OBJECTIVE: This study evaluated and quantified the feasibility of submandibular gland (SMG) sparing in intensity-modulated radiotherapy (IMRT) for N0-stage nasopharyngeal carcinoma (NPC). METHODS: Ten patients with N0-stage NPC were enrolled in the study. Four IMRT plans were produced for each, with different limiting conditions. In plan A, SMG sparing was ignored; in plans B, C and D, the mean dose to SMGs was restricted to 39 Gy. In addition, at least 95% of planning target volume (PTV)-IIa (PTV of clinical target volume involving level IIa lymph node) in plan C and 90% of PTV-IIa in plan D were required to have a 60 Gy covering. RESULTS: The average mean dose to SMGs was 54.6 ± 3.6 Gy in plan A and was lower 39.3 ± 0.3, 49.3 ± 1.9 and 46.7 ± 2.8 Gy in plans B, C and D, respectively. The volume of PTV-IIa covered by 60 Gy was 98.9%, 81.6%, 95.2% and 90.8% in plans A, B, C and D, respectively, and showed a parallel association between dose reduction to SMGs and the covering deficit of PTV-IIa. CONCLUSION: Reducing the mean dose received by SMG to 39 Gy or less in IMRT for N0-stage NPC is feasible.
OBJECTIVE: This study evaluated and quantified the feasibility of submandibular gland (SMG) sparing in intensity-modulated radiotherapy (IMRT) for N0-stage nasopharyngeal carcinoma (NPC). METHODS: Ten patients with N0-stage NPC were enrolled in the study. Four IMRT plans were produced for each, with different limiting conditions. In plan A, SMG sparing was ignored; in plans B, C and D, the mean dose to SMGs was restricted to 39 Gy. In addition, at least 95% of planning target volume (PTV)-IIa (PTV of clinical target volume involving level IIa lymph node) in plan C and 90% of PTV-IIa in plan D were required to have a 60 Gy covering. RESULTS: The average mean dose to SMGs was 54.6 ± 3.6 Gy in plan A and was lower 39.3 ± 0.3, 49.3 ± 1.9 and 46.7 ± 2.8 Gy in plans B, C and D, respectively. The volume of PTV-IIa covered by 60 Gy was 98.9%, 81.6%, 95.2% and 90.8% in plans A, B, C and D, respectively, and showed a parallel association between dose reduction to SMGs and the covering deficit of PTV-IIa. CONCLUSION: Reducing the mean dose received by SMG to 39 Gy or less in IMRT for N0-stage NPC is feasible.
Authors: Anke Petra Jellema; Patricia Doornaert; Ben J Slotman; C Rene Leemans; Johannes A Langendijk Journal: Radiother Oncol Date: 2005-10-26 Impact factor: 6.280
Authors: Kauko Saarilahti; Mauri Kouri; Juhani Collan; Aki Kangasmäki; Timo Atula; Heikki Joensuu; Mikko Tenhunen Journal: Radiother Oncol Date: 2006-03-27 Impact factor: 6.280
Authors: A K Anand; J Jain; P S Negi; A R Chaudhoory; S N Sinha; P S Choudhury; R Kumar; R K Munjal Journal: Clin Oncol (R Coll Radiol) Date: 2006-08 Impact factor: 4.126