IMRT clinical implementation: Prostate and pelvic node irradiation using Helios and a 120‐leaf multileaf collimator

Clark, Catharine H.; Mubata, Cephas; Meehan, C.; Bidmead, A. Margaret; Staffurth, John; Humphreys, M.; Dearnaley, David P.

doi:10.1120/jacmp.v3i4.2551

Cited by 18 publications

(11 citation statements)

References 21 publications

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“…That observation is consistent with findings in earlier studies of imrt [25][26][27][28] . Of all activities, treatment delivery was the most costly-an observation that accords with findings reported in an abc study of imrt in Europe 27 .…”

Section: Discussionsupporting

confidence: 83%

Estimating the Costs of Intensity-Modulated and 3-Dimensional Conformal Radiotherapy in Ontario

et al. 2016

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Section: Discussionsupporting

confidence: 83%

Estimating the Costs of Intensity-Modulated and 3-Dimensional Conformal Radiotherapy in Ontario

et al. 2016

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“…Compared with localized fields, however, pelvic irradiation carries the risk of increasing adverse effects rates, in particular for the intestine (5)(6)(7)(8). Although the typical shape of the lymph node target calls for use of IMRT (with the planning target volume very close to the intestine), relatively few institutions have yet reported on the application of IMRT for this subset of prostate cancer patients (9)(10)(11)(12)(13)(14). We have implemented IMRT for this patient group with the aim of reducing the normal tissue doses and toxicity, in particular those related to intestine irradiation.…”

Section: Introductionmentioning

confidence: 99%

Intensity-Modulated Radiotherapy of Pelvic Lymph Nodes in Locally Advanced Prostate Cancer: Planning Procedures and Early Experiences

Muren

Wasbø

Helle

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

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Purpose: We present planning and early clinical outcomes of a study of intensity-modulated radiotherapy (IMRT) for locally advanced prostate cancer. Methods and Materials: A total of 43 patients initially treated with an IMRT plan delivering 50 Gy to the prostate, seminal vesicles, and pelvic lymph nodes, followed by a conformal radiotherapy (CRT) plan delivering 20 Gy to the prostate and seminal vesicles, were studied. Dose-volume histogram (DVH) data for the added plans were compared with dose-volume histogram data for the sum of two CRT plans for 15 cases. Gastrointestinal (GI) and genitourinary (GU) toxicity, based on the Radiation Therapy Oncology Group scoring system, was recorded weekly throughout treatment as well as 3 to 18 months after treatment and are presented. Results: Treatment with IMRT both reduced normal tissue doses and increased the minimum target doses. Intestine volumes receiving more than 40 and 50 Gy were significantly reduced (e.g., at 50 Gy, from 81 to 19 cm 3 ; p = 0.026), as were bladder volumes above 40, 50, and 60 Gy, rectum volumes above 30, 50, and 60 Gy, and hip joint muscle volumes above 20, 30, and 40 Gy. During treatment, Grade 2 GI toxicity was reported by 12 of 43 patients (28%), and Grade 2 to 4 GU toxicity was also observed among 12 patients (28%). With 6 to 18 months of follow-up, 2 patients (5%) experienced Grade 2 GI effects and 7 patients (16%) experienced Grade 2 GU effects. Conclusions: Use of IMRT for pelvic irradiation in prostate cancer reduces normal tissue doses, improves target coverage, and has a promising toxicity profile. Ó

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“…A lot of research and a vast number of publications exist on the subject of IMRT QA [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. IMRT is now also becoming standard practice in smaller, non-academic centres.…”

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confidence: 99%

Practical guidelines for routine intensity-modulated radiotherapy verification: pre-treatment verification with portal dosimetry and treatment verification within vivodosimetry

Vinall¹,

Williams²,

Currie³

et al. 2010

BJR

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ABSTRACT. The purpose of this work is to provide guidelines for the routine use of portal dosimetry and in vivo diode measurements to verify intensity-modulated radiotherapy (IMRT) treatments. To achieve tolerance levels that are sensitive enough to intercept problems, both the portal dosimetry and the in vivo procedure must be optimised. Portal dosimetry was improved by the introduction of an optimised twodimensional (2D) profile correction, which also accounted for the effect of backscatter from the R-arm. The scaled score, indicating the fraction of points not meeting the desired gamma evaluation criteria within the field opening, was determined as the parameter of interest. Using gamma criteria of a 3% dose difference and 3 mm distance to agreement, a ''scaled score'' threshold value of 1.5% was chosen to indicate excessive tongue and groove and other problems. The pre-treatment portal dosimetry quality assurance (QA) does not encompass verification of the patient dose calculation or position, and so it is complemented by in vivo diode measurements. Diode positioning is crucial in IMRT, and so we describe a method for diode positioning at any suitable point. We achieved 95% of IMRT field measurements within ¡5% and 99% within ¡8%, with improved accuracy being achieved over time owing to better positioning. Although the careful preparation and setup of the diode measurements can be time-consuming, this is compensated for by the time efficiency of the optimised procedure. Both methods are now easily absorbed into the routine work of the department. In many radiotherapy departments, routine treatment verification for conventional static treatment fields is performed during the first treatment session. This verification often consists of in vivo measurements with diodes (mostly on the beam axis) in combination with portal imaging of the treatment-field shapes superimposed on the patient's anatomy. Before the first treatment session, the treatment parameters are carefully reviewed by a qualified person and independent monitor unit (MU) calculations may be performed as an additional check.For dynamic intensity-modulated radiotherapy (IMRT) fields, a more extensive quality assurance (QA) protocol is considered to be good practice, the reasons for this being at least fourfold:(1) Both delivery and dose calculations are considerably more complex for dynamic IMRT fields than for conventional static fields.(2) Conventional portal imaging of the treatment fields provides images that are difficult to interpret because the modulated fluence is superimposed on the patient's anatomy.(3) Because of the presence of many dose gradients within the IMRT fields, conventional in vivo dosimetry on the beam axis is prone to large deviations, or can be meaningless when little dose is delivered on the beam axis.(4) Dosimetric treatment parameters, such as MU and multileaf collimator (MLC) shape (or movement pattern), depend on the individual patient plan and can vary substantially among patients as a function of the modulation. Hence,...

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IMRT clinical implementation: Prostate and pelvic node irradiation using Helios and a 120‐leaf multileaf collimator

Cited by 18 publications

References 21 publications

Estimating the Costs of Intensity-Modulated and 3-Dimensional Conformal Radiotherapy in Ontario

Estimating the Costs of Intensity-Modulated and 3-Dimensional Conformal Radiotherapy in Ontario

Intensity-Modulated Radiotherapy of Pelvic Lymph Nodes in Locally Advanced Prostate Cancer: Planning Procedures and Early Experiences

Practical guidelines for routine intensity-modulated radiotherapy verification: pre-treatment verification with portal dosimetry and treatment verification within vivodosimetry

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