Radiomics complements clinical, radiological, and technical features to assess local control of colorectal cancer lung metastases treated with radiofrequency ablation.

OBJECTIVES: Radiofrequency ablation (RFA) of lung metastases of colorectal origin can improve patient survival and quality of life. Our aim was to identify pre- and per-RFA features predicting local control of lung metastases following RFA. METHODS: This case-control single-center retrospective study included 119 lung metastases treated with RFA in 48 patients (median age: 60 years). Clinical, technical, and radiological data before and on early CT scan (at 48 h) were retrieved. After CT scan preprocessing, 64 radiomics features were extracted from pre-RFA and early control CT scans. Log-rank tests were used to detect categorical variables correlating with post-RFA local tumor progression-free survival (LTPFS). Radiomics prognostic scores (RPS) were developed on reproducible radiomics features using Monte-Carlo cross-validated LASSO Cox regressions. RESULTS: Twenty-six of 119 (21.8%) nodules demonstrated local progression (median delay: 11.2 months). In univariate analysis, four non-radiomics variables correlated with post-RFA-LTPFS: nodule size (> 15 mm, p < 0.001), chosen electrode (with difference between covered array and nodule diameter < 20 mm or non-expandable electrode, p = 0.03), per-RFA intra-alveolar hemorrhage (IAH, p = 0.002), and nodule location into the ablation zone (not seen or in contact with borders, p = 0.005). The highest prognostic performance was reached with the multivariate model including a RPS built on 4 radiomics features from pre-RFA and early revaluation CT scans (cross-validated concordance index= 0.74) in which this RPS remained an independent predictor (cross-validated HR = 3.49, 95% confidence interval = [1.76 - 6.96]). CONCLUSIONS: Technical, radiological, and radiomics features of the lung metastases before RFA and of the ablation zone at 48 h can help discriminate nodules at risk of local progression that could benefit from complementary local procedure. KEY POINTS: • The highest prognostic performance to predict post-RFA LTPFS was reached with a parsimonious model including a radiomics score built with 4 radiomics features. • Nodule size, difference between electrode diameter, use of non-expandable electrode, per-RFA hemorrhage, and a tumor not seen or in contact with the ablation zone borders at 48-h CT were correlated with post-RFA LTPFS.

Renal cell carcinoma lung metastases treated by radiofrequency ablation integrated with systemic treatments: over 10 years of experience.

BACKGROUND: To determine safety and efficacy of radiofrequency ablation (RFA) for local treatment of lung metastases of renal cell carcinoma (RCC), sequenced or combined with systemic treatments. METHODS: Retrospectively, we studied 53 patients treated by RFA for a maximum of six lung metastases of RCC. The endpoints were local efficacy, overall (OS), disease-free (DFS), pulmonary progression-free (PPFS) and systemic treatment-free (STFS) survivals, complications graded by the CTCAE classification and factors associated with survivals. Potential factors analysed were: clinical and pathological data, tumoral staging of TNM classification, primary tumor histology, Fuhrman's grade, age, number and size of lung metastases and extra-pulmonary metastases pre-RFA. RESULTS: One hundred metastases were treated by RFA. Median follow-up time was 61 months (interquartile range 90-34). Five-year OS was 62% (95% confidence interval (CI): 44-75). Median DFS was 9.9 months (95% CI: 6-16). PPFS at 1 and 3 years was 58.9% (95%CI: 44.1-70.9) and 35.2% (95%CI: 21.6-49.1), respectively. We observed 3% major complications (grade 3 and 4 of CTCAE classification). Local efficacy was 91%. Median STFS was 28.3 months. Thirteen patients (25%) with lung recurrence could be treated by another RFA. T3/T4 tumors had significantly worse OS, PPFS and STFS. Having two or more lung metastases increased the risk of pulmonary progression more than threefold. CONCLUSION: Integrated to systemic treatment strategy, RFA is safe and effective for the treatment strategy of lung metastasis from RCC with good OS and long systemic treatment-free survival. RFA offers the possibility of repeat procedures, with low morbidity.

Primary tumors of the lung: should we consider thermal ablation as a valid therapeutic option?

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer death; percutaneous thermal ablation (TA) has proven feasibility, good local control and good tolerance in stage I tumors for patients with medical comorbidities and who are ineligible for surgery. In this context, stereotactic body radiotherapy (SBRT) has demonstrated high efficacy in treating T1 NSCLC and will need to be compared with percutaneous ablation. TA is also indicated in oligoprogressive disease; and can be proposed as a salvage treatment option for tumor recurrence after radiotherapy. Besides more advanced NSCLC could be also an indication of TA in combination with systemic treatments. A large majority of diagnosed NSCLC do not exhibit specific targetable genetic aberration. Those tumors present poorer prognosis and have been treated with standard chemotherapy regimen until the recent development of immune checkpoint inhibitors (ICIs) based immunotherapy. Combining TA with immunotherapy is promising and still needs to be explored.

