclean@uclh.nhs.uk [Radiotherapy Department, University College London Hospital, London (United Kingdom); Fersht, Naomi [Radiotherapy Department, University College London Hospital, London (United Kingdom); Bremner, Fion [Neuro-Ophthalmology Department, National Hospital for Neurology and Neurosurgery, London (United Kingdom); Stacey, Chris; Sivabalasingham, Suganya [Radiotherapy Department, University College London Hospital, London (United Kingdom); Short, Susan [Radiotherapy Department, University College London Hospital, London (United Kingdom); Leeds Institute of Molecular Medicine, St James University Hospital, Leeds (United Kingdom)

    2013-03-15

    Purpose: To evaluate ophthalmologic outcomes and toxicity of intensity modulated radiation therapy (IMRT) in patients with meningiomas causing visual deficits. Methods and Materials: A prospective observational study with formal ophthalmologic and clinical assessment of 30 consecutive cases of meningioma affecting vision treated with IMRT from 2007 to 2011. Prescriptions were 50.4 Gy to mean target dose in 28 daily fractions. The median follow-up time was 28 months. Twenty-six meningiomas affected the anterior visual pathway (including 3 optic nerve sheath meningiomas); 4 were posterior to the chiasm. Results: Vision improved objectively in 12 patients (40%). Improvements were in visual field (5/16 patients), color vision (4/9 patients), acuity (1/15 patients), extraocular movements (3/11 patients), ptosis (1/5 patients), and proptosis (2/6 patients). No predictors of clinical response were found. Two patients had minor reductions in tumor dimensions on magnetic resonance imaging, 1 patient had radiological progression, and the other patients were stable. One patient experienced grade 2 keratitis, 1 patient had a minor visual field loss, and 5 patients had grade 1 dry eye. Conclusion: IMRT is an effective method for treating meningiomas causing ophthalmologic deficits, and toxicity is minimal. Thorough ophthalmologic assessment is important because clinical responses often occur in the absence of radiological change.

  9. Meningiomas after cranial radiotherapy for childhood cancer: a single institution experience.

    Science.gov (United States)

    Felicetti, Francesco; Fortunati, Nicoletta; Garbossa, Diego; Biasin, Eleonora; Rudà, Roberta; Daniele, Dino; Arvat, Emanuela; Corrias, Andrea; Fagioli, Franca; Brignardello, Enrico

    2015-07-01

    Childhood cancer survivors (CCS) treated with cranial radiation therapy (CRT) are at risk of developing meningiomas. The aim of this study was to evaluate the cumulative incidence of meningiomas in a cohort of CCS who previously underwent CRT. We considered all CCS who received CRT and were followed up at the "Transition Unit for Childhood Cancer Survivors" in Turin. Even though asymptomatic, they had at least one brain computed tomography or magnetic resonance imaging performed at a minimum interval of 10 years after treatment for pediatric cancer. We identified 90 patients (median follow-up 24.6 years). Fifteen patients developed meningioma (median time from pediatric cancer, 22.5 years). In four patients, it was suspected on the basis of neurological symptoms (i.e., headache or seizures), whereas all other cases, including five giant meningiomas, were discovered in otherwise asymptomatic patients. Multiple meningiomas were discovered in four CCS. Ten patients underwent surgical resection. An atypical meningioma (grade II WHO) was reported in four patients. One patient with multiple meningiomas died for a rapid growth of the intracranial lesions. A second neoplasm (SN) other than meningioma was diagnosed in five out of the 15 patients with meningioma and in ten out of the 75 CCS without meningioma. Cox multivariate analysis showed that the occurrence of meningioma was associated with the development of other SNs, whereas age, sex, or CRT dose had no influence. CCS at risk of the development of meningioma deserve close clinical follow-up, especially those affected by other SNs.

  10. Effect of MLC leaf width on the planning and delivery of SMLC IMRT using the CORVUS inverse treatment planning system

    International Nuclear Information System (INIS)

    Burmeister, Jay; McDermott, Patrick N.; Bossenberger, Todd; Ben-Josef, Edgar; Levin, Kenneth; Forman, Jeffrey D.

    2004-01-01

    This study investigates the influence of multileaf collimator (MLC) leaf width on intensity modulated radiation therapy (IMRT) plans delivered via the segmented multileaf collimator (SMLC) technique. IMRT plans were calculated using the Corvus treatment planning system for three brain, three prostate, and three pancreas cases using leaf widths of 0.5 and 1 cm. Resulting differences in plan quality and complexity are presented here. Plans calculated using a 1 cm leaf width were chosen over the 0.5 cm leaf width plans in seven out of nine cases based on clinical judgment. Conversely, optimization results revealed a superior objective function result for the 0.5 cm leaf width plans in seven out of the nine comparisons. The 1 cm leaf width objective function result was superior only for very large target volumes, indicating that expanding the solution space for plan optimization by using narrower leaves may result in a decreased probability of finding the global minimum. In the remaining cases, we can conclude that we are often not utilizing the objective function as proficiently as possible to meet our clinical goals. There was often no apparent clinically significant difference between the two plans, and in such cases the issue becomes one of plan complexity. A comparison of plan complexity revealed that the average 1 cm leaf width plan required roughly 60% fewer segments and over 40% fewer monitor units than required by 0.5 cm leaf width plans. This allows a significant decrease in whole body dose and total treatment time. For very complex IMRT plans, the treatment delivery time may affect the biologically effective dose. A clinically significant improvement in plan quality from using narrower leaves was evident only in cases with very small target volumes or those with concavities that are small with respect to the MLC leaf width. For the remaining cases investigated in this study, there was no clinical advantage to reducing the MLC leaf width from 1 to 0.5 cm. In

  11. Primary mediastinal atypical meningioma: Report of a case and literature review

    Directory of Open Access Journals (Sweden)

    Mogi Akira

    2012-01-01

    Full Text Available Abstract Meningiomas are common neoplasms arising from the central nervous system meninges. On the other hand, primary ectopic meningiomas are extremely rare and usually limited to the head and neck region or to the paravertebral soft tissues. Their occurrence in the mediastinum is even rarer. Until now, only 4 cases of primary mediastinal meningioma have been reported in the literature searched on Medline. Because of its rarity and intriguing pathogenesis, we report here a case of primary mediastinal meningioma that was treated by surgical resection. The clinical features, treatment, pathological findings, and prognosis are analyzed, and the literature on ectopic meningioma is reviewed.

  12. SU-F-T-388: Comparison of Biophysical Indices in Hippocampal-Avoidance Whole Brain VMAT and IMRT Radiation Therapy Treatment Plans

    International Nuclear Information System (INIS)

    Kendall, E; Ahmad, S; Algan, O; Higby, C; Hossain, S

    2016-01-01

    Purpose: To compare biophysical indices of Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) treatment plans for whole brain radiation therapy following the NRG-CC001 protocol. Methods: In this retrospective study, a total of fifteen patients were planned with Varian Eclipse Treatment Planning System using VMAT (RapidArc) and IMRT techniques. The planning target volume (PTV) was defined as the whole brain volume excluding a uniform three-dimensional 5mm expansion of the hippocampus volume. Prescribed doses in all plans were 30 Gy delivered over 10 fractions normalized to a minimum of 95% of the target volume receiving 100% of the prescribed dose. The NRG Oncology protocol guidelines were followed for contouring and dose-volume constraints. A single radiation oncologist evaluated all treatment plans. Calculations of statistical significance were performed using Student’s paired t-test. Results: All VMAT and IMRT plans met the NRG-CC001 protocol dose-volume criteria. The average equivalent uniform dose (EUD) for the PTV for VMAT vs. IMRT was respectively (19.05±0.33 Gy vs. 19.38±0.47 Gy) for α/β of 2 Gy and (19.47±0.30 Gy vs. 19.84±0.42 Gy) for α/β of 10 Gy. For the PTV, the average mean and maximum doses were 2% and 5% lower in VMAT plans than in IMRT plans, respectively. The average EUD and the normal tissue complication probability (NTCP) for the hippocampus in VMAT vs. IMRT plans were (15.28±1.35 Gy vs. 15.65±0.99 Gy, p=0.18) and (0.305±0.012 Gy vs. 0.308±0.008 Gy, p=0.192), respectively. The average EUD and NTCP for the optic chiasm were both 2% higher in VMAT than in IMRT plans. Conclusion: Though statistically insignificant, VMAT plans indicate a lower hippocampus EUD than IMRT plans. Also, a small variation in NTCP was found between plans.

  13. SU-F-T-388: Comparison of Biophysical Indices in Hippocampal-Avoidance Whole Brain VMAT and IMRT Radiation Therapy Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, E; Ahmad, S; Algan, O; Higby, C; Hossain, S [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To compare biophysical indices of Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) treatment plans for whole brain radiation therapy following the NRG-CC001 protocol. Methods: In this retrospective study, a total of fifteen patients were planned with Varian Eclipse Treatment Planning System using VMAT (RapidArc) and IMRT techniques. The planning target volume (PTV) was defined as the whole brain volume excluding a uniform three-dimensional 5mm expansion of the hippocampus volume. Prescribed doses in all plans were 30 Gy delivered over 10 fractions normalized to a minimum of 95% of the target volume receiving 100% of the prescribed dose. The NRG Oncology protocol guidelines were followed for contouring and dose-volume constraints. A single radiation oncologist evaluated all treatment plans. Calculations of statistical significance were performed using Student’s paired t-test. Results: All VMAT and IMRT plans met the NRG-CC001 protocol dose-volume criteria. The average equivalent uniform dose (EUD) for the PTV for VMAT vs. IMRT was respectively (19.05±0.33 Gy vs. 19.38±0.47 Gy) for α/β of 2 Gy and (19.47±0.30 Gy vs. 19.84±0.42 Gy) for α/β of 10 Gy. For the PTV, the average mean and maximum doses were 2% and 5% lower in VMAT plans than in IMRT plans, respectively. The average EUD and the normal tissue complication probability (NTCP) for the hippocampus in VMAT vs. IMRT plans were (15.28±1.35 Gy vs. 15.65±0.99 Gy, p=0.18) and (0.305±0.012 Gy vs. 0.308±0.008 Gy, p=0.192), respectively. The average EUD and NTCP for the optic chiasm were both 2% higher in VMAT than in IMRT plans. Conclusion: Though statistically insignificant, VMAT plans indicate a lower hippocampus EUD than IMRT plans. Also, a small variation in NTCP was found between plans.

  14. Poster – 12: Radiological assessment of the secondary barrier shielding for IMRT treatments delivered through patient inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, Syed Abdul; Ahmad, Syed Bilal; Mirza, Sikander Majid [Pakistan Institute of Engineering and Applied Science, Nilore, Islamabad, Pakistan, Sunnybrook Health Sciences Center, Toronto, ON, Canada & Pakistan Institute of Engineering and Applied Science, Nilore, Islamabad, Pakistan, Pakistan Institute of Engineering and Applied Science, Nilore, Islamabad (Pakistan)

    2016-08-15

    Purpose: To assess the impact of radiation treatment delivery through patient inhomogeneities on the secondary barrier shielding requirements in IMRT treatments using Monte Carlo Simulations. Materials and Methods: Scatter factors were calculated at a distance of 1m from the center of a virtual phantom in Geant4.10.01. Phantom (30×30×30 cm{sup 3}) was inserted with lung (30×30×8 cm{sup 3}), stainless steel (5×5×5 cm{sup 3}) and aluminum (5×5×5 cm{sup 3}) to represent the inhomogeneities. Scatter factor was defined according to the NCRP-151 recommendations and was calculated for angles of 3° to 120° with respect to the beam’s central axis. A virtual radiation source, with energy sampled from a histogram representing 6 MV FFF beam, was used for irradiation with a field size of 15×15 cm{sup 2} and SSD of 100 cm. Results: Irradiation through the inhomogeneity affects the patient scattered dose. For high Z material inhomogeneities the scattered dose is reduced due to significant attenuation of the primary radiation. On the other hand if the inhomogeneity is a low Z material such as lung the scattered dose is higher by a maximum of 26%. The average increase in scatter factors for the lung phantom was 17% for angles between 3° and 63° compared to the homogeneous water phantom. Conclusions: In IMRT type treatments delivered through low density patient inhomogeneities (lung) the scattered dose increases significantly. Considering a large proportion of patients receiving radiation therapy for lung cancers the increase in the scattered dose should be incorporated in the shielding calculations for the secondary barriers.

  15. Poster – 12: Radiological assessment of the secondary barrier shielding for IMRT treatments delivered through patient inhomogeneities

    International Nuclear Information System (INIS)

    Haseeb, Syed Abdul; Ahmad, Syed Bilal; Mirza, Sikander Majid

    2016-01-01

    Purpose: To assess the impact of radiation treatment delivery through patient inhomogeneities on the secondary barrier shielding requirements in IMRT treatments using Monte Carlo Simulations. Materials and Methods: Scatter factors were calculated at a distance of 1m from the center of a virtual phantom in Geant4.10.01. Phantom (30×30×30 cm 3 ) was inserted with lung (30×30×8 cm 3 ), stainless steel (5×5×5 cm 3 ) and aluminum (5×5×5 cm 3 ) to represent the inhomogeneities. Scatter factor was defined according to the NCRP-151 recommendations and was calculated for angles of 3° to 120° with respect to the beam’s central axis. A virtual radiation source, with energy sampled from a histogram representing 6 MV FFF beam, was used for irradiation with a field size of 15×15 cm 2 and SSD of 100 cm. Results: Irradiation through the inhomogeneity affects the patient scattered dose. For high Z material inhomogeneities the scattered dose is reduced due to significant attenuation of the primary radiation. On the other hand if the inhomogeneity is a low Z material such as lung the scattered dose is higher by a maximum of 26%. The average increase in scatter factors for the lung phantom was 17% for angles between 3° and 63° compared to the homogeneous water phantom. Conclusions: In IMRT type treatments delivered through low density patient inhomogeneities (lung) the scattered dose increases significantly. Considering a large proportion of patients receiving radiation therapy for lung cancers the increase in the scattered dose should be incorporated in the shielding calculations for the secondary barriers.

  16. Planner concepts in IMRT planning

    International Nuclear Information System (INIS)

    Sahoo, Suvendu Kr.; Rath, A.K.; Patnaik, S.; Mishra, S.K.

    2008-01-01

    IMRT is the most sophisticated, innovative, three- dimensional conformal radiation treatment that delivers highly focused radiation with minimal impact to surrounding normal tissue. As it is a computer control technique, the planar should have adequate knowledge to execute the plan in proper way other wise it is very difficult to get the optimal plan. In this article we want to high light, planner should have the basic concepts before starting the IMRT planning

  17. Evaluation of the radiobiological gamma index with motion interplay in tangential IMRT breast treatment

    Science.gov (United States)

    Sumida, Iori; Yamaguchi, Hajime; Das, Indra J.; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yamada, Yuji; Tamari, Kiesuke; Suzuki, Osamu; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2016-01-01

    The purpose of this study was to evaluate the impact of the motion interplay effect in early-stage left-sided breast cancer intensity-modulated radiation therapy (IMRT), incorporating the radiobiological gamma index (RGI). The IMRT dosimetry for various breathing amplitudes and cycles was investigated in 10 patients. The predicted dose was calculated using the convolution of segmented measured doses. The physical gamma index (PGI) of the planning target volume (PTV) and the organs at risk (OAR) was calculated by comparing the original with the predicted dose distributions. The RGI was calculated from the PGI using the tumor control probability (TCP) and the normal tissue complication probability (NTCP). The predicted mean dose and the generalized equivalent uniform dose (gEUD) to the target with various breathing amplitudes were lower than the original dose (P < 0.01). The predicted mean dose and gEUD to the OARs with motion were higher than for the original dose to the OARs (P < 0.01). However, the predicted data did not differ significantly between the various breathing cycles for either the PTV or the OARs. The mean RGI gamma passing rate for the PTV was higher than that for the PGI (P < 0.01), and for OARs, the RGI values were higher than those for the PGI (P < 0.01). The gamma passing rates of the RGI for the target and the OARs other than the contralateral lung differed significantly from those of the PGI under organ motion. Provided an NTCP value <0.05 is considered acceptable, it may be possible, by taking breathing motion into consideration, to escalate the dose to achieve the PTV coverage without compromising the TCP. PMID:27534793

  18. Incorporating organ movements in IMRT treatment planning for prostate cancer: Minimizing uncertainties in the inverse planning process

    International Nuclear Information System (INIS)

    Unkelbach, Jan; Oelfke, Uwe

    2005-01-01

    We investigate an off-line strategy to incorporate inter fraction organ movements in IMRT treatment planning. Nowadays, imaging modalities located in the treatment room allow for several CT scans of a patient during the course of treatment. These multiple CT scans can be used to estimate a probability distribution of possible patient geometries. This probability distribution can subsequently be used to calculate the expectation value of the delivered dose distribution. In order to incorporate organ movements into the treatment planning process, it was suggested that inverse planning could be based on that probability distribution of patient geometries instead of a single snapshot. However, it was shown that a straightforward optimization of the expectation value of the dose may be insufficient since the expected dose distribution is related to several uncertainties: first, this probability distribution has to be estimated from only a few images. And second, the distribution is only sparsely sampled over the treatment course due to a finite number of fractions. In order to obtain a robust treatment plan these uncertainties should be considered and minimized in the inverse planning process. In the current paper, we calculate a 3D variance distribution in addition to the expectation value of the dose distribution which are simultaniously optimized. The variance is used as a surrogate to quantify the associated risks of a treatment plan. The feasibility of this approach is demonstrated for clinical data of prostate patients. Different scenarios of dose expectation values and corresponding variances are discussed

  19. A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

    International Nuclear Information System (INIS)

    Saenz, Daniel L.; Paliwal, Bhudatt R.; Bayouth, John E.

    2014-01-01

    ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 ( 60 Co) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI), conformity index (CI), and volume receiving 60 Co ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system. (author)

  20. A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans.

    Science.gov (United States)

    Saenz, Daniel L; Paliwal, Bhudatt R; Bayouth, John E

    2014-04-01

    ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI), conformity index (CI), and volume receiving ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system.

  1. A quality and efficiency analysis of the IMFASTTM segmentation algorithm in head and neck 'step and shoot' IMRT treatments

    International Nuclear Information System (INIS)

    Potter, Larry D.; Chang, Sha X.; Cullip, Timothy J.; Siochi, Alfredo C.

    2002-01-01

    The performance of segmentation algorithms used in IMFAST for 'step and shoot' IMRT treatment delivery is evaluated for three head and neck clinical treatments of different optimization objectives. The segmentation uses the intensity maps generated by the in-house TPS PLANUNC using the index-dose minimization algorithm. The dose optimization objectives include PTV dose uniformity and dose volume histogram-specified critical structure sparing. The optimized continuous intensity maps were truncated into five and ten intensity levels and exported to IMFAST for MLC segments optimization. The MLC segments were imported back to PLUNC for dose optimization quality calculation. The five basic segmentation algorithms included in IMFAST were evaluated alone and in combination with either tongue and groove/match line correction or fluence correction or both. Two criteria were used in the evaluation: treatment efficiency represented by the total number of MLC segments and optimization quality represented by a clinically relevant optimization quality factor. We found that the treatment efficiency depends first on the number of intensity levels used in the intensity map and second the segmentation technique used. The standard optimal segmentation with fluence correction is a consistent good performer for all treatment plans studied. All segmentation techniques evaluated produced treatments with similar dose optimization quality values, especially when ten-level intensity maps are used

  2. Is the dose distribution distorted in IMRT and RapidArc treatment when patient plans are swapped across beam‐matched machines?

    Science.gov (United States)

    Radha, Chandrasekaran Anu; Subramani, Vendhan; Gunasekaran, Madhan Kumar

    2016-01-01

    The purpose of this study is to evaluate the degree of dose distribution distortion in advanced treatments like IMRT and RapidArc when patient plans are swapped across dosimetrically equivalent so‐called “beam‐matched” machines. For this purpose the entire work is divided into two stages. At forefront stage all basic beam properties of 6 MV X‐rays like PDD, profiles, output factors, TPR20/10 and MLC transmission of two beam‐matched machines — Varian Clinac iX and Varian 600 C/D Unique — are compared and evaluated for differences. At second stage 40 IMRT and RapidArc patient plans from the pool of head and neck (H&N) and pelvis sites are selected for the study. The plans are swapped across the machines for dose recalculation and the DVHs of target and critical organs are evaluated for dose differences. Following this, the accuracy of the beam‐matching at the TPS level for treatments like IMRT and RapidArc are compared. On PDD, profile (central 80%) and output factor comparison between the two machines, a maximum percentage disagreement value of −2.39%,−2.0% and −2.78%, respectively, has been observed. The maximum dose difference observed at volumes in IMRT and RapidArc treatments for H&N dose prescription of 69.3 Gy/33 fractions is 0.88 Gy and 0.82 Gy, respectively. Similarly, for pelvis, with a dose prescription of 50 Gy/25 fractions, a maximum dose difference of 0.55 Gy and 0.53 Gy is observed at volumes in IMRT and RapidArc treatments, respectively. Overall results of the swapped plans between two machines' 6 MV X‐rays are well within the limits of accepted clinical tolerance. PACS number(s): 87.56.bd PMID:27685106

  3. Primary intraosseous meningiomas

    International Nuclear Information System (INIS)

    Arana, E.; Diaz, C.; Latorre, F.F.; Menor, F.; Revert, A.; Beltran, A.; Navarro, M.

    1996-01-01

    Purpose: A retrospective study was performed to evaluate the clinical, radiological and histological findings of 14 intraosseous meningiomas. Material and Methods: 14 histologically proved intraosseous meningiomas were studied with plain skull film and CT. Pathological records were reviewed. Results: We found 9 calvarial cases and 5 spheno-orbital ones. The most common symptom in the calvarial cases was a lump in the scalp, and in the spheno-orbital lesions it was exophtalmos. Hyperostosis was present in all 5 spheno-orbital cases and in 3 out of the 9 calvarial ones; in the other 6 cases it had a mixed pattern. Enhanced dura was present in 3 calvarial cases and in 2 sphenoidal ones. Dura was involved in 5 cases: 2 with inflammatory changes, 2 with a minimal intradural tumour and one with a subdural tumour. Conclusion: CT better detected both the bony reaction and the intraosseous extension of the tumour. The dural changes were not specific of tumoural involvement. The differential diagnosis comprises: fibrous dysplasia, osteomas, blastic metastasis and mainly meningioma en plaque (MEP). Comparing our findings with other series, we noticed that in some cases the term MEP was used for similar cases. As the name MEP is merely descriptive and both entities share a larger number of similarities than differences, we believe that a differentiation between hyperostotic en plaque meningioma and intraosseous meningioma can hardly be made. (orig.)

  4. SU-F-T-351: Establishing a Workflow for IMRT Pre-Treatment Reviews for NRG-GY006 Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, T [Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); Li, N; Moore, K; Mell, L [University of California, San Diego, San Diego, CA (United States); Curry, K [MIM Software, Inc., Clevealand, OH (United States); Leath, C [University of Alabama at Birmingham, Birmingham, AL (United States); Kunos, C [Northeastern Ohio University College, Clevealand, OH (United States); Xiao, Y [University of Pennsylvania, Philadelphia, PA (United States)

    2016-06-15

    Purpose: To establish a workflow for NRG-GY006 IMRT pre-treatment reviews, incorporating advanced radiotherapy technologies being evaluated as part of the clinical trial. Methods: Pre-Treatment reviews are required for every IMRT case as part of NRG-GY006 (a randomized phase II trial of radiation therapy and cisplatin alone or in combination with intravenous triapine in women with newly diagnosed bulky stage I B2, stage II, IIIB, or IVA cancer of the uterine cervix or stage II-IVA vaginal cancer. The pretreatment review process includes structures review and generating an active bone marrow(ABM)- to be used as an avoidance structure during IMRT optimization- and evaluating initial IMRT plan quality using knowledgeengineering based planning (KBP). Institutions will initially submit their simulation CT scan, structures file and PET/CT to IROC QA center for generating ABM. The ABM will be returned to the institution for use in planning. Institutions will then submit an initial IMRT plan for review and will receive information back following implementation of a KBP algorithm, for use in re-optimization, before submitting the final IMRT used for treatment. Results: ABM structure is generated using MIM vista software (Version 6.5, MIM corporation, Inc.). Here, the planning CT and the diagnostic PET/CT are fused and a sub threshold structure is auto segmented above the mean value of the SUV of the bone marrow. The generated ABM were compared with those generated with other software system (e.g. Velocity, Varian) and Dice coefficient (reflects the overlap of structures) ranged between 80 – 90% was achieved. A KBP model was built in Varian Eclipse TPS using the RapidPlan KBP software to perform plan quality assurance. Conclusion: The workflow for IMRT pretreatment reviews has been established. It represents a major improvement of NRG Oncology clinical trial quality assurance and incorporates the latest radiotherapy technologies as part of NCI clinical trials. This project

  5. SU-F-T-351: Establishing a Workflow for IMRT Pre-Treatment Reviews for NRG-GY006 Clinical Trial

    International Nuclear Information System (INIS)

    Giaddui, T; Li, N; Moore, K; Mell, L; Curry, K; Leath, C; Kunos, C; Xiao, Y

    2016-01-01

    Purpose: To establish a workflow for NRG-GY006 IMRT pre-treatment reviews, incorporating advanced radiotherapy technologies being evaluated as part of the clinical trial. Methods: Pre-Treatment reviews are required for every IMRT case as part of NRG-GY006 (a randomized phase II trial of radiation therapy and cisplatin alone or in combination with intravenous triapine in women with newly diagnosed bulky stage I B2, stage II, IIIB, or IVA cancer of the uterine cervix or stage II-IVA vaginal cancer. The pretreatment review process includes structures review and generating an active bone marrow(ABM)- to be used as an avoidance structure during IMRT optimization- and evaluating initial IMRT plan quality using knowledgeengineering based planning (KBP). Institutions will initially submit their simulation CT scan, structures file and PET/CT to IROC QA center for generating ABM. The ABM will be returned to the institution for use in planning. Institutions will then submit an initial IMRT plan for review and will receive information back following implementation of a KBP algorithm, for use in re-optimization, before submitting the final IMRT used for treatment. Results: ABM structure is generated using MIM vista software (Version 6.5, MIM corporation, Inc.). Here, the planning CT and the diagnostic PET/CT are fused and a sub threshold structure is auto segmented above the mean value of the SUV of the bone marrow. The generated ABM were compared with those generated with other software system (e.g. Velocity, Varian) and Dice coefficient (reflects the overlap of structures) ranged between 80 – 90% was achieved. A KBP model was built in Varian Eclipse TPS using the RapidPlan KBP software to perform plan quality assurance. Conclusion: The workflow for IMRT pretreatment reviews has been established. It represents a major improvement of NRG Oncology clinical trial quality assurance and incorporates the latest radiotherapy technologies as part of NCI clinical trials. This project

  6. Planning issues for IMRT

    International Nuclear Information System (INIS)

    Hoban, P.; Schneider, M.; Smee, R.

    2001-01-01

    Full text: Despite the 'inverse planning' stage of an intensity modulated radiotherapy (IMRT) treatment there remains a large number of variables that can, and must, be set manually. These variables can significantly affect the quality of the dose distribution arrived at by the optimisation. Clinical IMRT planning with the Radionics XPlan system for micro-multileaf collimator (MMLC) delivery has allowed for important lessons to be learned regarding the best beam and organ configurations prior to optimisation of beamlet weights. Important user-definable variables are beam directions, organ parameters (dose goals/penalties), and the margin (if any) around the planning target volume (PTV) used to aid coverage. Conventional stereotactic radiotherapy (SRT) treatments typically involve non-coplanar beams since there is often an advantage in terms of cranial organ at risk (OAR) sparing. IMRT can also benefit from such a configuration. The balance between target coverage and OAR sparing is largely controlled by user-defined goal doses and penalties. Once optimisation has been performed, intensity maps can be discretised into a selected number of levels. Less levels means less field segments and thus a shorter treatment time. Although IMRT beams attempt to spare structures which are in the 'beam's eye view' (BEV) of the target volume, sparing is greater if beams which minimise the involvement of OARs in their view are used. It has been found that the use of a margin is an effective way to ensure adequate PTV coverage. Alternatively the PTV penalties can be made larger. The best result is often obtained by the use of a 3-4 mm margin, whose penalty for underdosage is somewhat less than that for the PTV. Discretising the intensity maps to 4 or 5 levels is typically a good balance between shortening treatment time and not overly degrading the dose distribution. Beam configuration is still an important step in IMRT planning, even though optimisation of intensity maps is

  7. A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans

    Directory of Open Access Journals (Sweden)

    Daniel L Saenz

    2014-01-01

    Full Text Available ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60 with 0.35 Tesla magnetic resonance imaging (MRI allows for magnetic resonance (MR-guided intensity-modulated radiation therapy (IMRT delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI, conformity index (CI, and volume receiving <20% of prescription dose (DRx were calculated to assess the plans. The 95% confidence intervals were recorded for all measurements and presented with the associated bars in graphs. The homogeneity index (D5/D95 had a 1-5% inhomogeneity increase for head and neck, 3-8% for lung, and 4-16% for prostate. CI revealed a modest conformity increase for lung. The volume receiving 20% of the prescription dose increased 2-8% for head and neck and up to 4% for lung and prostate. Overall, for head and neck Co-60 ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system.

  8. High incidence of meningioma among Hiroshima atomic bomb survivors

    International Nuclear Information System (INIS)

    Shintani, Takahiro; Hayakawa, Norihiko; Hoshi, Masaharu

    1999-01-01

    Since the atomic bomb explosions in Hiroshima and Nagasaki, high incidences of leukemia, thyroid cancer and other tumors have been reported as atomic bomb-induced tumors. We investigated the incidence of meningioma among Hiroshima atomic bomb survivors. Sixty-eight patients surgically treated for meningioma who had been within 2.0 km of the hypocenter of the explosion were identified. Six hundred and seven non-exposed patients with meningioma were also studied. Treatment dates were from 1975 to 1992. The incidences of meningioma among 68 subjects within 2.0 km and 607 non-exposed patients were 8.7 and 3.0 cases per 10 5 persons per year, respectively. The incidences of meningioma among the survivors of Hiroshima in 5-year intervals since 1975 were 5.3, 7.4, 10.1, and 14.9, respectively. The incidences of meningioma classified by distances from the hypocenter of 1.5-2.0 km, 1.0-1.5 km and less than 1.0 km were 6.3, 7.6 and 20.0, respectively. The incidences of meningioma classified by doses to the brain of 0-0.099 Sv, 0.1-0.99 Sv and more than 1.0 Sv were 7.7, 9.2 and 18.2, respectively. The incidence of meningioma among Hiroshima atomic bomb survivors has increased since 1975. There was a significant correlation between the incidence and the dose of radiation to the brain. The present findings strongly suggest that meningioma is one of the tumors induced by atomic bombing in Hiroshima. (author)

  9. Intraventricular trigonal meningioma: Neuronavigation? No, thanks!

    Science.gov (United States)

    Silva, Danilo O A; Matis, Georgios K; Costa, Leonardo F; Kitamura, Matheus A P; Birbilis, Theodossios A; Azevedo Filho, Hildo R C

    2011-01-01

    Most of the time meningiomas are benign brain tumors and surgical removal ensures cure in the vast majority of the cases. Thus, whenever possible, complete surgical resection should be the goal of the treatment. This is a report of our surgical technique for the operative resection of a trigonal meningioma in a resource-limited setting. The necessity of accurate and deep knowledge of the regional anatomy is outlined. A 44-year-old male presented to our outpatient clinic complaining of cephalalgia increasing in frequency and intensity over the last month. His neurological exam was normal, yet a brain computed tomography scan revealed a lesion in the right trigone of the ventricular system. The diagnosis of possible meningioma was set. After thoroughly informing the patient, tumor resection was decided. An intraparietal sulcus approach was favored without the use of any modern technological aids such as intraoperative magnetic resonance imaging or neuronavigation. The postoperative course was uneventful and a postoperative computed tomography scan demonstrated the complete resection of the tumor. The patient was discharged two days later with no neurological deficits. In a two-year-follow-up he remains recurrence-free. In the current cost-effective era it is still possible to safely remove an intraventricular trigonal meningioma without the convenience of neuronavigation. Since the best neuronavigator is the profound neuroanatomical knowledge, no technological advancement could replace a well-educated and trained neurosurgeon.

  10. Primary optic nerve sheath meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Jeremic, Branislav [International Atomic Energy Agency, Vienna (Austria); Pitz, Susanne (eds.) [University Eye Hospital, Mainz (Germany)

    2008-07-01

    Optic nerve sheath meningioma (ONSM) is a rare tumour. Cases are usually separated into primary ONSM, which arises either intraorbitally or, less commonly, intracanalicularly, and secondary ONSM, which arises intracranially and subsequently invades the optic canal and orbit. This is the first book to cover all important aspects of the diagnosis and treatment of primary ONSM. After a general introduction, individual chapters discuss the clinical presentation, clinical examination and diagnosis, imaging, and histology. Treatment options are then addressed in detail, with special emphasis on external beam radiation therapy, and in particular stereotactic fractionated radiation therapy. The latter has recently produced consistently good results and is now considered the emerging treatment of choice for the vast majority of patients with primary ONSM. This well-illustrated book will prove invaluable to all practitioners who encounter primary ONSM in their clinical work. (orig.)

  11. SU-F-T-395: Evaluation of Best Dosimetry Achievable with VMAT and IMRT Treatment Techniques Targeting Borderline Resectable Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harpool, K; Schnell, E; Herman, T; Ahmad, S; De La Fuente Herman, T [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To determine from retrospective study the most appropriate technique for targeting small borderline operable pancreatic cancer surrounding blood vessels by evaluating the dosimetry and normal tissue sparing achievable using Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT). Methods: Treatment plans from ten patients who have undergone treatment with a prescribed dose of 4950 cGy, at 275 cGy per fraction, were analyzed. All plans were replanned using Eclipse TPS (Varian Medical Systems, Palo Alto, CA) with complementary VMAT or IMRT techniques to obtain paired data sets for comparison. The coverage to at least 95% of the planned target volume (PTV) was normalized to receive 100% of the prescription dose. The normal tissue constraints followed the quantitative analysis of normal tissue effects in the clinic (QUANTEC) guidelines and the organs at risks (OARs) were liver, kidneys, spinal cord and bowel. The plan evaluation was based on conformity index (CI), homogeneity index (HI), uniformity index (UI), DVH parameters, and student’s-t statistics (2 tails). Results: The VMAT technique delivered less maximum dose to the right kidney, left kidney, total kidney, liver, spinal cord, and bowel by 9.3%, 5.9%, 6.7%, 3.9%, 15.1%, 3.9%, and 4.3%, respectively. The averaged V15 for the total kidney was 10.21% for IMRT and 7.29% for VMAT. The averaged V20 for the bowel was 19.89% for IMRT and 14.06% for VMAT. On average, the CI for IMRT was 1.20 and 1.16 for VMAT (p = 0.20). The HI was 0.08 for both techniques (p = 0.91) and UI was 1.05 and 1.06 for IMRT and VMAT respectively (p = 0.59). Conclusion: Both techniques achieve adequate PTV coverage. Although VMAT techniques show better normal tissue sparing from excessive dose, no significant differences were observed. Slight discrepancies may rise from different versions of calculation algorithms.

  12. A treatment planning study comparing whole breast radiation therapy against conformal, IMRT and tomotherapy for accelerated partial breast irradiation

    International Nuclear Information System (INIS)

    Oliver, Mike; Chen, Jeff; Wong, Eugene; Van Dyk, Jake; Perera, Francisco

    2007-01-01

    Purpose and background: Conventional early breast cancer treatment consists of a lumpectomy followed by whole breast radiation therapy. Accelerated partial breast irradiation (APBI) is an investigational approach to post-lumpectomy radiation for early breast cancer. The purpose of this study is to compare four external beam APBI techniques, including tomotherapy, with conventional whole breast irradiation for their radiation conformity index, dose homogeneity index, and dose to organs at risk. Methods and materials: Small-field tangents, three-dimensional conformal radiation therapy, intensity-modulated radiation therapy and helical tomotherapy were compared for each of 15 patients (7 right, 8 left). One radiation conformity and two dose homogeneity indices were used to evaluate the dose to the target. The mean dose to organs at risk was also evaluated. Results: All proposed APBI techniques improved the conformity index significantly over whole breast tangents while maintaining dose homogeneity and without a significant increase in dose to organs at risk. Conclusion: The four-field IMRT plan produced the best dosimetric results; however this technique would require appropriate respiratory motion management. An alternative would be to use a four-field conformal technique that is less sensitive to the effects of respiratory motion

  13. Multi-institutional evaluation of end-to-end protocol for IMRT/VMAT treatment chains utilizing conventional linacs.

    Science.gov (United States)

    Loughery, Brian; Knill, Cory; Silverstein, Evan; Zakjevskii, Viatcheslav; Masi, Kathryn; Covington, Elizabeth; Snyder, Karen; Song, Kwang; Snyder, Michael

    2018-03-20

    We conducted a multi-institutional assessment of a recently developed end-to-end monthly quality assurance (QA) protocol for external beam radiation therapy treatment chains. This protocol validates the entire treatment chain against a baseline to detect the presence of complex errors not easily found in standard component-based QA methods. Participating physicists from 3 institutions ran the end-to-end protocol on treatment chains that include Imaging and Radiation Oncology Core (IROC)-credentialed linacs. Results were analyzed in the form of American Association of Physicists in Medicine (AAPM) Task Group (TG)-119 so that they may be referenced by future test participants. Optically stimulated luminescent dosimeter (OSLD), EBT3 radiochromic film, and A1SL ion chamber readings were accumulated across 10 test runs. Confidence limits were calculated to determine where 95% of measurements should fall. From calculated confidence limits, 95% of measurements should be within 5% error for OSLDs, 4% error for ionization chambers, and 4% error for (96% relative gamma pass rate) radiochromic film at 3% agreement/3 mm distance to agreement. Data were separated by institution, model of linac, and treatment protocol (intensity-modulated radiation therapy [IMRT] vs volumetric modulated arc therapy [VMAT]). A total of 97% of OSLDs, 98% of ion chambers, and 93% of films were within the confidence limits; measurements were found outside these limits by a maximum of 4%, consistent despite institutional differences in OSLD reading equipment and radiochromic film calibration techniques. Results from this test may be used by clinics for data comparison. Areas of improvement were identified in the end-to-end protocol that can be implemented in an updated version. The consistency of our data demonstrates the reproducibility and ease-of-use of such tests and suggests a potential role for their use in broad end-to-end QA initiatives. Copyright © 2018 American Association of Medical

  14. The use of IMRT in Germany

    International Nuclear Information System (INIS)

    Frenzel, Thorsten; Kruell, Andreas

    2015-01-01

    Intensity modulated radiotherapy (IMRT) is frequently used, but there are no data about current frequency regarding specific tumor sites and equipment used for quality assurance (QA). An online survey about IMRT was executed from April to October 2014 by the collaborative IMRT working group (AK IMRT) of the German Association of Medical Physicists (DGMP). A total of 23 German institutions took part in the survey. Most reports came from users working with Elekta, Varian, and Siemens treatment machines, but also from TomoTherapy and BrainLab. Most frequent IMRT technology was volumetric modulated arc therapy (58.37 %: VMAT/''rapid arc''), followed by step-and-shoot IMRT (14.66 %), dynamic MLC (dMLC: 14.53 %), TomoTherapy (9.25 %), and 3.2 % other techniques. Different commercial hard- and software solutions are available for QA, whereas many institutes still develop their own phantoms. Data of 26,779 patients were included in the survey; 44 % were treated using IMRT techniques. IMRT was most frequently used for anal cancer, (whole) craniospinal irradiation, head and neck cancer, prostate cancer, other tumors in the pelvic region, gynecological tumors (except for breast cancer), and brain tumors. An estimated 10 % of all patients treated in 2014 with radiation in Germany were included in the survey. It is representative for the members of the AK IMRT. IMRT may be on the way to replace other treatment techniques. However, many scientific questions are still open. In particular, it is unclear when the IMRT technique should not be used. (orig.) [de

  15. Long-Term Results of Gamma Knife Radiosurgery for Intracranial Meningioma.

    Science.gov (United States)

    Jang, Chang Ki; Jung, Hyun Ho; Chang, Jong Hee; Chang, Jin Woo; Park, Yong Gou; Chang, Won Seok

    2015-10-01

    The predominant treatment modality for meningioma is surgical resection. However, gamma knife radiosurgery is also an important treatment modality for meningioma that is small or cannot be completely removed because of its location. In this study, we evaluated the effectiveness and long-term results of radiosurgical treatment for meningioma in our institution. We studied 628 patients (130 men and 498 women) who underwent gamma knife radiosurgery for intracranial meningioma, which is radiologically diagnosed, from Jan 2008 to Nov 2012. We included patients with single lesion meningioma, and followed up after 6 months with imaging, and then at 24 months with a clinical examination. Patients with high-grade meningioma or multiple meningiomas were excluded. We analyzed each of the factors associated with progression free survival. The median patient's age was 56.8 years. Maximal dosage was 27.8 Gy and marginal dosage was 13.9 Gy. The overall tumor control rate was 95%. Twenty-eight patients (4.4%) showed evidence of tumor recurrence. Ninety-eight patients (15%) developed peritumoral edema (PTE) after gamma-knife surgery; two of them (2%) underwent surgical resections due to PTE. Nine patients had craniotomy and tumor removal after gamma knife surgery. Gamma knife surgery for intracranial meningioma has proven to be a safe and effective treatment tool with successful long-term outcomes. Gamma knife radiosurgery can be especially effective in cases of remnant meningioma after surgical resection or where PTE is not present.

  16. A Review of Stereotactic Radiosurgery Practice in the Management of Skull Base Meningiomas

    OpenAIRE

    Vera, Elena; Iorgulescu, J. Bryan; Raper, Daniel M.S.; Madhavan, Karthik; Lally, Brian E.; Morcos, Jacques; Elhammady, Samy; Sherman, Jonathan; Komotar, Ricardo J.

    2014-01-01

    Gross total resection of skull base meningiomas poses a surgical challenge due to their proximity to neurovascular structures. Once the gold standard therapy for skull base meningiomas, microsurgery has been gradually replaced by or used in combination with stereotactic radiosurgery (SRS). This review surveys the safety and efficacy of SRS in the treatment of cranial base meningiomas including 36 articles from 1991 to 2010. SRS produces excellent tumor control with low morbidity rates compare...

