SBRT in unresectable advanced pancreatic cancer: preliminary results of a mono-institutional experience

EUS-guided hydrogel injection to separate pancreatic head carcinoma from duodenum for enhanced radiotherapy: Multi-site feasibility study

Background and study aims The proximity of a pancreas head tumor to the duodenum often limits delivery of an ablative dose of radiation therapy. This study evaluated the feasibility and safety of using an injectable polyethylene glycol (PEG) hydrogel between the head of the pancreas and duodenum. Patients and methods In a multi-site feasibility cohort study of patients with localized pancreatic cancer, PEG hydrogel was injected under endoscopic ultrasound guidance to temporarily position the duodenum away from the pancreas. Procedure characteristics were recorded, including hydrogel volume and space created. Patients were monitored for adverse events (AEs) and radiotherapy toxicity. Results In all six intent-to-treat patients (four with borderline resectable, two with locally advanced disease), the ability to place and visualize PEG hydrogel and create space between the duodenum and the head of the pancreas was successful. There were no procedure-related AEs resulting in radiotherapy delay. There were no device-related AEs and no reports of pancreatitis. Conclusions PEG hydrogel was successfully placed, created space between the duodenum and the head of the pancreas, and was not associated with major toxicity. Enhancing radiotherapy for pancreatic cancer by using PEG hydrogel to create peri-duodenal space could have beneficial implications for treatment and warrants more exploration.

Stereotactic body radiotherapy for pancreatic cancer - A systematic review of prospective data

Purpose

This systematic review aims to comprehensively summarize the current prospective evidence regarding Stereotactic Body Radiotherapy (SBRT) in various clinical contexts for pancreatic cancer including its use as neoadjuvant therapy for borderline resectable pancreatic cancer (BRPC), induction therapy for locally advanced pancreatic cancer (LAPC), salvage therapy for isolated local recurrence (ILR), adjuvant therapy after radical resection, and as a palliative treatment. Special attention is given to the application of magnetic resonance-guided radiotherapy (MRgRT).

Methods

Following PRISMA guidelines, a systematic review of the Medline database via PubMed was conducted focusing on prospective studies published within the past decade. Data were extracted concerning study characteristics, outcome measures, toxicity profiles, SBRT dosage and fractionation regimens, as well as additional systemic therapies.

Results and conclusion

31 studies with in total 1,571 patients were included in this review encompassing 14 studies for LAPC, 9 for neoadjuvant treatment, 2 for adjuvant treatment, 2 for ILR, with an additional 4 studies evaluating MRgRT. In LAPC, SBRT demonstrates encouraging results, characterized by favorable local control rates. Several studies even report conversion to resectable disease with substantial resection rates reaching 39%. The adoption of MRgRT may provide a solution to the challenge to deliver ablative doses while minimizing severe toxicities. In BRPC, select prospective studies combining preoperative ablative-dose SBRT with modern induction systemic therapies have achieved remarkable resection rates of up to 80%. MRgRT also holds potential in this context. Adjuvant SBRT does not appear to confer relevant advantages over chemotherapy. While prospective data for SBRT in ILR and for palliative pain relief are limited, they corroborate positive findings from retrospective studies.

Dose-escalated SBRT for borderline and locally advanced pancreatic cancer. Feasibility, safety and preliminary clinical results of a multicenter study

Background

Pancreatic Stereotactic Body Radiotherapy (SBRT) allows for the administration of a higher biologically effective doses (BED), that would be essential to achieve durable tumor control. Escalating treatment doses need a very accurate tumor positioning and motion control during radiotherapy.The aim of this study to assess the feasibility and safety of a Simultaneous Integrated Boost (SIB) dose-escalated protocol at 45 Gy, 50 Gy and 55 Gy in 5 consecutive daily fractions, in Border Line Resectable Pancreatic Cancer (BRCP) /Locally Advanced Pancreatic Cancer (LAPC) by means of a standard LINAC platform.

Methods

Patients diagnosed of BRPC/LAPC, candidates for neoadjuvant chemotherapy and SBRT, in four university hospitals of the province of Las Palmas (Canary Islands, Spain) were included in this prospective study. Radiotherapy was administered using standard technology (LINACS) with advanced positioning (Lipiodol® and metallic stent used as fiducial markers) and tumor motion control (4D, DBH, Calypso®). There were 3 planned dose-escalated SIB groups, 45 Gy/5f (9 patients) 50 Gy/5f (9 + 9 patients) and 55 Gy/5f (9 patients). The defined primary end points of the study were the safety and feasibility of the proposed treatment protocol. Secondary endpoints included radiological tumor response after SBRT, local control and survival.

Results

From June 2017 to December 2022, sixty-two patients were initially assessed for eligibility in the study in the four participating centers, and 49 were candidates for chemotherapy (CHT). Forty-one were referred to radiotherapy after CHT and 33 finally were treated by escalated-dose SIB, 45 Gy (9 patients) 50 Gy (16 patients), 55 Gy(8 patients). All patients completed the scheduled treatment and no acute or late severe (≥grade3) gastrointestinal toxicity was observed.Local response was analyzed by CT/MRI two months after the end of SBRT. Ten patients (31,25 %) achieved objective response (2/9:45 Gy, 5/15:50 Gy, 3/8:55 Gy). Follow-up was closed as July 2023. Freedom from local progression at 1-2y were 89,3% (95 %CI:83,4-95,2%) and 66 % (95 %CI:54,6-77,4%) respectively. The 1-2y survival rates were 95,7% (95 %CI:91,4-100 % and 48,6% (95 %CI:37,7-59,5%) respectively.

Conclusion

These promising results should be confirmed by further studies with larger sample size and extended follow-up period.

Impact of Short-Course Palliative Radiation Therapy on Pancreatic Cancer-Related Pain: Prospective Phase 2 Nonrandomized PAINPANC Trial

PURPOSE

Clinical evidence is limited regarding palliative radiation therapy for relieving pancreatic cancer-related pain. We prospectively investigated pain response after short-course palliative radiation therapy in patients with moderate-to-severe pancreatic cancer-related pain.

METHODS AND MATERIALS

In this prospective phase 2 single center nonrandomized trial, 30 patients with moderate-to-severe pain (5-10, on a 0-10 scale) of pancreatic cancer refractory to pain medication, were treated with a short-course palliative radiation therapy; 24 Gy in 3 weekly fractions (2015-2018). Primary endpoint was defined as a clinically relevant average decrease of ≥2 points in pain severity, compared with baseline, within 7 weeks after the start of treatment. Secondary endpoint was global quality of life (QoL), with a clinically relevant increase of 5 to 10 points (0-100 scale). Pain severity reduction and QoL were assessed 9 times using the Brief Pain Inventory and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C15-PAL, respectively. Both outcomes were analyzed using joint modeling. In addition, acute toxicity based on clinician reporting and overall survival (OS) were assessed.

RESULTS

Overall, 29 of 30 patients (96.7%) received palliative radiation therapy. At baseline, the median oral morphine equivalent daily dose was 129.5 mg (range, 20.0-540.0 mg), which decreased to 75.0 mg (range, 15.0-360.0 mg) after radiation (P = .021). Pain decreased on average 3.15 points from baseline to 7 weeks (one-sided P = .045). Patients reported a clinically relevant mean pain severity reduction from 5.9 to 3.8 points (P = .011) during the first 3 weeks, which further decreased to 3.2 until week 11, ending at 3.4 (P = .006) in week 21 after the first radiation therapy fraction. Global QoL significantly improved from 50.5 to 60.8 during the follow-up period (P = .001). Grade 3 acute toxicity occurred in 3 patients and no grade 4 to 5 toxicity was observed. Median OS was 11.8 weeks, with a 13.3% 1-year actuarial OS rate.

CONCLUSIONS

Short-course palliative radiation therapy for pancreatic cancer-related pain was associated with rapid, clinically relevant reduction in pain severity, and clinically relevant improvement in global QoL, with mostly mild toxicity.

Stereotactic body radiotherapy in pancreatic adenocarcinoma

BACKGROUND

Stereotactic body radiotherapy (SBRT) in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding tissue. This review aimed at the SBRT application in the treatment of pancreatic cancer.

DATA SOURCES

We retrieved articles published in MEDLINE/PubMed from January 2017 to December 2022. Keywords used in the search included: "pancreatic adenocarcinoma" OR "pancreatic cancer" AND "stereotactic ablative radiotherapy (SABR)" OR "stereotactic body radiotherapy (SBRT)" OR "chemoradiotherapy (CRT)". English language articles with information on technical characteristics, doses and fractionation, indications, recurrence patterns, local control and toxicities of SBRT in pancreatic tumors were included. All articles were assessed for validity and relevant content.

RESULTS

Optimal doses and fractionation have not yet been defined. However, SBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to CRT. Furthermore, the combination of SBRT with chemotherapy may have additive or synergic effect on pancreatic adenocarcinoma.

