Survival Outcomes of RFA, SBRT, or Sublobar Resection for Patients with Clinical Stage I NSCLC

Survival Outcomes of Treatment with Radiofrequency Ablation, Stereotactic Body Radiotherapy, or Sublobar Resection for Patients with Clinical Stage I Non–Small-Cell Lung Cancer: A Single-Center Evaluation

Clinical question
Is there a difference in outcome of patients with stage I non-small cell lung cancer (NSCLC) who underwent either radiofrequency (RF) ablation, stereotactic body radiotherapy (SBRT), or sub-lobar resection (SLR)?

Take-away point
SLR achieved the longest survival. However, after statistical adjustment, there were no significant outcome differences in over all survival (OS) and progression-free survival (PFS) among the treatment groups except in 1 model. RF ablation or SBRT may be used as alternative treatments in select patients with early stage NSCLC.

Reference
Iguchi T, Hiraki T, Matsui Y, et al. Survival Outcomes of Treatment with Radiofrequency Ablation, Stereotactic Body Radiotherapy, or Sublobar Resection for Patients with Clinical Stage I Non-Small-Cell Lung Cancer: A Single-Center Evaluation. J Vasc Interv Radiol. 2020;31(7):1044-1051.

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Study design
Retrospective, single center

Funding Source
None reported.

Setting
Academic Hospital, Okayama, Japan.

Summary

A retrospective study which compared the 5 year overall and progression free survival rate of 289 patients with stage I NSCLC who underwent SLR (n=193), or either RF ablation (n=38) or SBRT (n=58), when they refused surgery or were deemed poor surgical candidates. Patients in the SLR grouped achieved the longest OS and PSF according to Kaplan-Meier curves. However after propensity score correction, there were no significant differences in either OS (P=0.701) or PSF (P=0.091) rates based on the Kaplan-Meier curves.

The reported survival rates of the SLR group were longer compared to the RF and SBRT groups. The 5 year OS of RF ablation, SBRT, and SLR were 25% to 61%, 25% to 83%, and 60.5% to 89.6% respectively. The median survival time of RF ablation, SBRT, and SLR were 29 to 67 months, 39-62 months, and not reached or 7.8 years, respectively. The median hospital stays for RF ablation, SBRT, and SLR were 6.5, 6, and 16 days, respectively. No adverse events (AEs) of grade 3 or higher occurred in either RF ablation or SBRT groups compared to the eight grade 3 and three grade 4 AEs with in the SLR group.

The results of this study further emphasized that RF ablation or SBRT may be used as alternative methods of treatment in select patients with early stage NSCLC.

Commentary

The increased utilization of CT imaging has led to earlier diagnosis of primary lung cancer, and where reduction surgery (such as SLR) has been the treatment of choice for small, localized and peripheral lesions. Some patients – the elderly, those with end-organ disease and medical comorbidities – are not good surgical candidates. RF ablation and SBRT are alternative treatments with shorter hospitalizations and comparable survival rates to that of surgery. The main limitations in this study were the retrospective design, small cohort, single center, and irregularity of follow up protocols. Additionally, there were missing PF testing data (one of the 14 independent variables used to calculate the propensity score), especially among the RF ablation group, although the authors did identify FEV1 as a confounding variable after hazard models were adjusted. Selection bias for stratification was also identified, as, for example, patients with interstitial pneumonia are known to be ill suited for RFA or SBRT treatment. Other factors, such as insurance coverage, amenability to repeat treatment, and tumor characteristics, should be considered, as they can impact the appropriateness of each procedure. However, large, multi-centered randomized controlled trials could better compare these interventions in the future.

Post Author
Ashkan Berenji, DO
Diagnostic and ESIR Resident, PGY-3
Baylor College of Medicine
@BerenjiAshkan

70- to 150-mm Radiopaque Spherical Embolics for PAE

Use of 70- to 150-mm Radiopaque Spherical Embolics for Prostatic Artery Embolization

Clinical question
To describe the use of radiopaque spherical embolics for PAE in treating lower urinary tract symptoms secondary to BPH

Take away point
PAE with 70- 150-mm radiopaque spherical embolics are safe and effective for treating lower urinary tract symptoms secondary to BPH

Reference
Maron, S. Z., et al. (2020). "Use of 70- to 150- mm Radiopaque Spherical Embolics for Prostatic Artery Embolization." Journal of Vascular and Interventional Radiology 31(7): 1084-1089.

