Early [18F]fluorodeoxyglucose positron emission tomography at two days of gefitinib treatment predicts clinical outcome in patients with adenocarcinoma of the lung

Clin Cancer Res. 2012 Jan 1;18(1):220-8. doi: 10.1158/1078-0432.CCR-11-0868. Epub 2011 Oct 21.

Abstract

Purpose: Positron emission tomography (PET) with [(18)F]fluorodeoxyglucose (FDG) is increasingly used in early assessment of tumor response after chemotherapy. We investigated whether a change in [(18)F]FDG uptake at 2 days of gefitinib treatment predicts outcome in patients with lung adenocarcinoma.

Experimental design: Twenty patients were enrolled. [(18)F]FDG-PET/computed tomographic (CT) scan was carried out before and 2 days after gefitinib treatment. Maximum standardized uptake values (SUV) were measured, and post-gefitinib percentage changes in SUV were calculated. Early metabolic response (SUV decline < -25%) was compared with morphologic response evaluated by CT scan and with progression-free survival (PFS).

Results: At 2 days of gefitinib treatment, 10 patients (50%) showed metabolic response, 8 had metabolic stable disease, and 2 had progressive metabolic disease. Percentage changes of SUV at 2 days were correlated with those of tumor size in CT at 1 month (R(2) = 0.496; P = 0.0008). EGFR gene was assessable in 15 patients, and of 12 patients with EGFR mutations, 8 showed metabolic response at 2 days and 6 showed morphologic response at 1 month. None of 3 patients with wild-type EGFR showed metabolic or morphologic response. Metabolic response at 2 days was not statistically associated with PFS (P = 0.095), but when a cutoff value of -20% in SUV decline was used, metabolic responders had longer PFS (P < 0.0001).

Conclusion: Early assessment of [(18)F]FDG tumor uptake with PET at 2 days of gefitinib treatment could be useful to predict clinical outcome earlier than conventional CT evaluation in patients with lung adenocarcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma / drug therapy
  • Adenocarcinoma / mortality
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / therapeutic use
  • Carcinoma, Adenosquamous / diagnostic imaging*
  • Carcinoma, Adenosquamous / drug therapy
  • Carcinoma, Adenosquamous / mortality
  • ErbB Receptors / genetics
  • Female
  • Fluorodeoxyglucose F18*
  • Gefitinib
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / mortality
  • Male
  • Middle Aged
  • Multimodal Imaging*
  • Mutation / genetics
  • Positron-Emission Tomography*
  • Prognosis
  • Quinazolines / therapeutic use*
  • Radiopharmaceuticals
  • Survival Rate
  • Tomography, X-Ray Computed*

Substances

  • Antineoplastic Agents
  • Quinazolines
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • EGFR protein, human
  • ErbB Receptors
  • Gefitinib