Limits...
Determining leaf trajectories for dynamic multileaf collimators with consideration of marker visibility: an algorithm study.

Zhao B, Dai J - J. Radiat. Res. (2014)

Bottom Line: Compared with the initial solution, the Delta algorithm kept the total delivered intensities (TDIs) constant (without increasing the beam delivery time), but improved marker visibility (the percentage ratio of marker visibility time to beam delivery time).For the artificial fields (with three markers), marker visibility increased from 68.00-72.00% for a small field (5 × 5), from 38.46-43.59% for a medium field (10 × 10), and from 28.57-37.14% for a large field (20 × 20).For the 15 clinical fields, marker visibility increased 6-30% for eight fields and > 50% for two fields but did not change for five fields.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing 100034, China.

Show MeSH

Related in: MedlinePlus

The desired intensity matrix was taken as an example. The three markers (mA, mB and mC) were represented as squares located in the MLC leaf pairs A, B and C, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4202293&req=5

RRU035F7: The desired intensity matrix was taken as an example. The three markers (mA, mB and mC) were represented as squares located in the MLC leaf pairs A, B and C, respectively.

Mentions: To explain how the Delta algorithm works, we took the following simple intensity matrix as an example (see Fig. 7). Five active MLC leaf pairs were used to deliver a 2D intensity profile with a maximal intensity level of 10. Here, the three markers, denoted mA, mB and mC, were located in the leaf pairs A, B and C, respectively (the markers were represented as squares in Fig. 7). We assumed that the leaf step was 0.5 cm, the dose rate was 1 intensity/s and the leaf speed was 0.5 cm/s. The implementation of Delta algorithm for this example is as follows.


Determining leaf trajectories for dynamic multileaf collimators with consideration of marker visibility: an algorithm study.

Zhao B, Dai J - J. Radiat. Res. (2014)

The desired intensity matrix was taken as an example. The three markers (mA, mB and mC) were represented as squares located in the MLC leaf pairs A, B and C, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202293&req=5

RRU035F7: The desired intensity matrix was taken as an example. The three markers (mA, mB and mC) were represented as squares located in the MLC leaf pairs A, B and C, respectively.
Mentions: To explain how the Delta algorithm works, we took the following simple intensity matrix as an example (see Fig. 7). Five active MLC leaf pairs were used to deliver a 2D intensity profile with a maximal intensity level of 10. Here, the three markers, denoted mA, mB and mC, were located in the leaf pairs A, B and C, respectively (the markers were represented as squares in Fig. 7). We assumed that the leaf step was 0.5 cm, the dose rate was 1 intensity/s and the leaf speed was 0.5 cm/s. The implementation of Delta algorithm for this example is as follows.

Bottom Line: Compared with the initial solution, the Delta algorithm kept the total delivered intensities (TDIs) constant (without increasing the beam delivery time), but improved marker visibility (the percentage ratio of marker visibility time to beam delivery time).For the artificial fields (with three markers), marker visibility increased from 68.00-72.00% for a small field (5 × 5), from 38.46-43.59% for a medium field (10 × 10), and from 28.57-37.14% for a large field (20 × 20).For the 15 clinical fields, marker visibility increased 6-30% for eight fields and > 50% for two fields but did not change for five fields.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing 100034, China.

Show MeSH
Related in: MedlinePlus