Synchronous percutaneous core-needle biopsy and microwave ablation for stage I non-small cell lung cancer in patients with Idiopathic pulmonary fibrosis: initial experience

Abstract Purpose This study aimed to retrospectively evaluate the safety and feasibility of computed tomography (CT)-guided synchronous percutaneous core-needle biopsy (CNB) and microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) in patients with idiopathic pulmonary fibrosis (IPF). Methods From January 2019 to January 2023, nineteen stage I NSCLC patients with IPF underwent CT-guided synchronous percutaneous CNB and MWA in this study. The technical success rate, complications, local tumor progression (LTP) and overall survival (OS) were observed, and the effect of synchronous percutaneous CNB and MWA were evaluated. Results The technical success rate of synchronous percutaneous CNB and MWA was 100%. With a median follow-up time of 20.36 months, the median OS was 25 months (95% CI: 21.79, 28.20). The six-, twelve- and eighteen-month OS rates were 94.73%, 89.47% and 57.89%, respectively. The six-, twelve- and eighteen-month LTP rates were 0%, 10.52% and 31.57%, respectively. Major complications including pneumothorax, bronchopleural fistula and pneumonia occurred in 26.32% (5/19) patients. None of the patients died during the procedure. Conclusions According to the results of the current study, CT-guided synchronous percutaneous CNB and MWA appears to be a safe and effective for stage I NSCLC in patients with IPF and providing an alternative therapeutic option for local control of pulmonary malignancy in high-risk patients.


Introduction
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, interstitial fibrosing lung disease with a median survival of less than 3-5 years following diagnosis [1].It is characterized by progressive deterioration in dyspnea and pulmonary function, with a poor prognosis [2].Some previous studies have suggested that patients with IPF have an increased risk of developing lung cancer, mainly related to their long-term treatment with glucocorticoids and immunosuppressants [3-5].In addition, most of patients with IPF have a history of heavy smoking, which further contributes to carcinogenesis [6].Lung cancer remains the leading cause of cancer death and its incidence is increasing, with non-small cell lung cancer (NSCLC) accounting for approximately 85% of the diagnoses [7].Stage I NSCLC tends to be neglected in the clinic, especially in combination with IPF.The gold standard for its treatment is wedge resection or segmental resection with lymph node dissection.Pirfenidone or nintedanib plus chemotherapy or immune checkpoint inhibitors (ICIs) may be a safe first-line therapy for NSCLC with IPF in previous studies [8 -11].However, no consensus has been reached regarding the choice of treatment for lung cancer with IPF, and life-threatening acute exacerbation of interstitial pneumonia may occur following radiotherapy, chemotherapy, and surgery [12].Conventional therapeutic strategies face challenges, and alternative treatments are urgently needed.
Image-guided minimally invasive therapies for primary lung cancer are emerging as a promising therapeutic approach, providing effective local control for tumors that are either unresectable or unsuitable for chemotherapy or radiotherapy due to poor cardiopulmonary function or previous surgical intervention [13].Computed tomography (CT)guided percutaneous core-needle biopsy (CNB) is performed to obtain tissue samples for pathological diagnosis and plays a critical role in accurate diagnosis and treatment planning.Thermal ablation techniques, such as radiofrequency ablation (RFA) and microwave ablation (MWA), have been shown to be safe and effective alternatives for patients with early-stage NSCLC [13][14][15][16].In addition, synchronous percutaneous CNB and ablation have higher safety than asynchronous surgery [14].To the best of our knowledge, only a few studies have reported CT-guided percutaneous CNB and RFA or MWA for NSCLC in patients with IPF, showing good tolerability without adverse effects on pulmonary function [17,18].MWA has theoretical advantages over RFA, including better tissue penetration, higher temperatures with less heat-sink effect, shorter procedure duration, and larger ablation zones [19][20][21].
Despite these advantages of MWA, its technical safety, efficacy and complications for the treatment of early-stage NSCLC in patients with IPF are not well understood.Therefore, the aim of this study was to retrospectively evaluate the safety and feasibility of CT-guided synchronous percutaneous CNB and MWA for stage I NSCLC in patients with IPF.

