舌・口腔底癌に対する高線量率分割組織内照射における治療容積の検討  [in Japanese] Dose-volume effect of high dose rate interstital rediation for tongue and mouth floor cancer.  [in Japanese]

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Abstract

高線量率組織内放射で治療した30例の舌癌患者と6例の口腔底癌の患者の Dose volume histogram をPLATOを用いて計算した。全例1回6Gyで治療した。20例の舌癌と6例の口腔底癌の患者は組織内単独で60Gy/10回の治療が行われた。他の12例は20~41Gyの外部照射と42~60Gyの組織内照射が行われた。V100%は1回6Gyの治療領域の容積とした。<br>舌癌患者では一面刺入, 一平面とチューブ1本追加, 二平面刺入および立体刺入の平均V100%はそれぞれ14cm<sup>3</sup>, 29cm<sup>3</sup>, 18cm<sup>3</sup>および64cm<sup>3</sup>であり, V200%は3cm<sup>3</sup>, 8cm<sup>3</sup>, 3cm<sup>3</sup>および10cm<sup>3</sup>であった。口腔底癌のV100%とV200%は10cm<sup>3</sup>と3cm<sup>3</sup>であった。<br>組織内単独治療例では2例の再発は治療容積の小さな症例 (V100%: 9.7cm<sup>3</sup>, 11.0cm<sup>3</sup>) で認められた。また潰瘍は容積の大きな症例 (V100%: 25.6cm<sup>3</sup>, 31.8cm<sup>3</sup>) に出現した。口腔底癌患者の治療容積は舌癌患者と比べて小さい。今回の6例については潰瘍を認めなかった。<br>外部照射と高線量率組織内照射の併用を行った舌癌10例では6例が一平面刺入で治療され, 4例が立体刺入であった。一平面刺入ではV100%とV200%は13~19cm<sup>3</sup>と2.3~4.3cm<sup>3</sup>であった。この6例では再発および潰瘍を認めていない。立体刺入ではV100%もV200%も共に他の刺入方法と比べて非常に大きい。再発のない症例では潰瘍が出現した。このような大きな腫瘍の症例では副作用なく治療することは難しい。<br>治療容積は局所制御および副作用の重要な因子である。

Dose volume histograms of the high dose rate brachytherapy for 30 patients with tongue cancer and 6 patients with cancer of the mouth floor were calculated by means of PLATO. All patients were treated with HDR brachytherapy of 6Gy per day. 20 patients with tongue cancer and 4 patients with mouthe floor cancer were treated with 60Gy/10 fractions of HDR brachytherapy alone. Other 12 patients were treated with 20-41Gy of external radiation and 42-60Gy of HDR brachytherapy. V100% was defined as the volume of 6Gy per fraction.<br>For tongue cancer, V100% of patients treated with single plane, single plane plus one tube, double plane and volume implant were 14cm<sup>3</sup>, 29cm<sup>3</sup>, 18cm<sup>3</sup> and 64cm<sup>3</sup>, respectively. The corresponding figures of V200% were 3cm<sup>3</sup>, 8cm<sup>3</sup>, 3cm<sup>3</sup> and 10cm<sup>3</sup>. V100% and V200% of mouth floor cancer were 10cm<sup>3</sup> and 3cm<sup>3</sup>.<br>For patients treated with HDR brachytherapy alone, local recurrence occurred in 2 patients with small treatment volume (V100%: 9.7cm<sup>3</sup>, 11.0cm<sup>3</sup>) and soft tissue ulcer occurred in 2 patients with large treatment volume (V100%: 25.6cm<sup>3</sup>, 31.8cm<sup>3</sup>). Treatment volumes of mouth floor cancer were small compared with tongue cancer patients. There were no soft tissue ulcer in 6 patients.<br>For 10 tongue cancer patients treated with combination of external radiation and HDR brachytherapy, 6 patients were treated with single plane implant and 4 patients with volume implant. For single plane implant, V100% and V200% were 13-19cm<sup>3</sup> and 2.3-4.3cm<sup>3</sup>, respectively. There were no local recurrence and no soft tissue ulcer. For volume implant, V100% and V200% were extremely high compared with other treatment. Ulcer occurred in the patient without local recurrence. It is difficult to treat these bulky tumor without late complication.<br>Treatment volume is an important factor for both local control and late complication.

Journal

  • Japanese jornal of Head and Neck Cancer

    Japanese jornal of Head and Neck Cancer 23(1), 19-23, 1997

    Japan Society for Head and Neck Cancer

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