Phase I study of accelerated conformal radiotherapy for stage I non-small-cell lung cancer in patients with pulmonary dysfunction: CALGB 39904

An optimal dose-fractionation for stereotactic body radiotherapy in peripherally, centrally and ultracentrally located early-stage non-small lung cancer

Stereotactic body radiotherapy (SBRT), also known as stereotactic ablative radiotherapy (SABR), is commonly used in inoperable patients with early-stage non-small lung cancer (NSCLC). This treatment has good outcomes and low toxicity in peripherally located tumors. However, in lesions which are located close to structures such as the bronchial tree or mediastinum the risk of severe toxicity increases. This review summarizes the evidence of dose-fractionation in SBRT of NSCLC patients in various locations.

Hypofractionated Volumetric-Modulated Arc Radiotherapy for Patients With Non-Small-Cell Lung Cancer Not Suitable for Surgery or Conventional Chemoradiotherapy or SBRT

Background

Hypofractionated radiotherapy (HypoRT) has been used to pursue an alternative treatment regimen for patients with non-small-cell lung cancer (NSCLC) who are not eligible for stereotactic ablative radiotherapy (SABR), surgery or concurrent chemoradiotherapy (CCRT) and has shown good local control and safety. We analyzed the feasibility of using volumetric-modulated arc radiotherapy (VMAT) with the simultaneous integrated boost (SIB) technique to achieve high local control with few treatment-related toxicities.

Patients and Methods

A total of 55 patients with stage I-IV NSCLC who were not candidates for SABR, surgery or CCRT were included in the present study. All patients received a prescribed dose of 60 to 66 Gy in 15 fractions. Local progression-free survival (LPFS), PFS, overall survival (OS), and toxicities were retrospectively analyzed.

Results

Thirty-three patients (60.0%) had stage IV or recurrent disease in this study. The median follow-up time was 8 months (interquartile range: 5.0-16.3 months). The 1-year and 2-year OS rates were 84.3% and 69.9%, and the 1-year and 2-year LPFS rates were 91.0% and 63.0%. The median OS (mOS) and median LPFS (mLPFS) were not reached, and median PFS (mPFS) was 15 months. Twenty-eight (51.9%) patients had disease progression at the time of analysis. Of these, 7 (13.0%), 7 (13.0%) and 21 (38.9%) had local recurrence, locoregional failure and distant metastasis, respectively. All cases of local recurrence were found within the SIB region. Four patients had grade 2-3 pneumonitis, and 8 patients had grade 2-3 esophagitis. Patients with grade 2-3 esophagitis had significantly higher maximum dose and dose to 5 cm³ volume to esophagus than those with grade 0-1 esophagitis. No grade 4 or higher toxicity was observed.

Conclusion

The 60 to 66 Gy in 15 fractions RT regimen provides favorable local control and survival with well-tolerated toxicities. Hypofractionated VMAT+SIB is an alternative treatment option for patients with NSCLC who cannot tolerate standard definitive therapy.

Long-Term Outcomes From a Phase 2 Trial of Radiofrequency Ablation Combined With External Beam Radiation Therapy for Patients With Inoperable Non-Small Cell Lung Cancer

PURPOSE

Long-term outcomes after external beam radiation therapy (EBRT) and radiofrequency ablation (RFA) for medically inoperable early-stage non-small cell lung cancer (NSCLC) are not well known.

METHODS AND MATERIALS

Patients with medically inoperable early-stage NSCLC were enrolled in a prospective single-arm, phase 2 study between June 2007 and October 2008 and were treated with RFA followed by EBRT. Radiation was delivered using hypofractionated radiation therapy (HFRT; 70.2 Gy in 26 fractions) or stereotactic body radiation therapy (54 Gy in 3 fractions).

RESULTS

Twelve patients were evaluable; 10 patients were treated with HFRT. The cumulative incidence of local progression at 5 years was 16.7% (95% confidence interval [CI], 0-37.8). Median progression-free survival was 37.8 months (95% CI, 11.1 to not reached) and median overall survival was 53.6 months (95% CI, 21.0 to not reached). There were no mortalities within 30 days after RFA and no grade ≥4 toxicity.

CONCLUSIONS

The combination of RFA with EBRT appears feasible with favorable long-term local control. However, because SBRT alone has similar or better rates of control, we do not recommend routine combined RFA and EBRT.

Hypofractionation in Early Stage Non-Small Cell Lung Cancer

Radiation treatment of early stage nonsmall cell lung cancer has evolved over the past 2 decades to progressively more hypofractionated treatment courses. Results comparable to surgical resection are seen with stereotactic body radiotherapy, which is now the standard of care for medically inoperable patients, and a treatment option for operable patients as well. Understanding of the optimal radiation dose and fractionation are evolving, especially for central tumors which have higher treatment toxicity than peripheral tumors.

Five- Versus Ten-Fraction Regimens of Stereotactic Body Radiation Therapy for Primary and Metastatic NSCLC

INTRODUCTION

At our institution, stereotactic body radiotherapy (SBRT) has commonly been prescribed with 50 Gy in 5 fractions and in select cases, 50 Gy in 10 fractions. We sought to evaluate the impact of these 2 fractionation schedules on local control and survival outcomes.

METHODS

We reviewed patients treated with SBRT with 50 Gy/5 fraction or 50 Gy/10 fraction for early-stage non-small cell lung cancer (NSCLC) and metastatic NSCLC. Cumulative incidence of local failure (LF) was estimated using competing risk methodology. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method only for patients with stage I disease.

RESULTS

Of the 353 lesions, 300 (85%) were treated with 50 Gy in 5 fractions and 53 (15%) with 10 fractions. LFs at 3 years were 6.5% and 23.9% and Kaplan-Meier estimate of median time to LF was 17.5 months and 26.2 months, respectively. Multivariable analysis revealed increasing planning target volume (hazard ratio 1.01, P = .04) as an independent predictor of increased LF, but tumor size, ultracentral location, and 10 fractions were not. Among patients with stage I NSCLC (n = 298), overall median PFS was 35.6 months and median OS was 42.4 months. There was no difference in PFS or OS between the 2 treatment regimens for patients with stage I NSCLC. Low rates of grade 3+ toxicity were observed, with 1 patient experiencing grade 3 pneumonitis after a 5-fraction regimen of SBRT.

CONCLUSION

Dose-fractionation schemes with BED₁₀ ≥ 100 Gy provide superior local control and should be offered when meeting commonly accepted constraints. If those regimens appear unsafe, 50 Gy in 10 fractions may provide acceptable compromise between tumor control and safety with relatively durable control, and minimal negative impact on long-term survival.

Oncologic Outcomes of Surgery Versus SBRT for Non-Small-Cell Lung Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The optimal treatment of stage I non-small-cell lung carcinoma is subject to debate. The aim of this study was to compare overall survival and oncologic outcomes of lobar resection (LR), sublobar resection (SR), and stereotactic body radiotherapy (SBRT).

METHODS

A systematic review and meta-analysis of oncologic outcomes of propensity matched comparative and noncomparative cohort studies was performed. Outcomes of interest were overall survival and disease-free survival. The inverse variance method and the random-effects method for meta-analysis were utilized to assess the pooled estimates.

RESULTS

A total of 100 studies with patients treated for clinical stage I non-small-cell lung carcinoma were included. Long-term overall and disease-free survival after LR was superior over SBRT in all comparisons, and for most comparisons, SR was superior to SBRT. Noncomparative studies showed superior long-term overall and disease-free survival for both LR and SR over SBRT. Although the papers were heterogeneous and of low quality, results remained essentially the same throughout a large number of stratifications and sensitivity analyses.

