Yttrium-90 Radiation Segmentectomy in Oligometastatic Secondary Hepatic Malignancies

Clinical and dosimetric considerations for yttrium-90 glass microspheres radioembolization of intrahepatic cholangiocarcinoma, metastatic colorectal carcinoma, and metastatic neuroendocrine carcinoma: recommendations from an international multidisciplinary working group

PURPOSE

The TheraSphere Global Steering Committee reconvened to review clinical data and address knowledge gaps related to treatment and dosimetry in non-HCC indications using Yttrium-90 (90Y) glass microspheres.

METHODS

A PubMed search was performed. References were reviewed and adjudicated by the Delphi method. Recommendations were graded according to the degree of recommendation and strength of consensus. Dosimetry focused on a mean dose approach, i.e., aiming for an average dose over either single or multicompartment volumes of interests. Committee discussion and consensus focused on optimal patient selection, disease presentation, liver function, tumour type, tumour vascularity, and curative/palliative treatment intent for intrahepatic cholangiocarcinoma (iCCA) and colorectal and neuroendocrine carcinoma liver metastases (mCRC, mNET).

RESULTS

For all indications, single compartment average perfused volume absorbed dose ≥ 400 Gy is recommended for radiation segmentectomy and 150 Gy for radiation lobectomy. Single compartment 120 Gy for uni- and bilobar treatment reflects current clinical practice, which results in variable tumour and normal tissue absorbed doses. Therefore, multicompartment dosimetry is recommended for uni- and bilobar treatment, aiming for maximum 75 Gy to normal tissue and 150-200 Gy (mCRC, mNET), ≥ 205 (iCCA) tumour absorbed doses. These dose thresholds are preliminary and should be used with caution accounting for patient specific characteristics.

CONCLUSION

Consensus recommendations are provided to guide clinical and dosimetry approaches for 90Y glass microsphere radioembolization in iCCA, mCRC and mNET.

CLINICAL TRIAL NUMBER

not applicable.

Voxel-Based Dosimetry Predicts Local Tumor Progression Post 90 Y Radiation Segmentectomy of Colorectal Liver Metastases

BACKGROUND

Radiation segmentectomy (RS) is an alternative potential local curative treatment for selected colorectal liver metastases (CLMs) not amenable to ablation or limited resection.

PURPOSE

The aim of this study was to evaluate the dosimetric response of low volume CLMs to RS in heavily pretreated patients who are not candidates for resection or percutaneous ablation.

PATIENTS AND METHODS

This single-center retrospective study evaluated CLMs patients treated with RS (prescribed tumor dose >190 Gy) from 2015 to 2023. RS doses to tumor(s) and margins were calculated from SPECT/CT and PET/CT images. Response and local tumor progression (LTP) were assessed using anatomic (RECIST 1.1) and metabolic (PERCIST) criteria. LTP-free survival (LTPFS) and overall survival were estimated with Kaplan-Meier methodology. Variables were assessed as predictors of LTPFS using the Cox proportional hazards model.

RESULTS

Thirty-six patients underwent 38 RS procedures to treat 57 tumors. Median time from initial diagnosis to detection of liver metastases and RS were 16.4 (interquartile range: 6.5-32.2) and 26.8 (interquartile range: 12.5-40.0) months, respectively. Median overall survival after RS was 14.3 (95% confidence interval [CI]: 10.8-30.7) months. Predictors of LTPFS included tumor number(s), mean tumor dose (MTD), and margin mean absorbed dose (MMAD). Complete radiographic (hazards ratio [HR]: 1.29e-16, 95% CI: 4.06e-17-4.07e-16, P < 0.001) and metabolic response (HR: 0.38, 95% CI: 0.15-0.95, P = 0.038) correlated with prolonged LTPFS. One-year LTPFS rate was 83.3% for tumors receiving MTD ≥400 Gy and a 5-mm surrounding MMAD ≥350 Gy ( P = 0.006). No instances of LTP were observed when tumors received stereotactic irradiation over 300 Gy (at least 95% of the tumor volume received ≥300 Gy). One-year LTPFS rate for tumors receiving MTD ≥400 Gy was 68.6% versus 14.3% for those that did not reach this threshold ( P = 0.013). In multivariate analysis, MTD ≥400 Gy and 5-mm MMAD ≥350 Gy were independent predictors of LTPFS (HR: 0.11; 95% CI: 0.01-0.81; P = 0.03).

