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Purpose. To investigate the clinical outcomes and feasibility of combined conventional radiation therapy (RT) and hypofractionated inverse planned stereotactic radiation therapy (SRT) for locally advanced or recurrent adenoid cystic carcinomas (ACCs) of the head and neck. Patients and methods. Five patients with ACCs of the head and neck were treated with combined conventional RT and inverse planned SRT. Radiation doses of 40 to 50 Gy were delivered with 20 to 25 fractions using conventional RT, and then an additional 20 to 25 Gy was delivered by 4 to 5 fractions of SRT. Results. Median follow-up was 12 months. Local control was obtained in all 5 patients, PR in 2 patients and SD in 3 patients. According to the Radiation Therapy Oncology Group (RTOG) late-radiation morbidity scoring criteria, adverse effects included Grade 2 xerostomia in 1 patient, Grade 2 trismus in 1 patient, and Grade 4 mucosal ulceration in 1 patient. Conclusion. Combined treatment with conventional RT and hypofractionated inverse planned SRT may be effective for short-term local control in patients with locally advanced or recurrent ACCs. Further evaluation is needed for long-term follow-up., 目的放射線抵抗性である頭頚部領域の腺様.胞癌に対する通常分割照射＋サイバーナイフによるインバースプラン低分割定位照射追加の治療成績を検討する．対象と方法九州大学病院放射線科にて2006 年12 月から2007 年９月までに放射線治療を施行した頭頚部領域の腺様.胞癌５例を対象とした．平均年齢61.4 歳（53-73 歳），男性２例，女性３例，部位は上顎洞２例，中咽頭２例，耳下腺１例で，初発２例，再発３例であった．放射線治療通常分割照射を先行後，腫瘍遺残部にサイバーナイフによる低分割定位照射を追加した．通常分割照射線量は40-50Gy（20-25分割），低分割定位照射追加線量は20-25Gy（4-5分割）で，総線量はα/β=10としてBiological effective doseは78.0.97.5Gy（86.4± 6.3）であった．観察期間中央値は12ケ月（８.18 ケ月）であった．結果腫瘍縮小は全例にみられ，局所制御は100%であった（PR２例，SD３例）．１例で照射野外に再発を認め追加放射線治療が施行され，肺・肝転移の1 例は放射線治療後に全身化学療法が施行された．有害事象はRTOGGrade 2 の唾液分泌障害1例，Grade 2の顎関節症１例，Grade 4の粘膜潰瘍を認めた．考察放射線抵抗性腫瘍である腺様.胞癌に対する放射線治療は，通常分割照射のみでは局所制御が充分に得られない可能性があるが，本報告ではサイバーナイフによる低分割定位照射の併用により良好な局所一次効果が確認され，有害事象も許容できると考えられた．今後は長期の腫瘍制御および晩期有害事象の評価が必要と考えられた．

We report a case of radiation fibrosis appearing as mass-like consolidation, which was difficult to distinguish from local recurrence. A 72-year-old woman was diagnosed as having primary lung cancer (cT1N0M0 stage IA) in the right upper lobe and was treated with SBRT of 48 Gy in 4 fractions. After 12 months, mass-like consolidation appeared around the irradiated area, and after 13 months, it had increased in size. FDG-PET revealed high uptake (SUV max=5.61) for the consolidation. CT-guided biopsy was performed, but we could not confirm the diagnosis. Considering her poor respiratory function and her age, short-interval follow-up was performed. After 15 months, the consolidation enlarged at the dorsal side, and carcinoembryonic antigen (CEA) became elevated (14.6 ng/mL). Serum KL-6 (436 U/mL) and SP-D (204 ng/mL) were also elevated. However, after 16 months, serum CEA slightly decreased. The consolidation gradually retracted on follow-up CT images. CEA, KL-6, and SP-D were also decreased by degrees. After 40 months, there is no evidence of local recurrence.