Incidence and predictors of chest wall toxicity after high-dose radiation therapy in 15 fractions

External Beam Radiation Therapy for Primary Liver Cancers: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations for the indications and technique-dose of external beam radiation therapy (EBRT) in hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC).

METHODS

The American Society for Radiation Oncology convened a task force to address 5 key questions focused on the indications, techniques, and outcomes of EBRT in HCC and IHC. This guideline is intended to cover the definitive, consolidative, salvage, preoperative (including bridge to transplant), and adjuvant settings as well as palliative EBRT for symptomatic primary lesions. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Strong recommendations are made for using EBRT as a potential first-line treatment in patients with liver-confined HCC who are not candidates for curative therapy, as consolidative therapy after incomplete response to liver-directed therapies, and as a salvage option for local recurrences. The guideline conditionally recommends EBRT for patients with liver-confined multifocal or unresectable HCC or those with macrovascular invasion, sequenced with systemic or catheter-based therapies. Palliative EBRT is conditionally recommended for symptomatic primary HCC and/or macrovascular tumor thrombi. EBRT is conditionally recommended as a bridge to transplant or before surgery in carefully selected patients. For patients with unresectable IHC, consolidative EBRT with or without chemotherapy should be considered, typically after systemic therapy. Adjuvant EBRT is conditionally recommended for resected IHC with high-risk features. Selection of dose-fractionation regimen and technique should be based on disease extent, disease location, underlying liver function, and available technologies.

CONCLUSIONS

The task force has proposed recommendations to inform best clinical practices on the use of EBRT for HCC and IHC with strong emphasis on multidisciplinary care. Future studies should focus on further defining the role of EBRT in the context of liver-directed and systemic therapies and refining optimal regimens and techniques.

Hypofractionated Volumetric-Modulated Arc Radiotherapy for Patients With Non-Small-Cell Lung Cancer Not Suitable for Surgery or Conventional Chemoradiotherapy or SBRT

Background

Hypofractionated radiotherapy (HypoRT) has been used to pursue an alternative treatment regimen for patients with non-small-cell lung cancer (NSCLC) who are not eligible for stereotactic ablative radiotherapy (SABR), surgery or concurrent chemoradiotherapy (CCRT) and has shown good local control and safety. We analyzed the feasibility of using volumetric-modulated arc radiotherapy (VMAT) with the simultaneous integrated boost (SIB) technique to achieve high local control with few treatment-related toxicities.

Patients and Methods

A total of 55 patients with stage I-IV NSCLC who were not candidates for SABR, surgery or CCRT were included in the present study. All patients received a prescribed dose of 60 to 66 Gy in 15 fractions. Local progression-free survival (LPFS), PFS, overall survival (OS), and toxicities were retrospectively analyzed.

Results

Thirty-three patients (60.0%) had stage IV or recurrent disease in this study. The median follow-up time was 8 months (interquartile range: 5.0-16.3 months). The 1-year and 2-year OS rates were 84.3% and 69.9%, and the 1-year and 2-year LPFS rates were 91.0% and 63.0%. The median OS (mOS) and median LPFS (mLPFS) were not reached, and median PFS (mPFS) was 15 months. Twenty-eight (51.9%) patients had disease progression at the time of analysis. Of these, 7 (13.0%), 7 (13.0%) and 21 (38.9%) had local recurrence, locoregional failure and distant metastasis, respectively. All cases of local recurrence were found within the SIB region. Four patients had grade 2-3 pneumonitis, and 8 patients had grade 2-3 esophagitis. Patients with grade 2-3 esophagitis had significantly higher maximum dose and dose to 5 cm³ volume to esophagus than those with grade 0-1 esophagitis. No grade 4 or higher toxicity was observed.

Conclusion

The 60 to 66 Gy in 15 fractions RT regimen provides favorable local control and survival with well-tolerated toxicities. Hypofractionated VMAT+SIB is an alternative treatment option for patients with NSCLC who cannot tolerate standard definitive therapy.

Proton therapy for hepatocellular carcinoma: Current knowledges and future perspectives

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy (RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy (PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.

Chest wall toxicity after hypofractionated proton beam therapy for liver malignancies

PURPOSE

Normal liver-sparing with proton beam therapy (PBT) allows for dose escalation in the treatment of liver malignancies, but it may result in high doses to the chest wall (CW). CW toxicity (CWT) data after PBT for liver malignancies are limited, with most published reports describing toxicity after a combination of hypofractionated proton and photon radiation therapy. We examined the incidence and associated factors for CWT after hypofractionated PBT for liver malignancies.

