BMC Cancer (Apr 2010)

Focal dose escalation using FDG-PET-guided intensity-modulated radiation therapy boost for postoperative local recurrent rectal cancer: a planning study with comparison of DVH and NTCP

  • Nemoto Kenji,
  • Ogawa Yoshihiro,
  • Umezawa Rei,
  • Fujimoto Keisuke,
  • Metoki Takahiro,
  • Narazaki Kakutaro,
  • Katja Lindel,
  • Takeda Ken,
  • Takai Yoshihiro,
  • Kaneta Tomohiro,
  • Ariga Hisanori,
  • Jingu Keiichi,
  • Koto Masashi,
  • Mitsuya Masatoshi,
  • Matsufuji Naruhiro,
  • Takahashi Shoki,
  • Yamada Shogo

DOI
https://doi.org/10.1186/1471-2407-10-127
Journal volume & issue
Vol. 10, no. 1
p. 127

Abstract

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Abstract Background To evaluate the safety of focal dose escalation to regions with standardized uptake value (SUV) >2.0 using intensity-modulated radiation therapy (IMRT) by comparison of radiotherapy plans using dose-volume histograms (DVHs) and normal tissue complication probability (NTCP) for postoperative local recurrent rectal cancer Methods First, we performed conventional radiotherapy with 40 Gy/20 fr. (CRT 40 Gy) for 12 patients with postoperative local recurrent rectal cancer, and then we performed FDG-PET/CT radiotherapy planning for those patients. We defined the regions with SUV > 2.0 as biological target volume (BTV) and made three boost plans for each patient: 1) CRT boost plan, 2) IMRT without dose-painting boost plan, and 3) IMRT with dose-painting boost plan. The total boost dose was 20 Gy. In IMRT with dose-painting boost plan, we increased the dose for BTV+5 mm by 30% of the prescribed dose. We added CRT boost plan to CRT 40 Gy (summed plan 1), IMRT without dose-painting boost plan to CRT 40 Gy (summed plan 2) and IMRT with dose-painting boost plan to CRT 40 Gy (summed plan 3), and we compared those plans using DVHs and NTCP. Results Dmean of PTV-PET and that of PTV-CT were 26.5 Gy and 21.3 Gy, respectively. V50 of small bowel PRV in summed plan 1 was significantly higher than those in other plans ((summed plan 1 vs. summed plan 2 vs. summed plan 3: 47.11 ± 45.33 cm3 vs. 40.63 ± 39.13 cm3 vs. 41.25 ± 39.96 cm3(p 30, V40, V60, Dmean or NTCP of small bowel PRV. Conclusions FDG-PET-guided IMRT can facilitate focal dose-escalation to regions with SUV above 2.0 for postoperative local recurrent rectal cancer.