CONCLUSIONS

SBRT is an effective modality for patients with pancreatic cancer, supported by clinical practice guidelines as it has demonstrated good tolerance and good disease control. SBRT opens a possibility of improving outcomes for these patients, both in neoadjuvant treatment and with radical intent.

Can STEreotactic Body Radiation Therapy (SBRT) Improve the Prognosis of Unresectable Locally Advanced Pancreatic Cancer? Long-Term Clinical Outcomes, Toxicity and Prognostic Factors on 142 Patients (STEP Study)

AIM

The gold standard of care for pancreatic adenocarcinoma is the integrated treatment of surgery and chemotherapy (ChT), but about 50% of patients present with unresectable disease. Our study evaluated the efficacy in terms of local control, survival and safety of stereotactic body radiation therapy (SBRT) in locally advanced pancreatic cancer (LAPC).

METHODS

A retrospective study (STEP study) analyzed patients with LAPC treated with a dose of 45 Gy in 6 fractions. Local control (LC), distant progression free survival (DPFS), overall survival (OS) and toxicity were analyzed according to the Kaplan-Meier method.

RESULTS

A total of 142 patients were evaluated. Seventy-six patients (53.5%) received induction ChT before SBRT. The median follow-up was 11 months. One-, 2- and 3-year LC rate was 81.9%, 69.1% and 58.5%. Median DPFS was 6.03 months; 1- and 2-year DPFS rate was 19.9% and 4.5%. Median OS was 11.6 months and 1-, 2- and 3-year OS rates were 45.4%, 16.1%, and 9.8%. At univariate analysis, performed by the log-rank test, age < 70 years (p = 0.037), pre-SBRT ChT (p = 0.004) and post-SBRT ChT (p = 0.019) were associated with better OS. No patients experienced G3 toxicity.

CONCLUSION

SBRT represents an effective and safe therapeutic option in the multimodal treatment of patients with LAPC in terms of increased LC. When SBRT was sequentially integrated with ChT, the treatment proved to be promising in terms of OS as well.

Radiotherapy in Pancreatic Cancer: To Whom, When, and How?

The diagnosis rate of pancreatic cancer is steadily increasing. The average age of onset is close to 70 years. In most cases, the disease is diagnosed at an advanced stage. The indications for and techniques of radiotherapy are changing over time. The aim of this thesis is to present the role and possibilities of radiotherapy from the perspective of radiation oncologist. The most common cause of treatment failure in pancreatic cancer remains generalisation. The implementation of new systemic treatment regimens contributes to improved treatment outcomes regardless of the stage of the disease. With improved treatment outcomes in terms of the incidence of distant metastases, the impact of local curability on the length and quality of life of patients increases. Modern radiotherapy offers the opportunity to achieve high local cure rates. Postoperative radiotherapy in combination with chemotherapy seems justified in the group of postoperative pancreatic cancer patients with pT3 and pN+ features. In the group of patients with borderline resectable pancreatic cancer, the impact of radiotherapy in combination with the latest chemotherapy regimens is difficult to define clearly. In the setting of a diagnosis of advanced pancreatic cancer, radiotherapy, especially stereotactic radiotherapy, in combination with chemotherapy, contributes to improved local curability and allows to achieve a significantly reduced level of pain.

Comparative Effectiveness of Chemotherapy Alone Versus Radiotherapy-Based Regimens in Locally Advanced Pancreatic Cancer: A Real-World Multicenter Analysis (PAULA-1)

Different options for locally advanced pancreatic cancer (LAPC) are available based on international guidelines: chemotherapy (CHT), chemoradiation (CRT), and stereotactic body radiotherapy (SBRT). However, the role of radiotherapy is debated in LAPC. We retrospectively compared CHT, CRT, and SBRT ± CHT in a real-world setting in terms of overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS). LAPC patients from a multicentric retrospective database were included (2005-2018). Survival curves were calculated using the Kaplan-Meier method. Multivariable Cox analysis was performed to identify predictors of LC, OS, and DMFS. Of the 419 patients included, 71.1% were treated with CRT, 15.5% with CHT, and 13.4% with SBRT. Multivariable analysis showed higher LC rates for CRT (HR: 0.56, _95%CI 0.34-0.92, p = 0.022) or SBRT (HR: 0.27, _95%CI 0.13-0.54, p < 0.001), compared to CHT. CRT (HR: 0.44, _95%CI 0.28-0.70, p < 0.001) and SBRT (HR: 0.40, _95%CI 0.22-0.74, p = 0.003) were predictors of prolonged OS with respect to CHT. No significant differences were recorded in terms of DMFS. In selected patients, the addition of radiotherapy to CHT is still an option to be considered. In patients referred for radiotherapy, CRT can be replaced by SBRT considering its duration, higher LC rate, and OS rate, which are at least comparable to that of CRT.

Efficacy of stereotactic body radiation therapy for locoregional recurrent pancreatic cancer after radical resection

Objective

This study aimed to analyze the efficacy and toxicity of stereotactic body radiotherapy (SBRT) for locoregional recurrent pancreatic cancer after radical resection.

Methods

Patients with locoregional recurrent pancreatic cancer after surgery treated with SBRT in our institution were retrospectively investigated from January 2010 to January 2020. Absolute neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) recorded at pretreatment were analyzed. Endpoints included overall survival (OS), progression-free survival (PFS) and cumulative incidences of local failure (LF) and metastatic failure (MF).

Results

A total of 22 patients received SBRT with a median prescribed dose of 40 Gy (range of 30-50 Gy)/4 to 7 fractions. The median OS of all patients was 13.6 months (95% CI, 9.6-17.5 months). 0-1 performance status (HR 12.10, 95% CI 2.04-71.81, P=0.006) and ≤2.1 pre-SBRT NLR (HR 4.05, 95% CI 1.21-13.59, P=0.023) were significant predictors of higher OS on multivariable analysis. The median progression-free survival (PFS) of the cohort was 7.5 months (95% CI, 6.5-8.5 months). The median time to LF and MF were 15.6 months and 6.4 months, respectively. The rate of MF as a first event was higher than that of first event LF. Pain relief was observed in all patients (100%) 6 weeks after SBRT. In terms of acute toxicity, grade 1 including fatigue (6, 27.3%), anorexia (6, 27.3%), nausea (4, 18.2%) and leukopenia (4, 18.2%) was often observed. No acute toxicity of grade 4 or 5 was observed. In terms of late toxicity, no treatment-related toxicity was found during follow-up.

Conclusion

This study showed that SBRT can significantly reduce pain, effectively control local tumor progression, and have acceptable toxicity for patients with locoregional recurrence after radical resection of primary pancreatic cancer. Good performance status and lower pre-SBRT NLR were associated with improved overall survival.

Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer Using Optical Surface Management System - AlignRT as an Optical Body Surface Motion Management in Deep Breath Hold Patients: Results from a Single-Arm Retrospective Study

Purpose

To assess the efficacy and safety of stereotactic body radiotherapy for patients with unresectable, locally advanced pancreatic cancer using Optical Surface Management System - AlignRT (OSMS-AlignRT) as an optical body surface motion management in deep breath hold.

Patients and Methods

Forty-five patients diagnosed with locally advanced pancreatic cancer were treated with stereotactic body radiotherapy in 3 or 5 fractions, and received varying BED₁₀ (median 79.5 Gy) from April 2017 to December 2020. All patients were treated in deep breath hold with OSMS-AlignRT used as optical body surface motion management. Thirty-three patients received systemic treatment before and/or after stereotactic body radiotherapy, and twelve patients received no systemic treatment. In this retrospective, observational, single-arm study, primary endpoints were overall survival and freedom from local progression (ie, local control). Secondary endpoints were progression-free survival and toxicity. Actuarial survival analysis and univariate analysis were investigated.

Results

Data from forty-five patients were analyzed. Median follow-up was 15 months. One-year freedom from local progression and survival were 95.5% and 71.1%, respectively. Median progression-free survival was 14 months. Median overall survival from diagnosis for all patients was 17 months, and 19 months for patients alive at the time of analysis. No patient had >G2 toxicity.

Conclusion

Stereotactic body radiotherapy for locally advanced pancreatic cancer using OSMS-AlignRT as optical body surface motion management in deep breath hold patients is an effective and safe local treatment option, with no >G2 toxicity, and could be a promising therapeutic option with acceptable toxicity, either as a single treatment or in a multimodal regimen. OSMS-AlignRT provided accurate and reliable body surface motion management during stereotactic body radiotherapy.

Role of stereotactic body radiation in the enhancement of the quality of life in locally advanced pancreatic adenocarcinoma: a systematic review

INTRODUCTION

Up to 30% of pancreatic cancer patients initially present locally advanced (LAPC). Stereotactic body radiation therapy (SBRT) may be an additional palliative treatment option when curative resection is no longer achievable. Our systematic review aimed to assess the effect of SBRT on the quality of life in LAPC.

