Conformal Radiotherapy of the Dominant Liver Metastasis

Intra-Arterial Super-Selective Delivery of Yttrium-90 for the Treatment of Recurrent Glioblastoma: In Silico Proof of Concept with Feasibility and Safety Analysis

Background: Intra-arterial cerebral infusion (IACI) of radiotherapeutics is a promising treatment for glioblastoma (GBM) recurrence. We investigated the in silico feasibility and safety of Yttrium-90-Poly(vinyl alcohol)-Microbubble (90Y-PVA-MB) IACI in patients with recurrent GBM and compared the results with those of external beam radiation therapy (EBRT). Methods: Contrast-enhanced T1-weighted magnetic resonance imaging (T1W-MRI) was used to delineate the tumor volumes and CT scans were used to automatically segment the organs at risk in nine patients with recurrent GBM. Volumetric Modulated Arc Therapy (VMAT) treatment plans were generated using a clinical treatment planning system. Assuming the relative intensity of each voxel from the MR-T1W as a valid surrogate for the post-IACI 90Y-PVA-MB distribution, a specific 90Y dose voxel kernel was obtained through Monte Carlo (MC) simulations and convolved with the MRI, resulting in a 90Y-PVA-MB-based dose distribution that was then compared with the VMAT plans. Results: The physical dose distribution obtained from the simulation of 1GBq of 90Y-PVA-MBs was rescaled to ensure that 95% of the prescribed dose was delivered to 95% or 99% of the target (i.e., A95% and A99%, respectively). The calculated activities were A95% = 269.2 [63.6-2334.1] MBq and A99% = 370.6 [93.8-3315.2] MBq, while the mean doses to the target were 58.2 [58.0-60.0] Gy for VMAT, and 123.1 [106.9-153.9] Gy and 170.1 [145.9-223.8] Gy for A95% and A99%, respectively. Additionally, non-target brain tissue was spared in the 90Y-PVA-MB treatment compared to the VMAT approach, with a median [range] of mean doses of 12.5 [12.0-23.0] Gy for VMAT, and 0.6 [0.2-1.0] Gy and 0.9 [0.3-1.5] Gy for the 90Y treatments assuming A95% and A99%, respectively. Conclusions: 90Y-PVA-MB IACI using MR-T1W appears to be feasible and safe, as it enables the delivery of higher doses to tumors and lower doses to non-target volumes compared to the VMAT approach.

American Radium Society Appropriate Use Criteria for the use of liver-directed therapies for nonsurgical management of liver metastases: Systematic review and guidelines

The liver is a common site of cancer metastases. Systemic therapy is widely accepted as the standard treatment for liver metastases (LM), although select patients with liver oligometastases may be candidates for potentially curative liver resection. Recent data support the role of nonsurgical local therapies such as ablation, external beam radiotherapy, embolization, and hepatic artery infusion therapy for management of LM. Additionally, for patients with advanced, symptomatic LM, local therapies may provide palliative benefit. The American Radium Society gastrointestinal expert panel, including members representing radiation oncology, interventional radiology, surgical oncology, and medical oncology, performed a systemic review and developed Appropriate Use Criteria for the use of nonsurgical local therapies for LM. Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology was used. These studies were used to inform the expert panel, which then rated the appropriateness of various treatments in seven representative clinical scenarios through a well-established consensus methodology (modified Delphi). A summary of recommendations is outlined to guide practitioners on the use of nonsurgical local therapies for patients with LM.

Pharmacological prevention strategy for capecitabine-induced hand-foot syndrome: A network meta-analysis of randomized control trials

Capecitabine-induced hand-foot syndrome (HFS) is common in clinical practice. There are many regimens used to prevent HFS. However, the most effective preventive regimen has not yet been identified. Thus, we conducted a network meta-analysis to investigate the best preventive regimen for HFS. The PRISMA-NMA guidelines were used in this study. The PubMed, Cochrane, and Embase databases were searched. The main endpoint was set as HFS of National Cancer Institute grade 2 or more. We included only randomized control trials. The P-score was used to rank the regimens. Among all the regimens, topical silymarin had the best preventive ability compared with the placebo (OR: 0.08; 95% CI: 0.01-0.71). The other identified effective regimen included pyridoxine (400 mg) and celecoxib; compared with the placebo, the odds ratio was 0.27 (95% CI: 0.08-0.91) and 0.41 (95% CI: 0.18-0.95), respectively. Topical silymarin is the most useful regimen for preventing capecitabine-induced HFS.

