Stereotactic body radiotherapy for centrally located stage I non-small cell lung cancer

Comparison of Treatment Outcomes Between Thoracoscopic Surgery and Stereotactic Body Radiotherapy for Early-Stage Non-Small Cell Lung Cancer

Objective: To compare the risk of death, tumor recurrence, metastasis, and disease progression in early-stage non-small cell lung cancer (NSCLC) patients treated with thoracoscopic surgery and stereotactic body radiotherapy (SBRT). Methods: Patients who underwent radical surgery and SBRT for NSCLC between April 2010 and November 2021 were retrospectively analyzed. Continuous and categorical variables were compared using the Mann-Whitney U and Chi-square test, respectively. Kaplan-Meier curves were used to evaluate the survival outcomes of each patient group. Cox proportional hazard regression analyses were performed to estimate the risk of death, tumor recurrence, metastasis, and disease progression. Results: A total of 167 patients were enrolled, of whom 75 and 92 underwent SBRT and surgery, respectively. The median follow-up was 45 months (range, 4-105 months). SBRT patients were observed to be significantly older (median, 76.0 vs 67.0 years; P < .001), and associated with significantly higher mortality rate (42.7% vs 26.1%, P = .024). However, no significant difference in overall survival duration was seen between the SBRT and surgery groups (45.0 vs 41.0 months; P = .199). SBRT patients demonstrated significantly lower rates of metastasis (12.0% vs 30.4%, P = .004), and significantly longer metastasis-free survival (39.0 months vs 35.5 months, P = .020). The remaining outcomes, including tumor recurrence and disease progression rates, were similar between the groups. Compared to surgery, SBRT did not significantly associate with death, recurrence, or disease progression. Kaplan-Meier curves showed significant differences in overall, tumor recurrence-free, and disease progression-free survival between the groups (log-rank P < .05). Conclusions: SBRT demonstrated similar overall survival compared to radical surgery, and associated with significantly reduced risk of tumor metastasis. Our study thereby suggests SBRT as the best treatment option for patients with inoperable NSCLC.

Utilization and Survival Impact of Hypofractionated Radiotherapy in Stage I Non-small Cell Lung Cancer

OBJECTIVES

The optimal fractionation schedule in unresected stage I non-small cell lung cancer (NSCLC) unsuitable for stereotactic body radiation therapy is unclear. Given the lack of comparative data regarding nonstereotactic body radiation therapy schemas, we compared overall survival (OS) with hypofractionated radiotherapy (HFRT) versus conventionally fractionated radiotherapy (CFRT) and examined the OS impact of different HFRT doses.

MATERIALS AND METHODS

This retrospective analysis included 2159 patients from the National Cancer Database diagnosed with stage I (cT1-2aN0M0) NSCLC between 2008 and 2016. Patients underwent CFRT (70≤BED10 [biologically effective dose] <100 Gy10 in ≥30 fractions), low-dose HFRT (LD-HFRT; 70≤BED10 [assuming α/β=10] <100 Gy10 in 11 to 24 fractions), or high-dose HFRT (HD-HFRT; 100≤BED10 ≤120 Gy10 in 6 to 10 fractions). Patients who received surgery, chemotherapy, or immunotherapy were excluded. We compared CFRT versus all HFRT, and separately CFRT versus LD-HFRT and CFRT versus HD-HFRT. OS was evaluated with the Kaplan-Meier estimator, log-rank test, and Cox regression.

RESULTS

A total of 63.2% of patients underwent CFRT, 23.5% LD-HFRT, and 13.3% HD-HFRT. OS was significantly longer with HFRT versus CFRT on univariable (28.2 mo [95% CI, 25.6-31.7] vs 26.4 mo [25.0-27.9]; log-rank=0.0025) but not multivariable analysis (MVA; hazard ratio [HR] 0.90; P=0.062). MVA yielded no significant difference in OS between CFRT and LD-HFRT (HR 0.96, P=0.53). OS was significantly longer with HD-HFRT versus CFRT on MVA (HR, 0.75; P=0.003). However, on sensitivity analysis using different multivariable modeling techniques, this did not retain statistical significance (HR, 0.83; P=0.12).