METHODS

We searched five databases until June 29th, 2021, for original articles that reported on SBRT for histologically proven LAPC in adults. Data were extracted on study characteristics, SBRT and additional therapy regimen, pain, biliary complications, nutrition, quality of life and other patient-reported outcomes. Statistical analyses were performed for population and survival data.

RESULTS

11 case series studies comprising 292 patients with a median age of 66 (range 34-89) years were included in the final analysis. The weighted average BED2;10 (radiation biologically effective dose, equivalent dose in 2 Gy fractions) was 54 Gy, delivered in 3 to 6 fractions. The individual studies used different scales and endpoints, not allowing a meta-analysis. Pain generally appeared to be improved by SBRT. SBRT significantly reduced jaundice. Local control was achieved in 71.7% of patients. Weight loss and nausea also tended to improve after SBRT.

CONCLUSION

SBRT of locally advanced irresectable pancreatic cancer is a promising approach for achieving local control and improving the quality of life. However, randomized controlled trials with larger cohorts are needed to assess the value of SBRT in pancreatic cancer therapy.

Stereotactic Ablative Radiotherapy Using CALYPSO® Extracranial Tracking for Intrafractional Tumor Motion Management-A New Potential Local Treatment for Unresectable Locally Advanced Pancreatic Cancer? Results from a Retrospective Study

(1) Background: The aim of this study was to evaluate the efficacy and safety of SABR for LAPC using Calypso® Extracranial Tracking for intrafractional, fiducial-based motion management, to present this motion management technique, as there are yet no published data on usage of Calypso® during SABR for LAPC, and to report on our clinical outcomes. (2) Methods: Fifty-four patients were treated with SABR in one, three, or five fractions, receiving median BED10 = 112.5 Gy. Thirty-eight patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Actuarial survival analysis and univariate analysis were investigated. (3) Results: Median follow-up was 20 months. Median OS was 24 months. One-year FFLP and one-year OS were 100% and 90.7%, respectively. Median PFS was 18 months, and one-year PFS was 72.2%. Twenty-five patients (46.3%) were alive at the time of analysis, and both median FU and OS for this subgroup were 26 months. No acute/late toxicity > G2 was reported. (4) Conclusions: SABR for LAPC using Calypso® presented as an effective and safe treatment and could be a promising local therapeutic option with very acceptable toxicity, either as a single treatment or in a multimodality regimen. Dose escalation to the tumor combined with systemic treatment could yield better clinical outcomes.

Pain Relief after Stereotactic Radiotherapy of Pancreatic Adenocarcinoma: An Updated Systematic Review

Severe pain is frequent in patients with locally advanced pancreatic ductal adenocarcinoma (PDCA). Stereotactic body radiotherapy (SBRT) provides high local control rates in these patients. The aim of this review was to systematically analyze the available evidence on pain relief in patients with PDCA. We updated our previous systematic review through a search on PubMed of papers published from 1 January 2018 to 30 June 2021. Studies with full available text, published in English, and reporting pain relief after SBRT on PDCA were included in this analysis. Statistical analysis was carried out using the MEDCALC statistical software. All tests were two-sided. The I2 statistic was used to quantify statistical heterogeneity (high heterogeneity level: >50%). Nineteen papers were included in this updated literature review. None of them specifically aimed at assessing pain and/or quality of life. The rate of analgesics reduction or suspension ranged between 40.0 and 100.0% (median: 60.3%) in six studies. The pooled rate was 71.5% (95% CI, 61.6−80.0%), with high heterogeneity between studies (Q2 test: p < 0.0001; I2 = 83.8%). The rate of complete response of pain after SBRT ranged between 30.0 and 81.3% (median: 48.4%) in three studies. The pooled rate was 51.9% (95% CI, 39.3−64.3%), with high heterogeneity (Q2 test: p < 0.008; I2 = 79.1%). The rate of partial plus complete pain response ranged between 44.4 and 100% (median: 78.6%) in nine studies. The pooled rate was 78.3% (95% CI, 71.0−84.5%), with high heterogeneity (Q2 test: p < 0.0001; I2 = 79.4%). A linear regression with sensitivity analysis showed significantly improved overall pain response as the EQD2α/β:10 increases (p: 0.005). Eight papers did not report any side effect during and after SBRT. In three studies only transient acute effects were recorded. The results of the included studies showed high heterogeneity. However, SBRT of PDCA resulted reasonably effective in producing pain relief in these patients. Further studies are needed to assess the impact of SBRT in this setting based on Patient-Reported Outcomes.

Current status of non-surgical treatment of locally advanced pancreatic cancer

Pancreatic cancer is the 7th leading cause of death due to cancer in industrialized countries and the 11th most common cancer globally, with 458918 new cases (2.5% of all cancers) and 432242 deaths (4.5% of all cancer deaths) in 2018. Unfortunately, 80% to 90% of the patients present with unresectable disease, and the reported 5-year survival rate range between 10% and 25%, even after successful resection with tumor-free margins. Systemic chemotherapy, radiotherapy, and minimally invasive image-guided procedures that have emerged over the past years, are used for the management of non-operable PC. This review focuses on currently available non-surgical options of locally advanced pancreatic cancer.

Carbon-Ion Beam Irradiation and the miR-200c Mimic Effectively Eradicate Pancreatic Cancer Stem Cells Under in vitro and in vivo Conditions

Purpose

The study investigated the molecular mechanisms that killed pancreatic cancer cells, including cancer stem cells (CSCs), by carbon ion beam irradiation alone or in combination with miRNA-200c under in vitro and in vivo conditions.

Methods

Human pancreatic cancer (PC) cells, PANC1 and PK45, were treated with carbon-ion beam irradiation alone or in combination with microRNA-200c (miR-200c) mimic. Cell viability assay, colony and spheroid formation assay, quantitative real-time PCR analysis of apoptosis-, autophagy-, and angiogenesis-related gene expression, xenograft tumor control and histopathological analyses were performed.

Results

The cell viability assay showed that transfection of the miRNA-200c (10 nM) mimic into pancreatic CSC (CD44+/ESA+) and non-CSC (CD44-/ESA-) significantly suppressed proliferation of both types of cell populations described above. Combining carbon-ion beam irradiation with the miRNA-200c mimic significantly reduced the colony as well as spheroid formation abilities compared to that observed with the treatment of carbon-ion beam alone or X-ray irradiation combined with the miRNA-200c mimic. Moreover, the combination of carbon ion beam irradiation and miRNA-200c mimic increased the expression of apoptosis-related gene BAX, autophagy-related genes Beclin-1 and p62, addition of gemcitabine (GEM) further enhanced the expression of these genes. In vivo data showed that carbon-ion beam irradiation in combination with the miRNA-200c mimic effectively suppressed xenograft tumor growth and significantly induced tumor necrosis and cavitation.

Conclusion

The combination of miRNA-200c mimic and carbon ion beam irradiation may be powerful radiotherapy that significantly kills pancreatic cancer cells containing CSCs and enhances the effect of carbon-ion beam irradiation compared to carbon-ion beam irradiation alone.

Phase I study of dose-escalated stereotactic body radiation therapy for locally advanced pancreatic head cancers: Initial clinical results

Purpose

To establish the maximum tolerated dose (MTD) of stereotactic body radiation therapy (SBRT) for locally advanced pancreatic head cancers.

Methods

A total of 16 patients were included in the single‐institution phase I dose‐escalation study. The initial dose level was 35 Gy in five fractions, doses were then sequentially escalated to 37.5 Gy, 40 Gy, 42.5 Gy, and 45 Gy. The dose‐limiting toxicity (DLT) was defined as III/IV GI (gastrointestinal) toxicity.

Results

A total of 16 patients with locally advanced pancreatic head cancers were analyzed, 14 patients had received gemcitabine or S1‐based chemotherapy. Median OS and LPFS were 14.5 months and 12.5 months, respectively; The OS rates at 1 and 2 years were 68.8% and 25%, respectively. No grade 3 or 4 acute or late GI toxicities were observed. Grade 3 toxicities were observed in four patients with three hematologic toxicities and one biliary obstruction for acute toxicities, G1–2 of GI late toxicity were in 31.25% of patients.

Conclusions

SBRT doses ranging from 35 to 45 Gy in five fractions could be given for patients with locally advanced pancreatic head cancers without severe GI toxicities, whereas the side effect of biliary obstruction should be paid more attention.

Trial registration

Clinical trials:NCT02716207.

Phase I Trial of Stereotactic Body Radiation Therapy Dose Escalation in Pancreatic Cancer

PURPOSE

Stereotactic body radiation therapy (SBRT) has demonstrated encouraging local tumor control rates in the treatment of pancreatic cancer, yet we lack prospective clinical trials evaluating dose-escalation strategies among patients treated with 5-fraction SBRT. This phase 1 dose-escalation trial was conducted to determine the maximum tolerated dose of SBRT in patients with pancreatic cancer.