Patients
This single-center, retrospective study included all stage I NSCLC in patients with IPF who underwent CT-guided synchronous percutaneous CNB and MWA at this institution.Approval for this study was obtained from the Beijing Hospital Ethical Inspection Committee.The study protocol was conducted in accordance with the Declaration of Helsinki.The requirement for written informed consent was waived due to the retrospective nature of this study.
The indication was evaluated by a multidisciplinary team consisting of respiratory physicians, thoracic surgeons, oncologists, radiation, and interventional radiologists.The inclusion criteria were as follows: (a) clinical stage IA or IB (based on the 8 th TNM staging system) NSCLC; (b) clinically diagnosed IPF based on imaging findings (including extensive honeycombing, reticular opacities, and ground-glass opacities under the pleura of the basal or peripheral lung); (c) no history of other malignant tumors; (d) unfit for surgery or with operable disease who refuse surgery; (e) not receiving chemotherapy or radiotherapy prior to ablation therapy; (f) Eastern Cooperative Oncology Group performance status (ECOG) of 0-2.Patients with abnormal coagulation tests or uncontrolled infections were excluded.

Instrumentation and procedure
All procedures followed Society of Interventional Radiology guidelines [22] and were performed under CT guidance (GE Discovery 16 Slice CT, GE Healthcare) by the same interventional radiologist with 20 years of experience.The CNB system included a 15-gauge coaxial introducer needle (Co-Axial Introducer Needle; Argon Medical Devices, Athens, Texas) and a 16-gauge full-core biopsy needle (BioPince; Argon Medical Devices).An MTC-3C MWA system (Vision Medical Devices R&D Center, Nanjing, China) was used, with a microwave emission frequency of 2,450 ± 50 MHz and an adjustable continuous wave output power ranging from 0 to 100 W. The microwave antenna had an effective length of 100-180 mm and an outside diameter of 15-18 G, with a 5 mm active tip, and with a water circulation cooling system to reduce the surface temperature.Continuous electrocardiographic monitoring was performed every 5 min throughout the procedure, including heart rate, blood pressure, and pulse oximetry.
Pre-procedural CT was performed to inform the treatment plan and to clarify the appropriate position, puncture site location, optimal puncture trajectory, and the number of MWA antennas (Figures 1 and 2).First, local anesthesia was applied to the selected puncture sites with 5-10 ml of 1% lidocaine.A 15 G coaxial introducer needle was advanced to the proximal edge of the lesion along a designed trajectory, avoiding vessels, bronchi, emphysema, and fissures.A CT scan was performed to confirm the position of the needle tip.Secondly, the stylet was replaced by a 16 G full-core biopsy needle through the cannula, and at least three core specimens were obtained.If the specimen quantity was sufficient for diagnosis, it was submitted in 10% formalin for pathological examination.After removal of the biopsy needle, an 18 G MWA antenna was advanced through the cannula into the lesion.The tip of the microwave antenna extended 0.5-1.0cm beyond the distal edge of the lesion.The MWA power was set at 30-40 W and the duration was 5-15 min.During the ablation, CT scans were repeated to evaluate the distribution of the ablation zone.The procedure was terminated when the ablation zone contained a 5-10 mm rim of ground-glass opacification beyond the lesion boundary.Needle tract embolization was then performed using prepared gelatin sponge particle embolic agent (1400-2000 lm, Alicon, Hangzhou, China), which was gently injected into the needle tract through the coaxial needle.Finally, post-procedure CT images were acquired to evaluate the ablation zone and procedurerelated complications immediately and at 24 h post procedure.In our institution, if there were no complications or adverse events requiring further treatment, patients were usually discharged 48 h after the procedure.

Follow-up and assessments
All patients underwent non-enhanced chest CT 24 h after ablation procedure to detect early-onset asymptomatic complications, including pneumothorax and pleural effusion.Chest tube placement was performed in patients with moderate to severe pneumothorax or pleural effusion.Contrastenhanced chest CT was performed at one, three, and six months and then every six months thereafter based on consensus guidelines in image-guided tumor ablation [23][24][25].Technical success was defined as complete coverage of the lesion by the ablation zone, with an adequate margin on the unenhanced CT scan performed immediately after MWA, and obtaining a biopsy specimen in accordance with the preoperative protocol.Local tumor progression (LTP) was identified by enlargement of ablation zone in comparison with the baseline CT (1 month after MWA) during imaging follow-up, provided that the primary technique efficacy was achieved.Overall survival (OS) was defined as the time between initial MWA and the patient's death of any cause or the last followup.The patients were followed up until June 30, 2023.
Treatment-related complications were assessed according to the Society of Interventional Radiology criteria and classified as major complications, minor complications, and side effects [24,26].Major complications were defined as clinical symptoms experienced during or after ablation that may be life-threatening, result in significant damage and dysfunction, and require hospitalization or prolonged hospitalization.Minor complications were defined as self-limiting complications without sequelae requiring only a short hospital stay for observation or treatment.Side effects included pain, fever, post-ablation syndrome, and asymptomatic minor bleeding or effusion accumulation on CT.

