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Title: Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer

Abstract

Purpose: To compare the planning target volume (PTV) definitions for computed tomography (CT) vs. positron emission tomography (PET) in non-small-cell lung cancer (NSCLC). Methods and Materials: A total of 21 patients with NSCLC underwent three-dimensional conformal radiotherapy planning. All underwent a staging F-18 fluorodeoxyglucose-position emission tomography ({sup 18}FDG-PET) scan and underwent treatment simulation using CT plus a separate planning {sup 18}FDG-PET scan. Three sets of target volumes were defined: Set 1, CT volumes (CT tumor + staging PET nodal disease); Set 2, PET volumes (planning PET tumor {l_brace}gross tumor volume (GTV) = [(0.3069 x mean standardized uptake value) + 0.5853]){r_brace}; Set 3, composite CT-PET volumes (fused CT-PET tumor). Sets 1 and 2 were compared using a matching index. Three-dimensional conformal radiotherapy plans were created using the Set 1 (CT) volumes; and coverage of the Set 3 (composite) volumes was evaluated. Separate three-dimensional conformal radiotherapy plans were designed for the Set 3 volumes. Results: For the primary tumor GTV, the Set 1 (CT) volume was larger than the Set 2 (PET) volume in 48%, smaller in 33%, and equal in 19%. The mean matching index was 0.65 (35% CT-PET mismatch). Although quantitatively similar, the volumes differed qualitatively. The Set 3 (composite)more » volume was larger than either CT or PET alone in 62%, smaller in 24%, and equal in 14%. The dose-volume histogram parameters did not differ among the plans for Set 1 (CT) vs. Set 3 (composite) volumes. Small portions of the Set 3 PTV were significantly underdosed in 40% of cases using the CT-only plan. Conclusion: Computed tomography and PET are complementary and should be obtained in the treatment position and fused to define the GTV for NSCLC. Although the quantitative absolute target volume is sometimes similar, the qualitative target locations can be substantially different, leading to underdosage of the target when planning is done using CT alone without PET fusion.« less

Authors:
 [1];  [2];  [2];  [2];  [2];  [2]
  1. Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States). E-mail: igrills@beaumont.edu
  2. Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States)
Publication Date:
OSTI Identifier:
20944720
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 67; Journal Issue: 3; Other Information: DOI: 10.1016/j.ijrobp.2006.09.046; PII: S0360-3016(06)03240-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; FLUORINE 18; FLUORODEOXYGLUCOSE; LUNGS; NEOPLASMS; PATIENTS; PLANNING; POSITRON COMPUTED TOMOGRAPHY; RADIATION DOSES; RADIOTHERAPY; UPTAKE

