Radioablation of liver malignancies with interstitial high-dose-rate brachytherapy

Comprehensive cohort study: computer tomography-guided high-dose rate brachytherapy as metastasis-directed therapy for liver metastases from colorectal cancer in repeat oligoprogression

PURPOSE

The standard treatment for oligometastatic colorectal cancer includes systemic therapy, with surgery and metastasis-directed therapy as options. The optimal strategy, especially for repeat oligoprogression (rOP), remains unclear. We report outcomes of liver computer tomography-guided high-dose rate brachytherapy (CT-BRT) in this setting.

METHODS

This retrospective cohort study included colorectal cancer patients with liver-only oligoprogression during systemic therapy, meeting criteria of up to 5 liver metastases, CT-BRT eligibility, and ECOG status ≤ 2. Patients were followed for local response, progression-free survival (PFS), overall survival (OS), and toxicity. Response, according to RECIST 1.1, was initiated 6 months post-CT-BRT.

RESULTS

A total of 262 metastases were treated in 127 patients, with 67.7% receiving third-line or later systemic therapies. One to four liver metastases were found in 29.1%, 42.5%, 21.2%, and 7.1% of patients, respectively, with a median volume of 128 cm3. A median of 3 applicators was used, with CT-BRT doses of 15 Gy, 20 Gy, and 25 Gy given to 29.9%, 41.7%, and 28.3% of patients. At 6 months complete response occurred in 3.1%, progressive disease in 23.6%, partial response in 19.7%, and stable disease in 53.5%. Median PFS was 9 months, median OS was 16 months, with 1-year and 2-year OS rates of 65% and 16%, respectively. Liver-only metastases and objective response were associated with longer PFS. The G3 toxicity was 4.0%; no events > G3 were reported.

CONCLUSIONS

This largest study documents favorable outcomes of liver CT-BRT for rOP, establishing this method as a viable option in this indication.

Efficacy and factors related to prognosis of combination chemotherapy with different radiotherapy methods in patients with unresectable hepatocellular carcinoma

Apart from beam radiation (BR), treatment with radioactive implants (RI) was another important modality of cancer therapy. The main purpose was to explore which radiotherapy combined with chemotherapy was more beneficial and identify factor related to prognosis for patients with unresectable hepatocellular carcinoma (HCC). Patients were collected from the surveillance, epidemiology, and end results (SEER) database and were divided into RI group and BR group. Overall survival (OS) and HCC-specific survival were compared between two groups. Propensity score matched (PSM) was used to reduce baseline differences between the two groups. Univariate and multivariate Cox analysis were used to determine the factors affecting the prognosis, and a nomogram model was constructed based on independent risk factors. A total of 1481 HCC patients from 2000 to 2019 were enrolled, including 502 in RI group and 979 in BR group. After PSM, 376 pairs of matched cases were selected. In the matched cohort, there was no significant difference in the median OS (RI vs. BR, 15 vs. 17 months, P = 0.616) and HCC-specific survival (RI vs. BR, 18 vs. 21 months, P = 0.154) between the two groups. Subgroup analysis of different stages also showed no significant difference. Multivariate Cox analysis also did not indicate a significant prognostic difference between the two groups. Based on the independent risk factors of OS such as AFP, grade, TNM staging, and M1, a nomogram model was constructed and verified. When combined with chemotherapy in the treatment of unresectable HCC, RI demonstrated comparable prognostic outcomes to BR, suggesting its potential as an alternative treatment option. In addition, the constructed nomogram model might be able to intuitively and accurately predict the prognosis of unresectable HCC patients receiving chemotherapy combined with radiotherapy.

Management of liver metastases (oligometastatic) by high-dose-rate interstitial brachytherapy: A case series

PURPOSE

To evaluate the feasibility, efficacy, and safety of interstitial brachytherapy in cases of oligo-metastatic liver disease.