  17. Malignant Subdural Hematoma Associated with High-Grade Meningioma

    Science.gov (United States)

    Teramoto, Shinichiro; Tsunoda, Akira; Kawamura, Kaito; Sugiyama, Natsuki; Saito, Rikizo; Maruki, Chikashi

    2018-01-01

    A 70-year-old man, who had previously undergone surgical resection of left parasagittal meningioma involving the middle third of the superior sagittal sinus (SSS) two times, presented with recurrence of the tumor. We performed removal of the tumor combined with SSS resection as Simpson grade II. After tumor removal, since a left dominant bilateral chronic subdural hematoma (CSDH) appeared, it was treated by burr hole surgery. However, because the CSDH rapidly and repeatedly recurred and eventually changed to acute subdural hematoma, elimination of the hematoma with craniotomy was accomplished. The patient unfortunately died of worsening of general condition despite aggressive treatment. Histopathology of brain autopsy showed invasion of anaplastic meningioma cells spreading to the whole outer membrane of the subdural hematoma. Subdural hematoma is less commonly associated with meningioma. Our case indicates the possibility that subdural hematoma associated with meningioma is formed by a different mechanism from those reported previously. PMID:29896565

  18. A project proposal for the implementation of Intensity Modulated Radiation Therapy (IMRT) for treatment of tumors of the central nervous system (CNS)

    International Nuclear Information System (INIS)

    Alert Silva, Jose; Chon Rivas, Ivon; Ascension Ibarra, Yudy; Yanez Lopez, Yaima; Rodriguez Zayas, Michel; Diaz Moreno, Rogelio

    2009-01-01

    Radiotherapy, together with the surgery, one of the essential therapeutic tools in the treatment of CNS tumors. The use of radiation, can be severe sequelae affecting quality of life of the patient, organs at risk receiving high dose and advanced technique of IMRT treatment planning and allows treatments shaped fields, especially when the target of radiation is irregular, with fewer side effects by limiting the dose in the tumor tissues and organs at risk and to allow us to increase the doses in the tumor .. So we decided to develop a protocol for the implementation of IMRT, taking into account that we have the appropriate equipment, trained staff to develop this technique. The main objective of this proposal is to allow us to establish the parameters necessary to perform IMRT, and then escalate the dose of radiation to the tumor, with reduced toxicity to healthy tissues. Inclusion criteria. It included 6 patients with histological diagnosis of CNS tumors, specifically astrocytomas grade II, III and IV, glioblastoma multiforme, where radiation is the main treatment, or associated with surgery. It excludes patients who have previously received radiation therapy or are unable to receive treatment without having movements that do not suffer another debilitating disease and to sign informed consent. Be held position and will be used as masks thermo deformed stun, then planning CT performed in all cases. Be designed later volumes (GTV, CTV and PTV, and OR, as established by the ICRU reports 52 and 60, the IAEA), will define the dose, and restrictions on healthy tissue technique is defined treatment according proposed objectives in the planning system. Once approved, is made conventional simulation, verification of the treatment plan on your computer with web plates and implementation of treatment in 1220 of INOR LINAC. Be made patient-specific quality controls and verification of DRR plan once a week for each patient treated. Monitoring will be conducted weekly during

  19. SU-E-J-70: Feasibility Study of Dynamic Arc and IMRT Treatment Plans Utilizing Vero Treatment Unit and IPlan Planning Computer for SRS/FSRT Brain Cancer Patients

    International Nuclear Information System (INIS)

    Huh, S; Lee, S; Dagan, R; Malyapa, R; Mendenhall, N; Mendenhall, W; Ho, M; Hough, D; Yam, M; Li, Z

    2014-01-01

    Purpose: To investigate the feasibility of utilizing Dynamic Arc (DA) and IMRT with 5mm MLC leaf of VERO treatment unit for SRS/FSRT brain cancer patients with non-invasive stereotactic treatments. The DA and IMRT plans using the VERO unit (BrainLab Inc, USA) are compared with cone-based planning and proton plans to evaluate their dosimetric advantages. Methods: The Vero treatment has unique features like no rotational or translational movements of the table during treatments, Dynamic Arc/IMRT, tracking of IR markers, limitation of Ring rotation. Accuracies of the image fusions using CBCT, orthogonal x-rays, and CT are evaluated less than ∼ 0.7mm with a custom-made target phantom with 18 hidden targets. 1mm margin is given to GTV to determine PTV for planning constraints considering all the uncertainties of planning computer and mechanical uncertainties of the treatment unit. Also, double-scattering proton plans with 6F to 9F beams and typical clinical parameters, multiple isocenter plans with 6 to 21 isocenters, and DA/IMRT plans are evaluated to investigate the dosimetric advantages of the DA/IMRT for complex shape of targets. Results: 3 Groups of the patients are divided: (1) Group A (complex target shape), CI's are same for IMRT, and DGI of the proton plan are better by 9.5% than that of the IMRT, (2) Group B, CI of the DA plans (1.91+/−0.4) are better than cone-based plan, while DGI of the DA plan is 4.60+/−1.1 is better than cone-based plan (5.32+/−1.4), (3) Group C (small spherical targets), CI of the DA and cone-based plans are almost the same. Conclusion: For small spherical targets, cone-based plans are superior to other 2 plans: DS proton and DA plans. For complex or irregular plans, dynamic and IMRT plans are comparable to cone-based and proton plans for complex targets

  20. Psychopathological manifestations of multiple meningiomas in the right hemisphere

    Directory of Open Access Journals (Sweden)

    A. A. Lukshina

    2015-01-01

    Full Text Available The paper gives the data available in the literature on meningiomas and their psychopathological manifestations that occupy a central position in the clinical picture in almost every 5 patients with these tumors. The authors provide a clinical and psychopathological analysis of a female patient with multiple meningiomas in the right hemisphere: a giant meningioma in the posterior third of the falx, a large meningioma in the temporal region, and three small meningiomas in the frontal and parietal regions. The disease started as headache; however, psychopathological symptoms remained missed by physicians, such as emotional lability; personality changes leading to family dissension; lower criticism; spatial orientation problems; hypomnesia; left-sided visual inattention,occurred in parallel. Surgical treatment was performed by stages: the two largest meningiomas were removed at an 11-day interval, which presented a means of observing psychopathological changes after each operation. It is concluded that greater attention should be given to the psychopathological manifestations of the disease, which is important to make a primary diagnosis and to define further treatment policy.

  1. MRI of meningioma

    International Nuclear Information System (INIS)

    Yamamoto, Yoshio; Hiraki, Yoshio; Kaji, Mitumasa

    1988-01-01

    MRI has gained a prominent position in the diagnosis of brain tumors. We examined 30 cases of meningiomas and distinguished their subtype according to the criteria of Rubinic histology. We discussed the MRI findings and compared then with X-CT findings so to their intensity, delination of tumors, whether accompanied by peripheral edema, and T 1 values. MRI delinated the tumors as well as CE-CT. No remarkable difference was found between the subtypes. (author)

  2. Software for simulating IMRT protocol

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Thelma C.F.; Campos, Tarcisio P.R. de, E-mail: tcff@ufmg.b, E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2009-07-01

    The Intensity Modulated Radiation Therapy - IMRT is an advanced technique to cancer treatment widely used on oncology around the world. The present paper describes the SOFT-RT software which is a tool for simulating IMRT protocol. Also, it will be present a cerebral tumor case of studied in which three irradiation windows with distinct orientation were applied. The SOFT-RT collect and export data to MCNP code. This code simulates the photon transport on the voxel model. Later, a out-module from SOFT-RT import the results and express the dose-response superimposing dose and voxel model in a tree-dimensional graphic representation. The present paper address the IMRT software and its function as well a cerebral tumor case of studied is showed. The graphic interface of the SOFT-RT illustrates the example case. (author)

  3. Software for simulating IMRT protocol

    International Nuclear Information System (INIS)

    Fonseca, Thelma C.F.; Campos, Tarcisio P.R. de

    2009-01-01

    The Intensity Modulated Radiation Therapy - IMRT is an advanced technique to cancer treatment widely used on oncology around the world. The present paper describes the SOFT-RT software which is a tool for simulating IMRT protocol. Also, it will be present a cerebral tumor case of studied in which three irradiation windows with distinct orientation were applied. The SOFT-RT collect and export data to MCNP code. This code simulates the photon transport on the voxel model. Later, a out-module from SOFT-RT import the results and express the dose-response superimposing dose and voxel model in a tree-dimensional graphic representation. The present paper address the IMRT software and its function as well a cerebral tumor case of studied is showed. The graphic interface of the SOFT-RT illustrates the example case. (author)

  4. TU-F-CAMPUS-J-04: Setup Uncertainties in the Mediastinum Area for IMRT Treatment of Lymphoma Patients

    Energy Technology Data Exchange (ETDEWEB)

    Aristophanous, M; Court, L [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: Despite daily image guidance setup uncertainties can be high when treating large areas of the body. The aim of this study was to measure local uncertainties inside the PTV for patients receiving IMRT to the mediastinum region. Methods: Eleven lymphoma patients that received radiotherapy (breath-hold) to the mediastinum were included in this study. The treated region could range all the way from the neck to the diaphragm. Each patient had a CT scan with a CT-on-rails system prior to every treatment. The entire PTV region was matched to the planning CT using automatic rigid registration. The PTV was then split into 5 regions: neck, supraclavicular, superior mediastinum, upper heart, lower heart. Additional auto-registrations for each of the 5 local PTV regions were performed. The residual local setup errors were calculated as the difference between the final global PTV position and the individual final local PTV positions for the AP, SI and RL directions. For each patient 4 CT scans were analyzed (1 per week of treatment). Results: The residual mean group error (M) and standard deviation of the inter-patient (or systematic) error (Σ) were lowest in the RL direction of the superior mediastinum (0.0mm and 0.5mm) and highest in the RL direction of the lower heart (3.5mm and 2.9mm). The standard deviation of the inter-fraction (or random) error (σ) was lowest in the RL direction of the superior mediastinum (0.5mm) and highest in the SI direction of the lower heart (3.9mm) The directionality of local uncertainties is important; a superior residual error in the lower heart for example keeps it in the global PTV. Conclusion: There is a complex relationship between breath-holding and positioning uncertainties that needs further investigation. Residual setup uncertainties can be significant even under daily CT image guidance when treating large regions of the body.

  5. SU-E-T-77: A Statistical Approach to Manage Quality for Pre-Treatment Verification in IMRT/VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Jassal, K [Fortis Memorial Research Institute, Gurgaon, Haryana (India); Sarkar, B [AMRI Cancer Centre and GLA university, Mathura, Kolkata, West Bengal (India); Mohanti, B; Roy, S; Ganesh, T [FMRI, Gurgaon, Haryana (India); Munshi, A [Fortis Memorial Research Institute, Gurgon, Haryana (India); Chougule, A [SMS Medical College and Hospital, Jaipur, Rajasthan (India); Sachdev, K [Malaviya National Institute of Technology, Jaipur, Rajasthan (India)

    2015-06-15

    Objective: The study presents the application of a simple concept of statistical process control (SPC) for pre-treatment quality assurance procedure analysis for planar dose measurements performed using 2D-array and a-Si electronic portal imaging device (a-Si EPID). Method: A total of 195 patients of four different anatomical sites: brain (n1=45), head & neck (n2=45), thorax (n3=50) and pelvis (n4=55) were selected for the study. Pre-treatment quality assurance for the clinically acceptable IMRT/VMAT plans was measured with 2D array and a-Si EPID of the accelerator. After the γ-analysis, control charts and the quality index Cpm was evaluated for each cohort. Results: Mean and σ of γ ( 3%/3 mm) were EPID γ %≤1= 99.9% ± 1.15% and array γ %<1 = 99.6% ± 1.06%. Among all plans γ max was consistently lower than for 2D array as compared to a-Si EPID. Fig.1 presents the X-bar control charts for every cohort. Cpm values for a-Si EPID were found to be higher than array, detailed results are presented in table 1. Conclusion: Present study demonstrates the significance of control charts used for quality management purposes in newer radiotherapy clinics. Also, provides a pictorial overview of the clinic performance for the advanced radiotherapy techniques.Higher Cpm values for EPID indicate its higher efficiency than array based measurements.

  6. Craniospinal treatment with IMRT multi-isocentric and image-guided linear accelerator based on Gantry

    International Nuclear Information System (INIS)

    Sanz Beltran, M.; Caballero Perea, B.; Rodriguez Rodriguez, C.; Arminio Diaz, E.; Lopez Fernandez, A.; Gomez Fervienza, J. R.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.; Gomez Fervienza, J. r.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.

    2011-01-01

    The objective is the realization of craniospinal treatment with a linear accelerator equipped with gantry based on MLC, carbon fiber table and Image Guided capability. The great length of treatment (patient l,80m in height) was a great difficulty for want of full length of the longitudinal movement of the table to adequately cover the PTV, plus free metallic screws fastening the head of the table extender preventing further incidents.

  7. Prior surgical intervention and tumor size impact clinical outcome after precision radiotherapy for the treatment of optic nerve sheath meningiomas (ONSM)

    International Nuclear Information System (INIS)

    Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Debus, Jürgen; Combs, Stephanie E

    2011-01-01

    We analyzed our long-term experience with fractionated stereotactic radiotherapy (FSRT) in patients with meningioma of the optic nerve sheath (ONSM). Between January 1991 and January 2010, 40 patients with ONSM were treated using FSRT. Of these, 19 patients received radiotherapy as primary treatment, and 21 patients were treated after surgical resection. The median target volume was 9.2 ml, median total dose was 54 Gy in median single fractions of 1,8 Gy. Local progression-free survival was 100%. Median survival after FSRT was 60 months (range 4-228 months). In all patients overall toleration of FSRT was very good. Acute toxicity was mild. Prior to RT, 29 patients complained about any kind of visual impairment including visual field deficits, diplopia or amaurosis. Prior surgical resection was identified as a negative prognostic factor for visual outcome, whereas patients with larger tumor volumes demonstrated a higher number of patients with improvement of pre-existing visual deficits. Long-term outcome after FSRT for ONSM shows improved vision in patients not treated surgically prior to RT; moreover, the best improvement of visual deficits are observed in patients with larger target volumes. The absence of tumor recurrences supports that FSRT is a strong alternative to surgical resection especially in small tumors without extensive compression of normal tissue structures

  8. Surgery for convexity/parasagittal/falx meningiomas

    International Nuclear Information System (INIS)

    Ochi, Takashi; Saito, Nobuhito

    2013-01-01

    Incidence of the complication related with the surgical treatment of meningiomas in the title was reviewed together with consideration of data about progress observation and stereotactic radiosurgery. MEDLINE papers in English were on line searched with keywords contained in above using PubMed System. For the convexity meningioma, 50-141 cases (mean age, 48-58.9 y) with 1.9-3.6 cm or 146.3 mL of the tumor size or volume were reported in 6 literatures (2006-2011), presenting 0% of surgery related death, 1-5.9% of internal medical or 5.5-37.4% of surgical complication, 0-2% of postoperative hemorrhage, 0-15.4% of neurological and 0-15.4% of prolonged/permanent deficits. For the parasagittal/falx meningioma, 46-108 cases (age, 55-58 y) with 1.9-4 cm tumor were reported in 8 literatures (2004-2011), presenting 0-5.7% death, 2-7.4% medical or 5.4-31% surgical complication, 0-3% hemorrhage, 0-15.4 neurologic and 0-15.4% prolonged deficits. For complications after the radiosurgery of the all 3 meningiomas, 41-832 cases (50-60 y) with tumors of 24.7-28 mm or 4.7-7.4 mL were reported in 8 literatures (2003-2012), presenting the incidence of 6.8-26.8% of radiation-related complications like headache, seizures and paralysis necessary for steroid treatment, and 1.20 or 4.80% of permanent morbidity. For the natural history of incidental meningiomas involving tentorium one, 16-144 cases in 6 literatures (2000-2012) revealed the growth rate/y of 1.9-3.9 mm or 0.54-1.15 mL. The outcome of surgical treatment of the meningiomas, a representative benign tumor, was concluded to be rather good as surgery was generally needed only when the disease became symptomatic due to the tumor growth. (T.T.)

  9. Stereotactic radiotherapy of meningiomas compressing optical pathways

    International Nuclear Information System (INIS)

    Hamm, Klaus-Detlef; Henzel, Martin; Gross, Markus W.; Surber, Gunnar; Kleinert, Gabriele; Engenhart-Cabillic, Rita

    2006-01-01

    Purpose: Microsurgical resection is usually the treatment of choice for meningiomas, especially for those that compress the optical pathways. However, in many cases of skull-base meningiomas a high risk of neurological deficits and recurrences exist in cases where the complete tumor removal was not possible. In such cases (fractionated) stereotactic radiotherapy (SRT) can offer an alternative treatment option. We evaluated the local control rate, symptomatology, and toxicity. Patients and Methods: Between 1997 and 2003, 183 patients with skull-base meningiomas were treated with SRT, among them were 65 patients with meningiomas that compressed optical pathways (64 benign, 1 atypical). Of these 65 cases, 20 were treated with SRT only, 27 were subtotally resected before SRT, and 18 underwent multiple tumor resections before SRT. We investigated the results until 2005, with a median follow-up of 45 months (range, 22-83 months). The tumor volume (TV = gross tumor volume) ranged from 0.61 to 90.20 cc (mean, 18.9 cc). Because of the risk of new visual disturbances, the dose per fraction was either 2 or 1.8 Gy for all patients, to a total dose of 50 to 60 Gy. Results: The overall survival and the progression-free survival rates for 5 years were assessed to 100% in this patient group. To date, no progression for these meningiomas have been observed. Quantitatively, tumor shrinkage of more than 20%, or more than 2 mm in diameter, was proved in 35 of the 65 cases after SRT. In 29 of the 65 patients, at least 1 of the symptoms improved. On application of the Common Toxicity Criteria (CTC), acute toxicity (Grade 3) was seen in 1 case (worsening of conjunctivitis). Another 2 patients developed late toxicity by LENT-SOMA score, 1 x Grade 1 and 1 x Grade 3 (field of vision loss). Conclusion: As a low-risk and effective treatment option for tumor control, SRT with 1.8 to 2.0 Gy per fraction can also be recommended in case of meningiomas that compress optical pathways. An

  10. Primary extradural meningioma arising from the calvarium

    Directory of Open Access Journals (Sweden)

    N Ravi

    2013-06-01

    Full Text Available Meningiomas are the most common intracranial tumours. Meningiomas arising at other locations are termed primary extradural meningiomas (EDM and are rare. Here we report a case of EDM arising from the calvarium – a primary calvarial meningioma (PCM.

  11. Intraparenchymal papillary meningioma of brainstem: case report and literature review

    Directory of Open Access Journals (Sweden)

    Jiang Xiao-Bing

    2012-01-01

    Full Text Available Abstract Both intraparenchymal papillary meningioma and papillary meningioma with cyst formation of brainstem have never been reported. The authors present an extremely rare case of patient with intraparenchymal papillary meningioma of brainstem. A 23-year-old Chinese male presented with a 4-month history of progressive left upper limb and facial nerve palsy. Magnetic resonance imaging revealed a cystic-solid, heterogeneously enhancing mass in pons and right cerebral peduncle with no dural attachment. The tumor was totally removed via subtemporal approach. During surgery, the lesion was found to be completely intraparenchymal. Histological and immunohistochemical examinations were compatible with the diagnosis of papillary meningioma. The lesion recurred nine months after primary surgery, a second surgery followed by radiotherapy was performed. Till to now (nearly 2 years after the treatment, the patient is tumor free survival. Intraparenchymal meningioma of brainstem with cystic formation is very rare, however, it should be considered as a differential diagnosis of a brainstem neoplasm. The present case strongly recommended that postoperative radiotherapy was essential for the patients with papillary meningiomas.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  13. AAA and AXB algorithms for the treatment of nasopharyngeal carcinoma using IMRT and RapidArc techniques.

    Science.gov (United States)

    Kamaleldin, Maha; Elsherbini, Nader A; Elshemey, Wael M

    2017-09-27

    The aim of this study is to evaluate the impact of anisotropic analytical algorithm (AAA) and 2 reporting systems (AXB-D m and AXB-D w ) of Acuros XB algorithm (AXB) on clinical plans of nasopharyngeal patients using intensity-modulated radiotherapy (IMRT) and RapidArc (RA) techniques. Six plans of different algorithm-technique combinations are performed for 10 patients to calculate dose-volume histogram (DVH) physical parameters for planning target volumes (PTVs) and organs at risk (OARs). The number of monitor units (MUs) and calculation time are also determined. Good coverage is reported for all algorithm-technique combination plans without exceeding the tolerance for OARs. Regardless of the algorithm, RA plans persistently reported higher D 2% values for PTV-70. All IMRT plans reported higher number of MUs (especially with AXB) than did RA plans. AAA-IMRT produced the minimum calculation time of all plans. Major differences between the investigated algorithm-technique combinations are reported only for the number of MUs and calculation time parameters. In terms of these 2 parameters, it is recommended to employ AXB in calculating RA plans and AAA in calculating IMRT plans to achieve minimum calculation times at reduced number of MUs. Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  14. Monte Carlo evaluation of the AAA treatment planning algorithm in a heterogeneous multilayer phantom and IMRT clinical treatments for an Elekta SL25 linear accelerator

    International Nuclear Information System (INIS)

    Sterpin, E.; Tomsej, M.; Smedt, B. de; Reynaert, N.; Vynckier, S.

    2007-01-01

    The Anisotropic Analytical Algorithm (AAA) is a new pencil beam convolution/superposition algorithm proposed by Varian for photon dose calculations. The configuration of AAA depends on linear accelerator design and specifications. The purpose of this study was to investigate the accuracy of AAA for an Elekta SL25 linear accelerator for small fields and intensity modulated radiation therapy (IMRT) treatments in inhomogeneous media. The accuracy of AAA was evaluated in two studies. First, AAA was compared both with Monte Carlo (MC) and the measurements in an inhomogeneous phantom simulating lung equivalent tissues and bone ribs. The algorithm was tested under lateral electronic disequilibrium conditions, using small fields (2x2 cm 2 ). Good agreement was generally achieved for depth dose and profiles, with deviations generally below 3% in lung inhomogeneities and below 5% at interfaces. However, the effects of attenuation and scattering close to the bone ribs were not fully taken into account by AAA, and small inhomogeneities may lead to planning errors. Second, AAA and MC were compared for IMRT plans in clinical conditions, i.e., dose calculations in a computed tomography scan of a patient. One ethmoid tumor, one orophaxynx and two lung tumors are presented in this paper. Small differences were found between the dose volume histograms. For instance, a 1.7% difference for the mean planning target volume dose was obtained for the ethmoid case. Since better agreement was achieved for the same plans but in homogeneous conditions, these differences must be attributed to the handling of inhomogeneities by AAA. Therefore, inherent assumptions of the algorithm, principally the assumption of independent depth and lateral directions in the scaling of the kernels, were slightly influencing AAA's validity in inhomogeneities. However, AAA showed a good accuracy overall and a great ability to handle small fields in inhomogeneous media compared to other pencil beam convolution

  15. Application programming in C# environment with recorded user software interactions and its application in autopilot of VMAT/IMRT treatment planning.

    Science.gov (United States)

    Wang, Henry; Xing, Lei

    2016-11-08

    An autopilot scheme of volumetric-modulated arc therapy (VMAT)/intensity-modulated radiation therapy (IMRT) planning with the guidance of prior knowl-edge is established with recorded interactions between a planner and a commercial treatment planning system (TPS). Microsoft (MS) Visual Studio Coded UI is applied to record some common planner-TPS interactions as subroutines. The TPS used in this study is a Windows-based Eclipse system. The interactions of our application program with Eclipse TPS are realized through a series of subrou-tines obtained by prerecording the mouse clicks or keyboard strokes of a planner in operating the TPS. A strategy to autopilot Eclipse VMAT/IMRT plan selection process is developed as a specific example of the proposed "scripting" method. The autopiloted planning is navigated by a decision function constructed with a reference plan that has the same prescription and similar anatomy with the case at hand. The calculation proceeds by alternating between the Eclipse optimization and the outer-loop optimization independent of the Eclipse. In the C# program, the dosimetric characteristics of a reference treatment plan are used to assess and modify the Eclipse planning parameters and to guide the search for a clinically sensible treatment plan. The approach is applied to plan a head and neck (HN) VMAT case and a prostate IMRT case. Our study demonstrated the feasibility of application programming method in C# environment with recorded interactions of planner-TPS. The process mimics a planner's planning process and automatically provides clinically sensible treatment plans that would otherwise require a large amount of manual trial and error of a planner. The proposed technique enables us to harness a commercial TPS by application programming via the use of recorded human computer interactions and provides an effective tool to greatly facilitate the treatment planning process. © 2016 The Authors.

  16. Deliverable navigation for multicriteria IMRT treatment planning by combining shared and individual apertures

    International Nuclear Information System (INIS)

    Fredriksson, Albin; Bokrantz, Rasmus

    2013-01-01

    We consider the problem of deliverable Pareto surface navigation for step-and-shoot intensity-modulated radiation therapy. This problem amounts to calculation of a collection of treatment plans with the property that convex combinations of plans are directly deliverable. Previous methods for deliverable navigation impose restrictions on the number of apertures of the individual plans, or require that all treatment plans have identical apertures. We introduce simultaneous direct step-and-shoot optimization of multiple plans subject to constraints that some of the apertures must be identical across all plans. This method generalizes previous methods for deliverable navigation to allow for treatment plans with some apertures from a collective pool and some apertures that are individual. The method can also be used as a post-processing step to previous methods for deliverable navigation in order to improve upon their plans. By applying the method to subsets of plans in the collection representing the Pareto set, we show how it can enable convergence toward the unrestricted (non-navigable) Pareto set where all apertures are individual. (paper)

  17. A feasibility study of using conventional jaws to deliver IMRT plans in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Kim, Yongbok; Verhey, Lynn J; Xia Ping

    2007-01-01

    The aim of this study is to investigate the feasibility of using conventional jaws to deliver inverse planned intensity-modulated radiotherapy (IMRT) plans for patients with prostate cancer. For ten patients, each had one three-dimensional conformal plan (3D plan) and seven inverse IMRT plans using direct aperture optimization. For IMRT plans using conventional jaws (JO plans), the number of apertures per beam angle was set from two to seven while three apertures per beam angle were set for the multi-leaf collimator (MLC) plans. To evaluate each planning method, we compared average dose volume histograms (DVH), the conformal index (COIN), total number of segments and total number of monitor units. Among the JO plans with the number of apertures per beam angle varying from two to seven, no difference was observed in the average DVHs, and the plan conformal index became saturated after four apertures per beam angle. Subsequently, JO plans with four apertures per beam angle (JO-4A) were compared with 3D and MLC plans. Based on the average DVHs, no difference was found among 3D, JO-4A and MLC plans with regard to the planning target volume and rectum, but the DVHs for the bladder and penile bulb were significantly better with inverse IMRT plans than those with 3D plans. When compared with the plan conformity, the average COIN values for 3D, JO-4A and MLC plans were 0.61 ± 0.07, 0.73 ± 0.05 and 0.83 ± 0.05, respectively. In conclusion, inverse IMRT plans using conventional jaws are clinically feasible, achieving better plan quality than 3D-CRT plans

  18. Effect of position of blades in the treatment of IMRT; Efecto del posicionamiento de las laminas en los tratamiento de IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Perez Azorin, J. F.; Ramos Garcia, L. I.; Ortiz de Zarate Vivanco, R.; Trueba Garayo, I.; Cacicedo, J.; Hoyo, O. del

    2013-07-01

    This paper presents a method of calculation of the positions of each blade measures during treatment for all segments and the subsequent reconstruction of these positions in the planning system on the patient's physical and anatomical data. (Author)

  19. Dosimetric validation of planning system Eclipse 10 in partial breast irradiation treatments with IMRT

    International Nuclear Information System (INIS)

    Velazquez T, J. J.; Gutierrez M, J. G.; Ortiz A, C. S.; Chagoya G, A.; Gutierrez C, J. G.

    2015-10-01

    Partial breast irradiation is a new type of external radiation therapy to treat breast cancer in early clinical stages. Consist of administering to the channel surgical high doses of radiation in few treatment sessions. In this paper the dose calculations of the planning system Eclipse version 10 for a treatment of partial breast irradiation with X-rays beams (6 MV) intensity modulated were compared against the measurements made with OSL dosimeters and radio-chromic dye film. An anthropomorphic mannequin was used in which OSL dosimeters were collocated near the surface, an inside the radio-chromic dye film one plate; with this latest one dimensional dose distribution was measured. Previously dosimeters were calibrated irradiating them with a beam of X-rays 6 MV under the conditions specified in the IAEA-398 protocol. The OSL dosimeters were read in the Micro star Landauer equipment, the radio-chromic dye films were read with a scanner Epson 10000-Xl and analyzed with FilmCal and PTW Verisoft programs. The differences between measured and calculated dose were as follows: 3.6±1% for the OSL dosimeter and 96.3±1% of the analyzed points approved the gamma index criterion (3%, 3m m) when comparing the matrices of calculated dose and measured with the radio-chromic dye film. These results confirm the good dosimetric performance of planning system used under specific conditions used in the partial breast irradiation technique. (Author)

  20. Hydroxyurea with or without imatinib in the treatment of recurrent or progressive meningiomas: a randomized phase II trial by Gruppo Italiano Cooperativo di Neuro-Oncologia (GICNO).

    Science.gov (United States)

    Mazza, Elena; Brandes, Alba; Zanon, Silvia; Eoli, Marika; Lombardi, Giuseppe; Faedi, Marina; Franceschi, Enrico; Reni, Michele

    2016-01-01

    Hydroxyurea (HU) is among the most widely used salvage therapies in progressive meningiomas. Platelet-derived growth factor receptors are expressed in virtually all meningiomas. Imatinib sensitizes transformed cells to the cytotoxic effects of chemotherapeutic agents that interfere with DNA metabolism. The combination of HU with imatinib yielded intriguing results in recurrent malignant glioma. The current trial addressed the activity of this association against meningioma. Patients with recurrent or progressive WHO grade I-III meningioma, without therapeutic indication for surgery, radiotherapy, or stereotactic radiosurgery, aged 18-75 years, ECOG performance status 0-2, and not on enzyme-inducing anti-epileptic drugs were randomized to receive HU 500 mg BID ± imatinib 400 mg QD until progression, unacceptable toxicity, or patient's refusal. The primary endpoint was progression-free survival rate at 9 months (PFS-9). Between September 2009 and February 2012, 15 patients were randomized to receive HU + imatinib (N = 7; Arm A) or HU alone (N = 8; Arm B). Afterward the trial was prematurely closed due to slow enrollment rate. PFS-9 (A/B) was 0/75%, and median PFS was 4/19.5 months. Median and 2-year overall survival (A/B) rates were: 6/27.5 months; 28.5/75%, respectively. Main G3-4 toxicities were: G3 neutropenia in 1/0, G4 headache in 1/1, and G3 vomiting in 1/0. The conduction of a study in recurrent or progressive meningioma remains a challenge. Given the limited number of patients enrolled, no firm conclusions can be drawn about the combination of imatinib and HU. The optimal systemic therapy for meningioma failing surgery and radiation has yet to be identified.

  1. Treatment with intensity-modulated radiation therapy (IMRT) for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Marta, G.N.; Hanna, S.A.; Gadia, R.

    2014-11-15

    Through the development of four relevant clinical questions related with the proposed subject, we tried to present the main evidence for safety, toxicity and effectiveness using different radiotherapy techniques. The study population consisted of female patients of all ages with primary breast cancer treated with radiation therapy to the whole breast, regardless of histological type, staging, context of treatment (radical, adjuvant or palliative) and whether comorbidities were present or not. For this, a systematic review of the literature was performed in primary scientific research databases (Medline - Pubmed; Embase - Elsevier; Lilacs - Bireme; Cochrane Library - Central Register of Controlled Trials). All articles available until July 22, 2013, were included. The search strategy used for Medline research is described in Appendix. Articles were selected based on critical evaluation in search of the best available evidence. Recommendations were prepared based on discussion with the writing group, composed of three members of the Brazilian Society of Radiotherapy. The guideline was reviewed by an independent group specializing in evidence-based clinical guidelines. After completion, the guideline was made available for public consultation for 15 days and the suggestions forwarded to the writers for evaluation and consideration into the final text. Objective: to assess the most appropriate method of radiation therapy for treating patients with primary breast tumors. (author)

  2. Primary extradural meningioma arising from the calvarium | Ravi ...

    African Journals Online (AJOL)

    Meningiomas are the most common intracranial tumours. Meningiomas arising at other locations are termed primary extradural meningiomas (EDMs) and are rare. Here we report a case of EDM arising from the calvarium – a primary calvarial meningioma (PCM).

  3. Hormones, radiosurgery and virtual reality: new aspects of meningioma management

    International Nuclear Information System (INIS)

    Black, P.M.

    1997-01-01

    The understanding and management of meningiomas is changing significantly today. One of the most striking features of their pathophysiology is their predominance in women. In a series of 517 patients with meningiomas seen by the Brain Tumor Group at Brigham and Women's Hospital, the female:male ratio was 2.4:1. The progesterone receptor appears to be the major candidate to explain this difference. Progesterone receptor can be shown to be expressed in 81% of women and 40% of men with meningiomas. Surgery remains the mainstay of meningioma management. At the Brigham and Women's Hospital three-dimensional reconstruction techniques have markedly improved the ability to visualize the tumor as well as its relation to vascular structures. With MRI reconstruction, it is possible to know the tumor's relation to the sagittal and other sinuses, to identify feeders and proximity to major arteries, and to establish its location and relation to cortex by frameless stereotaxis. These techniques can be used in a virtual reality format are some of the most powerful in neurosurgery both for teaching and for the surgical procedure itself. External beam radiation has been shown by others to be an effective adjunctive treatment to prevent meningioma recurrence. Recently, linear accelerator radiosurgery and stereotactic radiotherapy have changed the pattern radiation at our institution. In a series of 56 skull base meningiomas, for example, 95% were controlled (i.e., showed now growth) over a four year period. Fractionated focal radiation potentially offers the same control rate with fewer complications. With increasing understanding and treatment possibilities, meningiomas remain one of the most intriguing and challenging tumors in the nervous system. (author)

  4. Peripheral doses from pediatric IMRT

    International Nuclear Information System (INIS)

    Klein, Eric E.; Maserang, Beth; Wood, Roy; Mansur, David

    2006-01-01

    Peripheral dose (PD) data exist for conventional fields (≥10 cm) and intensity-modulated radiotherapy (IMRT) delivery to standard adult-sized phantoms. Pediatric peripheral dose reports are limited to conventional therapy and are model based. Our goal was to ascertain whether data acquired from full phantom studies and/or pediatric models, with IMRT treatment times, could predict Organ at Risk (OAR) dose for pediatric IMRT. As monitor units (MUs) are greater for IMRT, it is expected IMRT PD will be higher; potentially compounded by decreased patient size (absorption). Baseline slab phantom peripheral dose measurements were conducted for very small field sizes (from 2 to 10 cm). Data were collected at distances ranging from 5 to 72 cm away from the field edges. Collimation was either with the collimating jaws or the multileaf collimator (MLC) oriented either perpendicular or along the peripheral dose measurement plane. For the clinical tests, five patients with intracranial or base of skull lesions were chosen. IMRT and conventional three-dimensional (3D) plans for the same patient/target/dose (180 cGy), were optimized without limitation to the number of fields or wedge use. Six MV, 120-leaf MLC Varian axial beams were used. A phantom mimicking a 3-year-old was configured per Center for Disease Control data. Micro (0.125 cc) and cylindrical (0.6 cc) ionization chambers were appropriated for the thyroid, breast, ovaries, and testes. The PD was recorded by electrometers set to the 10 -10 scale. Each system set was uniquely calibrated. For the slab phantom studies, close peripheral points were found to have a higher dose for low energy and larger field size and when MLC was not deployed. For points more distant from the field edge, the PD was higher for high-energy beams. MLC orientation was found to be inconsequential for the small fields tested. The thyroid dose was lower for IMRT delivery than that predicted for conventional (ratio of IMRT/cnventional ranged from

  5. SU-E-P-36: Evaluation of MLC Positioning Errors in Dynamic IMRT Treatments by Analyzing Dynalog Files

    International Nuclear Information System (INIS)

    Olasolo, J; Pellejero, S; Gracia, M; Gallardo, N; Martin, M; Lozares, S; Maneru, F; Bragado, L; Miquelez, S; Rubio, A

    2015-01-01

    Purpose: To assess the accuracy of MLC positioning in Varian linear accelerator, in dynamic IMRT technique, from the analysis of dynalog files generated by the MLC controller. Methods: In Clinac accelerators (pre-TrueBeam technology), control system has an approximately 50ms delay (one control cycle time). Then, the system compares the measured position to the planned position corresponding to the next control cycle. As it has been confirmed by Varian technical support, this effect causes that measured positions appear in dynalogs one cycle out of phase with respect to the planned positions. Around 9000 dynalogs have been analyzed, coming from the three linear accelerators of our center (one Trilogy and two Clinac 21EX) equipped with a Millennium 120 MLC. In order to compare our results to recent publications, leaf positioning errors (RMS and 95th percentile) are calculated with and without delay effect. Dynalogs have been analyzed using a in-house Matlab software. Results: The RMS errors were 0.341, 0.339 and 0.348mm for each Linac; being the average error 0.343 mm. The 95th percentiles of the error were 0.617, 0.607 and 0.625; with an average of 0.617mm. A recent multi-institution study carried out by Kerns et al. found a mean leaf RMS error of 0.32mm and a 95th percentile error value of 0.64mm.Without delay effect, mean leaf RMS errors obtained were 0.040, 0.042 and 0.038mm for each treatment machine; being the average 0.040mm. The 95th percentile error values obtained were 0.057, 0.058 and 0.054 mm, with an average of 0.056mm. Conclusion: Results obtained for the mean leaf RMS error and the mean 95th percentile were consistent with the multi-institution study. Calculated error statistics with delay effect are significantly larger due to the speed proportional and systematic leaf offset. Consequently it is proposed to correct this effect in dynalogs analysis to determine the MLC performance

  6. The treatment of extensive scalp lesions using coplanar and non-coplanar photon IMRT: a single institution experience

    International Nuclear Information System (INIS)

    Ostheimer, Christian; Janich, Martin; Hübsch, Patrick; Gerlach, Reinhard; Vordermark, Dirk

    2014-01-01

    This clinical study compared four different cases of extensive scalp malignancies treated by intensity-modulated radiation therapy. The merits of coplanar and non-coplanar Step-and-shoot total scalp irradiation techniques were evaluated against the background of the literature. Four patients (angiosarcoma, n=2, cutaneous B-cell non-Hodgkin lymphoma, B-NHL, n=1, mycosis fungoides, n=1) treated between 2008 and 2012 at our institution were retrospectively analyzed. For every patient with executed coplanar plan, a non-coplanar plan and vice versa has been calculated additionally for direct comparison. Three patients underwent limited surgery before radiotherapy. Individual adapted bolus material was used for every patient (helmet). Total scalp dose was 30 Gy (B-NHL, mycosis fungoides) and 50 Gy (angiosarcoma) with fractional doses of 2.0-2.5 Gy (without sequential local boost in three patients). Conformity and homogeneity indexes and dose volume histograms were used for treatment plan comparison. Dose hot spots were higher in coplanar plans (110-128% Dmax). Non-coplanar plans showed a more homogeneous dose distribution (HI = .12 - .17) and superior PTV coverage (88 - 96%). Target dose coverage was 81-117% in non-coplanar and 30-128% in coplanar plans. Coplanar plans yielded a stronger dose gradient across the target (.7-1.6 Gy/mm) compared to non-coplanar plans (.8-1.3 Gy/mm). The most conformal plan was a non-coplanar plan (CI = .7). Mean and maximum brain doses were comparable and showed an almost linear decrease between min. and max. dose. The optic chiasm and brain stem was spared most with non-coplanar plans, mean doses to the lenses ranged between 4 and 8 Gy and were higher in non-coplanar plans as were doses to the optic nerves. Radiotherapy tolerance was acceptable and acute side effects included erythema, scalp pain, alopecia and radiodermatitis which all spontaneously resolved. Two patients accomplished partial response, two patients showed complete response

  7. Olfactory groove meningiomas.

    Science.gov (United States)

    Hentschel, Stephen J; DeMonte, Franco

    2003-06-15

    Olfactory groove meningiomas (OGMs) arise over the cribriform plate and may reach very large sizes prior to presentation. They can be differentiated from tuberculum sellae meningiomas because OGMs arise more anterior in the skull base and displace the optic nerve and chiasm inferiorly rather than superiorly. The authors searched the neurosurgery database at the M. D. Anderson Cancer Center for cases of OGM treated between 1993 and 2003. The records of these patients were then reviewed retrospectively for details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status. Thirteen patients, (12 women and one man, mean age 56 years) harbored OGMs (mean size 5.7 cm). All patients underwent bifrontal craniotomies and biorbital osteotomies. There were 11 complete resections (including the hyperostotic bone and dura of the cribriform plate and any extension into the ethmoid sinuses) and two subtotal resections with minimal residual tumor left in patients with recurrent lesions. No complication directly due to the surgery occurred in any patient. There were no recurrences in a mean follow-up period of 2 years (range 0-5 years). With current microsurgical techniques, the results of OGM resection are excellent, with a high rate of total resection and a low incidence of complications. All hyperostotic bone should be removed with the dura of the anterior skull base to minimize the risk of recurrence.

  8. TU-C-17A-09: Multi-Case Knowledge-Based IMRT Treatment Planning in Head and Neck Cancer: Are Six Heads Better Than One?

