A validated proton beam therapy patch-field protocol for effective treatment of large hepatocellular carcinoma

The Japanese nationwide cohort data of proton beam therapy for liver oligometastasis in esophagogastric cancer patients

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology in Japan in May 2016. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis of esophagogastric cancers. Cases in which PBT was performed at all PBT facilities in Japan between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: controlled primary cancer, liver recurrence without extrahepatic tumors and no more than three liver lesions. Twenty-two males and two females with a median age of 69 (range, 52-80) years and 35 lesions were included. This study included 6 patients with esophageal and 18 patients with gastric cancer. The median lesion size, fraction size and biological effective dose (BED)10 were 32 (7-104) mm, 3.8 gray (relative biological effect)/fractions (Gy (RBE)/fr) (2-8 Gy (RBE)/fr) and 96.9 (88.8-115.2) Gy, respectively. The median follow-up period was 18 (4-47) months. The 1-, 2- and 3-year overall survival (OS) rates were 75, 51.8 and 45.3%, respectively, and the median OS was 25.3 months. The 1-, 2- and 3-year cumulative local recurrence (LR) rates were 3, 6 and 6%, respectively. Patients' age (P < 0.01), performance status (P = 0.017) and tumor size (P = 0.024) were significant OS-related factors. No Grade 3 or higher adverse events (AEs) were observed. Owing to the low incidence of AEs and the low LR cumulative incidence, PBT is a feasible option for liver oligometastasis of esophagogastric cancers.

Effectiveness of proton beam therapy for liver oligometastatic recurrence in patients with postoperative esophagus cancer

There are several reports of hepatic resection for postoperative hepatic metastatic recurrence of esophageal cancer. However, it is unclear whether surgery is the best local treatment for liver metastases. Thus, this study aimed to retrospectively analyze proton beam therapy (PBT) for postoperative liver metastatic recurrence of esophageal cancer without extrahepatic lesions and examine outcomes and adverse events. This single-center historical cohort study selected patients who underwent PBT at our proton therapy center between 2012 and 2018. The patients were selected based on the following criteria: primary esophagus carcinoma was resection and metachronous liver oligometastasis recurrence without extrahepatic tumors and no more than three liver metastases. This study included seven males with a median age of 66 (range, 58-78) years, and 15 lesions were included in the study. The median tumor size was 22.6 (7-55.3) mm. The most frequent dose was 72.6 Gy relative biological effect (RBE)/22 fractions (fr) for four lesions and 64 Gy (RBE)/8 fr for four lesions. The median survival time was 35.5 (13.2-119.4) months. The 1-, 2- and 3-year overall survival (OS) rates were 100%, 57.1% and 42.9%, respectively. The median progression-free survival (PFS) time was 8.7 (1.2-44.1) months. The 1-, 2- and 3-year PFS rates were 28.6%. The 1-, 2- and 3-year local control (LC) rates were 100%. No grade ≥4 radiation-induced adverse events (AEs) were observed. We conclude that PBT can be considered an alternative to hepatic resection for recurrent liver metastases postoperative esophageal cancer.

Analysis of person-hours required for proton beam therapy for pediatric tumors

Proton beam therapy (PBT) is effective for pediatric tumors, but patients may require sedation and other preparations, which extend the treatment time. Pediatric patients were classified into sedation and non-sedation cases. Adult patients were classified into three groups based on irradiation from two directions without or with respiratory synchronization and patch irradiation. Treatment person-hours were calculated as follows: (time from entering to leaving the treatment room) × (number of required personnel). A detailed analysis showed that the person-hours required for the treatment of pediatric patients are about 1.4-3.5 times greater than those required for adult patients. With the inclusion of additional time for the preparation of pediatric patients, PBT for pediatric cases is two to four times more labor-intensive than for typical adult cases.

The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors

PURPOSE

To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver.

METHODS AND MATERIALS

Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience.

RESULTS

The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered.

CONCLUSIONS

ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.

