Stereotactic Ablative Radiotherapy for Reirradiation of Locally Recurrent Lung Tumors
JOURNAL OF THORACIC ONCOLOGY
2012; 7 (9): 1462-1465
Tumor Volume as a Potential Imaging-Based Risk-Stratification Factor in Trimodality Therapy for Locally Advanced Non-small Cell Lung Cancer
JOURNAL OF THORACIC ONCOLOGY
2011; 6 (5): 920-926
Patients with thoracic tumors that recur after irradiation currently have limited therapeutic options. Retreatment using stereotactic ablative radiotherapy (SABR) is appealing for these patients because of its high conformity but has not been studied extensively. Here we report our experience with SABR for lung tumors in previously irradiated regions.We conducted a retrospective study of patients with primary lung cancer or metastatic lung tumors treated with SABR. We identified 17 such tumors in 15 patients and compared their outcomes with those of a cohort of 135 previously unirradiated lung tumors treated with SABR during the same time period.Twelve-month local control (LC) for retreated tumors was 65.5%, compared with 92.1% for tumors receiving SABR as initial treatment. Twelve-month LC was significantly worse for reirradiated tumors in which the time interval between treatments was 16 months or less (46.7%), compared with those with longer intertreatment intervals (87.5%). SABR reirradiation did not lead to significant increases in treatment-related toxicity.SABR for locally recurrent lung tumors arising in previously irradiated fields seems to be feasible and safe for appropriately selected patients. LC of retreated lesions was significantly lower, likely owing to the lower doses used for retreatment. Shorter time to retreatment was associated with increased risk of local failure, suggesting that these tumors may be particularly radioresistant. Our findings suggest that dose escalation may improve LC while maintaining acceptable levels of toxicity for these patients.
View details for DOI 10.1097/JTO.0b013e31825f22ce
View details for Web of Science ID 000308073300024
View details for PubMedID 22895143
The role of trimodality therapy for locally advanced non-small cell lung cancer (NSCLC) continues to be defined. We hypothesized that imaging parameters on pre- and postradiation positron emission tomography (PET)-computed tomography (CT) imaging are prognostic for outcome after preoperative chemoradiotherapy (CRT)/resection/consolidation chemotherapy and could help risk-stratify patients in clinical trials.We enrolled 13 patients on a prospective clinical trial of trimodality therapy for resectable locally advanced NSCLC. PET-CT was acquired for radiation planning and after 45 Gy. Gross tumor volume (GTV) and standardized uptake value were measured at pre- and post-CRT time points and correlated with nodal pathologic complete response, loco-regional and/or distant progression, and overall survival. In addition, we evaluated the performance of automatic deformable image registration (ADIR) software for volumetric response assessment.All patients responded with average total GTV reductions after 45 Gy of 43% (range: 27-64%). Pre- and post-CRT GTVs were highly correlated (R² = 0.9), and their respective median values divided the patients into the same two groups. ADIR measurements agreed closely with manually segmented post-CRT GTVs. Patients with GTV ? median (137 ml pre-CRT and 67 ml post-CRT) had 3-year progression-free survival (PFS) of 14% versus 75% for GTV less than median, a significant difference (p = 0.049). Pre- and post-CRT PET-standardized uptake value did not correlate significantly with pathologic complete response, PFS, or overall survival.Preoperative CRT with carboplatin/docetaxel/45 Gy resulted in excellent response rates. In this exploratory analysis, pre- and post-CRT GTV predicted PFS in trimodality therapy, consistent with our earlier studies in a broader cohort of NSCLC. ADIR seems robust enough for volumetric response assessment in clinical trials.
View details for DOI 10.1097/JTO.0b013e31821517db
View details for Web of Science ID 000289554100012
View details for PubMedID 21774104