Stereotactic Body Radiation Therapy as Salvage for Intrathoracic Recurrence in Patients With Previously Irradiated Locally Advanced Non–Small Cell Lung Cancer

Salvage Reirradiation with Proton Beam Therapy for Locoregionally Recurrent Non-Small Cell Lung Cancer

BACKGROUND/OBJECTIVES

This retrospective study evaluates outcomes of 66 patients who underwent reirradiation (re-RT) with proton beam therapy (PBT) for recurrent non-small cell lung cancer.

METHODS

Toxicity was scored via the CTCAE v5.0, and outcomes estimated using the Kaplan-Meier method, with associations evaluated via Cox proportional hazards and logistic regression analyses.

RESULTS

Patients were treated to a median re-RT prescription of 66 Gy/33 fxs (BED10 = 79 Gy; IQR: 71-84 Gy) at an interval of 1.4 years from prior RT. Half (50%) received concurrent chemotherapy. At 14 months follow-up, the median OS and PFS were 5 months (95%CI: 13-17) and 12.5 months (95%CI: 10-15), respectively. On multivariable analysis, a higher RT dose (BED10 > 70 Gy) [HR0.37; 95%CI: 0.20-0.68, p = 0.001] and concurrent chemotherapy (HR0.48; 95%CI: 0.28-0.81, p = 0.007) were associated with improved PFS, while treatment site overlap was adversely associated (HR1.78; 95%CI: 1.05-3.02, p = 0.031). The median PFS for definitive RT with concurrent chemotherapy (n = 28), definitive RT alone (BED10 > 70 Gy) [n = 22], and lower prescription RT (BED10 < 70 Gy) [n = 16] was 15.5 months (95%CI: 7.3-23.7), 14.1 months (95%CI: 10.9-17.3), and 3.3 months (95%CI: 0-12.3), respectively (log-rank, p = 0.006), with corresponding 2-year estimates of 37% (±9), 18% (±8), and 12.5% (±8), respectively. The incidence of Grade 3+ toxicity was 10.5% (6% pulmonary; 3% esophageal; and 1.5% skin), including one Grade 4 bronchopulmonary hemorrhage but no Grade 5 events. Cases with central site overlap had higher composite Dmax to the esophagus (median 87 Gy [IQR:77-90]), great vessels (median 120 Gy [IQR:110-138]), and proximal bronchial tree (median 120 Gy [IQR:110-138]) as compared to other cases (p ≤ 0.001 for all). However, no significant associations were identified with Grade 3+ events.

CONCLUSIONS

Thoracic re-RT with PBT is an option for recurrent NSCLC with acceptable outcomes and toxicity for select patients. When feasible, higher prescription doses (BED10 > 70 Gy) should be delivered for definitive intent, and concurrent chemotherapy may benefit individual cases.

Thoracic Reirradiation with Stereotactic Body Radiation Therapy (SBRT) for Recurrent Advanced Non-Small Cell Lung Cancer (NSCLC)

PURPOSE

Non-small cell lung cancer (NSCLC) local control remains suboptimal with rates around 75%. Stereotactic body radiation therapy (SBRT) is an option for isolated local recurrences of small-volume recurrences. This study investigates the safety and efficacy of 60 Gy in 8 fractions in large-volume local recurrences.

METHODS AND MATERIALS

We conducted a retrospective chart review of patients treated with salvage SBRT for NSCLC lung parenchymal recurrence between July 2013 and February 2020. Reirradiation prescribed dose was 60 Gy in 8 fractions using the SBRT technique. The primary endpoint was local control at most recent follow-up or death. Secondary endpoints included overall survival, disease-free interval, cancer-specific survival, and treatment related toxicities.

RESULTS

Seven patients met inclusion criteria. Median follow up time was 38 months (18.1-72.4). Median age was 67 years (63-80). Median time to reirradiation was 18.2 months (7.3-28.6). Retreatment median ITV was 57.9 cc (15.8-344.6), and PTV median was 113.6 cc (38.3-506.9). Local control was maintained in 4 of 7 patients (57.1%). Two of the 7 patients (28.6%) remained alive. Median disease-free interval was 22.5 months (11-65). Three of 7 patients (42.9%) had grade 2 toxicities. One patient (14.3%) had a grade 3 rib/chest wall toxicity with concurrent disease recurrence invading the chest wall.

CONCLUSION

This study reports that SBRT of 60 Gy in 8 fractions was delivered safely and effectively to large volume recurrent NSCLC previously treated with radiation therapy. The disease-free interval of nearly 2 years is meaningful for patients' quality of life and duration of time off systemic therapy.

An algorithm for thoracic re-irradiation using biologically effective dose: a common language on how to treat in a "no-treat zone"

Background

Re-irradiation (re-RT) is a technically challenging task for which few standardized approaches exist. This is in part due to the lack of a common platform to assess dose tolerance in relation to toxicity in the re-RT setting. To better address this knowledge gap and provide new tools for studying and developing thresholds for re-RT, we developed a novel algorithm that allows for anatomically accurate three-dimensional mapping of composite biological effective dose (BED) distributions from nominal doses (Gy).

