Sinoatrial Node Dose Is Associated With Worse Survival in Patients Undergoing Definitive Stereotactic Body Radiation Therapy for Central Lung Cancers

PURPOSE

Our purpose was to evaluate the clinical consequences of sinoatrial node (SAN) and atrioventricular node (AVN) irradiation in patients undergoing stereotactic body radiation therapy (SBRT) for central non-small cell lung cancer (NSCLC) tumors.

METHODS AND MATERIALS

A single-institutional retrospective review of patients with primary NSCLC undergoing definitive SBRT for centrally located thoracic tumors from February 2007 to December 2021 was performed. The SAN and AVN were contoured in accordance with a published contouring atlas, and the maximum dose (Dmax) and mean dose (Dmean) for each structure were calculated. Sequential log rank testing between the 50th and 90th percentiles was used to identify potential cutoff values for the corresponding dosimetric parameters and overall survival.

RESULTS

Among 93 eligible patients, the median age was 72.5 years (IQR, 66.6-78.3), and median follow-up was 32.4 months (IQR, 13.0-49.6). The median SAN Dmax and Dmean were 95 cGy (range, 9-5394) and 58 cGy (range, 7-3168), respectively. The median AVN Dmax and Dmean were 45 cGy (range, 4-2121) and 34 cGy (range, 3-1667), respectively. Candidate cutoff values for SAN Dmax and Dmean were 1309 and 836 cGy, respectively. No associations between AVN parameters and survival outcomes were identified. Upon multivariate Cox regression, the SAN Dmax cutoff (hazard ratio [HR], 2.03 [1.09-3.79]; P = .026) and SAN Dmean cutoff (HR, 2.22 [1.20-4.12]; P = .011) were significantly associated with overall survival. For noncancer-associated survival, the SAN Dmax cutoff trended toward significance (HR, 2.02 [0.89-4.57]; P = .092), and the SAN Dmean cutoff remained significantly associated (HR, 2.34 [1.05-5.18]; P = .037).

CONCLUSIONS

For patients undergoing SBRT for NSCLC, SAN Dmax and Dmean were significantly associated with worse overall survival using cut-off values of 1309 and 836 cGy, respectively. Further studies examining the effect of SAN irradiation during SBRT are warranted.

Long-Term Survival and Failure Outcomes of Single-Fraction Stereotactic Body Radiation Therapy in Early Stage NSCLC

Introduction

This study aims to report our 13-year institutional experience with single-fraction stereotactic body radiation therapy (SF-SBRT) for early stage NSCLC.

Methods

A single-institutional retrospective review of patients with biopsy-proven peripheral cT1-2N0M0 NSCLC undergoing definitive SF-SBRT between September 2008 and May 2022 was performed. All patients were treated to 27 Gy with heterogeneity corrections or 30 Gy without. Primary outcomes were overall survival and progression-free survival. Secondary outcomes included local failure, nodal failure, distant failure, and second primary lung cancer.

Results

Among 263 eligible patients, the median age was 76 years (interquartile range [IQR]: 70-81 y) and median follow-up time was 27.2 months (IQR: 14.25-44.9 mo). Median tumor size was 1.9 cm (IQR: 1.4-2.6 cm), and 224 (85%) tumors were T1. There were 92 patients (35%) alive at the time of analysis with a median follow-up of 34.0 months (IQR: 16.6-50.0 mo). Two- and five-year overall survival was 65% and 26%, respectively. A total of 74 patients (28%) developed disease progression. Rates of five-year local failure, nodal failure, distant failure, and second primary lung cancer were 12.7%, 14.7%, 23.5%, and 12.0%, respectively.

Conclusions

Consistent with multiple prospective randomized trials, in a large real-world retrospective cohort, SF-SBRT for peripheral early stage NSCLC was an effective treatment approach.