MATERIALS AND METHOD

Four cases of liver metastases were managed over a period of 1 year in our center with close follow-up. All patients had progressive disease with histopathologially proven liver metastases and were ineligible for surgery. The procedure involved placement of brachytherapy catheters under computed tomography (CT) guidance post placement of a single 6F angiography sheath. The median size of metastasis was 2.9 cm (range 2.2-3.4 cms) in diameter, and a single fraction of radiation dose (10 to 13 Gy) was delivered. The angiography sheath and brachytherapy catheters were removed under fluoroscopic guidance post completion of the procedure with the help of an interventional radiologist. The fluoro guidance for removal of catheters was to observe any bleed. Response to treatment in terms of control of the metastases along with complications, safety, and efficacy of the procedure was observed.

RESULTS

All patients underwent re-evaluation with WB-PET-CT after 1 and 6 months. In three cases, complete response with no metabolic activity was noted on WB-PET-CT scan, and in one case, there was a partial response with a decrease in the size and metabolic activity of the metastasis. No fatal complications were noted; however, acute complications like grade 1 nausea, grade 1 vomiting, pain, and local hemorrhage were noted within 1 week of the procedure.

CONCLUSION

Liver interstitial brachytherapy is a feasible option in patients with maybe oligo metastatic solid tumors requiring a multi-disciplinary team effort. It is also an option for patients who are unfit for surgical excision. This is the first reported case series in India using high-dose-rate (HDR) brachytherapy techniques with an angiography sheath and flexible brachytherapy catheters.

Mortality and postinterventional complications after ablative treatment of liver malignancies: A cohort study of 4374 patients

PURPOSE

Ablative therapies for primary and secondary liver malignancies are increasingly adopted in current guidelines. Nevertheless, surgical resection remains the gold standard in most curative therapy settings. Extensive studies on mortality and morbidity after ablative treatment of the liver are missing. We investigated complications and mortality after ablative treatment in a large, unselected study cohort.

MATERIALS AND METHODS

Standardized patient and treatment data in 4374 percutaneous and angiographic ablative procedures of the liver from the DRG-based hospital reimbursement system (diagnosis-related groups) of an academic hospital in Germany were retrospectively evaluated. We analyzed descriptive patient data, length of stay (LOS), pre-existing medical conditions, previous gastrointestinal surgeries, severe complications, and occurrence of death.

RESULTS

Treatment of secondary liver malignancies constituted over two-thirds of all procedures (71%, n = 3053). The mean LOS was 4.1 ± 3.5 days. Severe complications were documented in 1.4% and in-house death in 0.2% of cases, significantly more often after treatment with chemoembolization of primary liver malignancies (p = 0.003; p = 0.0001). Previous partial liver resection, partial bowel resection, and chronic renal failure were independent risk factors for the occurrence of severe complications.

CONCLUSION

Severe complications and in-hospital death are rare in the treatment of primary and secondary liver malignancies with percutaneous and angiographic procedures. They are a viable alternative or addition to a surgical approach in treating liver lesions.

Effectiveness and safety of computed tomography-guided high-dose-rate brachytherapy in treating recurrent hepatocellular carcinoma not amenable to repeated resection or radiofrequency ablation

PURPOSE

To assess the efficacy and safety of computed tomography (CT)-guided high-dose-rate HDR) brachytherapy in treating recurrent hepatocellular carcinoma (HCC) not amenable to repeated resection or radiofrequency ablation.

MATERIALS AND METHODS

From January 2010 to January 2022, 38 patients (mean age, 70.1 years; SD ± 9.0 years) with 79 nodular and four diffuse intrahepatic HCC recurrences not amenable to repeated resection or radiofrequency ablation underwent CT-guided HDR brachytheapy in our department. Tumor response was evaluated by cross-sectional imaging 6 weeks after CT-guided HDR brachytherapy and every 3 months thereafter. Local tumor control (LTC), progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier curves (KPCs). Severity of procedure-related complications (PRCs) was classified as recommended by the Society of Interventional Radiology (SIR).

RESULTS

Patients were available for MRI evaluation for a mean follow-up of 33.1 months (SD, ±21.6 mm, range 4-86 months; median 29 months). Patients had a mean of 2.3 (SD, ±1.4) intrahepatic tumors. Mean tumor diameter was 43.2 mm (SD, ±19.6 mm). 13 of 38 (34.2%) patients showed local tumor progression after CT-guided HDR brachytherapy. Mean LTC was 29.3 months (SD, ±22.1). Distant tumor progression was seen in 12 patients (31.6%). The mean PFS was 20.8 months (SD, ±22.1). Estimated 1-, 3-, and 5-year PFS rates were 65.1%, 35.1% and 22.5%, respectively. 13 patients died during the follow-up period. Mean OS was 35.4 months (SD, ±21.7). Estimated 1-, 3-, and 5-year OS rates were 91.5%, 77.4% and 58.0%, respectively. SIR grade 1 complications were recorded in 8.6% (5/38) and SIR grade 2 complications in 3.4% (2/58) of interventions.