CONCLUSION

Results of this systematic review and meta-analysis showed that LR has superior outcomes compared to SBRT for cI non-small-cell lung carcinoma. New trials are underway evaluating long-term results of SBRT in potentially operable patients.

Moderately Hypofractionated Radiotherapy Alone for Stage I-IIB Non-small Cell Lung Cancer

INTRODUCTION

The optimal management of patients with early non-small cell lung cancer (NSCLC) not amenable to surgical resection or stereotactic body radiotherapy (SBRT) or those with hilar nodal involvement ineligible for surgery or concurrent chemoradiotherapy is unclear. This report describes survival outcomes and toxicity profiles of patients treated with hypofractionated radiotherapy (HRT) alone.

METHODS

A total of 52 patients with Stage I-IIB NSCLC treated with HRT alone between 2010-2018 were reviewed. Patients were categorized as having ultracentral tumors if the planning target volume contacted or overlapped the proximal bronchial tree, esophagus, pulmonary vein or artery. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and the competing risk cumulative incidence of locoregional failure (LRF) and distant failure (DF) were estimated using death without failure as a competing risk. Pneumonitis and esophagitis rates were evaluated as per Acute Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.

RESULTS

Of the 52 patients analyzed, 50 patients were treated with radiotherapy alone to a dose of 70.2 Gy in 26 fractions, one patient was treated with 68 Gy in 25 fractions and one patient was treated with 65 Gy in 26 fractions. The median age was 72 (range 48-89), 42% of patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 2-3, 46% were stage I and 54% were stage II. Hilar nodal involvement was present in 21% of patients and 74% of node-negative patients had ultracentral primary tumors. Median OS was 39.6 months and the median PFS was 21.0 months. Overall three-year cumulative incidence of LRF and DF were 32% and 34%, respectively. Grade 3 pneumonitis occurred in two (4%) patients. No grade 3+ acute esophagitis or grade 4-5 toxicities were observed.

CONCLUSION

Hypofractionated thoracic radiotherapy consisting of 70.2 Gy is well-tolerated and results in favorable locoregional control for stage I-IIB patients who are not candidates for SBRT, surgery, or concurrent chemoradiotherapy.

Phase II study of compensator-based non-coplanar intensity-modulated radiotherapy for Stage I non-small-cell lung cancer

We conducted a Phase II study to evaluate the usefulness of compensator-based non-coplanar intensity-modulated radiotherapy (ncIMRT) for patients with surgically inaccessible Stage I non-small-cell lung cancer (NSCLC). Patients with pathologically proven or clinically diagnosed surgically inaccessible Stage I NSCLC were enrolled in this study from May 2011 to April 2014. These patients underwent ncIMRT of 75 Gy in 30 fractions regardless of the tumor location. The primary end point was 3-year overall survival, and the secondary end points were local control rate and treatment-related toxicities. A total of 48 patients (50 tumors) were enrolled in this study. Of the 50 tumors, the Stage T1 to T2 ratio was 31 to 19, and the ratio of tumors located in the central to peripheral areas was 11 to 39. During the median follow-up time of 35.9 months, the 3-year actuarial local progression-free and overall survival rates were 82.6% and 87.1%, respectively. No patients experienced toxicities of Grade 3 or greater. Standard-fractionated ncIMRT was effective and safe for patients with surgically inaccessible stage I NSCLC, regardless of the tumor location.

Accelerated Hypofractionated Radiotherapy Versus Stereotactic Body Radiotherapy for the Treatment of Stage I Nonsmall Cell Lung Cancer-A Single Institution Experience With Long-Term Follow-Up

Purpose:

Although stereotactic body radiation therapy is one of the standard treatments for stage I nonsmall cell lung cancer, in the case of central tumors it carries the risk of severe adverse events for serial organs. Accelerated hypofractionated radiotherapy is considered a reasonable alternative to treat central tumors. We have been treating central tumors with accelerated hypofractionated radiotherapy using a 75 Gy/25 fr/5 weeks regimen, and we compared the results with those of stereotactic body radiation therapy using 48 Gy/4 fr/1 week.

Methods:

Patients with central tumors and/or unfit for 1-hour fixation were candidates for accelerated hypofractionated radiotherapy. Based on the proximity to the biologically effective dose at 10 Gy, above accelerated hypofractionated radiotherapy regimen was adopted.

Results:

From October 2003 to December 2010, 159 patients, who received either accelerated hypofractionated radiotherapy (103 cases) or stereotactic body radiation therapy (56 cases), were included in the analysis. In the accelerated hypofractionated radiotherapy group, 40 (39%) cases were central tumors, whereas all cases were peripheral tumors in the stereotactic body radiation therapy group. Overall 5-year local control and survival rates were 81.9% (95% confidence interval 73.6%-90.1%) and 46.5% (95% confidence interval 36.7%-56.2%), respectively for the accelerated hypofractionated radiotherapy group, and 75.4% (95% confidence interval 63.0%-87.8%) and 44.6% (95% confidence interval 31.6%-57.7%), respectively for the stereotactic body radiation therapy group (n.s.). Among central tumors, ultracentral tumors (21 cases) and the remaining central tumors (19 cases) were similar in both local control and survival. On multivariate analysis, hazard ratios for accelerated hypofractionated radiotherapy versus stereotactic body radiation therapy were <1 for both local control and survival. Pulmonary toxicity was similar in both groups. No serial organ toxicity was observed for central tumors.

Conclusions:

Accelerated hypofractionated radiotherapy with a 75 Gy/25 fr/5 weeks regimen is promising in that it can obtain similar local control and survival results to stereotactic body radiation therapy, and it can control both central and peripheral tumors without any serial organ toxicities. Based on these results, prospective multicenter trials are worth conducting, especially for ultracentral tumors.

Tumor Control and Toxicity after SBRT for Ultracentral, Central, and Paramediastinal Lung Tumors

PURPOSE

Increased rates of toxicity have been described after stereotactic body radiation therapy (SBRT) for central lung tumors within 2 cm of the proximal bronchial tree (PBT). Recent studies have defined a new class of ultracentral tumors. We report our experience treating ultracentral, central, and paramediastinal tumors with SBRT and compare toxicity, disease control, and survival rates.

METHODS AND MATERIALS

We reviewed the records of patients with central lung tumors treated with SBRT between September 2009 and July 2017. Tumors were classified as central if within 2 cm of the PBT, ultracentral if the planning target volume touched the PBT or esophagus, and paramediastinal if touching mediastinal pleura. Actuarial rates of grades 2+ and 3+ toxicity, local control (LC), and overall survival were assessed using the Kaplan-Meier method and compared using a log-rank test. Toxicity was scored with the Common Terminology Criteria for Adverse Events, version 4.03.

RESULTS

We identified 68 patients with 69 central lung tumors, including 14 ultracentral, 15 paramediastinal, and 39 central tumors. Fifty-three patients were treated for early stage lung cancer and 15 for lung metastases. The prescribed dose ranged from 40 Gy to 60 Gy over 3 to 8 fractions. Most patients were treated using 5 fractions (83%), followed by 8 fractions (10%). Median follow-up was 19.7 months (range, 3.3-78.3 months). The 2-year estimates of LC (89%, 85%, and 93%, respectively; P = .72) and overall survival (76%, 73%, and 72%, respectively; P = .75) for ultracentral, central, and paramediastinal tumors were similar. Ultracentral tumors had an increased risk of grade 2+ toxicity (57.6% vs 14.2% vs 7.1%; P = .007) at 2 years. One patient with an ultracentral tumor developed grade 5 respiratory failure.

