Accelerated diagnostic pathway for undifferentiated malignancy via interventional radiology triage: A comparative effectiveness study.

1568 Background: Efficiently triaging patients presenting with imaging findings suggestive of malignancy but lacking a definitive tissue diagnosis poses a considerable challenge for large cancer centers. Without a tissue diagnosis in the setting of metastatic disease it is unclear which specialized medical oncologist would be the optimal physician to see the patient. Traditional referral patterns may lead to significant diagnostic delays until the patient reaches the appropriate oncologist. We evaluated the efficacy of a dedicated "Rapid Biopsy" (RB) pathway, which directs such patients immediately to the Interventional Radiology (IR) Outpatient Clinic for streamlined, image guided diagnosis and compared this new pathway to the traditional, standard institutional referral approach. Methods: This retrospective cohort study included 1157 patients at Memorial Sloan Kettering Cancer Center (MSKCC) who underwent a first diagnostic biopsy between 2020 and 2023. The cohort comprised 532 patients from the prospectively enrolled RB program and 625 patients in a rigorously matched comparison cohort (CC), derived from standard referrals who presented with an "unknown primary" malignancy, excluding any patient with a history of prior tissue sampling or recurrence. The primary endpoints were the mean time from initial consultation to biopsy and the mean time from initial consultation to treatment initiation. Independent t-tests were used for cohort comparison. Patients exhibiting outlier time-to-treatment intervals exceeding 90 days were excluded from the treatment analysis. Results: The RB and CC cohorts were well-matched demographically (mean age RB: 65.75 years; CC:66.05 years). Malignancy was confirmed in 90.4% and 92.3% of the respective cohorts. The RB pathway demonstrated a 71% reduction in time from initial consult to biopsy than the CC (4.59 vs 15.66 days, p<0.001), representing an 11.07 reduction. Furthermore, this operational efficiency translated into a 63% reduction in time from initial consult to treatment compared to the CC (14.57 vs 39.88 days, p<0.001), achieving an 11.88 day reduction in time to start. Conclusions: The dedicated Interventional Radiology first Rapid Biopsy pathway provided a clinically significant meaningful acceleration in the cancer diagnostic and treatment process, saving 11 days from consult to biopsy and nearly 12 days to definitive treatment initiation. This model effectively streamlines care by eliminating multi-specialty diagnostic detours prevalent in traditional triage, establishing a crucial operational standard for comprehensive cancer centers managing new suspected malignancies.