Rs13293512 polymorphism located in the promoter region of let-7 is associated with increased risk of radiation enteritis in colorectal cancer

RE (Radiation enteritis) has been characterized by the inflammation reaction, and in this study, we aim to explore inflammatory cytokines and underlying mechanism involved in the pathogenesis of RE. Luciferase assay was performed to explore whether polymorphism affected the expression of let-7, and also validated let-7 directly regulated f IL-6 expression. Then Elisa was performed to study the mechanism of rs13293512 polymorphism associated with enteritis occurrence. And Western-blot and real-time PCR were performed to verify the relationship between let-7 and IL-6. 380 colorectal cancer patients were recruited, and all participants were genotyped. We found that occurrence probability of enteritis patients carried CC genotype (32%) was much higher than that in TT and TC groups (15%). In addition, we showed that the presence of the minor (C) allele of the polymorphism in the promoter region of let-7 substantially reduced the transcription activity of let-7, furthermore, we validated that let-7 directly regulated IL-6 expression by using luciferase reporter system. Moreover, IL-6 was highly expressed in peripheral blood and colonic mucosa samples genotyped as CC compared to those in TT and TC groups, furthermore, IL-6 was highly expressed in peripheral blood and colonic mucosa samples from participants with enteritis than without enteritis, whereas let-7 was highly expressed in peripheral blood and colonic mucosa samples genotyped as TT and TC compared to those in CC groups. Let-7 polymorphism (rs13293512) was associated with risk of RE in the colorectal cancer patients who received radiotherapy.

Investigation of Copper Cysteamine Nanoparticles as a New Type of Radiosensitiers for Colorectal Carcinoma Treatment

Copper Cysteamine (Cu-Cy) is a new photosensitizer and a novel radiosensitizer that can be activated by light, X-ray and microwave to produce singlet oxygen for cancer treatment. However, the killing mechanism of Cu-Cy nanoparticles on cancer cells is not clear yet and Cu-Cy nanoparticles as novel radiosensitizers have never been tested on colorectal cancers. Here, for the first time, we investigate the treatment efficiency of Cu-Cy nanoparticles on SW620 colorectal cells and elucidate the underlying mechanisms of the effects. The results show that X-ray activated Cu-Cy nanoparticles may kill SW620 cancerscells is in a dose-dependent manner. The JC-1 staining shows the mitochondrial membrane potential is decreased after the treatment. The observations confirm that Cu-Cy nanoparticles may improve X-ray radiotherapy on cancer treatment and X-ray activated Cu-Cy nanoparticles can be efficiently destroy colorectal cancer cells by inducing apoptosis as well as autophagy. As a new type of radiosensitizers and photosensitizers, Cu-Cy nanoparticles have a good potential for colorectal cancer treatment and the discovery of autophagy induced by X-ray irradiated Cu-Cy nanoparticles sheds a good insight to the mechanism of Cu-Cy for cancer treatment as a new radiosensitizers.

Autophagy inhibition enhances photocytotoxicity of Photosan-II in human colorectal cancer cells