CONCLUSIONS

The oncologic outcomes after SBRT for ultracentral, central, and paramediastinal lung tumors were similar, with LC exceeding 85% at 2 years using predominantly 5-fraction schedules. Ultracentral lung tumors were associated with an increased risk of toxicity in our patient cohort. Additional studies are needed to minimize toxicity for ultracentral tumors.

Phase 1 Study of Accelerated Hypofractionated Radiation Therapy With Concurrent Chemotherapy for Stage III Non-Small Cell Lung Cancer: CALGB 31102 (Alliance)

PURPOSE

To investigate the safety of accelerated hypofractionated radiation therapy (AHRT) with concurrent chemotherapy (CT) for inoperable stage III non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The primary objectives were to define the maximally tolerable course of accelerated radiation therapy and to describe toxicities of therapy. Total radiation therapy remained at 60 Gy. The number of once-daily fractions in each successive cohort was reduced as follows: cohort 1, 60 Gy in 27 fractions; cohort 2, 60 Gy in 24 fractions; cohort 3, 60 Gy in 22 fractions; and cohort 4, 60 Gy in 20 fractions. Concurrent treatment consisted of weekly carboplatin area under the curve (AUC) 2 and paclitaxel 45 mg/m². Consolidation treatment consisted of carboplatin AUC 6 and paclitaxel 200 mg/m² every weeks × 2 cycles. Maximum tolerated dose: Of 6 patients/cohort, ≤2 patients experienced grade ≥3 toxicity, and ≤1 patient experienced grade ≥4 toxicity.

RESULTS

22 patients were accrued; of those, 21 patients were evaluable between July 2012 and May 2014. Grade 5 toxicity occurred in 3 patients: 1 patient in cohort 2 (hemoptysis), 2 patients in cohort 3 (hemoptysis, pneumonitis). The maximum tolerated dose (MTD) was defined by cohort 2 (60 Gy in 2.5 Gy/fraction). Time to grade 5 toxicity was 9 months, 6 months, and 9 months after the start of treatment. The median follow-up time was 23.0 months (range, 7.6-30.6 months) in living patients, the median overall survival was 19.3 months (95% confidence interval [CI] 9.3-34.0 months), and the median progression-free survival was 12.2 months (95% CI 6.1-22.5 months).

CONCLUSIONS

Only modest hypofractionation was achievable as a result of long-term toxicities. Nevertheless, the MTD of 60 Gy given at 2.5 Gy/fraction allows completion of RT in 20% fewer treatments than conventional therapy. Further investigation of AHRT may help to better define the therapeutic index.

Adoption of Stereotactic Body Radiotherapy for Stage IA Non-Small Cell Lung Cancer Across the United States

BACKGROUND

Stereotactic body radiotherapy (SBRT) is a treatment option for stage I non-small cell lung cancer (NSCLC), providing a potentially curative therapy for patients who are nonsurgical candidates. This study describes the adoption of SBRT vs other treatment options across the United States, as well as commonly used dose-fractionation regimens.

METHODS

We analyzed patients in the National Cancer Data Base. A total of 107 233 stage IA NSCLC patients diagnosed from 2008 to 2013 were included. We described the proportions of patients who received different surgical and radiation treatment options by year. A multivariable model was constructed to assess factors associated with patients receiving SBRT. In patients who received SBRT, we described the proportion of patients who received common dose/fractionation regimens.

RESULTS

Use of SBRT increased from 6.7% to 16.3% from 2008 to 2013, with a corresponding decrease in lobectomy/pneumonectomy (49.5% to 43.7%). The rates of wedge resection, conventional radiotherapy, and no treatment remained relatively constant. Adoption of SBRT was lowest in small community centers (8.6% of patients by 2013). On multivariable analysis, older age and treatment at larger centers were associated with higher SBRT receipt, and black race and higher comorbidity were associated with lower SBRT receipt. There was statistically significant geographic variation. Common SBRT schemes were 10 Gy × 5 (19%), 18-20 Gy × 3 (31%), and 12 Gy × 4 (16%).

CONCLUSIONS

SBRT adoption has been modest over time and has not substantially replaced less curative treatments. Lack of access to this technology in smaller cancer centers may have partly contributed to the slow adoption.

Dose-escalated Hypofractionated Intensity-modulated Radiation Therapy With Concurrent Chemotherapy for Inoperable or Unresectable Non-Small Cell Lung Cancer

PURPOSE

The local control of inoperable non-small cell lung cancer (NSCLC) using standard radiotherapy (RT) doses is inadequate. Dose escalation is a potential strategy to improve the local control for patients with NSCLC; however, the optimal dose required for local control in this setting is unknown.

METHODS AND MATERIALS

Patients with unresectable or inoperable stage II/III NSCLC with ECOG≤1 received 48 Gy in 20 daily fractions using intensity-modulated radiotherapy, followed by 1 of 3 boost dose levels: 16.8 Gy/7 (cumulative 2 Gy equivalent dose [EQD2]≅76 Gy/38), 20.0 Gy/7 (EQD2≅84 Gy/42), and 22.7 Gy/7 (EQD2≅92 Gy/46). Two cycles of cisplatin/etoposide chemotherapy were given concurrent with RT. The maximum tolerated dose was defined as the dose at which ≥30% experienced dose-limiting toxicity (any NCIC Common Terminology for Adverse Events V3.0 grade 3 or higher acute toxicity).

RESULTS

Twelve patients completed treatment with a median follow-up of 22 months (range, 7 to 48). The median age was 72 (range, 54 to 80) and 50% of patients had adenocarcinoma. Five, 3, and 4 patients were treated on dose levels 1, 2, and 3, respectively. No dose-limiting toxicity was observed. One-year local progression-free survival and overall survival estimates were 81% and 58%, respectively.

CONCLUSIONS

Hypofractionated intensity-modulated radiotherapy was well tolerated and provided meaningful local control for patients with locally advanced inoperable NSCLC. The maximum tolerated dose of RT in this setting lies beyond an EQD2 of 92 Gy/46 and further dose escalation in this setting is warranted.

Management of Patients With Stage I Lung Cancer

The treatment of stage I non–small-cell lung cancer has advanced markedly over the past century. The transition from therapeutic nihilism with ensured mortality to radical surgery with pneumonectomy to rational oncologic-based resection has resulted in dramatically improved outcomes and reduced morbidity. The superiority of anatomic resection with lobectomy over sublobar resection for fit patients with stage I disease, where more than one half of all patients should expect to be cured, is backed by level 1 evidence. Minimally invasive approaches have further decreased morbidity and mortality, and prospective trials continue to assess whether sublobar resection is appropriate in more select circumstances for tumors < 2 cm. Interest in studying the patient at high risk for complications after lobectomy has been spurred by recent advances in surgical, radiotherapy, and ablative treatment options. In particular, provocative results with stereotactic body radiotherapy have led to rapid adoption in clinical practice with a resultant decrease in the number of untreated patients. A comparison of outcomes across studies of competing modalities remains challenging given the potential impact of selection bias in single-arm trials, and attempts to conduct randomized studies have been largely unsuccessful. Given the uncertainty in defining optimal therapy, patients are best served by a multidisciplinary team of thoracic surgeons, radiation oncologists, pulmonologists, and chest and interventional radiologists to ensure that they receive the evaluation and treatment best suited not only to their tumor and medical challenges but also to their concerns, fears, and values.