CONCLUSIONS

For stage I NSCLC, HFRT does not show a robust OS benefit compared with CFRT but may be preferred given the convenience and lower costs.

Fiducial markers for stereotactic lung radiation therapy: review of the transthoracic, endovascular and endobronchial approaches

Stereotactic body radiation therapy is an alternative to surgery for early-stage, inoperable peripheral non-small cell lung cancer. As opposed to linear accelerator (linac)-based (e.g. gating) and free-breathing techniques, CyberKnife® with Synchrony® technology allows accurate radiation delivery by means of a real-time respiratory motion tracking system using, in most cases, metal fiducial markers (FMs) placed in the vicinity of the target. The aims of this review are as follows. First, to describe the safety and efficacy of the transthoracic, endovascular and endobronchial FM insertion techniques for peripheral pulmonary lesions (PPLs). Second, to analyse performance in terms of the migration and tracking rates of different FM types. Recent developments in FM tracking for central lesions will also be reviewed. In conclusion, for PPLs, the endobronchial approach provides a low rate of pneumothorax, offers the possibility of concurrent diagnostic sampling for both the PPL and the lymph nodes, and, finally, reduces the intervention time compared to other techniques. In this context, coil-tailed and coil-spring FMs have shown the lowest migration rate with a consequently high tracking rate.

Stereotactic radiotherapy for soft tissue and bone sarcomas: real-world evidence

Introduction:

Selected patients with locally advanced or metastatic soft tissue and bone sarcomas (STBS) may benefit from intensive local treatment, such as stereotactic radiotherapy (SRT). This study aimed to summarize the utilization and outcomes of SRT in STBS and to identify predictive factors for progression and survival.

Materials and methods:

Consecutive patients with advanced STBS who underwent STBS in a sarcoma tertiary center were identified. We collected tumor- and treatment-related factors. Endpoints comprised time to local progression (TTLP), local progression-free survival (LPFS), time to progression, progression-free survival, and overall survival (OS). The Cox proportional-hazards model was used to identify prognostic factors.

Results:

We identified 141 patients who underwent 233 SRTs. Median follow-up was 21 months. Local and distant progression occurred after 19 and 163 SRTs, respectively. SRT for lung metastases was predictive for better TTLP and LPFS (hazard ratio, HR = 0.12, p = 0.007 and HR = 0.42, p = 0.002, respectively). Bone sarcoma (HR for TTLP = 3.18, p = 0.043; HR for LPFS = 1.99, p = 0.028) and lower administered dose (HR for TTLP = 0.98, p = 0.007; HR for LPFS = 0.99, p = 0.012) were predictive for worse TTLP and LPFS. SRT for oligometastases (HR = 0.46, p = 0.021) and lung metastases (HR = 0.55, p = 0.046) was predictive for better OS, whereas diagnosis of bone sarcoma (HR = 2.05, p = 0.029) was predictive for worse OS.

Conclusion:

SRT provides excellent local control in STBS patients without significant toxicity. Patients with oligometastatic disease, lung metastases, and soft tissue sarcomas benefit the most from SRT. The dose escalation moderately enhances local control; however, it does not translate into better survival.

Poly (ADP-ribose) polymerase inhibitors sensitize cancer cells to hypofractionated radiotherapy through altered selection of DNA double-strand break repair pathways

PURPOSE

Poly (ADP-ribose) polymerase inhibitors (PARPi) are known to induce radiosensitization. However, the exact mechanisms of radiosensitization remain unclear. We previously reported that PARPi may have a unique radiosensitizing effect to enhance β-components of the linear-quadratic model. The aim of this study was to evaluate PARPi in combination with high-dose-per-fraction radiotherapy and to elucidate the underlying mechanisms of its radiosensitization.

