Copenhagen, Denmark
Onsite/Online

ESTRO 2022

Session Item

Gynaecological
6014
Poster (digital)
Clinical
Long- term outcomes after electronic brachytherapy in the adjuvant treatment of endometrial cancer.
Maria Cerrolaza, Spain
PO-1339

Abstract

Long- term outcomes after electronic brachytherapy in the adjuvant treatment of endometrial cancer.
Authors:

María Cerrolaza1, Agustina Mendez1, Anabela Miranda1, Victoria Navarro1, Cecilia Escuin1, Arantxa Campos1, Sonia Flamarique1, Marina Gascon1, Sergio Lozares2, Reyes Ibañez1

1University Hospital Miguel Servet, Radiotherapy, ZARAGOZA, Spain; 2University Hospital Miguel Servet, Physics, ZARAGOZA, Spain

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Purpose or Objective

Intracavitary brachytherapy is a fundamental treatment in the adjuvant treatment of endometrial cancer, reducing vaginal vault recurrences. The most common form of administration is HDR brachytherapy with Iridium-192 but electronic brachytherapy is proposed as an alternative.

Our objective has been to evaluate the effectiveness and toxicities observed in the long term of electronic brachytherapy (eBQT) in the treatment of endometrial cancer. 

Material and Methods

Patients with endometrial cancer treated with intracavitary eBQT between October 2015 and September 2016 were retrospectively analyzed. eBQT was administered by cylindrical applicators with a dose of 15 Gy (5Gy/fraction) after previous external radiotherapy (EBRT) with a dose of 46 Gy (2Gy/fraction) and 25 Gy (5Gy/fraction) in those who underwent adjuvant exclusively.

Their history, oncologic and dosimetric data, acute toxicities (<90 days) and late toxicities (>90 days) according to the CTCAE v.5 scale, recurrences and exits during follow-up were analyzed.

Statistical analysis was performed with Student's t-test and Chi-square test.  P values < 0.05 were considered statistically significant.

Results

Thirty-six patients with a mean age of 64.56 years were collected. Endometrioid carcinoma was diagnosed in 77.8%, serous carcinoma in 11.1%, carcinosarcoma in 5.6% and clear cell carcinoma in 5.6%. VILI was present in 33.3% and 58.3% had a depth of more than 50% of the myometrium. 22.2% were grade 1, 41.67% G2 and 36.11% G3 or poorly differentiated. 86.11% were classified as FIGO I-II. TEN was performed over the pelvis in 20 patients (56%).

The diameters of the applicators used were 2.5, 3 and 3.5 in 8%, 42% and 50% respectively. The active length treated was 2.5 cm in 19% and 3 cm in 81%.

25 patients (69.4%) presented some type of acute toxicity: rectal toxicity 13, urinary toxicity 12 and on vaginal mucosa 13, with no G3 toxicity observed. 8 patients (22.2%) presented some type of late toxicity: urinary toxicity 1, rectal toxicity 4 and on vaginal mucosa 6, none of them G3.

A statistically significant association was found between TEN and acute rectal toxicity (p= 0.008).

With a follow-up of 67.48 months 9 patients have relapsed (25%). 7 patients at a distance, 1 through pelvic adenopathies and 1 in the lower third of the vagina (not irradiated). 6 patients have died, 4 of them due to their oncologic disease (11.11%).

A statistically significant association was found between myometrial invasion greater than 50% and recurrence (p= 0.032) as well as exitus with oncologic history (p=0.038), histology type 1-2 (p=0.033) and FIGO stage (p= 0.010). 

Conclusion

Electronic brachytherapy on vaginal vault in the adjuvant treatment of endometrial cancer is an effective technique with good tolerance.