Photodynamic therapy (PDT) has emerged as an attractive therapeutic treatment for colorectal cancer because of its accessibility through endoscopy and its ability to selectively target tumors without destroying the anatomical integrity of the colon. We therefore investigated the therapeutic relevance of the interplay between autophagy and apoptosis in Photosan-II (PS-II)-mediated photodynamic therapy (PS-PDT) in in vitro and in vivo models for human colorectal cancer. We observed that PS-PDT-induced dose-dependently triggered apoptosis and autophagy in both SW620 and HCT116 cells. PS-PDT-treated SW620 cells exhibited nuclear condensation and increased levels of cleaved caspase-3, PARP and Bax, which is reminiscent of apoptosis. PS-PDT also induced autophagic vacuoles, double membrane autophagosome structures and the autophagy-related proteins P62, Bcl-2, ATG7 and LC3-II. In addition, the AKT-mTOR pathway was downregulated, while AMPK was upregulated in PS-PDT-treated cells. Inhibiting autophagy using chloroquine or by downregulating ATG7 using shRNA further upregulated apoptosis, suggesting autophagy was probably was protective to PS-PDT-treated tumor cells. In vivo relevance was demonstrated when a combination of chloroquine and PS-PDT significantly reduced the tumor size in a xenograft mice model. Our findings demonstrate that combination therapy using PS-PDT and autophagy inhibitors may be an effective approach to treating colorectal cancer patients.

Biologic mesh spacer placement facilitates safe delivery of dose-intense radiation therapy: A novel treatment option for unresectable liver tumors

INTRODUCTION

Patients with unresectable liver tumors who fail initial treatment modalities have a poor prognosis (<1 yr). Although effective, delivery of high dose radiation therapy to these tumors is limited by proximity of radiosensitive bowel. We have previously reported that placement of a biologic mesh spacer (BMS) can effectively displace the bowel allowing for dose-intense radiation to be delivered with low short-term toxicity. The purpose of this study was to assess and report the long-term safety and oncologic outcomes of this cohort.

METHODS

From 2012 to 2014 seven patients with unresectable hepatic malignancy (6 IHCC, 1 CRLM) underwent BMS (acellular human dermis) placement (2 open, 5 MIS) prior to radiation therapy. Prospective registry data were reviewed for tumor and treatment details, progression, metastasis and survival. RTOG guidelines were used to define radiation toxicities.

RESULTS

Mean patient age was 50.4 years (30-62 years) and 4 patients were male (57.1%). Prior to surgery, all patients had been treated for an average of 12.5 months with surgery, chemotherapy, radiation and/or TACE. After surgery, all patients recovered well and received a mean radiation dose of 76.1 Gy (58.1-100 Gy) over 13-25 fractions. 1 patient received SBRT; 4 fractions, 10 Gy each. Maximum dose delivered was 100 Gy (Biologic Equivalent Dose of 140 Gy, α/β = 10). Mean time to initiation of radiation therapy was 24 days (12-48 days) from surgery. No significant GI toxicity was recorded, and no GI bleeding or ulcers were observed. Mean follow-up after XRT was 18.2 months (5.5-31 months). Three patients had no loco-regional progression of disease. 2 patients had infield progression of liver disease and another had progressive lymphadenopathy. 3 patients developed pulmonary metastasis, at a mean time to distant failure of 3 months. There are 4 survivors over 2-years from surgery.

CONCLUSION

For patients with unresectable liver tumors, placement of a BMS enhances the safety and efficacy of high-dose radiotherapy, providing a survival benefit via delay in time to progression compared to traditional treatments with no significant short or long term GI toxicity.

Radioembolization of hepatocarcinoma with (90)Y glass microspheres: development of an individualized treatment planning strategy based on dosimetry and radiobiology

PURPOSE

The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on (99m)Tc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images.

METHODS

We performed retrospective dosimetry of the standard TheraSphere® treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50% and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on (99m)Tc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of (99m)Tc-MAA and (90)Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS™ by Philips). STRATOS™ absorbed dose calculation was validated for (90)Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BEDave) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were derived. The area under the curve (AUC) of the receiver-operating characteristic (ROC) curve was used as a figure of merit to identify the methodology which gave the best separation in terms of dosimetry between responding and non-responding lesions and liver decompensated vs non-decompensated liver treatment.

