Analysis of local control in patients receiving IMRT for resected pancreatic cancers

Para-aortic lymph node metastasis in lower Thoracic Esophageal Squamous Cell Carcinoma after Radical Esophagectomy: a CT-based atlas and its clinical implications for Adjuvant Radiotherapy

Background: Our previous work showed that para-aortic lymph node (PALN) metastasis was the major failure pattern in lower thoracic esophageal squamous cell carcinoma (LTESCC) patients who presented abdominal LN failure after curative surgery. We thereby aim to generate a computerized tomography (CT)-based documentation of PALNs and to propose a clinical target volume (CTV) for this region. Methods: Sixty-five patients were enrolled. The epicentre of each PALN was drawn onto an axial CT image of a standard patient with reference to the surrounding anatomical landmarks. A CTV for PALN was generated based on the final result of node distribution, and was evaluated for dosimetric performance in three simulated patients. Results: All the studied 248 LNs were below the level of 1.0 cm above the celiac artery (CA), and 94.76% were above the bottom of vertebra L3. Horizontally, 93.33% of the LNs in the celiac level were located within an expansion of 1.5 cm on the CA, and 94.12% of the LNs in the superior mesenteric artery (SMA) level were within 1.5 cm on the left side of the SMA. Below the SMA, all the LNs were behind the left renal vein, left to the right border of the inferior vena cava, and 98.51% of the LNs were medial to the lateral surface of the left psoas major. The proposed CTV could cover 92.74% of the LNs and was dosimetrically feasible. Conclusions: The proposed CTV is the first one to focus on the high-risk area of abdominal failure in LTESCC patients after surgery and can serve as a reference in the adjuvant radiotherapy for LTESCC patients.

Inhibition of focal adhesion kinase enhances antitumor response of radiation therapy in pancreatic cancer through CD8+ T cells

Objective:

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy, due in large part to its resistance to conventional therapies, including radiotherapy (RT). Despite RT exerting a modest antitumor response, it has also been shown to promote an immunosuppressive tumor microenvironment. Previous studies demonstrated that focal adhesion kinase inhibitors (FAKi) in clinical development inhibit the infiltration of suppressive myeloid cells and T regulatory (T regs) cells, and subsequently enhance effector T cell infiltration. FAK inhibitors in clinical development have not been investigated in combination with RT in preclinical murine models or clinical studies. Thus, we investigated the impact of FAK inhibition on RT, its potential as an RT sensitizer and immunomodulator in a murine model of PDAC.

Methods:

We used a syngeneic orthotopic murine model to study the effect of FAKi on hypofractionated RT.

Results:

In this study we showed that IN10018, a small molecular FAKi, enhanced antitumor response to RT. Antitumor activity of the combination of FAKi and RT is T cell dependent. FAKi in combination with RT enhanced CD8+ T cell infiltration significantly in comparison to the radiation or FAKi treatment alone (P < 0.05). FAKi in combination with radiation inhibited the infiltration of granulocytes but enhanced the infiltration of macrophages and T regs in comparison with the radiation or FAKi treatment alone (P < 0.01).

Conclusions:

These results support the clinical development of FAKi as a radiosensitizer for PDAC and combining FAKi with RT to prime the tumor microenvironment of PDAC for immunotherapy.

Evaluating the Impact of ESPAC-1 on Shifting the Paradigm of Pancreatic Cancer Treatment

BACKGROUND

In 2004, the European Study Group for Pancreatic Cancer (ESPAC)-1 long-term data concluded that adjuvant chemotherapy provided a survival benefit for patients with pancreatic ductal adenocarcinoma (PDAC), whereas adjuvant chemoradiation was associated with worse overall survival. In this study, we investigated how long it took for US practice patterns to change following this trial.

METHODS

The National Cancer Database was used to identify patients with stage I-III PDAC who underwent R0 or R1 resection followed by adjuvant chemotherapy or chemoradiation between 1998 and 2015. A multivariate analysis was performed to determine predictors of receiving adjuvant chemoradiation in the post-ESPAC-1 era.

RESULTS

Between 1998 and 2015, adjuvant chemotherapy use increased from 2.9% to 51.6%, whereas adjuvant chemoradiation decreased from 49.5% to 22.9%. In 2010, adjuvant chemotherapy utilization surpassed that of chemoradiation. For patients diagnosed in the post-ESPAC-1 era, adjuvant chemotherapy (n = 7733) and chemoradiation (n = 6969) groups were compared. Patients who underwent adjuvant chemoradiation were younger, had private insurance, underwent surgery at nonacademic centers, and had more pathologically advanced cancers (all P < 0.01). After 2010, R1 resection was the strongest independent predictor of adjuvant chemoradiation use by multivariate analysis (OR 2.05, CI 1.8-2.3, P < 0.01).

