1. Restaging lung cancer patients after induction therapy is difficult to interpret based on radiographic methods alone due to their poor predictive value in assessing tumor response and mediastinal involvement. 2. While PET/CT may help predict tumor response, timing is important as optimal accuracy occurs around 26 days after therapy. 3. Surgical exploration remains important for confirming radiographic findings and assessing resectability given imaging limitations in evaluating response to induction therapies.

1. Restaging the Primary Tumor
Cameron Wright, MD
Thoracic Surgery
MGH
2012 Focus on Thoracic Surgery:
Lung Cancer

2. Disclosures
None

3. CT Characteristics of Locally
Advanced Disease
• Pleural effusion and nodularity-suggestive of M1a disease-
thoracentesis or VATS exploration and biopsy
• Chest wall invasion-signs of invasion include bone
destruction, pleural thickening, loss of extrapleural fat plane,
tumor extending into the chest wall and extensive contact
between chest wall and tumor. Only bone destruction is
100% accurate.
• Mediastinal invasion-invasion of mediastinal fat, extensive
contact with the mediastinal pleura (> 3 cm) or aorta (>90
degree ) suggestive of invasion. However unless there is
extensive invasion CT is often unreliable.

4. LLL Adenocarcinoma with Pleural
Metastases in Fissure
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5. NCCN Restaging Guidelines
• Restaging after induction therapy is difficult to interpret,
but CT +/- PET should be performed to exclude disease
progression or interval development of metastatic disease
• Radiographic methods have a poor positive and negative
predictive values in the evaluation of the mediastinum
after neoadjuvant therapy
• Recommendations are category 2A
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6. Comparison of Pathologic and
Radiographic Response-INT-0160
• Phase II trial of induction chemoradiotherapy for superior
sulcus tumors
• 2 cycles of cisplatin and etoposide with concurrent 45 Gy of
radiation
• 83 patients underwent thoracotomy
• 46% had a partial radiographic response, 54% stable
disease
• 34% had a pCR, 31% had microscopic residual disease,
and 35% had gross residual disease
• 35% with stable radiographic disease had a pCR!
• 38% with a partial radiographic response had a pCR!
Rusch VW et al. JTCVS 2001;121:472-83
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7. Meta Analysis-Use of PET to
Predict Tumor Response
Author Prevalence Sensitivity Specificity PPV NPV
of
Residual
Disease
Cerfolio 9% 97% 100% 100% 67%
SUV>3
Ohtsuka 80% 89%
CR>0.25
Port 24% 100% 58% 43% 100%
SUV ↓ 50%
Ryu 74% 88% 67% 88% 67%
SUV> 3
Yamamoto 88% 89% 78% 94%
SUV>4.5
Rebollo-Aguire AC et al. J Surg Oncol 2010;101:486-94.
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8. Timing of Restaging PET/CT
• Retrospective review of accuracy of PET/CT in staging
patients after induction CT/RT
• 109 patients (90% N2)
• 50% ↓ Max SUV considered to be a complete response
• ROC analysis suggested optimum time for restaging was
26 days
• PET issues-not standardized, amount FDG given,
scanning technique, glucose level, etc
Cerfolio RJ, Bryant AS. Ann Thorac Surg 2007;84:1092-7.
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9. T4N0M0 SVC Involvement before
and after Induction CT/RT
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10. T4 SVC Postinduction Pathology
• FINAL PATHOLOGIC DIAGNOSIS:
• A. RIGHT UPPER LOBE, LUNG LOBECTOMY:
• Squamous cell carcinoma. See synoptic report.
•
• B. SUPERIOR VENA CAVA, EXCISION:
• Squamous cell carcinoma invading vessel wall.
•
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11. LUL T3N1M0 Before and After CT/RT
Pre Post
Post
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12. T3N1 Postinduction Pathology
• FINAL PATHOLOGIC DIAGNOSIS:
• A. LUNG PNEUMONECTOMY, LEFT:
• Squamous cell carcinoma (4.4 cm), moderately
differentiated, s/p chemoradiation
• with approximately 30% of tumor mass showing
necrosis.
•
• Note: The tumor invades the hilar fat but the inked soft
tissue resection
• margins are free.
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13. LUL Adenocarcinoma with RLN
Involvement (T4N0M0)
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14. T4 LUL after Induction CT/RT
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15. T4 LUL Pathology
• FINAL PATHOLOGIC DIAGNOSIS:
• A. LUNG PNEUMONECTOMY, LEFT:
•
• HISTOLOGIC TYPE (modified WHO classification):
Adenocarcinoma, acinar poorly
• differentiated, two small foci of residual carcinoma
(each approximately 1 cm)
• amidst extensive necrosis secondary to therapy).
•
• TUMOR SIZE (MAXIMUM DIAMETER): 10 cm.
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16. Bottom Line
• Confirm absence disease progression and distant
metastatic disease with appropriate scans
• Review preinduction imaging for areas that lead to a
concern for a complete resection
• Review postinduction imaging to confirm absence of
progressive disease and any response to therapy,
especially in areas for concern about resectability
• Exploration is always the final common denominator and
often leads to findings that are better then what the CT
suggests
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