Vaginal dose de-escalation in image guided adaptive brachytherapy for locally advanced cervical cancer.
Vaginal stenosis is a major problem following radiotherapy in cervical cancer. We investigated a new dose planning strategy for vaginal dose de-escalation (VDD).



Fifty consecutive locally advanced cervical cancer patients without lower or middle vaginal involvement at diagnosis from 3 institutions were analysed. External beam radiotherapy was combined with MRI-guided brachytherapy. VDD was obtained by decreasing dwell times in ovoid/ring and increasing dwell times in tandem/needles. The aim was to maintain the target dose (D90 of HR-CTV⩾85Gy EQD2) while reducing the dose to the surface of the vagina to <140% of the physical fractional brachytherapy dose corresponding to a total EQD2 of 85Gy.



The mean vaginal loading (ovoid/ring) was reduced from 51% to 33% of the total loading with VDD, which significantly reduced the dose to the vaginal dose points (p<0.001) without compromising the target dose. The dose to the ICRU recto-vaginal point was reduced by a mean of 4±4Gy EQD2 (p<0.001), while doses to bladder and rectum (D2cm3) were reduced by 2±2Gy and 3±2Gy, respectively (p<0.001).



VDD significantly reduces dose to the upper vagina which is expected to result in reduction of vaginal stenosis.
Department of Oncology, Aarhus University Hospital, Denmark; Department of Radiotherapy, NCI, Cairo University, Egypt. Electronic address: sandy.mohamed@nci.cu.edu.eg.
Sandy
S
Mohamed
Department of Oncology, Aarhus University Hospital, Denmark.
Jacob Christian
JC
Lindegaard
Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands.
Astrid A C
AA
de Leeuw
Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands.
Ina
I
Jürgenliemk-Schulz
Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna, Austria.
Kathrin
K
Kirchheiner
Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna, Austria.
Christian
C
Kirisits
Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna, Austria.
Richard
R
Pötter
Institute of Clinical Medicine, Aarhus University, Denmark.
Kari
K
Tanderup
D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D003251:Constriction, Pathologic / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods*; D058958:Organs at Risk / Q000528:radiation effects; D011446:Prospective Studies; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012007:Rectum / Q000528:radiation effects; D001743:Urinary Bladder / Q000528:radiation effects; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*; D014621:Vagina / Q000528:radiation effects*; D014623:Vaginal Diseases / Q000209:etiology / Q000517:prevention & control
Brachytherapy; Cervical cancer; Dose de escalation; MRI guided; Radiation dose; Vaginal dose