METHODS AND MATERIALS

We retrospectively reviewed the charts of 37 consecutive patients with liver malignancies (30 hepatocellular carcinoma, 6 intrahepatic cholangiocarcinoma, and 1 metastasis) treated with hypofractionated PBT. CWT was scored using Common Terminology Criteria for Adverse Events, version 4. Receiver-operating characteristic curves were used to identify patient and dosimetric factors associated with CWT and to determine optimal dose-volume histogram parameters/cutoffs. Cox regression univariate analysis was used to associate factors to time-dependent onset of CWT.

RESULTS

Thirty-nine liver lesions were treated with a median dose of 60 GyE (range, 35-67.5) in 15 fractions (range, 13-20). Median follow-up was 11 months (range, 2-44). Grade ≥2 and 3 CW pain occurred in 7 (19%) and 4 (11%) patients, respectively. Median time to onset of pain was 6 months (range, 1-14). No patients had radiographic rib fracture. On univariate analysis, CW equivalent 2 Gy dose with an α/β = 3 Gy (EQD2_α/β=3), V57 >20 cm³ (hazard ratio [HR], 2.7; P = .004), V63 >17 cm³ (HR, 2.7; P = .003), and V78 >8 cm³ (HR, 2.6; P = .003) had the strongest association with grade ≥2 CW pain, as did tumor dose of >75 Gy EQD2_α/β=10 (HR, 8.7; P = .03). No other patient factors were associated with CWT.

CONCLUSIONS

CWT after hypofractionated PBT for liver malignancies is clinically relevant. For a 15-fraction regimen, V47 >20 cm³, V50 >17 cm³, and V58 >8 cm³ were associated with higher rates of CWT. Further investigation of PBT techniques to reduce CW dose are warranted.

Proton beam therapy for hepatocellular carcinoma

INTRODUCTION

Radiation therapy is an effective treatment option for hepatocellular carcinoma (HCC) patients. However, radiotherapy for HCC still has limited recognition as a standard treatment option in international consensus guidelines due to a paucity of randomized controlled trials and the risk of hepatotoxicity, which is primarily mediated by baseline liver function and dose delivered to non-tumor liver cells. Proton beam therapy (PBT) may offer advantages over photon-based radiation treatments through its dosimetric characteristic of sparing more liver volume at low to moderate doses. PBT has the potential to reduce radiation-related hepatotoxicity and allow for tumor dose escalation. Areas covered: This article reviews the clinical rationale for using PBT for HCC patients and clinical outcome and toxicity data from retrospective and prospective studies. PBT-specific technical challenges for these tumors and appropriate selection of patients to be treated with PBT are discussed. Expert commentary: Local control, overall survival, and toxicity results are promising for liver PBT. Future studies, including ongoing randomized cooperative group trials, will aim to determine the incremental benefit of PBT over photons and which patients are most suitable for PBT.

Outcomes and toxicity following high-dose radiation therapy in 15 fractions for non-small cell lung cancer

PURPOSE

Accelerated hypofractionated radiation therapy (AHRT) is increasingly used for select lung cancer patients. We evaluated clinical outcomes and predictors of pulmonary/esophageal toxicity in patients treated with ≥52.5 Gy in 15 fractions.

METHODS AND MATERIALS

We evaluated 229 patients treated with radiation therapy doses ≥52.5 Gy in 15 fractions for non-small cell lung cancer from January 2009 through January 2016. Toxicity was scored using Common Terminology Criteria for Adverse Events, v4.0. Univariate and multivariate logistic regression was used to identify predictors of toxicity. Overall survival, progression-free survival, and local control were estimated using the Kaplan-Meier method. Predictors of clinical outcome were modeled using Cox proportional hazards regression.

RESULTS

Median follow-up was 7 months. Forty-two patients (19%) developed grade ≥2 pneumonitis, and 9 (4%) developed grade ≥3 esophagitis. In multivariate analysis, age >75 years (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.24-5.25; P = .01) and percentage of lung volume receiving doses of >10 Gy higher than 32% were associated with grade ≥2 pneumonitis (OR, 2.79; 95% CI, 1.39-5.79; P = .005). On univariate analysis, esophagus mean dose ≥17 Gy (OR, 10.14; 95% CI, 1.82-189.8; P = .006), gross tumor volume size ≥71 cm³ (P = .002), and planning target volume size ≥409 cm³ (P = .02) were associated with development of grade ≥3 esophagitis. In patients with stage II/III disease (n = 73), median local control was not reached, median overall survival was 14 months, and median progression-free survival was 6 months.

CONCLUSIONS

AHRT in 15 fractions can be safe and effective. Consideration for using AHRT with immunotherapy and sequential chemotherapy for improved out-of-radiation field and distant control is warranted.