RESULTS

MAA and (90)Y biodistributions were not different (71% of cases), different in 23% and uncertain in 6%. Response correlated with absorbed dose (Spearman's r from 0.48 to 0.69). Responding vs non-responding lesion absorbed doses were well separated, regardless of the methodology adopted (p = 0.0001, AUC from 0.75 to 0.87). EUBED gave significantly better separation with respect to mean dose (AUC = 0.87 vs 0.80, z = 2.07). Segmentation on SPECT gave better separation than on SPECT/CT. TCP(50%) was at 250 Gy for small lesion volumes (<10 cc) and higher than 1,000 Gy for large lesions (>10 cc). Apparent radiosensitivity values from TCP were around 0.003/Gy, a factor of 3-5 lower than in EBRT, as found by other authors. The dose-rate effect was negligible: a purely linear model can be applied. Toxicity incidence was significantly larger for Child B7 patients (89 vs 14%, p < 0.0001), who were therefore excluded from dose-toxicity analysis. Child A toxic vs non-toxic treatments were significantly separated in terms of dose averaged on whole non-tumoural parenchyma (including non-irradiated regions) with AUC from 0.73 to 0.94. TD50 was ≈ 100 Gy. No methodology was superior to parenchyma mean dose, which therefore can be used for planning, with a limit of TD15 ≈ 75 Gy.

CONCLUSION

A dosimetric treatment planning criterion for Child A patients without complete obstruction of the portal vein was developed.

A hepatic dose-toxicity model opening the way toward individualized radioembolization planning

The 50% normal-tissue complication probability (NTCP) after lobar irradiation of the liver results in highly variable biologic effective doses depending on the modality used: a biologic effective dose for 50% (BED50) of 115, 93, and 250 Gy for external-beam radiotherapy, resin microsphere radioembolization, and glass microsphere radioembolization, respectively. This misunderstood property has made it difficult to predict the maximal tolerable dose as a function of microsphere activity and targeted liver volume. The evolution toward more selective catheterization techniques, resulting in more variable targeted volumes, makes it urgent to solve this issue.

METHODS

We computed by Monte Carlo simulations the microsphere distribution in the portal triads based on microsphere transport dynamics through a synthetically grown hepatic arterial tree. Afterward, the microscale dose distribution was computed using a dose deposition kernel. We showed that the equivalent uniform dose cannot handle microscale dosimetry and fails to solve the discordance between the BED50 values. Consequently, we developed a new radiobiologic model to compute the liver NTCP from the microscale dose distribution.

RESULTS

The new model explains all the observed BED50 values and provides a way to compute the hepatic dose-toxicity relationship as a function of microsphere activity and targeted liver volume. The NTCP obtained is in agreement with the data reported from clinical radioembolization studies.

CONCLUSION

The results should encourage interventional radiologists to fine-tune the delivered dose to the liver as a function of the targeted volume. The present model could be used as the backbone of the treatment planning, allowing optimization of the absorbed dose to the tumors.

Percutaneous irreversible electroporation for the treatment of colorectal cancer liver metastases with a proposal for a new response evaluation system

PURPOSE

To describe an initial experience with irreversible electroporation (IRE) in patients with colorectal liver metastasis (CLM).

MATERIALS AND METHODS

A retrospective analysis of patients undergoing IRE for the management of CLM was performed. Procedures were done percutaneously under general anesthesia. Patients were then followed for adverse events, tumor response, and survival.

RESULTS

Between March 2010 and February 2013, 29 patients underwent percutaneous ablation of 58 tumors in 36 IRE sessions. Most patients (89%) had an absolute or relative contraindication to thermal ablation. The median age was 62 years, and the median time from diagnosis to IRE was 28 months. The median number of lesions treated per patient was two, and the median tumor size was 2.7 cm. Patients had received previous chemotherapy regimens (range, 1-5 per patient). A new Metabolic Imaging And Marker Integration response evaluation criteria was used for response assessment, and was a predictor of progression-free and overall survival. The 2-year progression-free survival rate was 18% (95% confidence interval, 0%-35%), and the 2-year overall survival rate was 62% (95% confidence interval, 37%-87%). Complications included arrhythmias (n = 1) and postprocedure pain (n = 1). Both patients recovered without sequelae.

CONCLUSIONS

Percutaneous IRE of CLM is feasible and safe. A new response evaluation system for colorectal cancer appears to be prognostic.