MATERIALS AND METHODS

Radiosensitizing effects of PARPi PJ34, olaparib, and veliparib were measured using a colony-forming assay in the human cancer cell lines, HCT116, NCI-H460, and HT29. Six different radiation dose fractionation schedules were examined by tumor regrowth assay using three-dimensional multicellular spheroids of HCT116, NCI-H460, SW620, and HCT15. The mechanisms of radiosensitization were analyzed by measuring DNA double-strand breaks (DSB), DNA damage responses, chromosomal translocations, cellular senescence, and cell cycle analysis.

RESULTS

Olaparib and PJ34 were found to show radiosensitization preferentially at higher radiation doses per fraction. Similar results were obtained using a mouse model bearing human tumor xenografts. A kinetic analysis of DNA damage responses and repairs showed that olaparib and PJ34 reduced the homologous recombination activity. However, a neutral comet assay showed that PJ34 treatment did not affect the physical rejoining of DNA-DSBs induced by ionizing radiation. Cell cycle analysis revealed that olaparib and PJ34 strikingly increased G1 tetraploid cells following irradiation, leading to premature senescence. The C-banding analysis of metaphase spreads showed that olaparib and PJ34 significantly increased ionizing radiation-induced dicentric chromosomes. The data suggests that PARPi olaparib and PJ34 altered the choice of DNA-DSB repair pathways rather than reducing the total amount of DNA-DSB repair, which resulted in increased repair errors. Increased quadratic misrepair was one of the mechanisms of PARP-mediated radiosensitization, preferentially at the higher dose range compared to the lower dose range.

CONCLUSION

PARPi may be a promising candidate to combine with stereotactic hypofractionated radiotherapy, aiming at high-dose region-directed radiosensitization.

Advances and controversies in the management of early stage non-small cell lung cancer

Complete resection continues to be the gold standard for the treatment of early-stage lung cancer. The landmark Lung Cancer Study Group trial in 1995 established lobectomy as the minimum intervention necessary for the management of early-stage non-small cell lung cancer, as it was associated with lower recurrence and metastasis rates than sublobar resection and lower postoperative morbidity and mortality than pneumonectomy. There is a growing tendency to perform sublobar resection in selected cases, as, depending on factors such as tumor size, histologic subtype, lymph node involvement, and resection margins, it can produce similar oncological results to lobectomy. Alternative treatments such as stereotactic body radiotherapy and radiofrequency ablation can also produce good outcomes in inoperable patients or patients who refuse surgery.

Lung Cancer Radiotherapy: Simulation and Analysis Based on a Multicomponent Mathematical Model

Background

Lung cancer has been one of the most deadly illnesses all over the world, and radiotherapy can be an effective approach for treating lung cancer. Now, mathematical model has been extended to many biomedical fields to give a hand for analysis, evaluation, prediction, and optimization.

Methods

In this paper, we propose a multicomponent mathematical model for simulating the lung cancer growth as well as radiotherapy treatment for lung cancer. The model is digitalized and coded for computer simulation, and the model parameters are fitted with many research and clinical data to provide accordant results along with the growth of lung cancer cells in vitro.

Results

Some typical radiotherapy plans such as stereotactic body radiotherapy, conventional fractional radiotherapy, and accelerated hypofractionated radiotherapy are simulated, analyzed, and discussed. The results show that our mathematical model can perform the basic work for analysis and evaluation of the radiotherapy plan.

Conclusion

It will be expected that in the near future, mathematical model will be a valuable tool for optimization in personalized medical treatment.

