Update of a Prospective Study of Stereotactic Body Radiation Therapy for Post-Chemoradiation Residual Disease in Stage II/III Non-Small Cell Lung Cancer

A Phase 2 Trial of Primary Tumor Stereotactic Body Radiation Therapy Boost Before Concurrent Chemoradiation for Locally Advanced Non-Small Cell Lung Cancer

PURPOSE

Primary tumor failure is common in patients treated with chemoradiation (CRT) for locally advanced NSCLC (LA-NSCLC). Stereotactic body radiation therapy (SBRT) yields high rates of primary tumor control (PTC) in early-stage NSCLC. This trial tested an SBRT boost to the primary tumor before the start of CRT to improve PTC.

METHODS AND MATERIALS

Patients with LA-NSCLC received an SBRT boost in 2 fractions (central location 12 Gy, peripheral location 16 Gy) to the primary tumor, followed by standard CRT (60 Gy in 30 fractions). The primary objective was PTC rate at 1 year, and the hypothesis was that the 1-year PTC rate would be ≥90%. Secondary objectives included objective response rate, regional and distant control, disease-free survival (DFS), and overall survival (OS). Correlative studies included functional magnetic resonance imaging and blood-based miRNA analysis.

RESULTS

The study enrolled 21 patients (10 men and 11 women); the median age was 62 years (range, 52-78). The median pretreatment primary tumor size was 5.0 cm (range, 1.0-8.3). The most common nonhematologic toxicities were pneumonitis, fatigue, esophagitis/dysphagia, dyspnea, and cough. Only 1 treatment-related grade 4 nonhematologic toxicity occurred (respiratory failure/radiation pneumonitis), and no grade 5 toxicities occurred. The objective response rate at 3 and 6 months was 72.7% and 80.0%, respectively, and PTC at 1 and 2 years was 100% and 92.3%, respectively. The 2-year regional and distant control rates were 81.6% and 70.3%, respectively. Disease-free survival and overall survival at 2 years were 46.1% and 50.3%, respectively, and median survival was 37.8 months. Functional magnetic resonance imaging detected a mean relative decrease in blood oxygenation level-dependent signal of -87.1% (P = .05), and miR.142.3p was correlated with increased risk of grade ≥3 pulmonary toxicity (P = .01).

CONCLUSIONS

Dose escalation to the primary tumor using upfront SBRT appears feasible and safe. PTC was high and other oncologic endpoints compared favorably to standard treatment. Functional magnetic resonance imaging suggested changes in oxygenation with the first SBRT boost dose, and miR.142.3p was correlated with pulmonary toxicity.

Stereotactic boost on residual disease after external-beam irradiation in clinical stage III non-small cell lung cancer: mature results of stereotactic body radiation therapy post radiation therapy (SBRTpostRT) study

PURPOSE

To evaluate the role of stereotactic body radiation therapy (SBRT) delivered after external-beam fractionated irradiation in non-small-cell lung cancer (NSCLC) patients with clinical stage III A, B.

MATERIALS AND METHODS

All patients received three-dimensional conformal radiotherapy (3D-CRT) or intensity modulated radiation therapy (IMRT) (60-66 Gy/30-33 fractions of 2 Gy/5 days a week) with or without concomitant chemotherapy. Within 60 days from the end of irradiation, a SBRT boost (12-22 Gy in 1-3 fractions) was delivered on the residual disease.

RESULTS

Here we report the mature results of 23 patients homogeneously treated and followed up for a median time of 5.35 years (range 4.16-10.16). The rate of overall clinical response after external beam and stereotactic boost was 100%. No treatment-related mortality was recorded. Radiation-related acute toxicities with a grade ≥ 2 were observed in 6/23 patients (26.1%): 4/23 (17.4%) had esophagitis with mild esophageal pain (G2); in 2/23 (8.7%) clinical radiation pneumonitis G2 was observed. Lung fibrosis (20/23 patients, 86.95%) represented a typical late tissue damage, which was symptomatic in one patient. Median disease-free survival (DFS) and overall survival (OS) were 27.8 (95% CI, 4.2-51.3) and 56.7 months (95% CI, 34.9-78.5), respectively. Median local progression-free survival (PFS) was 17 months (range 11.6-22.4), with a median distant PFS of 18 months (range 9.6-26.4). The 5-year actuarial DFS and OS rates were 28.7% and 35.2%, respectively.

CONCLUSIONS

We confirm that a stereotactic boost after radical irradiation is feasible in stage III NSCLC patients. All fit patients who have no indication to adjuvant immunotherapy and presenting residual disease after curative irradiation could benefit from stereotactic boost because outcomes seem to be better than might be historically assumed.