Statistical analysis
All data were analyzed using SPSS for Windows Version 23.0 (IBM, USA).All categorical variables were compared using the v 2 test, and continuous variables were described as the mean/median ± SD.The OS for stage I NSCLC in patient with IPF treated with synchronous percutaneous CNB and MWA was estimated using Kaplan-Meier method.A p-value <0.05 was considered to be statistically significant.

Patient characteristics
The detailed demographic characteristics of stage I NSCLC patients with IPF were shown in Table 1.The patients included fifteen males (78.9%) and four females (21.1%), the mean age 71.42 ± 8.95 years.There were six (31.58%) adenocarcinomas, twelve (63.16%) squamous carcinoma and one (5.26%)large cell carcinoma.And as for clinical stage, seventeen (89.47%) patients were stage as IA, while two (10.53%)patients were in IB.A total of nineteen tumors were treated with MWA in nineteen sessions.

Efficacy and follow-up
All procedures were completed, and the technical success rates were 100%.The duration of MWA ranged from 5 to 15 min, with a mean of 8.6 ± 3.4 min.One month after the procedure, contrast-enhanced chest CT showed complete ablation of NSCLC lesions.With a median follow-up time of 20.36 months, the patient median OS was 25 months (95% CI: 21.79, 28.20).The six-, twelve-and eighteen-month OS rates were 94.73%, 89.47% and 57.89%, respectively.The six-, twelve-and eighteen-month LTP rates were 0%, 10.52% and 31.57%,respectively.The Kaplan-Meier survival curve for nineteen stage I patients with IPF that received MWA treatment are presented in Figure 3.

Discussion
MWA is minimally invasive compared to surgery and is therefore theoretically preferable to protect normal pulmonary function.It is an alternative treatment for stage I NSCLC in patients who are medically inoperable due to high-risk conditions or who are unwilling to undergo surgery.Previous studies have demonstrated that thermal ablation appears to be a safe and effective option for patients with high-risk conditions, such as patients with a single lung after prior pneumonectomy or coexisting severe emphysema [27][28][29].Okuma et al. [17] reported that a patient with stage I NSCLC complicated by IPF was treated with CT-guided RFA, developed pneumothorax and empyema requiring video-assisted thoracoscopic debridement and continuous drainage, and recovered seven months after RFA.No local recurrence or metastasis of the RFA-treated tumor was observed.The good tolerability of percutaneous image-guided pulmonary thermal ablation provides a good treatment option for patients with IPF.In our study, nineteen stage I NSCLC patients with IPF were treated with MWA, and the technical success rate was 100%.The six-month OS and LTP rates were 94.73% and 0%, twelvemonth OS and LTP rates were 89.47% and 10.52%, eighteenmonth OS and LTP rates were 57.89% and 31.57%.There were no peri-procedural deaths during the nineteen sessions of MWA.Together, these results suggest that MWA may be relatively safe and effective and does not worsen respiratory insufficiency.
Lung biopsy is an essential procedure, and the definitive pathological diagnosis can help to better determine the  therapeutic regimen.However, NSCLC lesions in patients with IPF are generally located in the periphery of the lung, where fibrotic lesions are predominant, and it is difficult to obtain tissue samples by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) or electromagnetic navigation bronchoscopy (ENB).Therefore, CT-guided percutaneous CNB may be best suited for sampling in patients with IPF.Shin et al. [30] reviewed the data of 80 patients with IPF who underwent CT-guided percutaneous transthoracic needle lung biopsy; the accuracy, sensitivity, and specificity for the diagnosis of malignancy were 89%, 90%, and 84%, respectively.In our study, there were six (31.58%) adenocarcinomas, twelve (63.16%) squamous cell carcinomas, and one (5.26%)large cell carcinoma, and the diagnostic accuracy of percutaneous CNB was 100%.The results indicated that CT-guided lung biopsy had a relatively reasonable accuracy in diagnosing malignancy in patients with IPF.
The safety of CT-guided synchronous CNB and MWA needs to be taken into account.Pneumothorax is the most frequent complication in imaging-guided percutaneous lung biopsy and MWA and is usually self-limited.Importantly, reports have suggested that patients with IPF are at a higher risk for the development of pneumothorax, and the overall and major complication rates may be high, which is associated with the biopsy needle passing through honeycomb lesions [30].In present study, the NSCLC lesions were adjacent to the pleura (distance from pleura: < 10 mm) in 68.4% of the patients.In addition, CT imaging showed honeycomb, lattice, and ground-glass changes in the surrounding lung tissue.The incidence of pneumothorax requiring drainage in this study was 15.79%, which was at an intermediate level compared with reports in the previous literature (8.5-32%) [31][32][33][34].This was thought to be due to the following reasons: (i) The coaxial technique reduces the number of pleural punctures.(ii) Needle tract embolization was performed using a gelatin sponge particle embolic agent, which was gently injected into the needle tract through the coaxial needle.Peng et al. [34] confirmed that gelatin sponge particles could reduce the incidence of pneumothorax by blocking the puncture needle tract.(iii) The MWA antenna was a monopolar needle, which is superior to the multipolar RFA electrode (3-cm array diameter) reported by Okuma et al. [17,35], and can reduce the thermal damage to the surrounding lung tissue.
In this study, the most common side effect was intraoperative or postoperative local pain, with an incidence rate of 52.63%, especially for the ablation of lesions near the pleura (<10 mm), which was thought to be caused by thermal injury to the visceral pleura.In addition, fibrotic changes in the peripheral lung tissue increased thermal conduction and diffusivity compared to normal lung tissue.In our experience, long-duration, low-power (20-30 W) intermittent ablation could be used in patients with intraoperative pain, and avoid thermal injury.1% lidocaine may also be injected into the intercostal and subpleural areas adjacent to the lesion, or additional intravenous analgesics may be given.Patients with postoperative pain can be well managed with non-steroidal analgesics.These side effects and complications mentioned above could be well controlled with observation or appropriate treatments.There was no mortality during the procedure or within 30 days following MWA.This study demonstrated that synchronous percutaneous CNB and MWA is feasible and safe for the treatment of stage I NSCLC in patients with IPF.
This study had several limitations.First, this was a retrospective nature of study with a small sample size.In addition, this single-arm study lacked a control group.Moreover, the follow-up period was still limited, definitive conclusions could not therefore be drawn regarding the long-term outcomes.

