Effect of CyberKnife stereotactic body radiation therapy for hepatocellular carcinoma on hepatic toxicity

Dosimetric comparison of proton therapy and CyberKnife in stereotactic body radiation therapy for liver cancers

Stereotactic body radiation therapy (SBRT) has been increasingly used for the ablation of liver tumours. CyberKnife and proton beam therapy (PBT) are two advanced treatment technologies suitable to deliver SBRT with high dose conformity and steep dose gradients. However, there is very limited data comparing the dosimetric characteristics of CyberKnife to PBT for liver SBRT. PBT and CyberKnife plans were retrospectively generated using 4DCT datasets of ten patients who were previously treated for hepatocellular carcinoma (HCC, N = 5) and liver metastasis (N = 5). Dose volume histogram data was assessed and compared against selected criteria; given a dose prescription of 54 Gy in 3 fractions for liver metastases and 45 Gy in 3 fractions for HCC, with previously published consensus-based normal tissue dose constraints. Comparison of evaluation parameters showed a statistically significant difference for target volume coverage and liver, lungs and spinal cord (p < 0.05) dose, while chest wall and skin did not indicate a significant difference between the two modalities. A number of optimal normal tissue constraints was violated by both the CyberKnife and proton plans for the same patients due to proximity of tumour to chest wall. PBT resulted in greater organ sparing, the extent of which was mainly dependent on tumour location. Tumours located on the liver periphery experienced the largest increase in organ sparing. Organ sparing for CyberKnife was comparable with PBT for small target volumes.

Albumin-bilirubin score is a useful predictor of worsening liver reserve after stereotactic body radiation therapy in elderly Japanese patients with hepatocellular carcinoma

The prognosis of patients with hepatocellular carcinoma (HCC) is closely related to their liver reserves. The Child-Pugh (CP) score has traditionally been used to evaluate this reserve, with CP Grade B (CP score ≥ 7) associated with a higher risk of radiation-induced liver disease after stereotactic body radiation therapy (SBRT). However, the CP score has limitations, as it does not accurately assess liver reserve capacity. The albumin-bilirubin (ALBI) score has been introduced as a meticulous indicator of liver reserve for the treatment of HCC. We retrospectively evaluated the role of the ALBI score in estimating the worsening liver reserve in 42 patients with HCC treated with SBRT using CyberKnife between 2015 and 2023. The median biologically effective dose (α/β = 10 Gy) was 100 Gy. For a median follow-up duration of 17.4 months, the 1-year overall survival (OS), local control (LC) and progression-free survival (PFS) rates were 100, 98 and 62%, respectively. Worsening liver reserve was defined as an increase in the modified ALBI grade or CP score within 1 year after SBRT. Univariate and multivariate analyses showed that the baseline ALBI score (≥-2.7 vs <-2.7) was the only significantly different predictor of worsening liver reserve. The OS and LC rates after SBRT for HCC were satisfactory. However, the PFS was poor, and recurrent HCC will require additional treatment. It is clinically important to predict the liver reserve capacity after SBRT, and the baseline ALBI score is a useful predictor.

Radiotherapy plus anti-PD1 versus radiotherapy for hepatic toxicity in patients with hepatocellular carcinoma

PURPOSE

In this study, we aimed to compare the radiation-induced hepatic toxicity (RIHT) outcomes of radiotherapy (RT) plus antibodies against programmed cell death protein 1 (anti-PD1) versus RT alone in patients with hepatocellular carcinoma (HCC), evaluate prognostic factors of non-classic radiation-induced liver disease (ncRILD), and establish a nomogram for predicting the probability of ncRILD.

PATIENTS AND METHODS

Patients with unresectable HCC treated with RT and anti-PD1 (RT + PD1, n = 30) or RT alone (n = 66) were enrolled retrospectively. Patients (n = 30) in each group were placed in a matched cohort using propensity score matching (PSM). Treatment-related hepatotoxicity was evaluated and analyzed before and after PSM. The prognostic factors affecting ncRILD were identified by univariable logistic analysis and Spearman's rank test in the matched cohort to generate a nomogram.

RESULTS

There were no differences in RIHT except for increased aspartate aminotransferase (AST) ≥ grade 1 and increased total bilirubin ≥ grade 1 between the two groups before PSM. After PSM, AST ≥ grade 1 occurred more frequently in the RT + PD1 group (p = 0.020), and there were no significant differences in other hepatotoxicity metrics between the two groups. In the matched cohort, V25, tumor number, age, and prothrombin time (PT) were the optimal prognostic factors for ncRILD modeling. A nomogram revealed a good predictive performance (area under the curve = 0.82).

CONCLUSIONS

The incidence of RIHT in patients with HCC treated with RT + PD1 was acceptable and similar to that of RT treatment. The nomogram based on V25, tumor number, age, and PT robustly predicted the probability of ncRILD.

[Image-guided, minimally invasive surgery and other local therapeutic procedures for primary liver tumors]

BACKGROUND

The incidence of primary liver tumors is rising. Modern minimally invasive, image-guided procedures offer a potentially curative therapy option.

OBJECTIVE

The aim of this study was to evaluate the multitude of image-guided minimally invasive procedures concerning their evidence-based effect on local tumor control and overall survival.

MATERIAL AND METHODS

A systematic search of MEDLINE focused on hepatocellular cancer, minimally invasive treatment, local ablative therapy, therapeutic stratification and comparative studies was performed.