Radiofrequency ablation of lung metastases of colorectal cancer: could early radiomics analysis of the ablation zone help detect local tumor progression?

OBJECTIVES: To determine whether radiomics data can predict local tumor progression (LTP) following radiofrequency ablation (RFA) of colorectal cancer (CRC) lung metastases on the first revaluation chest CT. METHODS: This case-control single-center retrospective study included 95 distinct lung metastases treated by RFA (in 39 patients, median age: 63.1 years) with a contrast-enhanced CT-scan performed 3 months after RFA. Forty-eight radiomics features (RFs) were extracted from the 3D-segmentation of the ablation zone. Several supervised machine-learning algorithms were trained in 10-fold cross-validation on reproducible RFs to predict LTP, with/without denoising CT-scans. An unsupervised classification based on reproducible RFs was built with k-means algorithm. RESULTS: There were 20/95 (26.7%) relapses within a median delay of 10 months. The best model was a stepwise logistic regression on raw CT-scans. Its cross-validated performances were: AUROC = 0.72 (0.58-0.86), area under the Precision-Recall curve (AUPRC) = 0.44. Cross-validated balanced-accuracy, sensitivity and specificity were 0.59, 0.25 and 0.93, respectively, using p = 0.5 to dichotomize the model predicted probabilities (vs 0.71, 0.70 and 0.72, respectively using p = 0.188 according to Youden index). The unsupervised approach identified two clusters, which were not associated with LTP (p = 0.8211) but with the occurrence of per-RFA intra-alveolar hemorrhage, post-RFA cavitations and fistulizations (p = 0.0150). CONCLUSION: Predictive models using RFs from the post-RFA ablation zone on the first revaluation CT-scan of CRC lung metastases seemed moderately informative regarding the occurrence of LTP. ADVANCES IN KNOWLEDGE: Radiomics approach on interventional radiology data is feasible. However, patterns of heterogeneity detected with RFs on early re-evaluation CT-scans seem biased by different healing processes following benign RFA complications.

FFCD 1709-SIRTCI phase II trial: Selective internal radiation therapy plus Xelox, Bevacizumab and Atezolizumab in liver-dominant metastatic colorectal cancer.

Immune checkpoint inhibitors (ICI) have high efficacy in metastatic colorectal cancer (mCRC) with microsatellite instability (MSI) but not in microsatellite stable (MSS) tumour due to the low tumour mutational burden. Selective internal radiation therapy (SIRT) could enhance neoantigen production thus triggering systemic anti-tumoral immune response (abscopal effect). In addition, Oxalipatin can induce immunogenic cell death and Bevacizumab can decrease the exhaustion of tumour infiltrating lymphocyte. In combination, these treatments could act synergistically to sensitize MSS mCRCs to ICI SIRTCI is a prospective, multicentre, open-label, phase II, non-comparative single-arm study evaluating the efficacy and safety of SIRT plus Xelox, Bevacizumab and Atezolizumab (anti-programmed death-ligand 1) in patients with liver-dominant MSS mCRC. The primary objective is progression-free survival at 9 months. The main inclusion criteria are patients with MSS mCRC with liver-dominant disease, initially unresectable disease and with no prior oncologic treatment for metastatic disease. The trial started in November 2020 and has included 10 out of the 52 planned patients.

Single-Center Experience of Focal Thermo-Ablative Therapy After Pelvic Radiotherapy for In-Field Prostate Cancer Oligo-Recurrence.

