Phase I study of stereotactic body radiation therapy for peripheral T2N0M0 non-small cell lung cancer with PTV <100 cc using a continual reassessment method (JCOG0702)

Radiother Oncol. 2015 Aug;116(2):276-80. doi: 10.1016/j.radonc.2015.07.008. Epub 2015 Jul 29.


Purpose: To estimate the maximum tolerated dose (MTD) and to determine the recommended dose (RD) of stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinoma (NSCLC) with target volume (PTV) < 100 cc.

Materials and methods: The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the MTD. Dose limiting toxicity (DLT) was grade 3 radiation pneumonitis (RP) within 180 days after the start of SBRT, grade 2 RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D95 of the PTV.

Results: Fifteen patients were accrued. Only 1 experienced grade 2 RP at 60 Gy in 4 fractions. It was difficult to fulfill the dose constraints at 60 Gy in 4 fractions, and the maximum dose level assigned by CRM was changed to 55 Gy in 4 fractions. The lower limit of 95% of the credible interval exceeded the adjacent level, and the RD was determined as 55 Gy in 4 fractions.

Conclusions: The RD of SBRT for peripheral T2N0M0 NSCLC with PTV<100 cc was determined to be 55 Gy in 4 fractions.

Keywords: Continual reassessment method; Non-small cell lung cancer (NSCLC); Phase I study; SBRT; Stereotactic body radiotherapy.

Publication types

  • Clinical Trial, Phase I
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / surgery*
  • Female
  • Humans
  • Lung Neoplasms / pathology
  • Lung Neoplasms / surgery*
  • Male
  • Maximum Tolerated Dose
  • Neoplasm Staging
  • Radiosurgery* / adverse effects
  • Radiotherapy Dosage