CONCLUSION

CT-guided HDR brachytherapy is a safe and efficient therapeutic option for managing large or critically located HCC recurrences in the remaining liver after prior hepatic resection.

CT-guided High-Dose-Rate Brachytherapy versus Transarterial Chemoembolization in Patients with Unresectable Hepatocellular Carcinoma

Background CT-guided high-dose-rate (HDR) brachytherapy (hereafter, HDR brachytherapy) has been shown to be safe and effective for patients with unresectable hepatocellular carcinoma (HCC), but studies comparing this therapy with other local-regional therapies are scarce. Purpose To compare patient outcomes of HDR brachytherapy and transarterial chemoembolization (TACE) in patients with unresectable HCC. Materials and Methods This multi-institutional retrospective study included consecutive treatment-naive adult patients with unresectable HCC who underwent either HDR brachytherapy or TACE between January 2010 and December 2022. Overall survival (OS) and progression-free survival (PFS) were compared between patients matched for clinical and tumor characteristics by propensity score matching. Not all patients who underwent TACE had PFS available; thus, a different set of patients was used for PFS and OS analysis for this treatment. Hazard ratios (HRs) were calculated from Kaplan-Meier survival curves. Results After propensity matching, 150 patients who underwent HDR brachytherapy (median age, 71 years [IQR, 63-77 years]; 117 males) and 150 patients who underwent TACE (OS analysis median age, 70 years [IQR, 63-77 years]; 119 male; PFS analysis median age, 68 years [IQR: 63-76 years]; 119 male) were analyzed. Hazard of death was higher in the TACE versus HDR brachytherapy group (HR, 4.04; P < .001). Median estimated PFS was 32.8 months (95% CI: 12.5, 58.7) in the HDR brachytherapy group and 11.6 months (95% CI: 4.9, 22.7) in the TACE group. Hazard of disease progression was higher in the TACE versus HDR brachytherapy group (HR, 2.23; P < .001). Conclusion In selected treatment-naive patients with unresectable HCC, treatment with CT-guided HDR brachytherapy led to improved OS and PFS compared with TACE. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Chapiro in this issue.

Can alternative liver function scores facilitate the establishment of an indication for radioablative therapy in patients with hepatocellular carcinoma?

BACKGROUND AND PURPOSE

ALBI and IBI are new scores to evaluate the liver function in patients with hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the prognostic abilities of those scores in patients treated with interstitial brachytherapy (iBT).

MATERIALS AND METHODS

190 patients treated with iBT between 01.01.2006 and 01.01.2018 were included in this study. The clinical target dose was 15 Gy. The patients were all in Child-Pugh stadium A or B and across the Barcelona Clinic Liver Cancer (BCLC) Stages 0-C. Retrospectively ALBI and IBI were calculated pre- and post-therapeutic until 6 months after iBT. Hazards ratios were calculated, and p values corrected using the false discovery rate according to Benjamini and Hochberg.

RESULTS

The median overall survival was 23.5 months (CI 19-28.5 months), and the median progression-free survival was 7.5 months (CI 6-9 months). Elevated ALBI showed a significantly higher risk to die with a hazard ratio (HR) of 2.010 (ALBI 2 vs. 1) and 4082 (ALBI 3 vs. 1), respectively. The IBI did also show a higher risk with an HR of 1.816 (IBI 1 vs. 0) and 4608 (IBI 2 vs. 0), respectively. Even 3 months after therapy elevated ALBI and IBI showed poor overall survival. Concerning progression-free survival, ALBI and IBI could not provide any relevant additional information.

CONCLUSION

ALBI and IBI are useful tools to predict the overall survival in patients treated with iBT and might be helpful to assign the patients to the appropriate therapy.