Citation Formats

Grills, Inga S., Yan Di, Black, Quinten C., Wong, Ching-Yee O., Martinez, Alvaro A., and Kestin, Larry L.. Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer. United States: N. p., 2007. Web. doi:10.1016/j.ijrobp.2006.09.046.
Grills, Inga S., Yan Di, Black, Quinten C., Wong, Ching-Yee O., Martinez, Alvaro A., & Kestin, Larry L.. Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer. United States. doi:10.1016/j.ijrobp.2006.09.046.
Grills, Inga S., Yan Di, Black, Quinten C., Wong, Ching-Yee O., Martinez, Alvaro A., and Kestin, Larry L.. Thu . "Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer". United States. doi:10.1016/j.ijrobp.2006.09.046.
@article{osti_20944720,
title = {Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer},
author = {Grills, Inga S. and Yan Di and Black, Quinten C. and Wong, Ching-Yee O. and Martinez, Alvaro A. and Kestin, Larry L.},
abstractNote = {Purpose: To compare the planning target volume (PTV) definitions for computed tomography (CT) vs. positron emission tomography (PET) in non-small-cell lung cancer (NSCLC). Methods and Materials: A total of 21 patients with NSCLC underwent three-dimensional conformal radiotherapy planning. All underwent a staging F-18 fluorodeoxyglucose-position emission tomography ({sup 18}FDG-PET) scan and underwent treatment simulation using CT plus a separate planning {sup 18}FDG-PET scan. Three sets of target volumes were defined: Set 1, CT volumes (CT tumor + staging PET nodal disease); Set 2, PET volumes (planning PET tumor {l_brace}gross tumor volume (GTV) = [(0.3069 x mean standardized uptake value) + 0.5853]){r_brace}; Set 3, composite CT-PET volumes (fused CT-PET tumor). Sets 1 and 2 were compared using a matching index. Three-dimensional conformal radiotherapy plans were created using the Set 1 (CT) volumes; and coverage of the Set 3 (composite) volumes was evaluated. Separate three-dimensional conformal radiotherapy plans were designed for the Set 3 volumes. Results: For the primary tumor GTV, the Set 1 (CT) volume was larger than the Set 2 (PET) volume in 48%, smaller in 33%, and equal in 19%. The mean matching index was 0.65 (35% CT-PET mismatch). Although quantitatively similar, the volumes differed qualitatively. The Set 3 (composite) volume was larger than either CT or PET alone in 62%, smaller in 24%, and equal in 14%. The dose-volume histogram parameters did not differ among the plans for Set 1 (CT) vs. Set 3 (composite) volumes. Small portions of the Set 3 PTV were significantly underdosed in 40% of cases using the CT-only plan. Conclusion: Computed tomography and PET are complementary and should be obtained in the treatment position and fused to define the GTV for NSCLC. Although the quantitative absolute target volume is sometimes similar, the qualitative target locations can be substantially different, leading to underdosage of the target when planning is done using CT alone without PET fusion.},
doi = {10.1016/j.ijrobp.2006.09.046},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 3,
volume = 67,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • Objective: To assess early tumor responsiveness and the corresponding effective radiosensitivity for individual patients with non-small cell lung cancer (NSCLC) based on 2 successive {sup 18}F-fludeoxyglucose positron emission tomography (FDG-PET) scans. Methods and Materials: Twenty-six NSCLC patients treated in Maastricht were included in the study. Fifteen patients underwent sequential chemoradiation therapy, and 11 patients received concomitant chemoradiation therapy. All patients were imaged with FDG before the start and during the second week of radiation therapy. The sequential images were analyzed in relation to the dose delivered until the second image. An operational quantity, effective radiosensitivity, α{sub eff}, was determined atmore » the voxel level. Correlations were sought between the average α{sub eff} or the fraction of negative α{sub eff} values and the overall survival at 2 years. Separate analyses were performed for the primary gross target volume (GTV), the lymph node GTV, and the clinical target volumes (CTVs). Results: Patients receiving sequential treatment could be divided into responders and nonresponders, using a threshold for the average α{sub eff} of 0.003 Gy{sup −1} in the primary GTV, with a sensitivity of 75% and a specificity of 100% (P<.0001). Choosing the fraction of negative α{sub eff} as a criterion, the threshold 0.3 also had a sensitivity of 75% and a specificity of 100% (P<.0001). Good prognostic potential was maintained for patients receiving concurrent chemotherapy. For lymph node GTV, the correlation had low statistical significance. A cross-validation analysis confirmed the potential of the method. Conclusions: Evaluation of the early response in NSCLC patients showed that it is feasible to determine a threshold value for effective radiosensitivity corresponding to good response. It also showed that a threshold value for the fraction of negative α{sub eff} could also be correlated with poor response. The proposed method, therefore, has potential to identify candidates for more aggressive strategies to increase the rate of local control and also avoid exposing to unnecessary aggressive therapies the majority of patients responding to standard treatment.« less