Methods

The algorithm was designed to automatically convert nominal dose from prior treatment plans to corresponding BED value maps (voxel size 2.5 mm³ and α/β of 3 for normal tissue, BED₃). Following the conversion of each plan to a BED₃ dose distribution, deformable registration was used to create a summed composite re-irradiation BED₃ plan for each patient who received two treatments. A proof-of-principle analysis was performed on 38 re-irradiation cases of initial stereotactic ablative radiotherapy (SABR) followed by either re-SABR or chemoradiation for isolated locoregional recurrence of early-stage non-small cell lung cancer.

Results

Evaluation of the algorithm-generated maps revealed appropriate conversion of physical dose to BED at each voxel. Of 14 patients receiving repeat SABR, there was one case each of grade 3 chest wall pain (7%), pneumonitis (7%), and dyspnea (7%). Of 24 patients undergoing repeat fractionated radiotherapy, grade 3 events were limited to two cases each of pneumonitis and dyspnea (8%). Composite BED₃ dosimetry for each patient who experienced grade 2–3 events is provided and may help guide development of precise cumulative dose thresholds for organs at risk in the re-RT setting.

Conclusions

This novel algorithm successfully created a voxel-by-voxel composite treatment plan using BED values. This approach may be used to more precisely examine dosimetric predictors of toxicities and to establish more accurate normal tissue constraints for re-irradiation.

Treatment outcomes of re-irradiation using stereotactic ablative radiotherapy to lung: a propensity score matching analysis

BACKGROUND

The purpose of this study was to compare the treatment efficacy and safety of re-irradiation (re-RT) using stereotactic ablative radiotherapy (SABR) and initial SABR for primary, recurrent lung cancer or metastatic lung tumor.

METHODS

A retrospective review of the medical records of 336 patients who underwent lung SABR was performed. Re-RT was defined as the overlap of the 70% isodose line of second-course SABR with that of the initial radiotherapy, and 20 patients were classified as the re-RT group. The median dose of re-RT using SABR was 54 Gy (range 48-60 Gy), and the median fraction number was 4 (range 4-6). One-to-three case-matched analysis with propensity score matching was used, and 60 patients were included in the initial SABR group of the matched cohort.

RESULTS

The 1- and 2-year local control rates for the re-RT group were 73.9% and 63.3% and those for the initial SABR group in the matched cohort were 92.9% and 87.7%, respectively (P = 0.013). There was no difference in distant metastasis-free, progression-free, and overall survival rates. The crude grade ≥ 2 toxicity rates were 40.0% for the re-RT group and 25.0% for the initial SABR group (P = 0.318). Re-RT group had higher acute grade ≥ 2 toxicity rates (25.0% vs 5.0%, P = 0.031). One incident of grade 3 toxicity (pulmonary) was reported in the re-RT group; there was no grade 4‒5 toxicity.

CONCLUSIONS

The local control rate of the in-field re-RT SABR was lower than that of the initial SABR without compromising the survival rates. The toxicity of re-RT using SABR was acceptable.

A single institutional experience with central lung stereotactic body radiation therapy demonstrating encouraging results with increased inter-fraction time

Background

Stereotactic body radiation therapy (SBRT) is an effective treatment modality for non-small cell lung cancer (NSCLC); however, there are concerns regarding potential toxicity for centrally located tumors.

Methods

This retrospective study considered patients with SBRT for central lung NSCLC (defined as a tumor within 2 cm of any mediastinal critical structure). The institutional protocol was that patients with central tumors received SBRT less frequently than daily—generally once or twice weekly.

Results

A total of 115 patients with 148 lesions were treated with SBRT to a median 45 [5–60] Gy in 4 [1–5] fractions over a median 5.3 [0–18] days. Many patients treated with this method presented with advanced disease: 58 treatments involved nodal targets, and 42 had stage 3 disease. 52% of patients had chronic obstructive pulmonary disease (COPD), and only 49% had a biopsy, often due to concerns regarding other medical comorbidities. Rates of prior chemotherapy, thoracic surgery, and thoracic radiotherapy were 32%, 21%, and 49%, respectively. Via the Kaplan-Meier method, 2-year overall survival was 65%, and 2-year local control was 77%. Two-year local-progression free survival was 53%, and 2-year progression-survival was 48%. Treatments for stage 3 disease had an impressive 82% 2-year local control that was comparable to early stage treatments. Patients with stage 3 disease had a 2-year overall survival of 59%, which trended towards decreased overall survival compared to early stage patients. There were 13 grade 1 (9%) and 14 grade 2 (9%) toxicities. There were no reported grade ≥3 acute or late toxicities and only 3 cases of pneumonitis.

Conclusions

Our series demonstrates encouraging local control with low rates of toxicity for central lung SBRT, including many stage 3 patients. This may be the result of the relatively large inter-fraction interval. This interval may allow for greater tumor effects (such as reoxygenation) and improved tolerance from normal tissues.

Is pneumonectomy justifiable for patients with a locoregional recurrence or persistent disease after curative intent chemoradiotherapy for locally advanced non-small cell lung cancer?

OBJECTIVES

Locoregional recurrence and persistent/progressive disease after curative-intent definitive chemoradiotherapy (CRT) for non-small cell lung cancer (NSCLC) is challenging to manage, as salvage options are limited. Selected patients might be candidates for resection. This study evaluated the outcomes of patients after salvage surgery for locoregional recurrence, focusing specifically on morbidity and mortality after salvage pneumonectomy.