PURPOSE: In-field prostate cancer (PCa) oligo-recurrence after pelvic radiotherapy is a challenging situation for which metastasis-directed treatments may be beneficial, but options for focal therapies are scarce. METHODS: We retrospectively reviewed data for patients with three or less in-field oligo-recurrent nodal, bone and/or locally recurrent (prostate, seminal vesicles, or prostatic bed) PCa lesions after radiation therapy, identified with molecular imaging (PET and/or MRI) and treated by focal ablative therapy (cryotherapy or radiofrequency) at the Institut Bergonié between 2012 and 2020. Chosen endpoints were the post-procedure PSA response (partially defined as a >50% reduction, complete as a PSA <0.05 ng/ml), progression-free survival (PFS) defined as either a biochemical relapse (defined as a rise >25% of the Nadir and above 2 ng/ml), radiological relapse (on any imaging technique), decision of treatment modification (hormonotherapy initiation or line change) or death, and tolerance. RESULTS: Forty-three patients were included. Diagnostic imaging was mostly 18F-Choline positron emission tomography/computerized tomography (PET/CT) (75.0%), prostate specific membrane antigen (PSMA) PET/CT (9.1%) or a combination of pelvic magnetic resonance imaging (MRI), CT, and 99 mTc-bone scintigraphy (11.4%). PSA response was observed in 41.9% patients (partial in 30.3%, complete in 11.6%). In the hormone-sensitive exclusive focal ablation group (n = 31), partial and complete PSA responses were 32.3 and 12.9% respectively. Early local control (absence of visible residual active target) on the post-procedure imaging was achieved with 87.5% success. After a median follow-up of 30 months (IQR 13.3-56.8), the median PFS was 9 months overall (95% CI, 6-17), and 17 months (95% CI, 11-NA) for PSA responders. Complications occurred in 11.4% patients, with only one grade IIIb Dindo-Clavien event (uretral stenosis requiring endoscopic uretrotomy). CONCLUSION: In PCa patients showing in-field oligo-recurrence after pelvic radiotherapy, focal ablative treatment is a feasible option, possibly delaying a systemic treatment initiation or modification. These invasive strategies should preferably be performed in expert centers and discussed along other available focal strategies in multi-disciplinary meetings.

From palliative to curative intent: PET/CT findings in the light of breast cancer intrinsic subgroup.

PURPOSE: Among breast cancer subgroups, Luminal A is the subgroup with the best prognosis. We report the case of a young woman presenting with a localized luminal A breast cancer with a suspicious liver lesion on initial positron emission tomography (PET)/computed tomography (CT) scan staging. CASE DESCRIPTION: A 31-year-old woman presented with localized breast cancer accessible to curative treatment. However, PET/CT staging revealed an increase of focal activity in the liver, suspicious of a secondary malignant localization, changing the care towards palliative intent. Discrepancy between breast cancer luminal A subtype and the liver lesion led to further investigations (contrast ultrasound, magnetic resonance imaging, and biopsy), excluding a malignant process, and were in favor of toxic hepatitis, probably secondary to herbal tea consumption. CONCLUSIONS: Questioning PET/CT findings in light of the cancer subtype enabled us to rectify the diagnosis and allow this patient to be treated with curative intent.

Assessment of risk factors for occurrence or worsening of acetabular fracture following percutaneous cementoplasty of acetabulum malignancies.

PURPOSE: To evaluate the clinical, radiological and periprocedural features associated with the occurrence or worsening of acetabular fracture (OWAF) following percutaneous cementoplasty of the acetabulum (PCA) in cancer patients. METHOD: All patients who underwent PCA in our comprehensive cancer center for an acetabular metastasis between January 2008 and December 2015 were included. Clinical features, characteristics of the metastasis on computed tomography (CT-scan) (location [roof, quadrilateral surface, anterior and posterior columns], number of locations, matrix, extra/intra-articular fractures, extra-osseous or subchondral extensions) and of the procedure (extra- or intra-articular cement leakage (IACL), percentage of filling of each location, complications) were reported as well as prior, concomitant or post-PCA treatments. The endpoint was OWAF on CT-scan during post-PCA follow-up. Log-rank tests and Cox models were used to identify prognostic factors. RESULTS: 140 PCA were identified in 129 patients (11 bilateral procedures, median age: 66.6). Eighteen (18/140, 12.9%) had an initial articular fracture. IACL was seen in 12/140 (8.6%) PCA. The only feature associated with IACL was a pre-existing articular fracture (p = 0.009). Of the 111 patients with imaging follow-ups, 18 (16.2%) showed OWAF. In multivariate analysis, the presence of cement filling (even partial) of all acetabular metastatic locations was the only feature predictive of OWAF-free survival (hazard ratio = 3.8, p = 0.031). CONCLUSIONS: Injecting cement in all areas affected by acetabular metastases could prevent OWAF. Because survival following PCA is not negligible, completing an insufficient first PCA could help preserve patients' quality of life.

Image-Guided Bone Consolidation in Oncology.