Stereotactic body radiation therapy in unresectable stage III non-small cell lung cancer: A systematic review

In unresectable stage III non-small cell lung cancer (NSCLC), the standard of care for most fit patients is concurrent chemotherapy with normofractionated radiotherapy (NFRT), followed by durvalumab consolidation. Nevertheless, almost half of patients will present locoregional or metastatic intrathoracic relapse. Improving locoregional control thus remains an important objective. For this purpose, stereotactic body radiotherapy (SBRT) may be a relevant treatment modality. We performed a systematic review of the literature that evaluate the efficacy and safety of SBRT in this situation, either instead of or in addition to NFRT. Among 1788 unique reports, 18 met the inclusion criteria. They included 447 patients and were mainly prospective (n = 10, including 5 phase 2 trials). In none, maintenance durvalumab was administered. Most reported SBRT boost after NFRT (n = 8), or definitive tumor and nodal SBRT (n = 7). Median OS varied from 10 to 52 months, due to the heterogeneity of the included populations and according to treatment regimen. The rate of severe side effects was low, with <5 % grade 5 toxicity, and mainly observed when mediastinal SBRT was performed without dose constraints to the proximal bronchovascular tree. It was suggested that a biologically effective dose higher than 112.3 Gy may increase locoregional control. SBRT for selected stage III NSCLC bears potential to improve loco-regional tumor control, but at present, this should only be done in prospective clinical trials.

Systematic review of stereotactic body radiotherapy in stage III non-small cell lung cancer

Despite adequate treatment, 50% of stage III locally advanced inoperable non-small cell lung cancer (NSCLC) patients have a locoregional relapse. Local control on early stages on the contrary, is as high as 85-90% with stereotactic body radiotherapy (SBRT). The addition of SBRT to conventional chemoradiation or its use in monotherapy in stage III NSCLC is a novel strategy to decrease local failure that has been explored by various authors. This is a systematic review of studies using SBRT in inoperable stage III NSCLC. Search results obtained 141 articles of which only 6 original studies were pointed as relevant. Three of these studies were prospective, of which 2 were phase I dose-scalation studies and remaining 3 were retrospective. In summary, SBRT outcomes on 134 patients were included. Median dose in the SBRT treatment was 22.5 Gy in 2 to 7 fractions. Obtained global toxicity was 3.7% grade 5 and 14.17% grade 3. Dose-escalation studies proposed a 2 fraction SBRT schedule of 20-24 Gy, obtaining a 78% local control rate at 1 year and an OS of 67%. Initial improvement in local control with this innovative therapeutic strategy has led to ongoing phase II and III clinical trials that will evaluate the efficiency of SBRT in stage III NSCLC clinical scenario.

Trimodality therapy for superior sulcus tumour: experience of a single institution over 19 years

OBJECTIVES

Induction chemoradiotherapy followed by surgery is the standard treatment for superior sulcus tumours (SSTs). However, the protocols, chemotherapy agents and cycles used as well as the mode and intensity of radiotherapy vary between institutions. Thus, the objective of the study was to investigate the effects of trimodality therapy on the outcomes of patients with SSTs.

METHODS

Sixty patients with SSTs were enrolled between January 1999 and December 2017. Induction therapy consisted primarily of 2 cycles of mitomycin-vindesine-cisplatin or cisplatin-vinorelbine delivered concurrently to the tumour with 40-45 Gy of radiation. Surgery was performed 2-6 weeks after completion of induction therapy.

RESULTS

Fifty-four (90%) patients underwent radical surgical resection. Complete pathological resection was achieved in 44 patients (81%). There was no 30-day mortality. After a median follow-up of 57.0 months, 19 (35%) patients experienced recurrence, and 8 (15%) patients showed brain metastasis. A pathological complete response (PCR) was observed in 12 (22%) patients. The 5-year survival rate for the entire population (n = 54) was 69% (95% confidence interval 55-81%). The survival rate was better for patients who underwent complete resection than for those who underwent incomplete resection (73% vs 51%, P = 0.46). A better survival rate was evident in patients with PCR than in those without PCR (92% vs 62%, P = 0.12).

CONCLUSIONS

Trimodality therapy for SSTs was efficacious and associated with favourable outcomes, with acceptable morbidity and mortality. PCR in patients with resected SSTs reveals promising long-term survival prospects with the trimodality therapy.

The Role of Positron Emission Tomography Imaging in Radiotherapy Target Delineation

Positron emission tomography (PET) is an advanced functional imaging modality in oncology care for the diagnosis, staging, prognostication, and surveillance of numerous malignancies. PET can also offer considerable advantages for target volume delineation as part of radiation treatment planning. In this review, data and clinical practice from 6 general oncology disease sites are assessed to descriptively evaluate the role of PET in target volume delineation. Also highlighted are several specific and practical utilities for PET imaging in radiation treatment planning. Publication of several ongoing prospective trials in the future may further expand the utility of PET for target delineation and patient care.