Management of stage I and II nonsmall cell lung cancer

The incidence of stage I and II nonsmall cell lung cancer is likely to increase with the ageing population and introduction of screening for high-risk individuals. Optimal management requires multidisciplinary collaboration. Local treatments include surgery and radiotherapy and these are currently combined with (neo)adjuvant chemotherapy in specific cases to improve long-term outcome. Targeted therapies and immunotherapy may also become important therapeutic modalities in this patient group. For resectable disease in patients with low cardiopulmonary risk, complete surgical resection with lobectomy remains the gold standard. Minimally invasive techniques, conservative and sublobar resections are suitable for a subset of patients. Data are emerging that radiotherapy, especially stereotactic body radiation therapy, is a valid alternative in compromised patients who are high-risk candidates for surgery. Whether this is also true for good surgical candidates remains to be evaluated in randomised trials. In specific subgroups adjuvant chemotherapy has been shown to prolong survival; however, patient selection remains important. Neoadjuvant chemotherapy may yield similar results as adjuvant chemotherapy. The role of targeted therapies and immunotherapy in early stage nonsmall cell lung cancer has not yet been determined and results of randomised trials are awaited.

Hypofractionated 3D radiotherapy for inoperable T1-3 N0-1 non-small-cell lung cancer

OBJECTIVE

This study assessed the toxicity and clinical outcomes of three-dimensional (3D) hypofractionated radiotherapy (HFRT) for medically inoperable T1-3 N0-1 non-small-cell lung cancer (NSCLC).

METHODS

34 patients with inoperable early-stage NSCLC were treated from August 2008 to April 2013. Prior to enrolment, patients were required to be evaluated by an experienced thoracic surgeon to determine the "operability". All received 57 Gy in 19 fractions followed by escalated doses of 3-Gy fractions, up to a total dose of 66 Gy using a 3D conformal technique. Toxicities were measured using the Common Terminology Criteria for Adverse Effects v. 4.0.

RESULTS

The median follow-up was 33 months (7-74 months). Toxicity grades ≥3 were not observed. Local control (LC) was 80.4% at 2 years, whereas regional control (RC) was 78%. The overall survival (OS), time to progression (TTP) and time to distant metastasis (TTM) at 2 years were 60%, 59% and 80%, respectively. For patients with T1-2 N0 and a tumour size <45 mm (n = 19), rates of OS, TTP and TTM at 2 years were 71%, 75% and 94%, respectively. LC and RC at 2 years were 85% and 94%, respectively.

CONCLUSION

HFRT using 3.0-Gy fractions amounting to a total dose of 66 Gy is the recommended dose. A Phase 2 trial is warranted in order to assess the safety and efficacy of this fractionation scheme.

ADVANCES IN KNOWLEDGE

HFRT results in a favourable outcome in early-stage lung cancer without the usual restrictions in tumour size and/or location associated with previous treatment methods. No special equipment is required, therefore permitting its application in any centre.

Radiation Therapy Alone in cT1-3N0 Non-small Cell Lung Cancer Patients Who Are Unfit for Surgical Resection or Stereotactic Radiation Therapy: Comparison of Risk-Adaptive Dose Schedules

PURPOSE

High dose definitive radiation therapy (RT) alone is recommended to patients with cT1-3N0 non-small cell lung cancer, who are unfit for surgery or stereotactic RT. This study was conducted to evaluate the clinical outcomes and cost-effectiveness following RT alone using two different modest hypofractionation dose schemes.

MATERIALS AND METHODS

Between 2001 and 2014, 124 patients underwent RT alone. From 2001 till 2010, 60 Gy in 20 fractions was delivered to 79 patients (group 1). Since 2011, 60 Gy in 20 fractions (group 2, 20 patients), and 60 Gy in 15 fractions (group 3, 25 patients) were selectively chosen depending on estimated risk of esophagitis.

RESULTS

At follow-up of 16.7 months, 2-year rates of local control, progression-free survival, and overall survival were 62.6%, 39.1%, and 59.1%, respectively. Overall survival was significantly better in group 3 (p=0.002). In multivariate analyses, cT3 was the most powerful adverse factor affecting clinical outcomes. Incidence and severity of radiation pneumonitis were not different among groups, while no patients developed grade 2 esophagitis in group 3 (p=0.003). Under current Korean Health Insurance Policy, RT cost per person was 22.5% less in group 3 compared with others.

CONCLUSION

The current study demonstrated that 60 Gy in 15 fractions instead of 60 Gy in 20 fractions resulted in comparable clinical outcomes with excellent safety, direct cost saving, and improved convenience to the patients with tumors located at ≥ 1.5 cm from the esophagus.

Disparities in treatment of patients with inoperable stage I non-small cell lung cancer: a population-based analysis

BACKGROUND

Patients unable to receive surgery for stage I non-small cell lung cancer (NSCLC) can undergo conventional radiotherapy (ConvRT), stereotactic body radiotherapy (SBRT), or no treatment (NoTx). This study assessed patterns of care and disparities in the receipt of each of these treatments.

METHODS

The study included patients in the National Cancer Database from 2003 to 2011 with T1-T2N0M0 inoperable lung cancer (n = 39,822). Logistic regressions were performed to determine predictors of receiving any radiation versus NoTx and for receiving SBRT versus ConvRT.

RESULTS

Treatment with radiation was significantly less likely in blacks (odds ratio, OR 0.65) and Hispanics (OR 0.42) compared with whites. Treatment with SBRT versus ConvRT was more likely in an academic research program (OR 2.62) and a high-volume facility (OR 7.00) compared with community cancer programs or low-volume facilities. In 2011, use of SBRT, ConvRT, and NoTx was 25%, 28%, and 46% for patients in a community cancer center versus 68%, 11%, and 21%, respectively, in an academic center (p < 0.0001).

CONCLUSION

There were marked institutional and socioeconomic variations in the treatment of inoperable stage I NSCLC. These results suggest that removal of barriers to receive radiation therapy and particularly improved access to SBRT may meaningfully improve survival in this disease.

Validation of survival prognostic models for non-small-cell lung cancer in stage- and age-specific groups

PURPOSE

Prognostic models have been proposed to predict survival for non-small-cell lung cancer (NSCLC). It is important to evaluate whether these models perform better than performance status (PS) alone in stage- and age-specific subgroups.

PATIENTS AND METHODS

The validation cohort included 2060 stage I and 1611 stage IV NSCLC patients from 23CALGB studies. For stage I, Blanchon (B), Chansky (C) and Gail (G) models were evaluated along with the PS only model. For stage IV, Blanchon (B) and Mandrekar (M) models were compared with the PS only model. The c-index was used to assess the concordance between survival and risk scores. The c-index difference (c-difference) and the integrated discrimination improvement (IDI) were used to determine the improvement of these models over the PS only model.

RESULTS

For stage I, B and PS have better survival separation. The c-index for B, PS, C and G are 0.61, 0.58, 0.57 and 0.52, respectively, and B performs significantly better than PS with c-difference=0.034. For stage IV, B, M and PS have c-index 0.61, 0.64 and 0.60, respectively; B and M perform significantly better than PS with c-difference=0.015 and 0.033, respectively.

CONCLUSION

Although some prognostic models have better concordance with survival than the PS only model, the absolute improvement is small. More accurate prognostic models should be developed; the inclusion of tumor genetic variants may improve prognostic models.

Triaging early-stage lung cancer patients into non-surgical pathways: who, when, and what?