CONCLUSIONS

Adjuvant chemotherapy use exceeded that of adjuvant chemoradiation 6 y after the final publication of ESPAC-1 in 2004, highlighting the challenges of disseminating and adopting clinical data. After 2010, R1 disease was the most significant predictor of receiving adjuvant chemoradiation. Prospective studies are underway to definitively address the role of adjuvant chemoradiation in PDAC.

Proton beam radiotherapy for pancreas cancer

Pancreatic carcinoma is a challenging malignancy to manage with a very poor prognosis. Despite continued difficulties in its management, there have been incremental improvements in outcomes over the past several decades. Achieving the best oncologic outcomes requires a multimodality approach including surgery, chemotherapy, and radiotherapy. Proton radiotherapy enables the delivery of high-dose radiotherapy to the tumor or resection bed while sparing nearby critical organs. Due to their unique physical properties, protons can deliver radiotherapy dose distributions that are not achievable with photons (X-rays) even with advanced photon delivery techniques (e.g., intensity-modulated radiotherapy). Improved dose distributions can lead to reduced treatment toxicity and enable treatment intensification. As better chemotherapy regimens lead to better systemic disease control, it will become increasingly important that local-regional control is achieved. This will in part be accomplished by combining better radiotherapy with more active chemotherapies. Proton radiotherapy provides an excellent means for achieving this.

Irreversible electroporation and adjuvant chemoradiotherapy for locally advanced pancreatic carcinoma

CONTEXT

The safety and efficacy of irreversible electroporation (IRE) for locally advanced pancreatic carcinoma (LAPC) are well established. However, whether adjuvant chemoradiotherapy after IRE increases, the survival rate remains unknown. Therefore, this study evaluated the effect of chemoradiotherapy combined with IRE in patients with LAPC.

SUBJECTS AND METHODS

We retrospectively analyzed 42 patients with LAPC between July 2015 and December 2016 at PLA General Hospital treated with IRE or IRE combined with radiation and/or chemotherapy. These patients were divided into the IRE group and the combined-therapy group. All patients underwent computed tomography (CT), magnetic resonance imaging, and positron-emission tomography-CT and no signs of metastases were found. The prognosis of these patients was observed.

RESULTS

The times after operation and after diagnosis in the combined-therapy group (304.20 ± 118.54) and (334.40 ± 114.07) days, respectively, were better those than in the IRE group (214.36 ± 95.68) and (244.68 ± 110.61) days, respectively. Moreover, patients in the combined-therapy group had a significantly better survival rate than the IRE group (80 vs. 45.45%, P < 0.05).

CONCLUSIONS

IRE combined with radiotherapy or chemotherapy was superior to IRE alone for the treatment of LAPC, as it prolonged the survival time and improved the survival rate, making it worthy of wide dissemination and clinical application.

Duration of chemotherapy prior to chemoradiation affects survival outcomes for resected stage I-II or unresected stage III pancreatic cancer

Background

For resected early stage pancreatic cancer, RTOG 9704 evaluated the outcome of 3 weeks of postoperative chemotherapy (C) followed by chemoradiation (CRT) and further C. For unresectable locally advanced pancreatic cancer, a recent literature review of prospective studies showed that the duration of induction C prior to CRT can impact survival. However, the ideal duration of C prior to CRT remains unclear for these patient cohorts. This National Cancer Database (NCDB) study was performed to compare the outcome of various durations of C prior to CRT.

Methods

The NCDB was queried for resected primary stage I‐II, cT1‐3N0‐1M0, and unresected stage III, cT4N0‐1M0 pancreatic adenocarcinoma treated with C + CRT (2004‐2015). Cohorts I‐II and III included stage I‐II and stage III cases, respectively. Patients were stratified by short (short C) and long duration (long C) of chemotherapy based on their median durations. Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan‐Meier analysis, multivariable Cox proportional hazards method, and propensity score matching were used.

Results

Among 1577 patients, cohort I‐II had 839 patients and cohort III had 738 patients. The longer duration of chemotherapy prior to CRT showed improved OS in the multivariate analysis in both cohort I‐II (hazards ratio [HR] 0.72, P < 0.001) and cohort III (HR 0.83, P = 0.03). Using 1:1 propensity score matching, 610 patients for cohort I‐II and 542 patients for cohort III were matched. After matching, long C remained statistically significant for improved OS compared with short C in both cohort I‐II (median OS 26.1 vs 21.9 months; P = 0.003) and cohort III (median OS 16.7 vs 14.2; P = 0.02).

