Correction of systematic set-up error in breast and head and neck irradiation through a no-action level (NAL) protocol

Lozano, Eva; Pérez, Luis Alfredo Carvajal; Torres, Javier; Carrascosa, Carmen; Sanz, Miguel León; Mendicote, Fermín; Gil, A. Nieto

doi:10.1007/s12094-011-0614-0

Cited by 16 publications

(16 citation statements)

References 39 publications

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“…10 Lozano reported CTV-PTV margin of 11.8 mm, 14.1 mm and 8.8 mm in the ML, CC and AP directions, respectively. 20 Since the difference in setup errors between a vac fix and routine positioning device is not large and positioning of patients on a vac-fix or alpha cradle either in isolation or in conjunction with a wing/breast board is limited by cost in our country where patients have to bear the expenses, we embarked on the usage of a wing board. A wing board allows relaxation and fixation of arms on a flat board with side wings and a neck support to rest the head and the time required for setup is shorter.…”

Section: Discussionmentioning

confidence: 99%

“…The CTV to PTV margin derived in our study is comparable to the literature for small breast. 20 An optimal setup image matching position in 2D orthogonal KV images was investigated by Laaksomaa et al 22 Residual errors in the treatment field images were determined by matching the orthogonal setup images to the vertebrae, sternum, ribs and their compromises. The best general image matching position was the compromise of the vertebrae, ribs and sternum and the worst was vertebra alone.…”

Section: Discussionmentioning

confidence: 99%

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Comparison of set-up errors by breast size on wing board by portal imaging

Raza

Agarwal

Das

et al. 2016

Reports of Practical Oncology & Radiotherapy

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Conclusion:Wing board can be used in a busy radiotherapy department for setting up breast patients with a margin of 1.1 cm, 0.76 cm and 0.71 cm for small breasts and 1.96 cm, 1.12 cm and 0.98 cm for large breast in the ML, AP and CC directions, respectively. The large PTV margin in the mediolateral direction in large breast can be reduced using NAL. Further research is needed to optimize positioning of large breasted women.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Comparison of set-up errors by breast size on wing board by portal imaging

Raza

Agarwal

Das

et al. 2016

Reports of Practical Oncology & Radiotherapy

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show abstract

“…Nevertheless, the methodology proposed in the present study does not require the same technical procedures and workload as daily on-line imaging verifications. Indeed, it allows correcting systematic errors and appropriate margin assessment [22][23][24]. We suggest a protocol with a 3 mm action level representing our daily clinical practice because if all the variances are less than 3 mm this typically corresponds to nearly one half of the usual planning risk volume (PRV) margin [20].…”

Section: Limitations and Special Considerationsmentioning

confidence: 99%

A prospective analysis of inter- and intrafractional errors to calculate CTV to PTV margins in head and neck patients

et al. 2014

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“…With Monte Carlo simulations they have shown that to halve the systematic setup error, the NAL protocol only requires 3–5 imaged fractions, while the SAL protocol needs 8–9 imaged fractions. Due to this superiority, the NAL protocol has an extensive application in WBRT with high resulting setup accuracy (6‐8) …”

Section: Introductionmentioning

confidence: 99%

Efficacy and workload analysis of a fixed vertical couch position technique and a fixed‐action–level protocol in whole‐breast radiotherapy

Petillion

Verhoeven

Weltens

et al. 2015

J Applied Clin Med Phys

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Quantification of the setup errors is vital to define appropriate setup margins preventing geographical misses. The no‐action–level (NAL) correction protocol reduces the systematic setup errors and, hence, the setup margins. The manual entry of the setup corrections in the record‐and‐verify software, however, increases the susceptibility of the NAL protocol to human errors. Moreover, the impact of the skin mobility on the anteroposterior patient setup reproducibility in whole‐breast radiotherapy (WBRT) is unknown. In this study, we therefore investigated the potential of fixed vertical couch position‐based patient setup in WBRT. The possibility to introduce a threshold for correction of the systematic setup errors was also explored. We measured the anteroposterior, mediolateral, and superior–inferior setup errors during fractions 1–12 and weekly thereafter with tangential angled single modality paired imaging. These setup data were used to simulate the residual setup errors of the NAL protocol, the fixed vertical couch position protocol, and the fixed‐action–level protocol with different correction thresholds. Population statistics of the setup errors of 20 breast cancer patients and 20 breast cancer patients with additional regional lymph node (LN) irradiation were calculated to determine the setup margins of each off‐line correction protocol. Our data showed the potential of the fixed vertical couch position protocol to restrict the systematic and random anteroposterior residual setup errors to 1.8 mm and 2.2 mm, respectively. Compared to the NAL protocol, a correction threshold of 2.5 mm reduced the frequency of mediolateral and superior–inferior setup corrections with 40% and 63%, respectively. The implementation of the correction threshold did not deteriorate the accuracy of the off‐line setup correction compared to the NAL protocol. The combination of the fixed vertical couch position protocol, for correction of the anteroposterior setup error, and the fixed‐action–level protocol with 2.5 mm correction threshold, for correction of the mediolateral and the superior–inferior setup errors, was proved to provide adequate and comparable patient setup accuracy in WBRT and WBRT with additional LN irradiation.PACS numbers: 87.53.Kn, 87.57.‐s

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Correction of systematic set-up error in breast and head and neck irradiation through a no-action level (NAL) protocol

Abstract: NAL off-line protocol is useful for systematic set-up error correction and PTV margin reduction in conventional breast and head and neck irradiation.

Cited by 16 publications

References 39 publications

Comparison of set-up errors by breast size on wing board by portal imaging

Comparison of set-up errors by breast size on wing board by portal imaging

A prospective analysis of inter- and intrafractional errors to calculate CTV to PTV margins in head and neck patients

Efficacy and workload analysis of a fixed vertical couch position technique and a fixed‐action–level protocol in whole‐breast radiotherapy

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