Occurrence of bone metastases is a common event in oncology. Bone metastases are associated with pain, functional impairment, and fractures, particularly when weight-bearing bones are involved. Management of bone metastases has been improved by the development of various interventional radiology consolidation techniques. Cementoplasty is based on injection of acrylic cement into a weakened bone to reinforce it and to control pain. This minimally invasive technique has proven its efficacy for flat bone submitted to compression forces. However, resistance to torsion forces is limited and, thus, treatment of long bones should be considered with caution. In recent years, variant techniques of percutaneous bone consolidation have emerged, including expansion devices for vertebral augmentation and percutaneous screw fixation for pelvic bone and proximal femur tumors. Research projects are ongoing to develop drug-loaded cements to use them as therapeutic vectors. However, release of drugs is still poorly controlled and conventional polymethylmethacrylate cement remains the gold standard in oncology. Image-guided consolidation techniques enhance the array of treatments in bone oncology. Multidisciplinary approach is mandatory to select the best indications.

Pulmonary Thermal Ablation Enables Long Chemotherapy-Free Survival in Metastatic Colorectal Cancer Patients.

BACKGROUND: Chemotherapy (ct) is the preferred treatment option in metastatic colorectal cancer (mCRC). The objective of the study was to determine the overall survival (OS), disease-free survival (DFS) and ct-free survival (CFS) of pulmonary thermal ablation (TA) and its place in the treatment of mCRC. PATIENTS AND METHODS: All consecutive patients treated (over 11 years) with percutaneous TA for lung metastasis of colorectal origin were reviewed. All sequences of treatments were considered. We determined the OS, DFS and CFS of pulmonary TA. RESULTS: Two hundred and nine patients underwent 323 TA procedures for 630 lung metastases. Majority of the metastases (71.5%) were unilateral with a median diameter of 10 mm (2-46). A single metastasis was treated in 95 patients (45.5%), and 2-8 in 114 patients (54.5%). One hundred and thirty-two patients (63.2%) had only a single procedure, 77 patients (36.8%) had 2-5 procedures. Following the first TA (n = 209), 125 patients (59.8%) resumed ct. Sixty-four out of the 126 patients presenting lung progression were treated again with TA. The median CFS was 12.2 months (95% CI: 10.3-17.7). Patients with no extra-pulmonary metastases showed a statistically better CFS than those who had extra-pulmonary metastases with a median of 20.9 and 9.2 months, respectively (p < 0.001). Median follow-up and OS were 50 and 67.6 months, respectively. CONCLUSION: This study demonstrates, for the first time, that TA enables a CFS of 12.2 months that extended to 20.9 months in patients who presented with lung-only metastases. TA is a viable option for a pause in the therapy of mCRCs.

[Percutaneous lung thermo-ablation]. / Thermo-ablation pulmonaire percutanée.

Percutaneous lung thermo-ablation has steadily been developed over the past 15years. Main indications are early stage non-small cell lung carcinoma (NSCLC) for non-surgical patients and slow evolving localized metastatic disease, either spontaneous or following a general treatment. Radiofrequency, being the most evaluated technique, offers a local control rate of about 80-90% for tumors <3 cm in diameter. With excellent tolerance and very few complications, radiofrequency may be proposed for patients with a chronic disease. Other ablation techniques under investigation such as microwaves and cryotherapy could allow overcoming radiofrequency limits. Furthermore, stereotactic radiotherapy proposed for the same indications is efficient. Comparative studies are warranted to differentiate these techniques in terms of efficacy, tolerance and cost-effectiveness.

[Image-guided bone consolidation in oncology: Cementoplasty and percutaneous screw fixation]. / Techniques de consolidation osseuse guidée par imagerie en oncologie : cimentoplastie et vissage.

Bone metastases are a common finding in oncology. They often induce pain but also fractures which impair quality of life, especially when involving weight-bearing bones. Percutaneous image-guided consolidation techniques play a major role for the management of bone metastases. Cementoplasty aims to stabilize bone and control pain by injecting acrylic cement into a weakened bone. This minimally invasive technique has proven its efficacy for bones submitted to compression forces: vertebra, acetabular roof, and condyles. However, long bone diaphysis should be treated with caution due to lower resistance of the cement subject to torsional forces. The recent improvements of navigation systems allow percutaneous image-guided screw fixation without requiring open surgery. This fast-track procedure avoids postponing introduction of systemic therapies. If needed, cementoplasty can be combined with screw insertion to ensure better anchoring in major osteolysis. Interventional radiology bone consolidation techniques increase the therapeutic field in oncology. A multidisciplinary approach remains mandatory to select the best indications.

Percutaneous Image-Guided Screw Fixation of Bone Lesions in Cancer Patients: Double-Centre Analysis of Outcomes including Local Evolution of the Treated Focus.

