TY - JOUR
T1 - Magnetic resonance guided elective neck irradiation targeting individual lymph nodes
T2 - A new concept
AU - Reinders, Floris C.J.
AU - Heijst, Tristan C.F.van
AU - Mases, Joel
AU - Terhaard, Chris H.J.
AU - Doornaert, Patricia A.H.
AU - Philippens, Marielle E.P.
AU - Raaijmakers, Cornelis P.J.
N1 - Funding Information:
We would like to thank Erik Brand for his contributions to the treatment planning of this new treatment concept and we would like to thank Bas Meyer Viol for MRI sequence optimization.
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/10
Y1 - 2021/10
N2 - Background and purpose: Conventional elective neck irradiation (ENI) in head and neck cancer consists of radiotherapy (RT) to the regional lymph node (LN) levels contoured on computed tomography. Hybrid Magnetic Resonance (MR) - RT modalities, such as combined magnetic resonance imaging - linear accelerators (MRLs), might enable new ENI strategies in which individual non-suspect lymph nodes (i-LNs) are targeted. In this treatment planning study, new MR-based strategies targeting i-LNs (i-ENI) were compared to conventional treatment. Materials and methods: All i-LNs were delineated on MR images of ten retrospectively selected patients with T2-4aN0M0 laryngeal cancer. Three strategies were considered. Strategy A: Conventional ENI delivered with a conventional linear accelerator (35x 1.55 Gy). Strategy B: MRL-based i-ENI (35x 1.55 Gy) to the individual lymph nodes including a background dose to the conventional elective neck volumes (35x 1.03 Gy). Strategy C: Same as Strategy B, but without background dose. In all plans the dose prescription to the primary tumor was 35x 2 Gy. Mean dose (Dmean) reductions in the organs at risk (OAR) were compared using the Wilcoxon signed rank test. Results: Compared to conventional ENI (strategy A), significant Dmean reductions of 6.0 Gy and 8.0 Gy were observed in the submandibular glands, of 9.4 Gy and 13 Gy in the carotid arteries and of 9.9 Gy and 19.4 Gy in the thyroid for strategy B and C, respectively. Large inter-patient variations of Dmean reductions were observed in all OARs. Conclusion: MRL-based i-ENI is a new promising concept that could reduce the mean dose to OARs in the neck significantly for patients with laryngeal cancer.
AB - Background and purpose: Conventional elective neck irradiation (ENI) in head and neck cancer consists of radiotherapy (RT) to the regional lymph node (LN) levels contoured on computed tomography. Hybrid Magnetic Resonance (MR) - RT modalities, such as combined magnetic resonance imaging - linear accelerators (MRLs), might enable new ENI strategies in which individual non-suspect lymph nodes (i-LNs) are targeted. In this treatment planning study, new MR-based strategies targeting i-LNs (i-ENI) were compared to conventional treatment. Materials and methods: All i-LNs were delineated on MR images of ten retrospectively selected patients with T2-4aN0M0 laryngeal cancer. Three strategies were considered. Strategy A: Conventional ENI delivered with a conventional linear accelerator (35x 1.55 Gy). Strategy B: MRL-based i-ENI (35x 1.55 Gy) to the individual lymph nodes including a background dose to the conventional elective neck volumes (35x 1.03 Gy). Strategy C: Same as Strategy B, but without background dose. In all plans the dose prescription to the primary tumor was 35x 2 Gy. Mean dose (Dmean) reductions in the organs at risk (OAR) were compared using the Wilcoxon signed rank test. Results: Compared to conventional ENI (strategy A), significant Dmean reductions of 6.0 Gy and 8.0 Gy were observed in the submandibular glands, of 9.4 Gy and 13 Gy in the carotid arteries and of 9.9 Gy and 19.4 Gy in the thyroid for strategy B and C, respectively. Large inter-patient variations of Dmean reductions were observed in all OARs. Conclusion: MRL-based i-ENI is a new promising concept that could reduce the mean dose to OARs in the neck significantly for patients with laryngeal cancer.
KW - Head and neck neoplasms
KW - Lymph nodes
KW - Magnetic resonance imaging
KW - Radiotherapy
KW - Squamous cell carcinoma of head and neck
UR - http://www.scopus.com/inward/record.url?scp=85118849363&partnerID=8YFLogxK
U2 - 10.1016/j.phro.2021.10.006
DO - 10.1016/j.phro.2021.10.006
M3 - Article
C2 - 35169639
AN - SCOPUS:85118849363
SN - 2405-6316
VL - 20
SP - 76
EP - 81
JO - Physics and Imaging in Radiation Oncology
JF - Physics and Imaging in Radiation Oncology
ER -