(P 345) CLINICIAN SURVEY - CURRENT GLOBAL PRACTICE FOR SARCOMA SURVEILLANCE FOLLOWING RESECTION OF PRIMARY RETROPERITONEAL, ABDOMINAL, AND PELVIC SARCOMA

Objective: Postoperative surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma is standard of care in international high-volume sarcoma centres and has rapidly evolved without an evidence base to become highly intensive and prolonged within most centres. This clinician survey aims to capture a global, contemporary snapshot of international guidelines used to inform sarcoma surveillance following resection of primary retroperitoneal, abdominal, and pelvic sarcoma.

Methods: Between July 2022 and March 2023, a link to an online cross-sectional, self-reported clinician survey consisting of 33 questions to assess the current duration, imaging intervals and imaging modalities used for postoperative surveillance following resection of primary retroperitoneal, abdominal, and pelvic soft tissue sarcoma was sent via individual e-mails to clinicians working at centres which are members of the TransAtlantic Australasian Retroperitoneal Working Group (TARPSWG). In addition, the questions assessed which national or international guidelines form the basis for current practice within the institution. Questions differentiated between surveillance strategies for low-grade and high-grade tumours. The questionnaire was anonymous and distribution and management occurred via the secure JISC Online Survey Platform. Descriptive statistics were calculated for each of the measurement items.

Results: Survey responses were received from 58 different TARPSWG centres. Geographically centres are located in Europe (n=28, 48%), North America (n=20, 34%), Asia (n=5, 9%) South America (n=3, 5%) and Australia (n=2, 4%). The majority of centres use institutional guidelines to guide surveillance intensity (n=43, 74%) and the surveillance imaging modality used (n 39, 67 %). For surveillance intensity and imaging modality, institutional guidelines are partially or entirely based on international guidelines in 81% (n=47) and 78% (n=45) of centres respectively. Influential international guidelines were the Practice Guidelines of the National Comprehensive Cancer Network (NCCN) (n=11, 19%), the Soft tissue and visceral sarcomas ESMO-EURACAN Clinical Practice Guidelines (n=2, 3%), the TARPSWG - Consensus approach on the management of Primary Retroperitoneal Sarcoma in the adult (n=5, 9%) and the UK guidelines for the management of soft tissue sarcomas (n=2, 3%), with 47% (n=27) of centres using a combination of two or more international guidelines to inform their practice. Imaging modalities used for chest surveillance are plain chest radiography (n=7, 12%), non-contrast enhanced CT chest (n=25, 43%), contrast-enhanced CT chest (n=19, 33%), high-resolution CT chest (n=4, 7%), and no chest imaging (n=3, 5%). For abdominal surveillance, the following imaging modalities are used: plain abdominal radiography (n=1, 2%), non-contrast enhanced CT abdomen-pelvis (n=2, 3%), contrast-enhanced CT abdomen-pelvis (n=51, 88%), and MRI abdomen-pelvis (n=4, 7%). Imaging intervals, timing of de-escalation of imaging intervals and total duration of surveillance for low-grade and high-grade retroperitoneal, abdominal, and pelvic soft tissue sarcoma are shown in Figure 1 and Figure 2, respectively.

Conclusion: This global survey among TARPSWG members demonstrates the heterogeneity in sarcoma surveillance strategies worldwide and emphasises the need for a randomised controlled trial to provide an evidence base for the optimal surveillance schedule following primary resection of retroperitoneal, abdominal, and pelvic soft tissue sarcoma. The results of this survey will be utilised to compare intended versus observed surveillance intensity as part of a retrospective study of surveillance outcomes launched via the TARPSWG platform.