5-fluorouracil–based chemoradiation in unresectable pancreatic carcinoma: phase I-II dose-escalation study

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.

Association of radiotherapy with favorable prognosis in daily clinical practice for treatment of locally advanced and metastatic pancreatic cancer

BACKGROUND AND AIM

Radiotherapy (RT) with or without chemotherapy is currently used in definitive therapy for advanced pancreatic cancer. We sought to evaluate the prognostic significance, pattern of care, and use of RT in locally advanced and metastatic pancreatic cancer.

METHODS

Between 2002 and 2011, patients with invasive pancreatic carcinoma and prior exposure to systemic chemotherapy were included. We used Cox regression model and propensity score matching for prognostic analyses and logistic regression for analyzing the factors impacting the use of RT.

RESULTS

We identified 217 pancreatic cancer patients (74 with unresectable stage II or III and 143 with stage IV). Of all patients, 90.8% had adenocarcinoma, and only 19.2% (42/217) received RT with doses ranging from 50 to 55 Gy in 25 to 28 fractions using modern RT techniques. Logistic regression showed stage (P < 0.001) and initial CA 19-9 level (P = 0.026) were significantly predictive of the choice of RT as a first-line treatment, whereas the second-line use of RT was associated with the response to first-line chemotherapy and longer progression-free survival. Patients with RT had a better median survival than those without it (14.6 vs 8.1 months, P < 0.001). In the multivariate analysis and propensity score matching, RT remained a good prognostic factor for overall survival.

CONCLUSION

The use of RT might be associated with a favorable clinical outcome in patients with locally advanced and metastatic pancreatic cancer. Further exploration of RT as a first-line therapy or second-line therapy for locally advanced or even metastatic pancreatic cancer is warranted.

Individually optimized stereotactic radiotherapy for pancreatic head tumors: A planning feasibility study

AIM

Aim of this study was to perform a planning feasibility analysis of a 3-level dose prescription using an IMRT-SIB technique.

BACKGROUND

Radiation therapy of locally advanced pancreatic cancer should administer a minimum dose to the duodenum and a very high dose to the vascular infiltration areas to improve the possibility of a radical resection.

MATERIALS AND METHODS

Fifteen patients with pancreatic head adenocarcinoma and vascular involvement were included. The duodenal PTV (PTVd) was defined as the GTV overlapping the duodenal PRV. Vascular CTV (CTVv) was defined as the surface of contact or infiltration between the tumor and vessel plus a 5 mm margin. Vascular PTV (PTVv) was considered as the CTVv plus an anisotropic margin. The tumor PTV (PTVt) was defined as the GTV plus a margin including the PTVv and excluding the PTVd. The following doses were prescribed: 30 Gy (6 Gy/fraction) to PTVd, 37.5 Gy (7.5 Gy/fraction) to PTVt, and 45 Gy (9 Gy/fraction) to PTVv, respectively. Treatment was planned with an IMRT technique.

RESULTS

The primary end-point (PTVv D_mean > 90%) was achieved in all patients. PTVv D_98% > 90% was achieved in 6 patients (40%). OARs constraints were achieved in all patients.

CONCLUSIONS

Although the PTVv D_95% > 95% objective was achieved only in 40% of patients, the study showed that in 100% of patients it was possible to administer a strongly differentiated mean/median dose. Prospective trials based on clinical application of this strategy seem to be justified in selected patients without overlap between PTVd and PTVv.

Modeling Combined Chemotherapy and Particle Therapy for Locally Advanced Pancreatic Cancer

Pancreatic ductal adenocarcinoma is the only cancer for which deaths are predicted to increase in 2014 and beyond. Combined radiochemotherapy protocols using gemcitabine and hypofractionated X-rays are ongoing in several clinical trials. Recent results indicate that charged particle therapy substantially increases local control of resectable and unresectable pancreas cancer, as predicted from previous radiobiology studies considering the high tumor hypoxia. Combination with chemotherapy improves the overall survival (OS). We compared published data on X-ray and charged particle clinical results with or without adjuvant chemotherapy calculating the biological effective dose. We show that chemoradiotherapy with protons or carbon ions results in 1 year OS significantly higher than those obtained with other treatment schedules. Further hypofractionation using charged particles may result in improved local control and survival. A comparative clinical trial using the standard X-ray scheme vs. the best current standard with carbon ions is crucial and may open new opportunities for this deadly disease.

Volumetric-modulated arc radiotherapy for pancreatic malignancies: dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy

Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction external beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.