    International Nuclear Information System (INIS)

    Grzetic, S; Lutzky, C; Das, S; Lo, J

    2014-01-01

    Purpose: HNC IMRT treatment planning is a challenging process that relies heavily on the planner’s experience. Previously, we used the single, best match from a library of manually planned cases to semi-automatically generate IMRT plans for a new patient. The current multi-case Knowledge Based Radiation Therapy (MC-KBRT) study utilized different matching cases for each of six individual organs-at-risk (OARs), then combined those six cases to create the new treatment plan. Methods: From a database of 103 patient plans created by experienced planners, MC-KBRT plans were created for 40 (17 unilateral and 23 bilateral) HNC “query” patients. For each case, 2D beam’s-eye-view images were used to find similar geometric “match” patients separately for each of 6 OARs. Dose distributions for each OAR from the 6 matching cases were combined and then warped to suit the query case’s geometry. The dose-volume constraints were used to create the new query treatment plan without the need for human decision-making throughout the IMRT optimization. The optimized MC-KBRT plans were compared against the clinically approved plans and Version 1 (original KBRT) using the dose metrics: mean, median, and maximum (brainstem and cord+5mm) doses. Results: Compared to Version 1, MC-KBRT had no significant reduction of the dose to any of the OARs in either unilateral/bilateral cases. Compared to the manually-planned unilateral cases, there was significant reduction of the oral cavity mean/median dose (>2Gy) at the expense of the contralateral parotid. Compared to the manually-planned bilateral cases, reduction of dose was significant in the ipsilateral parotid, larynx, and oral cavity (>3Gy mean/median) while maintaining PTV coverage. Conclusion: MC-KBRT planning in head and neck cancer generates IMRT plans with equivalent dose sparing to manually created plans. MC-KBRT using multiple case matches does not show significant dose reduction compared to using a single match case with

  9. Evaluation of preoperative embolization of meningioma

    International Nuclear Information System (INIS)

    Park, Sung Tae; Suh, Dae Chul; Lee, Ho Kyu; Choi, Choong Gon; Lee, Myung Jun; Ji, Eun Kyung; Shin, Byung Suck; Kim, Chang Jin; Kim, Jong Uk; Whang, C. Jin

    1998-01-01

    To evaluate the efficacy and safety of preoperative embolization of intrancranial meningioma.Materials and Methods : We retrospectively reviewed intrancranial meningioma patients (n=37) who underwent preoperative embolization. They were categorized into two groups, skull base lesions (n=22) and non-skull base lesions (n=15), according to tumor location. In addition, embolization results were classified by comparison between pre- and post-embolization angiography as complete (residual tumor staining 10 or 30%). In each group, estimated blood loss (EBL) was estimated by amount of intraoperative transfusion with pre- and post-operative hemoglobin level. Tumor resectability was evaluated by follow-up computed tomography. New symptoms occurring within 24 hours of embolization were considered to be those associated with embolization ; symptoms improved by conservative treatment were regarded as mild, while those resulting in new deficits were considered severe. Results : In the group with skull base lesions (n=22), complete embolization with the criteria of residual tumor staining of less than 30% was performed in 14 patients(EBL=1770ml;complete surgical removal in nine patients and incomplete removal four). Incomplete embolization was performed in eight patients (EBL=3210ml; complete and incomplete removal each in four patients). In the group with non-skull base lesions, complete embolization with the criteria of residual tumor staining of less than 10% was performed in five patients (EBL=970ml) and incomplete embolization in ten (EBL=2260ml). Complete tumor removal was possible in this group regardless of the completeness of preoperative tumor embolization. In a case of intraventricular meningioma (3%), intratumoral hemorrhage occurred on the day following embolization. Other mild post-embolization complications occurred in three cases (8%). Conclusion : Preoperative embolization can be an effective and safe procedure for meningioma and may reduce intraoperative blood

  10. Comparison of 3D anatomical dose verification and 2D phantom dose verification of IMRT/VMAT treatments for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Lin, Hailei; Huang, Shaomin; Deng, Xiaowu; Zhu, Jinhan; Chen, Lixin

    2014-01-01

    The two-dimensional phantom dose verification (2D-PDV) using hybrid plan and planar dose measurement has been widely used for IMRT treatment QA. Due to the lack of information about the correlations between the verification results and the anatomical structure of patients, it is inadequate in clinical evaluation. A three-dimensional anatomical dose verification (3D-ADV) method was used in this study to evaluate the IMRT/VMAT treatment delivery for nasopharyngeal carcinoma and comparison with 2D-PDV was analyzed. Twenty nasopharyngeal carcinoma (NPC) patients treated with IMRT/VMAT were recruited in the study. A 2D ion-chamber array was used for the 2D-PDV in both single-gantry-angle composite (SGAC) and multi-gantry-angle composite (MGAC) verifications. Differences in the gamma pass rate between the 2 verification methods were assessed. Based on measurement of irradiation dose fluence, the 3D dose distribution was reconstructed for 3D-ADV in the above cases. The reconstructed dose homogeneity index (HI), conformity index (CI) of the planning target volume (PTV) were calculated. Gamma pass rate and deviations in the dose-volume histogram (DVH) of each PTV and organ at risk (OAR) were analyzed. In 2D-PDV, the gamma pass rate (3%, 3 mm) of SGAC (99.55% ± 0.83%) was significantly higher than that of MGAC (92.41% ± 7.19%). In 3D-ADV, the gamma pass rates (3%, 3 mm) were 99.75% ± 0.21% in global, 83.82% ± 16.98% to 93.71% ± 6.22% in the PTVs and 45.12% ± 32.78% to 98.08% ± 2.29% in the OARs. The maximum HI increment in PTVnx was 19.34%, while the maximum CI decrement in PTV1 and PTV2 were -32.45% and -6.93%, respectively. Deviations in dose volume of PTVs were all within ±5%. D2% of the brainstem, spinal cord, left/right optic nerves, and the mean doses to the left/right parotid glands maximally increased by 3.5%, 6.03%, 31.13%/26.90% and 4.78%/4.54%, respectively. The 2D-PDV and global gamma pass rate might be insufficient to provide an accurate assessment for

  11. SU-F-J-13: Choosing An IMRT Technique in the Treatment of Head and Neck Cancer with Daily Localization Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Lin, T; Wang, L; Galloway, T; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Head and Neck cancer treatment with IMRT/VMAT has two choices: split-filed IMRT(SFI), in which the LAN is treated with a separate anterior field and the extended whole-field IMRT(WFI) in which LAN is included with the IMRT/VMAT field. This study shows that under the same dose limit criteria, choosing the technique becomes a critical issue if daily localization and immobilization altered the dose distribution. Methods: Nine common head-and-neck cancer cases were chosen to illustrate how the daily localization and immobilization uncertainties affect to choose between SFI and WFI. Both SFI and WFI at upper target coverage were generated with VMAT. For each case, the same planning criteria were applied to the target and critical structures; therefore, similar target coverage and dose falloff can be observed in both techniques. Thirty days of kV cone beam CT(CBCT) images on each case were also delineated with contralateral and ipsilateral target as well as larynx as critical structure. About 300 CBCT images with daily delivered doses were analyzed and compared in a form of dose-volume histograms. Results: While both plans for SFI and WFI with VMAT planning utilized and meet the criteria of D95>prescription dose and for not-involved larynx with mean dose <35Gy and V55<10%, the daily localization and immobilization has a great contribution to the resulted dose delivery. With WFI, the better daily contralateral and ipsilateral neck target coverage can reflect a simpler or shorter localization; however, a much superior avoidance (WFI: mean dose a 42.5Gy; SFI: mean dose a 18.9Gy) of the non-involved larynx from the SFI is preferred. Conclusion: Dosimetrically, SFI and WFI are equally well for head and Neck cancer treatment with VMAT technique; however, if considering the contribution of daily localization(CBCT) method uncertainties, SFI is better with sparing non-involved larynx and WFI has better target coverage.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  13. A fully electronic intensity-modulated radiation therapy quality assurance (IMRT QA) process implemented in a network comprised of independent treatment planning, record and verify, and delivery systems

    International Nuclear Information System (INIS)

    Bailey, Daniel W; Kumaraswamy, Lalith; Podgorsak, Matthew B

    2010-01-01

    The purpose of this study is to implement an electronic method to perform and analyze intensity-modulated radiation therapy quality assurance (IMRT QA) using an aSi megavoltage electronic portal imaging device in a network comprised of independent treatment planning, record and verify (R&V), and delivery systems. A verification plan was generated in the treatment planning system using the actual treatment plan of a patient. After exporting the treatment fields to the R&V system, the fields were delivered in QA mode with the aSi imager deployed. The resulting dosimetric images are automatically stored in a DICOM-RT format in the delivery system treatment console computer. The relative dose density images are subsequently pushed to the R&V system. The absolute dose images are then transferred electronically from the treatment console computer to the treatment planning system and imported into the verification plan in the dosimetry work space for further analysis. Screen shots of the gamma evaluation and isodose comparison are imported into the R&V system as an electronic file (e.g. PDF) to be reviewed prior to initiation of patient treatment. A relative dose image predicted by the treatment planning system can also be sent to the R&V system to be compared with the relative dose density image measured with the aSi imager. Our department does not have integrated planning, R&V, and delivery systems. In spite of this, we are able to fully implement a paperless and filmless IMRT QA process, allowing subsequent analysis and approval to be more efficient, while the QA document is directly attached to its specific patient chart in the R&V system in electronic form. The calculated and measured relative dose images can be compared electronically within the R&V system to analyze the density differences and ensure proper dose delivery to patients. In the absence of an integrated planning, verifying, and delivery system, we have shown that it is nevertheless possible to develop a

  14. IMRT credentialing for prospective trials using institutional virtual phantoms: results of a joint European Organization for the Research and Treatment of Cancer and Radiological Physics Center project

    International Nuclear Information System (INIS)

    Weber, Damien C; Vallet, Veronique; Molineu, Andrea; Melidis, Christos; Teglas, Vanda; Naudy, Suzanne; Moeckli, Raphael; Followill, David S; Hurkmans, Coen W

    2014-01-01

    Intensity-modulated radiotherapy (IMRT) credentialing for a EORTC study was performed using an anthropomorphic head phantom from the Radiological Physics Center (RPC; RPC PH ). Institutions were retrospectively requested to irradiate their institutional phantom (INST PH ) using the same treatment plan in the framework of a Virtual Phantom Project (VPP) for IMRT credentialing. CT data set of the institutional phantom and measured 2D dose matrices were requested from centers and sent to a dedicated secure EORTC uploader. Data from the RPC PH and INST PH were thereafter centrally analyzed and inter-compared by the QA team using commercially available software (RIT; ver.5.2; Colorado Springs, USA). Eighteen institutions participated to the VPP. The measurements of 6 (33%) institutions could not be analyzed centrally. All other centers passed both the VPP and the RPC ±7%/4 mm credentialing criteria. At the 5%/5 mm gamma criteria (90% of pixels passing), 11(92%) as compared to 12 (100%) centers pass the credentialing process with RPC PH and INST PH (p = 0.29), respectively. The corresponding pass rate for the 3%/3 mm gamma criteria (90% of pixels passing) was 2 (17%) and 9 (75%; p = 0.01), respectively. IMRT dosimetry gamma evaluations in a single plane for a H&N prospective trial using the INST PH measurements showed agreement at the gamma index criteria of ±5%/5 mm (90% of pixels passing) for a small number of VPP measurements. Using more stringent, criteria, the RPC PH and INST PH comparison showed disagreement. More data is warranted and urgently required within the framework of prospective studies

  15. Combined treatment of adenoid cystic carcinoma with cetuximab and IMRT plus C12 heavy ion boost: ACCEPT [ACC, Erbitux® and particle therapy

    Directory of Open Access Journals (Sweden)

    Hinke Axel

    2011-02-01

    Full Text Available Abstract Background Local control in adjuvant/definitive RT of adenoid cystic carcinoma (ACC is largely dose-dependent leading to the establishment of particle therapy in this indication. However, even modern techniques leave space for improvement of local control by intensification of local treatment. Radiation sensitization by exploitation of high EGFR-expression in ACC with the EGFR receptor antibody cetuximab seems promising. Methods/design The ACCEPT trial is a prospective, mono-centric, phase I/II trial evaluating toxicity (primary endpoint: acute and late effects and efficacy (secondary endpoint: local control, distant control, disease-free survival, overall survival of the combined treatment with IMRT/carbon ion boost and weekly cetuximab in 49 patients with histologically proven (≥R1-resected, inoperable or Pn+ ACC. Patients receive 18 GyE carbon ions (6 fractions and 54 Gy IMRT (2.0 Gy/fraction in combination with weekly cetuximab throughout radiotherapy. Discussion The primary objective of ACCEPT is to evaluate toxicity and feasibility of cetuximab and particle therapy in adenoid cystic carcinoma. Trial Registration Clinical Trial Identifier: NCT 01192087 EudraCT number: 2010 - 022425 - 15

  16. Combined treatment of adenoid cystic carcinoma with cetuximab and IMRT plus C12 heavy ion boost: ACCEPT [ACC, Erbitux® and particle therapy

    International Nuclear Information System (INIS)

    Jensen, Alexandra D; Nikoghosyan, Anna; Hinke, Axel; Debus, Jürgen; Münter, Marc W

    2011-01-01

    Local control in adjuvant/definitive RT of adenoid cystic carcinoma (ACC) is largely dose-dependent leading to the establishment of particle therapy in this indication. However, even modern techniques leave space for improvement of local control by intensification of local treatment. Radiation sensitization by exploitation of high EGFR-expression in ACC with the EGFR receptor antibody cetuximab seems promising. The ACCEPT trial is a prospective, mono-centric, phase I/II trial evaluating toxicity (primary endpoint: acute and late effects) and efficacy (secondary endpoint: local control, distant control, disease-free survival, overall survival) of the combined treatment with IMRT/carbon ion boost and weekly cetuximab in 49 patients with histologically proven (≥R1-resected, inoperable or Pn+) ACC. Patients receive 18 GyE carbon ions (6 fractions) and 54 Gy IMRT (2.0 Gy/fraction) in combination with weekly cetuximab throughout radiotherapy. The primary objective of ACCEPT is to evaluate toxicity and feasibility of cetuximab and particle therapy in adenoid cystic carcinoma. Clinical Trial Identifier: http://www.clinicaltrials.gov/ct2/show/NCT01192087 EudraCT number: 2010 - 022425 - 15

  17. Treatment of locally advanced carcinomas of head and neck with intensity-modulated radiation therapy (IMRT) in combination with cetuximab and chemotherapy: the REACH protocol

    International Nuclear Information System (INIS)

    Habl, Gregor; Münter, Marc W; Jensen, Alexandra D; Potthoff, Karin; Uhl, Matthias; Hof, Holger; Hajda, Jacek; Simon, Christian; Debus, Jürgen; Krempien, Robert

    2010-01-01

    Primary treatment of carcinoma of the oro-/hypopharynx or larynx may consist of combined platinum-containing chemoradiotherapy. In order to improve clinical outcome (i.e. local control/overall survival), combined therapy is intensified by the addition of the EGFR inhibitor cetuximab (Erbitux ® ). Radiation therapy (RT) is carried out as intensity-modulated RT (IMRT) to avoid higher grade acute and late toxicity by sparing of surrounding normal tissues. The REACH study is a prospective phase II study combining chemoradiotherapy with carboplatin/5-Fluorouracil (5-FU) and the monoclonal epidermal growth factor-receptor (EGFR) antibody cetuximab (Erbitux ® ) as intensity-modulated radiation therapy in patients with locally advanced squamous-cell carcinomas of oropharynx, hypopharynx or larynx. Patients receive weekly chemotherapy infusions in the 1 st and 5 th week of RT. Additionally, cetuximab is administered weekly throughout the treatment course. IMRT is delivered as in a classical concomitant boost concept (bid from fraction 16) to a total dose of 69,9 Gy. Primary endpoint of the trial is local-regional control (LRC). Disease-free survival, progression-free survival, overall survival, toxicity, proteomic and genomic analyses are secondary endpoints. The aim is to explore the efficacy as well as the safety and feasibility of this combined radioimmunchemotherapy in order to improve the outcome of patients with advanced head and neck cancer. ISRCTN87356938

  18. Treatment of locally advanced carcinomas of head and neck with intensity-modulated radiation therapy (IMRT in combination with cetuximab and chemotherapy: the REACH protocol

    Directory of Open Access Journals (Sweden)

    Simon Christian

    2010-11-01

    Full Text Available Abstract Background Primary treatment of carcinoma of the oro-/hypopharynx or larynx may consist of combined platinum-containing chemoradiotherapy. In order to improve clinical outcome (i.e. local control/overall survival, combined therapy is intensified by the addition of the EGFR inhibitor cetuximab (Erbitux®. Radiation therapy (RT is carried out as intensity-modulated RT (IMRT to avoid higher grade acute and late toxicity by sparing of surrounding normal tissues. Methods/Design The REACH study is a prospective phase II study combining chemoradiotherapy with carboplatin/5-Fluorouracil (5-FU and the monoclonal epidermal growth factor-receptor (EGFR antibody cetuximab (Erbitux® as intensity-modulated radiation therapy in patients with locally advanced squamous-cell carcinomas of oropharynx, hypopharynx or larynx. Patients receive weekly chemotherapy infusions in the 1st and 5th week of RT. Additionally, cetuximab is administered weekly throughout the treatment course. IMRT is delivered as in a classical concomitant boost concept (bid from fraction 16 to a total dose of 69,9 Gy. Discussion Primary endpoint of the trial is local-regional control (LRC. Disease-free survival, progression-free survival, overall survival, toxicity, proteomic and genomic analyses are secondary endpoints. The aim is to explore the efficacy as well as the safety and feasibility of this combined radioimmunchemotherapy in order to improve the outcome of patients with advanced head and neck cancer. Trial registration ISRCTN87356938

  19. IMRT delivery verification using a spiral phantom

    International Nuclear Information System (INIS)

    Richardson, Susan L.; Tome, Wolfgang A.; Orton, Nigel P.; McNutt, Todd R.; Paliwal, Bhudatt R.

    2003-01-01

    In this paper we report on the testing and verification of a system for IMRT delivery quality assurance that uses a cylindrical solid water phantom with a spiral trajectory for radiographic film placement. This spiral film technique provides more complete dosimetric verification of the entire IMRT treatment than perpendicular film methods, since it samples a three-dimensional dose subspace rather than using measurements at only one or two depths. As an example, the complete analysis of the predicted and measured spiral films is described for an intracranial IMRT treatment case. The results of this analysis are compared to those of a single field perpendicular film technique that is typically used for IMRT QA. The comparison demonstrates that both methods result in a dosimetric error within a clinical tolerance of 5%, however the spiral phantom QA technique provides a more complete dosimetric verification while being less time consuming. To independently verify the dosimetry obtained with the spiral film, the same IMRT treatment was delivered to a similar phantom in which LiF thermoluminescent dosimeters were arranged along the spiral trajectory. The maximum difference between the predicted and measured TLD data for the 1.8 Gy fraction was 0.06 Gy for a TLD located in a high dose gradient region. This further validates the ability of the spiral phantom QA process to accurately verify delivery of an IMRT plan

  20. Comparison of Radiation Treatment Plans for Breast Cancer between 3D Conformal in Prone and Supine Positions in Contrast to VMAT and IMRT Supine Positions

    Science.gov (United States)

    Bejarano Buele, Ana Isabel

    The treatment regimen for breast cancer patients typically involves Whole Breast Irradiation (WBI). The coverage and extent of the radiation treatment is dictated by location of tumor mass, breast tissue distribution, involvement of lymph nodes, and other factors. The current standard treatment approach used at our institution is a 3D tangential beam geometry, which involves two fields irradiating the breast, or a four field beam arrangement covering the whole breast and involved nodes, while decreasing the dose to organs as risk (OARs) such as the lung and heart. The coverage of these targets can be difficult to achieve in patients with unfavorable thoracic geometries, especially in those cases in which the planning target volume (PTV) is extended to the chest wall. It is a well-known fact that exposure of the heart to ionizing radiation has been proved to increase the subsequent rate of ischemic heart disease. In these cases, inverse planned treatments have become a proven alternative to the 3D approach. The goal of this research project is to evaluate the factors that affect our current techniques as well as to adapt the development of inverse modulated techniques for our clinic, in which breast cancer patients are one of the largest populations treated. For this purpose, a dosimetric comparison along with the evaluation of immobilization devices was necessary. Radiation treatment plans were designed and dosimetrically compared for 5 patients in both, supine and prone positions. For 8 patients, VMAT and IMRT plans were created and evaluated in the supine position. Skin flash incorporation for inverse modulated plans required measurement of the surface dose as well as an evaluation of breast volume changes during a treatment course. It was found that prone 3D conformal plans as well as the VMAT and IMRT plans are generally superior in sparing OARs to supine plans with comparable PTV coverage. Prone setup leads to larger shifts in breast volume as well as in

  1. Inverse planning IMRT

    International Nuclear Information System (INIS)

    Rosenwald, J.-C.

    2008-01-01

    The lecture addressed the following topics: Optimizing radiotherapy dose distribution; IMRT contributes to optimization of energy deposition; Inverse vs direct planning; Main steps of IMRT; Background of inverse planning; General principle of inverse planning; The 3 main components of IMRT inverse planning; The simplest cost function (deviation from prescribed dose); The driving variable : the beamlet intensity; Minimizing a 'cost function' (or 'objective function') - the walker (or skier) analogy; Application to IMRT optimization (the gradient method); The gradient method - discussion; The simulated annealing method; The optimization criteria - discussion; Hard and soft constraints; Dose volume constraints; Typical user interface for definition of optimization criteria; Biological constraints (Equivalent Uniform Dose); The result of the optimization process; Semi-automatic solutions for IMRT; Generalisation of the optimization problem; Driving and driven variables used in RT optimization; Towards multi-criteria optimization; and Conclusions for the optimization phase. (P.A.)

  2. Craniocervical Junction Meningiomas without Hydrocephalus Presenting Solely with Syncope: Report of 2 Cases.

    Science.gov (United States)

    Champagne, Pierre-Olivier; Bojanowski, Michel W

    2018-06-01

    To our knowledge, there have not been any reported cases of a meningioma of the craniocervical region presenting solely with syncope as its initial symptom. Only 1 case of meningioma presenting with syncope has been published, but it was associated with hydrocephalus. We report 2 cases of syncope caused by a craniocervical junction meningioma, with syncope being the sole presenting symptom and without hydrocephalus. We discuss the possible pathophysiology, as well as the clinical relevance of this type of presentation. We reviewed the charts, operative details, and imagery of 2 cases of meningioma in the region of the craniocervical junction, with syncope as their sole presenting feature. We also reviewed the literature. In 1 case the syncope occurred spontaneously. In the other, it occurred during a Valsalva maneuver. Both meningiomas were surgically removed via a retromastoid approach. There was no recurrence of syncope following surgery. Following a literature review, we found 1 case of posterior fossa meningioma presenting with syncope, but hydrocephalus was also present. Syncope can be the sole manifestation of a meningioma of the craniocervical junction. Such syncopes are a consequence of transient dysfunction of the autonomous pathways in the medulla and/or of the medulla's output. In the absence of other causes of syncope, a meningioma in this region, even in the absence of hydrocephalus, should not be considered as fortuitous, but rather as the actual cause of syncope. Recognizing this possibility offers the potential for proper diagnosis and appropriate treatment of the syncope. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Conversion of helical tomotherapy plans to step-and-shoot IMRT plans--Pareto front evaluation of plans from a new treatment planning system.

    Science.gov (United States)

    Petersson, Kristoffer; Ceberg, Crister; Engström, Per; Benedek, Hunor; Nilsson, Per; Knöös, Tommy

    2011-06-01

    The resulting plans from a new type of treatment planning system called SharePlan have been studied. This software allows for the conversion of treatment plans generated in a TomoTherapy system for helical delivery, into plans deliverable on C-arm linear accelerators (linacs), which is of particular interest for clinics with a single TomoTherapy unit. The purpose of this work was to evaluate and compare the plans generated in the SharePlan system with the original TomoTherapy plans and with plans produced in our clinical treatment planning system for intensity-modulated radiation therapy (IMRT) on C-arm linacs. In addition, we have analyzed how the agreement between SharePlan and TomoTherapy plans depends on the number of beams and the total number of segments used in the optimization. Optimized plans were generated for three prostate and three head-and-neck (H&N) cases in the TomoTherapy system, and in our clinical treatment planning systems (TPS) used for IMRT planning with step-and-shoot delivery. The TomoTherapy plans were converted into step-and-shoot IMRT plans in SharePlan. For each case, a large number of Pareto optimal plans were created to compare plans generated in SharePlan with plans generated in the Tomotherapy system and in the clinical TPS. In addition, plans were generated in SharePlan for the three head-and-neck cases to evaluate how the plan quality varied with the number of beams used. Plans were also generated with different number of beams and segments for other patient cases. This allowed for an evaluation of how to minimize the number of required segments in the converted IMRT plans without compromising the agreement between them and the original TomoTherapy plans. The plans made in SharePlan were as good as or better than plans from our clinical system, but they were not as good as the original TomoTherapy plans. This was true for both the head-and-neck and the prostate cases, although the differences between the plans for the latter were

  4. SU-F-BRE-13: Replacing Pre-Treatment Phantom QA with 3D In-Vivo Portal Dosimetry for IMRT Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Stroom, J; Vieira, S; Greco, C [Champalimaud Foundation, Lisbon (Portugal); Olaciregui-Ruiz, I; Rozendaal, R; Herk, M van [The Netherlands Cancer Institute, Amsterdam, North Holland (Netherlands); Moser, E [Champalimaud Foundation, Lisbon, Lisbon (Portugal)

    2014-06-15

    Purpose: Pre-treatment QA of individual treatment plans requires costly linac time and physics effort. Starting with IMRT breast treatments, we aim to replace pre-treatment QA with in-vivo portal dosimetry. Methods: Our IMRT breast cancer plans are routinely measured using the ArcCheck device (SunNuclear). 2D-Gamma analysis is performed with 3%/3mm criteria and the percentage of points with gamma<1 (nG1) is calculated within the 50% isodose surface. Following AAPM recommendations, plans with nG1<90% are approved; others need further inspection and might be rejected. For this study, we used invivo portal dosimetry (IPD) to measure the 3D back-projected dose of the first three fractions for IMRT breast plans. Patient setup was online corrected before for all measured fractions. To reduce patient related uncertainties, the three IPD results were averaged and 3D-gamma analysis was applied with abovementioned criteria . For a subset of patients, phantom portal dosimetry (PPD) was also performed on a slab phantom. Results: Forty consecutive breast patients with plans that fitted the EPID were analysed. The average difference between planned and IPD dose in the reference point was −0.7+/−1.6% (1SD). Variation in nG1 between the 3 invivo fractions was about 6% (1SD). The average nG1 for IPD was 89+/−6%, worse than ArcCheck (95+/−3%). This can be explained by patient related factors such as changes in anatomy and/or model deficiencies due to e.g. inhomogeneities. For the 20 cases with PPD, mean nG1 was equal to ArcCheck values, which indicates that the two systems are equally accurate. These data therefore suggest that proper criteria for 3D invivo verification of breast treatments should be nG1>80% instead of nG1>90%, which, for our breast cases, would result in 5% (2/40) further inspections. Conclusion: First-fraction in-vivo portal dosimetry using new gamma-evaluation criteria will replace phantom measurements in our institution, saving resources and yielding 3D

  5. Successful radiopeptide targeting of metastatic anaplastic meningioma: Case report

    International Nuclear Information System (INIS)

    Sabet, Amir; Ahmadzadehfar, Hojjat; Herrlinger, Ulrich; Wilinek, Winfried; Biersack, Hans-Jürgen; Ezziddin, Samer

    2011-01-01

    A patient with anaplastic meningioma and lung metastases resistant to conventional treatment underwent radiopeptide therapy with 177Lu- DOTA-octreotate in our institute. The treatment resulted in significant improvement in patient's quality of life and inhibition of tumor progression. This case may eventually help to establish the value of radiopeptide therapy in patients with this rare condition

  6. Successful radiopeptide targeting of metastatic anaplastic meningioma: Case report

    Directory of Open Access Journals (Sweden)

    Biersack Hans-Jürgen

    2011-08-01

    Full Text Available Abstract A patient with anaplastic meningioma and lung metastases resistant to conventional treatment underwent radiopeptide therapy with 177Lu- DOTA-octreotate in our institute. The treatment resulted in significant improvement in patient's quality of life and inhibition of tumor progression. This case may eventually help to establish the value of radiopeptide therapy in patients with this rare condition.

  7. SU-E-T-06: A Comparison of IMRT Treatment of Esophageal Carcinoma in Elekta-Precise and Varian23EX Linac

    Energy Technology Data Exchange (ETDEWEB)

    Bai, W; Fan, X; Qiu, R; Qiao, X; Zhang, R [Hebei Medical University Fourth Hospital, Shijiazhuang, Hebei (China)

    2014-06-01

    Purpose: To compare and analyze the characteristics of static intensity-modulated radiotherapy (IMRT) plans designed on Elekta and Varian Linac in different esophageal cancer(EC), exploring advantages and disadvantages of different vendor Linac, thus can be better serve for clinical. Methods: Twenty-four patients with EC were selected, including 6 cases located in the cervical, upper, middle and the lower thorax, respectively. Two IMRT plans were generated with the Oncentra planning system: in Elekta and Varian Linac, prescription dose of 60Gy in 30 fractions to the PTV. We examined the dose-volume histogram parameters of PTV and the organs at risk (OAR) such as lungs, spinal cord and heart, and additional Monitor units(MU), treatment time, Homogeneity index(HI), Conformity index(CI) and Gamma index comparisons were performed. Results: All plans resulted in abundant dose coverage of PTV for EC of different locations. The doses to PTV, HI and OAR in Elekta plans were not statistically different in comparison with Varian plans, with the following exceptions: in cervical, upper and lower thoracic EC the PTV's CI, and in middle thorax EC PTV's D2, D50, V105 and PTV-average were better in Elekta plans than in Varian plans. In the cervical, upper and the middle thorax EC, treatment time were significantly decreased in Varian plans as against Elekta plans, while in the lower thoracic EC treatment time were no striking difference. MUs and gamma index were similar between the two Linac plans. Conclusion: For the the middle thorax EC Varian plans is better than Elekta plans, not only in treatment time but in the PTV dose; while for the lower thorax EC Elekta plans is the first choice for better CI; for the other part of the EC usually Elekta plans can increase the CI, while Varian plans can reduce treatment time, can be selected according to the actual situation of the patient treatment.

  8. Posterior fossa meningioma (surgical experiences) | Moussa ...

    African Journals Online (AJOL)

    Symptoms included headache (75%), cerebellar manifestations (60%), cranial nerve affection (40%) and hearing disturbances (15%). Most of the cases (50%) were cerebellopontine angle meningioma while the least (5%) were foramen magnum meningioma. Surgical approaches used included retrosigmoid approach ...

  9. SU-F-T-373: Monte Carlo Versus Pencil Beam Dose Calculation for Spine SBRT Treatments Using HybridARC and Sliding Windows IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Venencia, C; Pino, M; Caussa, L; Garrigo, E [Instituto de Radioterapia - Fundacion Marie Curie, Cordoba (Argentina); Molineu, A [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: The purpose of this work was to quantify the dosimetric impact of Monte Carlo (MC) dose calculation algorithm compared to Pencil Beam (PB) on Spine SBRT with HybridARC (HA) and sliding windows IMRT (dMLC) treatment modality. Methods: A 6MV beam (1000MU/min) produced by a Novalis TX (BrainLAB-Varian) equipped with HDMLC was used. HA uses 1 arc plus 8 IMRT beams (arc weight between 60–40%) and dIMRT 15 beams. Plans were calculated using iPlan v.4.5.3 (BrainLAB) and the treatment dose prescription was 27Gy in 3 fractions. Dose calculation was done by PB (4mm spatial resolution) with heterogeneity correction and MC dose to water (4mm spatial resolution and 4% mean variance). PTV and spinal cord dose comparison were done. Study was done on 12 patients. IROC Spine Phantom was used to validate HA and quantify dose variation using PB and MC algorithm. Results: The difference between PB and MC for PTV D98%, D95%, Dmean, D2% were 2.6% [−5.1, 6.8], 0.1% [−4.2, 5.4], 0.9% [−1.5, 3.8] and 2.4% [−0.5, 8.3]. The difference between PB and MC for spinal cord Dmax, D1.2cc and D0.35cc were 5.3% [−6.4, 18.4], 9% [−7.0, 17.0] and 7.6% [−0.6, 14.8] respectively. IROC spine phantom shows PTV TLD dose variation of 0.98% for PB and 1.01% for MC. Axial and sagittal film plane gamma index (5%-3mm) was 95% and 97% for PB and 95% and 99% for MC. Conclusion: PB slightly underestimates the dose for the PTV. For the spinal cord PB underestimates the dose and dose differences could be as high as 18% which could have unexpected clinical impact. CI shows no variation between PB and MC for both treatment modalities Treatment modalities have no impact with the dose calculation algorithms used. Following the IROC pass-fail criteria, treatment acceptance requirement was fulfilled for PB and MC.

  10. Intracranial meningioma as primary presentation for an undiagnosed collision metastatic breast cancer: Case report and literature review.

    Science.gov (United States)

    Farrag, Ashraf; Ansari, Jawaher; Ali, Muhammad; Sunbuli, Ghanem; Kassem, Hassan; Al Hamad, Abdul-Aziz

    2018-05-01

    Intracranial metastasis from breast cancer is a relatively common finding, however, the appearance of breast cancer metastasis in a meningioma is very rare. Several cases of tumor-to-tumor metastasis and collision tumors have been reported previously, with meningioma being implicated as the most common benign intracranial neoplasm to harbour the metastasis. Occasionally, the discovery of a tumor-to-meningioma metastasis may herald the diagnosis of an occult primary malignancy. Careful histopathological assessment of the resected meningioma specimen is pivotal to the management of these patients, as this will alter the treatment plan and prognosis considerably. Intracranial meningioma with collision breast cancer as primary presentation of an undiagnosed metastatic breast cancer is extremely rare. The current study presents a case of intracranial meningioma with collision breast cancer as a primary presentation, and reviews the available evidence for this unusual disease entity.

  11. Letter to the Editor on 'Single-Arc IMRT?'.

    Science.gov (United States)

    Otto, Karl

    2009-04-21

    In the note 'Single Arc IMRT?' (Bortfeld and Webb 2009 Phys. Med. Biol. 54 N9-20), Bortfeld and Webb present a theoretical investigation of static gantry IMRT (S-IMRT), single-arc IMRT and tomotherapy. Based on their assumptions they conclude that single-arc IMRT is inherently limited in treating complex cases without compromising delivery efficiency. Here we present an expansion of their work based on the capabilities of the Varian RapidArc single-arc IMRT system. Using the same theoretical framework we derive clinically deliverable single-arc IMRT plans based on these specific capabilities. In particular, we consider the range of leaf motion, the ability to rapidly and continuously vary the dose rate and the choice of collimator angle used for delivery. In contrast to the results of Bortfeld and Webb, our results show that single-arc IMRT plans can be generated that closely match the theoretical optimum. The disparity in the results of each investigation emphasizes that the capabilities of the delivery system, along with the ability of the optimization algorithm to exploit those capabilities, are of particular importance in single-arc IMRT. We conclude that, given the capabilities available with the RapidArc system, single-arc IMRT can produce complex treatment plans that are delivered efficiently (in approximately 2 min).

  12. Cathepsin L in human meningiomas

    International Nuclear Information System (INIS)

    Trinkaus, M.; Lah, T.T.; Vranic, A.; Dolenc, V.V.

    2003-01-01

    Background. Although meningiomas are considered as benign tumours, about 10% comprise a subgroup of a typical meningiomas, classified as WHO grade II, with greater likelihood of recurrences and/or aggressive behaviour, including the possibility of brain tissue invasion. The lysosomal cysteine endopeptidase cathepsin L plays a role in tumour cell invasion and malignant progression of cancer, and has been suggested as a prognostic marker for certain types of tumours. Results. In our study, we compared the expression of cathepsin L in 30 meningiomas with their clinical invasiveness. Cathepsin L was determined by immunohistochemical analysis, quantitative real-time RT-PCR and Northern blot. We showed that expression of cathepsin L protein was significantly higher (p=0.019) in 9 atypical than in 21 benign meningiomas. Within the group of benign meningiomas, expression of cathepsin L was significantly lower in the transitional histological subtype. We measured the levels of cathepsin LA type of RNA splicing variants: LA, LAI and LAII, but not LAIII and not the LB variant, the latter being several times lower than the LA type. In contrast to protein levels, the levels of cathepsin LA, AI, AII RNA variants did not differ between histological subtypes or between benign and a typical meningiomas. The expression of total measured cathepsin LA, AI, AII RNA variants in the samples, taken from the centre and the periphery of the tumours, also showed no statistically significant differences. Conclusions. These results indicate that cathepsin L protein over-expression may contribute to the development of the aggressive and possibly invasive character of a typical meningiomas and that it may be up regulated at the translational level. (author)

  13. A national dosimetric audit of IMRT

    International Nuclear Information System (INIS)

    Budgell, Geoff; Berresford, Joe; Trainer, Michael; Bradshaw, Ellie; Sharpe, Peter; Williams, Peter

    2011-01-01

    Background and purpose: A dosimetric audit of IMRT has been carried out within the UK between June 2009 and March 2010 in order to provide an independent check of safe implementation and to identify problems in the modelling and delivery of IMRT. Methods and materials: A mail based audit involving film and alanine dosimeters was utilized. Measurements were made for each individual field in an IMRT plan isocentrically in a flat water-equivalent phantom at a depth of 5 cm. The films and alanine dosimeters were processed and analysed centrally; additional ion chamber measurements were made by each participating centre. Results: 57 of 62 centres participated, with a total of 78 plans submitted. For the film measurements, all 176 fields from the less complex IMRT plans (including prostate and breast plans) achieved over 95% pixels passing a gamma criterion of 3%/3 mm within the 20% isodose. For the more complex IMRT plans (mainly head and neck) 8/245 fields (3.3%) achieved less than 95% pixels passing a 4%/4 mm gamma criterion. Of the alanine measurements, 4/78 (5.1%) of the measurements differed by >5% from the dose predicted by the treatment planning system. Three of these were large deviations of -77.1%, -29.1% and 14.1% respectively. Excluding the three measurements outside 10%, the mean difference was 0.05% with a standard deviation of 1.5%. The out of tolerance results have been subjected to further investigations. Conclusions: A dosimetric audit has been successfully carried out of IMRT implementation by over 90% of UK radiotherapy departments. The audit shows that modelling and delivery of IMRT is accurate, suggesting that the implementation of IMRT has been carried out safely.

  14. Histological-subtypes and anatomical location correlated in meningeal brain tumors (meningiomas

    Directory of Open Access Journals (Sweden)

    Abdul Rashid Bhat

    2014-01-01

    Full Text Available Context: Not enough literature is available to suggest a link between the histological subtypes of intracranial meningeal brain tumors, called ′meningiomas′ and their location of origin. Aim: The evidence of correlation between the anatomical location of the intracranial meningiomas and the histopathological grades will facilitate specific diagnosis and accurate treatment. Materials and Methods: The retrospective study was conducted in a single high-patient-inflow Neurosurgical Center, under a standard and uniform medical protocol, over a period of 30 years from December 1982 to December 2012. The records of all the operated 729 meningiomas were analyzed from the patient files in the Medical Records Department. The biodata, x-rays, angiography, computed tomography (CT scans, imaging, histopathological reports, and mortality were evaluated and results drawn. Results: The uncommon histopathological types of meningiomas (16.88% had common locations of origin in the sphenoid ridge, posterior parafalcine, jugular foramen, peritorcular and intraventricular regions, cerebellopontine angle, and tentorial and petroclival areas. The histopathological World Health Organization (WHO Grade I (Benign Type meningiomas were noted in 89.30%, WHO Grade II (Atypical Type in 5.90%, and WHO Grade III (Malignant Type in 4.80% of all meningiomas. Meningiomas of 64.60% were found in females, 47.32% were in the age group of 41-50 years, and 3.43% meningiomas were found in children. An overall mortality of 6.04% was noted. WHO Grade III (malignant meningiomas carried a high mortality (25.71% and the most common sites of meningiomas with high mortality were: The cerebellopontine angles, intraventricular region, sphenoid ridge, tuberculum sellae, and the posterior parafalcine areas. Conclusion: The correlation between the histological subtypes and the anatomical location of intracranial meningeal brain tumors, called meningiomas, is evident, but further research is

  15. CAPIRI-IMRT: a phase II study of concurrent capecitabine and irinotecan with intensity-modulated radiation therapy for the treatment of recurrent rectal cancer.

    Science.gov (United States)

    Cai, Gang; Zhu, Ji; Palmer, Joshua D; Xu, Ye; Hu, Weigang; Gu, Weilie; Cai, Sanjun; Zhang, Zhen

    2015-02-28

    This study investigated the local effect and acute toxicity of irinotecan and capecitabine with concurrent intensity-modulated radiation therapy (IMRT) for the treatment of recurrent rectal cancer without prior pelvic irradiation. Seventy-one patients diagnosed with recurrent rectal cancer who did not previously receive pelvic irradiation were treated in our hospital from October 2009 to July 2012. Radiotherapy was delivered to the pelvis, and IMRT of 45 Gy (1.8 Gy per fraction), followed by a boost of 10 Gy to 16 Gy (2 Gy per fraction), was delivered to the recurrent sites. The concurrent chemotherapy regimen was 50 mg/m(2) irinotecan weekly and 625 mg/m(2) capecitabine twice daily (Mon-Fri). Radical surgery was recommended for medically fit patients without extra-pelvic metastases. The patients were followed up every 3 months. Tumor response was evaluated using CT/MRIs according to the RECIST criteria or postoperative pathological findings. NCI-CTC 3.0 was used to score the toxicities. Forty-eight patients (67.6%) had confirmed recurrent rectal cancer without extra pelvic metastases, and 23 patients (32.4%) had extra pelvic metastases. Fourteen patients (19.7%) underwent radical resections (R0) post-chemoradiation. A pathologic complete response was observed in 7 of 14 patients. A clinical complete response was observed in 4 patients (5.6%), and a partial response was observed in 22 patients (31.0%). Only 5 patients (7.0%) showed progressive disease during or shortly after treatment. Of 53 symptomatic patients, clinical complete and partial symptom relief with chemoradiation was achieved in 56.6% and 32.1% of patients, respectively. Only 2 patients (2.8%) experienced grade 4 leukopenia. The most common grade 3 toxicity was diarrhea (16 [22.5%] patients). The median follow-up was 31 months. The cumulative local progression-free survival rate was 74.2% and 33.9% at 1 and 3 years after chemoradiation, respectively. The cumulative total survival rate was 80.1% and 36

  16. Computer-based radiological longitudinal evaluation of meningiomas following stereotactic radiosurgery.

    Science.gov (United States)

    Shimol, Eli Ben; Joskowicz, Leo; Eliahou, Ruth; Shoshan, Yigal

    2018-02-01

    Stereotactic radiosurgery (SRS) is a common treatment for intracranial meningiomas. SRS is planned on a pre-therapy gadolinium-enhanced T1-weighted MRI scan (Gd-T1w MRI) in which the meningioma contours have been delineated. Post-SRS therapy serial Gd-T1w MRI scans are then acquired for longitudinal treatment evaluation. Accurate tumor volume change quantification is required for treatment efficacy evaluation and for treatment continuation. We present a new algorithm for the automatic segmentation and volumetric assessment of meningioma in post-therapy Gd-T1w MRI scans. The inputs are the pre- and post-therapy Gd-T1w MRI scans and the meningioma delineation in the pre-therapy scan. The output is the meningioma delineations and volumes in the post-therapy scan. The algorithm uses the pre-therapy scan and its meningioma delineation to initialize an extended Chan-Vese active contour method and as a strong patient-specific intensity and shape prior for the post-therapy scan meningioma segmentation. The algorithm is automatic, obviates the need for independent tumor localization and segmentation initialization, and incorporates the same tumor delineation criteria in both the pre- and post-therapy scans. Our experimental results on retrospective pre- and post-therapy scans with a total of 32 meningiomas with volume ranges 0.4-26.5 cm[Formula: see text] yield a Dice coefficient of [Formula: see text]% with respect to ground-truth delineations in post-therapy scans created by two clinicians. These results indicate a high correspondence to the ground-truth delineations. Our algorithm yields more reliable and accurate tumor volume change measurements than other stand-alone segmentation methods. It may be a useful tool for quantitative meningioma prognosis evaluation after SRS.

  17. Implementation of intensity-modulated conformational radiotherapy (IMRT) for the treatment of cervical cancers at the Alexis-Vautrin Centre; Implementation de la radiotherapie conformationnelle avec modulation d'intensite (RCMI) pour le traitement des cancers du col uterin au centre Alexis-Vautrin

    Energy Technology Data Exchange (ETDEWEB)

    Renard-Oldrini, S.; Brunaud, C.; Marchesi, V.; Tournier-Rangeard, L.; Peiffert, D. [Centre Alexis-Vautrin, 54 - Nancy (France)

    2010-10-15

    The authors discuss the comparison of the treatment plans of eleven patients treated either by conformational irradiation for seven of them, or by intensity-modulated conformational irradiation (IMRT) for four of them. The IMRT results in a good target volume coverage, can better protect the intestine than the conventional irradiation, and therefore is very promising, notably in terms of digestive toxicity. Short communication

  18. Influence of daily setup measurements and corrections on the estimated delivered dose during IMRT treatment of prostate cancer patients

    International Nuclear Information System (INIS)

    Haaren, Paul M.A. van; Bel, Arjan; Hofman, Pieter; Vulpen, Marco van; Kotte, Alexis N.T.J.; Heide, Uulke A. van der

    2009-01-01

    Purpose: To evaluate the impact of marker-based position verification, using daily imaging and an off-line correction protocol, by calculating the delivered dose to prostate, rectum and bladder. Methods: Prostate cancer patients (n = 217) were treated with IMRT, receiving 35 daily fractions. Plans with five beams were optimized taking target coverage (CTV, boost) and organs-at-risk (rectum and bladder) into account. PTV margins were 8 mm. Prostate position was verified daily using implanted fiducial gold markers by imaging the first segment of all the five beams on an EPID. Setup deviations were corrected off-line using an adapted shrinking-action-level protocol. The estimated delivered dose, including daily organ movements, was calculated using a version of PLATO's dose engine, enabling batch processing of large numbers of patients. The dose was calculated ± inclusion of setup corrections, and was evaluated relative to the original static plan. The marker-based measurements were considered representative for all organs. Results: Daily organ movements would result in an underdosage of 2-3 Gy to CTV and boost volume relative to the original plan, which was prevented by daily setup corrections. The dose to rectum and bladder was on average unchanged, but a large spread was introduced by organ movements, which was reduced by including setup corrections. Conclusions: Without position verification and setup corrections, margins of 8mm would be insufficient to account for position uncertainties during IMRT of prostate cancer. With the daily off-line correction protocol, the remaining variations are accommodated adequately

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  20. [Microsurgical removal of olfactory groove meningiomas].

