A 62-year-old woman undergoes total gastrectomy with D2 lymphadenectomy for gastric cancer. Histopathology shows T3N2M0 disease. Before adjuvant chemotherapy, which investigation is most appropriate to confirm the absence of distant metastases and assess baseline organ function?

Explanation

## Metastatic Workup in Gastric Cancer **Key Point:** After curative-intent gastrectomy, **CT chest, abdomen, and pelvis** is the standard investigation to: 1. Confirm **M0 status** (absence of distant metastases) 2. Assess for occult peritoneal, hepatic, or pulmonary disease 3. Establish baseline before adjuvant chemotherapy 4. Detect recurrence on follow-up imaging ### Timing and Rationale for CT in Postoperative Workup | Scenario | Investigation | Indication | |---|---|---| | **Pre-operative staging** | EUS + CT abdomen/pelvis | Assess T, N, M stages | | **Post-operative (after curative surgery)** | **CT chest/abdomen/pelvis** | Confirm M0, detect occult disease, baseline for follow-up | | **Suspected peritoneal metastases** | Diagnostic laparoscopy ± washings | Cytologic diagnosis if imaging inconclusive | | **Recurrence surveillance** | CT abdomen/pelvis ± chest | Every 6–12 months for 2 years | **High-Yield:** In **T3N2M0 gastric cancer**, the risk of occult metastases is significant. CT is essential to: - Exclude liver metastases (most common site, ~40% of recurrences) - Detect peritoneal nodules or ascites suggesting peritoneal carcinomatosis - Assess for distant lymph node involvement (retroperitoneal, supraclavicular) - Ensure patient is truly M0 before committing to adjuvant chemotherapy **Clinical Pearl:** Postoperative CT should be performed **4–6 weeks after surgery** to allow resolution of surgical inflammation and prevent false-positive findings. Earlier imaging may overestimate disease extent due to edema and reactive changes. ### Why Other Options Are Incorrect **Staging Laparoscopy:** - Useful **preoperatively** if imaging suggests peritoneal disease but diagnosis is uncertain - Not indicated **postoperatively** after already-completed gastrectomy - Invasive and offers no additional benefit once resection is complete **Diagnostic Laparotomy:** - Rarely indicated in modern practice - Patient has already undergone surgery; reoperation without imaging guidance is not justified **PET-CT with Brain MRI:** - PET-CT may be used selectively for detecting distant metastases in high-risk patients - Brain MRI is not routine unless neurologic symptoms present (gastric cancer rarely metastasizes to brain) - More expensive and not standard postoperative workup **Mnemonic:** **PACT** for postoperative gastric cancer surveillance — **P**ost-op, **A**ssess **C**T for **T**rue M0 status.