What are the current updates on the surgical management of a pediatric hepatoblastoma confined to a single liver lobe?

Surgical Management of Single-Lobe Hepatoblastoma in Pediatrics

For pediatric hepatoblastoma confined to a single liver lobe, proceed with cisplatin-based chemotherapy for 2-4 cycles, then perform complete surgical resection with negative margins if achievable; if the tumor remains unresectable despite being confined to the liver, proceed directly to primary liver transplantation rather than attempting marginal resection. 1, 2

Initial Assessment and Risk Stratification

• Apply PRETEXT staging immediately at diagnosis to determine resectability and guide early transplant referral decisions. 1, 2
• Measure serum alpha-fetoprotein (AFP) at presentation; levels >1,000 ng/dL are typical of hepatoblastoma. 2
• Obtain contrast-enhanced CT or MRI with multiphasic technique to characterize the mass, evaluate vascular involvement, and define disease extent. 2
• Perform chest CT to detect pulmonary metastases, which is essential for staging and treatment planning. 2

Standard Treatment Algorithm

Step 1: Immediate Chemotherapy Initiation

• Begin cisplatin-based chemotherapy immediately after diagnosis according to the Children's Oncology Group protocol (COG-AHEP0731). 1, 2
• Administer sodium thiosulfate (16-20 g/m²) 6 hours after each cisplatin dose to prevent ototoxicity without compromising survival outcomes in non-metastatic disease. 3

Step 2: Reassessment After 2-4 Chemotherapy Cycles

• Evaluate tumor resectability after 2-4 cycles using dynamic CT or MRI studies with modified RECIST criteria. 3

Step 3: Surgical Decision Based on Resectability

If complete resection with negative margins is achievable:

• Proceed with conventional partial hepatectomy using modern techniques including intraoperative ultrasonography for precise localization, vascular exclusion techniques, and ultrasonic dissection. 1, 4, 5
• Perform anatomic resection to ensure tumor-free margins and include any satellite lesions. 4, 6

If tumor remains unresectable but confined to the liver:

• Proceed directly to primary liver transplantation. 1, 2
• This approach achieves 82% 10-year survival compared to only 30% for "rescue" transplantation after failed resection attempts. 1, 2

Early Transplant Referral Criteria

• Refer for liver transplant evaluation at diagnosis or no later than after 2 cycles of chemotherapy if the tumor is nonmetastatic but unresectable. 1, 2

High-risk features requiring immediate transplant center involvement:

• PRETEXT IV disease (involving all four liver sectors). 1, 4
• Complex PRETEXT III disease. 1
• Centrally located tumors involving main hilar structures or main hepatic veins, making tumor-free margins unlikely. 1, 4

Management of Metastatic Disease

• Do not exclude patients with pulmonary metastases from curative intent. 1, 2
• Children with pulmonary metastases can achieve excellent outcomes when post-chemotherapy chest CT shows resolution or when residual nodules are completely resected with tumor-free margins. 1, 2
• Outcomes are comparable to non-metastatic disease when complete resection of metastases is achieved. 1

Critical Pitfalls to Avoid

• Never delay transplant referral beyond 2 chemotherapy cycles for clearly unresectable disease; this reduces survival from 82% to 30% at 10 years. 1, 2
• Avoid attempting aggressive conventional resection when positive margins are anticipated. This converts a primary transplant candidate (82% survival) into a rescue transplant candidate (30% survival). 1, 2
• Do not perform "heroic" liver resections with high probability of leaving residual tumor; primary liver transplantation should be considered instead. 4
• Do not apply adult HCC criteria (Milan criteria) to hepatoblastoma. Children with hepatoblastoma can achieve excellent outcomes with much larger tumors due to better tumor biology and chemosensitivity. 1, 2
• Avoid liver biopsy when imaging and AFP are diagnostic to prevent tumor seeding. 2

Modern Surgical Techniques

• Use intraoperative ultrasonography (IOUS) for precise tumor localization and staging, enabling anatomical resections. 4, 5
• Apply vascular exclusion techniques and ultrasonic dissection to minimize blood loss; transfusion is needed in fewer than 10% of cases with modern techniques. 5, 6
• Treatment-related mortality should be less than 1-3% with current surgical expertise. 5

Multidisciplinary Team Requirements

The management requires coordination between:

• Pediatric hepatobiliary surgeon. 2
• Liver transplant surgeon. 2
• Pediatric oncologist for chemotherapy protocols. 2
• Pediatric gastroenterologist with liver disease expertise. 2

The key distinction in modern management is recognizing that primary liver transplantation for unresectable disease yields dramatically superior outcomes (82% vs 30% 10-year survival) compared to rescue transplantation after failed resection attempts, making early and accurate assessment of resectability—and timely transplant referral—the most critical surgical decision point. 1, 2