Local tumor control of intermediate and advanced stage hepatocellular carcinoma after local ablative treatment with image-guided interstitial high-dose-rate brachytherapy: A subgroup analysis of 286 HCC nodules

PURPOSE

Image-guided interstitial high-dose-rate brachytherapy (iBT) has been demonstrated to offer high local tumor control rates (LTC) of >90% after local ablation of intermediate and advanced hepatocellular carcinoma (HCC; BCLC B and C). The purpose of this study was to show the efficacy of iBT stratified by subgroups and to identify clinical characteristics associated with superior local tumor control (LTC) based on a highly heterogenous patient population METHODS AND MATERIALS: A cumulative number of 286 HCC nodules in 107 patients were retrospectively analyzed. Clinical and imaging follow-ups were conducted every 3 months after treatment. Analyzed clinical factors were: etiology, presence of liver cirrhosis, radiographic features, lesion size, pretreatment, administered dose, presence of portal hypertension, portal vein thrombosis, and level of alpha-fetoprotein (AFP).

RESULTS

LTC rate was 88.8% for a median follow-up of 14.3 months (range 3-81 months; 95% CI: 85-92%). Median minimal enclosing tumor dose (D100) was 16.1 Gy (range 7.1-30.3 Gy; reference dose 15 Gy). Subgroup analysis showed significant fewer local recurrences for alcoholic liver disease (ALD)-related HCCs compared to those related to other causes of liver cirrhosis (nonalcoholic fatty liver disease, virus-related liver cirrhosis and other causes) (p = 0.015). LTC was significantly lower after prior surgical resection (p = 0.046). No significant variance was observed for the applied D100 in each group or for all other clinical factors tested.

CONCLUSIONS

IBT achieves high LTC rates across treated subgroups. However, further studies should particularly address the possible impact of underlying etiology on local recurrence with emphasis on a possible higher radiosensitivity of ALD-related HCCs.

Clinical efficacy of CT-guided 125I brachytherapy in patients with local residual or recurrent hepatocellular carcinoma after thermal ablation

OBJECTIVES

Treatment methods of local residual or recurrent hepatocellular carcinoma (HCC) after thermal ablation are limited. Therefore, our study aimed to explore the efficacy and prognostic factors of ¹²⁵I brachytherapy for local residual or recurrent lesion after thermal ablation.

METHODS

A total of 114 patients with 212 local residual or recurrent HCC tumors after thermal ablation underwent ¹²⁵I brachytherapy. Local progression-free survival (LPFS) and prognostic factors were analyzed by Kaplan-Meier curves and the Cox model.

RESULTS

After a 6-month follow-up, the percentage of patients who achieved complete response (CR), partial response (PR), and stable disease (SD) was 57%, 13.2%, and 5.2%, respectively. The 1-, 2-, and 3-year LPFS rates were 58.7%, 50.0%, and 41.2%, respectively. Portal vein tumor thrombus (PVTT) (p = 0.03), the number of intrahepatic tumors (p = 0.01), and AFP level (p = 0.02) were independent risk factors for local tumor progression (LTP). The median LPFS in patients without PVTT (22 months) was much longer compared to those with PVTT (10 months). The median LPFS in patients with less than three intrahepatic lesions improved from 17 to 24 months. The median LPFS was only 5 months in the high AFP group, but was prolonged with a decrease in AFP level (24 months). No severe complications were recorded. All complications were controllable and treatable.

CONCLUSIONS

CT-guided ¹²⁵I brachytherapy was a safe and effective treatment for patients with local residual or recurrent HCC after thermal ablation to improve local control rate.

Pathological complete response with immunotherapy and brachytherapy to 15 metastatic liver lesions in a single patient

Materials & methods:

High dose rate interstitial brachytherapy (HDR-IBT) treatment plan for 15 metastatic liver lesions in a patient with pancreatic cancer was retrieved and analyzed for liver dose parameters and diaphragm dose. Serial ¹⁸F-FDG PET-CT scans were reviewed for disease response assessment and left liver lobe volume. Serial laboratory records were analyzed for liver parameters.

