Limits...
Dosimetric evaluation of an ipsilateral intensity modulated radiotherapy beam arrangement for parotid malignancies.

Yirmibesoglu E, Fried DV, Kostich M, Rosenman J, Shockley W, Weissler M, Zanation A, Chera B - Radiol Oncol (2013)

Bottom Line: Dose, volume statistics for the planning target volumes (PTVs) and planning risk volumes (PRVs) were compared for the four treatment techniques.Wedge pair plans inadequately covered the deep aspect of the PTV.The mean doses to the brainstem, spinal cord, ipsilateral temporal lobe, cerrebellum and ipsilateral cochlea were similar among the four techniques.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey ; Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, NC, USA.

ABSTRACT

Background: We conducted a dosimetric comparison of an ipsilateral beam arrangement for intensity modulated radiotherapy (IMRT) with off-axis beams.

Patients and methods: Six patients who received post-operative radiotherapy (RT) for parotid malignancies were used in this dosimetric study. Four treatment plans were created for each CT data set (24 plans): 1) ipsilateral 4-field off-axis IMRT (4fld-OA), 2) conventional wedge pair (WP), 3) 7 field co-planar IMRT (7fld), and 4) ipsilateral co-planar 4-field quartet IMRT (4fld-CP). Dose, volume statistics for the planning target volumes (PTVs) and planning risk volumes (PRVs) were compared for the four treatment techniques.

Results: Wedge pair plans inadequately covered the deep aspect of the PTV. The 7-field IMRT plans delivered the largest low dose volumes to normal tissues. Mean dose to the contralateral parotid was highest for 7 field IMRT. Mean dose to the contralateral submandibular gland was highest for 7 field IMRT and WP. 7 field IMRT plans had the highest dose to the oral cavity. The mean doses to the brainstem, spinal cord, ipsilateral temporal lobe, cerrebellum and ipsilateral cochlea were similar among the four techniques.

Conclusions: For postoperative treatment of the parotid bed, 4-field ipsilateral IMRT techniques provided excellent coverage while maximally sparing the contralateral parotid gland and submandibular gland.

No MeSH data available.


Related in: MedlinePlus

Dose volume histograms of the contralateral parotid gland and contralateral submandibular gland for for wedge pair (WP), 7-field IMRT (7fld), 4-field co-plananr (4fld-CP), and 4-field off-axis (4fld-OA) IMRT plans.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3814288&req=5

f4-rado-47-04-411: Dose volume histograms of the contralateral parotid gland and contralateral submandibular gland for for wedge pair (WP), 7-field IMRT (7fld), 4-field co-plananr (4fld-CP), and 4-field off-axis (4fld-OA) IMRT plans.

Mentions: Dose volume data for the PRVs can be found in Table 3 and Figure 4 and 5. Due to the ipsilateral beam arrangement, the mean doses for the contralateral parotid gland, submandibular gland and cochleare lower in the wedge pair plan and 4-field IMRT plans. The mean dose and maximum dose to the ipsilateral cochlea are similar for all four plans. There is no clinically significant difference in the maximum dose and the volume receiving ≥60Gyto the brain, ipsilateral temporal lobe, and cerebellum. The maximum dose to the brainstem and cervical spinal cord were similar in all techniques. The mean dose to the oral cavity was highest for the 7 field IMRT plan and least for the 4 field IMRT plans.


Dosimetric evaluation of an ipsilateral intensity modulated radiotherapy beam arrangement for parotid malignancies.

Yirmibesoglu E, Fried DV, Kostich M, Rosenman J, Shockley W, Weissler M, Zanation A, Chera B - Radiol Oncol (2013)

Dose volume histograms of the contralateral parotid gland and contralateral submandibular gland for for wedge pair (WP), 7-field IMRT (7fld), 4-field co-plananr (4fld-CP), and 4-field off-axis (4fld-OA) IMRT plans.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3814288&req=5

f4-rado-47-04-411: Dose volume histograms of the contralateral parotid gland and contralateral submandibular gland for for wedge pair (WP), 7-field IMRT (7fld), 4-field co-plananr (4fld-CP), and 4-field off-axis (4fld-OA) IMRT plans.
Mentions: Dose volume data for the PRVs can be found in Table 3 and Figure 4 and 5. Due to the ipsilateral beam arrangement, the mean doses for the contralateral parotid gland, submandibular gland and cochleare lower in the wedge pair plan and 4-field IMRT plans. The mean dose and maximum dose to the ipsilateral cochlea are similar for all four plans. There is no clinically significant difference in the maximum dose and the volume receiving ≥60Gyto the brain, ipsilateral temporal lobe, and cerebellum. The maximum dose to the brainstem and cervical spinal cord were similar in all techniques. The mean dose to the oral cavity was highest for the 7 field IMRT plan and least for the 4 field IMRT plans.

Bottom Line: Dose, volume statistics for the planning target volumes (PTVs) and planning risk volumes (PRVs) were compared for the four treatment techniques.Wedge pair plans inadequately covered the deep aspect of the PTV.The mean doses to the brainstem, spinal cord, ipsilateral temporal lobe, cerrebellum and ipsilateral cochlea were similar among the four techniques.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey ; Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, NC, USA.

ABSTRACT

Background: We conducted a dosimetric comparison of an ipsilateral beam arrangement for intensity modulated radiotherapy (IMRT) with off-axis beams.

Patients and methods: Six patients who received post-operative radiotherapy (RT) for parotid malignancies were used in this dosimetric study. Four treatment plans were created for each CT data set (24 plans): 1) ipsilateral 4-field off-axis IMRT (4fld-OA), 2) conventional wedge pair (WP), 3) 7 field co-planar IMRT (7fld), and 4) ipsilateral co-planar 4-field quartet IMRT (4fld-CP). Dose, volume statistics for the planning target volumes (PTVs) and planning risk volumes (PRVs) were compared for the four treatment techniques.

Results: Wedge pair plans inadequately covered the deep aspect of the PTV. The 7-field IMRT plans delivered the largest low dose volumes to normal tissues. Mean dose to the contralateral parotid was highest for 7 field IMRT. Mean dose to the contralateral submandibular gland was highest for 7 field IMRT and WP. 7 field IMRT plans had the highest dose to the oral cavity. The mean doses to the brainstem, spinal cord, ipsilateral temporal lobe, cerrebellum and ipsilateral cochlea were similar among the four techniques.

Conclusions: For postoperative treatment of the parotid bed, 4-field ipsilateral IMRT techniques provided excellent coverage while maximally sparing the contralateral parotid gland and submandibular gland.

No MeSH data available.


Related in: MedlinePlus