RESULTS

The level of evidence varied greatly depending on the procedure used. The highest quality evidence including prospective randomized studies was found for radiofrequency ablation (RFA) of hepatocellular cancer. The RFA is superior with respect to local tumor control and overall survival in comparison to other ablative procedures. Prospective randomized studies comparing surgery and RFA showed diverging and contradictory results. Microwave ablation and robotic stereotactic irradiation showed sufficient potential in retrospective studies in comparison to RFA and surgery in order to confirm the techniques in randomized studies. There is only anecdotal evidence concerning high intensity focused ultrasound (HIFU) and irreversible electroporation. Percutaneous ethanol injection (PEI), cryoablation and laser-induced thermal therapy (LITT) were inferior techniques to RFA in most studies.

CONCLUSION

Minimally invasive resection and local ablative therapies based on structured imaging and image reporting can improve the prognosis of patients with hepatocellular cancer even in patients that exceed the BCLC 0/A stage.

Stereotactic body radiation therapy in primary hepatocellular carcinoma: current status and future directions

Stereotactic body radiation therapy (SBRT) is a form of radiation therapy that has been used in the treatment of primary hepatocellular carcinoma (HCC) over the past decade. To evaluate the clinical efficacy of SBRT in primary HCC, a literature search was conducted to identify original research articles published from January 2000 through January 2018 in PubMed on SBRT in HCC. All relevant studies published from 2004 to 2018 were included. Prospective studies demonstrated 2-year local control (LC) rates ranging from 64-95% and overall survival (OS) rates ranging from 34% (2-year) to 65% (3-year). Retrospective studies demonstrated 2-year LC rates of 44-90% and 2-year OS rates of 24-67%. Reported toxicities in primary HCC patients vary but SBRT appears to be relatively well tolerated. Studies comparing SBRT to radiofrequency ablation (RFA) are few, but they suggest SBRT may be more effective than RFA in specific primary HCC populations. Additionally, SBRT appears to increase the efficacy of both transarterial chemoembolization (TACE) and sorafenib in selected primary HCC populations.

How small is TOO small? New liver constraint is needed- Proton therapy of hepatocellular carcinoma patients with small normal liver

PURPOSE

This study evaluated the outcomes of hepatocellular carcinoma (HCC) patients with small normal liver volume (NLV) treated with proton beam therapy (PBT) and introduced estimated standard liver volume (eSLV) as a new constraint.

MATERIALS AND METHODS

HCC patients with NLV < 800 cm3 and no distant metastasis who received treatment in our proton center were included. The doses of PBT were mainly 72.6 Gray equivalents (GyE) in 22 fractions and 66 GyE in 10 fractions according to tumor locations. The Urata equation was used to calculate eSLV.

RESULTS

Twenty-two patients were treated between November 2015 and December 2016. The 1-year progression-free and overall survival rates were 40.4% and 81.8%, respectively. The 1-year in-field failure-free rate was 95.5%. NLV ranged from 483.9 to 795.8 cm3 (median = 673.8 cm3), eSLV ranged from 889.3 to 1290.0 cm3 (median = 1104.5 cm3), and the resulting NLV/eSLV ratio ranged from 44.3 to 81.2% (median = 57.7%). Non-irradiated liver volume (NILV) ranged from 232.9 to 531.6 cm3 (median = 391.2 cm3). The NILV/eSLV ratio ranged from 21.2 to 48.0% (median = 33.3%). NLV in the patients who received <30 GyE (rV30) ranged from 319.1 to 633.3 cm3 (median = 488.2 cm3), and their rV30/eSLV ratio ranged from 30.7 to 58.0%. None of our patients developed liver failure. One patient with initial abnormal liver enzyme levels developed non-classic radiation-induced liver disease (RILD).

CONCLUSION

From the viewpoint of minimal liver toxicity occurring in our patients with NLV < 800 cm3, conventional liver constraints involving the use of absolute volume could not accurately predict the risk of RILD. It is reasonable to start using individualized constraints with eSLV for HCC patients undergoing PBT. According to the study results, an NILV/eSLV ratio of >20% and an rV30/eSLV ratio of >30% are acceptable.

Haptic Feedback for Control and Active Constraints in Contactless Laser Surgery: Concept, Implementation, and Evaluation

Haptics has proven to be highly beneficial in surgical robotics, bringing enhanced safety and precision by complementing the surgeon's visual channel. However, most of the research body in this context is dedicated to applications involving traditional "cold steel" surgical instruments. This paper proposes to bring the benefits of haptics to contactless surgeries, and presents a novel method to achieve this. The specific case of robot-assisted laser microsurgery is investigated. Here, a fictitious force feedback is created through stereoscopic visualization and 3D reconstruction, allowing the surgeon to sense the surgical area haptically while controlling a non-contact surgical laser. This is shown to significantly improve system usability and the accuracy of laser incisions, especially in applications involving several passes of the laser over the same incision line. Validation of the system is performed through two series of experiments involving both naive users and expert surgeons. The obtained results demonstrate that haptics can indeed be introduced in contactless laser surgery, allowing the exploitation of active constraints and guidance techniques that significantly enhance laser control accuracy both in static and dynamic environments. Furthermore, the proposed haptic technology shows good acceptance and high usability, indicating it has great potential to positively impact real surgeries.

Strategic application of radiotherapy for hepatocellular carcinoma

With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT. An essential feature of IGRT is that it allows image guidance therapy through in-room images obtained during radiation delivery. Compared with 3D-conformal RT, distinctions of IMRT are inverse treatment planning process and use of a large number of treatment fields or subfields, which provide high precision and exquisitely conformal dose distribution. These modern RT techniques allow more precise treatment by reducing inter- and intra-fractional errors resulting from daily changes and irradiated dose at surrounding normal tissues. More recently, particle therapy has been actively investigated to improve effectiveness of RT. This review discusses modern RT strategies for HCC, as well as optimal selection of RT in multimodal approach for HCC.