Results:

Left liver lobe volume increased from 241 cm³ pre-HDR-IBT to estimated 600 cm³ after seven sessions of HDR-IBT. Metabolic complete response (CR) and subsequently pathological CR was confirmed in the right hepatotectomy specimen for all the 15 PET-CT avid lesions treated with HDR-IBT. Maximum diaphragm dose in a single fraction was 82 Gy. The liver parameters were stable and patient did not develop radiation induced liver disease.

Discussion:

This is the largest reported series of HDR-IBT to liver lesions in a single patient. This first ever reported combined treatment of immunotherapy (IT) and HDR-IBT had likely rendered this patient disease free both at local the liver and systemically. Metabolic CR by PET-CT can be seen as early as 46 days after HDR-IBT. Diaphragm can tolerate very high doses of radiation and repeated treatment.

Conclusion:

In this patient HDR-IBT for multiple liver lesions with IT is well tolerated. PET-CT can be used for response assessment of HDR-IBT liver. Synergistic effect of IT with HDR-IBT and it’s role as bridging for liver resection has clinical potential and should be further studied in prospective trials.

Salvage 125I brachytherapy for liver metastases of colorectal cancer in anatomically challenging locations after failure of systemic chemotherapy-A retrospective study

PURPSOE

Colorectal cancer liver metastasis (CCLM) in anatomically challenging locations is difficult to treat. This retrospective study aimed to evaluate the effectiveness and safety of permanent ¹²⁵I seeds implantation (ISI) for treatment of CCLM in anatomically challenging locations after failure of systemic chemotherapy.

METHODS AND MATERIALS

A total of 31 liver metastases (in 25 patients) were treated by ISI under computerized tomography guidance from January 2011 to December 2017. Post-treatment follow-up was for 40 months. Adverse events were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Tumor response was evaluated by the mRECIST criteria. Objective response rate, overall survival rate, and complications were retrospectively analyzed.

RESULTS

All ISI procedures were performed successfully. Most patients only complained of fatigue and mild pain after ISI. Only one patient had liver rupture during the procedure. Serum alanine aminotransferase and aspartate aminotransferase levels at 1 month after ISI were not significantly different from pre-procedure levels (p > 0.05). Computed tomography at 6 months after ISI treatment showed completed response in 11 (11/31, 35.5%) lesions, partial response in 14 (14/31, 45.2%) lesions, stable disease in 4 (4/31, 12.9%) lesions, and disease progression in 2 (2/31, 6.5%) lesions; thus, the objective response rate was 80.6%. Median survival was for 12 months. The 1 and 2 year overall survival rates were 52.0% and 20.0%, respectively.

CONCLUSIONS

¹²⁵I seeds implantation for CCLM in anatomically challenging locations is safe and effective. Survival benefit is limited in the salvage setting where patients have high intrahepatic tumor load after failed systemic chemotherapy.

Narrative Review of High-Dose-Rate Interstitial Brachytherapy in Primary or Secondary Liver Tumors

The optimal management of intrahepatic malignancies involves a multidisciplinary approach. Although surgical resection has been considered the only curative approach, the use of several minimally invasive ablative techniques has dramatically increased the last two decades, mainly due to the fact that they provide similar oncological results with significantly decreased morbidity. Among these modalities, interstitial liver brachytherapy, probably the most flexible liver ablative method, with excellent clinical data on its safety and effectiveness, is frequently not even mentioned as an option in the current peer reviewed literature and guidelines. Brachytherapy is a type of radiotherapy utilizing radionuclides that are directly inserted into the tumor. Compared to external beam radiation therapy, brachytherapy has the potential to deliver an ablative radiation dose over a short period of time, with the advantage of a rapid dose fall-off, that allows for sparing of adjacent healthy tissue. For numerous malignancies such as skin, gynecological, breast, prostate, head and neck, bladder, liver and soft-tissue tumors, brachytherapy as a monotherapy or combined with external beam radiation therapy, has become a standard treatment for many decades. This review article aims to describe the high-dose-rate liver brachytherapy technique, its selection criteria, present its advantages and disadvantages, as well as the available clinical data, in order to help physicians to explore and hopefully introduce liver brachytherapy into their clinical routine.