METHODS AND MATERIALS

Thirty patients with pancreatic cancer were enrolled and treated with 40, 45, or 50 Gy SBRT in 5 fractions with doses determined using a time-to-event continual reassessment method trial design. Systemic therapy was permitted before and after SBRT, but not mandated by the study protocol. Toxicity was the primary study endpoint, and any grade ≥3 acute or late toxicity potentially attributable to SBRT was considered a dose-limiting toxicity. Secondary endpoints included local progression, distant progression, and overall survival.

RESULTS

The median follow up from SBRT was 8.9 months (range, 1.7-62.6 months). Nineteen patients (63%) had locally advanced disease, 3 patients (10%) had metastatic disease, and 8 patients (27%) had medically unresectable disease. Three patients (10%) received 40 Gy, 16 patients (53%) received 45 Gy, and 11 patients (37%) received 50 Gy. Seven patients (23%) experienced grade ≤2 acute toxicity, and 2 patients (6.7%) experienced grade 4 to 5 late toxicity, both of which occurred in the 45 Gy group. Median survival time was 17.1 months from the time of diagnosis and 9.8 months from SBRT. The 1-year cumulative incidence of local progression was 14.2% (95% confidence interval, 4.2%-30%).

CONCLUSIONS

This dose-escalation trial evaluated high-dose SBRT delivered in 5 fractions, and overall demonstrated favorable local control and survival, but was associated with nontrivial rates of severe late gastrointestinal toxicity potentially attributable to radiation. Further prospective studies are needed to define the safety and efficacy of high-dose SBRT in patients with pancreatic cancer.

Magnetic nanoparticle hyperthermia for treating locally advanced unresectable and borderline resectable pancreatic cancers: the role of tumor size and eddy-current heating

Purpose:

Tumor volume largely determines the success of local control of borderline resectable and locally advanced pancreatic cancer with current therapy. We hypothesized that a tumor-mass normalized dose of magnetic nanoparticle hyperthermia (MNPH) with alternating magnetic fields (AMFs) reduces the effect of tumor volume for treatment.

Methods:

18 female athymic nude mice bearing subcutaneous MiaPaCa02 human xenograft tumors were treated with MNPH following intratumor injections of 5.5 mg Fe/g tumor of an aqueous suspension of magnetic iron-oxide nanoparticles. Mice were randomly divided into control (n = 5) and treated groups having small (0.15 ± 0.03 cm³, n = 4) or large (0.30 ± 0.06 cm³, n = 5) tumors. We assessed the clinical feasibility of this approach and of pulsed AMF to minimize eddy current heating using a finite-element method to solve a bioheat equation for a human-scale multilayer model.

Results:

Compared to the control group, both small and large MiaPaCa02 subcutaneous tumors showed statistically significant growth inhibition. Conversely, there was no significant difference in tumor growth between large and small tumors. Both computational and xenograft models demonstrated higher maximum tumor temperatures for large tumors compared to small tumors. Computational modeling demonstrates that pulsed AMF can minimize nonspecific eddy current heating.

Conclusions:

MNPH provides an advantage to treat large tumors because the MION dose can be adjusted to increase power. Pulsed AMF, with adjusted treatment time, can enhance MNPH in challenging cases such as low MION dose in the target tissue and/or large patients by minimizing nonspecific eddy current heating without sacrificing thermal dose to the target. Nanoparticle heterogeneity in tumors remains a challenge for continued research.

Controversies in radiotherapy for pancreas cancer

The management of pancreatic adenocarcinoma remains an area of controversy and ongoing discovery. Despite advances in surgical and radiation techniques, as well as chemotherapeutic agents, outcomes of patients diagnosed with this devastating malignancy remain poor. This article aims to review the available literature evaluating the efficacy of adjuvant, neoadjuvant, and definitive radiation therapy. We will also highlight areas of ongoing research efforts being carried out to improve outcomes in this patient population.

The Landmark Series: Locally Advanced Pancreatic Cancer and Ablative Therapy Options

Locally advanced pancreatic cancer (LAPC) is a challenging disease to treat. There is consensus that systemic chemotherapy should be the first line of therapy for most patients. However, there is no consensus on how to manage those patients who do not have sufficient response to become candidates for resection but also do not have distant progression after weeks or months of systemic therapy. Radiation therapy is the most commonly used and best-studied local ablative therapy. One recent randomized controlled trial (LAP-07) failed to demonstrate an overall survival benefit for conventional chemoradiation therapy after induction chemotherapy versus chemotherapy alone. This study had several limitations, and ongoing studies are re-evaluating the role of chemoradiation after more effective chemotherapy regimens as well as more advanced radiation techniques. In parallel, there has been increasing interest in other thermal and non-thermal methods of ablation. In particular, irreversible electroporation has gained traction for treatment of LAPC, with at least one ongoing randomized controlled trial designed to address its role compared with systemic chemotherapy alone. Multiple preclinical and clinical studies are investigating combinations of local ablation and immunotherapy with the goal of generating immune responses that will meaningfully improve outcomes.

SPARC, a phase-I trial of pre-operative, margin intensified, stereotactic body radiation therapy for pancreatic cancer

BACKGROUND AND PURPOSE

Following resection of pancreatic cancer, risk of positive margins and local recurrence remain high, especially for borderline-resectable pancreatic cancer (BRPC). We aimed to establish the maximum tolerated dose of a margin-intensified five-fraction stereotactic body radiotherapy (SBRT) regimen designed to treat the region at risk.

MATERIALS AND METHODS

We conducted a prospective multicentre phase-1 rolling-six dose-escalation study. BRPC patients received pre-operative SBRT, with one dose to the primary tumour and an integrated boost to the region where tumour was in contact with vasculature. Four dose-levels were proposed, with starting dose 30 Gy to primary PTV and 45 Gy to boost volume (PTV_R), in five daily fractions. Primary endpoint was maximum tolerated dose (MTD), defined as highest dose where zero of three or one of six patients experienced dose-limiting toxicity (DLT).

RESULTS

Twelve patients were registered, eleven received SBRT. Radiotherapy was well tolerated with all treatment completed as scheduled. Dose was escalated one level up from starting dose without encountering any DLT (prescribed 32.5 Gy PTV, 47.5 Gy PTV_R). Nine serious adverse reactions or events occurred (seven CTCAE Grade 3, two Grade 4). Two patients went on to have surgical resection. Median overall survival for SBRT patients was 8.1 months. The study closed early when it was unable to recruit to schedule.

CONCLUSION

Toxicity of SBRT was low for the two dose-levels that were tested, but MTD was not established. Few patients subsequently underwent resection of pancreatic tumour after SBRT, and it is difficult to draw conclusions regarding the safety or toxicity of these therapies in combination.

[Stereotactic body radiotherapy for locally advanced pancreatic cancer: A systemic review]

Stereotactic body radiation therapy (SBRT) for locally advanced pancreatic cancer (LAPC) is an emerging treatment option. Most studies showed local control of approximately 75% with no evidence of improved overall survival. Gastrointestinal toxicities could be significant, ranging up to 22% for acute toxicities≥grade 3+ and 44% for late toxicities≥grade 3+. Currently, no standardized guidelines for treatment and management scheme. We conducted a systemic review of published prospective and retrospective trials to evaluate the efficacy, safety, technical data, and discuss future directions.

Basics and Frontiers on Pancreatic Cancer for Radiation Oncology: Target Delineation, SBRT, SIB technique, MRgRT, Particle Therapy, Immunotherapy and Clinical Guidelines

Pancreatic cancer represents a modern oncological urgency. Its management is aimed to both distal and local disease control. Resectability is the cornerstone of treatment aim. It influences the clinical presentation’s definitions as up-front resectable, borderline resectable and locally advanced (unresectable). The main treatment categories are neoadjuvant (preoperative), definitive and adjuvant (postoperative). This review will focus on (i) the current indications by the available national and international guidelines; (ii) the current standard indications for target volume delineation in radiotherapy (RT); (iii) the emerging modern technologies (including particle therapy and Magnetic Resonance [MR]-guided-RT); (iv) stereotactic body radiotherapy (SBRT), as the most promising technical delivery application of RT in this framework; (v) a particularly promising dose delivery technique called simultaneous integrated boost (SIB); and (vi) a multimodal integration opportunity: the combination of RT with immunotherapy.

Preoperative radiotherapy improves overall survival of pT4 pancreatic ductal adenocarcinoma patients after surgical resection

OBJECTIVE

The aim of delivering radiotherapy for pancreatic ductal adenocarcinoma patients was to sterilize vessel margin, increase R0 resection rate and delay local progression. Whether preoperative radiotherapy could prolong overall survival of surgical candidates remained unknown.