Conclusion

Our NCDB study using propensity score‐matched analysis showed a survival benefit for using the longer duration of chemotherapy compared to the shorter duration for both resected stage I‐II and unresected stage III pancreatic cancer.

Adjuvant chemoradiation in pancreatic cancer: impact of radiotherapy dose on survival

BACKGROUND

To evaluate the impact of radiation dose on overall survival (OS) in patients treated with adjuvant chemoradiation (CRT) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

A multicenter retrospective analysis on 514 patients with PDAC (T1-4; N0-1; M0) treated with surgical resection with macroscopically negative margins (R0-1) followed by adjuvant CRT was performed. Patients were stratified into 4 groups based on radiotherapy doses (group 1: < 45 Gy, group 2: ≥ 45 and < 50 Gy, group 3: ≥ 50 and < 55 Gy, group 4: ≥ 55 Gy). Adjuvant chemotherapy was prescribed to 141 patients. Survival functions were plotted using the Kaplan-Meier method and compared through the log-rank test.

RESULTS

Median follow-up was 35 months (range: 3-120 months). At univariate analysis, a worse OS was recorded in patients with higher preoperative Ca 19.9 levels (≥ 90 U/ml; p < 0.001), higher tumor grade (G3-4, p = 0.004), R1 resection (p = 0.004), higher pT stage (pT3-4, p = 0.002) and positive nodes (p < 0.001). Furthermore, patients receiving increasing doses of CRT showed a significantly improved OS. In groups 1, 2, 3, and 4, median OS was 13.0 months, 21.0 months, 22.0 months, and 28.0 months, respectively (p = 0.004). The significant impact of higher dose was confirmed by multivariate analysis.

CONCLUSIONS

Increasing doses of CRT seems to favorably impact on OS in adjuvant setting. The conflicting results of randomized trials on adjuvant CRT in PDAC could be due to < 45 Gy dose generally used.

Adjuvant chemotherapy followed by concurrent chemoradiation is associated with improved survival for resected stage I-II pancreatic cancer

Background

This National Cancer Database (NCDB) analysis evaluates the clinical outcomes of postoperative chemotherapy followed by concurrent chemoradiation (C + CRT) compared to concurrent chemoradiation (CRT) alone or adjuvant chemotherapy alone (C) for resected pancreatic cancer.

Methods

The NCDB was queried for primary stage I‐II, cT1‐3N0‐1M0, resected pancreatic adenocarcinoma treated with adjuvant C, CRT, or C + CRT (2004‐2015). Patients treated with C + CRT were compared with those treated with C (cohort C) and CRT (cohort CRT). Baseline patient, tumor, and treatment characteristics were examined. Kaplan‐Meier analysis, multivariable Cox proportional hazards method, forest plot, and propensity score matching were used.

Results

Among 5667 patients, median follow‐up was 34.7, 45.2, and 39.7 months for the C, CRT, and C + CRT cohorts, respectively. By multivariable analysis for all patients, C and CRT had worse OS compared to C + CRT. Treatment interactions were seen among pathologically node‐positive disease. C + CRT was favored in 1‐3 and 4+ positive lymph node diseases when compared to C or CRT alone, but none of the treatment options were significantly favored in node negative disease. Using propensity score matching, 2152 patients for cohort C and 1774 patients for cohort CRT were matched. C + CRT remained significant for improved OS for both cohort C (median OS 23.3 vs 20.0 months) and cohort CRT (median OS 23.4 vs 20.8 months).

Conclusion

This NCDB study using propensity score matched analysis suggests an OS benefit for C + CRT compared to C or CRT alone following surgical resection of pancreatic cancer, particularly for patients with pathologically positive lymph nodes.

Effects of chemoradiotherapy and chemotherapy on survival of patients with locally advanced pancreatic cancer: A meta-analysis of randomized controlled trials

To comparatively evaluate chemoradiotherapy (CRT) and chemotherapy (CT) for the treatment of locally advanced pancreatic cancer (LAPC) by meta-analysis.A literature search was performed until August 2016 to identify comparative studies assessing survival rates and complications. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined with the fixed or random effects model.Five randomized controlled trials (RCTs) met the defined inclusion criteria. A total of 593 patients were included, with 295 and 298 treated with CRT and CT, respectively. Overall survival showed no statistically significant difference in patients treated with CRT and CT at 6, 12, 18, and 24 months (respectively: OR = 1.13, 95% CI: 0.60-2.17; OR = 1.15, 95% CI: 0.53-2.52; OR = 1.13, 95% CI: 0.43-2.95; OR = 1.07, 95% CI: 0.67-1.72). Meanwhile, CRT had higher rates of grade 3 to 4 adverse events (nausea and vomiting, OR = 2.74, 95% CI: 1.36-5.52; diarrhea, OR = 4.28, 95% CI: 1.16-15.71).The data are not sufficient to change from CT to CRT in the treatment of patients with LAPC and thus clinical discretion is required until more data is accumulated.