CONCLUSIONS

MTD ≥400 Gy, MMAD ≥350 Gy, and stereotactic tumor irradiation ≥300 Gy are associated with prolonged LTPFS after RS for CLMs.

Yttrium-90 Radiation Segmentectomy for Treatment of Neuroendocrine Liver Metastases

PURPOSE

To assess the safety and effectiveness of yttrium-90 (90Y) radiation segmentectomy (RS) for neuroendocrine tumor liver metastases (NELMs).

MATERIALS AND METHODS

This single-institution retrospective study included 18 patients with 23 liver tumors not amenable to resection or ablation, who underwent RS between 2009 and 2021. Tumor grades by Ki-67/mitotic indices were Grade I (n = 9/23, 39%), Grade II (n = 10/23, 45%), and Grade III (n = 4/23, 17%). Eleven patients (61%) were previously treated with somatostatin analogs, 5 (28%) with chemotherapy, and 2 (11%) with peptide receptor radionuclide therapy. Safety was assessed with preprocedural/postprocedural liver chemistries, blood counts, and clinical adverse events (AEs) using National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Tumor response was assessed per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and modified RECIST (mRECIST) criteria. Kaplan-Meier analysis was used to estimate median overall survival (OS), progression-free survival (PFS), and time to progression (TTP) from the date of 90Y.

RESULTS

Median follow-up was 31.9 months. Grade 1 fatigue was observed in 13 of 18 patients (72%), with 1 of 18 patients (6%) experiencing Grade 3 fatigue. Three patients (17%) exhibited Grade 3 lymphopenia. No other Grade 3 or any Grade 4 AE was observed. Tumor objective response was achieved in 83% of patients by RECIST size criteria and 100% by mRECIST enhancement criteria. Median OS was 69.4 months (95% CI, 23.1-99.4), and median PFS was 12.2 months (95% CI, 4.6-28.8). Median overall TTP was 13.0 months (95% CI, 4.6-45.1), with median treated tumor TTP not reached.

CONCLUSIONS

90Y RS demonstrated high rates of antitumor response with a favorable toxicity profile and durable OS in the treatment of NELMs.

Systemic Immunological Changes After Yttrium-90 Radioembolization: A Pilot Prospective Observational Study-Clinical Insights

PURPOSE

To prospectively investigate levels of circulating cytokines, changes in frequencies of various immune cell subsets and expression of proliferation and checkpoint molecules on T cells in the peripheral blood after yttrium-90 radioembolization (TARE) of colorectal cancer liver metastases (CLM).

MATERIALS AND METHODS

We prospectively collected, isolated, and froze peripheral blood mononuclear cells (PBMC) and plasma samples from 15 patients immediately before, immediately after, 3 and 6 weeks post-TARE of CLM. Plasma samples were assessed for various cytokines using a multiplex immunoassay platform. PBMC samples were analyzed in a monocyte/dendritic cell (DC)/B cell flow panel and a T cell activation/exhaustion flow phenotyping panel. We compared the levels at the respective time points using Wilcoxon signed rank test.

RESULTS

IFN-g significantly decreased immediately after (mean 1.62 vs. 3.02 at baseline, p = 0.04) and increased at 6 weeks compared to the immediately post-TARE nadir (mean 9.42 vs. 1.62, p = 0.04). IL-10 decreased at 3 weeks (mean 0.36 vs. 1.75, p = 0.025) post-TARE compared to baseline. Increased CD3+T cells (mean 78.24 vs. 60.8, p = 0.002) and decreased CTLA-4+CD4+T cells (mean 2.58 vs. 4.41, p = 0.033) were observed at 3 weeks compared to baseline. Increased Ki-67+ proliferating CD8+T cells at 3 and 6 weeks (mean 7.28 and 9.06, respectively, vs. 3.93 at baseline, p = 0.02 and 0.03) were recorded.

CONCLUSION

A shift toward a favorable antitumoral cytokinic and immune cells response was observed after TARE. Significant changes were in specialized immune cells subsets playing important roles in the activation of the immune system. These results support trials combining TARE with immunotherapy for patients with CLM.