More lung cancer patients are being diagnosed at an earlier stage due to improved diagnostic imaging techniques, a trend that is expected to accelerate with the dissemination of lung cancer screening. Surgical resection has always been considered the standard treatment for patients with early-stage non-small cell lung cancer (NSCLC). However, non-surgical treatment options for patients with early-stage NSCLC have evolved significantly over the past decade with many new and exciting alternative treatments now available. These alternative treatments include radiofrequency ablation (RFA), microwave ablation (MWA), percutaneous cryoablation therapy (PCT), photodynamic therapy (PDT) and external beam radiation therapy (EBRT), including stereotactic body radiation therapy (SBRT) and accelerated hypofractionated radiation therapy. We describe the established alternatives to surgical resection, their advantages and disadvantages, potential complications and efficacy. We then describe the optimal treatment approach for patients with early-stage NSCLC based on tumor operability, size and location. Finally, we discuss future directions and whether any alternative therapies will challenge surgical resection as the treatment of choice for patients with operable early-stage lung cancer.

Additional data in the debate on stage I non-small cell lung cancer: surgery versus stereotactic ablative radiotherapy

Lobectomy has been the standard of care for patients with early stage non-small cell lung cancer (NSCLC), resulting in nearly universal local control and excellent overall survival. However, up to one-quarter of early stage patients are unable to undergo or refuse definitive resection. With the increasing adoption of stereotactic ablative radiotherapy (SABR) over conventionally fractionated radiotherapy among medical inoperable patients, tumor control and overall survival rates in this population have significantly improved. Trials demonstrating excellent outcomes among both medically inoperable and medical operable patients with stage I NSCLC have spurred interest in comparisons between surgery and SABR. The recent publication of the randomized STARS and ROSEL trials demonstrated fewer toxicities and an improvement in overall survival among patients treated with SABR compared with surgery. Based on these trials and retrospective comparisons between the modalities, definitive SABR now more firmly appears to be a viable first-line option for treating patients with operable stage I NSCLC.

LungTech, an EORTC Phase II trial of stereotactic body radiotherapy for centrally located lung tumours: a clinical perspective

Evidence supports stereotactic body radiotherapy (SBRT) as a curative treatment option for inoperable early stage non-small-cell lung cancer (NSCLC) resulting in high rates of tumour control and low risk of toxicity. However, promising results are mainly derived from SBRT of peripheral pulmonary lesions, whereas SBRT for the central tumours can lead to severe radiation sequelae owing to the spatial proximity to the serial organs at risk. Robust data on the tolerance of mediastinal structures to high-dose hypofractionated radiation are limited; furthermore, there are many open questions regarding the efficiency, safety and response assessment of SBRT in inoperable, centrally located early stage NSCLC, which are addressed in a prospective multicentre study [sponsored by the European Organization for Research and Treatment of Cancer (EORTC 22113-08113-LungTech)]. In this review, we summarize the current status regarding SBRT for centrally located early stage NSCLC that leads to the rationale of the LungTech trial. Outline and some essential features of the study with focus on a summary of current experiences in dose/fraction-toxicity coherences after SBRT to the mediastinal structures that lead to LungTech normal tissue constraints are provided.

Outcomes of Modestly Hypofractionated Radiation for Lung Tumors: Pre- and Mid-Treatment Positron Emission Tomography-Computed Tomography Metrics as Prognostic Factors

Many patients with lung tumors have tumors too large for stereotactic ablative radiotherapy and comorbidities precluding concurrent chemotherapy. We report the outcomes of 29 patients treated with hypofractionated radiotherapy (RT) to 60 to 66 Gy in 3-Gy fractions. We also report an exploratory analysis of the prognostic value of the pre- and mid-RT positron emission tomography-computed tomography.

INTRODUCTION

Modestly hypofractionated radiation therapy (HypoRT; 60-66 Gy in 3-Gy fractions) allows patients with locally advanced thoracic tumors and poor performance status to complete treatment within a shorter period without concurrent chemotherapy. We evaluated the outcomes and imaging prognostic factors of HypoRT.

MATERIALS AND METHODS

We retrospectively reviewed the data from all patients with primary and metastatic intrathoracic tumors treated with HypoRT from 2006 to 2012. We analyzed the survival and toxicity outcomes, including overall survival (OS), progression-free survival (PFS), local recurrence (LR), and distant metastasis. We also evaluated the following tumor metrics in an exploratory analysis: gross tumor volume (GTV), maximum standardized uptake value (SUVMax), and metabolic tumor volume using a threshold of ≥ 50% of the SUVMax (MTV50%) or the maximum gradient of fluorine-18 fluorodeoxyglucose uptake (MTVEdge). We assessed the association of these metrics and their changes from before to mid-RT using positron emission tomography-computed tomography (PET-CT) with OS and PFS.

RESULTS

We identified 29 patients, all with pre-RT and 20 with mid-RT PET-CT scans. The median follow-up period was 15 months. The 2-year overall and non-small-cell lung cancer-only rate for OS, PFS, and LR, was 59% and 59%, 52% and 41%, and 27% and 32%, respectively. No grade ≥ 3 toxicities developed. The median decrease in GTV, SUVMax, and MTVEdge was 11%, 24%, and 18%, respectively. Inferior OS was associated with a larger pre-RT MTVEdge (P = .005) and pre-RT MTV50% (P = .007). Inferior PFS was associated with a larger mid-RT SUVMax (P = .003).

CONCLUSION

These findings add to the growing body of data demonstrating promising outcomes and limited toxicity with HypoRT. The pre- and mid-RT PET-CT metrics could be useful for prognostic stratification in future clinical trials.

To SABR or not to SABR? Indications and contraindications for stereotactic ablative radiotherapy in the treatment of early-stage, oligometastatic, or oligoprogressive non-small cell lung cancer

Stereotactic ablative radiotherapy (SABR) is a highly effective treatment for early-stage non-small cell lung cancer. Although direct comparisons from randomized trials are not available, rates of both primary tumor control and distant metastasis are similar between SABR and surgery. Overall survival is lower after SABR compared with surgery, largely reflecting that a primary selection criterion for SABR has been medical inoperability because of decreased cardiopulmonary function and other comorbidities that lead to decreased survival independent of non-small cell lung cancer. Survival outcomes between SABR and surgery are much more similar in propensity-matched cohorts. Newer potential indications for SABR include treatment of operable patients; of oligometastatic lung cancer, in which SABR has emerged as an alternative to metastasectomy; and of oligoprogressive lung cancer, an attractive concept especially as improved personalized systemic therapies emerge, and prospective trials are currently being conducted in these settings. Although toxicity in modern series is low, SABR is clearly capable of producing fatal complications, and understanding the risk factors and approaches for mitigating them has been emerging in recent years. Thus, appropriate patient selection is a vital, evolving, and controversial topic.

DART-bid: dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily: high local control in early stage (I/II) non-small-cell lung cancer

BACKGROUND

While surgery is considered standard of care for early stage (I/II), non-small-cell lung cancer (NSCLC), radiotherapy is a widely accepted alternative for medically unfit patients or those who refuse surgery. International guidelines recommend several treatment options, comprising stereotactic body radiation therapy (SBRT) for small tumors, conventional radiotherapy ≥ 60 Gy for larger sized especially centrally located lesions or continuous hyperfractionated accelerated RT (CHART). This study presents clinical outcome and toxicity for patients treated with a dose-differentiated accelerated schedule using 1.8 Gy bid (DART-bid).

PATIENTS AND METHODS

Between April 2002 and December 2010, 54 patients (median age 71 years, median Karnofsky performance score 70%) were treated for early stage NSCLC. Total doses were applied according to tumor diameter: 73.8 Gy for <  2.5 cm, 79.2 Gy for 2.5-4.5 cm, 84.6 Gy for 4.5-6 cm, 90 Gy for > 6 cm.

