Initial experience with megavoltage (MV) CT guidance for daily prostate alignments

Langen, K; Zhang, Yashan; Andrews, Rhonda D.; Hurley, Monica E.; Meeks, Sanford L.; Poole, Darrell O.; Willoughby, Twyla R.; Kupelian, Patrick A.

doi:10.1016/j.ijrobp.2005.02.047

Cited by 146 publications

(73 citation statements)

References 21 publications

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“…Direct imaging of the prostate gland and daily verification of its position during each treatment session is essential for reducing the margins and, consequently, avoiding the organs at risk such as rectum and bladder. Several image guidance methods have been investigated in recent years, including tumor tracking with intraprostatic fiducial markers, cone‐beam computed tomography (CBCT), and ultrasound‐based imaging (US‐image guidance) 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 . Ultrasound‐based systems are volumetric and offer better soft‐tissue visualization compared to CBCT, without additional exposure to ionizing radiations (9) .…”

Section: Introductionmentioning

confidence: 99%

Impact of the observers' experience on daily prostate localization accuracy in ultrasound‐based IGRT with the Clarity platform

Fiandra

Guarneri

Muñoz

et al. 2014

J Applied Clin Med Phys

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The aim of this study is to evaluate the accuracy of daily prostate localization with ultrasound imaging of various radiation oncologists with nonhomogeneous expertise. For ten patients who underwent radical radiotherapy for localized prostate cancer, 11 radiation oncologists reviewed daily ultrasound scans acquired during three different treatment sessions. The average values of two senior radiation oncologists, considered to be expert observers, were selected as reference. The remaining nine observers were divided into two groups, Group 1 and Group 2, with more and less than one year of experience, respectively. The recorded shifts in prostate position were divided in three classes: <3 mm, 3–5 mm, and > 5 mm. Deviations from reference were less than 3 mm in all directions in 91% and 81% of measurements in Groups 1 and 2, respectively. The maximum difference in terms of root mean square error (RMSE) was reported for superior‐inferior (SI) direction, in particular a mean difference of 3.24 mm was observed for Group 2 in respect to the reference; moreover RMSE was 1 and 1.3 mm higher for Group 2 for anterior‐posterior (AP) and left‐right (LR) directions, respectively. The difference between Groups 1 and 2 was significant (p < 0.01) for all directions. The mean values for the shifts in all three directions between Group 1 and the references were 0.235 mm, 0.385 mm, and 0.009 mm for the LR, SI, and AP directions, respectively. The position of the prostate gland is more easily detectable (p.15em=.15em0.02) in the AP direction, while the visibility is lower for LR (p.15em=.15em0.02) and SI boundaries (p < 0.05). The observers' experience is essential for positioning the target correctly; therefore, a training period is recommended before putting the system into clinical practice.PACS number: 87.63.dh

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Section: Introductionmentioning

confidence: 99%

Impact of the observers' experience on daily prostate localization accuracy in ultrasound‐based IGRT with the Clarity platform

Fiandra

Guarneri

Muñoz

et al. 2014

J Applied Clin Med Phys

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“…Pre‐treatment MVCT images are beneficial in that they provide daily image guidance ( 38 ) and allow for calculation of the daily delivered dose. ( 39 ) It has been demonstrated that accurate deformable registration of daily MVCT and planning CT images permits the evaluation of accumulated dose distributions delivered over the coarse of treatment.…”

Section: Methodsmentioning

confidence: 99%

Assessment of a commercially available automatic deformable registration system

Fallone

Rivest

Riauka

et al. 2010

J Applied Clin Med Phys

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In recent years, a number of approaches have been applied to the problem of deformable registration validation. However, the challenge of assessing a commercial deformable registration system – in particular, an automatic registration system in which the deformable transformation is not readily accessible – has not been addressed. Using a collection of novel and established methods, we have developed a comprehensive, four‐component protocol for the validation of automatic deformable image registration systems over a range of IGRT applications. The protocol, which was applied to the Reveal‐MVS system, initially consists of a phantom study for determination of the system's general tendencies, while relative comparison of different registration settings is achieved through postregistration similarity measure evaluation. Synthetic transformations and contour‐based metrics are used for absolute verification of the system's intra‐modality and inter‐modality capabilities, respectively. Results suggest that the commercial system is more apt to account for global deformations than local variations when performing deformable image registration. Although the protocol was used to assess the capabilities of the Reveal‐MVS system, it can readily be applied to other commercial systems. The protocol is by no means static or definitive, and can be further expanded to investigate other potential deformable registration applications.PACS numbers: 87.19.xj, 87.56.Da, 87.57.nj

