What are the necessary preoperative investigations for carcinoma of the vulva (Ca vulva)?

Preoperative Investigations for Vulvar Carcinoma

For patients with vulvar carcinoma, preoperative investigations should include MRI of the pelvis without and with IV contrast for tumors >2 cm, and FDG-PET/CT from skull base to mid-thigh for tumors >4 cm or with significant involvement of adjacent structures. 1

Initial Assessment Based on Tumor Size and Invasion

Small Tumors (≤2 cm, ≤1 mm invasion)

• Clinical examination alone is usually sufficient
• Imaging typically not necessary 1
• No lymph node evaluation required due to <1% risk of lymphatic metastases 1

Intermediate Tumors (≤4 cm, >1 mm invasion)

• MRI pelvis without and with IV contrast - recommended to define extent of primary tumor and assess inguinofemoral lymph node (IFLN) basins 1
• Consider vaginal gel during MRI to better delineate vaginal involvement 1
• Lymph node evaluation required due to >8% risk of lymphatic metastases 1

Large/Advanced Tumors (>4 cm or significant involvement of adjacent structures)

• MRI pelvis without and with IV contrast AND FDG-PET/CT from skull base to mid-thigh - both recommended and considered complementary for comprehensive staging 1
• CT chest, abdomen, and pelvis with IV contrast - acceptable alternative if MRI unavailable 1

Lymph Node Assessment

For tumors >1 mm invasion:

• Imaging assessment of inguinofemoral lymph nodes is critical as lymph node status is the most important prognostic factor 1, 2
• For tumors <2 cm from midline: bilateral lymph node evaluation required 1
• For tumors ≥2 cm from midline: unilateral lymph node evaluation on the same side as the tumor 1
• Ultrasound with duplex Doppler and ultrasound-guided fine-needle aspiration biopsy may be appropriate to confirm suspected lymph node metastases 1

Special Considerations

Imaging Criteria for Lymph Node Metastasis

• Short-axis to long-axis diameter ratio >0.75 has 86.7% sensitivity and 81.3% specificity 1
• On CT, lymph nodes >10 mm in short-axis diameter and/or abnormal enhancement pattern suggest metastasis (60% sensitivity, 90% specificity) 1

Pitfalls to Avoid

• Do not rely solely on clinical examination for lymph node assessment - has limited sensitivity
• Do not omit imaging for tumors with >1 mm invasion, as depth of invasion correlates strongly with lymph node metastasis risk 2
• Do not perform routine chest radiography - has limited value in initial staging and does not alter gynecologic management 1
• Avoid unnecessary imaging for very small tumors (≤2 cm with ≤1 mm invasion) as the risk of lymph node metastasis is <1% 1

Follow-up After Initial Treatment

• For suspected recurrence, consider:
  • Whole body PET/CT if not previously performed 1
  • Pelvic MRI to aid in treatment planning 1
  • CT chest, abdomen, and pelvis with IV contrast 1

The preoperative evaluation should be tailored according to tumor size, depth of invasion, and proximity to midline, with the primary goal of accurately assessing the extent of primary disease and lymph node status to guide appropriate surgical management and improve outcomes related to morbidity, mortality, and quality of life.