324P - Radiation response assessment by hybrid positron emission tomography/magnetic resonance imaging for cervical cancer treatment
|Date||18 December 2016|
|Event||ESMO Asia 2016 Congress|
|Topics|| Cervical Cancer
Imaging, Diagnosis and Staging
Surgery and/or Radiotherapy of Cancer
|Presenter||Bok Ai Choo|
|Citation||Annals of Oncology (2016) 27 (suppl_9): ix94-ix103. 10.1093/annonc/mdw585|
B.A. Choo1, V. Koh1, J. Tang1, J. Low1, M.C. Stephenson2, D.L. Cheong2, E. Laurens2, J.J. Totman2, J.S. Ng1, S. Roy2
Treatment response after radiation therapy (RT) in locally advanced cervical cancer is commonly 2-3 months post-therapy. We aim to investigate the ability of hybrid PET-MRI to visualize tumour changes during the initial radiation phase, to optimise and personalised radiation dosage.
All patients received four or five insertions of ring (Vienna) or ovoid (Utrecht) MRI compatible based brachytherapy in addition to five and half weeks of daily external RT. With the mandatory written informed consent, four multi-parametric PET/MRI scans comprising of dynamic contrast-enhance imaging and diffusion weighted imaging were performed on each patient. The patients were examined first with 6mCi 18F-FDG scan at baseline. Prior to the first and third brachytherapy insertions, the patients were examined with the second and third 3mCi 18F-FDG scans respectively. The last scan was performed 3 months post-treatment with 6mCi 18F-FDG as this will act as a prognosticator tool to assess whether a complete response has been achieved.
We report results of our pilot study. Aging between 46-55 years, all patients had histopathologically confirmed cervical cancer. On PET, metabolic target volume was 15.5-22.6 cm3 at baseline, with SUVmax 6.0-7.5 and SUVmean 4.3-5.4. MRI region of interest volume at baseline was 12.3-114.7 cm3. Good radiological treatment response was shown by all patients on both PET and MRI, with observations typically reflecting largest variation between the baseline and second scan (post external RT). A mid-treatment increase in SUV occurred to one patient due to additional interstitial needle insertion during brachytherapy. At 3 months post-treatment, all patients attained complete radiological response. To date, there are no clinical locoregional recurrences.
Significant treatment response to RT can be detected early using PET/MRI, typically by end of external beam RT. The intention is to establish this finding through patient accrual. Personalized treatment concordant to tumour response may be developed. This will help to enhance cure rate and reduce potential side effects by giving a personalised radiation dose to the tumour rather than a standard protocolised dose.
Clinical trial indentification
National University Hospital Singapore Institutional Review Board approved protocol number 2013/00052
Legal entity responsible for the study
National University Hospital Singapore
National Cancer Institute Singapore
All authors have declared no conflicts of interest.