Modified Radiation Lobectomy Strategy of Radioembolization for Right-Sided Unresectable Primary Liver Tumors

PURPOSE

To assess the safety and effectiveness of using modified radiation lobectomy (mRL) to treat primary hepatic tumors located in the right hepatic lobe (Segments V-VIII) and to determine future liver remnant (FLR) hypertrophy.

MATERIALS AND METHODS

A retrospective review was performed at a single institution to include 19 consecutive patients (7 females, 12 males) who underwent single-session mRL for right-sided primary hepatic tumors: 15 received segmentectomy plus lobectomy (segmental dose of >190 Gy and lobar dose of >80 Gy); 4 were treated with the double-segmental approach (dominant segments of >190 Gy and nondominant segments of >80 Gy). Treated tumors included 13 hepatocellular carcinoma (HCC), 4 cholangiocarcinoma (CCA), and 2 mixed-type HCC-CCA with a median dominant tumor size of 5.3 cm (interquartile range [IQR], 3.7-7.3 cm). FLR of the left hepatic lobe was measured at baseline, T1 (4-8 weeks), T2 (2-4 months), T3 (4-6 months), and T4 (9-12 months).

RESULTS

Objective tumor response and tumor control were achieved in 17 of the 19 (89.5%) and 18 of the 19 (94.7%) patients, respectively. FLR hypertrophy was observed at T1 (median, 47.8%; P = .025), T2 (median, 48.4%; P = .012), T3 (median, 50.4%; P = .015), and T4 (median, 59.1%; P < .001). Patients without cirrhosis demonstrated greater hypertrophy by 6 months (median, 55.8% vs 47.2%; P = .031). One patient developed a Grade 3 adverse event (ascites requiring paracentesis) at 1-month follow-up. Grade ≥2 serum toxicities were associated with worse baseline Child-Pugh Score, serum albumin, and total bilirubin (P < .05). Among 7 patients who underwent neoadjuvant mRL, 2 underwent resection and 1 received liver transplant.

CONCLUSIONS

mRL appears safe and effective for treatment of right-sided primary hepatic tumors with the benefit of promoting FLR hypertrophy.

Local-Regional Therapy for Oligometastatic Colorectal Cancer

ABSTRACT

Colorectal cancer is one of the most common malignancies in the United States as well as a leading cause of cancer-related death. Upward of 30% of patients ultimately develop metastatic disease, most commonly to the liver and lung. Untreated, patients have poor survival. Historically, patients with oligometastatic disease were treated with resection leading to long-term survival; however, there are many patients who are not surgical candidates. Innovations in thermal ablation, hepatic artery infusions, chemoembolization and radioembolization, and stereotactic ablative radiation have led to an expansion of patients eligible for local therapy. This review examines the evidence behind each modality for the most common locations of oligometastatic colorectal cancer.

Histopathologic Changes after Yttrium-90 Radioembolization of Colorectal Liver Metastases: A Pilot Feasibility Study

PURPOSE

To evaluate the histopathologic changes and potential correlations of tumor absorbed dose (TAD) after yttrium-90 transarterial radioembolization (TARE) for colorectal liver metastases (CLMs).

MATERIALS AND METHODS

This prospective pilot study assessed 12 patients with 13 CLMs through positron emission tomography (PET)/computed tomography (CT)-guided biopsies before, immediately after TARE (T0), and 3 weeks after TARE (T3). Subsequent sampling from the same location was enabled by fiducial placement. Biopsy samples were evaluated with hematoxylin and eosin, TUNEL, Ki67, OxPhos, caspase-3 (CC3), and pH2AX antibodies. Proliferation changes (Ki67) and double-strand DNA breaks (DSBs) were evaluated quantitatively. TAD was calculated on post-TARE PET/CT scan of the biopsy needle location at T0 and T3.