Adjuvant therapeutic strategies for resectable pancreatic adenocarcinoma

Of all patients diagnosed with pancreatic adenocarcinoma, only 15-20% present with resectable disease. Despite curative-intent resection, the prognosis remains poor with the majority of patients recurring, prompting the need for adjuvant therapy. Historical data support the use of adjuvant 5-fluorouracil (5-FU) or gemcitabine, but recent data suggest either gemcitabine plus capecitabine or modified FOLFIRINOX can improve overall survival when compared to gemcitabine alone. The use of adjuvant chemoradiation therapy remains controversial, primarily due to limitations in study design and mixed results of historical trials. The ongoing Radiation Therapy Oncology Group (RTOG)-0848 trial hopes to further define the role of adjuvant chemoradiation therapy. Intraoperative radiation therapy (IORT) and adjuvant immunotherapy represent additional possibilities to improve outcomes, but evidence supporting their use is limited. This article reviews adjuvant therapeutic strategies for resectable pancreatic adenocarcinoma, including chemotherapy, chemoradiation therapy, IORT and immunotherapy.

Redefining the Positive Margin in Pancreatic Cancer: Impact on Patterns of Failure, Long-Term Survival and Adjuvant Therapy

PURPOSE

There is debate regarding the definition and clinical significance of margin clearance in pancreatic ductal adenocarcinoma (PDA). A comprehensive archival analysis of surgical resection margins was performed to determine the effect on locoregional recurrence and survival, and the impact of adjuvant therapy in PDA.

METHODS

We identified 105 patients with resected PDA. Pancreatic, anterior, bile duct, and posterior surgical resection margins (PM; posterior surface, uncinate and vascular groove) were identified. Three pathologists reviewed all archival surgical specimens and recategorized each margin as tumor at ink/transected, <0.5, 0.5-1, >1-2, or >2 mm from the inked surface. The impact of these and other clinical variables was assessed on local control, disease-free survival (DFS), and overall survival (OS).

RESULTS

Among all margins, PM clearance up to 2 mm was prognostic of DFS (p = 0.01) and OS (p = 0.01). Dichotomizing the PM at 2 mm revealed it to be an independent predictor of local recurrence-free survival [hazard ratio HR] 0.20, 95% confidence interval [CI] 0.048-0.881, p = 0.033), DFS (HR 0.46, 95% CI 0.22-0.96, p = 0.03), and OS (HR 0.31, 95% CI 0.14-0.74, p = 0.008). A margin status of >2 mm was also prognostic of OS in patients who received adjuvant chemotherapy (HR 0.31, 95% CI 0.11-0.89, p = 0.03), however this difference was mitigated in patients receiving adjuvant chemoradiotherapy (HR 0.40, 95% CI 0.10-1.58, p = 0.19).

CONCLUSION

These data highlight the clinical significance of the PM and the lack of significance of other resection margins. Clearance in excess of 2 mm should be considered to improve long-term clinical outcomes. The use of adjuvant radiotherapy should be strongly considered in patients with PMs <2 mm.

ACR Appropriateness Criteria® Resectable Pancreatic Cancer

Management of resectable pancreatic adenocarcinoma continues to present a challenge due to a paucity of high-quality randomized studies. Administration of adjuvant chemotherapy is widely accepted due to the high risk of systemic spread associated with pancreatic adenocarcinoma, but the role of radiation therapy is less clear. This paper reviews literature associated with resectable pancreatic cancer to include prognostic factors to aid in the selection of patients appropriate for adjuvant therapies. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Feasibility of automated 3-dimensional magnetic resonance imaging pancreas segmentation

Purpose

With the advent of magnetic resonance imaging (MRI) guided radiation therapy, internal organ motion can be imaged simultaneously during treatment. In this study, we evaluate the feasibility of pancreas MRI segmentation using state-of-the-art segmentation methods.

