Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul-Aug;20(4):796-806.
doi: 10.1016/j.brachy.2021.03.019. Epub 2021 May 14.

Characterization of combined intracavitary/interstitial brachytherapy including oblique needles in locally advanced cervix cancer

Monica Serban  1 , Lars Fokdal  2 , Søren Kynde Nielsen  2 , Steffen Bjerre Hokland  2 , Anders Traberg Hansen  2 , Harald Spejlborg  2 , Susanne Rylander  2 , Primoz Petric  3 , Jacob Christian Lindegaard  2 , Kari Tanderup  2
Affiliations

Characterization of combined intracavitary/interstitial brachytherapy including oblique needles in locally advanced cervix cancer

Monica Serban et al. Brachytherapy. 2021 Jul-Aug.

Abstract

Purpose: To characterize and report on dosimetric outcomes of image guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) applicators including oblique needles (O-needles) in locally advanced cervical cancer (LACC).

Methods and materials: Twenty LACC patients treated with radio-chemotherapy and offered IC/IS-IGABT including O-needles were analyzed. An in-house 3D-printed vaginal template was used to steer the needles parallel and obliquely in relation to the tandem, supplemented with free-hand needles if needed. Implant characteristics and loading patterns were analyzed. Using the equivalent dose in 2Gy-fractions (EQD2) concept, cumulative (EBRT+BT) V85, V75, V60Gy, targets/OARs doses and high dose volumes (150%, 200% and 300% (100% = 85 Gy EQD210)) were evaluated.

Results: Median(range) tumor width at diagnosis was 5.5(3.6; 7.5)cm; CTVHR volume was 45(23; 136)cm3 with maximum distance from tandem to CTVHR border of 3.4(2.5; 4.8)cm. T-stage distribution was IIB/III/IVA in 6(30%)/9(45%)/5(25%) of patients. At BT, 13(65%) patients had distal parametrial/pelvic wall infiltration. Median(range) number of needles per patient was 11(8-18). Average distribution of intrauterine, vaginal and interstitial dwell times were 31%, 25% and 44%, respectively. Median(range) dwell-time per dwell position was 11(2-127)% of average point-A based standard loading. Median V85Gy/V150%/V200%/V300% were 85(38; 171)/41(21; 93)/22(12; 41)/7(4; 19) cm3; CTVHR D90% was 93(83; 97)Gy EQD210; bladder/rectum/sigmoid/bowel D2cm3 were 78(64; 104)/65(52; 76)/59(53; 69)/61(47; 76)Gy EQD23.

Conclusions: The use of O-needles in patients with large and/or unfavorable tumors resulted in excellent target coverage and OARs sparing. Intrauterine and vaginal loadings were reduced compared to standard loading and almost half of the loading was shifted into IS needles. This was achieved with gentle loading in the majority of dwell positions.

Keywords: Cervix cancer; Intracavitary and interstitial brachytherapy; MR-guided adaptive brachytherapy; Parallel and oblique needles.

PubMed Disclaimer

Publication types