METHODS

Pancreatic ductal adenocarcinoma patients receiving radical resection from surveillance, epidemiology and end result database were enrolled. Propensity score matching was conducted to balance difference in baseline characteristics, and survival analyses were performed to compare overall survival between preoperative radiotherapy and upfront resection groups. Cox proportional hazard regression model and subgroup analyses were utilized to identify prognostic factors.

RESULTS

A total of 11 665 and 597 pancreatic ductal adenocarcinoma patients receiving upfront resection and preoperative radiotherapy followed by resection from 2004 to 2016 were identified, respectively, while baseline characteristics were distinct between groups. After propensity score matching, preoperative radiotherapy was not associated with better overall survival (upfront resection vs preoperative radiotherapy, 26 vs 27 months). Subgroup analyses showed that preoperative radiotherapy was a protective factor in pT4 (hazard ratio = 0.64, 95% confidence interval: 0.47-0.88) but a negative predictor in pT1 (hazard ratio = 1.79, 95% confidence interval: 1.08-2.97) patient populations. Survival analyses showed that preoperative radiotherapy improved overall survival of patients with pT4 stage (upfront resection vs preoperative radiotherapy, 19 vs 25 months) and involvement of celiac axis, superior mesenteric artery and aorta (upfront resection vs preoperative radiotherapy, 20 vs 27 months), while preoperative radiotherapy was associated with worse overall survival in patients with pT1 tumor (upfront resection vs preoperative radiotherapy, 39 vs 24 months).

CONCLUSION

Preoperative radiotherapy could improve survival of resected pancreatic ductal adenocarcinoma patients with pT4 stage or with celiac axis, superior mesenteric artery and aorta invasion.

Clinical Limitations of Photon, Proton and Carbon Ion Therapy for Pancreatic Cancer

Introduction: Despite improvements in radiation therapy, chemotherapy and surgical procedures over the last 30 years, pancreatic cancer 5-year survival rate remains at 9%. Reduced stroma permeability and heterogeneous blood supply to the tumour prevent chemoradiation from making a meaningful impact on overall survival. Hypoxia-activated prodrugs are the latest strategy to reintroduce oxygenation to radioresistant cells harbouring in pancreatic cancer. This paper reviews the current status of photon and particle radiation therapy for pancreatic cancer in combination with systemic therapies and hypoxia activators. Methods: The current effectiveness of management of pancreatic cancer was systematically evaluated from MEDLINE^® database search in April 2019. Results: Limited published data suggest pancreatic cancer patients undergoing carbon ion therapy and proton therapy achieve a comparable median survival time (25.1 months and 25.6 months, respectively) and 1-year overall survival rate (84% and 77.8%). Inconsistencies in methodology, recording parameters and protocols have prevented the safety and technical aspects of particle therapy to be fully defined yet. Conclusion: There is an increasing requirement to tackle unmet clinical demands of pancreatic cancer, particularly the lack of synergistic therapies in the advancing space of radiation oncology.

Dose Escalation in Stereotactic Body Radiation Therapy for Pancreatic Cancer: A Meta-Analysis

OBJECTIVE

To determine whether increasing biologically effective dose (BED) with stereotactic body radiation therapy (SBRT) is associated with improved local control (LC) or toxicities in patients with locally advanced pancreatic cancer.

METHODS

A PICOS/PRISMA/MOOSE selection protocol was used to identify 15 studies across 12 institutions in 5 countries where patients received definitive SBRT for nonmetastatic disease. Biologically equivalent doses were calculated with an α/β of 10 (ie, BED10) for LC and acute toxicity and 3 (ie, BED3) for late toxicity. Fixed and random effects models were used to characterize LC and grade 3/4 toxicities by BED.

RESULTS

There were 508 patients included with a median follow-up time of 9.1 months. The median dose was 30 Gy, and the most common regimen was 30 Gy/5 fractions. There was no significant difference in LC rates at 1 year between the BED10<70 Gy versus ≥70 Gy groups, with an estimate of 0.60 (95% confidence interval [CI], 0.36-0.81) versus 0.83 (95% CI, 0.63-0.97), respectively. There was no significant difference in acute toxicity rates between the BED10<70 Gy versus ≥70 Gy groups, with an estimate of 0.02 (95% CI, 0.00-0.08) versus 0.05 (95% CI, 0.00-0.22), respectively. Given the dose distribution across studies, 3 intervals were used to characterize BED3. There were no significant differences in late toxicity among those receiving BED3<100, 100 to 200, or >200 Gy.

CONCLUSIONS

SBRT for pancreatic cancer results in LC rates of 60% to 83% and clinically significant toxicity of <7%. Increasing BED10 beyond 70 Gy was not associated with increased rates of 1-year LC or acute toxicity. Increasing BED3 beyond 100 Gy was not associated with increased rates of late toxicity.

Neoadjuvant stereotactic body radiation therapy for nonmetastatic pancreatic adenocarcinoma

Background: Neoadjuvant therapy is a strategy for resectable and borderline resectable pancreatic cancer, but a consensus approach regarding optimal management is undetermined. Neoadjuvant options include chemotherapy with/without radiotherapy. Stereotactic body radiation therapy (SBRT) is a novel radiation technique that may provide benefit over conventionally fractionated radiation therapy (CFRT) in the neoadjuvant setting. The purpose of the present study is to determine neoadjuvant treatment with SBRT to other neoadjuvant treatment options for patients with resectable pancreatic cancer. Material and methods: The National Cancer Database was queried (2004-2015) for patients with nonmetastatic pancreatic adenocarcinoma receiving neoadjuvant therapy followed by pancreatectomy. Patients were categorized based on the type of neoadjuvant treatment administered. Statistics included temporal trend assessment by annual percent change (APC), predictors for SBRT by multivariable logistic regression, Kaplan-Meier overall survival (OS) analysis without and with propensity matching, and Cox proportional hazards modeling for univariable OS analysis. Results: Of 5828 patients, 332 (5.7%), 3234 (55.5%) and 2262 (38.8%) received neoadjuvant chemo-SBRT, chemotherapy, and chemo-CFRT, respectively. SBRT utilization increased from 0% in 2004 to 9.5% in 2015, with a greater APC after 2010 (p < .001). SBRT was more likely to be utilized in patients with T3-4 and node-positive disease (p < .05 for all). The chemo-SBRT cohort was associated with a higher OS rate before and after propensity matching (p < .05 for both). The rate of R0 resection was higher in radiotherapy groups than the chemotherapy cohort (p < .001). Conclusions: Utilization of neoadjuvant SBRT for pancreatic cancer is increasing. In the neoadjuvant setting, chemo-SBRT may improve R0 resection and OS over chemotherapy and chemo-CFRT, although confirmatory prospective studies are needed for confirmation.

Application of stereotactic body radiotherapy in advanced pancreatic cancers in Australia

INTRODUCTION

The majority of pancreatic cancers present locally advanced and carry a high mortality rate. Treatment is challenging, with mixed data suggesting use of chemotherapy alone or in combination with radiotherapy. The use of radiotherapy has previously been limited due to lack of ability to deliver radiation to the tumour mass without causing significant toxicity to surrounding organs. Stereotactic body radiotherapy (SBRT) allows delivery of higher biologically equivalent dose in a shorter treatment duration. We sought to investigate the safety and application of this technique in our centre.

METHOD

We enrolled 27 patients from 2015, identified as locally advanced unresectable with histologically confirmed, non-metastatic, pancreatic adenocarcinoma. All patients had endoscopically inserted fiducial markers and where possible concurrent chemotherapy was administered. Dose schedules ranged from 25 to 42 Gy in 5 or 3 fractions.

RESULTS

With an overall median follow up of 9 months (range, 3-32.7), the median survival was 11.6 months. Of those alive at 1 year, the local control rate was 67%. Six patients had Grade 3 toxicity, and other six had Grade 2 toxicity. None had Grade 4 or above toxicity. The most common symptom recorded was fatigue.

CONCLUSION

SBRT for locally advanced pancreatic cancer is technically complex but feasible in a high volume centre. SBRT is unique, allowing safe delivery of high radiation dose resulting in good local control and decreases treatment time making it an attractive option for patients with unresectable pancreatic cancer.

Technical Assessment of an Automated Treatment Planning on Dose Escalation of Pancreas Stereotactic Body Radiotherapy

BACKGROUND

Stereotactic body radiotherapy has been suggested to provide high rates of local control for locally advanced pancreatic cancer. However, the close proximity of highly radiosensitive normal tissues usually causes the labor-intensive planning process and may impede further escalation of the prescription dose.

PURPOSE

The present study aims to evaluate the consistency and efficiency of Pinnacle Auto-Planning for pancreas stereotactic body radiotherapy with original prescription and escalated prescription.

