High-dose helical tomotherapy with concurrent full-dose chemotherapy for locally advanced pancreatic cancer

Use of Nab-Paclitaxel Plus Gemcitabine Followed by Hypofractionated Tomotherapy With Simultaneous Integrated Boost in Patients With Locally Advanced Pancreatic Cancer

Background and Purpose

A phase 2 study LAPACT indicated nab-paclitaxel plus gemcitabine (AG) improved outcomes of patients with locally advanced pancreatic cancer (LAPC). Conventional radiotherapy failed to show benefit, indicating high dose to volume with high risk of recurrence is needed. The high dose can be delivered through hypofractionated tomotherapy with simultaneous integrated boost (SIB). However, there is a lack of such prospective trials and more data are needed to validate the role of AG plus hypofractionated tomotherapy with SIB in patients with LAPC.

Materials and Methods

Patients with LAPC receiving AG plus tomotherapy at the Nanjing Drum Tower Hospital between 2018 and 2021 were retrospectively analyzed. The treatment was scheduled as follows: nab-paclitaxel 125 mg/m² plus gemcitabine 1,000 mg/m² on days 1 and 8 every three weeks for at least two cycles, followed by hypofractionated tomotherapy with SIB (high dose field: 50 Gy/10 fractions, the remainder: 30 Gy/10 fractions). Then patients were given AG until intolerance or disease progression.

Results

Overall, 22 patients completing the chemoradiotherapy were included. The median follow-up was 15.2 months. After the chemoradiotherapy, 5 patients achieved a partial response (PR), 15 had a stable disease (SD), and another 2 patients were with progressive disease (PD). The median progression-free survival (PFS) and overall survival (OS) were 12.8 months (95% confidence interval [CI] 4.3-21.3 months) and 16.3 months (95% CI 10.9-21.6 months), respectively. The optimal carbohydrate antigen (CA) 19-9 response and chemotherapy cycles ≥6 were correlated with favorable PFS and OS. The most common recurrent pattern was peritoneal dissemination (22.7%) and the locoregional recurrence rate was relatively low (4.5%). Treatments were well-tolerated. The most common grade ≥3 adverse event was thrombocytopenia (13.6%).

Conclusion

This study demonstrated the feasibility of AG followed by hypofractionated tomotherapy with SIB in patients with LAPC. The hypofractionated tomotherapy with SIB was safe and showed high local control rate. Further study with a larger population to validate our data is underway.

Dosimetric feasibility on hypofractionated intensity-modulated radiotherapy and simultaneous integrated boost for locally advanced unresectable pancreatic cancer with helical tomotherapy

Background

This dosimetric study on locally advanced pancreatic cancer (LAPC) and the surrounding gastrointestinal organs at risk (OARs) aimed at exploring the potential of further improving the internal dose and reducing the fractionation number by concurrent hypofractionated simultaneous integrated boost (SIB) radiotherapy using helical tomotherapy (HT).

Methods

We collected computed tomography positioning images from a LAPC study of 17 consecutive patients. Gross tumor volume (GTV)1, GTV2, and GTV3 were defined as the GTV minus a margin of 3, 6, and 9 mm from the external part in all directions, respectively. Under the same physical parameters and limited dose on normal organs, each case had 4 sets of SIB radiotherapy plans. Upon dose escalation, we statistically analyzed the difference of dosimetric parameters received by the OARs between group A [planning target volume (PTV)/GTV=50 Gy/70 Gy] and the other groups. According to the equivalent bioradiotherapy formula, we calculated the hypofractionated standard dose by converting the average tolerated dose of each OAR with the corresponding number of fractions. Then, we compared the dose and volume parameters of the gastrointestinal tract from the less-than-20-fraction modes with the corresponding gastrointestinal hypofractionated standard dose.

