Proceedings of the 53rd Annual ASTRO Meeting
S319
Table. Parameters
RA (mean+/-standard deviation)
3DCRT (mean+/-standard deviation)
Percent Benefit
P value (2 tailed)
V5 V10 V15 V20 V40 MLD HV30 MHD CMD
69.7+/-10.1% 45+/-11.1% 32+/-7% 22+/-5.2% 5.8+/-0.9% 13.8+/-2.3 Gy 46.8+/-18.1% 24.3+/-6.2 Gy 44+/-0.7 Gy
68+/-7.3% 48.8+/-8.1% 40.2+/-8.3% 29.7+/-7.3% 15.9+/-2.7% 17.1+/-2.2 Gy 55.2+/-16.6% 28.1+/-6.9 Gy 46.9+/-1.5 Gy
-2 8 20 26 63 19 15 13 6
0.16 0.15 0.003 0.003 0.000 0.003 0.002 0.003 0.002
Author Disclosure: S. Chilukuri: None. Y. Pawar: None. V. Subramanian: None. M. Kathirvel: None. I. Mallick: None. G. Arun: None. S. Thirumalai Swamy: None. N. JagadheesKumar: None. Y. Nallini: None. M. Babaiah: None.
2223
Long-term Results of Chemoradiotherapy for Solitary Lymph Node Metastasis after Curative Resection of Esophageal Cancer
K. Jingu1, H. Ariga1, K. Nemoto2, R. Umezawa1, K. Takeda1, S. Yamada1 1 Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Japan, 2Department of Radiation Oncology, Yamagata University School of Medicine, Yamagata, Japan
Purpose/Objective(s): To evaluate the long-term efficacy and toxicity of definitive chemoradiotherapy for solitary lymph node metastasis after curative surgery of esophageal cancer. Materials/Methods: We performed a retrospective review of 35 patients who underwent definitive chemoradiotherapy at Tohoku University Hospital between 2000 and 2009 for solitary lymph node metastasis after curative esophagectomy with lymph node dissection for esophageal cancer. Radiotherapy doses ranged from 60 to 66 Gy (median, 60 Gy). Concurrent chemotherapy was platinum-based in all patients. The endpoints of the present study were overall survival rate, cause-specific survival rate, progression-free survival rate, irradiated-field control rate, overall tumor response rate and prognostic factors. Results: The median observation period for survivors was 70.0 months. The 5-year overall survival rate was 39.2% with a median survival period of 39.0 months. The 5-year cause-specific survival rate, progression-free survival rate and irradiated-field control rate were 43.3%, 31.0% and 59.9%, respectively. Metastatic lesion, size of the metastatic lymph node and performance status before chemoradiotherapy were significantly correlated with prognosis. Complete response and partial response were observed in 22.9% and 57.1% of the patients, respectively. There was no grade 3 or higher adverse effect (CTCAE v3.0) in the late phase. Conclusions: About 40% of patients with solitary lymph node metastasis after curative resection for esophageal cancer have a chance of long-term survival with definitive chemoradiotherapy. Author Disclosure: K. Jingu: None. H. Ariga: None. K. Nemoto: None. R. Umezawa: None. K. Takeda: None. S. Yamada: None.
2224
Measuring Tumor Hypoxia with 18F-FETNIM PET in Esophageal Squamous Cell Carcinoma: A Pilot Clinical Study
J. Yue1, J. Yu1, A. R. Cabrera2, X. Sun1, S. Zhao1, L. Ma1 1
Shandong Cancer Hospital and Institute, Jinan, China, 2Duke University Medical Center, Durham, NC
Purpose/Objective(s): To evaluate hypoxia in esophageal squamous cell carcinoma (SCC) with (18F-FETNIM PET/CT. We determined an imaging threshold for hypoxia, quantified the spatiotemporal variability of hypoxia in untreated tumor, and evaluated the ability of 18F-FETNIM PET to predict clinical response following concurrent chemoradiotherapy (CCRT). Materials/Methods: Twenty-eight consecutive patients with inoperable SCC of the esophagus were consecutively accrued between April 2007 and June 2010. The first 10 patients received two pretreatment 18F-FETNIM-PET/CT scans on separate days. The remaining 18 patients only underwent 18F-FETNIM-PET/CT once before CCRT. The ratio of the maximum standardized uptake value (SUVmax) of 336 normal tissue regions (i.e., heart, lung, brain or muscle) to the mean standardized uptake value (SUVmean) of the respective patient’s spleen was calculated, and the imaging threshold for hypoxia defined as the level of uptake demonstrated by less than 5% of tissue regions. Among the patients with two pretreatment scans, each pair of scans was compared with respect to location and intensity of uptake to assess for baseline spatiotemporal variability. Logistic regression analysis was used to determine whether pretreatment imaging characteristics are predictive of clinical response. Results: The mean and median ratios of the SUVmax of tissue:SUVmean of spleen were nearly identical, and 95% of the ratios fell below 1.3. The mean Dice similarity coefficient for the hypoxic volumes on pretreatment PET scans acquired in the same patient on different days was 0.12 (range, 0.05-0.21). Individuals’ tumor SUVmax and SUVmean did not vary significantly, but on average, the geometric centers of hypoxic regions shifted 15 mm (range, 8-20 mm) from the first pretreatment scan to the second. SUVmax was the imaging characteristic most predictive of treatment response (p = 0.041), with high SUVmax associated with poor clinical response. Conclusions: 18F-FETNIM PET/CT scan depict hypoxia in esophageal SCC. Prior to CCRT, tumor hypoxia demonstrates spatial variability on different days, though overall 18F-FETNIM uptake remains similar. Baseline SUVmax may be predictive of treatment response. Author Disclosure: J. Yue: None. J. Yu: None. A.R. Cabrera: None. X. Sun: None. S. Zhao: None. L. Ma: None.