    Science.gov (United States)

    Liang, Ri-Sheng; Zhou, Liang-Fu; Mao, Ying; Zhang, Rong; Yang, Wei-Zhong

    2011-01-01

    To explore an effective method for further improving the surgical results of treatment of olfactory groove meningiomas. Sixty seven cases of olfactory groove meningiomas were treated by microneurosurgery, among which fifty seven were de novo cases, eight were recurrent tumors and the other two re-recurrent cases. Modified Derome approach was used in 12 cases, bilateral subfrontal approach in 28 cases, modified pterional approach in 21 cases and unilateral subfrontal approach in six cases. Tumors were resected microsurgically with radical removal of invaded dura, bone, and paranasal sinus mucosa. Reconstruction was performed in patients with skull base defect. Simpson grade I removal was accomplished in 59 cases, grade II in seven cases and grade IV in one case. Among 57 patients with de novo tumor, Simpson I resection was accomplished in 54 cases. Postoperative rhinorrhea and intracranial infection occurred in one case and was cured after temporal lumbar CSF drainage and antibiotic therapy. Two patients (2.9%) died within one month after operation, i.e.one aged patient of heart failure and the other of severe hypothalamus complication. Forty seven patients (72.3%) were followed up from one to ten years with an average of five years and four months. With the exception of two cases died, among the alive 45 patients, there were only three patients with tumor recurrence, which had undergone Simpson II or IV tumor resection. No recurrence was found in cases with Simpson I tumor removal. Previous blurred vision was not improved in three patients, hemiparalysis in two patients, and the other patients recovered well, resuming previous jobs or being able to take care themselves. Total tumor removal (Simpson I) should be the surgical goal for treatment of olfactory groove meningiomas, especially for de novo cases. An appropriate approach is fundamental in the effort to remove an OGM totally. Appropriate anterior skull base reconstruction with vascularized material is

  1. AP-PA field orientation followed by IMRT reduces lung exposure in comparison to conventional 3D conformal and sole IMRT in centrally located lung tumors

    Directory of Open Access Journals (Sweden)

    Soyfer Viacheslav

    2012-02-01

    Full Text Available Abstract Little attention has been paid to the fact that intensity modulated radiation therapy (IMRT techniques do not easily enable treatment with opposed beams. Three treatment plans (3 D conformal, IMRT, and combined (anterior-posterior-posterio-anterior (AP-PA + IMRT of 7 patients with centrally-located lung cancer were compared for exposure of lung, spinal cord and esophagus. Combined IMRT and AP-PA techniques offer better lung tissue sparing compared to plans predicated solely on IMRT for centrally-located lung tumors.

  2. A retrospective planning analysis comparing intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) using two optimization algorithms for the treatment of early-stage prostate cancer

    International Nuclear Information System (INIS)

    Elith, Craig A; Dempsey, Shane E; Warren-Forward, Helen M

    2013-01-01

    The primary aim of this study is to compare intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) for the radical treatment of prostate cancer using version 10.0 (v10.0) of Varian Medical Systems, RapidArc radiation oncology system. Particular focus was placed on plan quality and the implications on departmental resources. The secondary objective was to compare the results in v10.0 to the preceding version 8.6 (v8.6). Twenty prostate cancer cases were retrospectively planned using v10.0 of Varian's Eclipse and RapidArc software. Three planning techniques were performed: a 5-field IMRT, VMAT using one arc (VMAT-1A), and VMAT with two arcs (VMAT-2A). Plan quality was assessed by examining homogeneity, conformity, the number of monitor units (MUs) utilized, and dose to the organs at risk (OAR). Resource implications were assessed by examining planning and treatment times. The results obtained using v10.0 were also compared to those previously reported by our group for v8.6. In v10.0, each technique was able to produce a dose distribution that achieved the departmental planning guidelines. The IMRT plans were produced faster than VMAT plans and displayed improved homogeneity. The VMAT plans provided better conformity to the target volume, improved dose to the OAR, and required fewer MUs. Treatments using VMAT-1A were significantly faster than both IMRT and VMAT-2A. Comparison between versions 8.6 and 10.0 revealed that in the newer version, VMAT planning was significantly faster and the quality of the VMAT dose distributions produced were of a better quality. VMAT (v10.0) using one or two arcs provides an acceptable alternative to IMRT for the treatment of prostate cancer. VMAT-1A has the greatest impact on reducing treatment time

  3. Tomotherapy: IMRT and tomographic verification

    International Nuclear Information System (INIS)

    Mackie, T.R.

    2000-01-01

    Full text: External beam radiation therapy delivery began around the turn of the century with the use of one or a few kilovoltage beams directed to the presumed site of the tumor. Often the treatment lasted until erythema dose was reached. Delivering the beams rotationally allowed the dose to be focused on the tumor and the skin to be spared. With the advent of megavoltage radiation therapy in the 1950's, using Co-60 teletherapy and betatrons, the treatment could once again be delivered from only a few beam directions and the dose to the skin would be kept below tolerance. Fields were shaped by lead blocks and later by custom-made blocks fabricated from low-melting temperature heavy metal. Linear accelerators did not fundamentally change the way in which radiation was delivered. It is likely that this delivery paradigm would not have changed had it not been for the advent of computers. Brahme and Cormack showed in the late 1980's that highly conformal treatments could be delivered with non-uniform intensity beams. At that time the only way in which the intensity modulated beams could be delivered was using custom-milled compensators. Fabricating and using compensators for multiple fields is time-consuming and labor-intensive. Serial tomotherapy was the first successful delivery method for IMRT and went back to the earlier practice of rotation therapy. The NOMOS Peacock system uses a binary (on-off) multileaf collimator (MLC) system to modulate a fan beam of radiation. It uses an optimization system to determine when leaves should be opened and closed. The system delivers two beam slices at once and the couch is indexed to the next slices by precisely translating the couch. This approach was first used in 1994 and to-date has treated several thousand patients. Prior to the advent of IMRT, accelerator vendors introduced the multileaf collimator (MLC) to provide field shaping without the need to fabricate custom blocking. Most new linear accelerator purchases today

  4. Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the hypofractionated treatment of high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Yartsev Slav

    2008-01-01

    Full Text Available Abstract Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p dose, 1–3 Gy over 5/10 dose points; p Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.

  5. TH-EF-BRB-01: BEST IN PHYSICS (THERAPY): Dosimetric Comparison of 4π and Clinical IMRT for Cortex-Sparing High-Grade Glioma Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Woods, K; Tran, A; Yu, V; Nguyen, D; Sheng, K [UCLA School of Medicine, Los Angeles, CA (United States); Karunamuni, R; Hattangadi-Gluth, J [University of California, San Diego, La Jolla, CA (United States)

    2016-06-15

    Purpose: Thinning of the cerebral cortex has been observed in patients treated with fractionated partial brain radiation therapy and may contribute to cognitive decline following treatment. The extent of this thinning is dose-dependent, and was shown comparable to that of neurodegenerative diseases such as Alzheimer’s disease at one year post-therapy. This study investigates whether 4π radiotherapy can enable better sparing of the cortex and other critical structures when compared to conventional clinical IMRT plans. Methods: Clinical cortex-sparing IMRT plans for 15 high-grade glioma patients were included in this study. 4π radiotherapy plans were created for each patient with 20 intensity-modulated non-coplanar fields selected with a greedy column-generation optimization. All plans were normalized to deliver 100% of the prescribed dose to 95% of the planning target volume (PTV). The mean and maximum dose to the cerebral cortex and other organs at risk (OARs) were compared for the two plan types, as well as the conformity index (CI), homogeneity index (HI), and 50% dose spillage volume (R50). Results: The 4π plans significantly reduced the mean cortex dose by an average of 16% (range 6% to 27%) compared to the clinical plans. The mean dose to every other OAR compared was also reduced by 15% to 43%, with statistically significant reductions to the brainstem, chiasm, eyes, optic nerves, subcortical whit, and hippocampus. The average maximum doses were also reduced for 10/12 OARs. The R50 was significantly reduced with the 4π plans (>14%) and the homogeneity index was significantly improved. Conclusion: 4π enables significant sparing of the cerebral cortex when treating high-grade gliomas with fractionated partial brain radiation therapy, potentially reducing the risk of harmful dose-dependent cortical thinning. NIH R43CA183390, NIH R01CA188300, Varian Medical Systems.

  6. Clinical potential of meningioma genomic insights: a practical review for neurosurgeons.

    Science.gov (United States)

    Karsy, Michael; Azab, Mohammed A; Abou-Al-Shaar, Hussam; Guan, Jian; Eli, Ilyas; Jensen, Randy L; Ormond, D Ryan

    2018-06-01

    Meningiomas are among the most common intracranial pathological conditions, accounting for 36% of intracranial lesions treated by neurosurgeons. Although the majority of these lesions are benign, the classical categorization of tumors by histological type or World Health Organization (WHO) grade has not fully captured the potential for meningioma progression and recurrence. Many targeted treatments have failed to generate a long-lasting effect on these tumors. Recently, several seminal studies evaluating the genomics of intracranial meningiomas have rapidly changed the understanding of the disease. The importance of NF2 (neurofibromin 2), TRAF7 (tumor necrosis factor [TNF] receptor-associated factor 7), KLF4 (Kruppel-like factor 4), AKT1, SMO (smoothened), PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha), and POLR2 (RNA polymerase II subunit A) demonstrates that there are at least 6 distinct mutational classes of meningiomas. In addition, 6 methylation classes of meningioma have been appreciated, enabling improved prediction of prognosis compared with traditional WHO grades. Genomic studies have shed light on the nature of recurrent meningioma, distinct intracranial locations and mutational patterns, and a potential embryonic cancer stem cell-like origin. However, despite these exciting findings, the clinical relevance of these findings remains elusive. The authors review the key findings from recent genomic studies in meningiomas, specifically focusing on how these findings relate to clinical insights for the practicing neurosurgeon.

  7. The effect of respiratory cycle and radiation beam-on timing on the dose distribution of free-breathing breast treatment using dynamic IMRT

    International Nuclear Information System (INIS)

    Ding Chuxiong; Li Xiang; Huq, M. Saiful; Saw, Cheng B.; Heron, Dwight E.; Yue, Ning J.

    2007-01-01

    In breast cancer treatment, intensity-modulated radiation therapy (IMRT) can be utilized to deliver more homogeneous dose to target tissues to minimize the cosmetic impact. We have investigated the effect of the respiratory cycle and radiation beam-on timing on the dose distribution in free-breathing dynamic breast IMRT treatment. Six patients with early stage cancer of the left breast were included in this study. A helical computed tomography (CT) scan was acquired for treatment planning. A four-dimensional computed tomography (4D CT) scan was obtained right after the helical CT scan with little or no setup uncertainty to simulate patient respiratory motion. After optimizing based on the helical CT scan, the sliding-window dynamic multileaf collimator (DMLC) leaf sequence was segmented into multiple sections that corresponded to various respiratory phases per respiratory cycle and radiation beam-on timing. The segmented DMLC leaf sections were grouped according to respiratory phases and superimposed over the radiation fields of corresponding 4D CT image set. Dose calculation was then performed for each phase of the 4D CT scan. The total dose distribution was computed by accumulating the contribution of dose from each phase to every voxel in the region of interest. This was tracked by a deformable registration program throughout all of the respiratory phases of the 4D CT scan. A dose heterogeneity index, defined as the ratio between (D 20 -D 80 ) and the prescription dose, was introduced to numerically illustrate the impact of respiratory motion on the dose distribution of treatment volume. A respiratory cycle range of 4-8 s and randomly distributed beam-on timing were assigned to simulate the patient respiratory motion during the free-breathing treatment. The results showed that the respiratory cycle period and radiation beam-on timing presented limited impact on the target dose coverage and slightly increased the target dose heterogeneity. This motion impact

  8. SU-F-T-227: A Comprehensive Patient Specific, Structure Specific, Pre-Treatment 3D QA Protocol for IMRT, SBRT and VMAT - Clinical Experience

    Energy Technology Data Exchange (ETDEWEB)

    Gueorguiev, G; Cotter, C; Young, M; Toomeh, D [Massachusetts General Hospital Boston MA (United States); University of Massachusetts Lowell Lowell, MA (United States); Khan, F; Crawford, B; Turcotte, J; Sharp, G [Massachusetts General Hospital Boston MA (United States); Mah’D, M [University of Massachusetts Lowell Lowell, MA (United States)

    2016-06-15

    Purpose: To present a 3D QA method and clinical results for 550 patients. Methods: Five hundred and fifty patient treatment deliveries (400 IMRT, 75 SBRT and 75 VMAT) from various treatment sites, planned on Raystation treatment planning system (TPS), were measured on three beam-matched Elekta linear accelerators using IBA’s COMPASS system. The difference between TPS computed and delivered dose was evaluated in 3D by applying three statistical parameters to each structure of interest: absolute average dose difference (AADD, 6% allowed difference), absolute dose difference greater than 6% (ADD6, 4% structure volume allowed to fail) and 3D gamma test (3%/3mm DTA, 4% structure volume allowed to fail). If the allowed value was not met for a given structure, manual review was performed. The review consisted of overlaying dose difference or gamma results with the patient CT, scrolling through the slices. For QA to pass, areas of high dose difference or gamma must be small and not on consecutive slices. For AADD to manually pass QA, the average dose difference in cGy must be less than 50cGy. The QA protocol also includes DVH analysis based on QUANTEC and TG-101 recommended dose constraints. Results: Figures 1–3 show the results for the three parameters per treatment modality. Manual review was performed on 67 deliveries (27 IMRT, 22 SBRT and 18 VMAT), for which all passed QA. Results show that statistical parameter AADD may be overly sensitive for structures receiving low dose, especially for the SBRT deliveries (Fig.1). The TPS computed and measured DVH values were in excellent agreement and with minimum difference. Conclusion: Applying DVH analysis and different statistical parameters to any structure of interest, as part of the 3D QA protocol, provides a comprehensive treatment plan evaluation. Author G. Gueorguiev discloses receiving travel and research funding from IBA for unrelated to this project work. Author B. Crawford discloses receiving travel funding from

  9. Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the hypofractionated treatment of high-risk prostate cancer

    International Nuclear Information System (INIS)

    Yuen, Jasper; Rodrigues, George; Trenka, Kristina; Coad, Terry; Yartsev, Slav; D'Souza, David; Lock, Michael; Bauman, Glenn

    2008-01-01

    To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the setting of hypofractionated high-risk prostate cancer treatment. 3DCRT and dIMRT/Helical Tomotherapy(HT) planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate) and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets) in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes) and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures) were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p < 0.001), similar nodal coverage (8/8 t-test comparisons; p = ns), higher and more homogenous pelvic tissue dose (6/6 t-test comparisons; p < 0.03), at the cost of slightly higher critical structure dose (D dose , 1–3 Gy over 5/10 dose points; p < 0.03). The dIMRT/HT approaches were superior to 3DCRT in sparing organs at risk (22/24 t-test comparisons; p < 0.05). dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies

  10. Congenital intracranial meningioma. A case report and literature review

    DEFF Research Database (Denmark)

    Madsen, C; Schrøder, H D

    1993-01-01

    A case report of congenital intracranial meningioma is presented. We describe what appears to be the first fetal meningioma of the fibroblastic subtype. The literature is reviewed, and the subtype and sex distribution of fetal meningiomas is discussed.......A case report of congenital intracranial meningioma is presented. We describe what appears to be the first fetal meningioma of the fibroblastic subtype. The literature is reviewed, and the subtype and sex distribution of fetal meningiomas is discussed....

  11. Peptide receptor radionuclide therapy with {sup 90}Y-DOTATOC in recurrent meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Bartolomei, Mirco; Bodei, Lisa; De Cicco, Concetta; Grana, Chiara Maria; Baio, Silvia Melania; Arico, Demetrio; Paganelli, Giovanni [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Cremonesi, Marta [European Institute of Oncology, Division of Medical Physics, Milan (Italy); Botteri, Edoardo [European Institute of Oncology, Division of Epidemiology and Biostatistics, Milan (Italy); Sansovini, Maddalena [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (I.R.S.T.), Radiometabolic Medicine Division, Meldola (Italy)

    2009-09-15

    Meningiomas are generally benign and in most cases surgery is curative. However, for high-grade histotypes or partially resected tumours, recurrence is fairly common. External beam radiation therapy (EBRT) is usually given in such cases but is not always effective. We assessed peptide receptor radionuclide therapy (PRRT) using {sup 90}Y-DOTATOC in a group of patients with meningioma recurring after standard treatments in all of whom somatostatin receptors were strongly expressed on meningioma cell surfaces. Twenty-nine patients with scintigraphically proven somatostatin subtype 2 receptor-positive meningiomas were enrolled: 14 had benign (grade I), 9 had atypical (grade II) and 6 had malignant (grade III) disease. Patients received intravenous {sup 90}Y-DOTATOC for 2-6 cycles for a cumulative dose in the range of 5-15 GBq. Clinical and neuroradiological evaluations were performed at baseline, during and after PRRT. The treatment was well tolerated in all patients. MRI 3 months after treatment completion showed disease stabilization in 19 of 29 patients (66%) and progressive disease in the remaining 10 (34%). Better results were obtained in patients with grade I meningioma than in those with grade II-III, with median time to progression (from beginning PRRT) of 61 months in the low-grade group and 13 months in the high-grade group. PRRT with {sup 90}Y-DOTATOC can interfere with the growth of meningiomas. The adjuvant role of this treatment, soon after surgery, especially in atypical and malignant histotypes, deserves further investigation. (orig.)

  12. Radiation-induced meningiomas in pediatric patients

    International Nuclear Information System (INIS)

    Moss, S.D.; Rockswold, G.L.; Chou, S.N.; Yock, D.; Berger, M.S.

    1988-01-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature

  13. Dosimetric comparison of IMRT and modulated arc-therapy techniques in the treatment of cervical cancers; Comparaison dosimetrique des techniques de RCMI et d'arctherapie modulee dans le traitement des cancers du col uterin

    Energy Technology Data Exchange (ETDEWEB)

    Renard-Oldrini, S.; Charra-Brunaud, C.; Tournier-Rangeard, L.; Huger, S.; Marchesi, V.; Bouziz, D.; Peiffert, D. [Centre Alexis-Vautrin, Nancy (France)

    2011-10-15

    The authors report the dosimetric comparison of two techniques used for the treatment of cervical cancers: the intensity-modulated conformational radiotherapy (IMRT) with static beams and modulated arc-therapy with RapidArc. The treatment plans of 15 patients have been compared. The clinical target volume (CTV) comprises the gross target volume, the cervix, the upper third of the vagina, and ganglionary areas. The previsional target volume comprises the clinical target volume and a one centimetre margin. Organs at risk are rectum, bladder, intestine and bone marrow. Arc-therapy seems to provide a better sparing of intestine that IMRT, while maintaining a good coverage of the previsional target volume and decreasing treatment duration. Short communication

  14. Dosimetry tools and techniques for IMRT

    International Nuclear Information System (INIS)

    Low, Daniel A.; Moran, Jean M.; Dempsey, James F.; Dong Lei; Oldham, Mark

    2011-01-01

    Intensity modulated radiation therapy (IMRT) poses a number of challenges for properly measuring commissioning data and quality assurance (QA) radiation dose distributions. This report provides a comprehensive overview of how dosimeters, phantoms, and dose distribution analysis techniques should be used to support the commissioning and quality assurance requirements of an IMRT program. The proper applications of each dosimeter are described along with the limitations of each system. Point detectors, arrays, film, and electronic portal imagers are discussed with respect to their proper use, along with potential applications of 3D dosimetry. Regardless of the IMRT technique utilized, some situations require the use of multiple detectors for the acquisition of accurate commissioning data. The overall goal of this task group report is to provide a document that aids the physicist in the proper selection and use of the dosimetry tools available for IMRT QA and to provide a resource for physicists that describes dosimetry measurement techniques for purposes of IMRT commissioning and measurement-based characterization or verification of IMRT treatment plans. This report is not intended to provide a comprehensive review of commissioning and QA procedures for IMRT. Instead, this report focuses on the aspects of metrology, particularly the practical aspects of measurements that are unique to IMRT. The metrology of IMRT concerns the application of measurement instruments and their suitability, calibration, and quality control of measurements. Each of the dosimetry measurement tools has limitations that need to be considered when incorporating them into a commissioning process or a comprehensive QA program. For example, routine quality assurance procedures require the use of robust field dosimetry systems. These often exhibit limitations with respect to spatial resolution or energy response and need to themselves be commissioned against more established dosimeters. A chain of

  15. An analysis of tolerance levels in IMRT quality assurance procedures

    International Nuclear Information System (INIS)

    Basran, Parminder S.; Woo, Milton K.

    2008-01-01

    Increased use of intensity modulated radiation therapy (IMRT) has resulted in increased efforts in patient quality assurance (QA). Software and detector systems intended to streamline the IMRT quality assurance process often report metrics, such as percent discrepancies between measured and computed doses, which can be compared to benchmark or threshold values. The purpose of this work is to examine the relationships between two different types of IMRT QA processes in order to define, or refine, appropriate tolerances values. For 115 IMRT plans delivered in a 3 month period, we examine the discrepancies between (a) the treatment planning system (TPS) and results from a commercial independent monitor unit (MU) calculation program; (b) TPS and results from a commercial diode-array measurement system; and (c) the independent MU calculation and the diode-array measurements. Statistical tests were performed to assess significance in the IMRT QA results for different disease site and machine models. There is no evidence that the average total dose discrepancy in the monitor unit calculation depends on the disease site. Second, the discrepancies in the two IMRT QA methods are independent: there is no evidence that a better --or worse--monitor unit validation result is related to a better--or worse--diode-array measurement result. Third, there is marginal benefit in repeating the independent MU calculation with a more suitable dose point, if the initial IMRT QA failed a certain tolerance. Based on these findings, the authors conclude at some acceptable tolerances based on disease site and IMRT QA method. Specifically, monitor unit validations are expected to have a total dose discrepancy of 3% overall, and 5% per beam, independent of disease site. Diode array measurements are expected to have a total absolute dose discrepancy of 3% overall, and 3% per beam, independent of disease site. The percent of pixels exceeding a 3% and 3 mm threshold in a gamma analysis should be

  16. Outcome of Elderly Patients with Meningioma after Image-Guided Stereotactic Radiotherapy: A Study of 100 Cases

    Directory of Open Access Journals (Sweden)

    David Kaul

    2015-01-01

    Full Text Available Introduction. Incidence of meningioma increases with age. Surgery has been the mainstay treatment. Elderly patients, however, are at risk of severe morbidity. Therefore, we conducted this study to analyze long-term outcomes of linac-based fractionated stereotactic radiotherapy (FSRT for older adults (aged ≥65 years with meningioma and determine prognostic factors. Materials and Methods. Between October 1998 and March 2009, 100 patients (≥65, median age, 71 years were treated with FSRT for meningioma. Two patients were lost to follow-up. Eight patients each had grade I and grade II meningiomas, and five patients had grade III meningiomas. The histology was unknown in 77 cases (grade 0. Results. The median follow-up was 37 months, and 3-year, 5-year, and 10-year progression-free survival (PFS rates were 93.7%, 91.1%, and 82%. Patients with grade 0/I meningioma showed 3- and 5-year PFS rates of 98.4% and 95.6%. Patients with grade II or III meningiomas showed 3-year PFS rates of 36%. 93.8% of patients showed local tumor control. Multivariate analysis did not indicate any significant prognostic factors. Conclusion. FSRT may play an important role as a noninvasive and safe method in the clinical management of older patients with meningioma.

  17. Set-up errors analyses in IMRT treatments for nasopharyngeal carcinoma to evaluate time trends, PTV and PRV margins

    Energy Technology Data Exchange (ETDEWEB)

    Mongioj, Valeria (Dept. of Medical Physics, Fondazione IRCCS Istituto Nazionale Tumori, Milan (Italy)), e-mail: valeria.mongioj@istitutotumori.mi.it; Orlandi, Ester (Dept. of Radiotherapy, Fondazione IRCCS Istituto Nazionale Tumori, Milan (Italy)); Palazzi, Mauro (Dept. of Radiotherapy, A.O. Niguarda Ca' Granda, Milan (Italy)) (and others)

    2011-01-15

    Introduction. The aims of this study were to analyze the systematic and random interfractional set-up errors during Intensity Modulated Radiation Therapy (IMRT) in 20 consecutive nasopharyngeal carcinoma (NPC) patients by means of Electronic Portal Images Device (EPID), to define appropriate Planning Target Volume (PTV) and Planning Risk Volume (PRV) margins, as well as to investigate set-up displacement trend as a function of time during fractionated RT course. Material and methods. Before EPID clinical implementation, an anthropomorphic phantom was shifted intentionally 5 mm to all directions and the EPIs were compared with the digitally reconstructed radiographs (DRRs) to test the system's capability to recognize displacements observed in clinical studies. Then, 578 clinical images were analyzed with a mean of 29 images for each patient. Results. Phantom data showed that the system was able to correct shifts with an accuracy of 1 mm. As regards clinical data, the estimated population systematic errors were 1.3 mm for left-right (L-R), 1 mm for superior-inferior (S-I) and 1.1 mm for anterior-posterior (A-P) directions, respectively. Population random errors were 1.3 mm, 1.5 mm and 1.3 mm for L-R, S-I and A-P directions, respectively. PTV margin was at least 3.4, 3 and 3.2 mm for L-R, S-I and A-P direction, respectively. PRV margins for brainstem and spinal cord were 2.3, 2 and 2.1 mm and 3.8, 3.5 and 3.2 mm for L-R, A-P and S-I directions, respectively. Set-up error displacements showed no significant changes as the therapy progressed (p>0.05), although displacements >3 mm were found more frequently when severe weight loss or tumor nodal shrinkage occurred. Discussion. These results enable us to choose margins that guarantee with sufficient accuracy the coverage of PTVs and organs at risk sparing. Collected data confirmed the need for a strict check of patient position reproducibility in case of anatomical changes

  18. Surgical outcomes after reoperation for recurrent skull base meningiomas.

    Science.gov (United States)

    Magill, Stephen T; Lee, David S; Yen, Adam J; Lucas, Calixto-Hope G; Raleigh, David R; Aghi, Manish K; Theodosopoulos, Philip V; McDermott, Michael W

    2018-05-04

    OBJECTIVE Skull base meningiomas are surgically challenging tumors due to the intricate skull base anatomy and the proximity of cranial nerves and critical cerebral vasculature. Many studies have reported outcomes after primary resection of skull base meningiomas; however, little is known about outcomes after reoperation for recurrent skull base meningiomas. Since reoperation is one treatment option for patients with recurrent meningioma, the authors sought to define the risk profile for reoperation of skull base meningiomas. METHODS A retrospective review of 2120 patients who underwent resection of meningiomas between 1985 and 2016 was conducted. Clinical information was extracted from the medical records, radiology data, and pathology data. All records of patients with recurrent skull base meningiomas were reviewed. Demographic data, presenting symptoms, surgical management, outcomes, and complications data were collected. Kaplan-Meier analysis was used to evaluate survival after reoperation. Logistic regression was used to evaluate for risk factors associated with complications. RESULTS Seventy-eight patients underwent 100 reoperations for recurrent skull base meningiomas. Seventeen patients had 2 reoperations, 3 had 3 reoperations, and 2 had 4 or more reoperations. The median age at diagnosis was 52 years, and 64% of patients were female. The median follow-up was 8.5 years. Presenting symptoms included cranial neuropathy, headache, seizure, proptosis, and weakness. The median time from initial resection to first reoperation was 4.4 years and 4.1 years from first to second reoperation. Seventy-two percent of tumors were WHO grade I, 22% were WHO grade II, and 6% were WHO grade III. The sphenoid wing was the most common location (31%), followed by cerebellopontine angle (14%), cavernous sinus (13%), olfactory groove (12%), tuberculum sellae (12%), and middle fossa floor (5%). Forty-four (54%) tumors were ≥ 3 cm in maximum diameter at the time of the first

  19. The results of radiation therapy for intracranial meningiomas. With special reference to the natural course of the tumor size after radiotherapy

    International Nuclear Information System (INIS)

    Kobayashi, Katsuhiro; Murakami, Masao; Kubo, Takeshi; Kono, Koichi; Okamoto, Yoshiaki; Kuroda, Yasumasa

    1998-01-01

    Twenty-four cases with intracranial meningioma received radiation therapy from 1967 to 1995 at Tenri Hospital. Two received preoperative radiotherapy and 22 post operative radiotherapy. Of all, 11 were benign, 9 were malignant and 4 were reported only as meningioma. The extent of surgery consisted of total resection in 4, subtotal resection in 10, partial resection in 6, biopsy in 2, exploration in 1 and unknown in 1. Twelve were initial treatments and another 12 were salvage treatments. In all cases, radiation therapy was given a mean dose of 53.6 Gy with 6 or 10 MV X-rays using conventional fractionation. The mean follow-up interval is 56.7 months. Total cause specific survival at 5 and 10 years were 79% and 69%, respectively. The 10-year recurrence-free survival was 100% in benign and 61% in malignant meningiomas. The clinical course of benign meningiomas suggested the value of postoperative radiation therapy, but that of malignant meningiomas were divided into 2 groups, in which some one had recurrence just after completion of radiotherapy or another had local control. It seemed that there were some radio-resistant varieties in malignant meningiomas. The result of the consecutive follow-up by enhanced CT or MRI revealed benign meningiomas had a tendency to decrease in size in a long interval and some malignant meningiomas changed their size soon after radiotherapy. From analysis of our study we conclude that radiation therapy is a useful post-surgical treatment for intracranial meningiomas. (author)

  20. Hybrid IMRT plans-concurrently treating conventional and IMRT beams for improved breast irradiation and reduced planning time

    International Nuclear Information System (INIS)

    Mayo, Charles S.; Urie, Marcia M.; Fitzgerald, Thomas J.

    2005-01-01

    Purpose: To evaluate a hybrid intensity modulated radiation therapy (IMRT) technique as a class solution for treatment of the intact breast. Methods and materials: The following five plan techniques were compared for 10 breast patients using dose-volume histogram analysis: conventional wedged-field tangents (Tangents), forward-planned field-within-a-field tangents (FIF), IMRT-only tangents (IMRT tangents), conventional open plus IMRT tangents (4-field hybrid), and conventional open plus IMRT tangents with 2 anterior oblique IMRT beams (6-field hybrid). Results: The 4-field hybrid and FIF achieved dose distributions better than Tangents and IMRT tangents. The volume of tissue outside the planning target volume receiving ≥110% of prescribed dose was largest for IMRT tangents (average 158 cc) and least for 6-field hybrid (average 1 cc); the FIF and 4-field hybrid were comparable (average 15 cc). Heart volume ≥30 Gy averaged 13 cc for all techniques, except Tangents, for which it was 32 cc. Average total lung volume ≥20 Gy was 7% for all. Contralateral breast doses were < 3% for all. Planning time for hybrid techniques was significantly less than for conventional FIF technique. Conclusions: The 4-field hybrid technique is a viable class solution. The 6-field hybrid technique creates the most conformal dose distribution at the expense of more normal tissue receiving low dose

  1. Edema and malignancy in meningiomas

    OpenAIRE

    Mattei,Tobias Alécio; Mattei,Josias Alécio; Ramina,Ricardo; Aguiar,Paulo Henrique; Plese,José Pindaro; Marino Jr,Raul

    2005-01-01

    PURPOSE: In recent years there have been many attempts to define a subset of aggressive malignant meningiomas based on histopathology and imaging technologies. The purpose of this study was to evaluate the level of peritumoral edema and its volume using the imaging technologies, computer tomography and magnetic resonance imaging, and correlate these results with the histological WHO classification. Reported causes of tumoral edema and its relationships to the histological characteristics were...

  2. Postoperative radiotherapy for intracranial meningioma

    International Nuclear Information System (INIS)

    Chun, Ha Chung; Lee, Myung Za

    2001-01-01

    To evaluate the effectiveness and tolerance of postoperative external radiotherapy for patients with intracranial meningiomas. The records of thirty three patients with intracranial meningiomas who were treated with postoperative external irradiation at our institution between Feb, 1988 and Nov, 1999 were retrospectively analyzed. Median age of patients at diagnosis was 53 years with range of 17 to 68 years. Sites of involvement were parasagital, cerebral convexity, sphenoid ridge, parasellar and tentorium cerebella. Of 33 evaluated patients, 15 transitional, 10 meningotheliomatous, 4 hemangiopericytic, 3 atypical and 1 malignant meningioma were identified. Four patients underwent biopsy alone and remaining 29 patients underwent total tumor resection. A dose of 50 to 60 Gy was delivered in 28-35 daily fractions over a period of 5 to 7 weeks. Follow-up period ranged from 12 months to 8 years. The actuarial survival rates at 5 and 7 years for entire group of patients were 78% and 67%, respectively. The corresponding disease free survival rates were 73% and 61 %, respectively. The overall local control rate at 5 years was 83%. One out of 25 patients in benign group developed local failure, while 4 out of 8 patients in malignant group did local failure (p <0.05), Of 4 patients who underwent biopsy alone, 2 developed local failure. There was no significant difference in 5 year actuarial survival between patients who underwent total tumor resection and those who did biopsy alone. Patients whose age is under 60 showed slightly better survival than those whose age is 60 or older, although this was not statistically significant. There was no documented late complications in any patients. Based on our study, we might conclude that postoperative external beam radiotherapy tends to improve survival of patients with intracranial meningiomas comparing with surgery alone

  3. Nephrotic syndrome associated with meningioma

    Directory of Open Access Journals (Sweden)

    P P Zachariah

    2013-01-01

    Full Text Available A 58-year-old man presented with recurrent frontal meningioma and nephrotic syndrome. Renal biopsy could not be done in view of the rapid neurological deterioration. The patient underwent surgical resection of the tumor. Within 4 weeks, the edema decreased, serum albumin improved, and proteinuria decreased spontaneously. At three months of followup, the patient had attained complete remission of nephrotic state.

  4. Meningiomas of pineal region in children Meningiomas da região da pineal em crianças

    Directory of Open Access Journals (Sweden)

    Hamilton Matushita

    2007-12-01

    Full Text Available Meningiomas are uncommon tumors in children and either more rarely encountered in the pineal region. We report two cases of meningioma of the pineal region in children. One of these cases was a five years-old girl and the other a one year-old boy. No specific clinical presentation or tomographic examinations findings was identified before treatment, suggestive of a diagnosis of menigioma. The clinical and laboratory features were very similar to the most common tumors of the pineal region. Prior to the surgery, the histology of these tumors was not suspected. Both patients underwent direct surgery and complete removal was achieved by a suboccipital transtentorial approach. The tumors originated from velum interpositum in both cases. At the follow up, one case presented with recurrence six years later, and she underwent a reoperation with total resection without morbidity. Long-term follow up presented no other recurrences.Meningiomas são tumores poucos frequentes em crianças, e mais raramente encontrados na região da pineal. Relatamos dois casos de meningioma da região da pineal em crianças, uma menina de cinco anos e um menino de um ano de idade. Não foi identificada nenhuma forma de apresentação clinica ou caracteristica tomográfica, antes do tratamento, que sugerisse o diagnóstico de meningioma. As características clinicas e laboratoriais encontradas foram similares às de tumores mais frequentes da região da pineal. Ambos os pacientes foram submetidos ao tratamento cirúrgico e a remoção completa foi obtida por abordagem suboccipital transtentorial. Durante o seguimento, um dos pacientes foi reoperado por recorrencia do tumor seis anos após o tratamento inicial. Atualmente, os pacientes encontram-se livres de recorrência tumoral.

  5. A case of hypervascular meningioma

    International Nuclear Information System (INIS)

    Takahashi, Jun; Makita, Yasumasa; Nabeshima, Sachio; Tei, Taikyoku; Keyaki, Atsushi; Miyamoto, Yoshihisa

    1988-01-01

    A 30-year-old, right handed male was admitted with headache and mild right-sided motor weakness of one year's duration. A CT scan revealed a mass over the left frontal convexity. A cerebral angiogram showed a huge, hypervascular tumor which was fed by bilateral external carotid and left internal carotid arteries. Because of its size and location, a surgical intervention was considered contraindicated at that time. Instead he was initially irradiated 52 Gy in total dose with 10 MV x-rays (Lineac). A CT scan 4 month thereafter revealed remarkable decrease in the size of tumor and reduction of its mass effect. A CT scan 12 months later, however, revealed increase in low density area around mass, although the size of the tumor was much smaller than before. He was readmitted for surgery 14 months after irradiation. An angiogram visualized more reduction of tumor stain and the caliber of feeding arteries. The tumor was totally removed without resultant neurological deficits. A histological diagnosis of the tumor was meningotheliomatous meningioma with well developed vascular networks. Meningioma is usually not a radiosensitive tumor, but there are some reports of cases with hypervascular meningiomas which have been effectively treated with irradiation preoperatively. In the present case, because of a huge vascular tumor in the dominant hemisphere, irradiation was given initial and 14 months thereafter the tumor was totally removed without neurological deficits. (author)

  6. Effect of various methods for rectum delineation on relative and absolute dose-volume histograms for prostate IMRT treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Kusumoto, Chiaki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ohira, Shingo [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita (Japan); Miyazaki, Masayoshi [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ueda, Yoshihiro [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Radiation Oncology, Graduate School of Medicine, Osaka University, Suita (Japan); Isono, Masaru [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Teshima, Teruki, E-mail: teshima-te@mc.pref.osaka.jp [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan)

    2016-07-01

    Several reports have dealt with correlations of late rectal toxicity with rectal dose-volume histograms (DVHs) for high dose levels. There are 2 techniques to assess rectal volume for reception of a specific dose: relative-DVH (R-DVH, %) that indicates relative volume for a vertical axis, and absolute-DVH (A-DVH, cc) with its vertical axis showing absolute volume of the rectum. The parameters of DVH vary depending on the rectum delineation method, but the literature does not present any standardization of such methods. The aim of the present study was to evaluate the effects of different delineation methods on rectal DVHs. The enrollment for this study comprised 28 patients with high-risk localized prostate cancer, who had undergone intensity-modulated radiation therapy (IMRT) with the prescription dose of 78 Gy. The rectum was contoured with 4 different methods using 2 lengths, short (Sh) and long (Lg), and 2 cross sections, rectum (Rec) and rectal wall (Rw). Sh means the length from 1 cm above the seminal vesicles to 1 cm below the prostate and Lg the length from the rectosigmoid junction to the anus. Rec represents the entire rectal volume including the rectal contents and Rw the rectal volume of the area with a wall thickness of 4 mm. We compared dose-volume parameters by using 4 rectal contour methods for the same plan with the R-DVHs as well as the A-DVHs. For the high dose levels, the R-DVH parameters varied widely. The mean of V{sub 70} for Sh-Rw was the highest (19.4%) and nearly twice as high as that for Lg-Rec (10.4%). On the contrary, only small variations were observed in the A-DVH parameters (4.3, 4.3, 5.5, and 5.5 cc for Sh-Rw, Lg-Rw, Sh-Rec, and Lg-Rec, respectively). As for R-DVHs, the parameters of V{sub 70} varied depending on the rectal lengths (Sh-Rec vs Lg-Rec: R = 0.76; Sh-Rw vs Lg-Rw: R = 0.85) and cross sections (Sh-Rec vs Sh-Rw: R = 0.49; Lg-Rec vs Lg-Rw: R = 0.65). For A-DVHs, however, the parameters of Sh rectal A-DVHs hardly changed

  7. The Treatment Outcome and Radiation-Induced Toxicity for Patients with Head and Neck Carcinoma in the IMRT Era: A Systematic Review with Dosimetric and Clinical Parameters

    Directory of Open Access Journals (Sweden)

    Vassilis Kouloulias

    2013-01-01

    Full Text Available A descriptive analysis was made in terms of the related radiation induced acute and late mucositis and xerostomia along with survival and tumor control rates (significance level at 0.016, bonferroni correction, for irradiation in head and neck carcinomas with either 2D Radiation Therapy (2DRT and 3D conformal (3DCRT or Intensity Modulated Radiation Therapy (IMRT. The mean score of grade > II xerostomia for IMRT versus 2-3D RT was 0.31 ± 0.23 and 0.56 ± 0.23, respectively (Mann Whitney, P<0.001. The parotid-dose for IMRT versus 2-3D RT was 29.56 ± 5.45 and 50.73 ± 6.79, respectively (Mann Whitney, P=0.016. The reported mean parotid-gland doses were significantly correlated with late xerostomia (spearman test, rho = 0.5013, P<0.001. A trend was noted for the superiority of IMRT concerning the acute oral mucositis. The 3-year overall survival for either IMRT or 2-3DRT was 89.5% and 82.7%, respectively (P=0.026, Kruskal-Wallis test. The mean 3-year locoregional control rate was 83.6% (range: 70–97% and 74.4 (range: 61–82%, respectively (P=0.025, Kruskal-Wallis. In conclusion, no significant differences in terms of locoregional control, overall survival and acute mucositis could be noted, while late xerostomia is definitely higher in 2-3D RT versus IMRT. Patients with head and neck carcinoma should be referred preferably to IMRT techniques.

  8. Radiotherapy for intracranial meningioma. Special reference to malignant and high risk benign meningioma

    International Nuclear Information System (INIS)

    Shimizu, Teppei; Iijima, Mitsuharu; Tanaka, Yoshiaki

    1995-01-01

    Results of radiotherapy in 21 patients who had been treated for intracranial meningioma from April 1975 to March 1993 at Tokyo Metropolitan Komagome Hospital are presented. All patients were treated with 4 MV X-rays using conventional fractionation. The median tumor dose was 54.4 Gy (range 30 Gy to 70 Gy). Radiotherapy was delivered by conformation technique in 11, parallel opposed field in four and three ports technique in two. Of 21 meningiomas, 13 were histologically malignant and 8 were benign. The median follow-up period was 63 months. Overall survival rate at 5 years was 71% for benign and 63% for malignant meningiomas; the 5-year progression-free survival rates were 25% and 30%, respectively. Eight of 21 patients received 60 Gy or more, and the remaining 13 received less than 60 Gy. The 5-year overall survival rates for these two groups were 43% and 83% (p<0.05), respectively. Ten of 21 patients were treated with post-operative radiotherapy as initial treatment and eleven of 21 patients were treated with salvage therapy with or without surgical excision for recurrent lesions. The 5-year survival rates and progression-free survival rates of these two groups showed no significant differences. From analysis of the clinical course of the salvage therapy group, radiotherapy may prolong survival time and delay further tumor recurrence. According to the present study, radiotherapy (doses of 55 Gy to 60 Gy) after primary resection and at the time of recurrence are equally effective for prolongation of survival and delay of further tumor recurrence. (author)

  9. IMRT and radiation protection in the prostate cancer therapy

    International Nuclear Information System (INIS)

    Santos, Helena C.; Silva, Andre R.M.; Oliveira, Claudia F.M.

    2015-01-01

    This study aims to specify the technological advances that IMRT presents relative to other traditional radiotherapy, particularly to conformal radiotherapy three dimensional (3D-TCR) and benefits compared to the side effects caused by from treatment of radiotherapy

  10. Prostate Dose Escalation by Innovative Inverse Planning-Driven IMRT

    National Research Council Canada - National Science Library

    Xing, Lei

    2005-01-01

    .... Because of the tacit ignorance of intra-structural tradeoff, the IMRT plans generated by these systems for prostate treatment are, at best, sub-optimal and our endeavor of providing the best possible...