Results

For dose escalation, although there were a few differences in the parameters of the OAR between group A and group D, all OAR doses of group D (PTV/GTV/GTV1/GTV2/GTV3=50 Gy/70 Gy/80 Gy/90 Gy/100 Gy) were within the limited dose range. In the hypofractionated mode, there was a statistically significant difference between the gastrointestinal dose-volume parameters and the dose-limiting reference standard when the fraction number was less than 14 or 15 for group A or D, respectively.

Conclusions

The dose of the internal target can be increased to 100 Gy with 15 fractions in the hypofractionated SIB radiotherapy for LAPC with HT. The corresponding tolerance dose of OARs may also be acceptable.

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.

Locally advanced pancreatic cancer successfully treated with high-dose helical tomotherapy

Complete surgical resection is the potentially curative treatment for pancreatic cancer, but only fewer than 20% of those individuals will be found to be eligible for surgery. Here we report a 49-year-old man with locally advanced pancreatic cancer successfully treated with high-dose radiotherapy using helical tomotherapy (66 Gy/33 fractions, 2 Gy per day over 6.5 weeks). To our knowledge, this is the first reported case of locally advanced pancreatic cancer curatively treated with helical tomotherapy alone.

The Role of Radiation Therapy for Pancreatic Cancer in the Adjuvant and Neoadjuvant Settings

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Although surgery remains the only curative treatment, chemotherapy and radiation therapy are frequently used. In the adjuvant setting, radiation is usually delivered with chemotherapy to eradicate residual microscopic or macroscopic disease in the resection bed. Neoadjuvant radiation therapy has become more frequently utilized. This article reviews the historical and modern literature regarding radiation therapy in the neoadjuvant and adjuvant settings, focusing on the evolution of radiation therapy techniques and clinical trials in an attempt to identify patients best suited to receiving radiation therapy.

Dose escalation in locally advanced pancreatic cancer patients receiving chemoradiotherapy

PURPOSE

To investigate whether radiotherapy (RT) dose escalation would improve treatment outcomes without increasing severe toxicity in locally advanced pancreatic cancer patients.

METHODS

From 2005 to 2015, 497 locally advanced pancreatic cancer patients who received neoadjuvant or definitive chemoradiotherapy (CCRT) were included. Patients were divided according to the total dose (TD). Overall survival (OS), progression-free survival (PFS), local failure-free rate (LFFR), distant failure-free rate (DFFR), and toxicity rates were compared between <61Gy (n=345) and ≥61Gy groups (n=152). Additionally, propensity score matching was performed.

RESULTS

At a median follow-up of 19.3months (range, 4.8-128.5months), the 1-year OS, PFS, LFFR, and DFFR were significantly higher in the ≥61Gy group. After multivariate analysis, a TD of ≥61Gy remained a significant favorable factor for OS (p=0.019), PFS (p=0.001), LFFR (p=0.004), and DFFR (p=0.008). After propensity score matching, the ≥61Gy group still showed higher OS, PFS, and LFFR, but not DFFR (p=0.205). The acute and late toxicity rates showed no significant difference between the two groups.

CONCLUSION

Patients who received a higher RT dose showed not only improved PFS and LFFR, but also improved OS without an increase in severe toxicity. Dose-escalated CCRT can be a favorable treatment option in locally advanced pancreatic cancer patients.

A Comparison of Gastrointestinal Toxicities between Intensity-Modulated Radiotherapy and Three-Dimensional Conformal Radiotherapy for Pancreatic Cancer

Background/Aims

Concurrent chemoradiotherapy (CCRT) is considered the treatment option for locally advanced pancreatic cancer, but accompanying gastrointestinal toxicities are the most common complication. With the introduction of three-dimensional conformal radiotherapy (3-D CRT) and intensity-modulated radiotherapy (IMRT), CCRT-related adverse events are expected to diminish. Here, we evaluated the benefits of radiation modalities by comparing gastrointestinal toxicities between 3-D CRT and IMRT.

Methods

Patients who received CCRT between July 2010 and June 2012 in Severance Hospital, Yonsei University College of Medicine, were enrolled prospectively. The patients underwent upper endoscopy before and 1 month after CCRT.