MATERIALS AND METHODS

This retrospective study included patients from 2 tertiary referral hospitals who underwent salvage pulmonary resection for locoregional recurrence or disease persistence/progression >12 weeks after completion of curative intent high dose (>60 Gy) CRT. Disease-free (DFS) and overall survival (OS) were estimated and the influence of patient and treatment characteristics on these endpoints was assessed.

RESULTS

A total of 30 patients treated between 2015-2017 were identified with a median age of 60 years (range 42-72 years), 67 % were male. Median follow-up was 47 months (95 % CI 46-NR). Pneumonectomy was performed in 13/30 (43 %) patients and lobectomy in 17/30 (57 %). Median DFS and OS after pneumonectomy/lobectomy were 14/6 and NR/17 months, respectively. 30 and 90-day mortality for pneumonectomy/lobectomy were 0/12 % and 0/24 % respectively. More favorable survival was seen after pathologically radical resection, i.e. R0, and when surgery was performed more than 12 months after completion of CRT.

CONCLUSION

Salvage surgery, including pneumonectomy is associated with acceptable outcomes in selected patients with recurrent or persistent/progressive NSCLC after curative-intent high dose CRT. Patients should be assessed for the probability of an R0 resection, and patients with a locoregional recurrence more than 12 months after treatment with CRT may benefit most from salvage surgery.

Survival Outcomes of Salvage Therapy for Local and Regionally Recurrent NSCLC

Introduction

The treatment of locally recurrent NSCLC after initial curative therapy is variable. We sought to perform a real-world analysis of curative and palliative therapeutic strategies used in locally recurrent NSCLC and explore the impact of baseline factors and the previous and recurrent treatment on outcomes.

Methods

A retrospective cohort study was done including all patients with stage I to III NSCLC who were referred to BC Cancer and received curative-intent therapy between 2005 and 2012. Patients were followed up to determine whether they developed locoregional recurrence. Two cohorts were created: curative-intent treatment at recurrence (surgery, radiotherapy with ≥50Gy ± chemotherapy, stereotactic radiosurgery) and palliative treatment. The primary outcome was overall survival (OS).

Results

A total of 1571 patients received curative-intent therapy during the study period. Of these, 179 (11%) developed a local and regional recurrence. A total of 51 patients (28%) were treated with curative intent at recurrence (12 surgery, 39 radiotherapy ± chemotherapy), and 128 (72%) received palliative treatment only. Patients receiving curative-intent therapy were more likely to have an Eastern Cooperative Oncology Group performance status of 0 to 1 (90% versus 58%), earlier stage at diagnosis (51% stage I) and receive more aggressive staging investigations at recurrence, pathologic confirmation (75% versus 27%) and positron emission tomography (77% versus 27%). OS was longer in the cohort receiving curative-intent therapy, with an OS of 34.3 months versus 9.8 months (p < 0.001) in palliative treatment.

Conclusions

In this real-world population, isolated locoregional recurrences occurred in 11% of patients. Curative-intent treatment at recurrence is associated with a reasonable chance of long-term survival, making aggressive therapy of locoregional recurrences an important treatment consideration.

Ultra-central Thoracic Re-irradiation Using 10-fraction Stereotactic Body Radiotherapy for Recurrent Non-small-cell Lung Cancer Tumors: Preliminary Toxicity and Efficacy Outcomes

BACKGROUND

We report our clinical outcomes of patients with recurrent non-small-cell lung cancer (NSCLC) tumors with ultra-central (UC) location treated with hypofractionated 10-fraction stereotactic body radiotherapy (hSBRT) in the context of thoracic re-irradiation.

PATIENTS AND METHODS

This study was conducted from 2009 to 2017 on 20 patients with recurrent NSCLC from previous thoracic radiation treatment who underwent hSBRT to 21 total UC located recurrent tumors. The planning target volumes (PTVs) that overlapped with previous treatment fields (within the 50% isodose line) were included in this analysis with endpoints of overall survival, tumor control, and toxicity.

RESULTS

The median follow-up time was 17.8 months. The median total dose of hSBRT and total biologically effective dose (BED₁₀) were 65 Gy and 107.25 Gy, respectively. The median time from previous treatment was 14.6 months. The 1-year overall survival, progression-free survival, and local control rates were 68%, 35%, and 83%, respectively. The median time to local progression was 13.3 months. The most common toxicity was grade 2 or above pneumonitis (35%). One patient, whose tumor was abutting the esophagus, experienced grade 3 esophagitis. Two (10%) patients died from "unlikely" treatment-related hemorrhage from local tumor progression at 10 and 24 months after hSBRT. Bronchoscopic evaluation of 1 patient suggested endobronchial tumor progression, and clear radiographic evidence of treated hilar tumor progression was documented in the second patient's case.

CONCLUSION

Despite having a high-risk population with recurrent ultra-central NSCLC tumors in the setting of re-irradiation, our results demonstrate that ablative doses of hSBRT may serve as a feasible option for these challenging cases and concur with current reported literature.

What is the role of reirradiation in the management of locoregionally relapsed non small-cell lung cancer?

The prognosis of lung cancer patients has improved in the last few years. Despite definitive therapy, local recurrence or a second primary tumour can occur in many patients within previously irradiated areas. Recent developement of more accurate techniques in radiation oncology allows delivery of high radiation dose to the tumor with the aim of improving local control, delaying disease progression and in some cases even curing. Nevertheless, the use of high dose in the reirradiation setting is not without risks, especially when treatment volumes overlap with previously irradiated tissues. The risk of adverse effects must be balanced with the choice of an effective treatment by selecting suitable candidates and the best radiation technique. In this systemic review efficacy and toxicity of reirradiation in locoregionally recurrent non-small-cell lung cancer is extensively discussed. Results indicate that reirradiation might be beneficial in well-selected patients. Prospective and high quality studies are necessary in this field.