RESULTS

The median follow-up was 28.5 months (range 2-108 months); actuarial local control (LC) at 2 and 3 years was 88%, while regional control was 100%. There were 10 patients (19%) who died of the tumor, and 18 patients (33%) died due to cardiovascular or pulmonary causes. A total of 11 patients (20%) died intercurrently without evidence of progression or treatment-related toxicity at the last follow-up, while 15 patients (28%) are alive. Acute esophagitis ≤ grade 2 occurred in 7 cases, 2 patients developed grade 2 chronic pulmonary fibrosis.

CONCLUSION

DART-bid yields high LC without significant toxicity. For centrally located and/or large (> 5 cm) early stage tumors, where SBRT is not feasible, this method might serve as radiotherapeutic alternative to present treatment recommendations, with the need of confirmation in larger cohorts.

Stereotactic ablative radiotherapy (SABR) using 70 Gy in 10 fractions for non-small cell lung cancer: exploration of clinical indications

BACKGROUND AND PURPOSE

We report our outcomes for patients with NSCLC treated with SABR to 70 Gy in 10 fractions and propose indications for this regimen as well as new dose-volume constraints.

MATERIALS AND METHODS

Volumetric image-guided SABR was used to treat 82 patients with clinical challenging NSCLC, not suitable for 50 Gy in 4 fractions, to a final dose of 70 Gy in 10 fractions. Endpoints included overall survival (OS), toxicity, and disease control.

RESULTS

At a median follow-up time of 21.1 months, 2-year OS and local control rates were 66.9% and 96.2%, respectively. The most common side effects were radiation pneumonitis (14.6% grade 2, 2.4% grade 3), followed by chest wall pain (4.9% grade 2, 1.2% grade 3). Multivariate analysis revealed chest wall V50>60 cm(3) to be associated with chest wall pain. No patient developed brachial plexopathy. One patient with bronchial tree tumor invasion died of hemoptysis.

CONCLUSIONS

SABR with 70 Gy in 10 fractions appears to achieve excellent local control and acceptable toxicity for clinically challenging cases with improved tolerance of the chest wall and brachial plexus as compared with 50 Gy in 4 fractions. This regimen may not be suitable in patients with tumor invading critical central structures. More studies are needed to validate our conclusions.

Phase II study of accelerated hypofractionated three-dimensional conformal radiotherapy for stage T1-3 N0 M0 non-small cell lung cancer: NCIC CTG BR.25

BACKGROUND

A multi-institutional phase II trial was performed to assess a hypofractionated accelerated radiotherapy regimen for early stage non-small cell lung cancer (NSCLC) in an era when stereotactic body radiotherapy was not widely available.

METHODS

Eighty patients with biopsy-proven, peripherally located, T1-3 N0 M0 NSCLC were enrolled. Eligible patients received 60 Gy in 15 fractions using a three-dimensional conformal technique without inhomogeneity correction. The gross tumour volume (GTV) was the primary tumor only, and the planning target volume (PTV) margin was 1.0 to 1.5cm. The primary endpoint was the 2-year primary tumor control rate. Toxicities were measured using the Common Terminology Criteria for Adverse Events version 3.0.

RESULTS

The median follow-up of patients was 49 months (range = 21-63 months). The median age of patients was 75.9 years. The actuarial rate of primary tumor control was 87.4% (95% confidence interval [CI] = 76.2% to 93.5%) at 2 years. Overall survival was 68.7% (95% CI = 57.2% to 77.6%) at 2 years. The actuarial rates of developing regional and distant relapse at 2 years were 8.8% (95% CI = 4.1% to 18.7%) and 21.6% (95% CI = 13.5% to 33.5%), respectively. Tumor size greater than 3cm was associated with an increased risk of developing distant relapse (hazard ratio = 3.11; 95% CI = 1.30 to 7.42; two-sided log-rank test P = .007). The most common grade 3+ toxicities were fatigue (6.3%), cough (7.5%), dyspnea (13.8%), and pneumonitis (10.0%)

CONCLUSIONS

Conformal radiotherapy to a dose of 60 Gy in 15 fractions resulted in favorable primary tumor control and overall survival rates in patients with T1-3 N0 M0 NSCLC. Severe toxicities were uncommon with this relatively simple treatment technique.

Comparison of accelerated hypofractionation and stereotactic body radiotherapy for Stage 1 and node negative Stage 2 non-small cell lung cancer (NSCLC)

PURPOSE

Stereotactic body radiation therapy (SBRT) and accelerated hypofractionated radiation therapy (AHRT) have favorable local control (LC) relative to conventional fractionation in the treatment of stage I non-small cell lung cancer (NSCLC). We report the results of our single institution experience with the treatment of early stage NSCLC with SBRT or AHRT in cases where SBRT was felt to be suboptimal.

METHODS

One hundred and sixty patients with Stage 1 and node negative Stage 2 NSCLC were treated with SBRT or AHRT from 2003 to 2011. Median follow-up was 29.4 and 19 months (mo), respectively. The median dose was 54Gy in 3 fractions (fx) (SBRT) and 70.2Gy in 26 fx (AHRT). Acute and late toxicities (tox) were graded (G) per CTCAE v4. Time to local (LF), regional (RF) and distant (DF) failure were estimated using the Kaplan-Meier method. The impact of patient and tumor related factors on LF were estimated by multivariate Cox proportional hazard model.

RESULTS

Three-year LC rates were 87.7% (SBRT) and 71.7% (AHRT). The 3-year freedom from DF was 73.3% and 68.1%. Median OS was 38.4 (95% CI 29.7-51.6) and 35 (95% CI 22-48.3) mo. No G3 or 4 tox were observed. At 1 year, 30% and 50% of complications resolved, while (5-6%) had persistent chest wall pain. Multivariate analysis demonstrated that increasing dose per fraction and tumor size (>5.5 vs. 4cm) in the AHRT and SBRT group were found to be associated with a reduced (HR 0.33 95% CI 0.13-0.84, p=0.021) and increased (HR: 6.372 95% CI 1.23-32.92, p=0.027) hazard for local failure respectively.

CONCLUSIONS

Our results compare favorably with other reports of treatment for early stage NSCLC. AHRT patients had comparable LC despite increased size and central disease. Toxicity was limited and overall survival, regional and distant recurrences were similar between groups.

Lung cancer ablation: technologies and techniques

The incidence of lung cancers in 2012 is estimated to reach 226,160 new cases, with only a third of patients suitable surgical candidates. Tumor ablation has emerged as an important and efficacious treatment option for nonsurgical lung cancer patients. This localized minimally invasive therapy is best suited for small oligonodular lesions or favorably located metastatic tumors. Radiofrequency ablation has been in use for over a decade, and newer modalities including microwave ablation, cryoablation, and irreversible electroporation have emerged as additional treatment options for patients. Ablation therapies can offer patients and clinicians a repeatable and effective therapy for palliation and, in some cases, cure of thoracic malignancies. This article discusses the available technologies and techniques available for tumor ablation of thoracic malignancies including patient selection, basic aspects of procedure technique, imaging follow-up, treatment outcomes, and comparisons between various therapies.