Interstitial High-Dose-Rate Brachytherapy of Liver Metastases in Oligometastatic Patients

Simple Summary

Local ablative treatments have emerged as a promising treatment strategy for patients with oligometastatic disease. Interstitial brachytherapy (iBT) is one of the locally ablative treatment options for unresectable liver metastases in oligometastatic disease. We report the feasibility and oncologic outcome of 141 iBT treatments of 244 oligometastatic liver metastases performed in patients with limited tumor burdens in a high-volume center. iBT was feasible, safe and effective in the treatment of oligometastatic liver metastases with good local control rates and low toxicity. Histology and total tumor volume had an impact on local control rates.

Abstract

Local ablative treatments have emerged as a promising treatment strategy for patients with oligometastatic disease. Among others, interstitial brachytherapy (iBT) is an upcoming treatment option for unresectable liver metastases. We report the feasibility and oncologic outcome of iBT of oligometastatic liver metastases performed in patients with limited tumor burdens in a high-volume center. Patients undergoing iBT between August 2017and March 2019 were included. A retrospective analysis of patient outcomes and treatment complications was performed. Patients treated for metastatic colorectal carcinoma (CRC) were compared to other histologies. A total of 141 iBT procedures were performed in 106 patients (male:52; female:54) and 244 liver metastases. Overall, 51% (54/106) of patients had a diagnosis of metastatic CRC. The median follow-up was 9 months, and overall survival (OS) was 92.3% at 6 months and 76.3% at 12 months. Local-relapse-free survival (LRFS) was 88.4% at 6 months and 71.5% at 12 months, with a significant difference between patients with CRC (84.1% and 50.6%) versus other histologies (92.4% and 92.4%, p < 0.001). A sub-group analysis showed a significant advantage in patients with CRC receiving a minimal dose (D100) of 20 Gy to the planning target volume. Treatments of smaller total liver-tumor volumes (<18 ccm) resulted in better LRFS rates. iBT is a safe and effective treatment approach for oligometastatic liver disease. A higher treatment dose is needed for patients with CRC. Moreover, lower metastatic burdens may be favorable for LRFS. Prospective studies are needed to assess the role of iBT in the oligometastatic setting as an alternative to other local ablative treatment approaches in patients with liver metastases.

Image-Guided Local Treatment for Unresectable Intrahepatic Cholangiocarcinoma-Role of Interventional Radiology

Intrahepatic cholangiocarcinoma is a highly aggressive malignancy with an increasing incidence in recent years. Prognosis is poor and most patients are not eligible for resection at the time of initial diagnosis due to the anatomic location, inadequate hepatic reserve, limiting comorbidities or metastatic disease. Several locoregional therapies from the field of interventional radiology exist for patients who are not amenable for surgery, or in case of local recurrence as a single treatment modality or combined with systemic treatment. To date, evidence is limited, with most conclusions drawn from single-center studies with small patient cohorts, often treated in the salvage situation or for local recurrence after initial resection. Nevertheless, the results are promising and suggest a survival benefit in selected patients. This narrative review focuses on the use of different locoregional treatment options for intrahepatic cholangiocarcinoma.

HDR Brachytherapy and SBRT as Bridging Therapy to Liver Transplantation in HCC Patients: A Single-Center Experience

Background

In the treatment of patients with HCC awaiting liver transplantation (LT), local ablative treatments (LAT) are available either for downstaging or as bridging treatment. We present our clinical experience with both available radiation-based techniques, brachytherapy (BT), and stereotactic body radiotherapy (SBRT).

Methods

All patients diagnosed with HCC and who were treated with BT or SBRT at our institution between 2011 and 2018 were retrospectively reviewed. The current analysis included all patients who subsequently underwent LT.

Results

A total of 14 patients (male=9; female=5) were evaluated. Seven underwent BT for bridging before LT, and seven were treated with SBRT. BT was performed with a prescribed dose of 1 × 15 Gy, while SBRT was applied with 37 Gy (65%-iso) in three fractions in six patients, and one patient was treated with 54 Gy (100%-iso) in nine fractions. The treatment was generally well tolerated. One case of grade 3 bleeding was reported after BT, and one case of liver failure occurred following SBRT. All patients underwent LT after a median time interval of 152 days (range 47–311) after BT and 202 days (range 44–775) following SBRT. In eight cases, no viable tumor was found in the explanted liver, while four liver specimens showed vital tumor. The median follow-up after SBRT was 41 months and 17 months following BT. Overall, no hepatic HCC recurrence occurred following LT.