RESULTS

Median TAD at 3 weeks after TARE was 162 Gy (interquartile range (IQR), 92-211 Gy). DSBs decreased significantly from T0 (median, 77%; IQR, 75%-100%) to T3 (median, 14%; IQR, 0%-54%; P = .028). A decrease in Ki67 was also documented (median, 73%; IQR, 70%-80% at T0 vs median, 41%; IQR, 0%-66% at T3; P = .046). There was a strong positive correlation between TAD and DSBs at T0 (r[9] = 0.68) and a strong negative correlation at T3 (r[10] = -0.855; P = .042 and P = .002, respectively). There was a strong negative correlation between TAD and Ki67 at both T0 (r[9] = -0.733; P = .025) and T3 (r[10] = -0.681; P = .030). Tumors that exhibited caspase-3 activation (8/13, 62%) at either T0 or T3 time point were more likely to develop progression (7/8 [88%] vs 1/5 [20%]; P = .015).

CONCLUSIONS

Post-TARE biopsy can be used to assess TAD and histopathologic changes. Significant decreases in DSBs and proliferation index were noted after TARE. Post-TARE CC3 activation deserves further exploration.

Yttrium-90 Transarterial Radioembolization of Primary Lung Cancer Metastases to the Liver

PURPOSE

To assess whether yttrium-90 transarterial radioembolization (TARE) is safe and effective in the treatment of primary lung cancer metastases to the liver (LCML).

METHODS AND METHODS

This retrospective study included 57 patients with LCML who were treated with 79 TARE treatments. Histology included non-small cell lung cancer (NSCLC) (n = 27), small cell lung cancer (SCLC) (n = 17), and lung carcinoid (LC) (n = 13). Survival was calculated using Kaplan-Meier method; differences between groups were estimated using log rank test. Cox proportional hazards model was used to determine factors influencing survival. Adverse events were graded using the Society of Interventional Radiology Adverse Events Classification.

RESULTS

Median overall survival (OS) was as follows: NSCLC, 8.3 months (95% confidence interval [CI], 6.3-16.4 months); SCLC, 4.1 months (95% CI, 1.9-6.6 months); and LC, 43.5 months (95% CI, 7.8-61.4 months). For NSCLC, presence of bilobar vs unilobar disease (hazard ratio [HR], 5.24; 95% CI, 1.64-16.79; P = .002); more tumors, 2-5 vs 1 (HR, 4.88; 95% CI, 1.17-20.37; P = .003) and >5 vs 1 (HR, 3.75; 95% CI, 0.95-6.92; P = .05); and lobar vs segmental treatment (HR, 2.56; 95% CI, 0-NA; P = .002) were negative predictors of OS. For SCLC, receipt of >2 lines of chemotherapy vs ≤2 lines (HR, 3.16; 95% CI, 0.95-10.47; P = .05) was a negative predictor of OS. For LC, tumor involvement of >50% was a negative predictor of OS (HR, 3.77 × 1015; 95% CI, 0-NA; P = .002). There were 11 of 79 severe or life-threatening adverse events within 30 days (abdominal pain, altered mental status, nausea/vomiting, acalculous/aseptic cholecystitis, hyponatremia, pancreatitis, renal failure, and death from pneumonia).

CONCLUSIONS

TARE has an acceptable safety profile for the treatment of LCML, with survival benefits best seen in LC tumors.

Interventional radiological therapies in colorectal hepatic metastases

Colorectal malignancy is the third most common cancer and one of the prevalent causes of death globally. Around 20-25% of patients present with metastases at the time of diagnosis, and 50-60% of patients develop metastases in due course of the disease. Liver, followed by lung and lymph nodes, are the most common sites of colorectal cancer metastases. In such patients, the 5-year survival rate is approximately 19.2%. Although surgical resection is the primary mode of managing colorectal cancer metastases, only 10-25% of patients are competent for curative therapy. Hepatic insufficiency may be the aftermath of extensive surgical hepatectomy. Hence formal assessment of future liver remnant volume (FLR) is imperative prior to surgery to prevent hepatic failure. The evolution of minimally invasive interventional radiological techniques has enhanced the treatment algorithm of patients with colorectal cancer metastases. Studies have demonstrated that these techniques may address the limitations of curative resection, such as insufficient FLR, bi-lobar disease, and patients at higher risk for surgery. This review focuses on curative and palliative role through procedures including portal vein embolization, radioembolization, and ablation. Alongside, we deliberate various studies on conventional chemoembolization and chemoembolization with irinotecan-loaded drug-eluting beads. The radioembolization with Yttrium-90 microspheres has evolved as salvage therapy in surgically unresectable and chemo-resistant metastases.