METHODS

Twenty-four patients with pancreatic cancer treated with stereotactic body radiotherapy were studied retrospectively. The prescription is 40 Gy over 5 consecutive fractions. Most of patients (n = 21) also had 3 other different dose-level targets (6 Gy/fraction, 5 Gy/fraction, and 4 Gy/fraction). Two types of plans were generated by Pinnacle Auto-Planning with the original prescription (8 Gy/fraction, 6 Gy/fraction, 5 Gy/fraction, and 4 Gy/fraction) and escalated prescription (9 Gy/fraction, 7 Gy/fraction, 6 Gy/fraction, and 5 Gy/fraction), respectively. The same Auto-Planning template, including beam geometry, intensity-modulated radiotherapy objectives and intensity-modulated radiotherapy optimization parameters, were utilized for all the auto-plans in each prescription group. The intensity-modulated radiotherapy objectives do not include any manually created structures. Dosimetric parameters including percentage volume of PTV receiving 100% of the prescription dose, percentage volume of PTV receiving 93% of the prescription dose, and consistency of the dose-volume histograms of the target volumes were assessed. Dmax and D1 cc of highly radiosensitive organs were also evaluated.

RESULTS

For all the pancreas stereotactic body radiotherapy plans with the original or escalated prescriptions, auto-plans met institutional dose constraints for critical organs, such as the duodenum, small intestine, and stomach. Furthermore, auto-plans resulted in acceptable planning target volume coverage for all targets with different prescription levels. All the plans were generated in a one-attempt manner, and very little human intervention is necessary to achieve such plan quality.

CONCLUSIONS

Pinnacle3 Auto-Planning consistently and efficiently generate acceptable treatment plans for multitarget pancreas stereotactic body radiotherapy with or without dose escalation and may play a more important role in treatment planning in the future.

Review and current state of radiation therapy for locally advanced pancreatic adenocarcinoma

Pancreatic cancer is characterized by a high rate of metastatic spread and overall poor prognosis. Yet 30% of patients have progressive local disease at the time of death, and local progression can cause significant morbidity. Approximately 30-40% of patients present with locally advanced pancreatic cancer (LAPC) that is not surgically resectable, and the optimal treatment for these patients continues to evolve. The role of radiation in the management of LAPC is an area of controversy, and the recent LAP07 randomized trial reported no survival benefit of radiation following gemcitabine plus or minus erlotinib. However, the efficacy of modern systemic regimens has improved since the design of the LAP07 study, and radiation therapy may be of greater benefit in the context of more effective systemic therapy. Advances in radiation delivery including the increasing use of stereotactic body radiation therapy (SBRT) have the potential to improve outcomes through dose escalation and better treatment tolerability. In addition, the combination of radiation therapy and immune therapy is an area of promising research. These advances suggest that radiation therapy will continue to play an integral role in the management of LAPC.

Dose escalation for locally advanced pancreatic cancer: How high can we go?

Purpose

There are limited treatment options for locally advanced, unresectable pancreatic cancer (LAPC) and no likelihood of cure without surgery. Radiation offers an option for local control, but radiation dose has previously been limited by nearby bowel toxicity. Advances in on-board imaging and treatment planning may allow for dose escalation not previously feasible and improve local control. In preparation for development of clinical trials of dose escalation in LAPC, we undertook a dosimetric study to determine the maximum possible dose escalation while maintaining known normal tissue constraints.

Methods and Materials

Twenty patients treated at our institution with either SBRT or dose-escalated hypofractionated IMRT (DE-IMRT) were re-planned using dose escalated SBRT to 70 Gy in 5 fractions to the GTV and 40 Gy in 5 fractions to the PTV. Standard accepted organ at risk (OAR) constraints were used for planning. Descriptive statistics were generated for homogeneity, conformality, OAR's and GTV/PTV.

Results

Mean iGTV coverage by 50 Gy was 91% (±0.07%), by 60 Gy was 61.3% (±0.08%) and by 70 Gy was 24.4% (±0.05%). Maximum PTV coverage by 70 Gy was 33%. Maximum PTV coverage by 60 Gy was 77.5%. The following organ at risk (OAR) constraints were achieved for 90% of generated plans: Duodenum V20 < 30 cc, V30 < 3 cc, V35 < 1 cc; Small Bowel V20 < 15 cc, V30 < 1 cc, V35 < 0.1 cc; Stomach V20 < 20 cc, V30 < 2 cc, V35 < 1 cc. V40 < 0.5 cc was achieved for all OAR.

Conclusions

Dose escalation to 60 Gy is dosimetrically feasible with adequate GTV coverage. The identified constraints for OAR's will be used in ongoing clinical trials.

Stereotactic ablative radiotherapy (SABR) as primary, adjuvant, consolidation and re-treatment option in pancreatic cancer: scope for dose escalation and lessons for toxicity

BACKGROUND

Stereotactic ablative radiotherapy (SABR) offers an alternative treatment for pancreatic cancer, with the potential for improved tumour control and reduced toxicity compared with conventional therapies. However, optimal dose planning and delivery strategies are unelucidated and gastro-intestinal (GI) toxicity remains a key concern.

METHODS

Patients with inoperable non-metastatic pancreatic cancer who received CyberKnife® SABR (18-36 Gy) in three fractions as primary, adjuvant, consolidation or re-treatment options were studied. Patient individualised planning and delivery variables were collected and their impact on patient outcome examined. Linear-quadratic (LQ) radiobiology modelling methods were applied to assess SABR parameters against a conventional fractionated radiotherapy schedule.

RESULTS

In total 42 patients were included, 37 (88%) of whom had stage T4 disease. SABR was used > 6 months post-primary therapy to re-treat residual disease in 11 (26.2%) patients and relapsed disease in nine (21.4%) patients. SABR was an adjuvant to other primary therapy for 14 (33.3%) patients and was the sole primary therapy for eight (19.0%) patients. The mean (95% CI) planning target volume (PTV), prescription isodose, percentage cover, minimum dose to PTV and biological effective dose (BED) were 76.3(63.8-88.7) cc, 67.3(65.2-69.5)%, 96.6(95.5-97.7)%, 22.3(21.0-23.6) Gy and 50.3(47.7-53.0) Gy, respectively. Only 3/37 (8.1%) patients experienced Grade 3 acute toxicities. Two (4.8%) patients converted to resectable status and median freedom-from-local-progression (FFLP) and overall survival (OS) were 9.8 and 8.4 months, respectively. No late toxicity was experienced in 27/32 (84.4%) patients; however, four (12.5%) patients - of whom two had particularly large PTV, two had sub-optimal number of fiducials and three breached organ-at-risk (OAR) constraints-showed Grade 4 duodenal toxicities. Longer delivery time, extended treatment course and reduced percentage coverage additionally associated with late toxicity, likely reflecting parameters typically applied to riskier patients. Larger PTV size and longer treatment course associated with OS. Comparator regimen LQ modelling analysis indicated 50% of patients received minimum PTV doses less potent than a conventional radiotherapy regimen, indicating scope for dose escalation.

CONCLUSION

The results demonstrate the value of SABR for a range of indications in pancreatic cancer. Dose escalation to increase BED may improve FFLP and OS in inoperable, non-metastatic disease: however concomitant enhanced stringency for duodenal protection is critical, particularly for patients where SABR is more challenging.

Stereotactic radiotherapy of pancreatic cancer: a systematic review on pain relief

Locally advanced pancreatic carcinoma (LAPC) has a poor prognosis and the purpose of treatment is survival prolongation and symptom palliation. Radiotherapy has been reported to reduce pain in LAPC. Stereotactic RT (SBRT) is considered as an emerging radiotherapy technique able to achieve high local control rates with acceptable toxicity. However, its role in pain palliation is not clear. To review the impact on pain relief with SBRT in LAPC patients, a literature search was performed on PubMed, Scopus, and Embase (January 2000-December 2017) for prospective and retrospective articles published in English. Fourteen studies (479 patients) reporting the effect of SBRT on pain relief were finally included in this analysis. SBRT was delivered with both standard and/or robotic linear accelerators. The median prescribed SBRT doses ranged from 16.5 to 45 Gy (median: 27.8 Gy), and the number of fractions ranged from 1 to 6 (median: 3.5). Twelve of the 14 studies reported the percentage of pain relief (in patients with pain at presentation) with a global overall response rate (complete and partial response) of 84.9% (95% CI, 75.8%-91.5%), with high heterogeneity (Q ² test: P<0.001; I2=83.63%). All studies reported toxicity data. Acute and late toxicity (grade ≥3) rates were 3.3%-18.0% and 6.0%-8.2%, respectively. Reported gastrointestinal side effects were duodenal obstruction/ulcer, small bowel obstruction, duodenal bleeding, hemorrhage, and gastric perforation. SBRT achieves pain relief in most patients with pancreatic cancer with an acceptable gastrointestinal toxicity rate. Further prospective studies are needed to define optimal dose/fractionation and the best systemic therapies modality integration to reduce toxicity and improve the palliative outcome. Finally, the quality of life and, particularly, pain control should be considered as an endpoint in all future trials on this emerging treatment technique.