Methods and materials

T2-weighted half-Fourier acquisition single-shot turbo spin-echo and T1 weighted volumetric interpolated breath-hold examination images were acquired on 3 patients and 2 healthy volunteers for a total of 12 imaging volumes. A novel dictionary learning (DL) method was used to segment the pancreas and compared to t mean-shift merging, distance regularized level set, and graph cuts, and the segmentation results were compared with manual contours using Dice's index, Hausdorff distance, and shift of the center of the organ (SHIFT).

Results

All volumetric interpolated breath-hold examination images were successfully segmented by at least 1 of the autosegmentation method with Dice's index >0.83 and SHIFT ≤2 mm using the best automated segmentation method. The automated segmentation error of half-Fourier acquisition single-shot turbo spin-echo images was significantly greater. DL is statistically superior to the other methods in Dice’s overlapping index. For the Hausdorff distance and SHIFT measurement, distance regularized level set and DL performed slightly superior to the graph cuts method, and substantially superior to mean-shift merging. DL required least human supervision and was faster to compute.

Conclusions

Our study demonstrated potential feasibility of automated segmentation of the pancreas on MRI scans with minimal human supervision at the beginning of imaging acquisition. The achieved accuracy is promising for organ localization.

Addition of radiotherapy to adjuvant chemotherapy is associated with improved overall survival in resected pancreatic adenocarcinoma: An analysis of the National Cancer Data Base

BACKGROUND

The optimal treatment for resected pancreatic cancer is controversial because direct comparisons of adjuvant chemotherapy (CT) alone and chemotherapy and radiotherapy (CRT) are limited. This study assessed outcomes of CT versus CRT in a national cohort to provide a modern estimate of comparative effectiveness.

METHODS

Patients with pT1-3N0-1M0 pancreatic adenocarcinoma after pancreatectomy were identified in the National Cancer Data Base. Overall survival (OS) was compared for CT and CRT groups with Cox regression and propensity score matching. Subset analyses by clinicopathologic characteristics were performed.

RESULTS

This study identified 6165 patients treated with CT (n = 2334 or 38%) or CRT (n = 3831 or 62%). Most were classified as pT3 (72%), pN1 (67%), and status-post R0 resection (84%). For CRT patients, the median radiotherapy dose was 50.4 Gy. Compared with CT, CRT was associated with improved OS in a univariate analysis (median, 20.0 vs 22.3 months; at 5 years, 16.5% vs 19.6%; P < .001) and a multivariate analysis (hazard ratio [HR], 0.893; 95% confidence interval [CI], 0.837-0.953; P = .001). CRT remained associated with improved OS after propensity score matching (HR, 0.851; 95% CI, 0.793-0.913; P < .001). Subset analyses showed that CRT was associated with improved OS among patients with pT3 (HR, 0.892; 95% CI, 0.828-0.962; P = .003) or pN1 disease (HR, 0.856; 95% CI, 0.793-0.924; P < .001) and both R0 resection (HR, 0.901; 95% CI, 0.839-0.969; P = .005) and R1 resection (HR, 0.842; 95% CI, 0.722-0.983; P = .030).

CONCLUSIONS

CRT was independently associated with improved OS after the resection of pancreatic adenocarcinoma in a large national cohort and particularly among patients with R1 resection and pN1 disease. Well-designed randomized comparisons of CRT and CT are urgently needed.

Adjuvant radiation therapy for pancreatic cancer: a review of the old and the new

Surgery represents the only potential curative treatment option for patients diagnosed with pancreatic adenocarcinoma. Despite aggressive surgical management for patients deemed to be resectable, rates of local recurrence and/or distant metastases remain high, resulting in poor long-term outcomes. In an effort to reduce recurrence rates and improve survival for patients having undergone resection, adjuvant therapies (ATs) including chemotherapy and chemoradiation therapy (CRT) have been explored. While adjuvant chemotherapy has been shown to consistently improve outcomes, the data regarding adjuvant radiation therapy (RT) is mixed. Although the ability of radiation to improve local control has been demonstrated, it has not always led to improved survival outcomes for patients. Early trials are flawed in their utilization of sub-optimal radiation techniques, limiting their generalizability. Recent and ongoing trials incorporate more optimized RT approaches and seek to clarify its role in treatment strategies. At the same time novel radiation techniques such as intensity modulated RT (IMRT) and stereotactic body RT (SBRT) are under active investigation. It is hoped that these efforts will lead to improved disease-related outcomes while reducing toxicity rates.

Evaluation of prognostic factors and survival results in pancreatic carcinomas in Turkey

BACKGROUND

The goal of this retrospective study was to evaluate patient characteristics, treatment modalities and prognostic factors in Turkish patients with pancreatic cancer.

