Abstract
Objective: Prior studies have relied on CT to assess alterations in anatomy among patients undergoing radiation for head and neck cancer. We sought to determine the feasibility of using MRI-based image-guided radiotherapy to quantify these changes and to ascertain their potential dosimetric implications. Methods: 6 patients with head and neck cancer were treated with intensity-modulated radiotherapy (IMRT) on a novel tri-60Co teletherapy system equipped with a 0.35-T MRI (VR, ViewRay Incorporated, Oakwood Village, OH) to 66-70Gy in 33 fractions (fx). Pre-treatment MRIs on Fx 1, 5, 10, 15, 20, 25, 30 and 33 were imported into a contouring interface, where the primary gross tumour volume (GTV) and parotid glands were delineated. The centre of mass (COM) shifts for these structures were assessed relative to Day 1. Dosimetric data were co-registered with the MRIs, and doses to the GTV and parotid glands were assessed. Results: Primary GTVs decreased significantly over the course of IMRT (median % volume loss, 38.7%; range, 29.5-72.0%; p,0.05) at a median rate of 1.2%/ fx (range, 0.92-2.2%/fx). Both the ipsilateral and contralateral parotid glands experienced significant volume loss (p,0.05, for all) and shifted medially during IMRT. Weight loss correlated significantly with parotid gland volume loss and medial COM shift (p,0.05). Conclusion: Integrated on-board MRI can be used to accurately contour and analyze primary GTVs and parotid glands over the course of IMRT. COM shifts and significant volume reductions were observed, confirming the results of prior CT-based exercises.
| Original language | English (US) |
|---|---|
| Article number | 20160624 |
| Journal | British Journal of Radiology |
| Volume | 89 |
| Issue number | 1067 |
| DOIs | |
| State | Published - 2016 |
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ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
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Anatomic and dosimetric changes in patients with head and neck cancer treated with an integrated MRI-tri-60Co teletherapy device. / Raghavan, Govind; Kishan, Amar U.; Cao, Minsong; Chen, Allen M.
In: British Journal of Radiology, Vol. 89, No. 1067, 20160624, 2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Anatomic and dosimetric changes in patients with head and neck cancer treated with an integrated MRI-tri-60Co teletherapy device
AU - Raghavan, Govind
AU - Kishan, Amar U.
AU - Cao, Minsong
AU - Chen, Allen M.
PY - 2016
Y1 - 2016
N2 - Objective: Prior studies have relied on CT to assess alterations in anatomy among patients undergoing radiation for head and neck cancer. We sought to determine the feasibility of using MRI-based image-guided radiotherapy to quantify these changes and to ascertain their potential dosimetric implications. Methods: 6 patients with head and neck cancer were treated with intensity-modulated radiotherapy (IMRT) on a novel tri-60Co teletherapy system equipped with a 0.35-T MRI (VR, ViewRay Incorporated, Oakwood Village, OH) to 66-70Gy in 33 fractions (fx). Pre-treatment MRIs on Fx 1, 5, 10, 15, 20, 25, 30 and 33 were imported into a contouring interface, where the primary gross tumour volume (GTV) and parotid glands were delineated. The centre of mass (COM) shifts for these structures were assessed relative to Day 1. Dosimetric data were co-registered with the MRIs, and doses to the GTV and parotid glands were assessed. Results: Primary GTVs decreased significantly over the course of IMRT (median % volume loss, 38.7%; range, 29.5-72.0%; p,0.05) at a median rate of 1.2%/ fx (range, 0.92-2.2%/fx). Both the ipsilateral and contralateral parotid glands experienced significant volume loss (p,0.05, for all) and shifted medially during IMRT. Weight loss correlated significantly with parotid gland volume loss and medial COM shift (p,0.05). Conclusion: Integrated on-board MRI can be used to accurately contour and analyze primary GTVs and parotid glands over the course of IMRT. COM shifts and significant volume reductions were observed, confirming the results of prior CT-based exercises.
AB - Objective: Prior studies have relied on CT to assess alterations in anatomy among patients undergoing radiation for head and neck cancer. We sought to determine the feasibility of using MRI-based image-guided radiotherapy to quantify these changes and to ascertain their potential dosimetric implications. Methods: 6 patients with head and neck cancer were treated with intensity-modulated radiotherapy (IMRT) on a novel tri-60Co teletherapy system equipped with a 0.35-T MRI (VR, ViewRay Incorporated, Oakwood Village, OH) to 66-70Gy in 33 fractions (fx). Pre-treatment MRIs on Fx 1, 5, 10, 15, 20, 25, 30 and 33 were imported into a contouring interface, where the primary gross tumour volume (GTV) and parotid glands were delineated. The centre of mass (COM) shifts for these structures were assessed relative to Day 1. Dosimetric data were co-registered with the MRIs, and doses to the GTV and parotid glands were assessed. Results: Primary GTVs decreased significantly over the course of IMRT (median % volume loss, 38.7%; range, 29.5-72.0%; p,0.05) at a median rate of 1.2%/ fx (range, 0.92-2.2%/fx). Both the ipsilateral and contralateral parotid glands experienced significant volume loss (p,0.05, for all) and shifted medially during IMRT. Weight loss correlated significantly with parotid gland volume loss and medial COM shift (p,0.05). Conclusion: Integrated on-board MRI can be used to accurately contour and analyze primary GTVs and parotid glands over the course of IMRT. COM shifts and significant volume reductions were observed, confirming the results of prior CT-based exercises.
UR - http://www.scopus.com/inward/record.url?scp=84994092043&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84994092043&partnerID=8YFLogxK
U2 - 10.1259/bjr.20160624
DO - 10.1259/bjr.20160624
M3 - Article
AN - SCOPUS:84994092043
VL - 89
JO - British Journal of Radiology
JF - British Journal of Radiology
SN - 0007-1285
IS - 1067
M1 - 20160624
ER -