Anindita Das, (2020) Integration of fluorodeoxyglucose F-18 positron emission tomography-computed tomography (FDG F-18 PET-CT, or FDG PET-CT) in radiotherapy planning for patients with stage III inoperable locally advanced non-small cell lung cancers. Masters thesis, Christian Medical College, Vellore.
|
Text
2009 01120anindita_das.pdf Download (5MB) | Preview |
Abstract
OBJECTIVES: To assess the benefits of FDG F-18 PET-CT based radiotherapy planning versus CECT based planning in patients with inoperable stage-III non-small cell lung cancer (NSCLC) in terms of volumetric changes in tumour volumes and OAR doses, and the prognostic significance of quantitative metabolic parameters calculated from PET-CT and serial change in tumour volume observed on CBCTs. METHODS: 21 patients with stage-III inoperable NSCLC fulfilling the inclusion criteria were recruited. All of them underwent whole-body FDG F18 PET-CT in planning position with RT markers. Two sets of target volumes and an OAR structure set were contoured on PET-CT and CT images using which two separate VMAT plans were generated; the PET-CT based plan was used for subsequent quality assurance and treatment. Concurrent chemotherapy was also administered. The tumour was contoured on weekly CBCTs during treatment. Patients were followed up at 3 months after treatment with PET-CT, and every thereafter 3-monthly for one year or till first recurrence, if earlier. The difference in target volumes and OAR doses between the two plans were analysed. Quantitative metabolic parameters viz. SUVmean, SUVmax, MTV and TLG from baseline and follow-up PET-CTs, as well as tumour volume reduction on serial CBCTs were analysed for PFS correlation. SPSS-23.0 was used for statistical analysis using p-value <0.05. Descriptive parameters were analysed using frequency, percentage, or mean+/-SD as appropriate. Pearson's correlation, two independent sample t-test and one-way analysis of variance were done. RESULTS: Mean primary GTV, total GTV, CTV and PTV volumes were lower on the PET-CT contours, while mean nodal GTV was higher. Mean OAR doses were lower on the plan generated using PET-CT based contour for lungs, heart, spinal cord and brachial plexus, but showed variable results for oesophagus. Mean PFS was lesser when baseline SUVmax, TLG, or MTV were high; while mean PFS was longer when there was a greater reduction in these parameters post-treatment. Greater tumour volume reduction seen on serial CBCTs during RT showed a trend towards longer PFS. CONCLUSION: Although none of these results attained statistical significance, PET-CT appears to have a role in the management of lung cancer at various phases: accurate staging, better RT planning by virtue of better demarcated tumour volumes and sparing of normal lung, better detection of involved nodes to prevent geographic miss, reduced OAR doses which might further reflect as reduced normal tissue toxicities. Baseline levels of quantitative metabolic parameters from PET-CT and their reduction post treatment, as well as the magnitude of serial tumour volume reduction on CBCTs, may also act as a potential early indicators of outcome.
| Item Type: | Thesis (Masters) |
|---|---|
| Additional Information: | 201719051 |
| Uncontrolled Keywords: | Lung cancer, non-small cell, concurrent chemoirradiation, PET-CT, quantitative metabolic parameters, VMAT, IGRT, CBCT. |
| Subjects: | MEDICAL > Radio Therapy |
| Depositing User: | Subramani R |
| Date Deposited: | 01 Feb 2021 03:12 |
| Last Modified: | 01 Feb 2021 03:12 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/13636 |
Actions (login required)
 |
View Item |
