Radiotherapy for lung tumors arising after a prior pneumonectomy

Treatment of patients with lung tumors in the contralateral lung after a prior pneumonectomy is challenging, especially for centrally located lesions. The curative modalities have included surgery, cryoablation, radiofrequency ablation, and radiotherapy (1-5). Unfortunately, available data on curative treatment of lung tumors after pneumonectomy by these modalities are limited to small series and case reports, and the safety and efficacy of these modalities remained unclear (1-5).

With the improvement of technology, stereotactic radiotherapy could be a promising treatment for patients with lung tumors arising after a pneumonectomy. In the article by Dr. Senthi et al., 27 patients received curative radiotherapy for a second primary lung cancer arising post-pneumonectomy (6). Utilizing modern radiotherapy techniques, the authors achieved a median survival of 39 months (95% CI, 33-44 months). The 3-year actuarial risk of local recurrence and regional recurrence was 8% and 10%, respectively, which were comparable with that reported after stereotactic ablation radiotherapy for early stage primary lung cancer. Grade 3 or higher radiation pneumonitis was only noted in three patients (11%). The results are encouraging for patients with this difficult situation.

Because tissue proof of lung tumors was available only in a minority of their patients, the promising results of this study should be interpreted with some caution. The lack of histologic verification in the majority of the patients, however, is fairly reasonable for these single-lung patients owing to a significant risk of life-threatening pneumothorax after transthoracic needle biopsy (range, 20% to 50%) (7-12). Because the results suggest that stereotactic radiotherapy is safe and effective after pneumonectomy, high-risk diagnostic procedures should be avoided, and more emphasis should be placed on obtaining a diagnosis using noninvasive molecular techniques (13,14).

The authors showed that stereotactic radiotherapy is feasible even in patients with compromised cardiopulmonary function or with poor global initiative for chronic obstructive lung disease (GOLD) scores (50% of their patients had GOLD Class 3 or 4 chronic obstructive lung disease). They therefore recommend surveillance for the occurrence of second primary lung cancer in patients who are unfit for any curative surgery. Early diagnosis of a second lung cancer can be very important after pneumonectomy, because the radiation dose to the healthy part of the lung and thus, toxicity, is higher in larger tumors. Currently when treating second primary lung cancers arising post-pneumonectomy, the fractionation schedule should be considered, balancing the risks of central organ toxicity against radiation pneumonitis and utilizing less conformal plans with avoidance sectors.

This article represents the largest series describing clinical outcomes for the curative treatment of second primary lung cancer arising post-pneumonectomy. As prolonged survival can be achieved with modern radiotherapy techniques, the findings reiterate the importance of such follow-up and referral for a radiotherapy opinion. Should radiotherapy be offered, the risk of radiation pneumonitis should be acknowledged and treatment planned accordingly. In conclusion, when a second primary stage I lung cancer arises after previous pneumonectomy, the use of risk-adapted stereotactic radiotherapy is an effective and low-risk treatment even in patients with severe pulmonary dysfunction. Routine surveillance after pneumonectomy and treatment by stereotactic radiotherapy for second tumors should be considered in all such patients.

Acknowledgements

Disclosure: The authors declare no conflict of interest.

References

1. Lagerwaard FJ, Voet PW, van Meerbeeck JP, et al. Curative radiotherapy for a second primary lung cancer arising after pneumonectomy -- techniques and results. Radiother Oncol 2002;62:21-5.
2. Yamauchi Y, Izumi Y, Yashiro H, et al. Percutaneous cryoablation for pulmonary nodules in the residual lung after pneumonectomy: report of two cases. Chest 2011;140:1633-7.
3. Haasbeek CJ, Lagerwaard FJ, de Jaeger K, et al. Outcomes of stereotactic radiotherapy for a new clinical stage I lung cancer arising postpneumonectomy. Cancer 2009;115:587-94.
4. Donington JS, Miller DL, Rowland CC, et al. Subsequent pulmonary resection for bronchogenic carcinoma after pneumonectomy. Ann Thorac Surg 2002;74:154-8; discussion 158-9.
5. Terzi A, Lonardoni A, Scanagatta P, et al. Lung resection for bronchogenic carcinoma after pneumonectomy: a safe and worthwhile procedure. Eur J Cardiothorac Surg 2004;25:456-9.
6. Senthi S, Haasbeek CJ, Lagerwaard FJ, et al. Radiotherapy for a second primary lung cancer arising post-pneumonectomy: planning considerations and clinical outcomes. J Thorac Dis 2013;5:116-22.
7. Ong CL, Verbakel WF, Cuijpers JP, et al. Stereotactic radiotherapy for peripheral lung tumors: a comparison of volumetric modulated arc therapy with 3 other delivery techniques. Radiother Oncol 2010;97:437-42.
8. Geraghty PR, Kee ST, McFarlane G, et al. CT-guided transthoracic needle aspiration biopsy of pulmonary nodules: needle size and pneumothorax rate. Radiology 2003;229:475-81.
9. Cox JE, Chiles C, McManus CM, et al. Transthoracic needle aspiration biopsy: variables that affect risk of pneumothorax. Radiology 1999;212:165-8.
10. Laurent F, Michel P, Latrabe V, et al. Pneumothoraces and chest tube placement after CT-guided transthoracic lung biopsy using a coaxial technique: incidence and risk factors. AJR Am J Roentgenol 1999;172:1049-53.
11. Topal U, Ediz B. Transthoracic needle biopsy: factors effecting risk of pneumothorax. Eur J Radiol 2003;48:263-7.
12. Covey AM, Gandhi R, Brody LA, et al. Factors associated with pneumothorax and pneumothorax requiring treatment after percutaneous lung biopsy in 443 consecutive patients. J Vasc Interv Radiol 2004;15:479-83.
13. van Tinteren H, Hoekstra OS, Smit EF, et al. Effectiveness of positron emission tomography in the preoperative assessment of patients with suspected non-small-cell lung cancer: the PLUS multicentre randomised trial. Lancet 2002;359:1388-93.
14. Spira A, Beane JE, Shah V, et al. Airway epithelial gene expression in the diagnostic evaluation of smokers with suspect lung cancer. Nat Med 2007;13:361-6.