Radiation dose responses for chemoradiation therapy of pancreatic cancer: an analysis of compiled clinical data using biophysical models

PURPOSE

We analyzed recent clinical data obtained from chemoradiation of unresectable, locally advanced pancreatic cancer (LAPC) in order to examine possible benefits from radiation therapy dose escalation.

METHODS AND MATERIALS

A modified linear quadratic model was used to fit clinical tumor response and survival data of chemoradiation treatments for LAPC reported from 20 institutions. Biophysical radiosensitivity parameters were extracted from the fits.

RESULTS

Examination of the clinical data demonstrated an enhancement in tumor response with higher irradiation dose, an important clinical result for palliation and quality of life. Little indication of improvement in 1-year survival with increased radiation dose was observed. Possible dose escalation schemes are proposed based on calculations of the biologically effective dose required for a 50% tumor response rate.

CONCLUSIONS

Based on the evaluation of tumor response data, the escalation of radiation dose presents potential clinical benefits which when combined with normal tissue complication analyses may result in improved treatment outcome for locally advanced pancreatic cancer patients.

Quality of life and toxicity of stereotactic radiotherapy in pancreatic tumors: a case series

AIM

To analyze the results of extracranial stereotactic radiotherapy (ESRT) experience in pancreatic cancer patients.

METHODS

Four noncoplanar fixed beams were used in all patients.

RESULTS

Analysis of 16 patients was carried out. Overall response rate was 56.2%. Fifteen patients experienced local and/or distant progression of disease (median follow-up: 24 months). Two-year local progression-free, distant progression-free, and overall survivals were 85.7%, 58.7%, and 50.0%, respectively. Toxicity was less than grade 2 in all, although 1 patient had severe duodenal bleeding. Quality of life scores were unchanged.

CONCLUSIONS

ESRT was associated with low complication rate, and not worsening the patients' quality of life.

A phase I/II study of gemcitabine-concurrent proton radiotherapy for locally advanced pancreatic cancer without distant metastasis

PURPOSE

We conducted the study to assess the feasibility and efficacy of gemcitabine-concurrent proton radiotherapy (GPT) for locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

Of all 50 patients who participated in the study, 5 patients with gastrointestinal (GI)-adjacent LAPC were enrolled in P-1 (50 Gy equivalent [GyE] in 25 fractions) and 5 patients with non-GI-adjacent LAPC in P-2 (70.2 GyE in 26 fractions), and 40 patients with LAPC regardless of GI-adjacency in P-3 (67.5 GyE in 25 fractions using the field-within-a-field technique). In every protocol, gemcitabine (800 mg/m(2)/week for 3 weeks) was administered concurrently. Every patient received adjuvant chemotherapy including gemcitabine after GPT within the tolerable limit.

RESULTS

The median follow-up period was 12.5 months. The scheduled GPT was feasible for all except 6 patients (12%) due to acute hematologic or GI toxicities. Grade 3 or greater late gastric ulcer and hemorrhage were seen in 5 patients (10%) in P-2 and P-3. The one-year freedom from local-progression, progression-free, and overall survival rates were 81.7%, 64.3%, and 76.8%, respectively.

CONCLUSION

GPT was feasible and showed high efficacy. Although the number of patients and the follow-up periods are insufficient, the clinical results seem very encouraging.

Interfractional dose variations in intensity-modulated radiotherapy with breath-hold for pancreatic cancer

PURPOSE

To investigate the interfractional dose variations for intensity-modulated radiotherapy (RT) combined with breath-hold (BH) at end-exhalation (EE) for pancreatic cancer.

METHODS AND MATERIALS

A total of 10 consecutive patients with pancreatic cancer were enrolled. Each patient was fixed in the supine position on an individualized vacuum pillow with both arms raised. Computed tomography (CT) scans were performed before RT, and three additional scans were performed during the course of chemoradiotherapy using a conventional RT technique. The CT data were acquired under EE-BH conditions (BH-CT) using a visual feedback technique. The intensity-modulated RT plan, which used five 15-MV coplanar ports, was designed on the initial BH-CT set with a prescription dose of 39 Gy at 2.6 Gy/fraction. After rigid image registration between the initial and subsequent BH-CT scans, the dose distributions were recalculated on the subsequent BH-CT images under the same conditions as in planning. Changes in the dose-volume metrics of the gross tumor volume (GTV), clinical target volume (CTV = GTV + 5 mm), stomach, and duodenum were evaluated.

