Experimental Determination of Peripheral Doses for Different IMRT Techniques Delivered by a Siemens Linear Accelerator

Wiezorek, Tilo; Voigt, Alexander; Metzger, Noreen; Georg, Dietmar; Schwedas, Michael; Salz, Henning; Wendt, Thomas

doi:10.1007/s00066-008-1743-4

Cited by 36 publications

(20 citation statements)

References 26 publications

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“…Dynamic beam delivery should reduce treatment time considerably [17], but at the price of the necessity to dispose of a specialized equipment. A study to determine if the risk of developing secondary cancers after qIMAT radiation differs from that associated with conventional IMRT is currently under way [23].…”

Section: Resultsmentioning

confidence: 99%

Quasi-IMAT Study with Conventional Equipment to Show High Plan Quality with a Single Gantry Arc

Alvarez-Moret

Kölbl²,

Bogner

2009

Strahlenther Onkol

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Section: Resultsmentioning

confidence: 99%

Quasi-IMAT Study with Conventional Equipment to Show High Plan Quality with a Single Gantry Arc

Alvarez-Moret

Kölbl²,

Bogner

2009

Strahlenther Onkol

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“…Hence, the clinical significance of low dose volumes for high-risk prostate cancer patients remains to be determined. Concerning neutron generation for photon energies > 8 MV, Wiezorek et al [30,31] determined experimentally that the neutron component at 15 MV is not negligible. Overall, our planning study indicates that there is no great advantage of 15 MV photons over 6 and 10 MV photons in large volume pelvic plans.…”

Section: Discussionmentioning

confidence: 99%

Effect of Photon-Beam Energy on VMAT and IMRT Treatment Plan Quality and Dosimetric Accuracy for Advanced Prostate Cancer

et al. 2011

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“…However, concerning neutron generation for photon energies .8 MV, it was demonstrated that the neutron component is not negligible at 15 MV. 34 Therefore, IMRT or VMAT delivery with low-energy photons may be adequate, since high-energy photons did not result in a significant benefit in terms of target coverage and OAR doses. Additionally, VMAT spares normal tissue surrounding the target volume better than IMRT; thus, rather than IMRT plans with higher energy, VMAT plans with lower energy may be a safe treatment strategy.…”

Section: Discussionmentioning

confidence: 99%

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

Onal¹,

Sonmez²,

Erbay³

et al. 2014

BJR

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Objective: This study compared the dosimetry of volumetric-arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) with a dynamic multileaf collimator using the Monte Carlo algorithm in the treatment of prostate cancer with and without simultaneous integrated boost (SIB) at different energy levels. Methods: The data of 15 biopsy-proven prostate cancer patients were evaluated. The prescribed dose was 78 Gy to the planning target volume (PTV78) including the prostate and seminal vesicles and 86 Gy (PTV86) in 39 fractions to the intraprostatic lesion, which was delineated by MRI or MR-spectroscopy. Results: PTV dose homogeneity was better for IMRT than VMAT at all energy levels for both PTV78 and PTV86. Lower rectum doses (V 30 -V 50 ) were significantly higher with SIB compared with PTV78 plans in both IMRT and VMAT plans at all energy levels. The bladder doses at high dose level (V 60 -V 80 ) were significantly higher in IMRT plans with SIB at all energy levels compared with PTV78 plans, but no significant difference was observed in VMAT plans. VMAT plans resulted in a significant decrease in the mean monitor units (MUs) for 6, 10, and 15 MV energy levels both in plans with and those without SIB. Conclusion: Dose escalation to intraprostatic lesions with 86 Gy is safe without causing serious increase in organs at risk (OARs) doses. VMAT is advantageous in sparing OARs and requiring less MU than IMRT. Advances in knowledge: VMAT with SIB to intraprostatic lesion is a feasible method in treating prostate cancer. Additionally, no dosimetric advantage of higher energy is observed.Randomized trials have shown a gain in biochemical relapse-free survival using dose escalation for prostate cancer.1 However, isolated local failure is still reported in nearly one-third of patients, even with higher radiotherapy (RT) doses.1 Local recurrence is of clinical importance because a relationship has been suggested between local control, distant metastasis and survival.2 It has also been demonstrated that intraprostatic failure mainly originates at the initial tumour location as a result of intrinsic resistance of a fraction of the tumour clones, which implies that selective dose escalation to the dominant intraprostatic lesion using simultaneous integrated boost (SIB) might be beneficial. With new RT techniques, such as intensity-modulated RT (IMRT) and volumetric-arc therapy (VMAT), SIB could be delivered without increasing acute toxicity.4-7 Several recent studies have performed dosimetric comparison of IMRT and VMAT plans in prostate cancer; 8-10 however, dosimetric evaluation of IMRT and VMAT plans delivering SIB is rare. In these studies, target volume and organs at risk (OARs) doses may vary with different treatment planning systems. Another aspect not often addressed in these planning studies is the photon energy level. 4,8,9,11 Although higher energy photons have the potential advantage of reduced attenuation with depth, this may in turn increase the risk of secondary malignancies because of the presence of neutron...

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Experimental Determination of Peripheral Doses for Different IMRT Techniques Delivered by a Siemens Linear Accelerator

Cited by 36 publications

References 26 publications

Quasi-IMAT Study with Conventional Equipment to Show High Plan Quality with a Single Gantry Arc

Quasi-IMAT Study with Conventional Equipment to Show High Plan Quality with a Single Gantry Arc

Effect of Photon-Beam Energy on VMAT and IMRT Treatment Plan Quality and Dosimetric Accuracy for Advanced Prostate Cancer

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

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