MATERIALS AND METHODS

Between January 1997 and December 2012, 64 patients who presented to the Department of Radiation Oncology, Karadeniz Technical University, Faculty of Medicine with a diagnosis of pancreatic cancer were evaluated. The E/K ratio of the cases was 2.4/1 and the median age was 59.6 (32-80) years, respectively. Some 11 cases (18%) were stage 1, 21 (34.4%) were stage 2, 10 (16.4%) were stage 3, and 19 (31.1%) were metastatic.

RESULTS

The mean follow-up time was 15.7 months (0.7-117.5) and loco-regional recurrence was noted in 11 (40.7%) who underwent surgery while metastases were observed in 41 patients (66.1%). The median overall survival (OS) was 11.2 months and the 1, 3 and 5-year OS rates were 41.7%, 9.9% and 7.9% respectively. The median disease-free survival (DFS) was 5.2 month and the1, 2 and 5 year DFS were 22.6%, 7.6% and 3.8% respectively. On univariate analysis, prognostic factors affecting OS included status of the operation (p<0.001), tumor stage (p=0.008), ECOG performance status (p=0.005) and CEA level (p=0.017).On multivariate analysis, prognostic factors affecting survival included status of the operation (p=0.033) and age (p= 0.023).

CONCLUSIONS

In the current study, age and operation status were independent prognostic factors for overall survival with pancreatic patients. Thus, the patients early diagnosis and treatment ars essential. However, prospective studies with more patients are needed for confirmation.

Utilization of intensity-modulated radiation therapy and image-guided radiation therapy in pancreatic cancer: is it beneficial?

The recent development of intensity-modulated radiation therapy (IMRT) and improvements in image-guided radiotherapy (IGRT) have provided considerable advances in the utilization of radiation therapy (RT) for the management of pancreatic cancer. IGRT allows for the reduction of treatment volumes, potentially less chance of a marginal miss, and quality assurance of gastrointestinal filling, while IMRT has been shown to reduce both sudden and late side effects compared with 3-dimensional conformal RT. Here, we review published data and provide essential recommendations on the utilization of IMRT and IGRT for the management of patients with pancreatic cancer.

S-1 plus gemcitabine chemotherapy followed by concurrent radiotherapy and maintenance therapy with S-1 for unresectable pancreatic cancer

AIM: To investigate the feasibility and efficacy of the combination of S-1 with gemcitabine followed by oral S-1 with concurrent radiotherapy (intensity modulated radiotherapy, IMRT) and maintenance therapy with S-1 for locally advanced pancreatic cancer.

METHODS: Subjects selected in the study were patients who had unresectable and locally advanced pancreatic cancer without distant metastases, adequate organ and marrow functions, an Eastern Cooperative Oncology Group performance status of 0-1 and no prior anticancer therapy. Initially the subjects received two cycles of chemotherapy, oral administration of S-1 40 mg/m² twice daily from day 1 to day 14 of a 21-d cycle, with 30-min intravenous infusions of gemcitabine 1000 mg/m² on day 1 and day 8. Two weeks after the completion of chemotherapy, S-1 was administered orally with concurrent IMRT. Oral S-1 was administered at a dose of 80 mg/m² per day twice daily from day 1 to day 14 and from day 22 to day 35. Radiation was concurrently delivered at a dose of 50.4 Gy (1.8 Gy/d, 5 times per week, 28 fractions). One month after the completion of chemotherapy and radiotherapy, S-1 was administered orally at a dose of 80 mg/m² per day twice daily for 14 d, followed by a 14-d rest period. This cycle was repeated as maintenance therapy, until unacceptable toxicity occurred or the disease worsened. Thirty-two patients were involved in this study. The median follow-up was 15.6 mo (range: 8.6-32.3 mo).

RESULTS: Thirty-two patients completed the scheduled course of chemotherapy, while 30 patients (93.8%) received chemoradiotherapy with two patients ceasing to continue with radiotherapy. The major toxic effects were nausea and leukopenia. There was no grade 4 toxicity or treatment-related death. According to the Response Evaluation Criteria in Solid Tumors criteria, the objective tumor response was partial response in 17 (53.1%) patients, stable disease in 9 (28.1%), and progressive disease in 6 (18.8%). The median overall survival and median progression-free survival were 15.2 mo and 9.3 mo, respectively. The survival rates at 1 year and 2 years were 75% and 34.4%, respectively.