Radiobiologic optimization of combination radiopharmaceutical therapy applied to myeloablative treatment of non-Hodgkin lymphoma

Combination treatment is a hallmark of cancer therapy. Although the rationale for combination radiopharmaceutical therapy was described in the mid-1990s, such treatment strategies have only been implemented clinically recently and without a rigorous methodology for treatment optimization. Radiobiologic and quantitative imaging-based dosimetry tools are now available that enable rational implementation of combined targeted radiopharmaceutical therapy. Optimal implementation should simultaneously account for radiobiologic normal-organ tolerance while optimizing the ratio of 2 different radiopharmaceuticals required to maximize tumor control. We have developed such a methodology and applied it to hypothetical myeloablative treatment of non-Hodgkin lymphoma (NHL) patients using (131)I-tositumomab and (90)Y-ibritumomab tiuxetan.

METHODS

The range of potential administered activities (AAs) is limited by the normal-organ maximum-tolerated biologic effective doses (MTBEDs) arising from the combined radiopharmaceuticals. Dose-limiting normal organs are expected to be the lungs for (131)I-tositumomab and the liver for (90)Y-ibritumomab tiuxetan in myeloablative NHL treatment regimens. By plotting the limiting normal-organ constraints as a function of the AAs and calculating tumor biologic effective dose (BED) along the normal-organ MTBED limits, we obtained the optimal combination of activities. The model was tested using previously acquired patient normal-organ and tumor kinetic data and MTBED values taken from the literature.

RESULTS

The average AA value based solely on normal-organ constraints was 19.0 ± 8.2 GBq (range, 3.9-36.9 GBq) for (131)I-tositumomab and 2.77 ± 1.64 GBq (range, 0.42-7.54 GBq) for (90)Y-ibritumomab tiuxetan. Tumor BED optimization results were calculated and plotted as a function of AA for 5 different cases, established using patient normal-organ kinetics for the 2 radiopharmaceuticals. Results included AA ranges that would deliver 95% of the maximum tumor BED, allowing for informed inclusion of clinical considerations, such as a maximum-allowable (131)I administration.

CONCLUSION

A rational approach for combination radiopharmaceutical treatment has been developed within the framework of a proven 3-dimensional (3D) personalized dosimetry software, 3D-RD, and applied to the myeloablative treatment of NHL. We anticipate that combined radioisotope therapy will ultimately supplant single radioisotope therapy, much as combination chemotherapy has substantially replaced single-agent chemotherapy.

Safety and early efficacy of irreversible electroporation for hepatic tumors in proximity to vital structures

INTRODUCTION

Irreversible electroporation (IRE) has shown promise for ablation of lesions in proximity to vital structures in the preclinical setting. This study aims to evaluate the safety and efficacy of IRE for hepatic tumors in the clinical setting.

METHODS

An IRB approved prospective registry of patients undergoing IRE for hepatic tumors over a 2-year period. Factors analyzed included patient and tumor characteristics, treatment related complications, and local recurrence free survival (LRFS) for ablated lesions. LRFS was calculated according to Kaplan-Meier, with secondary analyses stratified by procedural approach (laparotomy, laparoscopy, and percutaneous) and tumor histology.

RESULTS

There were 44 patients undergoing 48 total IRE procedures, 20 colorectal mets, 14 hepatocellular, and 10 other metastatsis. Initial success was achieved in 46 (100%) treatments. Five patients had 9 adverse events, with all complications resolving within 30 days. LRFS at 3, 6, and 12 months was 97.4%, 94.6%, and 59.5%. There was a trend toward higher recurrence rates for tumors over 4 cm (HR 3.236, 95% CI: 0.585-17.891; P = 0.178).

CONCLUSIONS

IRE appears to be a safe treatment for hepatic tumors in proximity to vital structures. Further prospective evaluation is needed to determine the optimal effectiveness of IRE in relation to size and technique for IRE of the liver.

Scoring system predictive of survival for patients undergoing stereotactic body radiation therapy for liver tumors

Background

Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver tumors. This study evaluated outcomes after SBRT to identify prognostic variables and to develop a novel scoring system predictive of survival.