Current and emerging radiotherapy strategies for pancreatic adenocarcinoma: stereotactic, intensity modulated and particle radiotherapy

The role of radiotherapy for locally advanced pancreatic cancer (LAPC) is unclear based on studies that used conventional doses and fractionation schedules. Modern radiotherapy techniques have not been studied in depth, however. We reviewed the literature on emerging methods of delivering higher doses of conformal radiotherapy using stereotactic body radiation, intensity modulated radiation, and particle beam radiation, highlighting clinical outcomes and toxicities. The literature review suggests low rates of acute and late toxicities when higher doses of radiation are given with careful attention to normal tissue dose constraints, including for stereotactic body radiotherapy (SBRT), escalated doses with intensity modulated radiation therapy (IMRT), and particle-based therapy. Retrospective evidence suggests prolonged survival for patients who receive biological equivalent doses above 70 Gy. Prospective trials that evaluate modern radiotherapy techniques are warranted for LAPC.

How Histopathologic Tumor Extent and Patterns of Recurrence Data Inform the Development of Radiation Therapy Treatment Volumes in Solid Malignancies

The ability to deliver highly conformal radiation therapy using intensity-modulated radiation therapy and particle therapy provides for new opportunities to improve patient outcomes by reducing treatment-related morbidities following radiation therapy. By reducing the volume of normal tissue exposed to radiation therapy (RT), while also allowing for the opportunity to escalate the dose of RT delivered to the tumor, use of conformal RT delivery should also provide the possibility of expanding the therapeutic index of radiotherapy. However, the ability to safely and confidently deliver conformal RT is largely dependent on our ability to clearly define the clinical target volume for radiation therapy, which requires an in-depth knowledge of histopathologic extent of different tumor types, as well as patterns of recurrence data. In this article, we provide a comprehensive review of the histopathologic and radiographic data that provide the basis for evidence-based guidelines for clinical tumor volume delineation.

Stereotactic body radiotherapy (SBRT) for patients with locally advanced pancreatic cancer: A single center experience

INTRODUCTION

Despite advances in treatment, notably in systemic therapy, the prognosis of pancreatic adenocarcinoma (PADC) remains dismal. Stereotactic body radiotherapy (SBRT) is an emerging tool in the complex management of PADC. We review outcomes of SBRT for PADC at our institution.

METHODS

We reviewed patients treated with SBRT for either unresectable PADC or locally recurrent PADC after surgery. Treatment was delivered using a robotic radiosurgery system with respiratory tracking. The median prescribed dose was 30 Gy (30-35 Gy), delivered in 5-6 fractions. Toxicities were reported as per CTCAE v4.0. Survival was estimated using the Kaplan-Meier method.

RESULTS

Between October 2010 and March 2016, 21 patients were treated at our institution. The median follow-up was 7 months (range: 1-28). The 1-year local control rate was 57%. The 1-year overall survival was 25% for locally advanced patients and 67% for those with local recurrences (p = 0.27). Eighty percent of cancer related deaths were due to metastatic progression. Five patients (24%) had Grade I-II gastrointestinal acute toxicity; one patient had fatal gastrointestinal bleeding 6 months after SBRT.

CONCLUSION

In PADC, fractionated SBRT dose schedules near 30 Gy may strike the best balance of local control and bowel toxicity. More work is required to integrate pancreatic SBRT with modern systemic therapy.

Stereotactic Radiotherapy and Particle Therapy for Pancreatic Cancer

Pancreatic cancer is a devastating disease with poor survival outcomes. Recent studies have shown that the addition of radiotherapy to chemotherapy in the setting of locally advanced pancreatic cancer did not improve overall survival outcome. These studies commonly utilize conventional radiotherapy treatment fractionation and technique (typically 3-D conformal radiotherapy or intensity modulated radiotherapy). Although no clear benefit in overall survival was demonstrated in those studies, those who received radiotherapy did have a clear benefit in terms of local control. Therefore, there is increasing interest in exploring different techniques and/or modality of radiotherapy and dose/fractionation. Stereotactic radiotherapy, which employs a hypofractionated regimen, has the potential advantage of delivering a high dose of radiation to the tumor in a short period of time (typically over 5 days) with minimal dose to the surrounding normal structures. Particle therapy such as proton and carbon ion therapy are being explored as potential radiation modality that could cause greater biological damage to the tumor compared to photon treatment, with rapid dose falloff resulting in minimal to no dose to adjacent structures. This review will discuss the current literature and emerging roles of stereotactic radiotherapy and particle therapy in pancreatic cancer.

Locally Advanced Pancreatic Cancer: A Review of Local Ablative Therapies

Pancreatic cancer is typically characterized by its aggressive tumor growth and dismal prognosis. Approximately 30% of patients with pancreatic cancer present with locally advanced disease, broadly defined as having a tumor-to-artery interface >180°, having an unreconstructable portal vein or superior mesenteric vein and no signs of metastatic disease. These patients are currently designated to palliative systemic chemotherapy, though median overall survival remains poor (approximately 11 months). Therefore, several innovative local therapies have been investigated as new treatment options for locally advanced pancreatic cancer (LAPC). This article provides an overview of available data with regard to morbidity and oncological outcome of novel local therapies for LAPC.

Stereotactic Body Radiation Therapy in the Management of Upper GI Malignancies

The role of external beam radiation therapy (EBRT) in the management of upper gastrointestinal malignancies is constantly evolving. As radiation therapy techniques improve and are able to deliver more ablative doses of radiotherapy while sparing healthy tissue, radiation can be applied to a wider range of clinical scenarios. Stereotactic body radiation therapy (SBRT) allows a high dose of radiation to be delivered to a highly conformal treatment volume in a short amount of time. Another potential advantage of SBRT is its ability to increase tumor immunogenicity, while also having less of an immunosuppressive effect on the patient, as compared to conventionally fractionated radiation therapy. In so doing, SBRT may potentiate the effects of immune therapy when the two treatments are combined, thus improving therapeutic outcomes. This article provides an overview of the role of SBRT in the management of upper gastrointestinal GI malignancies and the emerging data on immune biomarkers and SBRT, with a focus on pancreatic and liver cancer.

Stereotactic body radiotherapy for locally-advanced unresectable pancreatic cancer-patterns of care and overall survival

BACKGROUND

Unresectable pancreatic cancer remains a challenging disease to treat. Stereotactic body radiotherapy (SBRT) allows for a higher biologically equivalent dose in an abbreviated course more convenient for patients and the integration of systemic therapy. We sought to investigate utilization trends and survival outcomes for patients treated with pancreatic SBRT versus conventionally fractionated radiotherapy (CFRT).

METHODS

We engaged the National Cancer Database (NCDB) from 1998-2012 and identified locally-advanced unresectable patients with histologically confirmed, non-metastatic, pancreatic adenocarcinoma who received radiotherapy. Patients who received CFRT (1.5-4.0 Gy per fraction to a dose of ≥45 Gy, n=11,879) were compared to those who received SBRT (6-15 Gy per fraction to a dose of ≥20 Gy, n=474).

RESULTS

Median follow-up was 11.0 months (18.4 months for survivors). SBRT utilization increased from 0.2% to 7.4% from 1998 to 2012 (P<0.05). On multivariable analysis, factors predictive for preferential utilization of SBRT over CFRT were later year of diagnosis, age ≥75 years, increased facility volume, and no chemotherapy in the initial treatment plan. Unadjusted median survival was 11.2 months for CFRT vs. 12.6 months for SBRT (P=0.002). Results were consistent in the propensity matched model. Variables predictive for improved survival on multivariable analysis were diagnosis after 2010, younger age, lower comorbidity score, tumor size <3 cm, nodal stage zero, and receipt of chemotherapy (P<0.05).

CONCLUSIONS

SBRT utilization has increased significantly and is associated with a small absolute improvement in overall survival (OS) compared to CFRT. The decreased treatment time, without apparent compromise in survival, makes SBRT an attractive option for patients with unresectable pancreatic cancer warranting further research.

Stereotactic Body Radiation Therapy for Pancreatic Cancer

The role of radiation therapy in the management of pancreatic cancer represents an area of some controversy. However, local disease progression remains a significant cause of morbidity and even mortality for patients with this disease. Stereotactic body radiotherapy (SBRT) is an emerging treatment option for pancreatic cancer, primarily for locally advanced (unresectable) disease as it can provide a therapeutic benefit with significant advantages for patients' quality of life over standard conventional chemoradiation. There may also be a role for SBRT as neoadjuvant therapy for patients with borderline resectable disease to allow conversion to resectability. The objective of this review is to present the data supporting SBRT in pancreatic cancer as well as the potential limitations and caveats of current studies.