Strategies of dose escalation in the treatment of locally advanced non-small cell lung cancer: image guidance and beyond

Radiation dose in the setting of chemo-radiation for locally advanced non-small cell lung cancer (NSCLC) has been historically limited by the risk of normal tissue toxicity and this has been hypothesized to correlate with the poor results in regard to local tumor recurrences. Dose escalation, as a means to improve local control, with concurrent chemotherapy has been shown to be feasible with three-dimensional conformal radiotherapy in early phase studies with good clinical outcome. However, the potential superiority of moderate dose escalation to 74 Gy has not been shown in phase III randomized studies. In this review, the limitations in target volume definition in previous studies; and the factors that may be critical to safe dose escalation in the treatment of locally advanced NSCLC, such as respiratory motion management, image guidance, intensity modulation, FDG-positron emission tomography incorporation in the treatment planning process, and adaptive radiotherapy, are discussed. These factors, along with novel treatment approaches that have emerged in recent years, are proposed to warrant further investigation in future trials in a more comprehensive and integrated fashion.

New techniques for assessing response after hypofractionated radiotherapy for lung cancer

Hypofractionated radiotherapy (HFRT) is an effective and increasingly-used treatment for early stage non-small cell lung cancer (NSCLC). Stereotactic ablative radiotherapy (SABR) is a form of HFRT and delivers biologically effective doses (BEDs) in excess of 100 Gy10 in 3-8 fractions. Excellent long-term outcomes have been reported; however, response assessment following SABR is complicated as radiation induced lung injury can appear similar to a recurring tumor on CT. Current approaches to scoring treatment responses include Response Evaluation Criteria in Solid Tumors (RECIST) and positron emission tomography (PET), both of which appear to have a limited role in detecting recurrences following SABR. Novel approaches to assess response are required, but new techniques should be easily standardized across centers, cost effective, with sensitivity and specificity that improves on current CT and PET approaches. This review examines potential novel approaches, focusing on the emerging field of quantitative image feature analysis, to distinguish recurrence from fibrosis after SABR.

Hypofractionated three-dimensional conformal radiation therapy alone for centrally located cT1-3N0 non-small-cell lung cancer

PURPOSE

We retrospectively analyzed the treatment outcomes and toxicities by hypofractionated three-dimensional conformal radiation therapy (RT) alone in the patients with centrally located cT1-3N0 non-small-cell lung cancer (NSCLC).

METHODS

Sixty patients with centrally located cT1-3N0 NSCLC received definitive RT alone at 3.0 Gy per fraction for either medical comorbidity or refusal of surgery, between January 2001 and December 2010. The central tumor was defined as being within 2 cm around the proximal bronchial tree. The median total dose was 60 (39-60) Gy.

RESULTS

The local control (LC), overall survival (OS), and cause-specific survival rates at 2 and 5 years were 57.9%, 59.6%, 61.7%, and 50.1%, 33.5%, and 40.5%, respectively. Multivariate analyses showed that high cT stage (p = 0.007) and histology with NSCLC-not otherwise specified (p = 0.008) were the significantly unfavorable prognostic factors for OS, and that high cT stage (p = 0.031) and poor performance state (p = 0.007) were for LC. The LC rate at 2 years was 100% for cT1 tumor, 56.5% for cT2 tumor, and 28.6% for cT3 tumor, respectively. No patients experienced grade 3 or higher esophagitis, and three experienced grade 3 or higher pneumonitis.

CONCLUSION

Hypofractionated RT regimen for centrally located cT1-3N0 NSCLC proved safe with minimal toxicity, and, based on the excellent clinical outcomes in cT1 tumors, might serve as an alternative option for the patients who might not tolerate stereotactic body radiation therapy. As the clinical outcomes in cT2-3 tumors were still unsatisfactory, further dose intensifying regimen coupled with the use of concurrent systemic chemotherapy might be warranted.

Dose-limiting toxicity after hypofractionated dose-escalated radiotherapy in non-small-cell lung cancer

PURPOSE

Local failure rates after radiation therapy (RT) for locally advanced non-small-cell lung cancer (NSCLC) remain high. Consequently, RT dose intensification strategies continue to be explored, including hypofractionation, which allows for RT acceleration that could potentially improve outcomes. The maximum-tolerated dose (MTD) with dose-escalated hypofractionation has not been adequately defined.

PATIENTS AND METHODS

Seventy-nine patients with NSCLC were enrolled on a prospective single-institution phase I trial of dose-escalated hypofractionated RT without concurrent chemotherapy. Escalation of dose per fraction was performed according to patients' stratified risk for radiation pneumonitis with total RT doses ranging from 57 to 85.5 Gy in 25 daily fractions over 5 weeks using intensity-modulated radiotherapy. The MTD was defined as the maximum dose with ≤ 20% risk of severe toxicity.

RESULTS

No grade 3 pneumonitis was observed and an MTD for acute toxicity was not identified during patient accrual. However, with a longer follow-up period, grade 4 to 5 toxicity occurred in six patients and was correlated with total dose (P = .004). An MTD was identified at 63.25 Gy in 25 fractions. Late grade 4 to 5 toxicities were attributable to damage to central and perihilar structures and correlated with dose to the proximal bronchial tree.

CONCLUSION

Although this dose-escalation model limited the rates of clinically significant pneumonitis, dose-limiting toxicity occurred and was dominated by late radiation toxicity involving central and perihilar structures. The identified dose-response for damage to the proximal bronchial tree warrants caution in future dose-intensification protocols, especially when using hypofractionation.

Radiotherapy for a second primary lung cancer arising post-pneumonectomy: planning considerations and clinical outcomes

BACKGROUND

Second primary non-small cell lung cancer (SPLC) is a significant cause of death amongst lung cancer survivors. As subsequent surgery is seldom feasible post-pneumonectomy, we studied the long-term clinical outcomes achieved with curative radiotherapy using modern delivery techniques.

METHODS

Retrospective review of an institutional database between 2003-2011 identified 27 patients who had received curative radiotherapy for SPLC arising post-pneumonectomy. Treatments included; stereotactic ablative radiotherapy (SABR, n=20, dose 54-60 Gy in 3-8 fractions), hypofractionated radiotherapy (HFR, n=6, dose 39-60 Gy in 12-23 fractions) and conventional radiotherapy (RT, n=1, 60 Gy in 30 fractions). Clinical follow-up with a CT scan at 3, 6 and 12 months, then yearly was performed. Toxicities were scored using the common toxicity criteria for adverse events (version 4.0).

RESULTS

The median overall survival was 39 months (95% CI, 33-44 months). After a median follow-up of 52 months (95% CI, 37-67 months), any recurrence was observed in four (15%) patients. Actuarial 3-year rates of local, regional and distant recurrences were 8% (95% CI, 0-21 months), 10% (95% CI, 0-23%) and 9% (95% CI, 0-20%), respectively. Patients receiving HFR or RT all had centrally located tumors. Of the patients treated with HFR delivered 12 fractions, 75% (3/4) developed grade 3 or higher radiation pneumonitis (RP), including one probable grade 5 toxicity. Of those receiving RT or HFR in 13 or more fractions no (0/3) grade 3 or worse RP was observed, despite such treatment being used for larger tumors and resulting in worse lung dose-volume histogram metrics. All the patients who developed RP had radiotherapy plans, which prioritized the sparing of central structures over lung sparing. No non-RP grade 3 or higher toxicities were observed.

CONCLUSIONS

Curative radiotherapy is an effective treatment for SPLC arising post-pneumonectomy. For larger central tumors, our data suggests that plans should prioritize reducing lung doses above the sparing of central structures.

Cost and effectiveness of radiofrequency ablation versus limited surgical resection for stage I non-small-cell lung cancer in elderly patients: is less more?

