gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Radiation-induced Cancers from Modern Radiotherapy Techniques: 3D CRT vs. Tomotherapy vs. Proton Therapy

Meeting Abstract

  • M. Yoon - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • D. H. Shin - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • J. S. Kim - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • J. W. Kim - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • D. W. Kim - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • S. B. Lee - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea
  • S. Y. Park - Proton Therapy Center, National Cancer Center, Goyang, Korea, Republic of Korea

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog229

DOI: 10.3205/09ptcog229, URN: urn:nbn:de:0183-09ptcog2297

Published: September 24, 2009

© 2009 Yoon et al.
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Outline

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Background: The secondary cancer risk originated from radiation treatment is an important issue for pediatric cancer patients. The probability of cancer is linearly related to absorbed dose, up to about 2.5 Sv, but is no longer linear at higher doses. Relative cancer risk may decrease at high radiation doses, due to cell killing or a plateau effect. This has led to the concept of organ equivalent dose (OED) to estimate the secondary cancer risks of individuals treated with various radiotherapy modalities. In this study, we have assessed and compared secondary cancer risk resulting from 3D-CRT, tomotherapy and proton therapy in patients with medulloblastoma using the concept of OED for radiation-induced cancer.

Methods and materials: Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and proton beam treatment (PBT) in the scattering mode were planned for 10 patients each, who are treated by craniospinal irradiation (CSI) at our institution. Dosimetric benefits and organ specific radiation-induced cancer risk were obtained based on the comparison of the dose volume histogram (DVH) and by applying organ equivalent dose (OED), respectively.

Results: In the analysis of the organ at risk volume that was delivered 30%, 60%, 90% of the prescribed dose (PD), PBT was superior to TOMO and 3D-CRT. The average dose of esophagus, stomach, liver, lung, pancreas and kidney in PBT were 19.4%, 0.6%, 0.3%, 2.5%, 0.2% and 2.2% of the PD, respectively which is significantly lower compared to TOMO (22.9%, 4.5%, 6.1%, 4.0%, 13.3%. 4.9%) and 3D-CRT (34.6%, 3.6%, 8.0%, 4.6%,22.9%,4.3%). Although the average doses of PBT were significantly lower than those of 3D-CRT or TOMO for chest and abdominal lesions, these differences were reduced for head & neck lesions. OED calculations showed that the risk of secondary cancers in various organs such as the stomach, lungs and thyroid, pancreas, etc was much higher for 3D-CRT or TOMO than for PBT.

Conclusions: Comparisons of organ specific OED showed that the estimated secondary cancer risk in the treatment of medulloblastoma patient is significantly lower in proton therapy than the cases in 3D-CRT or tomotherapy treatment.