  11. Use of a Conventional Low Neck Field (LNF) and Intensity-Modulated Radiotherapy (IMRT): No Clinical Detriment of IMRT to an Anterior LNF During the Treatment of Head-and Neck-Cancer

    International Nuclear Information System (INIS)

    Turaka, Aruna; Li Tianyu; Nicolaou, Nicos; Lango, Miriam N.; Burtness, Barbara; Horwitz, Eric M.; Ridge, John A.; Feigenberg, Steven J.

    2011-01-01

    Purpose: To determine differences in clinical outcomes using intensity-modulated radiotherapy (IMRT) or a standard low neck field (LNF) to treat low neck. Methods and Materials: This is a retrospective, single-institution study. Ninety-one patients with squamous cell carcinoma of the head and neck were treated with curative intent. According to physician preference, some patients were treated with LNF (Planning Target Volume 3) field using a single anterior photon field matched to the IMRT field. Field junctions were not feathered. The endpoints were time to failure and use of a percutaneous endoscopic gastrostomy (PEG) tube (as a surrogate of laryngeal edema causing aspiration), and analysis was done with χ 2 and log-rank tests. Results: Median follow-up was 21 months (range, 2-89 months). Median age was 60 years. Thirty-seven patients (41%) were treated with LNF, 84% were Stage III or IV. A PEG tube was required in 30%, as opposed to 33% without the use of LNF. Node 2 or 3 neck disease was treated more commonly without LNF (38% vs. 24%, p = 0.009). Failures occurred in 12 patients (13%). Only 1 patient treated with LNF failed regionally, 4.5 cm above the match line. The 3-year disease-free survival rate was 87% and 79% with LNF and without LNF, respectively (p = 0.2), and the 3-year LR failure rate was 4% and 21%, respectively (p = 0.04). Conclusions: Using LNF to treat the low neck did not increase the risk of regional failure 'in early T and early N diseases' or decrease PEG tube requirements.

  12. Dosimetric verification of IMRT plans

    International Nuclear Information System (INIS)

    Bulski, W.; Cheimicski, K.; Rostkowska, J.

    2012-01-01

    Intensity modulated radiotherapy (IMRT) is a complex procedure requiring proper dosimetric verification. IMRT dose distributions are characterized by steep dose gradients which enable to spare organs at risk and allow for an escalation of the dose to the tumor. They require large number of radiation beams (sometimes over 10). The fluence measurements for individual beams are not sufficient for evaluation of the total dose distribution and to assure patient safety. The methods used at the Centre of Oncology in Warsaw are presented. In order to measure dose distributions in various cross-sections the film dosimeters were used (radiographic Kodak EDR2 films and radiochromic Gafchromic EBT films). The film characteristics were carefully examined. Several types of tissue equivalent phantoms were developed. A methodology of comparing measured dose distributions against the distributions calculated by treatment planning systems (TPS) was developed and tested. The tolerance level for this comparison was set at 3% difference in dose and 3 mm in distance to agreement. The so called gamma formalism was used. The results of these comparisons for a group of over 600 patients are presented. Agreement was found in 87 % of cases. This film dosimetry methodology was used as a benchmark to test and validate the performance of commercially available 2D and 3D matrices of detectors (ionization chambers or diodes). The results of these validations are also presented. (authors)

  13. Pure intrasellar meningioma located under the pituitary gland: Case report

    International Nuclear Information System (INIS)

    Cha, Seung Woo; Park, Dong Woo; Park, Choong Ki; Pyo, Ju Yeon; Lee, Young Jun; Lee, SAeung Ro

    2013-01-01

    Most intrasellar meningiomas are located in the subdiaphragmatic and supraglandular region because they originate from the diaphragma sellae. Subglandular meningiomas located under the pituitary gland are extremely rare. Intrasellar meningiomas in the subdiaphragmatic and subglandular region probably originate from the dura in the sellar floor. We report a case of a subglandular meningioma along with a review of the literature.

  14. Pure intrasellar meningioma located under the pituitary gland: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seung Woo; Park, Dong Woo; Park, Choong Ki; Pyo, Ju Yeon [College of Medicine, Hanyang University, Guri Hospital, Guri (Korea, Republic of); Lee, Young Jun; Lee, SAeung Ro [Dept. of Radiology, College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2013-04-15

    Most intrasellar meningiomas are located in the subdiaphragmatic and supraglandular region because they originate from the diaphragma sellae. Subglandular meningiomas located under the pituitary gland are extremely rare. Intrasellar meningiomas in the subdiaphragmatic and subglandular region probably originate from the dura in the sellar floor. We report a case of a subglandular meningioma along with a review of the literature.

  15. Clinical results of BNCT for malignant meningiomas

    International Nuclear Information System (INIS)

    Miyatake, Shin-ichi; Tamura, Yoji; Kawabata, Shinji

    2006-01-01

    Malignant meningiomas is difficult pathology to be controlled as well as GBM. Since June of 2005, we applied BNCT for 7 cases of malignancy related meningiomas with 13 times neutron irradiation. Five were anaplastic, one was atypical meningiomas and one was sarcoma transformed from meningioma with cervical lymph node metastasis. All cases were introduced after repetitive surgeries and XRT or SRS. Follow-up images were available for 6 cases with observation duration between 2 to 9 months. We applied F-BPA-PET before BNCT in 6 out of 7 cases. One case was received methionine-PET. Five out of 6 cases who received BPA-PET study showed good BPA uptake more than 3 of T/N ratio. One atypical meningiomas cases showed 2.0 of T/N ratio. Original tumor sizes were between 9.2 to 92.7 ml. Two out of 5 anaplastic meningiomas showed CR and all six cases showed radiographic improvements. Clinical symptoms before BNCT such as hemiparesis and facial pain were improved after BNCT, except one case. An huge atypical meningiomas which arisen from tentorium and extended bilateral occipital lobes and brain stem, visual problems were worsened after repetitive BNCT with increase of peritumoral edema. Malignant meningiomas are seemed to be good candidate for BNCT. (author)

  16. Intracranial meningiomas after high-dose irradiation

    International Nuclear Information System (INIS)

    Soffer, D.; Gomori, J.M.; Siegal, T.; Shalit, M.N.

    1989-01-01

    Three patients who presented with intracranial meningiomas 12, 15, and 20 years, respectively, after therapeutic high-dose irradiation of a primary brain tumor are described. Analysis of these cases and similar documented cases suggests that meningiomas after high-dose irradiation constitute a recognizable entity. Patients with such tumors received radiation therapy at a young age (mean age, 9.4 years). After a latent period of 2 to 47 years (mean, 19.8 years) they developed meningiomas at the site of irradiation, at a much younger age than patients with ''spontaneous'' meningiomas. Similar to the situation with meningiomas after low-dose irradiation, a relatively high proportion of meningiomas induced by high-dose irradiation tend to be malignant and biologically aggressive. A very young age at the time of irradiation seems to predispose to the induction of malignant meningiomas, rather than benign tumors. These unusual features provide indirect evidence that high-dose radiation may play a role in the pathogenesis of meningiomas.41 references

  17. Magnetic resonance imaging of xanthomatous meningioma

    International Nuclear Information System (INIS)

    Katayama, Y.; Tsubokawa, T.; Tanaka, A.; Koshinaga, M.; Nemoto, N.

    1993-01-01

    A case of meningioma with extensive xanthomatous metaplasia occurring in the left frontal convexity of a 37-year-old woman is reported. The tumour was demonstrated as a hypodense mass with minimal enhancement on CT. Our findings suggest that magnetic resonance imaging may provide a clue to the diagnosis of meningiomas with extensive xanthomatous metaplasia when CT is less specific. (orig.)

  18. Peritumoral brain edema in angiomatous supratentorial meningiomas

    DEFF Research Database (Denmark)

    Nassehi, Damoun; Sørensen, Lars Peter; Dyrbye, Henrik

    2013-01-01

    The aim of this work was to study the vascular endothelial growth factor A (VEGF-A) pathway and peritumoral brain edema (PTBE) through comparison of non-angiomatous and angiomatous meningiomas. Meningiomas are common intracranial tumors, which often have PTBE. VEGF-A is an integral part of PTBE...

  19. Intensity modulated radiotherapy (IMRT) with compensators

    International Nuclear Information System (INIS)

    Salz, H.; Wiezorek, T.; Scheithauer, M.; Kleen, W.; Schwedas, M.; Wendt, T.G.

    2002-01-01

    The irradiation with intensity-modulated fields is possible with static as well as dynamic methods. In our university hospital, the intensity-modulated radiotherapy (IMRT) with compensators was prepared and used for the first time for patient irradiation in July 2001. The compensators consist of a mixture of tin granulate and wax, which is filled in a milled negative mould. The treatment planning is performed with Helax-TMS (MDS Nordion). An additional software is used for editing the modulation matrix ('Modifix'). Before irradiation of the first patient, extensive measurements have been carried out in terms of quality assurance of treatment planning and production of compensators. The results of the verification measurements have shown that IMRT with compensators possesses high spatial and dosimetric exactness. The calculated dose distributions are applied correctly. The accuracy of the calculated monitor units is normally better than 3%; in small volumes, further dosimetric inaccuracies between calculated and measured dose distributions are mostly less than 3%. Therefore, the compensators contribute to the achievement of high-level IMRT even when apparatuses without MLC are used. This paper describes the use of the IMRT with compensators, presents the limits of this technology, and discusses the first practical experiences. (orig.) [de

  20. SU-G-BRC-02: A Novel Multi-Criteria Optimization Approach to Generate Deliverable Intensity-Modulated Radiation Therapy (IMRT) Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Kirlik, G; D’Souza, W; Zhang, H [University of Maryland School of Medicine, Baltimore, MD (United States)

    2016-06-15

    Purpose: To present a novel multi-criteria optimization (MCO) solution approach that generates treatment plans with deliverable apertures using column generation. Methods: We demonstrate our method with 10 locally advanced head-and-neck cancer cases retrospectively. In our MCO formulation, we defined an objective function for each structure in the treatment volume. This resulted in 9 objective functions, including 3 distinct objectives for primary target volume, high-risk and low-risk target volumes, 5 objectives for each of the organs-at-risk (OARs) (two parotid glands, spinal cord, brain stem and oral cavity), and one for the non-target non-OAR normal tissue. Conditional value-at-risk (CVaR) constraints were utilized to ensure at least certain fraction of the target volumes receiving the prescription doses. To directly generate deliverable plans, column generation algorithm was embedded within our MCO approach for aperture shape generation. Final dose distributions for all plans were generated using a Monte Carlo kernel-superposition dose calculation. We compared the MCO plans with the clinical plans, which were created by clinicians. Results: At least 95% target coverage was achieved by both MCO plans and clinical plans. However, the average conformity indices of clinical plans and the MCO plans were 1.95 and 1.35, respectively (31% reduction, p<0.01). Compared to the conventional clinical plan, the proposed MCO method achieved average reductions in left parotid mean dose of 5% (p=0.06), right parotid mean dose of 18% (p<0.01), oral cavity mean dose of 21% (p=0.03), spinal cord maximum dose of 20% (p<0.01), brain stem maximum dose of 61% (p<0.01), and normal tissue maximum dose of 5% (p<0.01), respectively. Conclusion: We demonstrated that the proposed MCO method was able to obtain deliverable IMRT treatment plans while achieving significant improvements in dosimetric plan quality.

  1. IMRT treatment plans and functional planning with functional lung imaging from 4D-CT for thoracic cancer patients

    Directory of Open Access Journals (Sweden)

    Huang Tzung-Chi

    2013-01-01

    Full Text Available Abstract Background and purpose Currently, the inhomogeneity of the pulmonary function is not considered when treatment plans are generated in thoracic cancer radiotherapy. This study evaluates the dose of treatment plans on highly-functional volumes and performs functional treatment planning by incorporation of ventilation data from 4D-CT. Materials and methods Eleven patients were included in this retrospective study. Ventilation was calculated using 4D-CT. Two treatment plans were generated for each case, the first one without the incorporation of the ventilation and the second with it. The dose of the first plans was overlapped with the ventilation and analyzed. Highly-functional regions were avoided in the second treatment plans. Results For small targets in the first plans (PTV  Conclusion Radiation treatments affect functional lung more seriously in large tumor cases. With compromise of dose to other critical organs, functional treatment planning to reduce dose in highly-functional lung volumes can be achieved

  2. Parapharyngeal meningioma extending from the intracranial space

    International Nuclear Information System (INIS)

    Uchibori, M.; Odake, G.; Ueda, S.; Yasuda, N.; Hisa, I.

    1990-01-01

    A 50-year old woman with a giant parapharyngeal meningioma extending from the intracranial cavity was admitted to our hospital. The parapharyngeal tumor was biopsied using the transoral approach, and a histological section diagnosis suggested meningioma. Thereafter, further examination by magnetic resonance images (MRI) and contrast enhanced CT scans revealed a diffuse meningioma en plaque in the posterior fossa. Invasion extended from the clival dura to the right sigmoid sinus. The extracranial extension of a meningioma is very rare but a few cases have been reported. In almost all of the reported cases, a large intracranial meningioma was simultaneously or previously verified by CT scans. Our case was special in that the intracranial mass was not voluminous but showed en plaque extension, and also because the pathway of the extracranial extension through the jugular foramen was clearly visualized by CT and MRI. Obliteration and invasion of the right sigmoid sinus and the internal jugular vein by tumor were also demonstrated. (orig.)

  3. IMRT and radiation protection in the prostate cancer therapy; IMRT e a protecao radiologica no tratamento do cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Helena C.; Silva, Andre R.M.; Oliveira, Claudia F.M., E-mail: andrerichard88@bol.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil)

    2015-07-01

    This study aims to specify the technological advances that IMRT presents relative to other traditional radiotherapy, particularly to conformal radiotherapy three dimensional (3D-TCR) and benefits compared to the side effects caused by from treatment of radiotherapy.

  4. Tuberculum sellae meningiomas: surgical considerations Meningiomas do tuberculo selar: aspectos cirúrgicos

    Directory of Open Access Journals (Sweden)

    José Alberto Landeiro

    2010-06-01

    Full Text Available We report our experience on the treatment of tuberculum sellae meningiomas (TSMs regarding the involvement of the optic canal and clinical outcomes. We reviewed 23 patients who were operated on between January 1997 and December 2008. The surgical approach was unilateral subfrontal supraorbital osteotomy in one piece. Attempts were made to improve visual function via extra/intradural unroofing of the optic canal, which released the optic nerve. Visual symptoms were present preoperatively in 21 patients, and two patients were asymptomatic. Visual acuity remained intact in 6 patients, improved in 10, was unchanged in 5 patients, and worsened in 2 patients. The postoperative visual field was normal or improved in 17 patients, unchanged in four patients, and worsened in two patients. The optic canal and clinoid were drilled extradurally in eight patients and intradurally in nine patients. Total resection of TSMs was achieved in 19 patients. Incomplete resection occurred in two patients. Decompression of the optic canal seemed to increase the visual outcome.Apresentamos nossa experiência em 23 pacientes operados com meningiomas do tubérculo da sela, com enfoque na descompressão do nervo óptico e nos sintomas visuais do pós-operatório. Vinte e três pacientes com meningiomas do tubérculo da sela foram operados entre janeiro de 1997 e dezembro de 2008, através do acesso subfrontal via ostetomia supraorbital. Remoção do teto do canal óptico por via extra ou intradural foi realizada em 17 pacientes. Sintomas visuais no pré-operatório ocorreram em 21 pacientes, 2 eram assintomáticos. Melhora visual ocorreu em 10, permaneceu inalterada em 5 e piorou em 2 pacientes. No pós-operatório o campo visual normalizou-se em 17 pacientes, permaneceu inalterado em 4 e diminuiu em 2. Descompressão dos nervos ópticos foi realizada em 17 pacientes. Ressecção total dos meningiomas do tubérculo da sela foi possível em 19 pacientes. Abertura do canal

  5. IMRT for Image-Guided Single Vocal Cord Irradiation

    International Nuclear Information System (INIS)

    Osman, Sarah O.S.; Astreinidou, Eleftheria; Boer, Hans C.J. de; Keskin-Cambay, Fatma; Breedveld, Sebastiaan; Voet, Peter; Al-Mamgani, Abrahim; Heijmen, Ben J.M.; Levendag, Peter C.

    2012-01-01

    Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose ± standard deviation to the planning target volume was 67 ± 1 Gy. The contralateral vocal cord dose was reduced from 66 ± 1 Gy in the conventional plans to 39 ± 8 Gy and 36 ± 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

  6. IMRT for Image-Guided Single Vocal Cord Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Sarah O.S., E-mail: s.osman@erasmusmc.nl [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Astreinidou, Eleftheria; Boer, Hans C.J. de; Keskin-Cambay, Fatma; Breedveld, Sebastiaan; Voet, Peter; Al-Mamgani, Abrahim; Heijmen, Ben J.M.; Levendag, Peter C. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2012-02-01

    Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose {+-} standard deviation to the planning target volume was 67 {+-} 1 Gy. The contralateral vocal cord dose was reduced from 66 {+-} 1 Gy in the conventional plans to 39 {+-} 8 Gy and 36 {+-} 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

  7. Management of Benign Skull Base Meningiomas: A Review

    OpenAIRE

    Mendenhall, William M.; Friedman, William A.; Amdur, Robert J.; Foote, Kelly D.

    2004-01-01

    The optimal management of benign meningiomas of the skull base is reviewed. Elderly patients with small, asymptomatic tumors can be observed and treatment can be initiated if and when progression occurs. Patients with tumors that appear to be amenable to complete resection with an acceptable rate of morbidity are optimally treated with surgery. Decompression of more extensive tumors through conservative subtotal resection and preservation of the involved cranial nerves may result in improved ...

  8. IMRT fluence map editing to control hot and cold spots

    International Nuclear Information System (INIS)

    Taylor Cook, J.; Tobler, Matt; Leavitt, Dennis D.; Watson, Gordon

    2005-01-01

    Manually editing intensity-modulated radiation therapy (IMRT) fluence maps effectively controls hot and cold spots that the IMRT optimization cannot control. Many times, re-optimizing does not reduce the hot spots or increase the cold spots. In fact, re-optimizing only places the hot and cold spots in different locations. Fluence-map editing provides manual control of dose delivery and provides the best treatment plan possible. Several IMRT treatments were planned using the Varian Eclipse planning system. We compare the effects on dose distributions between fluence-map editing and re-optimization, discuss techniques for fluence-map editing, and analyze differences between fluence editing on one beam vs. multiple beams. When editing a beam's fluence map, it is essential to choose a beam that least affects dose to the tumor and critical structures. Editing fluence maps gives an advantage in treatment planning and provides controlled delivery of IMRT dose

  9. Metastatic meningioma presenting as cancer of unknown primary

    Directory of Open Access Journals (Sweden)

    Vinay Gupta

    2013-12-01

    Full Text Available We describe a case of anaplastic meningioma presenting in an extracranial osseous location, initially diagnosed as cancer of unknown primary. Although anaplastic meningioma comprise 3% of all meningiomas, this subtype is more likely to be associated with metastases. The increased degree of dedifferentiation in anaplastic meningioma makes diagnosis difficult, especially if characteristic imaging findings of meningioma are not identified. Adequate tissue for diagnostic purposes and appropriate imaging studies may help in establishing a definitive diagnosis.

  10. IMRT plan verification in radiotherapy

    International Nuclear Information System (INIS)

    Vlk, P.

    2006-01-01

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

  11. Receptores de progesterona en meningioma.

    Directory of Open Access Journals (Sweden)

    Herminio Ojeda Di Ninno

    1995-04-01

    Full Text Available Objetivo: Determinar la presencia de los receptores de progesterona en meningiomas y su frecuencia mediante la inmunohistoquímica. Material y Métodos: Se analizaron 24 muestras provenientes de pacientes intervenidos quirúrgicamente en el Instituto Nacional de Enfermedades Neoplásicas entre los años 1990 y 1992 con diagnóstico anatomopatológico de meningioma. La determinación de los receptores se hizo mediante una técnica de inmunohistoquímica rápida que permite el estudio de tejidos fijados previamente en parafina. Resultados: De los 24 casos estudiados, nueve resultaron ser positivos en la determinación de receptores de progesterona (37%. Se pudo observar un marcado predominio dentro del grupo femenino quienes constituyeron 8/9 casos positivos. Conclusiones: El empleo de esta reciente técnica de inmunohistoquímica aplicada a tejido de fijado en parafina, nos ha permitido confirmar la presencia de receptores de progesterona en meningiomas con una frecuencia elevada que creemos amerita un estudio más amplio de manera sistemática que incluya la intervención terapéutica mediante el uso de antiprogestágenos, como el Mifepristone o RU 486. De este estudio podrían beneficiarse no sólo pacientes operados recientemente sino aquellos que, intervenidos en el pasado sean detectados como portadores de receptores de progesterona mediante la aplicación de esta novedosa técnica (Rev Med Hered 1995; 6: 121-130.

  12. Clinical and dosimetric evaluation of RapidArc versus standard sliding window IMRT in the treatment of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Smet, Stephanie; Lambrecht, Maarten; Vanstraelen, Bianca; Nuyts, Sandra [University Hospitals Leuven, Department of Radiation Oncology, Leuven (Belgium)

    2014-08-29

    Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome. CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0. PTV coverage with the 95 % isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62 % in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA. In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis. (orig.) [German] Mehrere Studien haben die dosimetrische Ueberlegenheit der RapidArc (RA) gegenueber der intensitaetsmodulierten Standard-Radiotherapie (IMRT) bereits gezeigt. In unserer Studie verglichen wir retrospektiv die RapidArc und die dynamische (''standard sliding window'') IMRT (swIMRT) bei lokal fortgeschrittenen Kopf-Hals-Karzinomen sowohl hinsichtlich dosimetrischer Daten als auchEffektivitaet und Toxizitaet. Die CT-Datenanalysen von 78 Patienten, die mit swIMRT behandelt wurden, und von 79 Patienten, welche RA erhalten hatten, wurden in die Studie aufgenommen. Um die darauf resultierenden applizierten Dosen vergleichen zu koennen, wurden die Dosis-Volumen-Parameter fuer

  13. Surgical experience with skull base approaches for foramen magnum meningioma.

    Science.gov (United States)

    Marin Sanabria, Elio Arnaldo; Ehara, Kazumasa; Tamaki, Norihiko

    2002-11-01

    The surgical treatment of patients with foramen magnum meningioma remains challenging. This study evaluated the outcome of this tumor according to the evolution of surgical approaches during the last 29 years. A retrospective analysis of medical records, operative notes, and neuroimages of 492 meningioma cases from 1972 to 2001 identified seven cases of foramen magnum meningioma (1.4%). All patients showed various neurological symptoms corresponding with foramen magnum syndrome. The tumor locations were anterior in five cases and posterior in two. Surgical removal was performed through a transoral approach in one patient, the suboccipital approach in three, and the transcondylar approach in two. Total removal was achieved in all patients, except for one who refused any surgical treatment. The major complications were tetraparesis and lower cranial nerve paresis for tumors in anterior locations, and minor complications for posterior locations. One patient died of atelectasis and pneumonia after a long hospitalization. The transcondylar approach is recommended for anterior locations, and the standard suboccipital approach for posterior locations.

  14. Prospective, longitudinal, multi-modal functional imaging for radical chemo-IMRT treatment of locally advanced head and neck cancer: the INSIGHT study

    International Nuclear Information System (INIS)

    Welsh, Liam; Panek, Rafal; McQuaid, Dualta; Dunlop, Alex; Schmidt, Maria; Riddell, Angela; Koh, Dow-Mu; Doran, Simon; Murray, Iain; Du, Yong; Chua, Sue; Hansen, Vibeke; Wong, Kee H.; Dean, Jamie; Gulliford, Sarah; Bhide, Shreerang; Leach, Martin O.; Nutting, Christopher; Harrington, Kevin; Newbold, Kate

    2015-01-01

    Radical chemo-radiotherapy (CRT) is an effective organ-sparing treatment option for patients with locally advanced head and neck cancer (LAHNC). Despite advances in treatment for LAHNC, a significant minority of these patients continue to fail to achieve complete response with standard CRT. By constructing a multi-modality functional imaging (FI) predictive biomarker for CRT outcome for patients with LAHNC we hope to be able to reliably identify those patients at high risk of failing standard CRT. Such a biomarker would in future enable CRT to be tailored to the specific biological characteristics of each patients’ tumour, potentially leading to improved treatment outcomes. The INSIGHT study is a single-centre, prospective, longitudinal multi-modality imaging study using functional MRI and FDG-PET/CT for patients with LAHNC squamous cell carcinomas receiving radical CRT. Two cohorts of patients are being recruited: one treated with, and another treated without, induction chemotherapy. All patients receive radical intensity modulated radiotherapy with concurrent chemotherapy. Patients undergo functional imaging before, during and 3 months after completion of radiotherapy, as well as at the time of relapse, should that occur within the first two years after treatment. Serum samples are collected from patients at the same time points as the FI scans for analysis of a panel of serum markers of tumour hypoxia. The primary aim of the INSIGHT study is to acquire a prospective multi-parametric longitudinal data set comprising functional MRI, FDG PET/CT, and serum biomarker data from patients with LAHNC undergoing primary radical CRT. This data set will be used to construct a predictive imaging biomarker for outcome after CRT for LAHNC. This predictive imaging biomarker will be used in future studies of functional imaging based treatment stratification for patients with LAHNC. Additional objectives are: defining the reproducibility of FI parameters; determining robust

  15. Alternated Prone and Supine Whole-Breast Irradiation Using IMRT: Setup Precision, Respiratory Movement and Treatment Time

    International Nuclear Information System (INIS)

    Veldeman, Liv; De Gersem, Werner; Speleers, Bruno; Truyens, Bart; Van Greveling, Annick; Van den Broecke, Rudy; De Neve, Wilfried

    2012-01-01

    Purpose: The objective of this study was to compare setup precision, respiration-related breast movement and treatment time between prone and supine positions for whole-breast irradiation. Methods and Materials: Ten patients with early-stage breast carcinoma after breast-conserving surgery were treated with prone and supine whole breast-irradiation in a daily alternating schedule. Setup precision was monitored using cone-beam computed tomography (CBCT) imaging. Respiration-related breast movement in the vertical direction was assessed by magnetic sensors. The time needed for patient setup and for the CBCT procedure, the beam time, and the length of the whole treatment slot were also recorded. Results: Random and systematic errors were not significantly different between positions in individual patients for each of the three axes (left-right, longitudinal, and vertical). Respiration-related movement was smaller in prone position, but about 80% of observations showed amplitudes <1 mm in both positions. Treatment slots were longer in prone position (21.2 ± 2.5 min) than in supine position (19.4 ± 0.8 min; p = 0.044). Conclusion: Comparison of setup precision between prone and supine position in the same patient showed no significant differences in random and systematic errors. Respiratory movement was smaller in prone position. The longer treatment slots in prone position can probably be attributed to the higher repositioning need.

  16. MRI findings of intracranial cystic meningiomas

    International Nuclear Information System (INIS)

    Zhang, D.; Hu, L.-B.; Zhen, J.W.; Zou, L.-G.; Feng, X.-Y.; Wang, W.-X.; Wen, L.

    2009-01-01

    Aim: To report the magnetic resonance imaging (MRI) features of intracranial cystic meningiomas and compare these features in intra- and peritumoural cyst groups. Materials and methods: Fourteen cases of peritumoural cystic meningiomas were compared with 18 cases of intratumoural cystic meningiomas. All patients were examined using non-enhanced and contrast-enhanced MRI. Tumour location, tumour size, signal intensity, enhancement characteristics, and cystic changes were assessed. The MRI features were compared between the intra- and peritumoural cyst groups. Results: Most cystic meningiomas comprised two or more cysts. The solid parts of the tumours showed moderate or marked enhancement after the injection of contrast material. An enhanced cyst wall was found in six out of 14 cases in the peritumoural cyst group, but not in the intratumoural cyst group. Peritumoural cystic meningiomas were predominately located in the cerebral falx, whereas the intratumoural cystic meningiomas were predominantly found in frontal convexity (X 2 = 7.434, p = 0.024). The cysts were larger in the peritumoural cyst group than in the intratumoural cyst group (t = 5.274, p = 0.0258). Peritumoural oedema was more commonly found in the intratumoural cyst group (X 2 = 6.863, p = 0.008). Cystic meningiomas with solid parts located inside the cyst are reported for the first time. Conclusion: Cystic meningiomas, although uncommon, should be differentiated from other cystic intracranial lesions. Peri- and intratumoural cystic meningiomas have distinct MRI features. The present study provides the first report of two lesions with solid parts located inside the cyst, as well as one lesion with a calcified solid nodule and haemorrhage within the cyst.

  17. Inverse IMRT workflow process at Austin health

    International Nuclear Information System (INIS)

    Rykers, K.; Fernando, W.; Grace, M.; Liu, G.; Rolfo, A.; Viotto, A.; Mantle, C.; Lawlor, M.; Au-Yeung, D.; Quong, G.; Feigen, M.; Lim-Joon, D.; Wada, M.

    2004-01-01

    Full text: The work presented here will review the strategies adopted at Austin Health to bring IMRT into clinical use. IMRT is delivered using step and shoot mode on an Elekta Precise machine with 40 pairs of 1cm wide MLC leaves. Planning is done using CMS Focus/XiO. A collaborative approach for RO's, Physicists and RTs from concept to implementation was adopted. An overview will be given of the workflow for the clinic, the equipment used, tolerance levels and the lessons learned. 1. Strategic Planning for IMRT 2. Training a. MSKCC (New York) b.ESTRO (Amsterdam) c.Elekta (US and UK) 3. Linac testing and data acquisition a. Equipment and software review and selection b. Linac reliability/geometric and mechanical checks c. Draft Patient QA procedure d. EPI Image matching checks and procedures 4. Planning system checks a. export of dose matrix (options) b. dose calculation choices 5. IMRT Research Initiatives a. IMRT Planning Studies, Stabilisation, On-line Imaging 6. Equipment Procurement and testing a. Physics and Linac Equipment, Hardware, Software/Licences, Stabilisation 7. Establishing a DICOM Environment a. Prescription sending, Image transfer for EPI checks b. QA Files 8. Physics QA (Pre-Treatment) a.Clinical plan review; DVH checks b. geometry; dosimetry checks; DICOM checks c. 2D Distance to agreement; mm difference reports; Gamma function index 9. Documentation a.Protocol Development i. ICRU 50/62 reporting and prescribing b. QA for Physics c. QA for RT's d. Generation of a report for RO/patient history. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  18. A feasibility study of using conventional jaws to deliver complex IMRT plans for head and neck cancer

    International Nuclear Information System (INIS)

    Mu, G; Xia, P

    2009-01-01

    Previous studies have demonstrated that simple intensity-modulated radiotherapy (IMRT) plans can be produced with a series of rectangular segments formed by conventional jaws. This study investigates whether complex IMRT plans for head and neck cancer can be delivered with the conventional jaws efficiently. Six nasopharyngeal cancer patients, previously treated with multi-leaf collimator (MLC)-IMRT plans, were re-planned using conventional jaw delivery options. All IMRT plans were subject to the plan acceptance criteria of the RTOG-0225 protocol. For a selected patient, the maximum number of segments varied from five to nine per beam, and was tested for both jaws-only IMRT (JO-IMRT) plans and MLC-IMRT plans. Subsequently, JO-IMRT plans and MLC-IMRT on the same treatment planning system were attempted for all patients with identical beams. The dose distribution, dose volume histograms (DVH), the conformal index (COIN), the uniformity index and delivery efficiency were compared between the MLC-IMRT and JO-IMRT plans. All JO-IMRT plans met the RTOG-0225 criteria for tumor coverage and sensitive structures sparing. The corresponding MLC-IMRT and JO-IMRT plans show comparable conformality and uniformity, with average COINs of the planning gross tumor volume(pGTV) 37.7% ± 18.7% versus 37.9% ± 18.1%, and the average uniformity index 82.8% ± 2.5% versus 83.6% ± 3.1%, respectively. The average monitor unit for JO-IMRT plans was about twice that of MLC-IMRT plans. In conclusion, conventional jaws can be used solely to deliver complex IMRT plans for patients with nasopharyngeal cancer yet still within a practical delivery time.

  19. Alternated prone and supine whole-breast irradiation using IMRT: setup precision, respiratory movement and treatment time.

    Science.gov (United States)

    Veldeman, Liv; De Gersem, Werner; Speleers, Bruno; Truyens, Bart; Van Greveling, Annick; Van den Broecke, Rudy; De Neve, Wilfried

    2012-04-01

    The objective of this study was to compare setup precision, respiration-related breast movement and treatment time between prone and supine positions for whole-breast irradiation. Ten patients with early-stage breast carcinoma after breast-conserving surgery were treated with prone and supine whole breast-irradiation in a daily alternating schedule. Setup precision was monitored using cone-beam computed tomography (CBCT) imaging. Respiration-related breast movement in the vertical direction was assessed by magnetic sensors. The time needed for patient setup and for the CBCT procedure, the beam time, and the length of the whole treatment slot were also recorded. Random and systematic errors were not significantly different between positions in individual patients for each of the three axes (left-right, longitudinal, and vertical). Respiration-related movement was smaller in prone position, but about 80% of observations showed amplitudes movement was smaller in prone position. The longer treatment slots in prone position can probably be attributed to the higher repositioning need. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. A rare case of multiple meningiomas with different histology

    Directory of Open Access Journals (Sweden)

    Toma I. Papacocea

    2017-11-01

    Full Text Available Meningiomas are generally benign tumors but sometimes they manifest tendency to progress towards malignancy. It is not yet clear if anaplastic meningiomas have an innate malignancy characteristic, or an initially beginning histological appearance that degenerates malignantly in time. According to literature data, the risk of a benign meningioma to progress towards malignant phenotype is about 0.16-2%, such malignant transformation occurring after a variable period of time (2-16 years. A still unanswered question is how many of the malignant meningiomas present this appearance as an innate feature and how many of them originate from benign meningiomas. Multiple meningiomas are defined as the presence of two or more distinct meningiomas. They occur in 6-10% of all patients that present meningiomas. Multiple meningiomas with a distinct histological appearance are rarely discovered. They support the theory of meningiomas that develop independently in the same patient. Different histology of multiple meningiomas is found in less than a third of the patients who suffer from this pathology. We are presenting the case of a patient with multiple meningiomas with distinct histology, one being benign and the other malignant. In connection with this case we are raising a question of therapeutic management in patients diagnosed with malignant meningiomas, namely if other possible small/ benign meningiomas should be also entirely resected.

  1. IMRT in hypopharyngeal tumors

    Energy Technology Data Exchange (ETDEWEB)

    Studer, G.; Luetolf, U.M.; Davis, J.B.; Glanzmann, C. [Dept. of Radiation Oncology, Univ. Hospital, Zurich (Switzerland)

    2006-06-15

    Background and purpose: intensity-modulated radiation therapy (IMRT) data on hypopharyngeal cancer (HC) are scant. In this study, the authors report on early results in an own HC patient cohort treated with IMRT. A more favorable outcome as compared to historical data on conventional radiation techniques was expected. Patients and methods: 29 consecutive HC patients were treated with simultaneous integrated boost (SIB) IMRT between 01/2002 and 07/2005 (mean follow-up 16 months, range 4-44 months). Doses of 60-71 Gy with 2.0-2.2 Gy/fraction were applied. 26/29 patients were definitively irradiated, 86% received simultaneous cisplatin-based chemotherapy. 60% presented with locally advanced disease (T3/4 Nx, Tx N2c/3). Mean primary tumor volume measured 36.2 cm{sup 3} (4-170 cm{sup 3}), mean nodal volume 16.6 cm{sup 3} (0-97 cm{sup 3}). Results: 2-year actuarial local, nodal, distant control, and overall disease-free survival were 90%, 93%, 93%, and 90%, respectively. In 2/4 patients with persistent disease (nodal in one, primary in three), salvage surgery was performed. The mean dose to the spinal cord (extension of > 5-15 mm) was 26 Gy (12-38 Gy); the mean maximum (point) dose was 44.4 Gy (26-58.9 Gy). One grade (G) 3 dysphagia and two G4 reactions (laryngeal fibrosis, dysphagia), both following the schedule with 2.2 Gy per fraction, have been observed so far. Larynx preservation was achieved in 25/26 of the definitively irradiated patients (one underwent a salvage laryngectomy); 23 had no or minimal dysphagia (G0-1). Conclusion: excellent early disease control and high patient satisfaction with swallowing function in HC following SIB IMRT were observed; these results need to be confirmed based on a longer follow-up period. In order to avoid G4 reactions, SIB doses of < 2.2 Gy/fraction are recommended for large tumors involving laryngeal structures. (orig.)

  2. Exclusive image guided IMRT vs. radical prostatectomy followed by postoperative IMRT for localized prostate cancer: a matched-pair analysis based on risk-groups

    International Nuclear Information System (INIS)

    Azelie, Caroline; Créhange, Gilles; Gauthier, Mélanie; Mirjolet, Céline; Cormier, Luc; Martin, Etienne; Peignaux-Casasnovas, Karine; Truc, Gilles; Chamois, Jérôme; Maingon, Philippe

    2012-01-01

    To investigate whether patients treated for a localized prostate cancer (PCa) require a radical prostatectomy followed by postoperative radiotherapy or exclusive radiotherapy, in the modern era of image guided IMRT. 178 patients with PCa were referred for daily exclusive image guided IMRT (IG-IMRT) using an on-line 3D ultra-sound based system and 69 patients were referred for postoperative IMRT without image guidance after radical prostatectomy (RP + IMRT). Patients were matched in a 1:1 ratio according to their baseline risk group before any treatment. Late toxicity was scored using the CTV v3.0 scale. Biochemical failure was defined as a postoperative PSA ≤ 0.1 ng/mL followed by 1 consecutive rising PSA for the postoperative group of patients and by the Phoenix definition (nadir + 2 ng/mL) for the group of patients treated with exclusive radiotherapy. A total of 98 patients were matched (49:49). From the start of any treatment, the median follow-up was 56.6 months (CI 95% = [49.6-61.2], range [18.2-115.1]). No patient had late gastrointestinal grade ≥ 2 toxicity in the IG-IMRT group vs. 4% in the RP + IMRT group. Forty two percent of the patients in both groups had late grade ≥ 2 genitourinary toxicity. The 5-year FFF rates in the IG-IMRT group and in the RP + IMRT groups were 93.1% [80.0-97.8] and 76.5% [58.3-87.5], respectively (p = 0.031). Patients with a localized PCa treated with IG-IMRT had better oncological outcome than patients treated with RP + IMRT. Further improvements in postoperative IMRT using image guidance and dose escalation are urgently needed

  3. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    International Nuclear Information System (INIS)

    Stiebel-Kalish, Hadas; Reich, Ehud; Gal, Lior; Rappaport, Zvi Harry; Nissim, Ouzi; Pfeffer, Raphael; Spiegelmann, Roberto

    2012-01-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  4. SU-E-T-133: Assessing IMRT Treatment Delivery Accuracy and Consistency On a Varian TrueBeam Using the SunNuclear PerFraction EPID Dosimetry Software

    Energy Technology Data Exchange (ETDEWEB)

    Dieterich, S [UC Davis Medical Center, Sacramento, CA (United States); Trestrail, E; Holt, R [Pacific Crest Medical Physics, Chico, CA (United States); Saini, S [Sun Nuclear Corporation, Melbourne, FL (Australia); Pfeiffer, I [VMTH, UC Davis, Davis, CA (United States); Kent, M; Hansen, K [Surgical and Radiological Sciences, UC Davis, Davis, CA (United States)

    2015-06-15

    Purpose: To assess if the TrueBeam HD120 collimator is delivering small IMRT fields accurately and consistently throughout the course of treatment using the SunNuclear PerFraction software. Methods: 7-field IMRT plans for 8 canine patients who passed IMRT QA using SunNuclear Mapcheck DQA were selected for this study. The animals were setup using CBCT image guidance. The EPID fluence maps were captured for each treatment field and each treatment fraction, with the first fraction EPID data serving as the baseline for comparison. The Sun Nuclear PerFraction Software was used to compare the EPID data for subsequent fractions using a Gamma (3%/3mm) pass rate of 90%. To simulate requirements for SRS, the data was reanalyzed using a Gamma (3%/1mm) pass rate of 90%. Low-dose, low- and high gradient thresholds were used to focus the analysis on clinically relevant parts of the dose distribution. Results: Not all fractions could be analyzed, because during some of the treatment courses the DICOM tags in the EPID images intermittently change from CU to US (unspecified), which would indicate a temporary loss of EPID calibration. This technical issue is still being investigated. For the remaining fractions, the vast majority (7/8 of patients, 95% of fractions, and 96.6% of fields) are passing the less stringent Gamma criteria. The more stringent Gamma criteria caused a drop in pass rate (90 % of fractions, 84% of fields). For the patient with the lowest pass rate, wet towel bolus was used. Another patient with low pass rates experienced masseter muscle wasting. Conclusion: EPID dosimetry using the PerFraction software demonstrated that the majority of fields passed a Gamma (3%/3mm) for IMRT treatments delivered with a TrueBeam HD120 MLC. Pass rates dropped for a DTA of 1mm to model SRS tolerances. PerFraction pass rates can flag missing bolus or internal shields. Sanjeev Saini is an employee of Sun Nuclear Corporation. For this study, a pre-release version of PerFRACTION 1

  5. Prostate carcinoma mimicking a sphenoid wing meningioma

    Directory of Open Access Journals (Sweden)

    Lucas H. Bradley

    2015-01-01

    Conclusion: We conclude that dural-based metastatic lesions may mimic meningiomas, warranting thorough pre-operative work-up to exclude the possibility of metastasis. In certain cases, identification of widespread disease might preclude surgery and favor palliation, instead.

  6. Atypical imaging appearances of intracranial meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, S. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Adams, W.M. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Parrish, R.W. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Mukonoweshuro, W. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom)]. E-mail: William.mukonoweshuro@phnt.swest.nhs.uk

    2007-01-15

    Meningiomas are the commonest primary, non-glial intracranial tumours. The diagnosis is often correctly predicted from characteristic imaging appearances. This paper presents some examples of atypical imaging appearances that may cause diagnostic confusion.