Methods

The medical records of 52 patients with a total of 85 liver lesions treated with SBRT from 2003 to 2010 were retrospectively reviewed. Twenty-four patients had 1 lesion; 27 had 2 or more. Thirteen lesions were primary tumors; 72 were metastases. Fiducials were placed in all patients prior to SBRT. The median prescribed dose was 30 Gy (range, 16 – 50 Gy) in a median of 3 fractions (range, 1–5).

Results

With median follow-up of 11.3 months, median overall survival (OS) was 12.5 months, and 1 year OS was 50.8%. In 42 patients with radiographic follow up, 1 year local control was 74.8%. On univariate analysis, number of lesions (p = 0.0243) and active extralesional disease (p < 0.0001) were predictive of OS; Karnofsky Performance Status (KPS) approached statistical significance (p = 0.0606). A scoring system for predicting survival was developed by allocating 1 point for each of the three following factors: active extralesional disease, 2 or more lesions, and KPS ≤ 80%. Score was associated with OS (p < 0.0001). For scores of 0, 1, 2 and 3, median survival intervals were 34, 12.5, 7.6, and 2.8 months, respectively.

Conclusions

SBRT offers a safe and feasible treatment option for liver tumors. A prognostic scoring system based on the number of liver lesions, activity of extralesional disease, and KPS predicts survival following SBRT and can be used as a guide for prospective validation and ultimately for treatment decision-making.

Stereotactic body radiation therapy for abdominal oligometastases: a biological and clinical review

Advances in imaging and biological targeting have led to the development of stereotactic body radiation therapy (SBRT) as an alternative treatment of extracranial oligometastases. New radiobiological concepts, such as ceramide-induced endothelial apoptosis after hypofractionated high-dose SBRT, and the identification of patients with oligometastatic disease by microRNA expression may yet lead to further developments. Key factors in SBRT are delivery of a high dose per fraction, proper patient positioning, target localisation, and management of breathing-related motion. Our review addresses the radiation doses and schedules used to treat liver, abdominal lymph node (LN) and adrenal gland oligometastases and treatment outcomes. Reported local control (LC) rates for liver and abdominal LN oligometastases are high (median 2-year actuarial LC: 61 -100% for liver oligometastases; 4-year actuarial LC: 68% in a study of abdominal LN oligometastases). Early toxicity is low-to-moderate; late adverse effects are rare. SBRT of adrenal gland oligometastases shows promising results in the case of isolated lesions. In conclusion, properly conducted SBRT procedures are a safe and effective treatment option for abdominal oligometastases.

Stereotactic body radiation therapy for liver metastases from colorectal cancer: analysis of safety, feasibility, and early outcomes

INTRODUCTION

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the U.S. Many patients with CRC develop hepatic metastases as the sole site of metastases. Historical treatment options were limited to resection or conventional radiation therapy. Stereotactic body radiation therapy (SBRT) has emerged as a rational treatment approach. This study reviews our experience with SBRT for patients with liver metastases from CRC.

MATERIALS AND METHODS

Fourteen histologically confirmed hepatic CRC metastases in 11 consecutive patients were identified between November, 2004 and June, 2009 at Georgetown University. All patients underwent CT-based treatment planning; a few also had MRI or PET/CT. All patients had fiducial markers placed under CT guidance and were treated using the CyberKnife system. Treatment response and toxicities were examined; survival and local control were evaluated.

RESULTS

Most patients were treated to a single hepatic lesion (n = 8), with a few treated to two lesions (n = 3). Median treatment volume was 99.7 cm(3), and lesions were treated to a median BED(10) of 49.7 Gy (range: 28-100.8 Gy). Median follow-up was 21 months; median survival was 16.1 months, with 2 year actuarial survival of 25.7%. One year local control was 72%. Among patients with post-treatment imaging, eight had stable disease (80%) and two had progressive disease (20%) at first follow-up. The most common grade 1-2 acute toxicities included nausea and alterations in liver function tests; there was one grade 3 toxicity (elevated bilirubin), and no grade 4-5 toxicities.

DISCUSSION

SBRT is safe and feasible for the treatment of limited hepatic metastases from CRC. Our results compare favorably with outcomes from previous studies of SBRT. Further studies are needed to better define patient eligibility, study the role of combined modality treatment, optimize treatment parameters, and characterize quality of life after treatment.

