Whole-tumour CT-perfusion of unresectable lung cancer for the monitoring of anti-angiogenetic chemotherapy effects.

OBJECTIVE

To determine whether CT-perfusion (CT-p) can be used to evaluate the effects of chemotherapy and anti-angiogenic treatment in patients with non-small-cell lung carcinoma (NSCLC) and whether CT-p and standard therapeutic response assessment (RECIST) data obtained before and after therapy correlate.

METHODS

55 patients with unresectable NSCLC underwent CT-p before the beginning of therapy and 50 of them repeated CT-p 90 days after it. Therapeutic protocol included platinum-based doublets plus bevacizumab for non-squamous carcinoma and platinum-based doublets for squamous carcinoma. RECIST measurements and calculations of blood flow (BF), blood volume (BV), time to peak (TTP) and permeability surface (PS) were performed, and baseline and post-treatment measurements were tested for statistically significant differences. Baseline and follow-up perfusion parameters were also compared based on histopathological subclassification (2004 World Health Organization Classification of Tumours) and therapy response assessed by RECIST.

RESULTS

Tumour histology was consistent with large cell carcinoma in 14/50 (28%) cases, adenocarcinoma in 22/50 (44%) cases and squamous cell carcinoma in the remaining 14/50 (28%) cases. BF and PS differences for all tumours between baseline and post-therapy measurements were significant (p=0.001); no significant changes were found for BV (p=0.3) and TTP (p=0.1). The highest increase of BV was demonstrated in adenocarcinoma (5.2±34.1%), whereas the highest increase of TTP was shown in large cell carcinoma (6.9±22.4%), and the highest decrease of PS was shown in squamous cell carcinoma (-21.5±18.5%). A significant difference between the three histological subtypes was demonstrated only for BV (p<0.007). On the basis of RECIST criteria, 8 (16%) patients were classified as partial response (PR), 2 (4%) as progressive disease (PD) and the remaining 40 (80%) as stable disease (SD). Among PR, a decrease of both BF (18±9.6%) and BV (12.6±9.2%) were observed; TTP increased in 3 (37.5%) cases, and PS decreased in 6 (75%) cases. SD patients showed an increase of BF, BV, TTP and PS in 6 (15%), 21 (52.5%), 23 (57.5%) and 2 (5%) cases, respectively. PD patients demonstrated an increase of BF (26±0.2%), BV (2.7±0.1%) and TTP (3.1±0.8%) while only PS decreased (23±0.2%).

CONCLUSION

CT-p can adequately evaluate therapy-induced alterations in NSCLC, and perfusion parameters correlate with therapy response assessment performed with RECIST criteria.

ADVANCES IN KNOWLEDGE

Evaluating perfusional parameters, CT-p can demonstrate therapy-induced changes in patients with different types of lung cancer and identify response to treatment with excellent agreement to RECIST measurements.