Conclusion

Both SBRT and BT are feasible and well tolerated as bridging to LT when applied with caution in patients with impaired liver function. Radiation-based treatments can close the gap for patients not suitable for other locally ablative treatment options.

Case Report-Staged brachytherapy achieving complete metabolic response in unresectable oligometastatic colorectal cancer to the liver

Liver is the most common site for metastasis from colorectal cancer (CRC). Non-surgical treatment options for oligometastatic CRC confined to the liver which represents an intermediate state in the metastatic cascade are fast expanding. Currently, several liver-directed local therapeutic options are available, such as hepatic arterial infusion (HAI) therapy, radio-frequency ablation (RFA), transarterial chemoembolization (TACE), stereotactic body radiotherapy and high dose rate brachytherapy (HDRBT). Many factors such as patient's fitness, liver function (LF), tumour size, location of the tumour in the liver and scheduling of systemic therapy need to be considered when selecting patients for surgery or local liver-directed therapy. This case report illustrates a successful local treatment with staged HDRBT for a large and unresectable, liver only oligometastatic disease from CRC. This patient underwent 4 cycles of chemotherapy (FOLFOX 4) followed by primary tumour resection and first stage of HDRBT to liver for a residual 14 cm tumour after the chemotherapy. After completing a further 4 cycles of chemotherapy with the same regimen, the tumour remained stable at 8 cm. She underwent a second stage of HDRBT to the same lesion and a repeat PET-CT scan done 8 weeks after the second HDRBT showed complete metabolic response. To our knowledge, this is the largest CRC metastatic liver lesion that has been successfully treated with HDRB.

Multi-modal and sequential treatment of liver cancer and its impact on the gastrointestinal tract

Hepatic tumors include hepatocellular cancer (HCC) and cholangiocarcinoma (CC), a small subgroup of tumors (approx. 1%) are classified as combined hepatocellularcholangiocellular carcinomas. Different stage-dependent therapeutic approaches comprise resection, local ablative techniques, locoregional therapies, systemic treatment, liver transplantation in selected cases and possible combination of these treatment modalities. This review summarizes current knowledge on multi-modal treatment strategies for liver cancer focusing on gastrointestinal side effects.

Treatment of metastatic gastric adenocarcinoma with image-guided high-dose rate, interstitial brachytherapy as second-line or salvage therapy

PURPOSE

We aimed to evaluate the safety and effectiveness of image-guided high-dose rate interstitial brachytherapy (iBT) for the treatment of patients with hepatic, lymphatic, and pancreatic metastases originating from gastric cancer, an entity rarely surgically treatable with curative intent.

METHODS

Twelve patients with a cumulative number of 36 metastases (29 liver, 2 pancreatic, 5 lymph node) from histologically proven gastric adenocarcinoma received iBT between 2010 and 2016 and were retrospectively analyzed. Every patient underwent palliative chemotherapy prior to iBT. The iBT procedure employs a temporarily, intratumorally placed iridium-192 source in a single fraction with the goal of tumor cell eradication. Effectiveness was assessed clinically and by radiologic imaging every three months.

RESULTS

Local tumor control was achieved in 32 of all treated metastases (89%). Four lesions showed a local recurrence after 7 months. Lesion sizes varied from 9 to 102 mm with a median of 20 mm. The median progression-free survival was 6.6 months (range, 1.8-46.8 months). The median overall survival was 11.4 months (range, 5-47 months). One patient suffered a major complication following iBT, hepatic hematoma and abscess (Common Terminology Criteria for Adverse Events grade 3), successfully dealt with by transcutaneous drainage.

CONCLUSION

iBT is an overall safe procedure, which facilitates high rates of local tumor control in treatment of metastatic gastric adenocarcinoma. Compared with surgical metastasectomy, similar overall survival rates could be achieved in our patient collective after iBT application.