Whole-liver radiotherapy for end-stage colorectal cancer patients with massive liver metastases and advanced hepatic dysfunction

BACKGROUND

To investigate whether whole-liver radiotherapy (RT) is beneficial in end-stage colorectal cancer with massive liver metastases and severe hepatic dysfunction.

METHODS

Between June 2004 and July 2008, 10 colorectal cancer patients, who exhibited a replacement of over three quarters of their normal liver by metastatic tumors and were of Child-Pugh class B or C in liver function with progressive disease after undergoing chemotherapy, underwent whole-liver RT. RT was administered using computed tomography-based three-dimensional planning and the median dose was 21 Gy (range, 21-30) in seven fractions. Improvement in liver function tests, defined as a decrease in the levels within 1 month after RT, symptom palliation, toxicity, and overall survival were analyzed retrospectively.

RESULTS

Levels of alkaline phosphatase, total bilirubin, aspartate transaminase, and alanine transaminase improved in 8, 6, 9, and all 10 patients, respectively, and the median reduction rates were 42%, 68%, 50%, and 57%, respectively. Serum carcinoembryonic antigen level decreased after RT in three of four assessable patients. For all patients, pain levels decreased and acute toxicity consisted of nausea/vomiting of grade ≤ 2. Further chemotherapy became possible in four of 10 patients. Mean survival after RT was 80 ± 80 days (range, 20-289); mean survival for four patients who received post-RT chemotherapy was 143 ± 100 days (range, 65-289), versus 38 ± 16 days (range, 20-64) for the six patients who did not receive post-RT chemotherapy (p = 0.127).

CONCLUSIONS

Although limited by small case number, this study demonstrated a possible role of whole-liver RT in improving hepatic dysfunction and delaying mortality from hepatic failure for end-stage colorectal cancer patients with massive liver metastases. Further studies should be followed to confirm these findings.

Efficacy and toxicity related to treatment of hepatocellular carcinoma with 90Y-SIR spheres: radiobiologic considerations

Radioactive (90)Y-selective internal radiation (SIR) sphere therapy is increasingly used for the treatment of nonresectable hepatocellular carcinoma (HCC). However, the maximum delivered dose is limited by severe injury to the nontarget tissue, including liver parenchyma. Our study aimed to implement radiobiologic models for both tumor control probability (TCP) and normal-tissue complication probability (NTCP) to describe more effectively local response and the liver toxicity rate, respectively.

METHODS

Patients with documented HCC, adequate bone marrow parameters, and regular hepatic and pulmonary function were eligible for the study. Patients who had pulmonary shunt greater than 20% of (99m)Tc-labeled macroaggregated albumin or any uncorrectable delivery to the gastrointestinal tract, reverse blood flow out of the liver, or complete portal vein thrombosis were excluded. Patients received a planned activity of the (90)Y-SIR spheres, determined using the empiric body surface area method. The dose distribution was determined using posttreatment (3-dimensional) activity distribution and Monte Carlo dose voxel kernel calculations, and the mean doses to healthy liver and tumor were calculated for each patient. Response was defined according to Response Evaluation Criteria in Solid Tumors (RECIST) and recommendations of the European Association for the Study of the Liver (EASL). Criteria were used to assess possible liver toxicities. The parameters of TCP and NTCP models were established by direct maximization of the likelihood.

RESULTS

Seventy-three patients were treated. With an average dose of 110 Gy to the tumor, complete or partial response was observed in 74% and 55% of patients according to the EASL guideline and RECIST, respectively, and the predicted TCPs were 73% and 55%, respectively. With a median liver dose of 36 Gy (range, 6-78 Gy), the >or=grade 2 (G2), >or=grade 3 (G3), and >or=grade 4 (G4) liver toxicities were observed in 32% (23/73), 21% (15/73), and 11% (8/73) of patients, respectively. The parameters describing the >or=G2 liver toxicity data using the NTCP model were a tolerance dose of the whole organ leading to a 50% complication probability of 52 Gy (95% confidence interval, 44-61 Gy) and a slope of NTCP versus dose of 0.28 (95% confidence interval, 0.18-0.60), assuming n = 1.

