Parotid Gland Function After Radiotherapy: The Combined Michigan and Utrecht Experience

Journal Article · Fri Oct 01 04:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.07.1708· OSTI ID:21436186

Dijkema, Tim ^[1]; Raaijmakers, Cornelis P.J. ^[1]; Ten Haken, Randall K ^[2]; Roesink, Judith M; Braam, Petra M; Houweling, Anette C; Moerland, Marinus A ^[1]; Eisbruch, Avraham ^[2]; Terhaard, Chris H.J. ^[1]

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1. Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands)
2. Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States)

Purpose: To analyze the combined and updated results from the University of Michigan and University Medical Center Utrecht on normal tissue complication probability (NTCP) of the parotid gland 1 year after radiotherapy (RT) for head-and-neck (HN) cancer. Patients and Methods: A total of 222 prospectively analyzed patients with various HN malignancies were treated with conventional and intensity-modulated RT. Stimulated individual parotid gland flow rates were measured before RT and 1 year after RT using Lashley cups at both centers. A flow ratio <25% of pretreatment was defined as a complication. The data were fitted to the Lyman-Kutcher-Burman model. Results: A total of 384 parotid glands (Michigan: 157; Utrecht: 227 glands) was available for analysis 1 year after RT. Combined NTCP analysis based on mean dose resulted in a TD{sub 50} (uniform dose leading to 50% complication probability) of 39.9 Gy and m (steepness of the curve) of 0.40. The resulting NTCP curve had good qualitative agreement with the combined clinical data. Mean doses of 25-30 Gy were associated with 17-26% NTCP. Conclusions: A definite NTCP curve for parotid gland function 1 year after RT is presented, based on mean dose. No threshold dose was observed, and TD{sub 50} was equal to 40 Gy.

• OSTI ID: 21436186
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 78; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BODY
DISEASES
DOSES
FLOW RATE
GLANDS
HEAD
MEDICINE
NECK
NEOPLASMS
NUCLEAR MEDICINE
ORGANS
RADIATION DOSES
RADIOLOGY
RADIOTHERAPY
THERAPY