AIM: To review outcomes and local evolution of treated lesions following percutaneous image-guided screw fixation (PIGSF) of pathological/insufficiency fractures (PF/InF) and impeding fractures (ImF) in cancer patients at two tertiary centres. MATERIALS AND METHODS: Thirty-two consecutive patients (mean age 67.5 years; range 33-86 years) with a range of tumours and prognoses underwent PIGSF for non/minimally displaced PF/InF and ImF. Screws were placed under CT/fluoroscopy or cone-beam CT guidance, with or without cementoplasty. Clinical outcomes were assessed using a simple 4-point scale (1 = worse; 2 = stable; 3 = improved; 4 = significantly improved). Local evolution was reviewed on most recent follow-up imaging. Technical success, complications, and overall survival were evaluated. RESULTS: Thirty-six lesions were treated with 74 screws mainly in the pelvis and femoral neck (58.2 %); including 47.2 % PF, 13.9 % InF, and 38.9 % ImF. Cementoplasty was performed in 63.9 % of the cases. Technical success was 91.6 %. Hospital stay was ≤3 days; 87.1 % of lesions were improved at 1-month follow-up; three major complications (early screw-impingement radiculopathy; accelerated coxarthrosis; late coxofemoral septic arthritis) and one minor complication were observed. Unfavourable local evolution at imaging occurred in 3/24 lesions (12.5 %) at mean 8.7-month follow-up, including poor consolidation (one case) and screw loosening (two cases, at least 1 symptomatic). There were no cases of secondary fractures. CONCLUSIONS: PIGSF is feasible for a wide range of oncologic patients, offering good short-term efficacy, acceptable complication rates, and rapid recovery. Unfavourable local evolution at imaging may be relatively frequent, and requires close clinico-radiological surveillance.

Cone-Beam Computed Tomography (CBCT) Versus CT in Lung Ablation Procedure: Which is Faster?

AIM: To compare cone-beam CT (CBCT) versus computed tomography (CT) guidance in terms of time needed to target and place the radiofrequency ablation (RFA) electrode on lung tumours. MATERIALS AND METHODS: Patients at our institution who received CBCT- or CT-guided RFA for primary or metastatic lung tumours were retrospectively included. Time required to target and place the RFA electrode within the lesion was registered and compared across the two groups. Lesions were stratified into three groups according to their size (<10, 10-20, >20 mm). Occurrences of electrode repositioning, repositioning time, RFA complications, and local recurrence after RFA were also reported. RESULTS: Forty tumours (22 under CT, 18 under CBCT guidance) were treated in 27 patients (19 male, 8 female, median age 67.25 ± 9.13 years). Thirty RFA sessions (16 under CBCT and 14 under CT guidance) were performed. Multivariable linear regression analysis showed that CBCT was faster than CT to target and place the electrode within the tumour independently from its size (ß = -9.45, t = -3.09, p = 0.004). Electrode repositioning was required in 10/22 (45.4 %) tumours under CT guidance and 5/18 (27.8 %) tumours under CBCT guidance. Pneumothoraces occurred in 6/14 (42.8 %) sessions under CT guidance and in 6/16 (37.5 %) sessions under CBCT guidance. Two recurrences were noted for tumours receiving CBCT-guided RFA (2/17, 11.7 %) and three after CT-guided RFA (3/19, 15.8 %). CONCLUSION: CBCT with live 3D needle guidance is a useful technique for percutaneous lung ablation. Despite lesion size, CBCT allows faster lung RFA than CT.

Retrospective review of thoracic neural damage during lung ablation - what the interventional radiologist needs to know about neural thoracic anatomy.

BACKGROUND AND PURPOSE: Radiofrequency ablation (RFA) is associated with low neural morbidity compared with surgery, which commonly causes debilitating long-term pain. The purpose was to review the thoracic neural anatomy relevant to percutaneous RFA and to retrospectively review symptomatic nerve injury after lung RFA at our institution. MATERIALS AND METHODS: We retrospectively examined all symptomatic nerve injuries occurring after computed tomography (CT)-guided RFA treatment of lung tumors for 462 patients/509 procedures/708 lesions treated at our large tertiary referral centre during 10 years. RESULTS: Eight patients experienced neurological complications after heating during the RFA procedure. These complications occurred in the phrenic (n = 1), brachial (n = 3), left recurrent (n = 1), and intercostal nerves (n = 2) and the stellate ganglion (n = 1). Three were grade 2, four grade 3 and one grade 4 injuries (CTCAE v3). CONCLUSION: Although rare, neurological complications can occur after RFA, and they can occasionally be severe. To prevent these complications, it is important for the interventional radiologist to be aware of the anatomy of nervous structures and to attempt to identify nerves on CT scans during the RFA procedure. Creating a pneumothorax can be useful to avoid nerve damage and related clinical complications.