Definitive reirradiation for locoregionally recurrent non-small cell lung cancer with proton beam therapy or intensity modulated radiation therapy: predictors of high-grade toxicity and survival outcomes

Consensus Statement on Proton Therapy in Early-Stage and Locally Advanced Non-Small Cell Lung Cancer

Radiation dose escalation has been shown to improve local control and survival in patients with non-small cell lung cancer in some studies, but randomized data have not supported this premise, possibly owing to adverse effects. Because of the physical characteristics of the Bragg peak, proton therapy (PT) delivers minimal exit dose distal to the target volume, resulting in better sparing of normal tissues in comparison to photon-based radiation therapy. This is particularly important for lung cancer given the proximity of the lung, heart, esophagus, major airways, large blood vessels, and spinal cord. However, PT is associated with more uncertainty because of the finite range of the proton beam and motion for thoracic cancers. PT is more costly than traditional photon therapy but may reduce side effects and toxicity-related hospitalization, which has its own associated cost. The cost of PT is decreasing over time because of reduced prices for the building, machine, maintenance, and overhead, as well as newer, shorter treatment programs. PT is improving rapidly as more research is performed particularly with the implementation of 4-dimensional computed tomography-based motion management and intensity modulated PT. Given these controversies, there is much debate in the oncology community about which patients with lung cancer benefit significantly from PT. The Particle Therapy Co-operative Group (PTCOG) Thoracic Subcommittee task group intends to address the issues of PT indications, advantages and limitations, cost-effectiveness, technology improvement, clinical trials, and future research directions. This consensus report can be used to guide clinical practice and indications for PT, insurance approval, and clinical or translational research directions.

Should salvage surgery be considered for local recurrence after definitive chemoradiation in locally advanced non-small cell lung cancer?

Background

Incidence of local relapse after definitive chemoradiation (>59 Gy) for locally advanced non-small-cell lung cancer (NSCLC) is high, irrespective of high dose radiation applied. Experience with salvage lung resections in patients with locally relapsed NSCLC after definitive chemoradiation is limited. We present our series of salvage lung resections for local NSCLC relapse after curative–intent chemoradiation for locally advanced tumor.

Methods

Nine consecutive patients with local tumor recurrence or persistence following definitive chemoradiation were reviewed. Kaplan-Meier analysis was used to assess patient survival.

Results

All patients received definitive radiation (median dose 66.2 Gy) with concurrent chemotherapy. Tumor stage prior to chemoradiation was IIIA in 8 patients and IV in 1. In 4 patients tumor invaded the chest wall, in 2 the spine and in 1 the aorta. Median interval between chemoradiation and salvage resection was 30.2 weeks. Nine patients underwent 9 resections (6 lobectomies, 1 bilobectomy, 1 pneumonectomy and 1 bi-segmentectomy). One death occurred on the 12th postoperative day. Median overall survival was 23 months; postoperative 3-year survival was 47 %. Median progression-free survival was 21 months.

Conclusion

Salvage lung resection for locally recurrent or persisted NSCLC in selected patients with locally advanced NSCLC following definitive chemoradiation is a worthwhile treatment option.

Proton Beam Therapy for Non-Small Cell Lung Cancer: Current Clinical Evidence and Future Directions

Lung cancer is the leading cancer cause of death in the United States. Radiotherapy is an essential component of the definitive treatment of early-stage and locally-advanced lung cancer, and the palliative treatment of metastatic lung cancer. Proton beam therapy (PBT), through its characteristic Bragg peak, has the potential to decrease the toxicity of radiotherapy, and, subsequently improve the therapeutic ratio. Herein, we provide a primer on the physics of proton beam therapy for lung cancer, present the existing data in early-stage and locally-advanced non-small cell lung cancer (NSCLC), as well as in special situations such as re-irradiation and post-operative radiation therapy. We then present the technical challenges, such as anatomic changes and motion management, and future directions for PBT in lung cancer, including pencil beam scanning.

Salvage stereotactic body radiotherapy for locally recurrent non-small cell lung cancer after sublobar resection and i(125) vicryl mesh brachytherapy

Purpose

Locally recurrent non-small cell lung cancer (LR-NSCLC) remains challenging to treat, particularly in patients having received prior radiotherapy. Heterogeneous populations and varied treatment intent in existing literature result in significant limitations in evaluating efficacy of lung re-irradiation. In order to better establish the impact of re-irradiation in patients with LR-NSCLC following high-dose radiotherapy, we report outcomes for patients treated with prior sublobar resection and brachytherapy that subsequently underwent stereotactic body radiotherapy (SBRT).