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Study design
Retrospective

Funding Source
None

Setting
Academic hospital, Department of Radiology, Icahn School of Medicine at Mount Sinai, Mount Sinai Hospital, New York





Figure 4. Axial and coronal cone-beam CT of left-sided distribution of microspheres. (a) Axial cone-beam CT performed immediately after bilateral PAE (the left side was treated first) demonstrates predominantly left-sided distribution of 70- to 150-μm radiopaque mi- crospheres in the prostate gland (arrow). (b) Coronal cone-beam CT performed immediately after bilateral PAE (left side was treated first) demonstrates predominantly left-sided distribution of 70- to 150-μm radiopaque microspheres in the prostate gland (arrow).

Summary

Prostatic artery embolization (PAE) is effective for treating lower urinary tract symptoms (LUTS) of benign prostatic hyperplasia (BPH), however previous studies have described clinical failure rates up to 25%. The authors investigated the effectiveness of 70- 150-mm radiopaque microspheres for PAE. The 70- 150-mm spheres have intrinsic radiopacity allows visualization of the embolic distribution and a more targeted embolization. Additionally, the 70- 150-mm may provide additional clinical benefit due to a deeper embolization.

The authors reviewed 21 patients who underwent bilateral PAE with 70- 150-mm radiopaque spherical embolics over the course of one year. Of the 21 patients, 6 had indwelling urinary catheters and 2 required intermittent self-catheterization. The primary outcome was evaluated using the International Prostate Symptom Score (IPSS), quality of life score (QOL), and International Index of erectile function 5 questionnaire (IIEF-5). The prostate size was assessed with MRI at 6 months.

Technical success, defined by stasis in both prostatic arteries and direct visualization of the treated area on cone-beam CT, was 81% (17/21). 4 cases could not be embolized bilaterally due to tortuosity and atherosclerotic disease. 19/21 patients had transradial access and 2/21 received transfemoral access. The mean total embolic used was 6.5 mL. Non-target embolization was identified in 2 cases. 4 of 6 patients with indwelling catheters were able to remove their catheters at an average of 42 days post procedure. Neither patient requiring intermittent catheterization was able to progress to spontaneous voiding. Reported adverse events included dysuria, pelvic pain, hematospermia, and hematuria. One major complication was because of E coli urosepsis, however, was thought to be unrelated to PAE. Of the 2 cases of non-target embolization, 1 experienced hematospermia and 1 was asymptomatic.

The clinical response was positive at 1 and 2 months follow up, with improvement observed in QOL (-2 ± 1.2), IPSS (10.6 ± 7.6), and IIEF (9.3 ± 4.1) scores. The rate of successful urinary catheter removal was 67%. The prostate volume decreased by a mean of 28 ± 16.2 g at 6 months.

Commentary

The authors retrospectively reviewed 21 patients who received bilateral PAE with 70- 150-mm radiopaque spheres. The radiopaque spheres provide direct visualization of the embolized area on cone beam CT and allow for assessment of non-target embolization. Improvements in QOL, IPSS, and IIEF scores are promising, and the clinical results from this study are comparable to results from previous PAE meta-analyses. The theory that smaller embolics may produce further clinical benefit is intriguing. However, further evaluation with a larger sample size and additional analysis of Qmax, post-void residual volume, and PSA would be helpful to better characterize the potential advantages. Although the published complication rate from non-target embolization is low, the risk exists and the inherent radiopacity may better evaluate and highlight this. The authors, however, described difficulty differentiating the radiopaque embolic from retained contrast. This review presents an interesting peek into possible improvements for PAE, however more extensive investigation is needed to further characterize the benefits of 70- 150-mm radiopaque spherical embolics.

Post Author
Maxwell Cretcher, D.O.
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Dotter Interventional Institute, Oregon Health and Science University
@MCretcher

Y-90 Treatment of Pancreatic Cancer Patients with Liver-Dominant Metastatic Disease

Transarterial Radioembolization Treatment of Pancreatic Cancer Patients with Liver-Dominant Metastatic Disease using Yttrium-90 Glass Microspheres: A Single-Institution Retrospective Study

Clinical question
How safe and efficacious is transarterial radioembolization (TARE) with yttrium-90 (90Y)-labeled glass microspheres in pancreatic adenocarcinoma patients with liver-dominant metastatic disease?