Effectiveness and Safety of Reirradiation With Stereotactic Ablative Radiotherapy of Lung Cancer After a First Course of Thoracic Radiation: A Meta-analysis

OBJECTIVE

The effectiveness and safety of reirradiation with stereotactic ablative radiotherapy (re-SABR) in patients with recurrence after a previous course of radiation are limited to small series. We carried out a meta-analysis to summarize existing data and identify trends in overall survival (OS), local control (LC), and toxicity after re-SABR in patients with recurrence of lung cancer.

MATERIALS AND METHODS

Eligible studies were identified on Medline, Embase, the Cochrane Library, and the proceedings of annual meetings through June 2019. We followed the PRISMA and MOOSE guidelines. A meta-regression analysis was carried out to assess whether there is a relationship between moderator variables and outcomes. A P-value<0.05 was considered significant.

RESULTS

Twenty observational studies with a total of 595 patients treated were included. The 2-year OS and LC were 0.54 (95% confidence interval [CI]: 0.48-0.61) and 0.73 (95% CI: 0.66-0.80), respectively. The rate of any toxicity grade ≥3 was 0.098 (95% CI: 0.06-13.6), with 9 grade 5 toxicity (1.5%). In the meta-regression, the re-SABR dose (P=0.028), tumor size (P=0.031), and time to recurrence (P=0.018) showed an association with survival. For LC, the re-SABR dose (P=0.034) and tumor size (P=0.040) were statistically significant. Any toxicity grade ≥3 showed a relationship with the cumulative dose (P=0.024). Cumulative dose ≤145 versus >145 Gy2 had 3% versus 15% (P=0.013) of any grade ≥3 toxicity.

CONCLUSIONS

Re-SABR produces satisfactory LC and OS rates with an acceptable rate of toxicity. The balancing between the re-SABR dose and the tumor location has the potential to reduce severe and fatal toxicity.

Pattern-of-failure and salvage treatment analysis after chemoradiotherapy for inoperable stage III non-small cell lung cancer

BACKGROUND

Loco-regional and distant failure are common in inoperable stage III non small-cell lung cancer (NSCLC) after chemoradiotherapy (CRT). However, there is limited real-world data on failure pattern, patient prognosis and salvage options.

METHODS

We analysed 99 consecutive patients with inoperable stage III NSCLC treated with CRT between 2011 and 2016. Follow up CT scans from date of the first-site failure were matched with the delivered radiation treatment plans. Intra-thoracic loco-regional relapse was defined as in-field (IFR) vs. out-of-field recurrence (OFR) [in- vs. outside 50Gy isodose line in the involved lung], respectively. Extracranial distant (DMs) and brain metastases (BMs) as first site of recurrence were also evaluated. Using the Kaplan-Meier method, impact of salvage surgery (sS), radiotherapy (sRT), chemotherapy (sCT) and immunotherapy (sIO) on patient survival was assessed.

RESULTS

Median follow-up was 60.0 months. Median PFS from the end of CRT for the entire cohort was 7.5 (95% CI: 6.0-9.0 months) months. Twenty-six (26%) and 25 (25%) patients developed IFR and OFR. Median time to diagnosis of IFR and OFR was 7.2 and 6.2 months. In the entire cohort, onset of IFR and OFR did not influence patient outcome. However, in 73 (74%) patients who survived longer than 12 months after initial diagnosis, IFR was a significant negative prognostic factor with a median survival of 19.3 vs 40.0 months (p < 0.001). No patients with IFR underwent sS and/or sRT. 18 (70%) and 5 (19%) patients with IFR underwent sCT and sIO. Three (12%) patients with OFR underwent sS and are still alive with 3-year survival rate of 100%. 5 (20%) patients with OFR underwent sRT with a median survival of 71.2 vs 19.1 months (p = 0.014). Four (16%) patients with OFR received sIO with a numerical survival benefit (64.6 vs. 26.4 months, p = 0.222). DMs and BMs were detected in 27 (27%) and 16 (16%) patients after median time of 5.8 and 5.13 months. Both had no impact on patient outcome in the entire cohort. However, patients with more than three BMs showed significantly poor OS (9.3 vs 26.0 months; p = 0.012).

CONCLUSIONS

After completion of CRT, IFR was a negative prognostic factor in those patients, who survived longer than 12 months after initial diagnosis. Patients with OFR benefit significantly from salvage local treatment. Patients with more than three BMs as first site of failure had a significantly inferior outcome.

Stereotactic Body Radiation Therapy for Salvage Treatment of Recurrent Non-Small Cell Lung Cancer

PURPOSE

This study analyzes the outcomes and toxicity of stereotactic body radiation therapy (SBRT) as salvage treatment for recurrent non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

This retrospective analysis considered patients treated with thoracic SBRT and a history of prior external beam radiation therapy (EBRT), SBRT, or surgical resection for NSCLC. Follow-up included positron emission tomography and computed tomography imaging at 2- to 3-month intervals. Key outcomes were presented with the Kaplan-Meier method.

