Article

Positron Emission Tomography for Assessing Local Failure After Stereotactic Body Radiotherapy for Non-Small-Cell Lung Cancer

Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
International journal of radiation oncology, biology, physics (Impact Factor: 4.18). 05/2012; 83(5):1558-65. DOI: 10.1016/j.ijrobp.2011.10.035
Source: PubMed

ABSTRACT We analyzed whether positron emission tomography (PET)/computed tomography standardized uptake values (SUVs) after stereotactic body radiotherapy (SBRT) could predict local recurrence (LR) in non-small-cell lung cancer (NSCLC).
This study comprised 128 patients with Stage I (n = 68) or isolated recurrent/secondary parenchymal (n = 60) NSCLC treated with image-guided SBRT to 50 Gy over 4 consecutive days; prior radiotherapy was allowed. PET/computed tomography scans were obtained before therapy and at 1 to 6 months after therapy, as well as subsequently as clinically indicated. Continuous variables were analyzed with Kruskal-Wallis tests and categorical variables with Pearson chi-square or Fisher exact tests. Actuarial local failure rates were calculated with the Kaplan-Meier method.
At a median follow-up of 31 months (range, 6-71 months), the actuarial 1-, 2-, and 3-year local control rates were 100%, 98.5%, and 98.5%, respectively, in the Stage I group and 95.8%, 87.6%, and 85.8%, respectively, in the recurrent group. The cumulative rates of regional nodal recurrence and distant metastasis were 8.8% (6 of 68) and 14.7% (10 of 68), respectively, for the Stage I group and 11.7% (7 of 60) and 16.7% (10 of 60), respectively, for the recurrent group. Univariate analysis showed that SUVs obtained 12.1 to 24 months after treatment for the Stage I group (p = 0.007) and 6.1 to 12 months and 12.1 to 24 months after treatment for the recurrent group were associated with LR (p < 0.001 for both). Of the 128 patients, 17 (13.3%) had ipsilateral consolidation after SBRT but no elevated metabolic activity on PET; none had LR. The cutoff maximum SUV of 5 was found to have 100% sensitivity, 91% specificity, a 50% positive predictive value, and a 100% negative predictive value for predicting LR.
PET was helpful for distinguishing SBRT-induced consolidation from LR. SUVs obtained more than 6 months after SBRT for NSCLC were associated with local failure. A maximum SUV greater than 5, especially at more than 6 months after SBRT, should prompt biopsy to rule out LR.

Full-text

Available from: Hui Liu, Apr 04, 2014
0 Followers
 · 
128 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Stereotactic radiotherapy for lung cancer is a technique that is now well established in the therapeutic arsenal. Protocols are effective, with very high local control rate and an acceptable rate of survival if one takes into account the patient's age and comorbidities. Complications are rare. This review of the literature analyses the whole process of the therapeutic indications and future prospects.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and purpose We report our outcomes for patients with NSCLC treated with SABR to 70 Gy in 10 fractions and propose indications for this regimen as well as new dose–volume constraints. Materials and methods Volumetric image-guided SABR was used to treat 82 patients with clinical challenging NSCLC, not suitable for 50 Gy in 4 fractions, to a final dose of 70 Gy in 10 fractions. Endpoints included overall survival (OS), toxicity, and disease control. Results At a median follow-up time of 21.1 months, 2-year OS and local control rates were 66.9% and 96.2%, respectively. The most common side effects were radiation pneumonitis (14.6% grade 2, 2.4% grade 3), followed by chest wall pain (4.9% grade 2, 1.2% grade 3). Multivariate analysis revealed chest wall V50 > 60 cm3 to be associated with chest wall pain. No patient developed brachial plexopathy. One patient with bronchial tree tumor invasion died of hemoptysis. Conclusions SABR with 70 Gy in 10 fractions appears to achieve excellent local control and acceptable toxicity for clinically challenging cases with improved tolerance of the chest wall and brachial plexus as compared with 50 Gy in 4 fractions. This regimen may not be suitable in patients with tumor invading critical central structures. More studies are needed to validate our conclusions.
    Radiotherapy and Oncology 08/2014; 112(2). DOI:10.1016/j.radonc.2014.07.010 · 4.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Stereotactic body radiotherapy is the treatment of choice for medically non-operable T1-T2 N0M0 non-small cell lung cancer or for slowly growing lung metastases with no evolutive primary tumour. Lung stereotactic radiotherapy provides an excellent local control rate, higher than 80%. Nevertheless, although the clinical toxicity rate is less than 5%, postradiation radiological reactions surrounding the tumour, called “radiological radiation pneumonitis”, are very frequent, which makes it difficult to evaluate the tumour response. Firstly, this review describes the lesions of acute and chronic radiation pneumonitis and the CT images suggesting a local recurrence. Then, we evaluated the place of PET after stereotactic body radiotherapy in the follow-up period. Finally, we suggest an algorithm helping physicians in the follow-up of such treated patients.
    Cancer/Radiothérapie 10/2014; DOI:10.1016/j.canrad.2014.07.157 · 1.11 Impact Factor