Results

A total of 84 patients were enrolled during the study period. The radiotherapy modalities delivered included 3D-CRT (n=40) and IMRT (n=44). The median follow-up period from the start of CCRT was 10.6 months (range, 3.8 to 29.9 months). The symptoms of dyspepsia, nausea/vomiting, and diarrhea did not differ between the groups. Upper endoscopy revealed significantly more gastroduodenal ulcers in the 3-D CRT group (p=0.003). The modality of radiotherapy (3D-CRT; odds ratio [OR], 11.67; p=0.011) and tumor location (body of pancreas; OR, 11.06; p=0.009) were risk factors for gastrointestinal toxicities.

Conclusions

IMRT is associated with significantly fewer gastroduodenal injuries among patients treated with CCRT for pancreatic cancer.

Clinical usefulness of ¹⁸F-fluorodeoxyglucose-positron emission tomography in patients with locally advanced pancreatic cancer planned to undergo concurrent chemoradiation therapy

PURPOSE

To assess the role of coregistered (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting radiographically occult distant metastasis (DM) at staging in patients with locally advanced pancreatic cancer (LAPC) and to study whether FDG-PET parameters can predict relatively long-term survival in patients who are more likely to benefit from chemoradiation therapy (CRT).

METHODS AND MATERIALS

From our institutional database, we identified 388 LAPC patients with M0 on conventional computed tomography (CT) who were planned to undergo CRT. Coregistered FDG-PET staging was offered to all patients, and follow-up FDG-PET was used at the clinical discretion of the physician.

RESULTS

FDG-PET detected unsuspected CT-occult DM in 33% of all 388 patients and allowed them to receive systemic therapy immediately. The remaining 260 patients (PET-M0) underwent CRT selectively as an initial treatment. Early DM arose in 13.1% of 260 patients, and the 1-year estimated locoregional recurrence rate was 5.4%. Median overall survival (OS) and progression-free survival (PFS) were 14.6 and 9.3 months, respectively, at a median follow-up time of 32.3 months (range, 10-99.1 months). Patients with a baseline standardized uptake value (SUV) <3.5 and/or SUV decline ≥60% had significantly better OS and PFS than those having none, even after adjustment for all potential confounding variables (all P<.001).

CONCLUSIONS

FDG-PET can detect radiographically occult DM at staging in one-third of patients and spare them from the potentially toxic therapy. Additionally, FDG-PET parameters including baseline SUV and SUV changes may serve as useful clinical markers for predicting the prognosis in LAPC patients.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.

Definitive concurrent chemoradiotherapy in locally advanced pancreatic cancer

Purpose

Survival outcome of locally advanced pancreatic cancer has been poor and little is known about prognostic factors of the disease, especially in locally advanced cases treated with concurrent chemoradiation. This study was to analyze overall survival and prognostic factors of patients treated with concurrent chemoradiotherapy (CCRT) in locally advanced pancreatic cancer.

Materials and Methods

Medical records of 34 patients diagnosed with unresectable pancreatic cancer and treated with definitive CCRT, from December 2003 to December 2012, were reviewed. Median prescribed radiation dose was 50.4 Gy (range, 41.4 to 55.8 Gy), once daily, five times per week, 1.8 to 3 Gy per fraction.

Results

With a mean follow-up of 10 months (range, 0 to 49 months), median overall survival was 9 months. The 1- and 2-year survival rates were 40% and 10%, respectively. Median and mean time to progression were 5 and 7 months, respectively. Prognostic parameters related to overall survival were post-CCRT CA19-9 (p = 0.02), the Eastern Cooperative Oncology Group (ECOG) status (p < 0.01), and radiation dose (p = 0.04) according to univariate analysis. In multivariate analysis, post-CCRT CA19-9 value below 180 U/mL and ECOG status 0 or 1 were statistically significant independent prognostic factors associated with improved overall survival (p < 0.01 and p = 0.02, respectively).