Take-away point
TARE with 90Y-labeled glass microspheres is safe with promising overall survival (OS) in liver-dominant metastatic pancreatic cancer.

Reference
Transarterial Radioembolization Treatment of Pancreatic Cancer Patients with Liver-Dominant Metastatic Disease using Yttrium-90 Glass Microspheres: A Single-Institution Retrospective Study. Kayaleh, R et al. Journal of Vascular and Interventional Radiology, Volume 31, Issue 7, 1060-1068.

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Study design

Retrospective review

Funding source

Self-funded or unfunded

Setting

Single institution

Summary

There have been a limited number of studies evaluating the feasibility of Y90 treatment for liver-dominant metastatic pancreatic adenocarcinoma, with much of the work to date focusing on use of resin microspheres. The authors of this study investigated the role of glass microspheres for treatment of liver-dominant metastatic pancreatic adenocarcinoma.

This was a retrospective review of 26 patients with liver-dominant metastatic pancreatic adenocarcinoma treated over a 7 year period at the authors’ institution. Of these 26 patients, eight patients underwent surgical resection of the primary pancreatic cancer; 7 patients had pancreaticoduodenectomy; and 1 patient had distal pancreatectomy. There was a median interval of 17.7 months between diagnosis and TARE treatment. At the time of TARE treatment, 14 patients had multiple liver metastases (≥2); of these, 11 had bilobar disease. Nineteen patients had extrahepatic disease. All patients received systemic chemotherapy before TARE, and 19 received systemic therapy after TARE. Median time between TARE treatment and adjuvant chemotherapy was 22 days (chemotherapy consisted of 5-flurouracil/leucovorin ± irinotecan ± oxaliplatin and gemcitabine-based chemotherapy). TARE was performed using 90Y-labeled glass microspheres. In patients with bilobar disease, the left and right lobes were treated separately, approximately 4–6 weeks apart, except for 2 patients who had the left and right lobe treated at the same time.

Nineteen patients received 1 TARE treatment; 5 patients received 2 treatments (3 of these patients had bilobar disease and 2 had unilobar disease); 1 patient received 3 treatments; and 1 patient received 4 treatments. The average delivered dose was 137.6 ± 27.6 Gy (range, 105–380 Gy). The median OS from pancreatic adenocarcinoma diagnosis was 33.0 months, the median OS from diagnosis of liver metastasis was 21.8 months, and the median OS from TARE treatment was 7.0 months. The median hepatic PFS was 2.7 months. Interestingly, a statistically significant association was found showing that patients with solitary liver metastasis had a lower median OS than patients with multiple liver metastases. There were 42 episodes of grade 1–2 clinical adverse events and 3 episodes of grade 3 clinical adverse events. The MELD score was not significantly different at the 3-month follow-up than the baseline score before TARE. Baseline and follow-up imaging at 3 months were available for 22 of 26 patients, which showed partial response in 1 patient (4.5%), stable disease in 9 patients (40.9%), and progressive disease in 12 patients (54.5%), with a disease control rate (partial response + stable disease) of 45%.

Commentary

Pancreatic cancer remains a leading cause of cancer-related death. The only curative therapy is surgical resection, however, a minority of patients are viable surgical candidates and, even after surgery, there is a high rate of recurrence. In addition, a majority of patients initially present with metastatic disease. TARE is effective in achieving local control in a variety of different tumor types and there has been some work to date, albeit limited, evaluating its role in treatment of liver-dominant metastatic pancreatic adenocarcinoma. This study is the first to demonstrate the role of 90Y-labeled glass microspheres in the treatment of metastatic pancreatic cancer patients. The authors showed that treatment was well-tolerated with low toxicity with OS similar to that of surgical resection of hepatic metastases. Therefore, TARE may be an attractive option when compared to surgery for patients with advanced disease. Larger, prospective studies are anticipated with interest for validation of these findings.

Post Author:
Zagum Bhatti, MD
Assistant Professor
Department of Radiology, Interventional Radiology Division
University of Texas Health Science Center at Houston, Houston, TX
@ZagumBhatti