Abstract
This thesis focused on the validation of FDG-PET/CT in the radiotherapy treatment planning for patients with esophageal cancer to determine whether the use of PET/CT results in a more adequate radiotherapy and treatment outcome.
FDG-PET/CT results in changes in radiotherapy target volumes and consequently adjusted radiotherapy treatment plans. However, it remains questionable whether the PET/CT-based target volume also represents the true tumor volume.
After CT-based neo-adjuvant (chemo)radiotherapy, microscopic tumour was found outside the margin for microscopic tumour in a substantial part of the patients at pathologic evaluation, which had an negative impact on survival. These results suggests inaccurate tumour volume delineation, inadequate margins and/or tumour growth.
The RESPECT trial was undertaken to validate the additional value of PET/CT clinically. The endpoint was the proportion of locoregional recurrences that could have been prevented if the radiotherapy treatment planning for esophageal cancer was based on PET/CT instead of CT. Locoregional recurrences were seen in 11% of the patients. Accurate recurrence analysis showed that none of these locoregional recurrences were preventable by the use of PET/CT. These results suggest a limited value of PET/CT for radiotherapy planning, in terms of preventing locoregional recurrences.
The PET/CT for radiotherapy planning can be useful for patient selection and delineation of pathologic lymph nodes. Esophageal cancer can progress rapidly, even in the time between the diagnostic PET/CT and the one for radiotherapy planning. A planning PET/CT might reveal new pathologic lymph nodes or distant metastases.
FDG-PET/CT results in changes in radiotherapy target volumes and consequently adjusted radiotherapy treatment plans. However, it remains questionable whether the PET/CT-based target volume also represents the true tumor volume.
After CT-based neo-adjuvant (chemo)radiotherapy, microscopic tumour was found outside the margin for microscopic tumour in a substantial part of the patients at pathologic evaluation, which had an negative impact on survival. These results suggests inaccurate tumour volume delineation, inadequate margins and/or tumour growth.
The RESPECT trial was undertaken to validate the additional value of PET/CT clinically. The endpoint was the proportion of locoregional recurrences that could have been prevented if the radiotherapy treatment planning for esophageal cancer was based on PET/CT instead of CT. Locoregional recurrences were seen in 11% of the patients. Accurate recurrence analysis showed that none of these locoregional recurrences were preventable by the use of PET/CT. These results suggest a limited value of PET/CT for radiotherapy planning, in terms of preventing locoregional recurrences.
The PET/CT for radiotherapy planning can be useful for patient selection and delineation of pathologic lymph nodes. Esophageal cancer can progress rapidly, even in the time between the diagnostic PET/CT and the one for radiotherapy planning. A planning PET/CT might reveal new pathologic lymph nodes or distant metastases.
| Translated title of the contribution | Het gebruik van PET/CT bij de radiotherapeutische behandeling van het oesofaguscarcinoom |
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| Original language | English |
| Qualification | Doctor of Philosophy |
| Awarding Institution |
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| Supervisors/Advisors |
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| Award date | 7-May-2014 |
| Place of Publication | [S.l.] |
| Publisher | |
| Print ISBNs | 978-90-367-6947-1 |
| Electronic ISBNs | 978-90-367-6948-8 |
| Publication status | Published - 2014 |