Vienna, Austria

ESTRO 2023

Session Item

Gynaecological
6014
Poster (Digital)
Clinical
IORT AT THE TIME OF PELVIC EXENTERATION IN PERSISTENT OR RECURRENT GYNECOLOGIC MALIGNANCIES
PO-1413

Abstract

IORT AT THE TIME OF PELVIC EXENTERATION IN PERSISTENT OR RECURRENT GYNECOLOGIC MALIGNANCIES
Authors:

Stefano Durante1, Roberta Lazzari1, Giulia Corrao2, Sabrina Vigorito3, Federica Cattani3, Alessia Aloisi4, Vanna Zanagnolo4, Angelo Maggioni4, Nicoletta Colombo5,6, Barbara Alicja Jereczek-Fossa1,7

1European Institute of Oncology, IRCCS, Division of Radiation Oncology, Milan, Italy; 2European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy; 3European Institute of Oncology, IRCCS, Unit of Medical Physics, Milan, Italy; 4European Institute of Oncology, IRCCS, Department of Gynecology, Milan, Italy; 5European Institute of Oncology, IRCCS, Department of Oncological Gynecology, Milan, Italy; 6University of Milan-Bicocca, School of Medicine and Surgery, Milan, Italy; 7University of Milan, Department of Oncology and Hemato-oncology, Milan, Italy

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Purpose or Objective

Intraoperative radiotherapy (IORT) is a modality that allows for a additional high, single radiation dose to be delivered safely while minimizing the dose to adjacent normal tissues.  For this reason, IORT is well suited as an adjunct to tumor resection in patient with persistent or recurrent gynecologic malignancies undergoing pelvic exenteration (PE).

The present study aimed to review our experience using IORT at the time of PE, in terms of disease free survival (DFS) and overall survival (OS).

Material and Methods

We conducted a retrospective monocentric study from January 2001 to March 2019. Inclusion criteria were the following: 1) patients with a diagnosis of persistent or recurrent, previously heavy treated, gynecologic malignancies who underwent planned PE with curative intent; 2) all gynecological cancer were considered; 3) IORT administration planned for not radical surgical margin (SM), positive lymphonodes or microscopic disease extended to <1 mm of the resection SM.

Results

Overall 55 patients mactched inclusion criteria. Baseline characeristics are summarized in table 1.
IORT was delivered because of positive lymph nodes in 12 cases, of positive SM in 19 cases and in 24 patients because microscopic disease extended to <1 mm of the resection margins.  
The median follow-up was 35 months (range, 3-152 months). Overall 3-year DFS was 34.7% (median 11.8 months, 95% CI 6.1-17.6) and 3-year OS was 41.8% (median 24 months, 95% CI 14.5-33.5).
SM were classified as negative (36 of 55, 65.5 %) or positive (19 of 55, 34.5%). The 3-year local control rate was 64.4% in patients with negative SM compared to 45.7% in patients with positive SM (P=0.6). 

23 patients relapsed (57.5%), 18 of those in the IORT field. The identified risk factors associated with high risk of recurrence in field of IORT were cervical cancer (HR 10.3, 95% CI 1.2-86.5, P=0.03) and Grade 3 histology (HR 10, 95% CI 1.1-95.2, P=0.04). We also observed a trend in the correlation between positive SM and risk of recurrence in IORT field.

Table 1: Patients’ Characteristics (N=55)



Conclusion

Survival in patients with high risk to have positive margin at final pathology after radical surgery alone showing particularly dismal survival rates. IORT is a viable option during pelvic exenteration for recurrent or persistent gynecological cancer still, with limited data, that might be considered to consolidate areas at high risk of relapse due to close or microscopically positive margins.

Whether IORT can improve local recurrence rates will require further prospective investigation.