Application of the No Action Level (NAL) protocol to correct for prostate motion based on electronic portal imaging of implanted markers

Boer, Hans C.J. de; Os, Marjolein J.H. van; Jansen, Peter P.; Heijmen, B.

doi:10.1016/j.ijrobp.2004.09.035

Cited by 96 publications

(56 citation statements)

References 48 publications

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“…There was no indication of either prostate swelling (increased separation of markers) or shrinking (decreased separation of markers) which might have been caused by prostate swelling or constriction due to radiotherapy or continual hormone therapy respectively. Where the position of the markers within the prostate has been stated in other studies it is either in both lobes and apex, when there were 3 markers used (27,19), or at the base and the apex (40,41,20,22). Only one study was specific in stating that the markers should be at some distance from the rectal wall and urethra (11) which is in accordance of our experience.…”

Section: Discussionsupporting

confidence: 77%

A Comparison of the Use of Bony Anatomy and Internal Markers for Offline Verification and an Evaluation of the Potential Benefit of Online and Offline Verification Protocols for Prostate Radiotherapy

McNair

Hansen

Parker

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

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Section: Discussionsupporting

confidence: 77%

A Comparison of the Use of Bony Anatomy and Internal Markers for Offline Verification and an Evaluation of the Potential Benefit of Online and Offline Verification Protocols for Prostate Radiotherapy

McNair

Hansen

Parker

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

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“…Mean shifts were calculated from these data and were applied for the subsequent treatments without imaging. This is similar to the nonaction level (NAL) protocol described by de Boer et al 12 , 13 , 14 …”

Section: Methodsmentioning

confidence: 79%

“…In order to determine the magnitude of the residual alignment errors and the feasibility of implementing an off‐line verification protocol 12 , 13 to reduce the imaging workload, several OVP were simulated retrospectively using the daily positioning data.…”

Section: Methodsmentioning

confidence: 99%

A retrospective tomotherapy image‐guidance study: analysis of more than 9,000 MVCT scans for ten different tumor sites

Sánchez-Rubio

Rodríguez-Romero

Castro

2014

J Applied Clin Med Phys

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The purpose of this study was to quantify the systematic and random errors for various disease sites when daily MVCT scans are acquired, and to analyze alternative off‐line verification protocols (OVP) with respect to the patient setup accuracy achieved. Alignment data from 389 patients (9,418 fractions) treated at ten different anatomic sites with daily image‐guidance (IG) on a helical tomotherapy unit were analyzed. Moreover, six OVP were retrospectively evaluated. For each OVP, the frequency of the residual setup errors and additional margins required were calculated for the treatment sessions without image guidance. The magnitude of the three‐dimensional vector displacement and its frequency were evaluated for all OVP. From daily IG, the main global systematic error was in the vertical direction (4.4–9.4 mm), and all rotations were negligible (less than 0.5°) for all anatomic sites. The lowest systematic and random errors were found for H&N and brain patients. All OVP were effective in reducing the mean systematic error to less than 1 mm and 0.2° in all directions and roll corrections for almost all treatment sites. The treatment margins needed to adapt the residual errors should be increased by 2–5 mm for brain and H&N, around 8 mm in the vertical direction for the other anatomic sites, and up to 19 mm in the longitudinal direction for abdomen patients. Almost 70% of the sessions presented a setup error of 3 mm for OVPs with an imaging frequency above 50%. Only for brain patients it would be feasible to apply an OVP because the residual setup error could be compensated for with a slight margin increase. However, daily imaging should be used for anatomic sites of difficult immobilization and/or large interfraction movement.PACS numbers: 87.55.‐x, 87.56.‐v

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“…Systematic and random displacements of the patient inside of the mask were analyzed using equations presented by de Boer et al (8). Briefly, the displacement of the 2 nd cervical vertebra (landmark for the patient's bony anatomy) relative to the external fiducial marks on the patient's mask was calculated for each repeat CT image set and is represented by d(p,f), where p is the patient number and f signifies the treatment fraction.…”

Section: Calculating Displacementmentioning

confidence: 99%

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

O’Daniel

Garden

Schwartz

et al. 2007

International Journal of Radiation Oncology*Biology*Physics

131

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Purpose-To quantify the differences between planned and delivered parotid gland and target doses, and to assess the benefits of daily bone alignment for head-and-neck cancer patients treated with intensity-modulated radiotherapy (IMRT).Methods and Materials-Eleven head-and-neck cancer patients received 2 CT scans/week with an in-room CT scanner over their course of radiotherapy. The clinical IMRT plans, designed with 3-4mm planning margins, were recalculated on the repeat CT images. The plans were aligned using (1) the actual treatment isocenter marked with radiopaque markers (BB) and (2) bone alignment to the cervical vertebrae to simulate image-guided setup. In-house deformable image registration software was used to map daily dose distributions to the original treatment plan and to calculate a cumulative, delivered dose distribution for each patient.Results-Using conventional BB alignment led to increases in the parotid gland mean dose above the planned dose by 5-7Gy in 45% of the patients (median = 3.0Gy ipsilateral (p=0.026); median = 1.0Gy contralateral (p=0.016)). Use of bone alignment led to reductions relative to BB alignment in 91% of patients (median=2Gy; range=0.3-8.3Gy; 15 of 22 parotids improved). However, the parotid dose from bone alignment was still greater than planned (median=1.0Gy (p=0.007)). Neither approach affected tumor dose coverage.Conclusions-With conventional BB alignment, the parotid gland mean dose was significantly increased above the planned mean dose. Using daily bone alignment reduced the parotid dose compared to BB alignment in almost all patients. A 3-4 mm planning margin was adequate for tumor dose coverage.Correspondence and reprint requests to:

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Application of the No Action Level (NAL) protocol to correct for prostate motion based on electronic portal imaging of implanted markers

Cited by 96 publications

References 48 publications

A Comparison of the Use of Bony Anatomy and Internal Markers for Offline Verification and an Evaluation of the Potential Benefit of Online and Offline Verification Protocols for Prostate Radiotherapy

A Comparison of the Use of Bony Anatomy and Internal Markers for Offline Verification and an Evaluation of the Potential Benefit of Online and Offline Verification Protocols for Prostate Radiotherapy

A retrospective tomotherapy image‐guidance study: analysis of more than 9,000 MVCT scans for ten different tumor sites

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

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