CONCLUSION

The radiobiologic approach, based on patient-specific dosimetry, could improve the (90)Y-microsphere therapeutic approach of HCC, maintaining an acceptable liver toxicity.

Emerging role of radiotherapy in the management of liver metastases

Improvements with systemic therapy in controlling occult metastatic disease in patients with colorectal cancer and other solid malignancies have raised renewed interest in local therapies that can treat isolated or "oligo" sites of metastatic disease within the liver. Radiotherapy (RT) is a treatment option that can be offered to patients unsuitable for surgery or other ablative therapies. Technological advances in RT planning and delivery have made it possible to administer high doses conformally around focal liver metastases effectively. Methods to facilitate safe delivery of high-dose RT include conformal RT planning, stereotactic body RT, breathing motion management, and image-guided RT. The clinical experience in conformal RT and stereotactic body RT for liver metastases is emerging, with phase I and II trials demonstrating excellent local control and occasional long-term survivors. With appropriate patient selection and sparing of the uninvolved liver, serious toxicity can be avoided. Out-of-field recurrences are common, providing rationale for combining systemic or regional therapies with RT for these patients. Finally, randomized trials of RT for liver metastases are needed to better define the benefits of RT for these patients.

Effects of phenol, glycerin and acetic acid on the liver of guinea pigs

PURPOSE

To investigate the histolytic action of a solution composed of phenol, glycerin and acetic acid for irresectable hepatic metastasis.

METHODS

Thirty-two (n=32) guinea pigs were randomly distributed into two groups of 16 animals. The animals in group 1 (experimental) and group 2 (control) were redistributed in two subgroups of eight animals each, according to the day of sacrifice (24 hours and four weeks after injection). All the animals were submitted to median laparotomy, which was followed by the injection of solution E and saline into the livers of subjects in both the experimental and control groups, respectively. The animals were evaluated for biochemical and anatomopathological (liver) alterations after 24 hours and four weeks of the experiment.

RESULTS

It was observed that solution E produced necrosis limited to the injected area and that hepatic tissue recovery occurred after four weeks with the formation of a small necrosis area. No biochemical parameters were altered either in the experimental or in the control group.

CONCLUSION

In view of the obtained results, the possibility of using the proposed solution can be considered in cases of irresectable metastasis.

Natural history of hepatocellular carcinoma and prognosis in relation to treatment. Study of 850 patients

A total of 850 patients with hepatocellular carcinoma seen during the last 8 years were analyzed retrospectively for survival in relation to treatment and disease stage. A new staging scheme based on tumor size, ascites, jaundice and serum albumin was used. Clearly, the prognosis depended on disease stage. The median survival of 229 patients who received no specific treatment was 1.6 months, 0.7 month for Stage III patients, 2.0 months for Stage II, and 8.3 months for Stage I. The median survival of Stage I patients who had hepatic resection (n = 115) was 25.6 months and Stage II patients with resection (n = 42) was 12.2 months. In patients who had a small cancer (less than or equal to 25% of liver area in size) the median survival was 29.0 months. Survival of the surgically treated patients, which represented a highly selected group, was better than that of medically treated patients of a comparable stage. Median survival of Stage I medically treated patients (n = 124) was 9.4 months, for Stage II (n = 290) 3.5 months, and for Stage III (n = 50) 1.6 months. Medical treatment prolonged survival in Stage II and III patients, but not in Stage I. Transcatheter arterial embolization gave a better survival compared with chemotherapy, whether intra-arterial bolus administration of mitomycin C, systemic mitomycin C, or oral/rectal tegafur, in Stage II. Among various chemotherapeutic modalities, intra-arterial bolus injection was superior to systemic chemotherapy in survival in Stage II. In Stage III, chemotherapy improved survival as compared with no specific treatment. The major causes of death were hepatic failure and gastrointestinal bleeding, probably due to the coexistent advanced cirrhosis. These results in survival are much improved over the past reports, and the differences are probably a result of earlier diagnosis and frequent hepatic resections.