PURPOSE

To retrospectively evaluate cost and mortality in 84 patients older than 65 years of age with stage IA or IB non-small-cell lung cancer treated with radiofrequency (RF) ablation or limited surgical resection (ie, wedge resection or segmentectomy) from the perspective of the payer, Medicare.

MATERIALS AND METHODS

From August 2000 to November 2009, 56 patients were treated with RF ablation and 28 with surgery who met the inclusion criteria. Patient health histories and billing charges from initial treatment to the study endpoint were collected. Charges were converted to 2009 Medicare reimbursement fees and cumulated by month. Time-event data were analyzed by using the Kaplan-Meier method. Survival functions and median survival estimates were reported with standard errors. Patient cohorts' survival functions were compared based on the Wilcoxon weighted χ(2) statistic.

RESULTS

Group demographics were comparable with the exception of age, with patients treated with RF ablation an average of 4 years older (95% confidence interval, 0.85-6.76). The overall mortality rate was lower in patients treated with surgery than in those treated with RF ablation (χ(2) = 8.0225, P = .0046), with a median cost per month lived for RF ablation recipients of $620.74, versus $1,195.92 for those treated with surgery (P = .0002, Wilcoxon rank-sum test).

CONCLUSIONS

Patients treated with surgery showed a significant increase in survival; however, those treated with RF ablation were significantly older. For patients who are not surgical candidates, RF ablation provides an alternative treatment option at a significantly lower cost.

New radiotherapy and chemoradiotherapy approaches for non-small-cell lung cancer

Recent advances in systemic cytotoxic and molecularly targeted therapies coupled with technologic strides in radiotherapy have the potential to improve outcomes for patients with non-small-cell lung cancer (NSCLC). Investigations are ongoing to identify optimal cytotoxin-based chemoradiotherapy platforms. The influence of specific histologic and molecular mutation status on the combination of targeted therapies and radiotherapy is also being actively studied. Although there are no convincing randomized phase III data to date supporting a survival advantage for combining molecularly targeted agents with radiation or chemoradiotherapy in the setting of locally advanced NSCLC, phase II and III studies targeted to elderly patients and those with poor performance status are elucidating preferred chemoradiotherapy strategies. Radiotherapy dose escalation did not improve chemoradiotherapy outcomes, although increasing radiation dose-intensity with modern techniques is being actively studied. As modern radiotherapy techniques have been shown to improve outcomes of some patients with limited metastatic disease, investigations are ongoing regarding how to optimally integrate them with standard chemotherapy platforms.

Is high-dose stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer (NSCLC) overkill? A systematic review

BACKGROUND AND PURPOSE

For stereotactic body radiotherapy (SBRT), typically a scheme of 60 Gy in 3-8 fractions is applied, producing local tumour control rates around 90%. The dose specification is in one point only and ignores possible underdosages at the edge of the planning target volume (PTV). We investigated the doses at the edge of the PTV and correlated this with local tumour control with the aim to shed light on the radiation dose needed to eradicate stage I NSCLC.

MATERIALS AND METHODS

Published data on the freedom from local progression (FFLP) data from SBRT and accelerated high-dose conventional radiotherapy series for stage I NSCLC with a follow up of at least 30 months were included. The EQD(2,T) was calculated from the dose at the periphery of the PTV.

RESULTS

Fifteen studies for SBRT (1076 patients) showed a median FFLP of 88.0±10.4% with a median EQD(2,T) of 76.9±17.4 Gy. The median FFLP was 87.6±6.0% for the accelerated schedules with an EQD(2,T) of 86.9±39.1 Gy, respectively. No significant relation was found between FFLP and the EQD(2,T) (p=0.23).

CONCLUSIONS

Several fractionated and accelerated schedules with equal biological doses achieve the same tumour control rates as SBRT. Lower, but more uniform doses to the whole PTV may be sufficient to achieve similar control rates, with the possibility to deliver SBRT in adapted schedules, beneficial to centrally located tumours in the vicinity of critical structures like the oesophagus and great vessels.

Outcomes of accelerated hypofractionated radiotherapy in stage i non-small-cell lung cancer

PURPOSE

Outcomes after treatment with accelerated hypofractionated radiotherapy in stage i medically inoperable non-small-cell lung cancer (nsclc) patients were determined.

METHODS

Our single-institution retrospective review looked at medically inoperable patients with T1-2N0M0 nsclc treated with accelerated hypofractionated curative-intent radiotherapy between 1999 and 2009. Patients were staged mainly by computed tomography imaging of chest and abdomen, bone scan, and computed tomography/magnetic resonance imaging of brain. Positron-emission tomography (pet) staging was performed in 6 patients. Medical charts were reviewed to determine demographics, radiotherapy details, sites of failure, toxicity (as defined by the Common Terminology Criteria for Adverse Events, version 3.0) and vital status. The cumulative incidence of local and distant failure was calculated. Overall (os) and cause-specific (css) survival were estimated by the Kaplan-Meier method.

RESULT

In the 60 patients treated during the study period, the dose regimens were 50 Gy in 20 fractions (n = 6), 55 Gy in 20 fractions (n = 8), 60 Gy in 20 fractions (n = 42), and 60 Gy in 25 fractions (n = 4). All patients were treated once daily. The median follow-up was 27 months (range: 4-94 months). The os rates at 2 and 5 years were 61% [95% confidence interval (ci): 50% to 75%] and 19% (95% ci: 10% to 34%) respectively. The css rates at 2 and 5 years were 79% (95% ci: 68% to 91%) and 39% (95% ci: 24% to 63%) respectively. The cumulative incidence of local failure was 20% at 5 years. The cumulative incidence of distant failure was 28% at 5 years. No patients experienced grade 3 or greater pneumonitis or esophagitis.

CONCLUSIONS

Accelerated hypofractionated regimens are well tolerated and provide good local control in medically inoperable patients with stage i nsclc. Such regimens may be a reasonable treatment alternative when stereotactic body radiation therapy is not feasible.

Optimal management of patients with stage I non-small-cell lung cancer and compromised cardiopulmonary function

SUMMARY Lobectomy with systematic lymph node evaluation is the standard of care for medically fit patients with stage I non-small-cell lung cancer. The definition of ‘medically inoperable’ has evolved over time as technological advances have reduced the morbidity and mortality associated with surgery. Operability is currently more appropriately described as a gradient of risk, rather than a strict characterization of inoperable versus operable. For patients who cannot tolerate a lobectomy, multiple treatment options exist: sublobar resection, fractionated radiation, stereotactic body radiation therapy (SBRT) and radiofrequency ablation. Ongoing randomized studies will provide direct comparisons of surgery versus SBRT for both standard- and high-risk operable patients. For medically inoperable patients, radiation is the standard of care, and SBRT offers high rates of local control with limited morbidity. Prospective trials will continue to inform, but in the meantime, the best approach is a multidisciplinary one in which treatment is optimized for individual patients.

Current options and controversies in the treatment of high-risk patients with early-stage non-small-cell lung cancer: a surgeon’s perspective

SUMMARY While lobectomy remains the standard of care for stage I non-small-cell lung cancer in low-to-moderate-risk patients, treatment options for the medically inoperable or high-risk population have been more challenging. Understanding what defines this high-risk/inoperable population and what treatment options are currently available are outlined in this perspective. The spectrum of surgical therapy from lobectomy to sublobar resection with or without brachytherapy will also be evaluated. Furthermore, the evolution of stereotactic body radiation therapy (SBRT) in the treatment of stage I non-small-cell lung cancer and other nonsurgical treatment options currently available will be evaluated. This will provide an understanding of comparative studies of these modalities, as well as important clinical trials on the horizon.