RESULTS

Forty patients with 52 treatments were included at a mean of 11.82 months after treatment with EBRT (n = 21), SBRT (n = 15), surgical resection (n = 9), and SBRT after EBRT (n = 7). Median imaging and clinical follow-up were 13.39 and 19.01 months, respectively. SBRT delivered a median dose of 40 Gy in 4 fractions. Median biologically effective dose (BED) was 79.60 Gy. Median gross tumor volume and planning target volume were 10.80 and 26.25 cm³, respectively. Local control was 65%, with a median time to local failure of 13.52 months. Local control was 87% after previous SBRT but only 33% after surgery. Median overall survival was 24.46 months, and median progression-free survival (PFS) was 14.11 months. Patients presenting after previous SBRT had improved local control (P = .021), and the same result was obtained including patients with SBRT after EBRT (P = .0037). Treatments after surgical resection trended toward worse local control (P = .061). Patients with BED ≥80 Gy had improved local PFS (P = .032), PFS (P = .021), time without any treatment failure (P = .033), and time to local failure (P = .041). Using the Kaplan-Meier method, BED ≥80 Gy was predictive of improved local PFS (P = .01) and PFS (P < .005). Toxicity consisted of 10 instances of grade <3 toxicity (16%) and no grade ≥3 toxicity.

CONCLUSIONS

Salvage treatment for recurrent NSCLC with SBRT was effective and well tolerated, particularly after initial treatment with SBRT. When possible, salvage SBRT should aim to achieve a BED of ≥80 Gy.

Is salvage surgery for patients with lung cancer after carbon ion radiotherapy easy or difficult?

Carbon ion radiotherapy (CIRT) shows higher local control rates and minimal damage to normal lung parenchyma compared with conventional radiotherapy; however, some patients experience local recurrence. The efficacy and safety of salvage surgery after CIRT for non-small-cell lung cancer are unclear. We reviewed clinical, surgical, pathological and prognostic data of 6 patients who underwent salvage surgery after CIRT between 2010 and 2015. All patients were men with a smoking history, and their median age was 67 years. The time from CIRT to surgery was 18 (range 12-24) months. All patients underwent at least lobectomy with mediastinal node dissection. Viable tumour cells were confirmed pathologically in all cases. Five patients required combined resection or extra procedure because of strong adhesions and the possibility of tumour extension; however, none of the patients had a tumour invasion to the adjacent organ. None of the patients had severe complications, perioperative death and local recurrence, and 3 patients are alive without recurrence (range 28-84 months). Salvage surgery appears to be safe and effective. Even though the tumours did not invade the adjacent organs, combined resection was required because of severe adhesion.

Lung stereotactic body radiotherapy after past ablative therapy: a single institution case series

Aim

Non-small-cell lung cancer recurs locally 10-40% of the time after local therapy, presenting a therapeutic challenge given poor pulmonary reserve. Herein, we seek to evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for retreatment of such patients.

Methods

We identified and reviewed clinical outcomes in ten patients with recurrent non-small-cell lung cancer after past vicryl mesh brachytherapy.

Results

Ten patients with a median age of 77 were treated to a median dose of 48 Gy in five fractions. Local control at 1 year was 88%. There was one distant failure at 29 months. There was no significant toxicity after SBRT.

Conclusion

SBRT is safe and effective when used for re-irradiation after past ablative therapies.

Chest Wall Toxicity After Stereotactic Body Radiation Therapy: A Pooled Analysis of 57 Studies

PURPOSE

The significance of clinical and dosimetric risk factors in relation to chest wall (CW) injury after stereotactic body radiation therapy (SBRT) for lung tumors were analyzed through a meta-analysis of 57 published studies.

METHODS AND MATERIALS

Studies related to CW injury after lung SBRT were obtained through searching PubMed, Embase, and Cochrane electronic databases. An estimate of the incidence of CW pain (CWP) or rib fracture (RF) was derived using a Bayesian hierarchical model. Linear regression analysis was performed to assess the relationship between CWP or RF and clinical or dosimetric factors.

RESULTS

A total of 57 studies incorporating 5985 cases reporting clinical data on CW injury after SBRT were analyzed. The overall CWP and RF rates by Bayesian hierarchical modeling were 11.0% (95% confidence interval [CI], 8.0-14.4) and 6.3% (95% CI, 3.7-9.7), respectively. The rates of grade ≥2 and grade ≥3 CWP were 6.2% (95% CI, 3.88-8.93) and 1.2% (95% CI, 0.48-2.12), respectively. Sex was significantly correlated with RF (P < .001), with female patients having a greater risk of RF than male patients (hazard ratio = 0.59; 95% CI, 0.46-0.76). No correlation was found between RF, grade ≥2 CWP, or grade ≥3 CWP, with the clinical and dosimetric factors of age, tumor size, origin of lung tumor, gross tumor volume, planning target volume, fractional dose, number of fractions, or biologically effective dose. However, tumor to CW distance (<16-25 mm), body mass index, maximum dose (Dmax) of 0.5 to 5 cm³, and the volume of CW or ribs receiving >30 Gy were significantly associated with CWP and RF.

CONCLUSIONS

The overall rates of RF and grade ≥2 CWP after thoracic SBRT are relatively low. Sex, tumor to CW distance, maximum dose, and the radiation exposure of the CW or ribs are factors associated with the risk of CW toxicity after SBRT.