Proton Therapy in the Management of Hepatocellular Carcinoma

Proton radiation therapy plays a central role in the treatment of hepatocellular carcinoma (HCC). Because of the near-zero exit dose and improved sparing of normal liver parenchyma, protons are being used even in challenging scenarios, including larger or multifocal liver tumors, and those associated with vascular tumor thrombus. There is a mounting level of evidence that suggests that protons are superior to photons in terms of survival and toxicity outcomes, specifically the progression to liver failure. A randomized controlled trial comparing protons to photons is currently underway to verify this hypothesis.

One Cycle of Concurrent Chemotherapy vs. Two Cycles of Concurrent Chemotherapy With Radiation Therapy in Patients With Limited-Stage Small Cell Lung Cancer

Background

The optimal number of concurrent chemotherapy cycles during thoracic radiotherapy (RT) in patients with limited stage-small cell lung cancer (LS-SCLC) is not well defined. The purpose of this study was to evaluate the impact of the number of concurrent chemotherapy cycles on prognosis of LS-SCLC.

Material and Methods

Patients with LS-SCLC treated with concurrent chemo-radiotherapy from May 2008 to December 2020 in our hospital were retrospectively analyzed. The prescribed radiation dose was 60Gy administrated with conventional RT in 30 fractions within 6 weeks. The prognostic role of cycle number of chemotherapy administrated concurrently with RT were analyzed. All patients were followed up at one month after the treatment, then once every three months until two years after the treatment, and every six months thereafter. Propensity score matching (PSM) was performed to reduce confounding factors. The primary endpoint was overall survival (OS). Survival analysis was performed with Kaplan-Meier and multivariate analysis was performed with Cox regression model.

Results

Among the 370 patients who received radical radiotherapy, 206 patients received concurrent chemo-radiotherapy and were included for the analysis. Multivariate analysis showed that stage and PCI were independent prognostic factors for OS. The median OS in patients who received one cycle and two cycles of chemotherapy concurrently with RT were 32.9 months and 31.6 months, respectively (P = 0.241). And the median PFS were 20.6 months and 18.4 months, respectively (P = 0.764). After PSM, no statistical differences in OS and PFS were observed between patients who received one cycle and those who received two cycles of concurrent chemotherapy.

Conclusion

Two cycles of concurrent chemotherapy during RT were not necessarily superior compared to one cycle in LS-SCLC. The optimal cycle number of concurrent chemotherapy during RT needs to be further studied.

Transitions of Liver and Biliary Enzymes during Proton Beam Therapy for Hepatocellular Carcinoma

Proton beam therapy (PBT) is a curative treatment for hepatocellular carcinoma (HCC), because it can preserve liver function due to dose targeting via the Bragg peak. However, the degree of direct liver damage by PBT is unclear. In this study, we retrospectively analyzed liver/biliary enzymes and total bilirubin (T-Bil) as markers of direct liver damage during and early after PBT in 300 patients. The levels of these enzymes and bilirubin were almost stable throughout the treatment period. In patients with normal pretreatment levels, aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), and T-Bil were abnormally elevated in only 2 (1.2%), 1 (0.4%), 0, 2 (1.2%), and 8 (3.5%) patients, respectively, and in 8 of these 13 patients (61.5%) the elevations were temporary. In patients with abnormal pretreatment levels, the levels tended to decrease during PBT. GGT and T-Bil were elevated by 1.62 and 1.57 times in patients who received 66 Gy (RBE) in 10 fractions and 74 Gy (RBE) in 37 fractions, respectively, but again these changes were temporary. These results suggest that direct damage to normal liver caused by PBT is minimal, even if a patient has abnormal pretreatment enzyme levels.