Dose and fractionation schedules in radiotherapy for non-small cell lung cancer

In the field of radiotherapy (RT), the issues of total dose, fractionation, and overall treatment time for non-small cell lung cancer (NSCLC) have been extensively investigated. There is some evidence to suggest that higher treatment intensity of RT, when given alone or sequentially with chemotherapy (CHT), is associated with improved survival. However, there is no evidence that the outcome is improved by RT at a higher dose and/or higher intensity when it is used concurrently with CHT. Moreover, some reports on the combination of full dose CHT with a higher biological dose of RT warn of the significant risk posed by such intensification. Stereotactic body radiotherapy (SBRT) provides a high rate of local control in the management of early-stage NSCLC through the use of high ablative doses. However, in centrally located tumors the use of SBRT may carry a risk of serious damage to the great vessels, bronchi, and esophagus, owing to the high ablative doses needed for optimal tumor control. There is a similar problem with moderate hypofractionation in radical RT for locally advanced NSCLC, and more evidence needs to be gathered regarding the safety of such schedules, especially when used in combination with CHT. In this article, we review the current evidence and questions related to RT dose/fractionation in NSCLC.

A nomogram for predicting the risk of lymph node metastasis in T1-2 non-small-cell lung cancer based on PET/CT and clinical characteristics

Background

Accurately predicting the risk level for a lymph node metastasis is critical in the treatment of non-small cell lung cancer (NSCLC). This study aimed to construct a novel nomogram to identify patients with a risk of lymph node metastasis in T1–2 NSCLC based on positron emission tomography/computed tomography (PET/CT) and clinical characteristics.

Methods

From January 2011 to November 2017, the records of 318 consecutive patients who had undergone PET/CT examination within 30 days before surgical resection for clinical T1–2 NSCLC were retrospectively reviewed. A nomogram to predict the risk of lymph node metastasis was constructed. The model was confirmed using bootstrap resampling, and an independent validation cohort contained 156 patients from June 2017 to February 2020 at another institution.

Results

Six factors [age, tumor location, histology, the lymph node maximum standardized uptake value (SUVmax), the tumor SUVmax and the carcinoembryonic antigen (CEA) value] were identified and entered into the nomogram. The nomogram developed based on the analysis showed robust discrimination, with an area under the receiver operating characteristic curve of 0.858 in the primary cohort and 0.749 in the validation cohort. The calibration curve for the probability of lymph node metastasis showed excellent concordance between the predicted and actual results. Decision curve analysis suggested that the nomogram was clinically useful.

Conclusions

We set up and validated a novel and effective nomogram that can predict the risk of lymph node metastasis for individual patients with T1–2 NSCLC. This model may help clinicians to make treatment recommendations for individuals.

[Efficacy of Stereotactic Body Radiotherapy versus Surgery for the Treatment of Early Non-small Cell Lung Cancer: A Meta-analysis]

BACKGROUND

To compare the clinical efficacy of stereotactic body radiotherapy (SBRT) versus surgery for early-stage non-small cell lung cancer through evidence based medicine analysis.

METHODS

A systematic search was performed in the PubMed, EMBASE, CNKI and Wan Fang databases to find studies published before June 2020. Two authors independently extracted the data and assessed the eligibility. All of the statistical analyses were performed using Stata 13.0. Subgroup analysis were performed according to the score matching study and operation type (lobectomy, segmentectomy and thoracoscopic assisted surgery).

RESULTS

Finally, 14 articles were included, including 15,841 cases in SBRT group and 17,708 cases in operation group. 10 articles used propensity score matching methods for survival analysis. Thirteen were retrospective cohort studies and one was randomized controlled trial. The results of meta-analysis showed that the overall survival rate of the surgery group and the SBRT group was statistically significant. The overall survival rate of the SBRT group (HR=1.51, 95%CI: 1.31-1.74) was inferior to that of the surgery group. In the subgroup analysis of the surgical type, there was no statistical difference between the SBRT group and each surgical type. The difference of overall survival rate between SBRT group and surgery group was statistically significant (HR=1.66, 95%CI: 1.45-1.90) in studies of propensity score matching. There was no statistically significant difference in cancer-specific survival between the surgery and SBRT groups (HR=1.12, 95%CI: 0.83-1.52).