  • Purpose: {sup 18}F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has benefits in target volume (TV) definition in radiotherapy treatment planning (RTP) for non-small-cell lung cancer (NSCLC); however, an optimal protocol for TV delineation has not been determined. We investigate volumetric and positional variation in gross tumor volume (GTV) delineation using a planning PET/CT among three radiation oncologists and a PET radiologist. Methods and Materials: RTP PET/CT scans were performed on 28 NSCLC patients (Stage IA-IIIB) of which 14 patients received prior induction chemotherapy. Three radiation oncologists and one PET radiologist working with a fourth radiation oncologist independently delineated the GTV onmore » CT alone (GTV{sub CT}) and on fused PET/CT images (GTV{sub PETCT}). The mean percentage volume change (PVC) between GTV{sub CT} and GTV{sub PETCT} for the radiation oncologists and the PVC between GTV{sub CT} and GTV{sub PETCT} for the PET radiologist were compared using the Wilcoxon signed-rank test. Concordance index (CI) was used to assess both positional and volume change between GTV{sub CT} and GTV{sub PETCT} in a single measurement. Results: For all patients, a significant difference in PVC from GTV{sub CT} to GTV{sub PETCT} exists between the radiation oncologist (median, 5.9%), and the PET radiologist (median, -0.4%, p = 0.001). However, no significant difference in median concordance index (comparing GTV{sub CT} and GTV{sub FUSED} for individual cases) was observed (PET radiologist = 0.73; radiation oncologists = 0.66; p = 0.088). Conclusions: Percentage volume changes from GTV{sub CT} to GTV{sub PETCT} were lower for the PET radiologist than for the radiation oncologists, suggesting a lower impact of PET/CT in TV delineation for the PET radiologist than for the oncologists. Guidelines are needed to standardize the use of PET/CT for TV delineation in RTP.« less
  • Purpose: The aim of this study was to determine whether the preradiation maximum standardized uptake value (SUV{sub max}) of the primary tumor for [{sup 18}F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has a prognostic significance in patients with Stage T1 or T2N0 non-small cell lung cancer (NSCLC) treated with curative radiation therapy, whether conventional or stereotactic body radiation therapy (SBRT). Methods and Materials: Between January 2007 and December 2011, a total of 163 patients (180 tumors) with medically inoperable histologically proven Stage T1 or T2N0 NSCLC and treated with radiation therapy (both conventional and SBRT) were entered in a research ethics boardmore » approved database. All patients received pretreatment FDG-PET / computed tomography (CT) at 1 institution with consistent acquisition technique. The medical records and radiologic images of these patients were analyzed. Results: The overall survival at 2 years and 3 years for the whole group was 76% and 67%, respectively. The mean and median SUV{sub max} were 8.1 and 7, respectively. Progression-free survival at 2 years with SUV{sub max} <7 was better than that of the patients with tumor SUV{sub max} ≥7 (67% vs 51%; P=.0096). Tumors with SUV{sub max} ≥7 were associated with a worse regional recurrence-free survival and distant metastasis-free survival. In the multivariate analysis, SUV{sub max} ≥7 was an independent prognostic factor for distant metastasis-free survival. Conclusion: In early-stage NSCLC managed with radiation alone, patients with SUV{sub max} ≥7 on FDG-PET / CT scan have poorer outcomes and high risk of progression, possibly because of aggressive biology. There is a potential role for adjuvant therapies for these high-risk patients with intent to improve outcomes.« less
  • Purpose: To establish whether {sup 18}F-3'-deoxy-3'-fluoro-L-thymidine ({sup 18}F-FLT) can monitor changes in cellular proliferation of non-small-cell lung cancer (NSCLC) during radical chemo-radiotherapy (chemo-RT). Methods and Materials: As part of a prospective pilot study, 5 patients with locally advanced NSCLC underwent serial {sup 18}F-FLT positron emission tomography (PET)/computed tomography (CT) scans during treatment. Baseline {sup 18}F-FLT PET/CT scans were compared with routine staging {sup 18}F-FDG PET/CT scans. Two on-treatment {sup 18}F-FLT scans were performed for each patient on Days 2, 8, 15 or 29, providing a range of time points for response assessment. Results: In all 5 patients, baseline lesional uptakemore » of {sup 18}F-FLT on PET/CT corresponded to staging {sup 18}F-FDG PET/CT abnormalities. {sup 18}F-FLT uptake in tumor was observed on five of nine (55%) on-treatment scans, on Days 2, 8 and 29, but not Day 15. A 'flare' of {sup 18}F-FLT uptake in the primary tumor of one case was observed after 2 Gy of radiation (1.22 x baseline). The remaining eight on-treatment scans demonstrated a mean reduction in {sup 18}F-FLT tumor uptake of 0.58 x baseline. A marked reduction of {sup 18}F-FLT uptake in irradiated bone marrow was observed for all cases. This reduction was observed even after only 2 Gy, and all patients demonstrated a complete absence of proliferating marrow after 10 Gy. Conclusions: This proof of concept study indicates that {sup 18}F-FLT uptake can monitor the distinctive biologic responses of epithelial cancers and highly radiosensitive normal tissue changes during radical chemo-RT. Further studies of {sup 18}F-FLT PET/CT imaging during therapy may suggest that this tracer is useful in developing response-adapted RT for NSCLC.« less
  • This study was designed to analyze if reliable non-invasive therapy response monitoring can be obtained with positron emission tomography (PET) using F-18 labeled deoxyglucose (FDG). Furthermore, if the PET response classification at an early time point during chemotherapy, after the second or third therapy cycle, correlates with the patient survival data, which is the most reliable measure of therapy outcome. A homogeneous patient population, 39 patients with histologically confirmed SCLC, performance status {<=} 2 ECOG were studied. The study lasted from 1988-1993, with survival data of all patients known. The overall survival time was 17.1 months with a range ofmore » 3-56. Three independent response classifications techniques were compared: (a) clinical evaluation including all imaging studies except PET, (b) NSE tumor marker, and (c) PET response classification. For each technique three categories were used: (1) no change/progressive disease (NC/PD), (II) partial response (PR) and (III) complete remission (CR). The survival data in months based on the classification after the second cycle is shown in the table with the range of survival in month in parentheses.« less