The evolving toxicity profile of SBRT for lung cancer

Stereotactic body radiation therapy (SBRT) is an effective and well tolerated treatment for early stage non-small cell lung cancer (NSCLC). The high doses used in thoracic SBRT can sometimes cause adverse effects ranging from mild fatigue and transient esophagitis to fatal events such as pneumonitis or hemorrhage. Efforts continue to expand in both the utility of this technique as well as our understanding of the mechanisms of the adverse effects it can cause. In this review, we discuss the current literature regarding the potential mechanisms, dosimetric constraints and toxicities associated with SBRT alone and in conjunction with definitive chemoradiotherapy and immunotherapy. As the use of SBRT expands to these spheres, we examine the available recommendations for mitigating potential associated treatment related toxicities.

Implications of Pathologic Complete Response Beyond Mediastinal Nodal Clearance With High-Dose Neoadjuvant Chemoradiation Therapy in Locally Advanced, Non-Small Cell Lung Cancer

PURPOSE

To determine, in a retrospective analysis of a large cohort of stage III non-small cell lung cancer patients treated with curative intent at our institution, whether having a pathologic complete response (pCR) influenced overall survival (OS) or freedom from recurrence (FFR) in patients who underwent definitive (≥60 Gy) neoadjuvant doses of chemoradiation (CRT).

METHODS AND MATERIALS

At our institution, 355 patients with locally advanced non-small cell lung cancer were treated with curative intent with definitive CRT (January 2000-December 2013), of whom 111 underwent mediastinal reassessment for possible surgical resection. Ultimately 88 patients received trimodality therapy. Chi-squared analysis was used to compare categorical variables. The Kaplan-Meier analysis was performed to estimate OS and FFR, with Cox regression used to determine the absolute hazards.

RESULTS

Using high-dose neoadjuvant CRT, we observed a mediastinal nodal clearance (MNC) rate of 74% (82 of 111 patients) and pCR rate of 48% (37 of 77 patients). With a median follow-up of 34.2 months (range, 3-177 months), MNC resulted in improved OS and FFR on both univariate (OS: hazard ratio [HR] 0.455, 95% confidence interval [CI] 0.272-0.763, P = .004; FFR: HR 0.426, 95% CI 0.250-0.726, P = .002) and multivariate analysis (OS: HR 0.460, 95% CI 0.239-0.699, P = .001; FFR: HR 0.455, 95% CI 0.266-0.778, P = .004). However, pCR did not independently impact OS (P = .918) or FFR (P = .474).

CONCLUSIONS

Mediastinal nodal clearance after CRT continues to be predictive of improved survival for patients undergoing trimodality therapy. However, a pCR at both the primary and mediastinum did not further improve survival outcomes. Future therapies should focus on improving MNC to encourage more frequent use of surgery and might justify use of preoperative CRT over chemotherapy alone.

Combining stereotactic body radiation therapy with immunotherapy: current data and future directions

Stereotactic body radiation therapy (SBRT) offers excellent local control of early-stage non-small cell lung cancer (NSCLC), but there currently is a need for tolerable systemic therapy to address regional and distant disease progression. One potential option is immunotherapy, which in metastatic NSCLC has shown promise for sustained disease control in a subset of patients. There is also growing evidence for a clinical synergy between radiation and immunotherapy, with several ongoing trials studying the abscopal effect. This review summarizes the current data in the fast-changing field of immuno-radiation therapy, highlighting updates from recent clinical trials.

Emerging Therapies for Stage III Non-Small Cell Lung Cancer: Stereotactic Body Radiation Therapy and Immunotherapy

The current standard of care for locally advanced non-small cell lung cancer (NSCLC) includes radiation, chemotherapy, and surgery in certain individualized cases. In unresectable NSCLC, chemoradiation has been the standard of care for the past three decades. Local and distant failure remains high in this group of patients, so dose escalation has been studied in both single institution and national clinical trials. Though initial studies showed a benefit to dose escalation, phase III studies examining dose escalation using standard fractionation or hyperfractionation have failed to show a benefit. Over the last 17 years, stereotactic body radiation therapy (SBRT) has shown a high degree of safety and local control for stage I lung cancers and other localized malignancies. More recently, phase I/II studies using SBRT for dose escalation after conventional chemoradiation in locally advanced NSCLC have been promising with good apparent safety. Immunotherapy also offers opportunities to address distant disease and preclinical data suggest immunotherapy in tandem with SBRT may be a rational way to induce an “abscopal effect” although there are little clinical data as yet. By building on the proven concept of conventional chemoradiation for patients with locally advanced NSCLC with a subsequent radiation dose intensification to residual disease with SBRT concurrent with immunotherapy, we hope address the issues of metastatic and local failures. This “quadmodality” approach is still in its infancy but appears to be a safe and rational approach to the improving the outcome of NSCLC therapy.