CONCLUSIONS

The overall survival rate of surgical treatment is better than that of SBRT, but it has no obvious advantages in cancer specific survival rate.

The CT appearance pattern of radiation-induced lung injury and tumor recurrence after stereotactic body radiation therapy in early stage non-small cell lung cancer

Background

Radiographic changes after stereotactic body radiation therapy (SBRT) have not been well studied. The purpose of this study was to investigate the computed tomography (CT) appearance pattern of radiation-induced lung injury (RILI) and recurrence after SBRT in patients with early stage non-small cell lung cancer (NSCLC).

Methods

We retrospectively analyzed clinical data of inoperable early stage NSCLC patients undergoing SBRT treatment from February 2012 to June 2018. All patients had undergone serial CT scanning before SBRT and after completion of SBRT. An experienced radiation oncologist and radiologist reviewed all CT images, and identified the RILI and CT high-risk features (HRFs).

Results

A total of 60 patients were enrolled in this study; 55 patients had RILI (91.67%) and 7 patients had local failure. In the early CT findings of observers 1 and 2, there were diffuse ground glass opacities (GGOs) in 3 and 4 patients, diffuse consolidation in 10 and 12 patients, patchy consolidation in 22 and 15 patients, patchy GGOs in 19 and 24 patients, and no changes in 5 and 4 patients, respectively (kappa =0.706). In the late CT findings of observer 1 and 2, there were modified conventional patterns in 37 and 37 patients, mass-like patterns in 10 and 9 patients, scar-like patterns in 7 and 8 patients, and no changes in 5 and 5 patients, respectively (kappa =0.726). In the results of the CT-based HRFs of disease local failure, there were ≥1 HRFs in 7 patients, ≥2 HRFs in 7 patients, ≥3 HRFs in 6 patients, ≥4 HRFs in 5 patients, and ≥5 HRFs in 3 patients, respectively. Patients with only 1 HRF showed high sensitivity (100%) and low specificity (52.80%), with the specificity increasing and the sensitivity decreasing as the number of HRFs increased.

Conclusions

The agreement of the CT appearance on RILI between 2 observers was good. Regular follow-up and attention to HRFs are vital for better identifying RILI and local disease failure.

Accelerated hypofractionated radiotherapy with concurrent full dose chemotherapy for locally advanced non-small cell lung cancer: A phase I/II study

INTRODUCTION

We report the results of toxicity and survival in stage III NSCLC patients treated with concurrent accelerated hypofractionated AHRT-CHT within a prospective study.

METHODS

92 patients received 3D-CRT or IMRT-planned RT: 58.8 Gy /21 fractions (2.8 Gy/fraction, 4 weeks) with 2 cycles of CHT (Cisplatin 80 mg/m² D1 and D22; and Vinorelbine 25 mg/m², D1, D8, D22, and D29) started with D1 of RT. Non-hematological toxicity was evaluated using RTOG-EORTC criteria, every week during treatment, one month after treatment completion, and every three months thereafter.

RESULTS

Two patients did not receive the prescribed RT dose; 22 (24%) received only one CHT cycle. Median follow-up was 21.5 months (range: 1-65) for all patients and 32 months (range: 8-65) for living patients. There were: 13 (14%) cases of grade ≥III acute esophageal toxicity; 3 grade III acute pneumonitis, and 2 grade III late pulmonary toxicities. Two toxic deaths occurred within 3 months after treatment: fatal hemoptysis (1) and complications of esophageal toxicity (1). Five other deaths that occurred within one year after treatment were probably treatment-related: lung abscess (1), fatal hemoptysis (2), death from undetermined cause (2). Median overall survival was 38 months (95%CI:27-49), median progression free survival was 25 months (95%CI:14-36).

CONCLUSIONS

Survival rates are encouraging, but the observed rate of toxic and probably toxic deaths is of potential concern. We proceed with the use of AHRT with concomitant full dose CHT, but patients with large PTV and major vascular abutment are excluded due to potentially increased risk of toxic death.