Chung Christine, Trofimov Alexei, Adams Judith, Kung Jong, Kirsch David G, Yoon Sam, Doppke Karen, Bortfeld Thomas, Delaney Thomas F
John Muir Health, Department of Radiation Oncology, 400 Taylor Boulevard Suite 101, Pleasant Hill, CA 94523, USA.
Massachusetts General Hospital, Mass General Department of Radiation Oncology, 30 Fruit Street, Boston, MA 02114, USA.
Sarcoma. 2022 Mar 19;2022:5540615. doi: 10.1155/2022/5540615. eCollection 2022.
External beam radiation therapy (RT) for retroperitoneal sarcoma often requires treatment of large target volumes close to critical normal tissues. Radiation may be limited by adjacent organs at risk (OAR). Intensity-modulated radiation therapy has been shown to improve target coverage and reduce doses to OAR.
To compare target coverage and dose to OAR with 3D conformal proton therapy (3D CPT), intensity-modulated proton therapy (IMPT), and intensity-modulated photon therapy (IMXT).
We performed a comparative study of treatment plans with 3D CPT, IMPT, and IMXT for ten patients with retroperitoneal sarcomas. RT was delivered to 50.4 Gy to the clinical target volume (CTV), the structures considered at risk for microscopic disease.
CTVs ranged from 74 to 357 cc (mean 188 cc). Dose conformity was improved with IMPT, while 3D CPT provided better dose homogeneity. Mean dose to the liver, small bowel, and stomach was reduced with IMPT compared with 3D CPT or IMXT.
IMPT, 3D CPT, and IMXT provide excellent target coverage for retroperitoneal sarcomas. OAR dose is lower with IMPT and 3D CPT, and IMPT achieves the closest conformity. These techniques offer the opportunity for further dose escalation to areas with positive margins.
腹膜后肉瘤的外照射放疗（RT）通常需要对靠近关键正常组织的大靶区进行治疗。放疗可能会受到相邻危及器官（OAR）的限制。调强放射治疗已被证明可改善靶区覆盖并降低对OAR的剂量。
比较三维适形质子治疗（3D CPT）、调强质子治疗（IMPT）和调强光子治疗（IMXT）对靶区的覆盖情况及对OAR的剂量。
我们对10例腹膜后肉瘤患者采用3D CPT、IMPT和IMXT进行治疗计划的比较研究。对临床靶区（CTV）给予50.4 Gy的放疗，CTV是考虑存在微小病灶风险的结构。
CTV范围为74至357 cc（平均188 cc）。IMPT改善了剂量适形性，而3D CPT提供了更好的剂量均匀性。与3D CPT或IMXT相比，IMPT降低了肝脏、小肠和胃的平均剂量。
IMPT、3D CPT和IMXT为腹膜后肉瘤提供了良好的靶区覆盖。IMPT和3D CPT的OAR剂量较低，且IMPT实现了最接近的适形性。这些技术为进一步提高切缘阳性区域的剂量提供了机会。