Reirradiation for locoregionally recurrent non-small cell lung cancer

Locoregional failure in non-small cell lung cancer (NSCLC) remains high, and the management for recurrent disease in the setting of prior radiotherapy is difficult. Retreatment options such as surgery or systemic therapy are typically limited or frequently result in suboptimal outcomes. Reirradiation (reRT) of thoracic malignancies may be an optimal strategy for providing definitive local control and offering a new chance of cure. Yet, retreatment with radiation therapy can be challenging for fear of excessive toxicities and the inability to safely deliver definitive (≥60 Gy) doses of reRT. However, with recent improvements in radiation delivery techniques and image-guidance, dose-escalation with reRT is possible and outcomes are encouraging. Here, we present a review of various radiation techniques, clinical outcomes and associated toxicities in patients with locoregionally recurrent NSCLC treated primarily with reRT.

The risk and predictors for severe radiation pneumonitis in lung cancer patients treated with thoracic reirradiation

BACKGROUND

Thoracic reirradiation (re-RT) is increasingly administered. However, radiation pneumonitis (RP) remains to be the most common side effect from retreatment. This study aimed to determine the risk and predictors for severe RP in patients receiving thoracic re-RT.

METHODS

Sixty seven patients with lung cancer received thoracic re-RT for recurrent or metastatic disease. Three-dimensional conformal radiotherapy (3D-CRT)/intensity modulated radiotherapy (IMRT) was used for 60 patients, and stereotactic body radiation therapy (SBRT) was used in 7 patients. Deformable image registration (DIR) was performed to create a composite plan. Severe (grade ≥ 3) RP was graded according to Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

Eighteen patients (26.9%) developed grade ≥ 3 RP (17 of grade 3, and 1 of grade 4). In univariate analyses, V5 and mean lung dose (MLD) of initial RT or re-RT plans, V5 and V20 of composite plans, and the overlap between V5 of initial RT and V5 of re-RT plans/V5 of re-RT plans (overlap-V5/re-V5) were significantly associated with grade ≥ 3 RP (P < 0.05 for each comparison). Multivariate analysis revealed that MLD of the initial RT plans (HR = 14.515, 95%CI:1.778-118.494, P = 0.013), V5 of the composite plans (HR = 7.398, 95%CI:1.319-41.495, P = 0.023), and overlap-V5/re-V5 (P = 0.041) were independent predictors for grade ≥ 3 RP. Out-of-field failures with medium overlap-V5/re-V5 of 0.4-0.8 was associated with higher risk of grade ≥ 3 RP compared with in-field failures (18.3% vs. 50%, P = 0.014).

CONCLUSIONS

The risk of grade ≥ 3 RP could be predicted not only by dose-volume variables from re-RT plan, but also by some from initial-RT and composite plans. Out-of-field failures was associated with higher risk of severe RP compared with in-field failures in some cases.

Stereotactic body radiotherapy as salvage treatment for recurrence of non-small cell lung cancer after prior surgery or radiotherapy

Treatment options for thoracic recurrences of non-small cell lung cancer (NSCLC) are limited. Stereotactic body radiation therapy (SBRT) is an emerging, potentially effective technology to manage recurrent NSCLC, although with limited prospective studies. This work reviews the outcomes of patients undergoing salvage SBRT for pulmonary recurrences after prior resection or prior radiotherapy for NSCLC. Following salvage SBRT, after prior external beam radiation (SBRT or conventionally fractionated), the 2-year overall survival (OS) ranged from 37% to 79% in 11 of the studies (397 patients) reviewed here, while the 2-year local control (LC) ranged from 37% to 90% in 6 studies that reported that outcome. Toxicity risks are acceptable albeit with appreciable risks of severe to potentially fatal toxicity, necessitating the need to weigh risks vs. benefits in the re-irradiation setting. There were fewer studies on the use of SBRT after prior resection. Following salvage SBRT, after prior resection, the 2-year OS ranged from 56% to 68% in 4 studies (131 patients) reviewed here, while the 2-year LC ranged from 83% to 100% in 3 of these studies. SBRT in the salvage setting after prior resection appeared to be well-tolerated, with toxicity risks comparable to historical patients treated with SBRT alone (i.e., SBRT without prior resection, which is not reviewed here). The data are limited due to the retrospective nature of published studies (all but 4 with <40 patients), with various clinical scenarios (i.e., original NSCLC stage, prior treatment, location of target amenable to salvage SBRT) and a range of SBRT dosing and techniques. More studies are needed to better understand the tumor control, survival and toxicity of SBRT for salvage therapy of NSCLC patients, as well as the potentially prognostic factors that could affect these outcomes.

Serious gastric perforation after second stereotactic body radiotherapy for peripheral lung cancer that recurred after initial stereotactic body radiotherapy: a case report

Background

In recent reports, re-irradiation with stereotactic body radiotherapy for lung tumors in patients previously treated with thoracic radiation therapy resulted in several serious toxicities. Serious non-lung toxicities were observed mostly in patients with central tumors, but we experienced a case of fatal gastric perforation after a second stereotactic body radiotherapy in a patient with a peripheral lung tumor.