Conclusion

Overall treatment results in locally advanced pancreatic cancer are relatively poor and few improvements have been accomplished in the past decades. Post-treatment CA19-9 below 180 U/mL and ECOG performance status 0 and 1 were significantly associated with an improved overall survival.

Phase II Trial of Cetuximab and Conformal Radiotherapy Only in Locally Advanced Pancreatic Cancer with Concurrent Tissue Sampling Feasibility Study

BACKGROUND

Preclinical data have indicated the anti-epidermal growth factor receptor (EGFR) agent cetuximab (Erbitux) as a radiosensitizer in pancreatic cancer, but this has not been specifically addressed in a clinical study. We report the results of an original study initiated in 2007, where cetuximab was tested with radiotherapy (RT) alone in locally advanced pancreatic cancer in a phase II trial (PACER).

METHODS

Patients (n = 21) received cetuximab loading dose (400 mg/m(2)) and weekly dose (250 mg/m(2)) during RT (50.4 Gy in 28 fractions). Toxicity and disease response end point data were prospectively assessed. A feasibility study of on-trial patient blood and skin sampling was incorporated.

RESULTS

Treatment was well tolerated, and toxicity was low; most patients (71%) experienced acute toxicities of grade 2 or less. Six months posttreatment, stable local disease was achieved in 90% of evaluable patients, but only 33% were free from metastatic progression. Median overall survival was 7.5 months, and actuarial survival was 33% at 1 year and 11% at 3 years, reflecting swift metastatic progression in some patients but good long-term control of localized disease in others. High-grade acneiform rash (P = .0027), posttreatment stable disease (P = .0059), and pretreatment cancer antigen 19.9 (CA19.9) level (P = .0042) associated with extended survival. Patient skin and blood samples yielded sufficient RNA and good quality protein, respectively.

CONCLUSIONS

The results indicate that cetuximab inhibits EGFR-mediated radioresistance to achieve excellent local control with minimal toxicity but does not sufficiently control metastatic progression in all patients. Translational studies of patient tissue samples may yield molecular information that may enable individual treatment response prediction.

Full-Dose Gemcitabine Is a More Effective Chemotherapeutic Agent Than 5-Fluorouracil for Concurrent Chemoradiotherapy as First-Line Treatment in Locally Advanced Pancreatic Cancer

<b><i>Objectives:</i></b> To compare the efficacy of full-dose gemcitabine-based concurrent chemoradiotherapy (FG-CCRT) and conventional 5-fluorouracil CCRT (5FU-CCRT) for locally advanced pancreatic cancer (LAPC). <b><i>Methods:</i></b> 109 LAPC cases treated with FG-CCRT (n = 89) or 5FU-CCRT (n = 20) were reviewed retrospectively. The FG-CCRT group was composed of a full-dose gemcitabine monotherapy (1,000 mg/m²) arm and a combination therapy with cisplatin (70 mg/m²) arm. The 5FU-CCRT group used a radiosensitizing dose of 5-FU (500 mg/m²) plus leucovorin (20 mg/m²). Concurrent radiotherapy was targeted at the tumor with a 5-mm margin without lymph node irradiation. <b><i>Results:</i></b> Objective response rate (ORR) and disease control rate (DCR) was significantly higher in the FG-CCRT group (ORR: 32.6 vs. 5%, p = 0.013; DCR: 79.8 vs. 50.0%, p = 0.006). FG-CCRT showed remarkable superiority to 5FU-CCRT for suppressing distant metastasis (18.0 vs. 45.0%, p = 0.017). Neutropenia (34.8 vs. 10%, p = 0.032) and thrombocytopenia (21.3 vs. 0.0%, p = 0.021) were more frequent in the FG-CCRT group as originally expected. When dividing the FG-CCRT group to gemcitabine monotherapy (GEM) and gemcitabine plus cisplatin, toxicities of the GEM subgroup were not different than those of the 5FU-CCRT group. <b><i>Conclusion:</i></b> FG-CCRT, especially full-dose gemcitabine monotherapy-based CCRT was more effective for the initial control of LAPC than 5FU-CCRT, and also relatively safe.