Pancreas Cancer Learning Health Network Established to Share Best Practice Across 14 Centers and Improve Patient Outcomes

PURPOSE/OBJECTIVE(S)

Pancreas cancer (PC) survival is among the lowest of all malignancies. Clinical trials have failed to significantly improve outcomes. Individual and institutional biases in care result in significant variation in practice, further hindering progress. Learning health networks (LHNs) prospectively collect real world data across centers and test improvements that can rapidly be expanded across centers if deemed successful. Herein, we report preliminary progress from the Pancreas Cancer Canopy Cancer Collective (PC-CCC), the first oncology LHN, established to improve duration and quality of survival in PC.

MATERIALS/METHODS

In 2019, we established the PC-CCC with six care centers who engaged in a collaborative design process to create a set of improvement aims, change ideas, and outcome measures. Center team members receive training and coaching in collaborative quality improvement methods, applied to local improvement efforts. Eight more centers joined in 2021, and a shared Canopy outcomes database was built and implemented to inform center-specific and network-wide improvement efforts and allow the LHN to undertake research using real-world data. Current improvement efforts are focused on proactively screening new PC patients for: (1) Clinical trials, (2) pancreas enzymes, (3) palliative care needs, and (4) goals of care conversations.

RESULTS

Currently, 14 care centers are active participants in the PC-CCC LHN. Data on a total of 2,002 PC patients are available to date. At presentation to the care center, most patients are female (51%) and have biopsy proven PC (83.9%). Average age is 68 years, and presenting disease status is metastatic (14.5%), resectable (11.4%), locally advanced (10.9%), borderline resectable (8.1%), or not yet staged (40%). For those who received radiation, 75.8% received stereotactic body radiation therapy. Among patients whose chemotherapy regimen was documented, most received 5-fluorouracilbased treatment (52%). Descriptive follow up data (including treatment and outcomes) are being actively updated, to be reported at time of presentation.

CONCLUSION

Creation of a cancer LHN for PC is feasible and has set the stage for improving patient and provider outcomes through iterative community-building, continuous improvement, and sharing of data and multidisciplinary best practices. Additionally, the data obtained from the CCC database can rapidly inform the network how variation in clinical practice across centers can influence outcomes.

Sinoatrial Node Irradiation in Patients Undergoing Definitive Stereotactic Body Radiation Therapy (SBRT) for Central Lung Cancers

PURPOSE/OBJECTIVE(S)

The clinical consequences of sinoatrial node (SAN) and atrioventricular node (AVN) irradiation in patients undergoing thoracic stereotactic body radiation therapy (SBRT) remains unclear. We examined the relationship between SAN and AVN dose with survival outcomes in patients with central non-small cell lung cancer (NSCLC) tumors.

MATERIALS/METHODS

A single-institutional retrospective review of patients with primary NSCLC undergoing definitive SBRT for centrally located tumors from February 2007 to December 2021 was performed. Central tumors were defined as within 2 cm of the proximal airway, mediastinum, great vessels, or spinal cord whereas ultracentral tumors were directly abutting any of the above structures. All patients underwent five-fraction SBRT to a total dose of 50 to 60 Gy. The SAN and AVN were contoured in accordance with a published contouring atlas and the maximum dose (Dmax) and mean dose (Dmean) for each structure were calculated. Sequential log rank testing between the 50th and 90th percentiles was used to identify potential cutoff values for the corresponding dosimetric parameters and non-cancer associated survival.

RESULTS

Among 93 eligible patients, the median age was 72.5 years (Inter-Quartile Range [IQR], 66.6-78.3), median follow up was 32.4 months (IQR, 13.0-49.6), and 48 patients were female (52%). There were 49 ultracentral tumors (53%) and the median planning target volume (PTV) was 31.0 cc (IQR, 18.0-53.3). The median SAN Dmax and Dmean were 95 cGy (IQR, 37-1,072) and 58 cGy (IQR, 26-641), respectively. The median AVN Dmax and Dmean were 45 cGy (IQR, 19-506) and 34 cGy (IQR, 15-160), respectively. Candidate cutoff values for SAN Dmax and Dmean were 1,309 cGy and 814 cGy, respectively. No significant cutoff values were identified for either AVN parameter. Kaplan-Meier analysis for the proposed SAN Dmean constraint was significantly associated with overall (p = 0.016) and non-cancer associated survival (p = 0.028). The SAN Dmax constraint was significantly associated with only overall survival (p = 0.029). In a multivariate model, the SAN Dmean cutoff significantly correlated with both overall (Hazard Ratio [HR] 2.1 [1.13-3.78], p = 0.019) and non-cancer associated survival (HR 2.39 [1.12-5.10], p = 0.025) whereas the SAN Dmax cutoff was only significantly associated with overall survival (HR 1.95 [1.03-3.68], p = 0.041).

