Radiation Dose to the Brachial Plexus in Head-and-Neck Intensity-Modulated Radiation Therapy and Its Relationship to Tumor and Nodal Stage

Journal Article · Sat Sep 01 04:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.10.079· OSTI ID:22149462

Romesser, Paul B.; Qureshi, Muhammad M.; Kovalchuk, Nataliya; Orlina, Lawrence; Willins, John ^[1]

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1. Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States)

Purpose: The purpose of this retrospective study was to determine tumor factors contributing to brachial plexus (BP) dose in head-and-neck cancer (HNC) patients treated with intensity-modulated radiotherapy (IMRT) when the BP is routinely contoured as an organ at risk (OAR) for IMRT optimization. Methods and Materials: From 2004 to 2011, a total of 114 HNC patients underwent IMRT to a total dose of 69.96 Gy in 33 fractions, with the right and left BP prospectively contoured as separate OARs in 111 patients and the ipsilateral BP contoured in 3 patients (total, 225 BP). Staging category T4 and N2/3 disease were present in 34 (29.8%) and 74 (64.9%) patients, respectively. During IMRT optimization, the intent was to keep the maximum BP dose to {<=}60 Gy, but prioritizing tumor coverage over achieving the BP constraints. BP dose parameters were compared with tumor and nodal stage. Results: With a median follow-up of 16.2 months, 43 (37.7%) patients had {>=}24 months of follow-up with no brachial plexopathy reported. Mean BP volume was 8.2 {+-} 4.5 cm{sup 3}. Mean BP maximum dose was 58.1 {+-} 12.2 Gy, and BP mean dose was 42.2 {+-} 11.3 Gy. The BP maximum dose was {<=}60, {<=}66, and {<=}70 Gy in 122 (54.2%), 185 (82.2%), and 203 (90.2%) BP, respectively. For oropharynx, hypopharynx, and larynx sites, the mean BP maximum dose was 58.4 Gy and 63.4 Gy in T0-3 and T4 disease, respectively (p = 0.002). Mean BP maximum dose with N0/1 and N2/3 disease was 52.8 Gy and 60.9 Gy, respectively (p < 0.0001). Conclusions: In head-and-neck IMRT, dose constraints for the BP are difficult to achieve to {<=}60 to 66 Gy with T4 disease of the larynx, hypopharynx, and oropharynx or N2/3 disease. The risk of brachial plexopathy is likely very small in HNC patients undergoing IMRT, although longer follow-up is required.

• OSTI ID: 22149462
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 1 Vol. 84; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
HAZARDS
HEAD
LARYNX
NECK
NEOPLASMS
OPTIMIZATION
PATIENTS
RADIATION DOSES
RADIOTHERAPY