TY - JOUR
T1 - Addition of Iodinated Contrast to Rectal Hydrogel Spacer to Facilitate MRI-Independent Target Delineation and Treatment Planning for Prostate Cancer
AU - Atluri, Pramukh S.
AU - Gannavarapu, Bhavani S.
AU - Timmerman, Robert D.
AU - Garant, Aurelie
AU - Hannan, Raquibul
AU - Folkert, Michael R.
AU - Desai, Neil B.
N1 - Publisher Copyright:
© 2019 American Society for Radiation Oncology
PY - 2019/11
Y1 - 2019/11
N2 - Purpose: Hydrogel spacers reduce rectal dose toxicity during prostate cancer radiation therapy. Current products require magnetic resonance imaging (MRI) for visualization during treatment planning, but MRI incompatibility and cost have prompted alternatives using computed tomography (CT). This case series evaluates the addition of iodinated contrast to hydrogel as such an alternative. Methods and materials: Three patients underwent rectal hydrogel spacer placement with iodinated contrast modification. CT was performed within 1 hour of injection and again 1 week later. MRI was obtained at the time of the second CT. Hydrogel delineation was compared between CT and MRI and between paired CT scans. Results: Spacer enhancement was visible on CT immediately after hydrogel placement (mean Hounsfield units, 122; range, 52-193) but not at the second CT 1 week later (mean Hounsfield units, 8; range, −8 to 29). Delineated spacer volume did not significantly differ between immediate postprocedure CT and MRI ≥1 week later in 2 patients (patient 1: 16.6 vs 15.5 cm3; patient 2: 12.6 vs 14.7 cm3; paired t-test, P = .81). Conclusions: CT visualization of rectal hydrogel admixed with contrast is feasible and allows delineation of interface with rectum/prostate.
AB - Purpose: Hydrogel spacers reduce rectal dose toxicity during prostate cancer radiation therapy. Current products require magnetic resonance imaging (MRI) for visualization during treatment planning, but MRI incompatibility and cost have prompted alternatives using computed tomography (CT). This case series evaluates the addition of iodinated contrast to hydrogel as such an alternative. Methods and materials: Three patients underwent rectal hydrogel spacer placement with iodinated contrast modification. CT was performed within 1 hour of injection and again 1 week later. MRI was obtained at the time of the second CT. Hydrogel delineation was compared between CT and MRI and between paired CT scans. Results: Spacer enhancement was visible on CT immediately after hydrogel placement (mean Hounsfield units, 122; range, 52-193) but not at the second CT 1 week later (mean Hounsfield units, 8; range, −8 to 29). Delineated spacer volume did not significantly differ between immediate postprocedure CT and MRI ≥1 week later in 2 patients (patient 1: 16.6 vs 15.5 cm3; patient 2: 12.6 vs 14.7 cm3; paired t-test, P = .81). Conclusions: CT visualization of rectal hydrogel admixed with contrast is feasible and allows delineation of interface with rectum/prostate.
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U2 - 10.1016/j.prro.2019.05.013
DO - 10.1016/j.prro.2019.05.013
M3 - Article
C2 - 31173917
AN - SCOPUS:85068542309
SN - 1879-8500
VL - 9
SP - e528-e533
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 6
ER -