CONCLUSION

SAN Dmax and Dmean were associated with significantly worse overall survival using cut-off values of 1,309 cGy and 814 cGy, respectively. SAN dose should be considered in radiation planning and further study on the consequence of SAN irradiation during SBRT is warranted.

Association of neutrophil-lymphocyte ratio with survival in peripheral early-stage non-small cell lung cancer after stereotactic body radiation therapy

BACKGROUND

The role of neutrophil-lymphocyte ratio (NLR) as a predictor for survival in single fraction SBRT-treated non-small cell lung cancer (NSCLC) patients remains unclear. We performed an observational cohort study to determine the role of pretreatment NLR in predicting survival of early-stage NSCLC patients after single fraction SBRT.

METHODS

A single-institution database of peripheral early-stage NSCLC patients treated with SBRT from February 2007 to May 2022 was queried. Optimal threshold of neutrophil-lymphocyte ratio (NLR) was defined based on maximally selected rank statistics. Cox multivariable analysis (MVA), Kaplan-Meier, and propensity score matching were performed to evaluate outcomes.

RESULTS

A total of 286 patients were included for analysis with median follow up of 19.7 months. On Cox multivariate analysis, as a continuous variable, NLR was shown to be an independent predictor of OS (adjusted hazards ratio [aHR] 1.06, 95% CI 1.02-1.10, p = 0.005) and PFS (aHR 1.05, 95% CI 1.01-1.09, p = 0.013). In addition, NLR was associated with DF (aHR 1.11, 95% CI 1.05-1.18, p < 0.001). Maximally selected rank statistics determined 3.28 as the cutoff point of high NLR versus low NLR. These findings were confirmed upon propensity matching.

CONCLUSIONS

Pretreatment NLR is an independent predictor for survival outcomes of peripheral early-stage NSCLC patients after single fraction SBRT.

Brachial Plexopathy After Single-Fraction Stereotactic Body Radiation Therapy in Apical Lung Tumors

PURPOSE

The objective of this study was to evaluate the incidence of brachial plexus injury (BPI) after single-fraction stereotactic body radiation therapy (SBRT) to apical lung tumors.

METHODS AND MATERIALS

A retrospective cohort analysis was performed of all patients treated with single-fraction lung SBRT at our institution from 2007 to 2022. Apical tumors were identified as those with an epicenter located above the arch of the aorta. Dosimetric analysis of dose to the brachial plexus (BP) was done using both the subclavian vessel (SCV) surrogate structure and anatomic BP. BPI was assessed per Common Terminology Criteria for Adverse Events, version 4.0, as regional paresthesia, marked discomfort and muscle weakness, and limited movement of the arm or hand.

RESULTS

A total of 45 patients met inclusion criteria with median follow-up of 21 months. There were 9 patients who exceeded the BP dose constraint using the SCV or anatomic BP volume. Only 1 patient (2.2%) developed grade 2 BPI, occurring 7 months after SBRT. Dose to the anatomic BP for the affected patient was 26.39 Gy. For the entire cohort, the median SCV and anatomic maximum BP doses were 8.44 and 7.14 Gy, respectively.

CONCLUSIONS

There is considerable variability in dose delivered to the BP after SBRT to apical lung tumors. BPI after single-fraction SBRT to apical tumors is rare and rates are comparable with those reported with multifraction regimens.