Methods

A retrospective review of patients initially treated with sublobar resection and I¹²⁵ vicryl mesh brachytherapy, who later developed LR-NSCLC along the suture line, was performed. Patients received salvage SBRT with curative intent. Dose and fractionation were based on tumor location and size, with a median prescription dose of 48 Gy in 4 fractions (range 20–60 Gy in 1–4 fractions).

Results

Thirteen consecutive patients were identified with median follow-up of 2.1 years (range 0.7–5.6 years). Two in-field local failures occurred at 7.5 and 11.1 months, resulting in 2-year local control of 83.9% (95% CI, 63.5–100.0%). Two-year disease-free survival and overall survival estimates were 38.5% (95% CI, 0.0–65.0%) and 65.8% (95% CI, 38.2–93.4%). Four patients (31%) remained disease-free at last follow-up. All but one patient who experienced disease recurrence developed isolated or synchronous distant metastases. Only one patient (7.7%) developed grade ≥3 toxicity, consisting of grade 3 esophageal stricture following a centrally located recurrence previously treated with radiofrequency ablation.

Conclusion

Despite high-local radiation doses delivered to lung parenchyma previously with I¹²⁵ brachytherapy, re-irradiation with SBRT for LR-NSCLC results in excellent local control with limited morbidity, allowing for potential disease cure in a subset of patients.

Accelerated radiotherapy and concurrent chemotherapy for patients with contralateral central or mediastinal lung cancer relapse after pneumonectomy

BACKGROUND

Treatment options are very limited for patients with lung cancer who experience contralateral central or mediastinal relapse following pneumonectomy. We present results of an accelerated salvage chemoradiotherapy regimen.

METHODS

Patients with localized contralateral central intrapulmonary or mediastinal relapse after pneumonectomy were offered combined chemoradiotherapy including concurrent weekly cisplatin (25 mg/m(2)) and accelerated radiotherapy [accelerated fractionated (AF), 60 Gy, 8×2 Gy per week] to reduce time for repopulation. Based on 4D-CT-planning, patients were irradiated using multifield intensity-modulated radiotherapy (IMRT) or helical tomotherapy.

RESULTS

Between 10/2011 and 12/2012, seven patients were treated. Initial stages were IIB/IIIA/IIIB: 3/1/3; histopathological subtypes scc/adeno/large cell: 4/1/2. Tumour relapses were located in mediastinal nodal stations in five patients with endobronchial tumour in three patients. The remaining patients had contralateral central tumour relapses. All patients received 60 Gy (AF), six patients received concurrent chemotherapy. Median dose to the remaining contralateral lung, esophagus, and spinal cord was 6.8 (3.3-11.4), 8.0 (5.1-15.5), and 7.6 (2.8-31.2) Gy, respectively. With a median follow-up of 29 [17-32] months, no esophageal or pulmonary toxicity exceeding grade 2 [Common terminology criteria for adverse events (CTC-AE) v. 3] was observed. Median survival was 17.2 months, local in-field control at 12 months 80%. Only two local recurrences were observed, both in combination with out-field metastases.

CONCLUSIONS

This intensified accelerated chemoradiotherapy schedule was safely applicable and offers a curative chance in these pretreated frail lung cancer patients.

Special topics in immunotherapy and radiation therapy: reirradiation and palliation

Immunotherapy has revolutionized the treatment of non-small cell lung cancer (NSCLC). However, thus far, its use has only been established in patients with advanced disease either as first-line therapy in selected patients or following chemotherapy. What is not yet known is how best to incorporate radiation with immunotherapy agents. Many patients with advanced disease can benefit from palliative radiation, but the combination of radiation with immunotherapy has the potential to increase the toxicity of both modalities. Intriguingly, the combination also has the potential to enhance the efficacy of both modalities. For this reason, combining immunotherapy and radiation may help salvage patients with recurrent localized disease who are candidates for re-irradiation. We review the current data evaluating immunotherapy with both palliative radiation as well as definitive re-irradiation in NSCLC.