Phase I Radiation Dose-Escalation Study to Investigate the Dose-Limiting Toxicity of Concurrent Intra-Arterial Chemotherapy for Unresectable Hepatocellular Carcinoma

Concurrent intra-arterial chemotherapy and radiotherapy (iA-CCRT) can increase the response rate in hepatocellular carcinoma (HCC), but may cause a higher toxicity. We conducted this Phase I study to investigate the dose-limiting toxicity of iA-CCRT for HCC. In total, 52.5 Gy in 25 fractions was prescribed as planning target volume (PTV) 1 at dose level 1. The dose escalation was 0.2 Gy per fraction and up to 2.5 Gy, with 62.5 Gy at level 3. Concurrent intra-arterial 5-fluorouracil was administered during the first and fifth weeks of radiotherapy (RT). Toxicities were graded using the Common Toxicity Criteria for Adverse Events, version 4.0. Results: Seventeen patients with HCC were analyzed: four at dose level 1, 6 at level 2, and 7 at level 3. The mean irradiated dose administered to the uninvolved liver at each dose level was 21.3, 21.6, and 18.2 Gy, respectively. There was no grade ≥3 gastrointestinal toxicity; two patients experienced grade 3 hyperbilirubinemia. All patients had Child-Pugh class A disease, but 3 patients developed class B disease after iA-CCRT. During a median follow-up of 13 months, the median progression-free survival (PFS) and overall survival (OS) were 10 and 22 months, respectively. Patients treated at dose level 3 showed improved PFS and OS. Conclusions: Radiation dose escalation of iA-CCRT did not cause any significant toxicities in patients with advanced HCC. Further large-scale studies with long-term follow-up are needed to determine the efficacy and feasibility of higher doses of iA-CCRT.

Proton beam therapy for hepatocellular carcinoma associated with inferior vena cava tumor thrombus

PURPOSE

Hepatocellular carcinoma (HCC) with inferior vena cava tumor thrombus (IVCTT) is rare and regarded as an advanced disease stage with poor prognosis. Treatment effect data regarding HCC with IVCTT is scarce and clear evidence has not been established. This study, therefore, aims to examine the safety and effectiveness of proton beam therapy (PBT) for HCC patients with IVCTT.

METHODS

From January 2005 to December 2014, a total of 21 HCC patients with IVCTT were analyzed. The total irradiation doses ranged from 50 to 74 (median 72.6) gray relative biological effectiveness.

RESULTS

The follow-up period was 4-120 (median 21) months. Regarding acute toxicities, dermatitis of grade 1-2 was observed in all patients, while no grade 3 or higher late toxicity events were encountered. The overall survival (OS) rates for all patients were 62%, 33%, and 19% at 1, 2, and 3 years, respectively. No local recurrences for the treated lesions, including IVCTT, were observed. According to univariate analysis, IVCTT extension type was not associated with prognosis, but only tumor number significantly affected the OS rate (p = 0.003). For 10 single lesion patients, the longest survival time was 120 months with OS rates of 82%, 64%, and 36% at 1, 2, and 3 years, respectively.

CONCLUSION

PBT is safe and effective for HCC patients with IVCTT, especially those with single lesion status. PBT is an important treatment option for HCC patients with IVCTT.

[Influence and Countermeasure of Respiratory Motion on Matchline Profile of Field Matching Technique in Passive Scattering Proton Therapy for Esophageal Cancer]

This study aimed to evaluate the influence of change in respiratory motion on matchline (ML) and reduction of the effect by increasing ML levels of field matching technique in passive scattering proton therapy for esophageal cancer. To evaluate the influence of respiratory motion in terms of stability, we measured relative dose around ML using a respiratory motion phantom. The relative error was -0.5% when the respiratory motion phantom worked stable, whereas there was obvious change that the relative error was -25.5% when the difference of amplitude between upper field and lower field was one side 3 mm on each cranially and caudally direction. In clinical case of the seven esophageal cancer patients simulated by the treatment planning system, assuming the difference of amplitude was 3 mm, the relative error of maximum (minimum) dose in clinical target volume around ML against the original treatment plan were 5.8±1.2% (-6.0±2.7%), 3.3±0.9% (-3.8±1.0%), and 2.4±0.5% (2.6±0.8%) on average (±SD) when ML levels were 2, 4, and 6, respectively. Increasing ML levels can reduce the influence of respiratory motion.