内容紹介
Concurrent Proton Therapy and Chemotherapy for Locally Advanced Cancers
Summary
Charged particles such as protons and carbon-ions offer advantageous physical properties to radiation therapy(RT)for the treatment of various cancers when compared with photons, because they exhibit a spread-out Bragg peak, and may be utilized to achieve a desirable dose distribution to the target volume by using specified beam modulation. Interestingly, the cytocidal effect of protons is almost equal to that of photons, because both protons and photons are considered low-linear energy transfer radiations. Hence, proton beam therapy(PBT)is an attractive RT option, especially in the treatment of locally advanced cancers, as irradiation doses can be safely escalated while sparing the surrounding normal tissues, and because PBT may be concurrently combined with chemotherapy for treating such cancers. Recent advances in PBT techniques including a spot scanning method, as well as an increase in the number of particle therapy institutes are anticipated to yield favorable results through future multi-institutional prospective studies.
The University of Tsukuba has carried out several studies to validate the effectiveness of PBT for many types of cancers since 1983. Here, we present our findings on the clinical outcomes of PBT for esophageal cancer, non-small cell lung cancer, intrahepatic biliary tract cancer, pancreas cancer, and bladder cancer; future aspects of PBT concurrently combined with chemotherapy for treating locally advanced cancers are also discussed.
要旨
陽子線は炭素イオン線と同等に物理学的特徴として荷電された粒子が止まり,その直前で深部相対線量が最大となるため,X線と比較し線量分布が良好である。一方,陽子線の単位長さ当たりに付与するエネルギーはX線と同様に低いため,その生物学的効果はX線とほぼ同等である。それゆえ,陽子線治療は進行癌に対して局所制御を改善する目的とした線量の増加を図れるとともに,化学療法を安全に併用できる魅力的な治療である。国内での施設数の増加とともに,スポットスキャン法をはじめとした新しい治療技術開発も進んでおり,他施設共同研究も現在模索されている。本稿では同時化学放射線療法を行う進行癌として,食道癌,非小細胞肺癌,肝内胆管癌,膵癌および膀胱癌について,筑波大学で1983年から取り組んできた陽子線治療成績について文献的考察を交えて紹介するとともに,今後の展望を述べる。
目次
Summary
Charged particles such as protons and carbon-ions offer advantageous physical properties to radiation therapy(RT)for the treatment of various cancers when compared with photons, because they exhibit a spread-out Bragg peak, and may be utilized to achieve a desirable dose distribution to the target volume by using specified beam modulation. Interestingly, the cytocidal effect of protons is almost equal to that of photons, because both protons and photons are considered low-linear energy transfer radiations. Hence, proton beam therapy(PBT)is an attractive RT option, especially in the treatment of locally advanced cancers, as irradiation doses can be safely escalated while sparing the surrounding normal tissues, and because PBT may be concurrently combined with chemotherapy for treating such cancers. Recent advances in PBT techniques including a spot scanning method, as well as an increase in the number of particle therapy institutes are anticipated to yield favorable results through future multi-institutional prospective studies.
The University of Tsukuba has carried out several studies to validate the effectiveness of PBT for many types of cancers since 1983. Here, we present our findings on the clinical outcomes of PBT for esophageal cancer, non-small cell lung cancer, intrahepatic biliary tract cancer, pancreas cancer, and bladder cancer; future aspects of PBT concurrently combined with chemotherapy for treating locally advanced cancers are also discussed.
要旨
陽子線は炭素イオン線と同等に物理学的特徴として荷電された粒子が止まり,その直前で深部相対線量が最大となるため,X線と比較し線量分布が良好である。一方,陽子線の単位長さ当たりに付与するエネルギーはX線と同様に低いため,その生物学的効果はX線とほぼ同等である。それゆえ,陽子線治療は進行癌に対して局所制御を改善する目的とした線量の増加を図れるとともに,化学療法を安全に併用できる魅力的な治療である。国内での施設数の増加とともに,スポットスキャン法をはじめとした新しい治療技術開発も進んでおり,他施設共同研究も現在模索されている。本稿では同時化学放射線療法を行う進行癌として,食道癌,非小細胞肺癌,肝内胆管癌,膵癌および膀胱癌について,筑波大学で1983年から取り組んできた陽子線治療成績について文献的考察を交えて紹介するとともに,今後の展望を述べる。