Safety Study of Targeted and Localized Intra-Arterial Delivery of Gemcitabine in Patients with Locally Advanced Pancreatic Adenocarcinoma

Purpose: This is a first-in-man safety study in locally advanced pancreatic cancer (LAPC) using a targeted intra-arterial delivery catheter (RenovoCath™).

Methods: Twenty patients were enrolled in a four-stage dose escalation of intra-arterial, locally delivered gemcitabine, at doses up to 1000 mg/m². Patients' symptoms and laboratory values were monitored for safety and tolerability. Secondary endpoints included the effect on tumor size, tumor markers, and survival.

Results: One hundred one treatments were administered to 20 patients. Five patients dropped out early due to adverse events or withdrawing consent. Serious adverse events and complications were as follows: sepsis (n = 3), grade 3 neutropenia (n = 3), guide-mediated vascular dissection (n = 3), and pulmonary toxicity (n = 1). There were no cases of elevated liver or pancreatic enzymes. All sepsis cases occurred in patients with biliary stent/drains, prompting the addition of periprocedural treatment with antibiotics, which effectively prevented further sepsis in the study. Efficacy analysis was limited to 15 patients who received more than two treatments. Fifty-eight percent of these patients had a reduction in CA 19-9 tumor markers, 3 patients had tumor progression, 1 had partial response, and 11 showed disease stability. The survival rate at 12 months was 60%.

Conclusions: The results demonstrate feasibility of localized and selective intra-arterial chemotherapy delivery to the pancreas utilizing the RenovoCath. With gemcitabine, this approach is safe, with the sole prerequisite of perioperative antibiotics for patients with prior biliary drainage/stent. Efficacy results suggest a survival benefit when compared to historical control, especially in patients with prior radiation therapy.

Update on the Management of Pancreatic Cancer in Older Adults

Pancreatic cancer is more common in older adults, who are underrepresented in clinical trials and frequently under treated. Chronological age alone should not deter clinicians from offering treatment to geriatric patients, as they are a heterogeneous population. Geriatric assessment, frailty assessment tools, and toxicity risk scores help clinicians select appropriate patients for therapy. For resectable disease, surgery can be safe but should be done at a high-volume center. Adjuvant therapy is important; though there remains controversy on the role of radiation, chemotherapy is well studied and efficacious. In locally advanced unresectable disease, chemoradiation or chemotherapy alone is an option. Neoadjuvant therapy improves the chances of resectability in borderline resectable disease. Chemotherapy extends survival in metastatic disease, but treatment goals and risk-benefit ratios have to be clarified. Adequate symptom management and supportive care are important. There are now many new treatment strategies and novel therapies for this disease.

Can Stereotactic Body Radiation Therapy Be a Viable and Efficient Therapeutic Option for Unresectable Locally Advanced Pancreatic Adenocarcinoma? Results of a Phase 2 Study

PURPOSE

To assess the efficacy of stereotactic body radiotherapy in patients with unresectable locally advanced pancreatic cancer.

MATERIALS AND METHODS

All patients received a prescription dose of 45 Gy in 6 fractions. Primary end point was freedom from local progression. Secondary end points were overall survival, progression-free survival, and toxicity. Actuarial survival analysis and univariate or multivariate analysis were investigated.

RESULTS

Forty-five patients were enrolled in a phase 2 trial. Median follow-up was 13.5 months. Freedom from local progression was 90% at 2 years. On univariate ( P < .03) and multivariate analyses ( P < .001), lesion size was statistically significant for freedom from local progression. Median progression-free survival and overall survival were 8 and 13 months, respectively. On multivariate analysis, tumor size ( P < .001) and freedom from local progression ( P < .002) were significantly correlated with overall survival. Thirty-two (71%) patients with locally advanced pancreatic cancer received chemotherapy before stereotactic body radiotherapy. Median overall survival from diagnosis was 19 months. Multivariate analysis showed that freedom from local progression ( P < .035), tumor diameter ( P < .002), and computed tomography before stereotactic body radiotherapy ( P < .001) were significantly correlated with overall survival from diagnosis.

CONCLUSION

Stereotactic body radiotherapy is a safe and effective treatment for patients with locally advanced pancreatic cancer with no G3 toxicity or greater and could be a promising therapeutic option in multimodality treatment regimen.

Integration of Stereotactic Body Radiation Therapy into the Multidisciplinary Management of Pancreatic Cancer

Although most patients with pancreatic cancer die of metastatic disease, an autopsy study showed that up to one-third of patients die of predominantly local disease. This patient population stands to benefit the most from radiation, surgery, or both. Unfortunately, however, single-agent chemotherapy has had minimal benefit in pancreatic cancer, and most patients progress distantly before receiving radiation therapy (RT). With the addition of multiagent chemotherapy, patients are living longer, and RT has emerged as an important modality in preventing local progression. Standard chemoradiation delivered over 5-6 weeks has been shown to improve local control, but this approach delays full-dose systemic therapy and increases toxicity when compared to chemotherapy alone. Stereotactic body RT (SBRT) delivered in 3-5 fractions can be used to accurately target the pancreatic tumor with small margins and limited acute treatment-related toxicity. Given the favorable toxicity profile, SBRT can easily be integrated with other therapies in all stages of pancreatic cancer. However, future studies are necessary to determine optimal dose or fractionation regimens and sequencing with targeted therapies and immunotherapy. The purpose of this review is to discuss our current understanding of SBRT in the multidisciplinary management of patients with pancreatic cancer and future implications.

Stereotactic Body Radiation Therapy for Locally Advanced Pancreatic Cancer: A Systematic Review and Pooled Analysis of 19 Trials

PURPOSE

Although surgery is the standard of care for resectable pancreatic cancer (PC), standard-dose chemoradiation therapy and chemotherapy alone are suitable for patients with unresectable disease. Stereotactic body radiation therapy (SBRT) is an alternative, focused local therapy that delivers high radiation doses within a few fractions to the cancer, sparing the surrounding critical tissue. We performed a systematic review and pooled analysis of published trials to evaluate the efficacy and safety of this emerging treatment modality.

METHODS AND MATERIALS

We searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, SCOPUS, the Web of Science, and CINAHL for publications regarding SBRT for locally advanced PC. The 1-year overall survival (OS) rate was the primary endpoint, and the median OS, 2-year OS rate, 1-year locoregional control (LRC) rate, and grade 3 to 4 toxicities were the secondary endpoints. A multivariate random-effects meta-analysis was performed to calculate the aggregated OS rates at 1 and 2 years and the 1-year LRC rate.

RESULTS

A total of 19 studies, encompassing 1009 patients, were included in the present analysis. The pooled 1-year OS was 51.6% in 13 trials with data available. The median OS ranged from 5.7 to 47 months (median 17). The LRC rate at 1 year was 72.3%. Overall, the occurrence of severe adverse events did not exceed 10%. LRC appeared to correlate with the total SBRT dose and the number of fractions.

CONCLUSIONS

The advantages of SBRT in terms of treatment time, satisfactory OS, and LRC indicate that it is an effective option for inoperable PC. However, a definitive validation of this treatment modality in large randomized studies is required, owing to the nonrandomized nature of the included studies and the limitations of small single-center series that include mixed populations.

Stereotactic body radiotherapy (SBRT) in recurrent or oligometastatic pancreatic cancer : A toxicity review of simultaneous integrated protection (SIP) versus conventional SBRT

BACKGROUND

Stereotactic body radiotherapy (SBRT) in pancreatic cancer can be limited by its proximity to organs at risk (OAR). In this analysis, we evaluated the toxicity and efficacy of two different treatment approaches in patients with locally recurrent or oligometastatic pancreatic cancer.

MATERIALS AND METHODS

According to the prescription method, patients were divided in two cohorts (C1 and C2). The planning target volume (PTV) was created through a 4 mm expansion of the internal target volume. In C2, a subvolume was additionally created, a simultaneous integrated protection (SIP), which is the overlap of the PTV with the planning risk volume of an OAR to which we prescribed a reduced dose.

RESULTS

In all, 18 patients were treated (7 with local recurrences, 9 for oligometastases, 2 for both). Twelve of 23 lesions were treated without SIP (C1) and 11 with SIP (C2). The median follow-up was 12.8 months. Median overall survival (OS) was 13.2 (95% confidence interval [CI] 9.8-14.6) months. The OS rates at 6 and 12 months were 87 and 58%, respectively. Freedom from local progression for combined cohorts at 6 and 12 months was 93 and 67% (95% CI 15-36), respectively. Local control was not statistically different between the two groups. One patient in C2 experienced grade ≥3 acute toxicities and 1 patient in C1 experienced a grade ≥3 late toxicity.

CONCLUSION

The SIP approach is a useful prescription method for abdominal SBRT with a favorable toxicity profile which does not compromise local control and overall survival despite dose sacrifices in small subvolumes.