CONCLUSION: The combination of S-1 with gemcitabine followed by oral S-1 with IMRT and maintenance therapy with S-1 alone in patients with locally advanced pancreatic cancer may be considered a well-tolerated, promising treatment regimen.

Feasibility of automated pancreas segmentation based on dynamic MRI

OBJECTIVE

MRI-guided radiotherapy is particularly attractive for abdominal targets with low CT contrast. To fully utilize this modality for pancreas tracking, automated segmentation tools are needed. A hybrid gradient, region growth and shape constraint (hGReS) method to segment two-dimensional (2D) upper abdominal dynamic MRI (dMRI) is developed for this purpose.

METHODS

2D coronal dynamic MR images of two healthy volunteers were acquired with a frame rate of 5 frames per second. The regions of interest (ROIs) included the liver, pancreas and stomach. The first frame was used as the source where the centres of the ROIs were manually annotated. These centre locations were propagated to the next dMRI frame. Four-neighborhood region transfer growth was performed from these initial seeds before refinement using shape constraints. RESULTS from hGReS and two other automated segmentation methods using integrated edge detection and region growth (IER) and level set, respectively, were compared with manual contours using Dice's index (DI).

RESULTS

For the first patient, the hGReS resulted in the organ segmentation accuracy as a measure by the DI (0.77) for the pancreas, superior to the level set method (0.72) and IER (0.71). The hGReS was shown to be reproducible on the second subject, achieving a DI of 0.82, 0.92 and 0.93 for the pancreas, stomach and liver, respectively. Motion trajectories derived from the hGReS were highly correlated to respiratory motion.

CONCLUSION

We have shown the feasibility of automated segmentation of the pancreas anatomy on dMRI.

ADVANCES IN KNOWLEDGE

Using the hybrid method improves segmentation robustness of low-contrast images.

Role of chemoradiotherapy in the adjuvant and neoadjuvant settings for resectable pancreatic cancer

Pancreatic cancer is the 10th most commonly diagnosed malignancy in the USA and the fourth most common cause of cancer-related death. Worldwide, the mortality incidence ratio approaches 98%. Although only 15-20% of patients present with resectable disease, there is international consensus that complete surgical resection (R0, i.e. grossly and microscopically negative margins) is a vital part of any curative treatment paradigm. Despite advances in surgical technique, peri-operative care, chemotherapy and radiation delivery techniques over the past two decades, 5 year overall survival rates for resected pancreatic cancer with modern therapies remain around 20-25%. There is level I evidence for adjuvant chemotherapy in fully resected pancreatic cancer, but randomised trials examining the role of adjuvant chemoradiotherapy to date do not provide clear support for radiation therapy in this setting. In addition, efforts to increase the proportion of long-term survivors have recently centred on increasing the resectability of locoregional disease by incorporating neoadjuvant treatment before definitive surgery. Post-hoc analysis of randomised data as well as retrospective reviews have shown that there are several independent prognostic factors that may have considerable impact on survival outcomes, complicating interpretation and comparison of historical data. There is considerable interest in adjuvant and neoadjuvant therapy, but there is significant controversy as to whether radiation is of value, especially in the adjuvant context. Herein, we explore the sources of those controversies.

Intensity modulated radiotherapy of upper abdominal malignancies: dosimetric comparison with 3D conformal radiotherapy and acute toxicity

Background

The goal of this study was to assess a possible dosimetric advantage of intensity modulated radiotherapy (IMRT) of upper abdominal malignancies compared to three-dimensional conformal radiotherapy (3DCRT), and to assess the impact of IMRT on acute toxicity.

Methods

Thirty-one unselected consecutive patients with upper abdominal malignancies were treated with definitive (n =16) or postoperative (n =15) IMRT. Twenty-one patients (67.7%) received concomitant chemotherapy. 3DCRT plans were generated for comparison, and analysis of variance (ANOVA) for repeated measurements was used to test for significant difference of dosimetric parameters. Acute toxicity was assessed weekly using the Common Terminology Criteria for Adverse Events (CTCAE) grading scale.

Results

IMRT plans showed a small but statistically significant improvement of the conformity index compared to 3DCRT plans (difference (95% confidence interval), -0.06 (−0.109 to-0.005); p = 0.03). The homogeneity index was not significantly improved (p = 0.10). A significantly reduced high dose volume on cost of a significantly increased low dose volume was observed for the kidneys. The acute toxicity appeared to be less than commonly reported for corresponding patients treated with 3DCRT. No patient developed grade 3 or 4 non-hematological acute toxicity, and the most common grade 2 toxicity was vomiting (9.7%).