Case presentation

An 83-year-old Asian man was diagnosed with T2N0M0 lung cancer in the form of squamous cell carcinoma in the lower lobe of his left lung. He was treated with stereotactic body radiotherapy of 40 Gy in 4 fractions and the tumor decreased in size in partial response. The local tumor recurred 8 months after the first stereotactic body radiotherapy, and he was re-irradiated with a second stereotactic body radiotherapy of 50 Gy in 4 fractions. A Sengstaken–Blakemore tube was inserted below his diaphragm by laparoscopic surgery before the second stereotactic body radiotherapy in order to reduce the stomach dose by keeping his stomach apart from the tumor. Two months after the second stereotactic body radiotherapy, he developed fatal gastric perforation and gastropleural fistula penetrating his diaphragm.

Conclusions

To the best of our knowledge, this is the first report about a gastric perforation after stereotactic body radiotherapy for lung tumors and it warns of serious complication of stereotactic body radiotherapy in not only centrally located but also peripherally located tumors like in this case.

Thoracic reirradiation with SBRT for residual/recurrent and new primary NSCLC within or immediately adjacent to a prior high-dose radiation field

PURPOSE

Local failure following concurrent chemoradiation and in-lobe failures following stereotactic body radiation therapy (SBRT) are common. We evaluated our institutional experience using SBRT as salvage in this setting.

METHODS AND MATERIALS

Seventy-two patients were reirradiated with SBRT for residual, locally recurrent, or new primary non-small cell lung cancer within or adjacent to a high-dose external beam radiation therapy or SBRT field. Kaplan-Meier analysis with log-rank test were used to estimate endpoints and differentiate cohorts.

RESULTS

Median follow-up was 17.9 months. Patients had residual or recurrent disease (54.2%); 45.8% had new lung primaries. Median reirradiated T size was 2.5 cm (range, 0.8-7.8 cm). Median pre-retreatment maximum standardized uptake value (SUV_max) was 7.15 (range, 1.2-37.6). The most common SBRT reirradiation regimen was 48 Gy in 4 fractions (range, 17-60 Gy in 1-5 fractions). Median progression-free survival was 15.2 months, and median overall survival was 20.8 months. Two-year local failure was 21.6%. Patients with SUV_max at reirradiation <7.0 had a 2-year local control of 93.1% versus 61.1% above the median (P < .001). The 2-year rate of distant metastases was 10.4% versus 54.1% in patients treated for a new primary versus residual or recurrent disease (P < .001). Median progression-free survival was 31.9 months versus 8.4 months, respectively (P = .037). Median survival of patients treated for new primary was 25.2 months versus 16.2 months with residual or recurrent disease (P = .049), and median survival for patients with reirradiation SUV_max below the median was 42.0 months versus 9.8 months above the median (P < .001). Acute any-grade toxicity was seen in 29.2% of patients, acute grade 3 toxicity in 11.1%, and late grade 3 toxicity in 1.4% with no treatment-related deaths.

CONCLUSIONS

SBRT appears to be a safe and effective means of salvaging recurrent, residual, or new primary NSCLC in or adjacent to a previous high-dose radiation field.

Five-fraction SBRT for ultra-central NSCLC in-field recurrences following high-dose conventional radiation

Purpose/objective

Local treatment options for patients with in-field non-small cell lung cancer (NSCLC) recurrence following conventionally fractionated external beam radiation therapy (CF-EBRT) are limited. Stereotactic body radiation therapy (SBRT) is a promising modality to achieve reasonable local control, although toxicity remains a concern.

Materials/methods

Patients previously treated with high-dose CF-EBRT (≥59.4 Gy, ≤3 Gy/fraction) for non-metastatic NSCLC who underwent salvage SBRT for localized ultra-central in-field recurrence were included in this analysis. Ultra-central recurrences were defined as those abutting the trachea, mainstem bronchus, or esophagus and included both parenchymal and nodal recurrences. The Kaplan-Meier method was used to estimate local control and overall survival. Durable local control was defined as ≥12 months. Toxicity was scored per the CTC-AE v4.0.

Results

Twenty patients were treated with five-fraction robotic SBRT for ultra-central in-field recurrence following CF-EBRT. Fifty percent of recurrences were adenocarcinoma, while 35% of tumors were classified as squamous cell carcinoma. The median interval between the end of CF-EBRT and SBRT was 23.3 months (range: 2.6 – 93.6 months). The median CF-EBRT dose was 63 Gy (range: 59.4 – 75 Gy), the median SBRT dose was 35 Gy (range: 25 – 45 Gy), and the median total equivalent dose in 2 Gy fractions (EQD2) was 116 Gy (range: 91.3 – 136.7 Gy). At a median follow-up of 12 months for all patients and 37.5 months in surviving patients, the majority of patients (90%) have died. High-dose SBRT was associated with improved local control (p < .01), and the one-year overall survival and local control were 77.8% and 66.7% respectively in this sub-group. No late esophageal toxicity was noted, although a patient who received an SBRT dose of 45 Gy (total EQD2: 129.7 Gy) experienced grade 5 hemoptysis 35 months following treatment.

Conclusions

Although the overall prognosis for patients with in-field ultra-central NSCLC recurrences following CF-EBRT remains grim, five-fraction SBRT was well tolerated with an acceptable toxicity profile. Dose escalation above 35 Gy may offer improved local control, however caution is warranted when treating high-risk recurrences with aggressive regimens.