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“…Instead of choosing a fixed-beam setup, tomotherapy patients are treated with 51 equispaced beam directions per gantry rotation, which allows a much greater degree of freedom in the modulation because of the significant increase in the number of beamlets. 17,18 The tumor region was scanned on a daily basis, and positioning was done using the integrated registration with the planning CT. [19][20][21] Although a difference in resolution exists between kilovolt and MVCT images, the quality of MV imaging is sufficient for patient positioning. 22 Positioning was done both on bony and soft tissue anatomy and incorporated respiratory motion, because the MVCT procedure can be considered a ''slow'' CT. Daily MVCT allows the clinician to take into account any changes in internal anatomy that affect positioning based on tumor response during treatment.…”

Section: Radiotherapy Techniquementioning

confidence: 99%

Toxicity report of a phase 1/2 dose‐escalation study in patients with inoperable, locally advanced nonsmall cell lung cancer with helical tomotherapy and concurrent chemotherapy

Bral

Duchateau

Versmessen

et al. 2009

Cancer

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BACKGROUND:The objective of the current study was to evaluate the feasibility and toxicity of radiation dose escalation with concurrent chemotherapy using helical tomotherapy (HT) in patients with inoperable, locally advanced, stage III nonsmall cell lung cancer (LANSCLC) (grading determined according to the American Joint Committee on Cancer 6th edition grading system).METHODS:This phase 1/2 study was designed to determine the maximum tolerated dose (MTD) of radiotherapy in patients with LANSCLC administered concurrently with docetaxel and cisplatin. Radiotherapy was delivered using HT. A dose per fraction escalation was applied starting at 2 grays (Gy), with an increase of 6% per dose cohort (DC). The Radiation Therapy Oncology Group acute radiation morbidity score was used to monitor pulmonary, esophageal, and cardiac toxicity.RESULTS:Dose escalation was performed in 34 patients over 5 DCs to a dose per fraction of 2.48 Gy. No differences were observed in acute toxicity between the different DCs. However, a significant increase in late lung toxicity in DC IV, which received a fraction size of 2.36 Gy, necessitated a halt in further dose escalation with the MTD defined as 2.24 Gy per fraction. The overall incidence of acute grade ≥3 esophageal and pulmonary toxicity was 24% and 3%, respectively (grading determined according to the Radiation Therapy Oncology Group‐European Organisation for Research and Treatment of Cancer toxicity scoring system). The overall incidence of late lung toxicity was 21%, but the incidence was an acceptable 13% in DCs I, II, and III. The local response rate was 61% on computed tomography images.CONCLUSIONS:The use of HT to 67.2 Gy with concurrent cisplatin/docetaxel was feasible and resulted in acceptable toxicity. A full phase 2 study has been initiated to establish the true local response rate at the MTD of 2.24 Gy per fraction. Cancer 2010. © 2010 American Cancer Society.

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Initial experience with megavoltage (MV) CT guidance for daily prostate alignments

Cited by 146 publications

References 21 publications

Impact of the observers' experience on daily prostate localization accuracy in ultrasound‐based IGRT with the Clarity platform

Impact of the observers' experience on daily prostate localization accuracy in ultrasound‐based IGRT with the Clarity platform

Assessment of a commercially available automatic deformable registration system

Toxicity report of a phase 1/2 dose‐escalation study in patients with inoperable, locally advanced nonsmall cell lung cancer with helical tomotherapy and concurrent chemotherapy

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