Conclusions

IMRT offers the potential of a clinically relevant dosimetric advantage compared to 3DCRT in terms of a reduced acute toxicity. Further optimization of the radiotherapy technique and more clinical trials are required before IMRT is routinely used for upper abdominal malignancies.

Recent progress in pancreatic cancer

Pancreatic cancer is currently one of the deadliest of the solid malignancies. However, surgery to resect neoplasms of the pancreas is safer and less invasive than ever, novel drug combinations have been shown to improve survival, advances in radiation therapy have resulted in less toxicity, and enormous strides have been made in the understanding of the fundamental genetics of pancreatic cancer. These advances provide hope but they also increase the complexity of caring for patients. It is clear that multidisciplinary care that provides comprehensive and coordinated evaluation and treatment is the most effective way to manage patients with pancreatic cancer.

Postoperative radiotherapy in periampullary cancers: a brief review

BACKGROUND

The treatment of periampullary cancers is complex and challenging. Adjuvant therapy for resected periampullary and pancreatic cancers has been the subject of intense clinical investigations for several decades. Periampullary cancer management has often been clubbed with pancreatic cancers.

DISCUSSION

Following surgery, adjuvant chemoradiotherapy has been widely accepted as standard of care in the USA, although different prospective and retrospective studies have shown conflicting results. Controversy regarding the effectiveness of chemoradiotherapy exists in the literature, both in terms of survival as well as toxicity. However, conventional postoperative radiotherapy practice needs to be reviewed in view of changes and developments in radiation techniques in the last decade. In this article, we review the management of periampullary cancers with special emphasis on the adjuvant postoperative radiotherapy.

Intensity modulated radiotherapy as neoadjuvant chemoradiation for the treatment of patients with locally advanced pancreatic cancer. Outcome analysis and comparison with a 3D-treated patient cohort

BACKGROUND

To evaluate outcome after intensity modulated radiotherapy (IMRT) compared to 3D conformal radiotherapy (3D-RT) as neoadjuvant treatment in patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

In total, 57 patients with LAPC were treated with IMRT and chemotherapy. A median total dose of 45 Gy to the PTV_baseplan and 54 Gy to the PTV_boost in single doses of 1.8 Gy for the PTV_baseplan and median single doses of 2.2 Gy in the PTV_boost were applied. Outcomes were evaluated and compared to a large cohort of patients treated with 3D-RT.

RESULTS

Overall treatment was well tolerated in all patients and IMRT could be completed without interruptions. Median overall survival was 11 months (range 5-37.5 months). Actuarial overall survival at 12 and 24 months was 36 % and 8 %, respectively. A significant impact on overall survival could only be observed for a decrease in CA 19-9 during treatment, patients with less pre-treatment CA 19-9 than the median, as well as weight loss during treatment. Local progression-free survival was 79 % after 6 months, 39 % after 12 months, and 13 % after 24 months. No factors significantly influencing local progression-free survival could be identified. There was no difference in overall and progression-free survival between 3D-RT and IMRT. Secondary resectability was similar in both groups (26 % vs. 28 %). Toxicity was comparable and consisted mainly of hematological toxicity due to chemotherapy.

CONCLUSION

IMRT leads to a comparable outcome compared to 3D-RT in patients with LAPC. In the future, the improved dose distribution, as well as advances in image-guided radiotherapy (IGRT) techniques, may improve the use of IMRT in local dose escalation strategies to potentially improve outcome.

Recent progress in pancreatic cancer

Pancreatic cancer is currently one of the deadliest of the solid malignancies. However, surgery to resect neoplasms of the pancreas is safer and less invasive than ever, novel drug combinations have been shown to improve survival, advances in radiation therapy have resulted in less toxicity, and enormous strides have been made in the understanding of the fundamental genetics of pancreatic cancer. These advances provide hope but they also increase the complexity of caring for patients. It is clear that multidisciplinary care that provides comprehensive and coordinated evaluation and treatment is the most effective way to manage patients with pancreatic cancer.

Overview of whole body gamma knife for locally advanced pancreatic cancer

Pancreatic cancer is a disease that seriously threatens the health of human beings. The treatment options currently available for pancreatic cancer are still limited. In this article, we describe the principle of whole body gamma knife and SBRT (a treatment similar to whole body gamma knife) for the treatment of advanced pancreatic cancer. By improving the absorbed dose in the lesion, whole body gamma knife can control tumor progression and improve survival in patients with pancreatic cancer with low side effects. Despite that controversy still exists, the advantages of SBRT in the treatment of pancreatic cancer have been gradually recognized in foreign countries.