Reirradiation of thoracic cancers with intensity modulated proton therapy

PURPOSE

Reirradiation of thoracic malignancies is a treatment challenge, with concerns for toxicity and the inability to deliver definitive doses. Intensity modulated proton therapy (IMPT) may allow safe delivery of a higher dose of radiation to the tumor while minimizing toxicities.

METHODS AND MATERIALS

Between 2011 and 2016, 27 patients who received IMPT for reirradiation of thoracic malignancies with definitive intent were retrospectively analyzed. Patients were included if they received a prior thoracic radiation course. All doses were recalculated to an equivalent dose in 2-Gy fractions (EQD2). Patients received IMPT to a median dose of 66 EQD2 Gy (range, 43.2-84 Gy) for recurrence of thoracic cancer (93%) or sequentially after a course of thoracic stereotactic ablative radiation therapy (7%).

RESULTS

Twenty-two patients (81%) were treated for non-small cell lung cancer. The median time to reirradiation was 29.5 months. At a median follow-up for all patients of 11.2 months (25.9 surviving patients), the median overall survival was 18.0 months, with a 1-year overall survival of 54%. Four patients (15%) experienced an in-field local failure (LF), with a 1-year freedom from LF rate of 78%. The 1-year freedom from locoregional failure and 1-year progression-free survival rates were 61% and 51%, respectively. Patients who received 66 EQD2 Gy or higher had improved 1-year freedom from LF (100% vs 49%; P = .013), 1-year freedom from locoregional failure (84% vs 23%; P = .035), and 1-year progression-free survival (76% vs 14%; P = .050). Reirradiation was well tolerated, with only 2 patients (7%) experiencing late grade 3 pulmonary toxicity, and none with grade 3 or higher esophagitis. There were no grade 4-5 toxicities.

CONCLUSIONS

These data represent the largest series of patients treated with IMPT for definitive reirradiation of thoracic cancers. They demonstrate that IMPT provided durable local control with minimal toxicity and suggest that higher doses may improve outcomes.

Long-Term Outcomes of Salvage Stereotactic Ablative Radiotherapy for Isolated Lung Recurrence of Non-Small Cell Lung Cancer: A Phase II Clinical Trial

OBJECTIVES

Our goal was to evaluate stereotactic ablative radiotherapy (SABR) as a salvage option for isolated recurrence of NSCLC in the lung parenchyma after definitive treatment of stage I to III disease.

METHODS

Patients who had histologically confirmed, positron emission tomography-staged, isolated NSCLC recurring locally or metastasis in the lung parenchyma (≤3 cm, suitable for SABR) after previous definitive treatment were prospectively enrolled in this trial and treated with volumetric, image-guided SABR to 50 Gy in four fractions. Patients were then followed with computed tomography or positron emission tomography/computed tomography. Primary end points included the pattern of failure after salvage SABR, overall survival (OS), and progression-free survival (PFS).

RESULTS

Fifty-nine patients with recurrent disease were treated with salvage SABR. The median age was 70 years (range 45-86 years), and the median follow-up time after salvage SABR was 58.3 months. Re-recurrence after salvage SABR developed in 19 patients (32%). Measuring from the date of salvage SABR, the estimated 5-year rates of local, regional, and distant failure were 5.2%, 10.3%, and 22.4%, respectively; the estimated PFS was 46.2% at 3 years and 41.1% at 5 years; and the OS rates were 63.5% at 3 years and 56.5% at 5 years. A high post-SABR neutrophil-to-lymphocyte ratio was found to predict poor survival. Grade 3 treatment-related adverse events developed in three patients (5%). No patient had a grade 4 or 5 event.

CONCLUSION

Our study showed that salvage SABR provides excellent 5-year OS, local control, and PFS rates with minimal toxicity for patients with isolated NSCLC recurrence in the lung parenchyma. These results are striking and comparable to historically reported outcomes of patients with primary early-stage NSCLC treated with definitive SABR. SABR appears to be a very effective and safe salvage option for patients with isolated lung parenchyma recurrent disease after definitive treatment and should be considered along with surgery as a potential first-line option for patients with local lung parenchymal recurrent disease.

Hypofractionated radiotherapy for medically inoperable stage I non-small cell lung cancer

BACKGROUND

To investigate the clinical outcomes and toxicity of hypofractionated radiotherapy for medically inoperable stage I non-small cell lung cancer (NSCLC).

METHODS

Patients treated with radiotherapy at a dose of 4-6 Gy per fraction using fixed-field intensity modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT) at our hospital from June 2005 to December 2013 were analyzed. The total prescription doses ranged from 50-78 Gy with 4-6 Gy per fraction. The median follow-up period was 24 months.

RESULTS

A total of 65 patients with stage I NSCLC were analyzed, including 43 primary NSCLC patients and 22 patients with recurrent or second primary NSCLC. An objective response (complete or partial response) was achieved at six months in 84.6% of patients. The three-year local control rate was 90.8%. Kaplan-Meier estimates of local failure-free, progression-free, overall, and cancer-specific survival rates at three years were 90.3%, 64.3%, 68.9%, and 88.8%, respectively. The rate of symptomatic radiation pneumonitis was 16.9%, and no grade 4-5 toxicity was observed.

CONCLUSION

Favorable local control and outcome was achieved with hypofractionated radiotherapy in patients with inoperable stage I NSCLC with acceptable toxicity. The most common schedule of 6 Gy × 12 fractions may be a promising regimen, and a prospective study is in process.

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.