First report on extended distance between tumor lesion and adjacent organs at risk using interventionally applied balloon catheters: a simple procedure to optimize clinical target volume covering effective isodose in interstitial high-dose-rate brachytherapy of liver malignomas

Purpose

Organs at risk (OARs), which are very close to a clinical target volume (CTV), can compromise effective tumor irradiation. The present study investigated the feasibility and safety of a novel approach, in particular, the extent of the dosimetric effect of distancing CTV from adjacent OARs by means of interventionally applied balloon catheters.

Material and methods

Patients with peripheral hepatic malignancies, in whom the critical proximity of an OAR to the CTV in the assessment by contrast-enhanced magnetic resonance imaging (MRI) scans and the preplanning process were included. Additionally, patients underwent placement of an interventional balloon catheter during computed tomography (CT)-guided application of interstitial brachytherapy (iBT) catheters inserted into the tissue between hepatic capsule and adjacent OAR. The virtual position of an OAR without balloon catheter was anticipated and contoured in addition to contouring of CTV and OAR. The calculated dose values for CTV as well as 1 cc of the relevant OAR (D_1cc) with and without balloon were recorded. The D_1cc of the realized irradiation plan was statistically compared to the D_1cc of the virtually contoured OARs.

Results

In 31 cases, at least one balloon catheter was administered. The mean D_1cc of the OAR in the group with balloon(s) was 12.6 Gy compared with 16 Gy in the virtual cohort without the device, therefore significantly lower (p < 0.001). Overall, there were no acute complications. Severe (> 2 CTCAEv4.03) late complications observed in 3/31 (9.6%) patients during follow-up period after brachytherapy were most certainly not due to the balloon application. Side effects were probably associated with pre-existing serious diseases and potentially additional local late effects of the irradiation in general rather than with the balloon catheters.

Conclusions

The distancing of the adjacent OARs allows a higher D₁₀₀ value of CTV, therefore allowing for more efficient local control.

Repeating of local therapy of distant metastases increases overall survival in patients with synchronous metastasized rectal cancer-a monocentric analysis

PURPOSE

The aim was to evaluate the outcome of treatment-naive patients with synchronous metastatic rectal cancer after chemotherapy with FOLFOXIRI followed by local therapeutic procedures of all tumor lesions as complete as possible.

METHODS

We reviewed data of 30 patients with synchronous distant metastatic rectal cancer who underwent chemotherapy with FOLFOXIRI and subsequent local therapy in our institution.

RESULTS

Median follow-up was 28 months (range: 8; 74). Cumulative overall survival (OS) and progression-free survival (PFS) was 93.3, 76.9, 55.6% and 46.2, 29.7, 29.7% after 1, 2, 4 years. Non-response to chemotherapy with FOLFOXIRI was associated with a highly significant decreased OS (p < 0.0001). The consistent use of local ablative procedures led to a statistically significant increase in OS (p < 0.0001), but not in PFS (p = 0.635). Patients with ≤ 4 distant metastases showed a better OS (p = 0.033).

CONCLUSIONS

Response to intensified first-line chemotherapy with FOLFOXIRI, treatment of the primary rectal tumor, and repeated thorough local ablative procedures in patients with synchronous metastasized rectal cancer may lead to long-term survival, even in a subset of patients with unresectable disease at initial diagnosis.

Accuracy assessment of a potential clinical use of navigation-guided intra-operative liver metastasis brachytherapy-a planning study

For patients with inoperable liver metastases, intra-operative liver high dose-rate brachytherapy (HDR-BT) is a promising technology enabling delivery of a high radiation dose to the tumor, while sparing healthy tissue. Liver brachytherapy has been described in the literature as safe and effective for the treatment of primary or secondary hepatic malignancies. It is preferred over other ablative techniques for lesions that are either larger than 4 cm or located in close proximity to large vessels or the common bile duct. In contrast to external beam radiation techniques, organ movements do not affect the size of the irradiated volume in intra-operative HDR-BT and new technical solutions exist to support image guidance for intra-operative HDR-BT. We have retrospectively analyzed anonymized CT datasets of 5 patients who underwent open liver surgery (resection and/or ablation) in order to test whether the accuracy of a new image-guidance method specifically adapted for intra-operative HDR-BT is high enough to use it in similar situations and whether patients could potentially benefit from navigation-guided intra-operative needle placement for liver HDR-BT.