  7. SU-E-T-428: Dosimetric Impact of Multileaf Collimator Leaf Width On Single and multiple Isocenter Stereotactic IMRT Treatment Plans for multiple Brain Tumors

    International Nuclear Information System (INIS)

    Giem, J; Algan, O; Ahmad, S; Ali, I; Young, J; Hossain, S

    2014-01-01

    Purpose: To assess the impacts that multileaf collimator (MLC) leaf width has on the dose conformity and normal brain tissue doses of single and multiple isocenter stereotactic IMRT (SRT) plans for multiple intracranial tumors. Methods: Fourteen patients with 2–3 targets were studied retrospectively. Patients treated with multiple isocenter treatment plans using 9 to 12 non-coplanar beams per lesion underwent repeat planning using single isocenter and 10 to 12 non-coplanar beams with 2.5mm, 3mm and 5mm MLC leaf widths. Brainlab iPlan treatment planning system for delivery with the 2.5mm MLC served as reference. Identical contour sets and dose-volume constraints were applied. The prescribed dose to each target was 25 Gy to be delivered over 5 fractions with a minimum of 99% dose to cover ≥ 95% of the target volume. Results: The lesions and normal brains ranged in size from 0.11 to 51.67cc (median, 2.75cc) and 1090 to 1641cc (median, 1401cc), respectively. The Paddick conformity index for single and multiple isocenter (2.5mm vs. 3mm and 5mm MLCs) was (0.79±0.08 vs. 0.79±0.07 and 0.77±0.08) and (0.79±0.09 vs. 0.77±0.09 and 0.76±0.08), respectively. The average normal brain volumes receiving 15 Gy for single and multiple isocenter (2.5mm vs. 3mm and 5mm MLCs) were (3.65% vs. 3.95% and 4.09%) and (2.89% vs. 2.91% and 2.92%), respectively. Conclusion: The average dose conformity observed for the different leaf width for single and multiple isocenter plans were similar, throughout. However, the average normal brain volumes receiving 2.5 to 15 Gy were consistently lower for the 2.5mm MLC leaf width, especially for single isocenter plans. The clinical consequences of these integral normal brain tissue doses are still unknown, but employing the use of the 2.5mm MLC option is desirable at sparing normal brain tissue for both single and multiple isocenter cases

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

    International Nuclear Information System (INIS)

    Ahmed, Raef S.; Ove, Roger; Duan, Jun; Popple, Richard; Cobb, Glenn

    2006-01-01

    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

  9. Emphasizing Conformal Avoidance Versus Target Definition for IMRT Planning in Head-and-Neck Cancer

    International Nuclear Information System (INIS)

    Harari, Paul M.; Song Shiyu; Tome, Wolfgang A.

    2010-01-01

    Purpose: To describe a method for streamlining the process of elective nodal volume definition for head-and-neck (H and N) intensity-modulated radiotherapy (IMRT) planning. Methods and Materials: A total of 20 patients who had undergone curative-intent RT for H and N cancer underwent comprehensive treatment planning using three distinct, plan design techniques: conventional three-field design, target-defined IMRT (TD-IMRT), and conformal avoidance IMRT (CA-IMRT). For each patient, the conventional three-field design was created first, thereby providing the 'outermost boundaries' for subsequent IMRT design. In brief, TD-IMRT involved physician contouring of the gross tumor volume, high- and low-risk clinical target volume, and normal tissue avoidance structures on consecutive 1.25-mm computed tomography images. CA-IMRT involved physician contouring of the gross tumor volume and normal tissue avoidance structures only. The overall physician time for each approach was monitored, and the resultant plans were rigorously compared. Results: The average physician working time for the design of the respective H and N treatment contours was 0.3 hour for the conventional three-field design plan, 2.7 hours for TD-IMRT, and 0.9 hour for CA-IMRT. Dosimetric analysis confirmed that the largest volume of tissue treated to an intermediate (50 Gy) and high (70 Gy) dose occurred with the conventional three-field design followed by CA-IMRT and then TD-IMRT. However, for the two IMRT approaches, comparable results were found in terms of salivary gland and spinal cord protection. Conclusion: CA-IMRT for H and N treatment offers an alternative to TD-IMRT. The overall time for physician contouring was substantially reduced (approximately threefold), yielding a more standardized elective nodal volume. Because of the complexity of H and N IMRT target design, CA-IMRT might ultimately prove a safer and more reliable method to export to general radiation oncology practitioners, particularly

  10. Effects of sex on the incidence and prognosis of spinal meningiomas: a Surveillance, Epidemiology, and End Results study.

    Science.gov (United States)

    Westwick, Harrison J; Shamji, Mohammed F

    2015-09-01

    Most spinal meningiomas are intradural lesions in the thoracic spine that present with both local pain and myelopathy. By using the large prospective Surveillance, Epidemiology, and End Results (SEER) database, the authors studied the incidence of spinal meningiomas and examined demographic and treatment factors predictive of death. Using SEER*Stat software, the authors queried the SEER database for cases of spinal meningioma between 2000 and 2010. From the results, tumor incidence and demographic statistics were computed; incidence was analyzed as a function of tumor location, pathology, age, sex, and malignancy code. Survival was analyzed by using a Cox proportional hazards ratio in SPSS for age, sex, marital status, primary site, size quartile, treatment modality, and malignancy code. In this analysis, significance was set at a p value of 0.05. The 1709 spinal meningiomas reported in the SEER database represented 30.7% of all primary intradural spinal tumors and 7.9% of all meningiomas. These meningiomas occurred at an age-adjusted incidence of 0.193 (95% CI 0.183-0.202) per 100,000 population and were closely related to sex (337 [19.7%] male patients and 1372 [80.3%] female patients). The Cox hazard function for mortality in males was higher (2.4 [95% CI1.7-3.5]) and statistically significant, despite the lower lesion incidence in males. All-cause survival was lowest in patients older than 80 years. Primary site and treatment modality were not significant predictors of mortality. Spinal meningiomas represent a significant fraction of all primary intradural spinal tumors and of all meningiomas. The results of this study establish the association of lesion incidence and survival with sex, with a less frequent incidence in but greater mortality among males.

  11. An absorbed dose calorimeter for IMRT dosimetry

    International Nuclear Information System (INIS)

    Duane, S.; Aldehaybes, M.; Bailey, M.; Lee, N.D.; Thomas, C.G.; Palmans, H.

    2012-01-01

    A new calorimeter for dosimetry in small and complex fields has been built. The device is intended for the direct determination of absorbed dose to water in moderately small fields and in composite fields such as IMRT treatments, and as a transfer instrument calibrated against existing absorbed dose standards in conventional reference conditions. The geometry, materials and mode of operation have been chosen to minimize detector perturbations when used in a water phantom, to give a reasonably isotropic response and to minimize the effects of heat transfer when the calorimeter is used in non-reference conditions in a water phantom. The size of the core is meant to meet the needs of measurement in IMRT treatments and is comparable to the size of the air cavity in a type NE2611 ionization chamber. The calorimeter may also be used for small field dosimetry. Initial measurements in reference conditions and in an IMRT head and neck plan, collapsed to gantry angle zero, have been made to estimate the thermal characteristics of the device, and to assess its performance in use. The standard deviation (estimated repeatability) of the reference absorbed dose measurements was 0.02 Gy (0.6%). (authors)

  12. Tumor Volume Decrease via Feeder Occlusion for Treating a Large, Firm Trigone Meningioma.

    Science.gov (United States)

    Nakashima, Takuma; Hatano, Norikazu; Kanamori, Fumiaki; Muraoka, Shinsuke; Kawabata, Teppei; Takasu, Syuntaro; Watanabe, Tadashi; Kojima, Takao; Nagatani, Tetsuya; Seki, Yukio

    2018-01-01

    Trigone meningiomas are considered a surgical challenge, as they tend to be considerably large and hypervascularized at the time of presentation. We experienced a case of a large and very hard trigone meningioma that was effectively treated using initial microsurgical feeder occlusion followed by surgery in stages. A 19-year-old woman who presented with loss of consciousness was referred to our hospital for surgical treatment of a brain tumor. Radiological findings were compatible with a left ventricular trigone meningioma extending laterally in proximity to the Sylvian fissure. At initial surgery using the transsylvian approach, main feeders originating from the anterior and lateral posterior choroidal arteries were occluded at the inferior horn; however, only a small section of the tumor could initially be removed because of its firmness. Over time, feeder occlusion resulted in tumor necrosis and a 20% decrease in its diameter; the mass effect was alleviated within 1 year. The residual meningioma was then totally excised in staged surgical procedures after resection became more feasible owing to ischemia-induced partial softening of the tumor. When a trigone meningioma is large and very hard, initial microsurgical feeder occlusion in the inferior horn can be a safe and effective option, and can lead to necrosis, volume decrease, and partial softening of the residual tumor to allow for its staged surgical excision.

  13. Brain meningioma with initial manifestation similar to cervical radiculopathy: a case report

    Directory of Open Access Journals (Sweden)

    Huang YH

    2014-06-01

    Full Text Available Yu-Hsuan Huang,1,* Chang-Zern Hong,2,* Wei-Ting Wu,1 Kun-Ta Li,3 Li-Wei Chou1,4¹Department of Physical Medicine and Rehabilitation, China Medical University Hospital, 2Department of Physical Therapy, Hungkuang University, 3Department of Emergency Medicine, China Medical University Hospital, 4School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan*These authors contributed equally to this workAbstract: Meningiomas are the most common benign brain tumors, and are characterized by slow growth and a long asymptomatic period. Once the tumor becomes symptomatic, the various presentations may be related to the location and compression of adjacent structures. Meningioma is primarily treated through surgical intervention, and thus earlier diagnosis is likely to result in better prognosis. The symptoms of the meningioma may mimic other diseases, making precise diagnosis difficult, which will then delay treatment. We report a case of brain meningioma that showed initial signs and symptoms similar to cervical radiculopathy. The symptoms extended gradually, and the ultimate diagnosis of meningioma was confirmed based on brain-image studies. After brain-tumor excision, postoperation radiotherapy, and aggressive rehabilitation, the patient was able to perform better in daily activities.Keywords: hemiplegia, menigioma, paresthesia, radiculopathy, rehabilitation

  14. Primary brain tumours, meningiomas and brain metastases in pregnancy

    DEFF Research Database (Denmark)

    Verheecke, Magali; Halaska, Michael J; Lok, Christianne A

    2014-01-01

    to obtain better insight into outcome and possibilities of treatment in pregnancy. METHODS: We collected all intracranial tumours (primary brain tumour, cerebral metastasis, or meningioma) diagnosed during pregnancy, registered prospectively and retrospectively by international collaboration since 1973......, respectively. Eight patients (30%) underwent brain surgery, seven patients (26%) had radiotherapy and in three patients (11%) chemotherapy was administered during gestation. Two patients died during pregnancy and four pregnancies were terminated. In 16 (59%) patients elective caesarean section was performed...... were reassuring. CONCLUSION: Adherence to standard protocol for the treatment of brain tumours during pregnancy appears to allow a term delivery and a higher probability of a vaginal delivery....

  15. Surgical Management of Olfactory Groove Meningiomas | El-Naggar ...

    African Journals Online (AJOL)

    Objective: To study the bifrontal approach to olfactory groove meningiomas ... in all patients was Grade I meningiomas (World Health Organization grading). ... Bifrontal approach offers excellent exposure, and when combined with modern ...

  16. Predictors of severe complications in intracranial meningioma surgery

    DEFF Research Database (Denmark)

    Bartek, Jiri; Sjåvik, Kristin; Förander, Petter

    2015-01-01

    OBJECTIVE: To investigate predictors of complications after intracranial meningioma resection using a standardized reporting system for adverse events. METHODS: A retrospective review was conducted in a Scandinavian population-based cohort of 979 adult operations for intracranial meningioma perfo...

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  19. Molecular signatures define two main classes of meningiomas

    Directory of Open Access Journals (Sweden)

    Costello Joseph F

    2007-10-01

    Full Text Available Abstract Background Meningiomas are common brain tumors that are classified into three World Health Organization grades (benign, atypical and malignant and are molecularly ill-defined tumors. The purpose of this study was identify molecular signatures unique to the different grades of meningiomas and to unravel underlying molecular mechanisms driving meningioma tumorigenesis. Results We have used a combination of gene expression microarrays and array comparative genomic hybridization (aCGH to show that meningiomas of all three grades fall into two main molecular groups designated 'low-proliferative' and 'high-proliferative' meningiomas. While all benign meningiomas fall into the low-proliferative group and all malignant meningiomas fall into the high-proliferative group, atypical meningiomas distribute into either one of these groups. High-proliferative atypical meningiomas had an elevated median MIB-1 labeling index and a greater frequency of copy number aberrations (CNAs compared to low-proliferative atypical meningiomas. Additionally, losses on chromosome 6q, 9p, 13 and 14 were found exclusively in the high-proliferative meningiomas. We have identified genes that distinguish benign low-proliferative meningiomas from malignant high-proliferative meningiomas and have found that gain of cell-proliferation markers and loss of components of the transforming growth factor-beta signaling pathway were the major molecular mechanisms that distinguish these two groups. Conclusion Collectively, our data suggests that atypical meningiomas are not a molecularly distinct group but are similar to either benign or malignant meningiomas. It is anticipated that identified molecular and CNA markers will potentially be more accurate prognostic markers of meningiomas.

  20. Skull base chordoid meningioma: Imaging features and pathology

    International Nuclear Information System (INIS)

    Soo, Mark Y.S.; Gomes, Lavier; Ng, Thomas; Cruz, Malville Da; Dexter, Mark

    2004-01-01

    The clinical, imaging and pathological features of a skull base chordoid meningioma (CM) are described. The huge tumour resulted in obstructive hydrocephalus and partial erosion of the clivus such that a chordoma was suspected. The lesion's MRI findings were similar to those of a meningioma. Light microscopic, immunohistochemistry and ultrastructural features were diagnostic of CM. Chordoid meningioma is a rare subtype of meningioma and has a great tendency to recur should surgical resection be incomplete Copyright (2004) Blackwell Publishing Asia Pty Ltd

  1. Meningiomas anteriores e antero-laterais do forame magno Anterior and lateral foramen magnum meningiomas

    Directory of Open Access Journals (Sweden)

    Osvaldo Inácio de Tella Jr

    2006-06-01

    Full Text Available Relatamos nossa experiência com 11 pacientes portadores de meningiomas do forame magno, oito cranioespinhais e três espinocraniais. A média de idade foi 50,8 anos, o sintoma mais comum foi cefaléia occipital com duração média de 18,6 meses. Os principais achados neurológicos foram tetraparesia e comprometimento dos nervos cranianos baixos. O tratamento foi cirúrgico, sempre com exposição da artéria vertebral em sua entrada na dura-máter da fossa posterior e ressecção de parte do côndilo occipital apenas em três casos. Ressecção total foi possível em sete pacientes e parcial nos demais, devido às aderências a vasos e nervos. O prognóstico esteve relacionado com as condições neurológicas pré-operatórias.We report our experience with 11 cases of foramen magnum meningiomas, eight originating inside the posterior fossa and three in the caudal region. The mean age of the patients was 50.8 years and the main complaint was cervical headache for at least 18.6 months and at the neurological examination, tetraparesis and deficit of the lower cranial nerves were very often observed. All patients were submitted to surgical treatment, always with exposition of the vertebral artery at the entry zone in the duramater of the posterior fossa, with partial removal of the occipital condyle in only three cases. Total resection was obtained in seven patients and partial removal in the other four due to adherences to vessels and nerves. The prognostic was related to the neurological condition before surgery.

  2. IMRT for adjuvant radiation in gastric cancer: A preferred plan?

    International Nuclear Information System (INIS)

    Ringash, Jolie; Perkins, Greg; Brierley, James; Lockwood, Gina; Islam, Mohammad; Catton, Pamela; Cummings, Bernard; Kim, John; Wong, Rebecca; Dawson, Laura

    2005-01-01

    Purpose: To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over conformal planning for postoperative adjuvant radiotherapy in patients with gastric carcinoma. Methods and Materials: Twenty patients who had undergone treatment planning with conformal beam arrangements for 4500 cGy adjuvant radiotherapy between 2000 and 2001 underwent repeat planning using IMRT techniques. Conformal five-field plans were compared with seven- to nine-field coplanar sliding-window IMRT plans. For each patient, the cumulative dose-volume histograms and organ-dose summaries (without distributions or digitally reconstructed radiographs) were provided to two independent, 'blinded' GI radiation oncologists. The oncologists indicated which plan provided better planning target volume coverage and critical organ sparing, any safety concerns with either plan, and which plan they would choose to treat the patient. Results: In 18 (90%) of 20 cases, both oncologists chose the same plan. Cases with disagreement were given to a third 'blinded' reviewer. A 'preferred plan' could be determined in 19 (95%) of 20 cases. IMRT was preferred in 17 (89%) of 19 cases. In 4 (20%) of 20 IMRT plans at least one radiation oncologist had safety concerns because of the spinal cord dose (3 cases) or small bowel dose (2 cases). Of 42 ratings, IMRT was thought to provide better planning target volume coverage in 36 (86%) and better sparing of the spinal cord in 31 (74%) of 42, kidneys in 29 (69%), liver in 30 (71%), and heart in 29 (69%) of 42 ratings. The median underdose volume (1.7 vs. 4.1 cm 3 ), maximal dose to the spinal cord (36.85 vs. 45.65 Gy), and dose to 50% of the liver (17.29 vs. 27.97), heart (12.89 vs. 15.50 Gy), and left kidney (15.50 vs. 16.06 Gy) were lower with IMRT than with the conformal plans. Conclusion: Compared with the conformal plans, oncologists frequently preferred IMRT plans when using dose-volume histogram data. The advantages of IMRT plans include both

  3. Sporadic meningioangiomatosis-associated atypical meningioma mimicking parenchymal invasion of brain: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Luo Bo-ning

    2010-06-01

    Full Text Available Abstract Meningioangiomatosis is a rare hamartomatous lesion or meningiovascular malformation in brain. In extremely rare condition, meningioma may occur together with meningioangiomatosis, and only 19 cases have been described in English literature until now. We now report a case of meningioangiomatosis-associated meningioma with atypical and clear cell variant. A 34-year-old man presented a 3-month history of progressive numbness and weakness of his left lower extremity. He had no stigmata of neurofibromatosis type 2. Magnetic resonance imaging (MRI revealed multifocal lesions in the right frontoparietal lobe. The lesions were totally removed. Microscopically, parts of lesions were atypical and clear cell meningioma corresponding to WHO grade II. The adjacent brain parenchyma showed the histological features of meningioangiomatosis. Neoplastic cells in atypical meningioma area were immunoreactive to epithelial membrane antigen (EMA with high MIB-1 index of up to 20%. However, the spindle cells in meningioangiomatosis area were negative for EMA with low MIB-1 index of up to 1%. The diagnosis of atypical meningioma associated with sporadic meningioangiomatosis was made. To our knowledge, this is the first case of a meningioangiomatosis-associated meningioma with atypical and clear cell variant component to be described. The patient had been followed-up for 11 months without adjuvant radiotherapy or chemotherapy. No tumor recurrence was found during this period. Meningioangiomatosis-associated meningioma is more likely to occur in younger patients and histologically to mimic parenchymal invasion of brain. We suggest that postoperative radiotherapy or chemotherapy should be given careful consideration to avoid over-treatment due to erroneously interpret as malignant meningioma.

  4. Improved Correlation of the Neuropathologic Classification According to Adapted World Health Organization Classification and Outcome After Radiotherapy in Patients With Atypical and Anaplastic Meningiomas

    International Nuclear Information System (INIS)

    Combs, Stephanie E.; Schulz-Ertner, Daniela; Debus, Jürgen; Deimling, Andreas von; Hartmann, Christian

    2011-01-01

    Purpose: To evaluate the correlation between the 1993 and 2000/2007 World Health Organization (WHO) classification with the outcome in patients with high-grade meningiomas. Patients and Methods: Between 1985 and 2004, 73 patients diagnosed with atypical or anaplastic meningiomas were treated with radiotherapy. Sections from the paraffin-embedded tumor material from 66 patients (90%) from 13 different pathology departments were re-evaluated according to the first revised WHO classification from 1993 and the revised classifications from 2000/2007. In 4 cases, the initial diagnosis meningioma was not reproducible (5%). Therefore, 62 patients with meningiomas were analyzed. Results: All 62 tumors were reclassified according to the 1993 and 2000/2007 WHO classification systems. Using the 1993 system, 7 patients were diagnosed with WHO grade I meningioma (11%), 23 with WHO grade II (37%), and 32 with WHO grade III meningioma (52%). After scoring using the 2000/2007 system, we found 17 WHO grade I meningiomas (27%), 32 WHO grade II meningiomas (52%), and 13 WHO grade III meningiomas (21%). According to the 1993 classification, the difference in overall survival was not statistically significant among the histologic subgroups (p = .96). Using the 2000/2007 WHO classifications, the difference in overall survival became significant (p = .02). Of the 62 reclassified patients 29 developed tumor progression (47%). No difference in progression-free survival was observed among the histologic subgroups (p = .44). After grading according to the 2000/2007 WHO classifications, significant differences in progression-free survival were observed among the three histologic groups (p = .005). Conclusion: The new 2000/2007 WHO classification for meningiomas showed an improved correlation between the histologic grade and outcome. This classification therefore provides a useful basis to determine the postoperative indication for radiotherapy. According to our results, a comparison of the

  5. Improved Correlation of the Neuropathologic Classification According to Adapted World Health Organization Classification and Outcome After Radiotherapy in Patients With Atypical and Anaplastic Meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephanie E., E-mail: Stephanie.Combs@med.uni-heidelberg.de [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany); Schulz-Ertner, Daniela [Radiologisches Institut, Markuskrankenhaus Frankfurt, Frankfurt am Main (Germany); Debus, Juergen [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany); Deimling, Andreas von; Hartmann, Christian [Department of Neuropathology, Institute for Pathology, University Hospital of Heidelberg, Heidelberg (Germany); Clinical Cooperation Unit Neuropathology, German Cancer Research Center, Heidelberg (Germany)

    2011-12-01

    Purpose: To evaluate the correlation between the 1993 and 2000/2007 World Health Organization (WHO) classification with the outcome in patients with high-grade meningiomas. Patients and Methods: Between 1985 and 2004, 73 patients diagnosed with atypical or anaplastic meningiomas were treated with radiotherapy. Sections from the paraffin-embedded tumor material from 66 patients (90%) from 13 different pathology departments were re-evaluated according to the first revised WHO classification from 1993 and the revised classifications from 2000/2007. In 4 cases, the initial diagnosis meningioma was not reproducible (5%). Therefore, 62 patients with meningiomas were analyzed. Results: All 62 tumors were reclassified according to the 1993 and 2000/2007 WHO classification systems. Using the 1993 system, 7 patients were diagnosed with WHO grade I meningioma (11%), 23 with WHO grade II (37%), and 32 with WHO grade III meningioma (52%). After scoring using the 2000/2007 system, we found 17 WHO grade I meningiomas (27%), 32 WHO grade II meningiomas (52%), and 13 WHO grade III meningiomas (21%). According to the 1993 classification, the difference in overall survival was not statistically significant among the histologic subgroups (p = .96). Using the 2000/2007 WHO classifications, the difference in overall survival became significant (p = .02). Of the 62 reclassified patients 29 developed tumor progression (47%). No difference in progression-free survival was observed among the histologic subgroups (p = .44). After grading according to the 2000/2007 WHO classifications, significant differences in progression-free survival were observed among the three histologic groups (p = .005). Conclusion: The new 2000/2007 WHO classification for meningiomas showed an improved correlation between the histologic grade and outcome. This classification therefore provides a useful basis to determine the postoperative indication for radiotherapy. According to our results, a comparison of the

  6. SU-F-T-590: Modeling PTV Dose Fall-Off for Cervical Cancer SBRT Treatment Planning Using VMAT and Step-And-Shoot IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, A Brito; Cohen, D; Eng, T; Gutierrez, A [University of Texas Health Science Center San Antonio, San Antonio, TX (United States)

    2016-06-15

    Purpose: Due to the high dose per fraction in SBRT, dose conformity and dose fall-off are critical. In patients with cervical cancer, rapid dose fall-off is particularly important to limit dose to the nearby rectum, small bowel, and bladder. This study compares the target volume dose fall-off for two radiation delivery techniques, fixed-field IMRT & VMAT, using non-coplanar beam geometries. Further comparisons are made between 6 and 10MV photon beam energies. Methods: Eleven (n=11) patients were planned in Pinnacle3 v9.10 with a NovalisTx (HD120 MLC) machine model using 6 and 10 MV photons. The following three techniques were used: (1) IMRT (10 non-coplanar beams) (2) Dual, coplanar 360° VMAT arcs (4° spacing), and (3) Triple, non-coplanar VMAT arcs (1 full arc and dual partial arcs). All plans were normalized such that 98% of the PTV received at least 28Gy/4Fx. Dose was calculated using a 2.0mm isotropic dose grid. To assess dose fall-off, twenty concentric 2mm thick rings were created around the PTV. The maximum dose in each ring was recorded and the data was fitted to model dose fall-off. A separate analysis was performed by separating target volumes into small (0–50cc), medium (51–80cc), and large (81–110cc). Results: Triple, non-coplanar VMAT arcs showed the best dose fall-off for all patients evaluated. All fitted regressions had an R{sup 2}≥0.99. At 10mm from the PTV edge, 10 MV VMAT3-arc had an absolute improvement in dose fall-off of 3.8% and 6.9% over IMRT and VMAT2-arc, respectively. At 30mm, 10 MV VMAT3-arc had an absolute improvement of 12.0% and 7.0% over IMRT and VMAT2-arc, respectively. Faster dose fall-off was observed for small volumes as opposed to medium and large ones—9.6% at 20mm. Conclusion: Triple, non-coplanar VMAT arcs offer the sharpest dose fall-off for cervical SBRT plans. This improvement is most pronounced when treating smaller target volumes.

  7. MUST ONCOLOGICAL PRINCIPLES BE IN THE SURGERY OF MENINGIOMAS? EN BLOC REMOVAL OF GIANT RIGHT FRONTAL MENINGIOMA WITH EXTRACRANIAL SPREAD. DESCRIPTION OF A CLINICAL CASE

    Directory of Open Access Journals (Sweden)

    V. B. Karakhan

    2014-01-01

    Full Text Available The use of the oncological principle – en bloc ablastic tumor resection – can expect a breakthrough in the treatment of baseline unfavorable patient groups. In the described case of atypical meningioma, its en bloc resection presents significant technical difficulties when accomplishing the task associated with the giant sizes of a tumor as an iceberg growing outside and into the cranial cavity, its rich vascularization from both the internal and external carotid artery system, with the involvement of the superior sagittal sinus, the presence of a dense bone crown that combines the three-component construction of a neoplasm, which made difficult safe mobilization and scanning in the cranial cavity.In such topographic variants, the criteria for the Simpson radical meningioma resection are inapplicable and only en bloc tumor resection may reflect the oncological principles of surgery. The technologies of en bloc resection of intracranial meningiomas should be more frequently used because preoperative neurovisualization and even histological diagnosis does not always allow the grade of meningiomas to be specified.

  8. A two isocenter IMRT technique with a controlled junction dose for long volume targets

    International Nuclear Information System (INIS)

    Zeng, G G; Heaton, R K; Catton, C N; Chung, P W; O'Sullivan, B; Lau, M; Parent, A; Jaffray, D A

    2007-01-01

    Most IMRT techniques have been designed to treat targets smaller than the field size of conventional linac accelerators. In order to overcome the field size restrictions in applying IMRT, we developed a two isocenter IMRT technique to treat long volume targets. The technique exploits an extended dose gradient throughout a junction region of 4-6 cm to minimize the impact of field match errors on a junction dose and manipulates the inverse planning and IMRT segments to fill in the dose gradient and achieve dose uniformity. Techniques for abutting both conventional fields with IMRT ('Static + IMRT') and IMRT fields ('IMRT + IMRT') using two separate isocenters have been developed. Five long volume sarcoma cases have been planned in Pinnacle (Philips, Madison, USA) using Elekta Synergy and Varian 2100EX linacs; two of the cases were clinically treated with this technique. Advantages were demonstrated with well-controlled junction target uniformity and tolerance to setup uncertainties. The junction target dose heterogeneity was controlled at a level of ±5%; for 3 mm setup errors at the field edges, the junction target dose changed less than 5% and the dose sparing to organs at risk (OARs) was maintained. Film measurements confirmed the treatment planning results

  9. Craniospinal treatment with IMRT multi-isocentric and image-guided linear accelerator based on Gantry; Tratamiento craneoespinal multi-isocentrico con IMRT y guiado por imagen en acelerador lineal basado en Gantry

    Energy Technology Data Exchange (ETDEWEB)

    Sanz Beltran, M.; Caballero Perea, B.; Rodriguez Rodriguez, C.; Arminio Diaz, E.; Lopez Fernandez, A.; Gomez Fervienza, J. R.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.; Gomez Fervienza, J. r.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.

    2011-07-01

    The objective is the realization of craniospinal treatment with a linear accelerator equipped with gantry based on MLC, carbon fiber table and Image Guided capability. The great length of treatment (patient l, 80m in height) was a great difficulty for want of full length of the longitudinal movement of the table to adequately cover the PTV, plus free metallic screws fastening the head of the table extender preventing further incidents.

  10. Stereological estimation of nuclear mean volume in invasive meningiomas

    DEFF Research Database (Denmark)

    Madsen, C; Schrøder, H D

    1996-01-01

    A stereological estimation of nuclear mean volume in bone and brain invasive meningiomas was made. For comparison the nuclear mean volume of benign meningiomas was estimated. The aim was to investigate whether this method could discriminate between these groups. We found that the nuclear mean...... volume in the bone and brain invasive meningiomas was larger than in the benign tumors. The difference was significant and moreover it was seen that there was no overlap between the two groups. In the bone invasive meningiomas the nuclear mean volume appeared to be larger inside than outside the bone....... No significant difference in nuclear mean volume was found between brain and bone invasive meningiomas. The results demonstrate that invasive meningiomas differ from benign meningiomas by an objective stereological estimation of nuclear mean volume (p

  11. Conformal intensity-modulated radiotherapy (IMRT) delivered by robotic linac - testing IMRT to the limit?

    International Nuclear Information System (INIS)

    Webb, S.

    1999-01-01

    In this paper it is proposed that intensity-modulated radiotherapy (IMRT) could be delivered optimally by a short-length linac mounted on a robotic arm. The robot would allow the linac to 'plant' narrow pencils of photon radiation with any orientation (excluding zones within which the linac and couch might collide) relative to the planning target volume (PTV). The treatment is specified by the trajectory of the robot and by the number of monitor units (MUs) delivered at each robotic orientation. An inverse-planning method to determine the optimum robotic trajectory is presented. It is shown that for complex PTVs, specifically those with concavities in their outline, the conformality of the treatment is improved by the use of a complex trajectory in comparison with a less complex constrained trajectory and this improvement is quantified. It is concluded that robotic linac delivery would lead to a great flexibility in those IMRT treatments requiring very complicated dose distributions with complex 3D shapes. However, even using very fast computers, the goal of determining whether robotic linac delivery is the ultimate IMRT cannot be conclusively reached at present. (author)

  12. Automatically gated image-guided breath-hold IMRT is a fast, precise, and dosimetrically robust treatment for lung cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Simeonova-Chergou, Anna; Jahnke, Anika; Siebenlist, Kerstin; Stieler, Florian; Mai, Sabine; Boda-Heggemann, Judit; Wenz, Frederik; Lohr, Frank; Jahnke, Lennart [University Medical Center Mannheim, University of Heidelberg, Department of Radiotherapy and Oncology, Mannheim (Germany)

    2016-03-15

    High-dose radiotherapy of lung cancer is challenging. Tumors may move by up to 2 cm in craniocaudal and anteroposterior directions as a function of breathing cycle. Tumor displacement increases with treatment time, which consequentially increases the treatment uncertainty. This study analyzed whether automatically gated cone-beam-CT (CBCT)-controlled intensity modulated fast deep inspiration breath hold (DIBH) stereotactic body radiation therapy (SBRT) in flattening filter free (FFF) technique and normofractionated lung DIBH intensity-modulated radiotherapy (IMRT)/volumetric-modulated arc therapy (VMAT) treatments delivered with a flattening filter can be applied with sufficient accuracy within a clinically acceptable timeslot. Plans of 34 patients with lung tumors were analyzed. Of these patients, 17 received computer-controlled fast DIBH SBRT with a dose of 60 Gy (5 fractions of 12 Gy or 12 fractions of 5 Gy) in an FFF VMAT technique (FFF-SBRT) every other day and 17 received conventional VMAT with a flattening filter (conv-VMAT) and 2-Gy daily fractional doses (cumulative dose 50-70 Gy). FFF-SBRT plans required more monitor units (MU) than conv-VMAT plans (2956.6 ± 885.3 MU for 12 Gy/fraction and 1148.7 ± 289.2 MU for 5 Gy/fraction vs. 608.4 ± 157.5 MU for 2 Gy/fraction). Total treatment and net beam-on times were shorter for FFF-SBRT plans than conv-VMAT plans (268.0 ± 74.4 s vs. 330.2 ± 93.6 s and 85.8 ± 25.3 s vs. 117.2 ± 29.6 s, respectively). Total slot time was 13.0 min for FFF-SBRT and 14.0 min for conv-VMAT. All modalities could be delivered accurately despite multiple beam-on/-off cycles and were robust against multiple interruptions. Automatically gated CBCT-controlled fast DIBH SBRT in VMAT FFF technique and normofractionated lung DIBH VMAT can be applied with a low number of breath-holds in a short timeslot, with excellent dosimetric accuracy. In clinical routine, these approaches combine optimally reduced lung tissue irradiation with maximal

  13. Experience Using DosimetryCheck software for IMRT and RapidArc Patient Pre-treatment QA and a New Feature for QA during Treatment

    International Nuclear Information System (INIS)

    Pinkerton, Arthur; Hannon, Michael; Kwag, Jae; Renner, Wendel Dean

    2010-01-01

    We have used the DosimetryCheck program with the EPID's on our Varian 2100EX's to perform pre-treatment QA on more than 350 patients, between the last quarter of 2006 and the present. The software uses the EPID measured fluences of the treatment fields to reconstruct the dose distribution in the CT planning model of the patient. Since the dose calculation algorithm, is different from that used by our Eclipse planning system, this provides an independent check of planning accuracy as well as treatment delivery. 2D and 3D dose distributions, point doses, Gamma distributions, DVH statistics and MU calculations can be compared. Absolute differences of Reference Point doses between Dosimetry Check and Eclipse average 1.20%, which is similar to the ionization chamber dose differences of 1.29% for the same patient verification plans. Examples of cases for various treatment sites and delivery modes will be presented. A Special Report in Medical Physics Vol. 37 Number 6 Pg. 2638-2644 from Mans et al at The Netherlands Cancer Institute demonstrated the ability of in vivo EPID dosimetry to detect treatment errors, that escaped other QA checks. A new version of DosimetryCheck awaiting FDA approval, is capable of successfully reconstructing the dose distribution in the patient from the EPID measured exit fluences. This can also be applied to CBCT images providing actual patient dose verification for a treatment session. This should be particularly useful for monitoring hypo-fractionated treatment regimens. Examples of this method will also be presented.

  14. Dosimetric validation of planning system Eclipse 10 in partial breast irradiation treatments with IMRT; Validacion dosimetrica del sistema de planeacion Eclipse 10 en tratamientos de irradiacion parcial de mama con IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez T, J. J.; Gutierrez M, J. G.; Ortiz A, C. S.; Chagoya G, A.; Gutierrez C, J. G., E-mail: jvelaesfm@gmail.com [Centro Medico Nacional Siglo XXI, Hospital de Oncologia, Departamentos de Fisica Medica y Radioterapia, Av. Cuauhtemoc 330, 03020 Mexico D. F. (Mexico)

    2015-10-15

    Partial breast irradiation is a new type of external radiation therapy to treat breast cancer in early clinical stages. Consist of administering to the channel surgical high doses of radiation in few treatment sessions. In this paper the dose calculations of the planning system Eclipse version 10 for a treatment of partial breast irradiation with X-rays beams (6 MV) intensity modulated were compared against the measurements made with OSL dosimeters and radio-chromic dye film. An anthropomorphic mannequin was used in which OSL dosimeters were collocated near the surface, an inside the radio-chromic dye film one plate; with this latest one dimensional dose distribution was measured. Previously dosimeters were calibrated irradiating them with a beam of X-rays 6 MV under the conditions specified in the IAEA-398 protocol. The OSL dosimeters were read in the Micro star Landauer equipment, the radio-chromic dye films were read with a scanner Epson 10000-Xl and analyzed with FilmCal and PTW Verisoft programs. The differences between measured and calculated dose were as follows: 3.6±1% for the OSL dosimeter and 96.3±1% of the analyzed points approved the gamma index criterion (3%, 3m m) when comparing the matrices of calculated dose and measured with the radio-chromic dye film. These results confirm the good dosimetric performance of planning system used under specific conditions used in the partial breast irradiation technique. (Author)

  15. An IMRT dose distribution study using commercial verification software

    International Nuclear Information System (INIS)

    Grace, M.; Liu, G.; Fernando, W.; Rykers, K.

    2004-01-01

    Full text: The introduction of IMRT requires users to confirm that the isodose distributions and relative doses calculated by their planning system match the doses delivered by their linear accelerators. To this end the commercially available software, VeriSoft TM (PTW-Freiburg, Germany) was trialled to determine if the tools and functions it offered would be of benefit to this process. The CMS Xio (Computer Medical System) treatment planning system was used to generate IMRT plans that were delivered with an upgraded Elekta SL15 linac. Kodak EDR2 film sandwiched in RW3 solid water (PTW-Freiburg, Germany) was used to measure the IMRT fields delivered with 6 MV photons. The isodose and profiles measured with the film generally agreed to within ± 3% or ± 3 mm with the planned doses, in some regions (outside the IMRT field) the match fell to within ± 5%. The isodose distributions of the planning system and the film could be compared on screen and allows for electronic records of the comparison to be kept if so desired. The features and versatility of this software has been of benefit to our IMRT QA program. Furthermore, the VeriSoft TM software allows for quick and accurate, automated planar film analysis.Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  16. Poster - Thur Eve - 29: Detecting changes in IMRT QA using statistical process control.

    Science.gov (United States)

    Drever, L; Salomons, G

    2012-07-01

    Statistical process control (SPC) methods were used to analyze 239 measurement based individual IMRT QA events. The selected IMRT QA events were all head and neck (H&N) cases with 70Gy in 35 fractions, and all prostate cases with 76Gy in 38 fractions planned between March 2009 and 2012. The results were used to determine if the tolerance limits currently being used for IMRT QA were able to indicate if the process was under control. The SPC calculations were repeated for IMRT QA of the same type of cases that were planned after the treatment planning system was upgraded from Eclipse version 8.1.18 to version 10.0.39. The initial tolerance limits were found to be acceptable for two of the three metrics tested prior to the upgrade. After the upgrade to the treatment planning system the SPC analysis found that the a priori limits were no longer capable of indicating control for 2 of the 3 metrics analyzed. The changes in the IMRT QA results were clearly identified using SPC, indicating that it is a useful tool for finding changes in the IMRT QA process. Routine application of SPC to IMRT QA results would help to distinguish unintentional trends and changes from the random variation in the IMRT QA results for individual plans. © 2012 American Association of Physicists in Medicine.

  17. Medial Cranial Fossa Meningioma Diagnosed as Mixed Anxiety Disorder with Dissociative Symptoms and Vertigo

    Directory of Open Access Journals (Sweden)

    Emin Mehmet Ceylan

    2016-01-01

    Full Text Available Meningiomas are mostly benign tumors of the meninges that may stay clinically silent or present first with psychiatric symptoms only. We present a case of medial cranial fossa meningioma that was first diagnosed as mixed anxiety disorder with dissociative symptoms and vertigo. In light of the intact neurological and vestibular system examination, our patient’s vertigo and depersonalization were firstly addressed as psychosomatic symptoms of the psychiatric syndrome. Despite decreased anxiety and improved mood, dissociative symptoms and vertigo were resistant to treatment which prompted further research yielding a left hemisphere localized meningioma. Resection of meningioma resulted in full remission of the patient proving it to be responsible for the etiology of the psychiatric syndrome and vertigo. We suggest that brain imaging should be performed for patients with late-onset (>50 years psychiatric symptoms and those with treatment resistance. It is important to keep in mind always that medically unexplained symptoms may become explicable with detailed assessment and regular follow-up of the patient.

  18. Meningioma of Foramen Magnum Causing Drop Attacks

    Directory of Open Access Journals (Sweden)

    Amit Mahore

    2015-01-01

    Full Text Available A 52-year-old female presented with frequent episodes of falls without loss of consciousness. These episodes lasted for brief period followed by full neurological recovery. Magnetic resonance imaging (MRI of the brain showed foramen magnum meningioma encasing left vertebral artery. The patient had dramatic improvement after excision of the tumor.

  19. Analysis of peritumoral cerebral edema of meningiomas

    International Nuclear Information System (INIS)

    Okada, Masaaki; Tanaka, Katsuyuki; Abe, Juzo; Sekino, Hiroaki; Ogawa, Takei; Hayashi, Tatsuo.

    1992-01-01

    Peritumoral edema associated with 28 meningiomas was studied. The results of radiological investigation, using MRI, CT, and angiography, and histological studies were described and correlated with each other in order to clarify the mechanism of peritumoral cerebral edema production. Extensive peritumoral edema was recognized when the venous sinus or cortical veins, especially the superficial and deep Sylvian veins, were invaded and/or compressed markedly by the tumor. Therefore, large tumors (more than 5 cm in diameter) which were located in the parasagittal area and the middle cranial fossa had a tendency to be associated with extensive peritumoral edema. The posterior fossa meningiomas were associated with small edema because there were rich venous channels in the posterior fossa. Although there have been several reports that the peritumoral edema of meningioma would be produced by the vessels of the tumor itself and would migrate through the tumor capsule into the surrounding brain tissue, and although mechanical factors alone are not sufficient to explain peritumoral edema production, we would like to postulate that the longstanding mechanical compression of venous circulation by the meningioma might be an important factor in the production of the peritumoral cerebral edema. (author)

  20. Natural history of intracranial meningioma after radiotherapy

    International Nuclear Information System (INIS)

    Monzen, Yoshio

    1999-01-01

    The author examined the natural history of intracranial meningioma after radiotherapy using CT or MR imaging. Twenty patients with intracranial meningioma received radiotherapy from a high-energy linear accelerator (4-10 MV X rays) from 1980 to 1996. The total doses were 50 Gy to the tumor bed in single doses of 2 Gy in 5 weekly fractions. Meningiomas in 10 of 20 patients were reduced within 1 to 38 months after radiotherapy, the average being 11 months. The tumors were controlled for a median of 60 months after radiotherapy (range 19-126 months). Four other patients have shown no change in tumor size after radiotherapy. The tumors were controlled for a median of 70 months after radiotherapy (range 37-127 months). The other six patients have shown tumor growth within 3 to 25 months after radiotherapy, after which the tumors stopped growing for a median of 71 months (range 2-181 months). Neither tumor size nor histological type was related to response. The growth of tumors was controlled by radiotherapy for a median duration of 43 months in the meningothelial type, 52 months in the fibroblastic type, and 61 months in the transitional type. The median duration for all benign tumors was 52 months. A moderate correlation was noted between tumor response and functional outcome after radiotherapy in 9 patients with neurological deficits. The natural histories of intracranial meningiomas after radiotherapy were grouped into three categories. Some tumors showed no change in size over a long period. This was a characteristic response after radiotherapy that differed from that of other brain tumors. The results of this study provide important information for the follow-up of intracranial meningiomas after radiotherapy. (author)

  1. Meningiomas, dicentric chromosomes, gliomas, and telomerase activity.

    Science.gov (United States)

    Carroll, T; Maltby, E; Brock, I; Royds, J; Timperley, W; Jellinek, D

    1999-08-01

    Lack of telomere maintenance during cell replication leads to telomere erosion and loss of function. This can result in telomere associations which probably cause the dicentric chromosomes seen in some tumour cells. One mechanism of telomere maintenance in dividing cells is the action of telomerase, a ribonucleoprotein enzyme that adds TTAGGG repeats onto telomeres and compensates for their shortening during cell division. Over 90 per cent of extracranial malignant neoplasms have been found to have telomerase activity. This study sought to determine if there was a relationship between absence of telomerase activity and presence of dicentric chromosomes in meningiomas and to what extent the other main group of central nervous system tumours, the gliomas, expressed telomerase activity. Telomerase activity was measured on 25 meningiomas and 29 gliomas. Four of the meningiomas were atypical variants and 11 were positive for dicentric chromosomes. Twenty-five of 29 gliomas were glioblastoma multiforme tumours. Measures were taken to ensure absence of false positives due to primer-dimer interaction and false negatives due to protein degradation or the presence of Taq polymerase inhibitors. All 25 meningiomas and the four low-grade gliomas (WHO grade II) were telomerase activity-negative. Seven (28 per cent) of the 25 glioblastoma multiforme tumours showed telomerase activity. The absence of telomerase activity in meningiomas and the high frequency of telomere associations support the hypothesis that these tumours are benign, transformed but pre-crisis. The relatively low frequency of telomerase activity in the malignant glioblastoma multiforme suggests that most of these tumours may have other mechanisms of telomere maintenance and that the potentially therapeutic telomerase inhibitors will not be of great value in the future management of the majority of patients suffering from these tumours. Copyright 1999 John Wiley & Sons, Ltd.