Change in CA 19-9 levels after chemoradiotherapy predicts survival in patients with locally advanced unresectable pancreatic cancer

PURPOSE

RTOG 9704 demonstrated a prognostic role for postoperative CA 19-9 in patients with resectable pancreatic carcinoma following surgery. Our study aimed to investigate whether CA 19-9 provided similar prognostic information in patients with locally advanced unresectable pancreatic cancer (LAPC) treated with chemoradiotherapy (CRT) and to determine whether such endpoints should therefore be reported in future randomized trials.

METHODS AND MATERIALS

Between December 1998 and October 2009, 253 patients with LAPC were treated with 5-fluourouracil-based concurrent CRT at our institution. Median radiation dose was 50.4 Gy. Only patients with a bilirubin of less than 2 mg/dL at the time the CA 19-9 was evaluated were included in the analysis to avoid the confounding effect of hyperbilirubinemia. Of the eligible patients, 54 had pre and post CRT CA 19-9 values available. The median age was 68 years and 52% were female. Categorized versions of the first post-CRT CA 19-9 were tested in 50 point increments beginning at <50 to >1,000 and percent change in pre to post-CRT CA 19-9 using cut points of 10% increments from <0% (increased) to >90%. Survival was measured from the date of first post CRT CA 19-9 level until death or last follow-up. Univariate and multivariate statistical methodologies were used to determine significant prognostic factors for overall survival.

RESULTS

Median CA 19-9 prior to CRT was 363 U/mL and post CRT median was 85.5 U/mL. Following CRT, patients with a decrease of >90% from their baseline CA 19-9 level had a significantly improved median survival than those that did not (16.2 vs. 7.5 months, P=0.01). The median survival of patients with a CA 19-9 level lower than the median post CRT value was 10.3 months, compared with 7.1 months for those with a CA 19-9 level greater than the median (P=0.03). Post CRT CA 19-9 less than 50 U/mL and histologic grade I-II also showed prognostic significance (both P=0.03). In multivariate analysis, post CRT CA 19-9 less than the median level of 85.5 U/mL was an independent prognostic factor for overall survival (HR 0.34; 95% CI, 0.13-0.85, P=0.02).

CONCLUSIONS

Our results indicate that post treatment CA 19-9 is predictive for overall survival in patient with LAPC following CRT. We recommend that pre and post treatment CA 19-9 levels be obtained in patients receiving CRT and that these values be considered for prognostic nomograms and future clinical trials.

Treatment of locally advanced unresectable pancreatic cancer: a 10-year experience

PURPOSE

We retrospectively analyzed the results of patients with locally advanced unresectable pancreatic cancer (LAPC) treated with either chemoradiation (CRT) or chemotherapy alone over the past decade.

METHODS AND MATERIALS

Between December 1998 and October 2009, 116 patients with LAPC were treated at our institution. Eighty-four patients received concurrent chemoradiation [RT (+) group], primarily 5-flourouracil based (70%). Thirty-two patients received chemotherapy alone [RT (-) group], the majority gemcitabine based (78%). Progression-free survival (PFS) and overall survival (OS) were calculated from date of diagnosis to date of first recurrence and to date of death or last follow-up, respectively. Univariate statistical analysis was used to determine significant prognostic factors for overall survival.

RESULTS

Median patient age was 67 years. Sixty patients were female (52%). Median follow-up was 11 months (range, 1.6-59.4 months). The RT (+) group received a median radiation dose of 50.4 Gy, was more likely to present with ECOG 0-1 performance status, and experienced less grade 3-4 toxicity. PFS was 10.9 versus 9.1 months (P=0.748) and median survival was 12.5 versus 9.1 months (P=0.998) for the RT (+) and RT (-) groups respectively (P=0.748). On univariate analysis, patients who experienced grade 3-4 toxicity had worse overall survival than those who did not (P=0.02).

CONCLUSIONS

Optimal management for LAPC continues to evolve. Patients who developed treatment-related grade 3-4 toxicity have a poorer prognosis. Survival rates were not statistically significant between chemotherapy and chemoradiotherapy groups.