Conclusions
According to the results of the current study, we believe that CT-guided synchronous percutaneous CNB and MWA is a safe procedure and our initial experience is promising; however, its role in the treatment of stage I NSCLC in patients with IPF has not yet been determined.Further prospective studies with large sample sizes and long-term follow-up are needed to provide more convincing evidence.

Figure 1 .
Figure 1.Axial CT images of a 64-year-old man with stage IA NSCLC (adenocarcinoma) with IPF who underwent CT-guided synchronous percutaneous CNB and MWA.(a) CT prior to MWA treatment shows a 1.9 � 1.2 cm lesion in the right lower lobe (arrow); (b), (c) CT findings during MWA treatment, a 15 G coaxial introducer needle (arrow) was advanced to the proximal edge of the lesion, and the antenna was positioned centrally through the cannula into the lesion (arrow); (d) CT image immediately post-procedure showed ground-glass opacity around the tumor (arrow); (e) CT image 24 h post-procedure showed the expected thermal damage around the target lesion, without pneumothorax.(f) CT image 6 months after MWA treatment showed a reduced ablation area (arrow), cavitation changes in the primary focus, and surrounding fibrotic scarring with signs of inflammation.CT: computed tomography; NSCLC: non-small cell lung cancer; IPF: idiopathic pulmonary fibrosis; CNB: core-needle biopsy; MWA: microwave ablation.

Figure 2 .
Figure 2. Axial CT images of a 76-year-old man with stage IA NSCLC (squamous carcinoma) with IPF who underwent CT-guided synchronous percutaneous CNB and MWA.(a) CT prior to MWA treatment showed a 1.4 � 0.9 cm subpleural lesion in the left upper lobe (arrow); (b) CT findings during MWA treatment, the antenna punctured the Central position of the lesion through honeycomb lesions (arrow); (c) CT image 24 h post-procedure showed ground-glass opacity around the tumor (arrow); (d) the 12-month CT image after MWA treatment revealed gradual shrinkage of the ablated lesion, and it became a fiber scar (arrow).CT: computed tomography; NSCLC: non-small cell lung cancer; CNB: core-needle biopsy; MWA: microwave ablation; IPF: idiopathic pulmonary fibrosis.

Figure 3 .
Figure 3. Kaplan-Meier survival curve for nineteen stage I non-small cell lung cancer (NSCLC) patients with idiopathic pulmonary fibrosis (IPF) that received microwave ablation (MWA) treatment.

Table 2 .
Grade of complications during and following MWA.