  2. Surviving Hypopharynx-Larynx Carcinoma in the Era of IMRT

    International Nuclear Information System (INIS)

    Studer, Gabriela; Peponi, Evangelia; Kloeck, Stephan; Dossenbach, Thomas; Huber, Gerhard; Glanzmann, Christoph

    2010-01-01

    Purpose: Outcome in locoregionally advanced laryngeal carcinoma and hypopharyngeal carcinoma after conventional radiation techniques is known for modest disease control and considerable late toxicity. Considering the lack of standardization in prescription dose for intensity-modulated radiotherapy (IMRT), we aimed to compare the results after our methods of simultaneously integrated boost IMRT with published results. Methods and Materials: Between March 2002 and December 2008, 65 hypopharyngeal, 31 supraglottic, and 27 locoregionally advanced glottic tumor patients underwent definitive IMRT (with simultaneous chemotherapy in 86%). Of these, 64% presented with locoregionally advanced disease. Mean follow-up was 26 months (range, 3-83 months), with a median of 21 months. Treatment (2.0-2.2Gy per fraction, 66-72.6Gy) followed a prospectively defined protocol. If the boost volume included more than half of the larynx or a substantial part of the pharynx, dose was limited to 2.0Gy per fraction. Results: The 2-year local, nodal, and locoregional control (LRC) rates for the entire cohort were 82%, 90%, and 77%, respectively; the disease-free and overall survival rates were 75% and 83%, respectively. The ultimate 2-year LRC rate, including salvage surgery, was 86%. Laryngectomy was required in 2 LRC patients needing tracheostoma already before; 2 further LRC patients needed tracheostomy before IMRT and remained tracheostoma dependent, and 3 patients remained feeding tube dependent after IMRT. Salvage laryngectomy was successful in 8 of 11. Of all 123 patients, 91 patients (74%) are locoregionally controlled and live with a functional laryngopharynx. Conclusions: Simultaneously integrated boost IMRT with limited acceptance of dose inhomogeneity resulted in very satisfactory disease control despite a slight left shift of planning target volume curves on the dose-volume histogram. Considering the treatment tolerance, a careful increase in dose in our patients seems possible

  3. Meningioma growth and interferon beta-1b treated multiple sclerosis: coincidence or relationship?

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, A.; Xinou, E. [AHEPA University Hospital, Aristotele University School of Medicine, Department of Radiology, Thessaloniki (Greece); Karacostas, D.; Parissis, D.; Milonas, I. [AHEPA University Hospital, Aristotele University School of Medicine, B' Department of Neurology, Thessaloniki (Greece); Karkavelas, G. [AHEPA University Hospital, Aristotele University School of Medicine, Laboratory of Pathology, Thessaloniki (Greece)

    2005-07-01

    Although the coincidence of multiple sclerosis (MS) and central nervous system (CNS) tumors has been reported in over 30 cases in English literature, meningioma growth was associated with interferon-beta (INF-b) treated MS only in two of them. We report the case of a 19-year-old woman with clinically possible, laboratory supported MS, and a concomitant right intraventricular tumor with magnetic resonance imaging (MRI) characteristics consistent with meningioma (similar signal with grey matter on T1 and T2-weighted images and homogenous, intense enhancement). Two years after initiation of INF-b treatment, follow-up brain MRI revealed enlargement of the intraventricular mass and relative increase in the number of white matter lesions without significant clinical deterioration. She underwent almost total resection of the mass and histology confirmed the diagnosis of papillary meningioma. Based on the immunohistochemistry results, we speculate that INF-b resulted in meningioma growth by enhancing platelet derived growth factor (PDGF) receptors or/and down-regulating transforming growth factor receptors on the tumor itself. (orig.)

  4. Meningioma growth and interferon beta-1b treated multiple sclerosis: coincidence or relationship?

    International Nuclear Information System (INIS)

    Drevelegas, A.; Xinou, E.; Karacostas, D.; Parissis, D.; Milonas, I.; Karkavelas, G.

    2005-01-01

    Although the coincidence of multiple sclerosis (MS) and central nervous system (CNS) tumors has been reported in over 30 cases in English literature, meningioma growth was associated with interferon-beta (INF-b) treated MS only in two of them. We report the case of a 19-year-old woman with clinically possible, laboratory supported MS, and a concomitant right intraventricular tumor with magnetic resonance imaging (MRI) characteristics consistent with meningioma (similar signal with grey matter on T1 and T2-weighted images and homogenous, intense enhancement). Two years after initiation of INF-b treatment, follow-up brain MRI revealed enlargement of the intraventricular mass and relative increase in the number of white matter lesions without significant clinical deterioration. She underwent almost total resection of the mass and histology confirmed the diagnosis of papillary meningioma. Based on the immunohistochemistry results, we speculate that INF-b resulted in meningioma growth by enhancing platelet derived growth factor (PDGF) receptors or/and down-regulating transforming growth factor receptors on the tumor itself. (orig.)

  5. Indocyanine green videoangiography (ICGV)-guided surgery of parasagittal meningiomas occluding the superior sagittal sinus (SSS).

    Science.gov (United States)

    d'Avella, Elena; Volpin, Francesco; Manara, Renzo; Scienza, Renato; Della Puppa, Alessandro

    2013-03-01

    Maximal safe resection is the goal of correct surgical treatment of parasagittal meningiomas, and it is intimately related to the venous anatomy both near and directly involved by the tumor. Indocyanine green videoangiography (ICGV) has already been advocated as an intra-operative resourceful technique in brain tumor surgery for the identification of vessels. The aim of this study was to investigate the role of ICGV in surgery of parasagittal meningiomas occluding the superior sagittal sinus (SSS). In this study, we prospectively analyzed clinical, radiological and intra-operative findings of patients affected by parasagittal meningioma occluding the SSS, who underwent ICGV assisted-surgery. Radiological diagnosis of complete SSS occlusion was pre-operatively established in all cases. ICGV was performed before dural opening, before and during tumor resection, at the end of the procedure. Five patients were included in our study. In all cases, ICGV guided dural opening, tumor resection, and venous management. The venous collateral pathway was easily identified and preserved in all cases. Radical resection was achieved in four cases. Surgery was uneventful in all cases. Despite the small number of patients, our study shows that ICG videoangiography could play a crucial role in guiding surgery of parasagittal meningioma occluding the SSS. Further studies are needed to define the role of this technique on functional and oncological outcome of these patients.

  6. Comparison of dental health of patients with head and neck cancer receiving IMRT vs conventional radiation.

    Science.gov (United States)

    Duarte, Victor M; Liu, Yuan F; Rafizadeh, Sassan; Tajima, Tracey; Nabili, Vishad; Wang, Marilene B

    2014-01-01

    To analyze the dental health of patients with head and neck cancer who received comprehensive dental care after intensity-modulated radiation therapy (IMRT) compared with radiation therapy (RT). Historical cohort study. Veteran Affairs (VA) hospital. In total, 158 patients at a single VA hospital who were treated with RT or IMRT between 2003 and 2011 were identified. A complete dental evaluation was performed prior to radiation treatment, including periodontal probing, tooth profile, cavity check, and mobility. The dental treatment plan was formulated to eliminate current and potential dental disease. The rates of dental extractions, infections, caries, mucositis, xerostomia, and osteoradionecrosis (ORN) were analyzed, and a comparison was made between patients treated with IMRT and those treated with RT. Of the 158 patients, 99 were treated with RT and 59 were treated with IMRT. Compared with those treated with IMRT, significantly more patients treated with RT exhibited xerostomia (46.5% vs 16.9%; P radiation treatment (32.2% vs 11.1%; P = .002; OR, 3.8; 95% CI, 1.65-8.73). Patients who were treated with IMRT had fewer instances of dental disease, more salivary flow, and fewer requisite posttreatment extractions compared with those treated with RT. The number of posttreatment extractions has been reduced with the advent of IMRT and more so with a complete dental evaluation prior to treatment.

  7. Preformed titanium cranioplasty after resection of skull base meningiomas - a technical note.

    Science.gov (United States)

    Schebesch, Karl-Michael; Höhne, Julius; Gassner, Holger G; Brawanski, Alexander

    2013-12-01

    Meningiomas of the fronto-basal skull are difficult to manage as the treatment usually includes extensive resection of the lesion, consecutive reconstruction of the meninges and of the skull. Especially after removal of spheno-orbital and sphenoid-wing meningiomas, the cosmetic result is of utmost importance. In this technical note, we present our institutional approach in the treatment of skull base meningiomas, focussing on the reconstruction of the neurocranium with individually preformed titanium cranioplasty (CRANIOTOP(®), CL Instruments, Germany). Two female patients (40 years, 64 years) are presented. Both patients presented with skull base lesions suggestive of meningiomas. The preoperative thin-sliced CT scan was processed to generate a 3D-model of the skull. On it, the resection was mapped and following a simulated resection, the cranioplasty was manufactured. Intra-operatively, the titanium plate served as a template for the skull resection and was implanted after microsurgical tumour removal, consecutively. The cosmetic result was excellent. Immediate postoperative CT scan revealed accurate fitting and complete tumour removal. Control Magnetic Resonance Imaging (MRI) within 12 weeks was possible without any artifacts. The comprehensive approach described indicates only one surgical procedure for tumour removal and for reconstruction of the skull. The titanium plate served as an exact template for complete resection of the osseous parts of the tumour. Cosmetic outcome was excellent and control MRI was possible post operatively. CRANIOTOP(®) cranioplasty is a safe and practical tool for reconstruction of the skull after meningioma surgery. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  8. Atypical olfactory groove meningioma associated with uterine fibromatosis; case report

    Directory of Open Access Journals (Sweden)

    Toma I. Papacocea

    2016-11-01

    Full Text Available The concomitant presence of the olfactory groove meningioma with uterine fibrosis is very rare. Our report presents the case of a giant olfactory groove meningioma revealed after a uterine fibroma resection in a 44 years-old female, due to a generalized seizure 10 days after operation. Cranial CT-scan identified the tumor as an olfactory groove meningioma. The tumor was operated with a macroscopically complete resection; the endothermal coagulation of the dura attachment was performed (Simpson II with a good postoperative evolution. Laboratory results showed the presence of receptors for steroid hormones both in meningioma and uterine tumor, and the histopathological examination revealed an atypical meningioma with 17% proliferation markers. Our findings suggest that even though meningiomas are benign tumors and a complete resection usually indicates a good prognosis, the association with uterine fibromatosis and the presence of high percentage of steroid receptors creates a higher risk to relapse, imposing therefore a good monitoring.

  9. Coverage-based constraints for IMRT optimization

    Science.gov (United States)

    Mescher, H.; Ulrich, S.; Bangert, M.

    2017-09-01

    Radiation therapy treatment planning requires an incorporation of uncertainties in order to guarantee an adequate irradiation of the tumor volumes. In current clinical practice, uncertainties are accounted for implicitly with an expansion of the target volume according to generic margin recipes. Alternatively, it is possible to account for uncertainties by explicit minimization of objectives that describe worst-case treatment scenarios, the expectation value of the treatment or the coverage probability of the target volumes during treatment planning. In this note we show that approaches relying on objectives to induce a specific coverage of the clinical target volumes are inevitably sensitive to variation of the relative weighting of the objectives. To address this issue, we introduce coverage-based constraints for intensity-modulated radiation therapy (IMRT) treatment planning. Our implementation follows the concept of coverage-optimized planning that considers explicit error scenarios to calculate and optimize patient-specific probabilities q(\\hat{d}, \\hat{v}) of covering a specific target volume fraction \\hat{v} with a certain dose \\hat{d} . Using a constraint-based reformulation of coverage-based objectives we eliminate the trade-off between coverage and competing objectives during treatment planning. In-depth convergence tests including 324 treatment plan optimizations demonstrate the reliability of coverage-based constraints for varying levels of probability, dose and volume. General clinical applicability of coverage-based constraints is demonstrated for two cases. A sensitivity analysis regarding penalty variations within this planing study based on IMRT treatment planning using (1) coverage-based constraints, (2) coverage-based objectives, (3) probabilistic optimization, (4) robust optimization and (5) conventional margins illustrates the potential benefit of coverage-based constraints that do not require tedious adjustment of target volume objectives.

  10. Stereological estimation of nuclear volume in benign and atypical meningiomas

    DEFF Research Database (Denmark)

    Madsen, C; Schrøder, H D

    1993-01-01

    A stereological estimation of nuclear volume in benign and atypical meningiomas was made. The aim was to investigate whether this method could discriminate between these two meningeal neoplasms. The difference was significant and it was moreover seen that there was no overlap between the two groups....... The results demonstrate that atypical meningiomas can be distinguished from benign meningiomas by an objective stereological estimation of nuclear volume....

  11. Epilepsy and adverse quality of life in surgically resected meningioma.

    Science.gov (United States)

    Tanti, M J; Marson, A G; Jenkinson, M D

    2017-09-01

    Meningiomas are common intracranial tumors, and despite surgery or therapy with anti-epileptic drugs (AEDs), many patients suffer from seizures. Epilepsy has a significant impact on quality of life (QoL) in non-tumor populations, but the impact of epilepsy on QoL in patients with meningioma is unknown. Our aim was to evaluate the impact of epilepsy on QoL in patients that have undergone resection of a benign meningioma. We recruited meningioma patients without epilepsy (n=109), meningioma patients with epilepsy (n=56), and epilepsy patients without meningioma (n=64). QoL was measured with the Short Form 36 version 2 (SF-36), the Functional Assessment of Cancer Therapy (FACT-BR), and the Liverpool Adverse Events Profile (LAEP). Regression analyses identified significant determinants of QoL. Patients with meningioma and epilepsy had poorer QoL scores than meningioma patients without epilepsy in all measures. In FACT-BR, this difference was significant. Multiple regression analyses demonstrated that current AED use had a greater impact on QoL scores than recent seizures. Other variables associated with impaired QoL included depression, unemployment, and meningioma attributed symptoms. Epilepsy has a negative impact on quality of life in patients with benign meningioma. AED use is correlated with impaired QoL and raised LAEP scores, suggesting that AEDs and adverse effects may have led to impaired QoL in our meningioma patients with epilepsy. The severity of epilepsy in our meningioma population was comparatively mild; therefore, a more conservative approach to AED therapy may be indicated in an attempt to minimize adverse effects. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Preoperative subtyping of meningiomas by perfusion MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [University Medical Center Groningen, University of Groningen (Netherlands); Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China); Department of Radiology, University of Groningen (Netherlands); Roediger, Lars A.; Oudkerk, Matthijs [University Medical Center Groningen, University of Groningen (Netherlands); Department of Radiology, University of Groningen (Netherlands); Shen, Tianzhen [Fudan University Huashan Hospital, Department of Radiology, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China)

    2008-10-15

    This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Thirty-seven meningiomas with peritumoral edema (15 meningothelial, ten fibrous, four angiomatous, and eight anaplastic) underwent perfusion MR imaging by using a gradient echo echo-planar sequence. The maximal rCBV (compared with contralateral normal white matter) in both tumoral parenchyma and peritumoral edema of each tumor was measured. The mean rCBVs of each two histological subtypes were compared using one-way analysis of variance and least significant difference tests. A p value less than 0.05 indicated a statistically significant difference. The mean rCBV of meningothelial, fibrous, angiomatous, and anaplastic meningiomas in tumoral parenchyma were 6.93{+-}3.75, 5.61{+-}4.03, 11.86{+-}1.93, and 5.89{+-}3.85, respectively, and in the peritumoral edema 0.87{+-}0.62, 1.38{+-}1.44, 0.87{+-}0.30, and 3.28{+-}1.39, respectively. The mean rCBV in tumoral parenchyma of angiomatous meningiomas and in the peritumoral edema of anaplastic meningiomas were statistically different (p<0.05) from the other types of meningiomas. Perfusion MR imaging can provide useful functional information on meningiomas and help in the preoperative diagnosis of some subtypes of meningiomas. (orig.)

  13. Per-beam, planar IMRT QA passing rates do not predict clinically relevant patient dose errors

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E.; Zhen Heming; Tome, Wolfgang A. [Canis Lupus LLC and Department of Human Oncology, University of Wisconsin, Merrimac, Wisconsin 53561 (United States); Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States); Departments of Human Oncology, Medical Physics, and Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53792 (United States)

    2011-02-15

    Purpose: The purpose of this work is to determine the statistical correlation between per-beam, planar IMRT QA passing rates and several clinically relevant, anatomy-based dose errors for per-patient IMRT QA. The intent is to assess the predictive power of a common conventional IMRT QA performance metric, the Gamma passing rate per beam. Methods: Ninety-six unique data sets were created by inducing four types of dose errors in 24 clinical head and neck IMRT plans, each planned with 6 MV Varian 120-leaf MLC linear accelerators using a commercial treatment planning system and step-and-shoot delivery. The error-free beams/plans were used as ''simulated measurements'' (for generating the IMRT QA dose planes and the anatomy dose metrics) to compare to the corresponding data calculated by the error-induced plans. The degree of the induced errors was tuned to mimic IMRT QA passing rates that are commonly achieved using conventional methods. Results: Analysis of clinical metrics (parotid mean doses, spinal cord max and D1cc, CTV D95, and larynx mean) vs IMRT QA Gamma analysis (3%/3 mm, 2/2, 1/1) showed that in all cases, there were only weak to moderate correlations (range of Pearson's r-values: -0.295 to 0.653). Moreover, the moderate correlations actually had positive Pearson's r-values (i.e., clinically relevant metric differences increased with increasing IMRT QA passing rate), indicating that some of the largest anatomy-based dose differences occurred in the cases of high IMRT QA passing rates, which may be called ''false negatives.'' The results also show numerous instances of false positives or cases where low IMRT QA passing rates do not imply large errors in anatomy dose metrics. In none of the cases was there correlation consistent with high predictive power of planar IMRT passing rates, i.e., in none of the cases did high IMRT QA Gamma passing rates predict low errors in anatomy dose metrics or vice versa

  14. Per-beam, planar IMRT QA passing rates do not predict clinically relevant patient dose errors

    International Nuclear Information System (INIS)

    Nelms, Benjamin E.; Zhen Heming; Tome, Wolfgang A.

    2011-01-01

    Purpose: The purpose of this work is to determine the statistical correlation between per-beam, planar IMRT QA passing rates and several clinically relevant, anatomy-based dose errors for per-patient IMRT QA. The intent is to assess the predictive power of a common conventional IMRT QA performance metric, the Gamma passing rate per beam. Methods: Ninety-six unique data sets were created by inducing four types of dose errors in 24 clinical head and neck IMRT plans, each planned with 6 MV Varian 120-leaf MLC linear accelerators using a commercial treatment planning system and step-and-shoot delivery. The error-free beams/plans were used as ''simulated measurements'' (for generating the IMRT QA dose planes and the anatomy dose metrics) to compare to the corresponding data calculated by the error-induced plans. The degree of the induced errors was tuned to mimic IMRT QA passing rates that are commonly achieved using conventional methods. Results: Analysis of clinical metrics (parotid mean doses, spinal cord max and D1cc, CTV D95, and larynx mean) vs IMRT QA Gamma analysis (3%/3 mm, 2/2, 1/1) showed that in all cases, there were only weak to moderate correlations (range of Pearson's r-values: -0.295 to 0.653). Moreover, the moderate correlations actually had positive Pearson's r-values (i.e., clinically relevant metric differences increased with increasing IMRT QA passing rate), indicating that some of the largest anatomy-based dose differences occurred in the cases of high IMRT QA passing rates, which may be called ''false negatives.'' The results also show numerous instances of false positives or cases where low IMRT QA passing rates do not imply large errors in anatomy dose metrics. In none of the cases was there correlation consistent with high predictive power of planar IMRT passing rates, i.e., in none of the cases did high IMRT QA Gamma passing rates predict low errors in anatomy dose metrics or vice versa. Conclusions: There is a lack of correlation between

  15. Degeneracy, frequency response and filtering in IMRT optimization

    International Nuclear Information System (INIS)

    Llacer, Jorge; Agazaryan, Nzhde; Solberg, Timothy D; Promberger, Claus

    2004-01-01

    This paper attempts to provide an answer to some questions that remain either poorly understood, or not well documented in the literature, on basic issues related to intensity modulated radiation therapy (IMRT). The questions examined are: the relationship between degeneracy and frequency response of optimizations, effects of initial beamlet fluence assignment and stopping point, what does filtering of an optimized beamlet map actually do and how could image analysis help to obtain better optimizations? Two target functions are studied, a quadratic cost function and the log likelihood function of the dynamically penalized likelihood (DPL) algorithm. The algorithms used are the conjugate gradient, the stochastic adaptive simulated annealing and the DPL. One simple phantom is used to show the development of the analysis tools used and two clinical cases of medium and large dose matrix size (a meningioma and a prostate) are studied in detail. The conclusions reached are that the high number of iterations that is needed to avoid degeneracy is not warranted in clinical practice, as the quality of the optimizations, as judged by the DVHs and dose distributions obtained, does not improve significantly after a certain point. It is also shown that the optimum initial beamlet fluence assignment for analytical iterative algorithms is a uniform distribution, but such an assignment does not help a stochastic method of optimization. Stopping points for the studied algorithms are discussed and the deterioration of DVH characteristics with filtering is shown to be partially recoverable by the use of space-variant filtering techniques

  16. Degeneracy, frequency response and filtering in IMRT optimization

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, Jorge [EC Engineering Consultants LLC, 130 Forest Hill Drive, Los Gatos, CA 95032 (United States); Agazaryan, Nzhde [Department of Radiation Oncology, University of California, Los Angeles, CA 90095 (United States); Solberg, Timothy D [Department of Radiation Oncology, University of California, Los Angeles, CA 90095 (United States); Promberger, Claus [BrainLAB AG, Ammerthalstrasse 8, 85551 Heimstetten (Germany)

    2004-07-07

    This paper attempts to provide an answer to some questions that remain either poorly understood, or not well documented in the literature, on basic issues related to intensity modulated radiation therapy (IMRT). The questions examined are: the relationship between degeneracy and frequency response of optimizations, effects of initial beamlet fluence assignment and stopping point, what does filtering of an optimized beamlet map actually do and how could image analysis help to obtain better optimizations? Two target functions are studied, a quadratic cost function and the log likelihood function of the dynamically penalized likelihood (DPL) algorithm. The algorithms used are the conjugate gradient, the stochastic adaptive simulated annealing and the DPL. One simple phantom is used to show the development of the analysis tools used and two clinical cases of medium and large dose matrix size (a meningioma and a prostate) are studied in detail. The conclusions reached are that the high number of iterations that is needed to avoid degeneracy is not warranted in clinical practice, as the quality of the optimizations, as judged by the DVHs and dose distributions obtained, does not improve significantly after a certain point. It is also shown that the optimum initial beamlet fluence assignment for analytical iterative algorithms is a uniform distribution, but such an assignment does not help a stochastic method of optimization. Stopping points for the studied algorithms are discussed and the deterioration of DVH characteristics with filtering is shown to be partially recoverable by the use of space-variant filtering techniques.

  17. A case of radiation-induced skin ulcer, cerebral meningioma and skin cancer

    International Nuclear Information System (INIS)

    Matsuo, Yuki; Yano, Kenji

    2000-01-01

    We report a case of radiation-induced skin ulcer, cerebral meningioma, and skin cancer in a 69-year-old woman who had undergone local irradiation and application of radium directly to the skin for actinomycosis of the face at the age of twenty. Some forty to fifty years later, a skin ulcer in the preauricular area in the center of the radiodermatitis, cerebral meningioma in the right sphenoid ridge, and a keratotic skin tumor in the right auricle all developed within the previously irradiated region. The cerebral meningioma was extirpated. The skin ulcer was excised and covered with a forearm flap. After the skin tumor was excised and the subcutaneous tumor in the postauricular area was excised, the postoperative histopathological diagnosis was squamous cell carcinoma with lymph node metastasis. It was considered that the squamous cell carcinoma was derived from irradiated keratosis. Four months later, right neck lymph node dissection was performed. Both the meningioma and squamous cell carcinoma satisfied Cahan's criteria for radiation-induced tumors. So we diagnosed these as radiation-induced cerebral meningioma and squamous cell carcinoma. We haven't detected any recurrence of the squamous cell carcinoma for two years. We learned from this case that chronic radiation disturbances cause an irreversible reaction and various radiolesions, including malignancies, can occur after a long period of latency. It is important to never underestimate a small lesion in the irradiated area, to plan early preventive surgical treatment to remove skin that may have been over-subjected to irradiation, and to continue long-term follow-up for patients with chronic radiodermatitis. (author)

  18. A case of radiation-induced skin ulcer, cerebral meningioma and skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Yuki; Yano, Kenji [Kure National Hospital, Hiroshima (Japan)

    2000-10-01

    We report a case of radiation-induced skin ulcer, cerebral meningioma, and skin cancer in a 69-year-old woman who had undergone local irradiation and application of radium directly to the skin for actinomycosis of the face at the age of twenty. Some forty to fifty years later, a skin ulcer in the preauricular area in the center of the radiodermatitis, cerebral meningioma in the right sphenoid ridge, and a keratotic skin tumor in the right auricle all developed within the previously irradiated region. The cerebral meningioma was extirpated. The skin ulcer was excised and covered with a forearm flap. After the skin tumor was excised and the subcutaneous tumor in the postauricular area was excised, the postoperative histopathological diagnosis was squamous cell carcinoma with lymph node metastasis. It was considered that the squamous cell carcinoma was derived from irradiated keratosis. Four months later, right neck lymph node dissection was performed. Both the meningioma and squamous cell carcinoma satisfied Cahan's criteria for radiation-induced tumors. So we diagnosed these as radiation-induced cerebral meningioma and squamous cell carcinoma. We haven't detected any recurrence of the squamous cell carcinoma for two years. We learned from this case that chronic radiation disturbances cause an irreversible reaction and various radiolesions, including malignancies, can occur after a long period of latency. It is important to never underestimate a small lesion in the irradiated area, to plan early preventive surgical treatment to remove skin that may have been over-subjected to irradiation, and to continue long-term follow-up for patients with chronic radiodermatitis. (author)

  19. The Role of Postoperative Radiotherapy in the Management of Intracranial Meningiomas

    International Nuclear Information System (INIS)

    Chang, Sei Kyung; Suh, Chang Ok; Shin, Hyun Soo; Kim, Gwi Eon

    1994-01-01

    Purpose: To evaluate the role of postoperative radiotherapy in the management of primary or recurrent intracranial meningiomas. Methods and Materials: A retrospective review of 34 intracranial meningioma patients referred to the Yonsei Cancer Center for postoperative radiotherapy between 1981 and 1990 was undertaken. Of the 34 patients, 24 patients received elective postoperative radiotherapy after total or subtotal resection(Group 1), and 10 patients received postoperative radiotherapy as a salvage treatment for recurrent tumors(Group 2). Ten patients received postoperative radiotherapy after total resection, and twenty-four after subtotal resection. Ten patients who had total tumor resection were referred for radiotherapy either because of angioblastic or malignant histologic type (4 patients in Group 1) or because of recurrent disease after initial surgery(6 patients in Group 2). Radiation dose of 50-56Gy was delivered over a period of 5-5.5 weeks using 4MV LINAC or Co-60 teletherapy unit. Results: Overall actuarial progression free survival (PFS) at 5 years was 80%. Survival was most likely affected by histologic subtypes. Five year PFS rate was 52% for benign angioblastic histology, as compared with 100% for classic benign histology. For malignant meningiomas, 5 year PFS rate was 44%. The recurrence rates of classic, angioblastic, and malignant type were 5%(1/21), 80%(4/5), and 50%(4/8), respectively. The duration between salvage post-operative radiotherapy and recurrence was longer than the duration between initial surgery and recurrence in the patients of group 2 with angioblastic or malignant histology. Conclusion: Postoperative radiotherapy of primary or recurrent intracranial meningiomas appears to be effective modality, especially in the patients with classic meningiomas. In angioblastic or malignant histologies, a more effective approach seems to be needed for decreasing recurrence rate

  20. Restricted Field IMRT Dramatically Enhances IMRT Planning for Mesothelioma

    International Nuclear Information System (INIS)

    Allen, Aaron M.; Schofield, Deborah; Hacker, Fred; Court, Laurence E.; Czerminska, Maria M.S.

    2007-01-01

    Purpose: To improve the target coverage and normal tissue sparing of intensity-modulated radiotherapy (IMRT) for mesothelioma after extrapleural pneumonectomy. Methods and Materials: Thirteen plans from patients previously treated with IMRT for mesothelioma were replanned using a restricted field technique. This technique was novel in two ways. It limited the entrance beams to 200 o around the target and three to four beams per case had their field apertures restricted down to the level of the heart or liver to further limit the contralateral lung dose. New constraints were added that included a mean lung dose of <9.5 Gy and volume receiving ≥5 Gy of <55%. Results: In all cases, the planning target volume coverage was excellent, with an average of 97% coverage of the planning target volume by the target dose. No change was seen in the target coverage with the new technique. The heart, kidneys, and esophagus were all kept under tolerance in all cases. The average mean lung dose, volume receiving ≥20 Gy, and volume receiving ≥5 Gy with the new technique was 6.6 Gy, 3.0%, and 50.8%, respectively, compared with 13.8 Gy, 15%, and 90% with the previous technique (p < 0.0001 for all three comparisons). The maximal value for any case in the cohort was 8.0 Gy, 7.3%, and 57.5% for the mean lung dose, volume receiving ≥20 Gy, and volume receiving ≥5 Gy, respectively. Conclusion: Restricted field IMRT provides an improved method to deliver IMRT to a complex target after extrapleural pneumonectomy. An upcoming Phase I trial will provide validation of these results

  1. Current status of intensity-modulated radiation therapy (IMRT)

    International Nuclear Information System (INIS)

    Hatano, Kazuo; Araki, Hitoshi; Sakai, Mitsuhiro

    2007-01-01

    External-beam radiation therapy has been one of the treatment options for prostate cancer. The dose response has been observed for a dose range of 64.8-81 Gy. The problem of external-beam radiotherapy (RT) for prostate cancer is that as the dose increases, adverse effects also increase. Three-dimensional conformal radiation therapy (3D-CRT) has enabled us to treat patients with up to 72-76 Gy to the prostate, with a relatively acceptable risk of late rectal bleeding. Recently, intensity-modulated radiation therapy (IMRT) has been shown to deliver a higher dose to the target with acceptable low rates of rectal and bladder complications. The most important things to keep in mind when using an IMRT technique are that there is a significant trade-off between coverage of the target, avoidance of adjacent critical structures, and the inhomogeneity of the dose within the target. Lastly, even with IMRT, it should be kept in mind that a ''perfect'' plan that creates completely homogeneous coverage of the target volume and zero or small dose to the adjacent organs at risk is not always obtained. Participating in many treatment planning sessions and arranging the beams and beam weights create the best approach to the best IMRT plan. (author)

  2. Consequences of leaf calibration errors on IMRT delivery

    International Nuclear Information System (INIS)

    Sastre-Padro, M; Welleweerd, J; Malinen, E; Eilertsen, K; Olsen, D R; Heide, U A van der

    2007-01-01

    IMRT treatments using multi-leaf collimators may involve a large number of segments in order to spare the organs at risk. When a large proportion of these segments are small, leaf positioning errors may become relevant and have therapeutic consequences. The performance of four head and neck IMRT treatments under eight different cases of leaf positioning errors has been studied. Systematic leaf pair offset errors in the range of ±2.0 mm were introduced, thus modifying the segment sizes of the original IMRT plans. Thirty-six films were irradiated with the original and modified segments. The dose difference and the gamma index (with 2%/2 mm criteria) were used for evaluating the discrepancies between the irradiated films. The median dose differences were linearly related to the simulated leaf pair errors. In the worst case, a 2.0 mm error generated a median dose difference of 1.5%. Following the gamma analysis, two out of the 32 modified plans were not acceptable. In conclusion, small systematic leaf bank positioning errors have a measurable impact on the delivered dose and may have consequences for the therapeutic outcome of IMRT

  3. Primary atypical sacral meningioma- not always benign

    International Nuclear Information System (INIS)

    Bhadra, A.K.; Casey, A.T.H.; Saifuddin, A.; Briggs, T.W.

    2007-01-01

    We present a case of an atypical recurrent meningioma of the sacrum with pulmonary metastasis in a 31-year-old man. He presented with deep-seated buttock pain and urinary hesitancy for 3 months. MRI revealed a lesion occupying the central and left side of the sacral canal at the S1-S2 level. Surgical excision of the lesion via a posterior approach was undertaken, and the patient became symptom-free post-operatively. Histology confirmed atypical meningioma. Eight months later he re-presented with similar symptoms, and MRI confirmed local recurrence. The patient underwent left hemisacrectomy. Six months later he again presented with low back pain and MRI confirmed a second local recurrence. A CT scan of the chest showed multiple lung metastases. The patient died of a severe chest infection 18 months later. (orig.)

  4. Brain edema associated with intracranial meningiomas

    International Nuclear Information System (INIS)

    Asahi, Minoru; Kikuchi, Haruhiko; Hirai, Osamu

    1992-01-01

    Brain edema associated with intracranial meningiomas was investigated on 80 patients, excluding recurrent cases. Statistically significant positive correlations with the degree of edema were found with large tumors, the convexity or parasagittal locations, the venous outflow disturbance, and the evidence of cortical disruption or peritumoral enhancement visualized on computed tomography or magnetic resonance imagings. Patients with a short clinical history and with angiographic evidence of hypervascularity tended to have edema, but there was no statistical significance. It is concluded that various factors are responsible for the edema associated with meningiomas and that it would be hard to determine the most important cause, since each factor plays a part edema production, spread, and resolution. (author)

  5. Olfactory groove meningiomas: approaches and complications.

    Science.gov (United States)

    Aguiar, Paulo Henrique Pires de; Tahara, Adriana; Almeida, Antonio Nogueira; Simm, Renata; Silva, Arnaldo Neves da; Maldaun, Marcos Vinicius Calfatt; Panagopoulos, Alexandros Theodoros; Zicarelli, Carlos Alexandre; Silva, Pedro Gabriel

    2009-09-01

    Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

  6. Primary atypical sacral meningioma- not always benign

    Energy Technology Data Exchange (ETDEWEB)

    Bhadra, A.K.; Casey, A.T.H.; Saifuddin, A.; Briggs, T.W. [Royal National Orthopaedic Hospital, Stanmore, London (United Kingdom)

    2007-06-15

    We present a case of an atypical recurrent meningioma of the sacrum with pulmonary metastasis in a 31-year-old man. He presented with deep-seated buttock pain and urinary hesitancy for 3 months. MRI revealed a lesion occupying the central and left side of the sacral canal at the S1-S2 level. Surgical excision of the lesion via a posterior approach was undertaken, and the patient became symptom-free post-operatively. Histology confirmed atypical meningioma. Eight months later he re-presented with similar symptoms, and MRI confirmed local recurrence. The patient underwent left hemisacrectomy. Six months later he again presented with low back pain and MRI confirmed a second local recurrence. A CT scan of the chest showed multiple lung metastases. The patient died of a severe chest infection 18 months later. (orig.)

  7. Prostate carcinoma mimicking a sphenoid wing meningioma.

    Science.gov (United States)

    Bradley, Lucas H; Burton, Matthew; Gokden, Murat; Serletis, Demitre

    2015-01-01

    We report here on a rare case of a large, lateral sphenoid wing tumor with radiographic and intraoperative findings highly suggestive of meningioma, yet pathology was in fact consistent with metastatic prostate adenocarcinoma. An 81 year-old male presented with expressive dysphasia, right-sided weakness and headaches. Imaging revealed a heterogeneously-enhancing lesion based on the left lateral sphenoid wing. The presumed diagnosis was strongly in favor of meningioma, and the patient underwent complete resection of the dural-based lesion. Final pathology confirmed the unexpected finding of a metastatic prostate adenocarcinoma. Although he tolerated surgery well, the patient was subsequently referred for palliative therapy given findings of widespread systemic disease. Intracranial metastases may involve the dura, at times presenting with rare radiographic features highly suggestive for meningioma, as in our case here. This makes differentiation, at least based on imaging, a challenge. Elderly patients presenting with neurological deficits secondary to a newly-diagnosed, dural-based lesion should thus be considered for metastasis, prompting additional imaging studies (including body CT, MRI or PET) to rule out a primary lesion elsewhere. In some cases, this may affect the overall decision to proceed with surgical resection, or alternatively, to proceed directly to palliative therapy (the latter decision made in the context of widespread metastatic disease). We conclude that dural-based metastatic lesions may mimic meningiomas, warranting thorough pre-operative work-up to exclude the possibility of metastasis. In certain cases, identification of widespread disease might preclude surgery and favor palliation, instead. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. A planning and delivery study of a rotational IMRT technique with burst delivery

    International Nuclear Information System (INIS)

    Kainz, Kristofer; Chen, Guang-Pei; Chang, Yu-Wen; Prah, Douglas; Sharon Qi, X.; Shukla, Himanshu P.; Stahl, Johannes; Allen Li, X.

    2011-01-01

    Purpose: A novel rotational IMRT (rIMRT) technique using burst delivery (continuous gantry rotation with beam off during MLC repositioning) is investigated. The authors evaluate the plan quality and delivery efficiency and accuracy of this dynamic technique with a conventional flat 6 MV photon beam. Methods: Burst-delivery rIMRT was implemented in a planning system and delivered with a 160-MLC linac. Ten rIMRT plans were generated for five anonymized patient cases encompassing head and neck, brain, prostate, and prone breast. All plans were analyzed retrospectively and not used for treatment. Among the varied plan parameters were the number of optimization points, number of arcs, gantry speed, and gantry angle range (alpha) over which the beam is turned on at each optimization point. Combined rotational/step-and-shoot rIMRT plans were also created by superimposing multiple-segment static fields at several optimization points. The rIMRT trial plans were compared with each other and with plans generated using helical tomotherapy and VMAT. Burst-mode rotational IMRT plans were delivered and verified using a diode array, ionization chambers, thermoluminescent dosimeters, and film. Results: Burst-mode rIMRT can achieve plan quality comparable to helical tomotherapy, while the former may lead to slightly better OAR sparing for certain cases and the latter generally achieves slightly lower hot spots. Few instances were found in which increasing the number of optimization points above 36, or superimposing step-and-shoot IMRT segments, led to statistically significant improvements in OAR sparing. Using an additional rIMRT partial arc yielded substantial OAR dose improvements for the brain case. Measured doses from the rIMRT plan delivery were within 4% of the plan calculation in low dose gradient regions. Delivery time range was 228-375 s for single-arc rIMRT 200-cGy prescription with a 300 MU/min dose rate, comparable to tomotherapy and VMAT. Conclusions: Rotational IMRT

  9. Imaging diagnosis of meningiomas of ethmoid sinuses

    International Nuclear Information System (INIS)

    Lu Bingfeng; Liang Shuming; Li Mao

    2001-01-01

    Objective: To study the imaging features of meningiomas of ethmoid sinuses. Methods: Six cases of meningiomas of ethmoid sinuses verified pathologically were analyzed retrospectively. Results: CT scans of 6 cases exhibited huge cystic masses (n = 3), huge cystic-solid masses (n = 2), huge solid mass (n = 1). The cystic walls were remarkable osteosclerosis. The density of solid masses were homogeneous, or heterogeneous with calcifications and cystic changes, and prominent contrast-enhancement. MR images of 1 case (1/6) showed a cystic-solid mass, the cystic portion was high signal intensity on T 2 WI and low signal intensity on T 1 WI, while the solid mass was iso-signal intensity on T 1 WI and T 2 WI. The solid portion was enhanced. X-ray plain films of 3 cases (3/6) displayed ethmoid sinuses enlargement and high density. Conclusion: For the meningiomas of ethmoid sinuses, CT finding was specific, MRI was helpful in differential diagnosis, and X-ray plain films was of no qualitative value

  10. Limited parameter set IMRT for carcinoma breast

    International Nuclear Information System (INIS)

    Gopinath, M.; Sharma, Sanjiv; Vivek, T.R.; Suparna; Deka, Preeti; Manikandan; Giriraj

    2008-01-01

    Post operative radiotherapy after breast conservation surgery is an effective and widely accepted treatment modality in early stage breast cancer. The treatment is usually performed using two wedged tangential photon beams. The disadvantage of this technique is significant dose inhomogeneity as large as 15-20% in the superior and inferior regions of the breast due to lesser transmission thickness and in the medial and lateral aspect of the breast due to lower attenuation of lung tissue in the field. The aim of the study is to modify the conventional wedged tangential pair to achieve a more homogeneous dose distribution and a reduction in acute toxicity and improved cosmetic result. A comparative study is done between the conventional wedged technique and limited parameter set IMRT

  11. Theoretical and practical model for implementing intensity modulated radiotherapy (IMRT) based on openness in head and neck tumors

    International Nuclear Information System (INIS)

    Napoles Morales, Misleidy; Yanes Lopez, Yaima; Ascension, Yudith; Alfonso La Guardia, Rodolfo; Calderon, Carlos

    2009-01-01

    Certain requirements have been internationally recommended for the transition from radiation therapy (3D-CRT) to intensity modulated radiation therapy (IMRT). They have been filling in clinical practice in the physical, dosimetry and quality of treatment. Prior to the implementation of IMRT have been developed preclinical will proceed according to the treatment planning techniques in the real images of patients, validating the rationale for the transition from the point of view and radiobiological dosimetry. The comparison was based on a group of patients eligible for IMRT, which were actually treated with 3D-CRT. IMRT plans were designed and applied to virtually the same patients, simulating the IMRT treatment. The prescribed dose and fractionation were similar in both techniques, to be able to compare radiobiology. The results show the rationality of IMRT in terms of reducing complications and the possibility of scaling doses in the PTV. Were used Dose Volume Histograms (HDV) obtained from the dosimetric calculations for radiobiological evaluation of treatment plans, letting through a software: 'Albireo Target' version 4.0.1.2008 calculate the equivalent uniform dose (EUD) for tumor and organs of risks (OAR) and tumor control probability (TCP) and the likelihood of damage to healthy tissue (NTCP). The results obtained with IMRT plans were more significant than with 3D-CRT especially in terms of EUD for organs at risk and NTCP. These results allow us to create the definitive basis for the implementation of IMRT in our environment. (Author)

  12. Hormone replacement therapy increases the risk of cranial meningioma

    DEFF Research Database (Denmark)

    Andersen, Lene; Friis, Søren; Hallas, Jesper

    2013-01-01

    We investigated the influence of hormone replacement therapy (HRT) use on the risk of meningioma in a population-based setting.......We investigated the influence of hormone replacement therapy (HRT) use on the risk of meningioma in a population-based setting....

  13. Suprasellar Anaplastic Meningioma Masquerading As Craniopharyngioma: A Case Report

    Directory of Open Access Journals (Sweden)

    Eman Abdelzaher

    2014-06-01

    Full Text Available Anaplastic meningiomas are uncommon. We report the clinical, radiological and pathological features of an anaplastic meningioma in a young male Egyptian patient presenting as a suprasellar solid/cystic enhancing mass resembling a craniopharyngioma. [J Interdiscipl Histopathol 2014; 2(3.000: 154-157

  14. Lipomatous secretory meningioma: case report and review of the literature

    International Nuclear Information System (INIS)

    Liebig, T.; Hoffmann, T.; Hosten, N.; Sander, B.; Lanksch, W.R.

    1998-01-01

    Secretory meningioma is a rare entity which may be characterised by imaging features unusual for other subtypes of meningoma, such as low attenuation on CT, high (fat-tissue equivalent) signal intensity on T1-weighted MRI, marked surrounding oedema, and irregular contrast enhancement. We report a case of secretory meningioma and review the literature. (orig.) (orig.)

  15. Perfusion MR imaging for differentiation of benign and malignant meningiomas

    NARCIS (Netherlands)

    Zhang, Hao; Rodiger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    Introduction Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. Methods A total of 33 patients with preoperative meningiomas (25 benign and

  16. Rare suprasellar chordoid meningioma with INI1 gene mutation ...

    African Journals Online (AJOL)

    Background: Chordoid Meningioma is a rare brain tumour characterized genetically by loss of genetic material from chromosome 22q at cytogenetic level resulting in mutation of NF2 gene. Objectives and case report: In the present report, we described a rare case of suprasellar chordoid meningioma, which presented in a ...

  17. Evaluation tools of quality control for patients submitted to IMRT

    International Nuclear Information System (INIS)

    Lavor, Milton

    2011-01-01

    Intensity modulated radiation therapy (IMRT) is currently been implemented in a rapidly growing number of centers in Brazil. As consequence many institutions are now facing the problem of performing a comprehensive quality control program before and during the implementation of IMRT in the clinical routine practice. The aim of this work is to evaluate and propose a methodology for quality assurance in IMRT treatments. An ionization chamber and a two-dimensional array detector were performed to assess the absolute value of the total dose of all fields in one specific point. The relative total dose distribution of all fields was measured with a radiochromic film and a two-dimensional array at one depth in a phantom. A comparison between measured and calculated dose distributions was performed using the gamma-index method, assessing the percentage of points that meet the criteria of +-3% dose difference and +-3 mm distance to agreement. As a result of 113 tested IMRT beams using ionization chamber and 81 using two-dimensional array, the proposal was to take an action level of about +- 5% compared to the treatment planning systems and measurements, for the verification of the dose in a single point at the low gradient dose region. Analysis of the two-dimensional array measurements showed that the gamma value was <1 for 97.7% of the data and for the film the gamma value was <1 for 96.6% of the data. This can be concluded that for an accurate delivery of dose in 'sliding-window' IMRT with micro multileaf collimator, the absolute value of the total dose and the relative total dose distribution should be checked by absolute and relative dosimetry respectively. (author)

  18. Dural attachment of intracranial meningiomas: evaluation with contrast-enhanced three-dimensional fast imaging with steady-state acquisition (FIESTA) at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Junkoh; Takahashi, Mayu; Aoyama, Yuichi; Soejima, Yoshiteru; Saito, Takeshi; Akiba, Daisuke; Nishizawa, Shigeru [University of Occupational and Environmental Health, Department of Neurosurgery, Kitakyusyu (Japan); Kakeda, Shingo; Korogi, Yukunori [University of Occupational and Environmental Health, Department of Radiology, Kitakyusyu (Japan)

    2011-06-15

    The purpose of this study was to evaluate the role of contrast-enhanced fast imaging with steady-state acquisition (CE-FIESTA) for assessing whether dural attachment in intracranial meningiomas is adhesive or not by correlation with intraoperative findings. Fourteen consecutive patients who were candidates for surgical treatment of meningiomas were prospectively analyzed with preoperative magnetic resonance imaging, including CE-FIESTA at 3 T. First, two neuroradiologists assessed several characteristics of the attachment of the meningioma to the dura mater or skull base on CE-FIESTA images. Second, the surgical findings of adhesion at the dural attachment of meningiomas were evaluated by two neurosurgeons. Finally, the CE-FIESTA findings were correlated with the surgical findings by one neurosurgeon and one neuroradiologist by consensus. CE-FIESTA clearly depicted a hypointense marginal line at the attachment site of the meningioma. When CE-FIESTA revealed smooth marginal lines or hyperintense zones along the marginal lines, tumors were detached easily from the dura mater. On the contrary, when CE-FIESTA showed an irregularity, such as partial disruption of the marginal lines, vessels, or bony hyperostosis, the tumors tended to adhere firmly to the dura mater, which was found to contain small vessels and fine fibrous tissues. There seems to be an excellent correlation between the characteristics of dural attachment of meningiomas on CE-FIESTA images and intraoperative findings. Therefore, for operative planning, CE-FIESTA may provide useful information regarding the adhesiveness of dural attachment. (orig.)

  19. Dural attachment of intracranial meningiomas: evaluation with contrast-enhanced three-dimensional fast imaging with steady-state acquisition (FIESTA) at 3 T

    International Nuclear Information System (INIS)

    Yamamoto, Junkoh; Takahashi, Mayu; Aoyama, Yuichi; Soejima, Yoshiteru; Saito, Takeshi; Akiba, Daisuke; Nishizawa, Shigeru; Kakeda, Shingo; Korogi, Yukunori

    2011-01-01

    The purpose of this study was to evaluate the role of contrast-enhanced fast imaging with steady-state acquisition (CE-FIESTA) for assessing whether dural attachment in intracranial meningiomas is adhesive or not by correlation with intraoperative findings. Fourteen consecutive patients who were candidates for surgical treatment of meningiomas were prospectively analyzed with preoperative magnetic resonance imaging, including CE-FIESTA at 3 T. First, two neuroradiologists assessed several characteristics of the attachment of the meningioma to the dura mater or skull base on CE-FIESTA images. Second, the surgical findings of adhesion at the dural attachment of meningiomas were evaluated by two neurosurgeons. Finally, the CE-FIESTA findings were correlated with the surgical findings by one neurosurgeon and one neuroradiologist by consensus. CE-FIESTA clearly depicted a hypointense marginal line at the attachment site of the meningioma. When CE-FIESTA revealed smooth marginal lines or hyperintense zones along the marginal lines, tumors were detached easily from the dura mater. On the contrary, when CE-FIESTA showed an irregularity, such as partial disruption of the marginal lines, vessels, or bony hyperostosis, the tumors tended to adhere firmly to the dura mater, which was found to contain small vessels and fine fibrous tissues. There seems to be an excellent correlation between the characteristics of dural attachment of meningiomas on CE-FIESTA images and intraoperative findings. Therefore, for operative planning, CE-FIESTA may provide useful information regarding the adhesiveness of dural attachment. (orig.)

  20. Comparative dosimetric analysis of IMRT and VMAT (RapidArc in brain, head and neck, breast and prostate malignancies

    Directory of Open Access Journals (Sweden)

    Mirza Athar Ali

    2015-03-01

    Full Text Available Purpose: Intensity modulated radiotherapy (IMRT in the recent past has established itself as a gold standard for organs at risk (OAR sparing, target coverage and dose conformity. With the advent of a rotational treatment technology such as volumetric modulated arc therapy (VMAT, an inter-comparison is warranted to address the advantages and disadvantages of each technique. Methods: Twenty patients were selected retrospectively from our patient database. Sites included were brain, head and neck, chest wall, and prostate, with five patients for each site. For all the selected patients, both the IMRT and VMAT treatment plans were generated. Plan comparison was done in terms of OAR dose, dose homogeneity index (HI, dose conformity index (CI, target coverage, low isodose volumes, monitor units (MUs, and treatment time.Results: The VMAT showed better sparing of “parotids minus planning target volume (PTV”, spinal cord and head of femur as compared to the IMRT. The lung V40 for VMAT was lower, whereas the lung V10, contralateral lung mean dose, contralateral breast mean dose and mean body dose were lower with IMRT for chest wall cases. Both the VMAT and IMRT achieved comparable HI except for the brain site, where IMRT scored over VMAT. The CI achieved by the IMRT and VMAT were similar except for chest wall cases, whereas the VMAT achieved better dose conformity. The target coverage was comparable with both the plans. The VMAT clearly scored over IMRT in terms of average MUs (486 versus 812 respectively and average treatment time (2.54 minutes versus 5.54 minutes per treatment session. Conclusion: The VMAT (RapidArc has a potential to generate treatment plans for various anatomical sites which are comparable with the corresponding IMRT plans in terms of OAR sparing and plan quality parameters. The VMAT significantly reduces treatment time as compared to the IMRT, thus VMAT can increase the throughput of a busy radiotherapy department.

  1. Comparison of VMAT and IMRT strategies for cervical cancer patients using automated planning.

    Science.gov (United States)

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

    2015-03-01

    In a published study on cervical cancer, 5-beam IMRT was inferior to single arc VMAT. Here we compare 9, 12, and 20 beam IMRT with single and dual arc VMAT. For each of 10 patients, automated plan generation with the in-house Erasmus-iCycle optimizer was used to assist an expert planner in generating the five plans with the clinical TPS. For each patient, all plans were clinically acceptable with a high and similar PTV coverage. OAR sparing increased when going from 9 to 12 to 20 IMRT beams, and from single to dual arc VMAT. For all patients, 12 and 20 beam IMRT were superior to single and dual arc VMAT, with substantial variations in gain among the study patients. As expected, delivery of VMAT plans was significantly faster than delivery of IMRT plans. Often reported increased plan quality for VMAT compared to IMRT has not been observed for cervical cancer. Twenty and 12 beam IMRT plans had a higher quality than single and dual arc VMAT. For individual patients, the optimal delivery technique depends on a complex trade-off between plan quality and treatment time that may change with introduction of faster delivery systems. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Comparison of VMAT and IMRT strategies for cervical cancer patients using automated planning

    International Nuclear Information System (INIS)

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

    2015-01-01

    Background and purpose: In a published study on cervical cancer, 5-beam IMRT was inferior to single arc VMAT. Here we compare 9, 12, and 20 beam IMRT with single and dual arc VMAT. Material and methods: For each of 10 patients, automated plan generation with the in-house Erasmus-iCycle optimizer was used to assist an expert planner in generating the five plans with the clinical TPS. Results: For each patient, all plans were clinically acceptable with a high and similar PTV coverage. OAR sparing increased when going from 9 to 12 to 20 IMRT beams, and from single to dual arc VMAT. For all patients, 12 and 20 beam IMRT were superior to single and dual arc VMAT, with substantial variations in gain among the study patients. As expected, delivery of VMAT plans was significantly faster than delivery of IMRT plans. Conclusions: Often reported increased plan quality for VMAT compared to IMRT has not been observed for cervical cancer. Twenty and 12 beam IMRT plans had a higher quality than single and dual arc VMAT. For individual patients, the optimal delivery technique depends on a complex trade-off between plan quality and treatment time that may change with introduction of faster delivery systems

  3. Steroid hormone and epidermal growth factor receptors in meningiomas.

    Science.gov (United States)

    Horsfall, D J; Goldsmith, K G; Ricciardelli, C; Skinner, J M; Tilley, W D; Marshall, V R

    1989-11-01

    A prospective study of steroid hormone and epidermal growth factor receptor expression in 57 meningiomas is presented. Scatchard analysis of radioligand binding identified 20% of meningiomas as expressing classical oestrogen receptors (ER) at levels below that normally accepted for positivity, the remainder being negative. ER could not be visualized in any meningioma using immunocytochemistry. Alternatively, 74% of meningiomas demonstrated the presence of progesterone receptors (PR) by Scatchard analysis, the specificity of which could not be attributed to glucocorticoid or androgen receptors. Confirmation of classical PR presence was determined by immunocytochemical staining. The presence of epidermal growth factor receptor (EGFR) was demonstrated in 100% of meningiomas using immunocytochemical staining. These data are reviewed in the context of previously reported results and are discussed in relation to the potential for medical therapy as an adjunct to surgery.

  4. Dosimetric adaptive IMRT driven by fiducial points

    International Nuclear Information System (INIS)

    Crijns, Wouter; Van Herck, Hans; Defraene, Gilles; Van den Bergh, Laura; Haustermans, Karin; Slagmolen, Pieter; Maes, Frederik; Van den Heuvel, Frank

    2014-01-01

    Purpose: Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy have become standard treatments but are more sensitive to anatomical variations than 3D conformal techniques. To correct for inter- and intrafraction anatomical variations, fast and easy to implement methods are needed. Here, the authors propose a full dosimetric IMRT correction that finds a compromise in-between basic repositioning (the current clinical practice) and full replanning. It simplifies replanning by avoiding a recontouring step and a full dose calculation. It surpasses repositioning by updating the preoptimized fluence and monitor units (MU) using a limited number of fiducial points and a pretreatment (CB)CT. To adapt the fluence the fiducial points were projected in the beam's eye view (BEV). To adapt the MUs, point dose calculation towards the same fiducial points were performed. The proposed method is intrinsically fast and robust, and simple to understand for operators, because of the use of only four fiducial points and the beam data based point dose calculations. Methods: To perform our dosimetric adaptation, two fluence corrections in the BEV are combined with two MU correction steps along the beam's path. (1) A transformation of the fluence map such that it is realigned with the current target geometry. (2) A correction for an unintended scaling of the penumbra margin when the treatment beams scale to the current target size. (3) A correction for the target depth relative to the body contour and (4) a correction for the target distance to the source. The impact of the correction strategy and its individual components was evaluated by simulations on a virtual prostate phantom. This heterogeneous reference phantom was systematically subjected to population based prostate transformations to simulate interfraction variations. Additionally, a patient example illustrated the clinical practice. The correction strategy was evaluated using both dosimetric

  5. Dosimetric adaptive IMRT driven by fiducial points

    Energy Technology Data Exchange (ETDEWEB)

    Crijns, Wouter, E-mail: wouter.crijns@uzleuven.be [Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Herestraat 49, 3000 Leuven, Belgium and Medical Imaging Research Center, KU Leuven, Herestraat 49, 3000 Leuven (Belgium); Van Herck, Hans [Medical Imaging Research Center, KU Leuven, Herestraat 49, 3000 Leuven, Belgium and Department of Electrical Engineering (ESAT) – PSI, Center for the Processing of Speech and Images, KU Leuven, 3000 Leuven (Belgium); Defraene, Gilles; Van den Bergh, Laura; Haustermans, Karin [Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Herestraat 49, 3000 Leuven (Belgium); Slagmolen, Pieter [Medical Imaging Research Center, KU Leuven, Herestraat 49, 3000 Leuven (Belgium); Department of Electrical Engineering (ESAT) – PSI, Center for the Processing of Speech and Images, KU Leuven, 3000 Leuven (Belgium); iMinds-KU Leuven Medical IT Department, KU Leuven, 3000 Leuven (Belgium); Maes, Frederik [Medical Imaging Research Center, KU Leuven, Herestraat 49, 3000 Leuven (Belgium); Department of Electrical Engineering (ESAT) – PSI, Center for the Processing of Speech and Images, KU Leuven and iMinds, 3000 Leuven (Belgium); Van den Heuvel, Frank [Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Herestraat 49, 3000 Leuven, Belgium and Department of Oncology, MRC-CR-UK Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford OX1 2JD (United Kingdom)

    2014-06-15

    Purpose: Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy have become standard treatments but are more sensitive to anatomical variations than 3D conformal techniques. To correct for inter- and intrafraction anatomical variations, fast and easy to implement methods are needed. Here, the authors propose a full dosimetric IMRT correction that finds a compromise in-between basic repositioning (the current clinical practice) and full replanning. It simplifies replanning by avoiding a recontouring step and a full dose calculation. It surpasses repositioning by updating the preoptimized fluence and monitor units (MU) using a limited number of fiducial points and a pretreatment (CB)CT. To adapt the fluence the fiducial points were projected in the beam's eye view (BEV). To adapt the MUs, point dose calculation towards the same fiducial points were performed. The proposed method is intrinsically fast and robust, and simple to understand for operators, because of the use of only four fiducial points and the beam data based point dose calculations. Methods: To perform our dosimetric adaptation, two fluence corrections in the BEV are combined with two MU correction steps along the beam's path. (1) A transformation of the fluence map such that it is realigned with the current target geometry. (2) A correction for an unintended scaling of the penumbra margin when the treatment beams scale to the current target size. (3) A correction for the target depth relative to the body contour and (4) a correction for the target distance to the source. The impact of the correction strategy and its individual components was evaluated by simulations on a virtual prostate phantom. This heterogeneous reference phantom was systematically subjected to population based prostate transformations to simulate interfraction variations. Additionally, a patient example illustrated the clinical practice. The correction strategy was evaluated using both dosimetric

  6. BOLD MRI response to hypercapnic hyperoxia in patients with meningiomas: correlation with Gadolinium-DTPA uptake rate.

    NARCIS (Netherlands)

    Rijpkema, M.J.P.; Schuuring, J.; Bernsen, P.; Bernsen, H.J.J.A.; Kaanders, J.H.A.M.; Kogel, A.J. van der; Heerschap, A.

    2004-01-01

    Because meningiomas tend to recur after (partial) surgical resection, radiotherapy is increasingly being applied for the treatment of these tumors. Radiation dose levels are limited, however, to avoid radiation damage to the surrounding normal tissue. The radiosensitivity of tumors can be improved

  7. Rotational IMRT techniques compared to fixed gantry IMRT and Tomotherapy: multi-institutional planning study for head-and-neck cases

    Directory of Open Access Journals (Sweden)

    Lutters Gerd

    2011-02-01

    Full Text Available Abstract Background Recent developments enable to deliver rotational IMRT with standard C-arm gantry based linear accelerators. This upcoming treatment technique was benchmarked in a multi-center treatment planning study against static gantry IMRT and rotational IMRT based on a ring gantry for a complex parotid gland sparing head-and-neck technique. Methods Treatment plans were created for 10 patients with head-and-neck tumours (oropharynx, hypopharynx, larynx using the following treatment planning systems (TPS for rotational IMRT: Monaco (ELEKTA VMAT solution, Eclipse (Varian RapidArc solution and HiArt for the helical tomotherapy (Tomotherapy. Planning of static gantry IMRT was performed with KonRad, Pinnacle and Panther DAO based on step&shoot IMRT delivery and Eclipse for sliding window IMRT. The prescribed doses for the high dose PTVs were 65.1Gy or 60.9Gy and for the low dose PTVs 55.8Gy or 52.5Gy dependend on resection status. Plan evaluation was based on target coverage, conformity and homogeneity, DVHs of OARs and the volume of normal tissue receiving more than 5Gy (V5Gy. Additionally, the cumulative monitor units (MUs and treatment times of the different technologies were compared. All evaluation parameters were averaged over all 10 patients for each technique and planning modality. Results Depending on IMRT technique and TPS, the mean CI values of all patients ranged from 1.17 to 2.82; and mean HI values varied from 0.05 to 0.10. The mean values of the median doses of the spared parotid were 26.5Gy for RapidArc and 23Gy for VMAT, 14.1Gy for Tomo. For fixed gantry techniques 21Gy was achieved for step&shoot+KonRad, 17.0Gy for step&shoot+Panther DAO, 23.3Gy for step&shoot+Pinnacle and 18.6Gy for sliding window. V5Gy values were lowest for the sliding window IMRT technique (3499 ccm and largest for RapidArc (5480 ccm. The lowest mean MU value of 408 was achieved by Panther DAO, compared to 1140 for sliding window IMRT. Conclusions All

  8. Rotational IMRT techniques compared to fixed gantry IMRT and Tomotherapy: multi-institutional planning study for head-and-neck cases

    International Nuclear Information System (INIS)

    Wiezorek, Tilo; Schubert, Kai; Wagner, Daniela; Wendt, Thomas G; Brachwitz, Tim; Georg, Dietmar; Blank, Eyck; Fotina, Irina; Habl, Gregor; Kretschmer, Matthias; Lutters, Gerd; Salz, Henning

    2011-01-01

    Recent developments enable to deliver rotational IMRT with standard C-arm gantry based linear accelerators. This upcoming treatment technique was benchmarked in a multi-center treatment planning study against static gantry IMRT and rotational IMRT based on a ring gantry for a complex parotid gland sparing head-and-neck technique. Treatment plans were created for 10 patients with head-and-neck tumours (oropharynx, hypopharynx, larynx) using the following treatment planning systems (TPS) for rotational IMRT: Monaco (ELEKTA VMAT solution), Eclipse (Varian RapidArc solution) and HiArt for the helical tomotherapy (Tomotherapy). Planning of static gantry IMRT was performed with KonRad, Pinnacle and Panther DAO based on step&shoot IMRT delivery and Eclipse for sliding window IMRT. The prescribed doses for the high dose PTVs were 65.1Gy or 60.9Gy and for the low dose PTVs 55.8Gy or 52.5Gy dependend on resection status. Plan evaluation was based on target coverage, conformity and homogeneity, DVHs of OARs and the volume of normal tissue receiving more than 5Gy (V 5Gy ). Additionally, the cumulative monitor units (MUs) and treatment times of the different technologies were compared. All evaluation parameters were averaged over all 10 patients for each technique and planning modality. Depending on IMRT technique and TPS, the mean CI values of all patients ranged from 1.17 to 2.82; and mean HI values varied from 0.05 to 0.10. The mean values of the median doses of the spared parotid were 26.5Gy for RapidArc and 23Gy for VMAT, 14.1Gy for Tomo. For fixed gantry techniques 21Gy was achieved for step&shoot+KonRad, 17.0Gy for step&shoot+Panther DAO, 23.3Gy for step&shoot+Pinnacle and 18.6Gy for sliding window. V 5Gy values were lowest for the sliding window IMRT technique (3499 ccm) and largest for RapidArc (5480 ccm). The lowest mean MU value of 408 was achieved by Panther DAO, compared to 1140 for sliding window IMRT. All IMRT delivery technologies with their associated TPS

  9. Film dosimetry for IMRT: sensitivity corrections

    International Nuclear Information System (INIS)

    Suchowerska, N.; Hoban, P.; Davison, A.; Metcalfe, P.

    2000-01-01

    Full text: The trend towards conformal, dynamic and intensity modulated radiotherapy treatments has furthered the need for true integrating dosimetry. In traditional radiotherapy, film dosimetry is commonly used. The accuracy and reproducibility of film optical density as an indicator of dose, has been associated with several variables. These include the effects of film specific sensitivity, direction of exposure, chemical processing and film scanner sensitivity. In this study, a procedure is developed to account for these variables, with a particular view to film being used as a dosimeter for conformal treatments. An effective sensitometric curve was established by exposing part of a single sheet of film to known doses. All films were processed together and scanned using a DuoscanT1200 transmission scanner, resulting in 12 bit image files. The images were analysed using Osiris software and the results fitted to the modified Williamson equation: P P s (l - 10 αD ) This yields values of α [film sensitivity], and P s [saturation pixel value], allowing individual dosimetry films to be normalised to this sensitometric calibration curve. For validation, a piece of Kodak X Omat-V film was sealed in a head phantom and exposed to a total of 51 IMRT fields, delivered from 6 gantry angles. The rest of the sheet of film was resealed and exposed to four known doses, providing sensitometric data, specific to this exposure. All films were then processed, scanned and analysed as described above. Observed variations in serial films exposed to 50cGy is in the order of 9% [mean 25.0,standard deviation = 3.2]. The automatic gain of the scanner system typically contributed 4% variation and needs to be carefully monitored. Results indicate that by using the sensitometric data from each exposure, the collective errors can be minimised. The IMRT exposure results confirm that the above process is viable for use in dosimetry for conformal radiation therapy. Copyright (2000) Australasian

  10. Analysis of results of checks IMRT in almost a thousand patients

    International Nuclear Information System (INIS)

    Richart, J.; Doval, S.; Perez-Calatayud, J.; Depieaggio, M.; Rodriguez, S.; Santos, M.

    2013-01-01

    Since November 2006 IMRT treatments being made in the mode of sliding-window in our Hospital. The major sites of application of this technique are: head and neck, prostate, and gynecological. Specific checks are performed of each plan both yield and analysis ionometric extent in which a dummy was exported IMRT plan. Over one thousand patients, the objective of this work is the presentation and analysis of results. (Author)

  11. Matching tomographic IMRT fields with static photon fields

    International Nuclear Information System (INIS)

    Sethi, A.; Leybovich, L.; Dogan, N.; Emami, B.

    2001-01-01

    The matching of abutting radiation fields presents a challenging problem in radiation therapy. Due to sharp penumbra of linear accelerator beams, small (1-2 mm) errors in field positioning can lead to large (>30%) hot or cold spots in the abutment region. With head and neck immobilization devices (thermoplastic mask/aquaplast) an average setup error of 3 mm has been reported. Therefore hot or cold spots approaching 50% of the prescription dose may occur along the matchline. Although abutting radiation fields have been investigated for static fields, there is no reported study regarding matching of tomographic IMRT and static fields. Compared to static fields, the matching of tomographic IMRT fields with static fields is more complicated. Since IMRT and static fields are planned on separate treatment planning computers, the dose in the abutment region is not specified. In addition, commonly used techniques for matching fields, such as feathering of junctions, are not practical. We have developed a method that substantially reduces dose inhomogeneity in the abutment region. In this method, a 'buffer zone' around the matchline was created and was included as part of the target for both IMRT and static field plans. In both fields, a small dose gradient (≤3%/mm) in the buffer zone was created. In the IMRT plan, the buffer zone was divided into three sections with dose varying from 83% to 25% of prescription dose. The static field dose profile was modified using either a specially designed physical (hard) or a dynamic (soft) wedge. When these modified fields were matched, the combined dose in the abutment region varied by ≤10% in the presence of setup errors spanning 4 mm (±2 mm) when the hard wedge was used and 10 mm (±5 mm) with the soft wedge

  12. Monte Carlo simulations to replace film dosimetry in IMRT verification

    International Nuclear Information System (INIS)

    Goetzfried, Thomas; Trautwein, Marius; Koelbi, Oliver; Bogner, Ludwig; Rickhey, Mark

    2011-01-01

    Patient-specific verification of intensity-modulated radiation therapy (IMRT) plans can be done by dosimetric measurements or by independent dose or monitor unit calculations. The aim of this study was the clinical evaluation of IMRT verification based on a fast Monte Carlo (MC) program with regard to possible benefits compared to commonly used film dosimetry. 25 head-and-neck IMRT plans were recalculated by a pencil beam based treatment planning system (TPS) using an appropriate quality assurance (QA) phantom. All plans were verified both by film and diode dosimetry and compared to MC simulations. The irradiated films, the results of diode measurements and the computed dose distributions were evaluated, and the data were compared on the basis of gamma maps and dose-difference histograms. Average deviations in the high-dose region between diode measurements and point dose calculations performed with the TPS and MC program were 0.7 ± 2.7% and 1.2 ± 3.1%, respectively. For film measurements, the mean gamma values with 3% dose difference and 3 mm distance-to-agreement were 0.74 ± 0.28 (TPS as reference) with dose deviations up to 10%. Corresponding values were significantly reduced to 0.34 ± 0.09 for MC dose calculation. The total time needed for both verification procedures is comparable, however, by far less labor intensive in the case of MC simulations. The presented study showed that independent dose calculation verification of IMRT plans with a fast MC program has the potential to eclipse film dosimetry more and more in the near future. Thus, the linac-specific QA part will necessarily become more important. In combination with MC simulations and due to the simple set-up, point-dose measurements for dosimetric plausibility checks are recommended at least in the IMRT introduction phase. (orig.)

  13. Image guided IMRT dosimetry using anatomy specific MOSFET configurations.

    Science.gov (United States)

    Amin, Md Nurul; Norrlinger, Bern; Heaton, Robert; Islam, Mohammad

    2008-06-23

    We have investigated the feasibility of using a set of multiple MOSFETs in conjunction with the mobile MOSFET wireless dosimetry system, to perform a comprehensive and efficient quality assurance (QA) of IMRT plans. Anatomy specific MOSFET configurations incorporating 5 MOSFETs have been developed for a specially designed IMRT dosimetry phantom. Kilovoltage cone beam computed tomography (kV CBCT) imaging was used to increase the positional precision and accuracy of the detectors and phantom, and so minimize dosimetric uncertainties in high dose gradient regions. The effectiveness of the MOSFET based dose measurements was evaluated by comparing the corresponding doses measured by an ion chamber. For 20 head and neck IMRT plans the agreement between the MOSFET and ionization chamber dose measurements was found to be within -0.26 +/- 0.88% and 0.06 +/- 1.94% (1 sigma) for measurement points in the high dose and low dose respectively. A precision of 1 mm in detector positioning was achieved by using the X-Ray Volume Imaging (XVI) kV CBCT system available with the Elekta Synergy Linear Accelerator. Using the anatomy specific MOSFET configurations, simultaneous measurements were made at five strategically located points covering high dose and low dose regions. The agreement between measurements and calculated doses by the treatment planning system for head and neck and prostate IMRT plans was found to be within 0.47 +/- 2.45%. The results indicate that a cylindrical phantom incorporating multiple MOSFET detectors arranged in an anatomy specific configuration, in conjunction with image guidance, can be utilized to perform a comprehensive and efficient quality assurance of IMRT plans.

  14. The number of beams in IMRT-theoretical investigations and implications for single-arc IMRT

    International Nuclear Information System (INIS)

    Bortfeld, Thomas

    2010-01-01

    The first purpose of this paper is to shed some new light on the old question of selecting the number of beams in intensity-modulated radiation therapy (IMRT). The second purpose is to illuminate the related issue of discrete static beam angles versus rotational techniques, which has recently re-surfaced due to the advancement of volumetric modulated arc therapy (VMAT). A specific objective is to find analytical expressions that allow one to address the points raised above. To make the problem mathematically tractable, it is assumed that the depth dose is flat and that the lateral dose profile can be approximated by polynomials, specifically Chebyshev polynomials of the first kind, of finite degree. The application of methods known from image reconstruction then allows one to answer the first question above as follows: the required number of beams is determined by the maximum degree of the polynomials used in the approximation of the beam profiles, which is a measure of the dose variability. There is nothing to be gained by using more beams. In realistic cases, in which the variability of the lateral dose profile is restricted in several ways, the required number of beams is of the order of 10-20. The consequence of delivering the beams with a 'leaf sweep' technique during continuous rotation of the gantry, as in VMAT, is also derived in an analytical form. The main effect is that the beams fan out, but the effect near the axis of rotation is small. This result can serve as a theoretical justification of VMAT. Overall the analytical derivations in this paper, albeit based on strong simplifications, provide new insights into, and a deeper understanding of, the beam angle problem in IMRT. The decomposition of the beam profiles into well-behaved and easily deliverable smooth functions, such as Chebyshev polynomials, could be of general interest in IMRT treatment planning.

  15. Automatic learning-based beam angle selection for thoracic IMRT

    International Nuclear Information System (INIS)

    Amit, Guy; Marshall, Andrea; Purdie, Thomas G.; Jaffray, David A.; Levinshtein, Alex; Hope, Andrew J.; Lindsay, Patricia; Pekar, Vladimir

    2015-01-01

    Purpose: The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner’s clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. Methods: The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. Results: The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume

  16. Incorporating prior knowledge into beam orientation optimization in IMRT

    International Nuclear Information System (INIS)

    Pugachev, Andrei M.S.; Lei Xing

    2002-01-01

    Purpose: Selection of beam configuration in currently available intensity-modulated radiotherapy (IMRT) treatment planning systems is still based on trial-and-error search. Computer beam orientation optimization has the potential to improve the situation, but its practical implementation is hindered by the excessive computing time associated with the calculation. The purpose of this work is to provide an effective means to speed up the beam orientation optimization by incorporating a priori geometric and dosimetric knowledge of the system and to demonstrate the utility of the new algorithm for beam placement in IMRT. Methods and Materials: Beam orientation optimization was performed in two steps. First, the quality of each possible beam orientation was evaluated using beam's-eye-view dosimetrics (BEVD) developed in our previous study. A simulated annealing algorithm was then employed to search for the optimal set of beam orientations, taking into account the BEVD scores of different incident beam directions. During the calculation, sampling of gantry angles was weighted according to the BEVD score computed before the optimization. A beam direction with a higher BEVD score had a higher probability of being included in the trial configuration, and vice versa. The inclusion of the BEVD weighting in the stochastic beam angle sampling process made it possible to avoid spending valuable computing time unnecessarily at 'bad' beam angles. An iterative inverse treatment planning algorithm was used for beam intensity profile optimization during the optimization process. The BEVD-guided beam orientation optimization was applied to an IMRT treatment of paraspinal tumor. The advantage of the new optimization algorithm was demonstrated by comparing the calculation with the conventional scheme without the BEVD weighting in the beam sampling. Results: The BEVD tool provided useful guidance for the selection of the potentially good directions for the beams to incident and was used

  17. Fluence complexity for IMRT field and simplification of IMRT verification

    International Nuclear Information System (INIS)

    Hanushova, Tereza; Vondarchek, Vladimir

    2013-01-01

    Intensity Modulated Radiation Therapy (IMRT) requires dosimetric verification of each patient’s plan, which is time consuming. This work deals with the idea of minimizing the number of fields for control, or even replacing plan verification by machine quality assurance (QA). We propose methods for estimation of fluence complexity in an IMRT field based on dose gradients and investigate the relation between results of gamma analysis and this quantity. If there is a relation, it might be possible to only verify the most complex field of a plan. We determine the average fluence complexity in clinical fields and design a test fluence corresponding to this amount of complexity which might be used in daily QA and potentially replace patient-related verification. Its applicability is assessed in clinical practice. The relation between fluence complexity and results of gamma analysis has been confirmed for plans but not for single fields. There is an agreement between the suggested test fluence and clinical fields in the average gamma parameter. A critical value of average gamma has been specified for the test fluence as a criterion for distinguishing between poorly and well deliverable plans. It will not be possible to only verify the most complex field of a plan but verification of individual plans could be replaced by a morning check of the suggested test fluence, together with a well-established set of QA tests. (Author)

  18. Synchronous meningioma and anaplastic large cell lymphoma.

    Science.gov (United States)

    Colen, Chaim B; Rayes, Mahmoud; Kupsky, William J; Guthikonda, Murali

    2010-06-01

    Synchronous primary brain tumors are exceedingly rare. When they occur, most cases are associated with metastatic disease. To the best of our knowledge, we report the first case of an atypical meningioma infiltrated by a T-cell-primary central nervous system lymphoma (PCNSL), specifically anaplastic large cell lymphoma (ALCL). We present a novel, unifying, plausible mechanism for its origin based on theories in the current literature. A 65-year-old man with a history of near-total resection of atypical meningioma presented with a complaint of progressive headaches. Imaging revealed recurrent tumor. Left frontal-temporal craniotomy with near-total tumor resection followed by radiation was performed. Recurrent symptomatic tumor led to repeat left frontotemporal craniotomy with tumor resection and partial anterior temporal lobectomy. Part of the specimen showed predominantly fibrotic neoplasm composed of nests and whorls of meningothelial cells, highlighted by epithelial membrane antigen (EMA) staining. The remainder of the specimen consisted of densely cellular neoplasm centered in connective tissue, including areas involved by meningioma. This tumor was composed of moderately large lymphoid cells with large nuclei, prominent nucleoli, and amphophilic cytoplasm. These cells were strongly immunoreactive for CD3 and CD30 but remained unstained with EMA, anaplastic lymphoma kinase-1 (ALK-1), CD15 or cytotoxic associated antigen TIA-1. Smaller mature lymphocytes, chiefly T-cells, were intermixed. The morphologic and immunohistochemical features were considered typical of anaplastic large T-cell lymphoma. The pathogenesis of this association may have been due to radiation-mediated breakdown of the blood-brain barrier with subsequent T-cell infiltration and proliferation. We advocate aggressive resection and long-term surveillance for individuals with metastasis, especially higher-grade neoplasms that receive radiotherapy.

  19. Embolisation of intracranial meningiomas without subsequent surgery

    International Nuclear Information System (INIS)

    Bendszus, M.; Solymosi, L.; Martin-Schrader, I.; Schlake, H.P.

    2003-01-01

    In an open, prospective study, we embolised intracranial meningiomas in seven patients, without subsequent surgery. Follow-up over a mean of 20 months included serial neurological examination, MRI and MR spectroscopy. Clinically, embolisation had no adverse effects. Symptomatic patients showed clinical improvement. On MRI marked tumour shrinkage occurred after embolisation in six patients, and was most pronounced during the first 6 months. In a young boy the tumour was unchanged despite complete angiographic devascularisation. Embolisation without subsequent surgery may cause substantial tumour shrinkage and thus be used in selected in patients. However, thorough follow-up is mandatory to ascertain the effects of embolisation. (orig.)

  20. Radiation for skull base meningiomas: review of the literature on the approach to radiotherapy.

    Science.gov (United States)

    Moraes, Fabio Y; Chung, Caroline

    2017-07-01

    Skull base meningiomas (SBM) pose unique challenges for radiotherapy as these tumors are often in close proximity to a number of critical structures and may not be surgically addressed in many cases, leaving the question about the tumor grade and expected biological behaviour. External beam radiotherapy and radiosurgery are longstanding treatments for meningioma that are typically used as upfront primary therapy, for recurrent tumors and as adjuvant therapy following surgical resection. There is controversy regarding the optimal timing and approach for radiation therapy in various clinical settings such as the role of adjuvant radiotherapy for completely resected grade 2 tumours. Despite the use of radiotherapy for many decades, the evidence to guide optimal radiation treatment is limited largely to single institution series of EBRT, SRS and particle therapy. In this article, we review the published data to clarify the role of external beam radiotherapy, proton radiotherapy and single and multi-fraction radiosurgery for SBM. We also highlight the areas of potential research and need for clinical improvement, including the growing awareness and effort to improve cognitive function in this patient population, who typically have long life expectancy following their meningioma diagnosis.

  1. Effect of the positioning of the blades in MRT treatments; Efecto del posicionamiento de las laminas en los tratamientos de IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz de Zarate Vivanco, R.; Perez Azorin, J. F.; Casquero Ocio, F.; Trueba Garayo, I.

    2013-07-01

    The attenuation of the beams of radiation that cross the treatment table is a verifiable fact that should be incorporated into the planning of the radiation treatments, especially in advanced techniques. (Author)

  2. Variable beam dose rate and DMLC IMRT to moving body anatomy

    International Nuclear Information System (INIS)

    Papiez, Lech; Abolfath, Ramin M.

    2008-01-01

    Derivation of formulas relating leaf speeds and beam dose rates for delivering planned intensity profiles to static and moving targets in dynamic multileaf collimator (DMLC) intensity modulated radiation therapy (IMRT) is presented. The analysis of equations determining algorithms for DMLC IMRT delivery under a variable beam dose rate reveals a multitude of possible delivery strategies for a given intensity map and for any given target motion patterns. From among all equivalent delivery strategies for DMLC IMRT treatments specific subclasses of strategies can be selected to provide deliveries that are particularly suitable for clinical applications providing existing delivery devices are used. Special attention is devoted to the subclass of beam dose rate variable DMLC delivery strategies to moving body anatomy that generalize existing techniques of such deliveries in Varian DMLC irradiation methodology to static body anatomy. Few examples of deliveries from this subclass of DMLC IMRT irradiations are investigated to illustrate the principle and show practical benefits of proposed techniques.

  3. Variable beam dose rate and DMLC IMRT to moving body anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Papiez, Lech; Abolfath, Ramin M. [Department of Radiation Oncology, UTSouthwestern Medical Center, Dallas, Texas 75390 (United States)

    2008-11-15

    Derivation of formulas relating leaf speeds and beam dose rates for delivering planned intensity profiles to static and moving targets in dynamic multileaf collimator (DMLC) intensity modulated radiation therapy (IMRT) is presented. The analysis of equations determining algorithms for DMLC IMRT delivery under a variable beam dose rate reveals a multitude of possible delivery strategies for a given intensity map and for any given target motion patterns. From among all equivalent delivery strategies for DMLC IMRT treatments specific subclasses of strategies can be selected to provide deliveries that are particularly suitable for clinical applications providing existing delivery devices are used. Special attention is devoted to the subclass of beam dose rate variable DMLC delivery strategies to moving body anatomy that generalize existing techniques of such deliveries in Varian DMLC irradiation methodology to static body anatomy. Few examples of deliveries from this subclass of DMLC IMRT irradiations are investigated to illustrate the principle and show practical benefits of proposed techniques.

  4. From analytic inversion to contemporary IMRT optimization: radiation therapy planning revisited from a mathematical perspective.

    Science.gov (United States)

    Censor, Yair; Unkelbach, Jan

    2012-04-01

    In this paper we look at the development of radiation therapy treatment planning from a mathematical point of view. Historically, planning for Intensity-Modulated Radiation Therapy (IMRT) has been considered as an inverse problem. We discuss first the two fundamental approaches that have been investigated to solve this inverse problem: Continuous analytic inversion techniques on one hand, and fully-discretized algebraic methods on the other hand. In the second part of the paper, we review another fundamental question which has been subject to debate from the beginning of IMRT until the present day: The rotation therapy approach versus fixed angle IMRT. This builds a bridge from historic work on IMRT planning to contemporary research in the context of Intensity-Modulated Arc Therapy (IMAT). Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  5. Inverse vs. forward breast IMRT planning

    International Nuclear Information System (INIS)

    Mihai, Alina; Rakovitch, Eileen; Sixel, Katharina; Woo, Tony; Cardoso, Marlene; Bell, Chris; Ruschin, Mark; Pignol, Jean-Philippe

    2005-01-01

    Breast intensity-modulated radiation therapy (IMRT) improves dose distribution homogeneity within the whole breast. Previous publications report the use of inverse or forward dose optimization algorithms. Because the inverse technique is not widely available in commercial treatment planning systems, it is important to compare the 2 algorithms. The goal of this work is to compare them on a prospective cohort of 30 patients. Dose distributions were evaluated on differential dose-volume histograms using the volumes receiving more than 105% (V 105 ) and 110% (V 110 ) of the prescribed dose, and on the maximum dose (D max ) or hot spot and the sagittal dose gradient (SDG) being the gradient between the dose on inframammary crease and the dose prescribed. The data were analyzed using Wilcoxon signed rank test. The inverse planning significantly improves the V 105 (mean value 9.7% vs. 14.5%, p = 0.002), and the V 110 (mean value 1.4% vs. 3.2%, p = 0.006). However, the SDG is not statistically significantly different for either algorithm. Looking at the potential impact on skin acute reaction, although there is a significant reduction of V 110 using an inverse algorithm, it is unlikely this 1.6% volume reduction will present a significant clinical advantage over a forward algorithm. Both algorithms are equivalent in removing the hot spots on the inframammary fold, where acute skin reactions occur more frequently using a conventional wedge technique. Based on these results, we recommend that both forward and inverse algorithms should be considered for breast IMRT planning

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    Purpose: To determine whether intensity-modulated radiotherapy (IMRT) treatment increases the total integral dose of nontarget tissue relative to the conventional three-dimensional conformal radiotherapy (3D-CRT) technique for high-grade gliomas. Methods and Materials: Twenty patients treated with 3D-CRT for glioblastoma multiforme were selected for a comparative dosimetric evaluation with IMRT. Original target volumes, organs at risk (OAR), and dose-volume constraints were used for replanning with IMRT. Predicted isodose distributions, cumulative dose-volume histograms of target volumes and OAR, normal tissue integral dose, target coverage, dose conformity, and normal tissue sparing with 3D-CRT and IMRT planning were compared. Statistical analyses were performed to determine differences. Results: In all 20 patients, IMRT maintained equivalent target coverage, impro