RESULTS

For the GTV and clinical target volume (CTV), the 95th percentile of the interfractional variations in the maximal dose, mean dose, dose covering 95% volume of the region of structure, and percentage of the volume covered by the 90% isodose line were within ±3%. Although the volume covered by the 39 Gy isodose line for the stomach and duodenum did not exceed 0.1 mL at planning, the volume covered by the 39 Gy isodose line for these structures was up to 11.4 cm(3) and 1.8 cm(3), respectively.

CONCLUSIONS

Despite variations in the gastrointestinal state and abdominal wall position at EE, the GTV and CTV were mostly ensured at the planned dose, with the exception of 1 patient. Compared with the duodenum, large variations in the stomach volume receiving high-dose radiation were observed, which might be beyond the negligible range in achieving dose escalation with intensity-modulated RT combined with BH at EE.

Capecitabine based postoperative accelerated chemoradiation of pancreatic carcinoma. A dose-escalation study

The objective of this study was to evaluate the safety of escalating up to 55 Gy within five weeks, the dose of external beam radiotherapy to the previous tumor site concurrently with a fixed daily dose of capecitabine, in patients with resected pancreatic cancer.

MATERIAL AND METHODS

Patients with resected pancreatic carcinoma were eligible for this study. Capecitabine was administered at a daily dose of 1600 mg/m (2). Regional lymph nodes received a total radiation dose of 45 Gy with 1.8 Gy per fractions. The starting radiation dose to the tumor bed was 50.0 Gy (2.0 Gy/fraction, 25 fractions). Escalation was achieved up to a total dose of 55.0 Gy by increasing the fraction size by 0.2 Gy (2.2 Gy/fraction), while keeping the duration of radiotherapy to five weeks (25 fractions). A concomitant boost technique was used. Dose limiting toxicity (DLT) was defined as any grade>3 hematologic toxicity, grade>2 liver, renal, neurologic, gastrointestinal, or skin toxicity, by RTOG criteria, or any toxicity producing prolonged (> 10 days) radiotherapy interruption.

RESULTS AND DISCUSSION

Twelve patients entered the study (median age: 64 years). In the first cohort (six patients), no patient experienced DLT. Similarly in the second cohort, no DLT occurred. All 12 patients completed the planned regimen of therapy. Nine patients experienced grade 1-2 nausea and/or vomiting. Grade 2 hematological toxicity occurred in four patients. The results of our study indicate that a total radiation dose up to 55.0 Gy/5 weeks can be safely administered to the tumor bed, concurrently with capecitabine (1600 mg/m (2)) in patients with resected pancreatic carcinoma.

A systematic methodology review of phase I radiation dose escalation trials

BACKGROUND AND PURPOSE

The purpose of this review is to evaluate the methodology used in published phase I radiotherapy (RT) dose escalation trials. A specific emphasis was placed on the frequency of reporting late complications as endpoint.

MATERIALS AND METHODS

We performed a systematic literature review using a predefined search strategy to identify all phase I trials reporting on external radiotherapy dose escalation in cancer patients.

RESULTS

Fifty-three trials (phase I: n = 36, phase I-II: n = 17) fulfilled the inclusion criteria. Of these, 20 used a modified Fibonacci design for the RT dose escalation, but 32 did not specify a design. Late toxicity was variously defined as > 3 months (n = 43) or > 6 months (n = 3) after RT, or not defined (n = 7). In only nine studies the maximum tolerated dose (MTD) was related to late toxicity, while only half the studies reported the minimum follow-up period for dose escalation (n = 26).

CONCLUSION

In phase I RT trials, late complications are often not taken into account and there is currently no consensus on the methodology used for radiation dose escalation studies. We therefore propose a decision-tree algorithm which depends on the endpoint selected and whether a validated early surrogate endpoint is available, in order to choose the most appropriate study design.

External beam radiotherapy plus 24-hour continuous infusion of gemcitabine in unresectable pancreatic carcinoma: long-term results of a phase II study

PURPOSE

To evaluate the efficacy of gemcitabine-based chemoradiation (CT-RT) in treating patients (pts) affected by locally advanced pancreatic cancers (LAPC).

METHODS AND MATERIALS

Weekly gemcitabine (100 mg/m(2)) was given as a 24-hour infusion during the course of three-dimensional radiotherapy (50.4 Gy to the tumor, 39.6 Gy to the nodes). After CT-RT, pts received five cycles of sequential chemotherapy with gemcitabine (1000 mg/m(2); 1, 8, q21). Response rate was assessed according to World Health Organization criteria 6 weeks after the end of CT-RT. Local control (LC), time to progression (TTP), metastases-free survival (MFS), and overall survival (OS) were analyzed by the Kaplan Meier method.

RESULTS

Forty pts (male/female 22/18; median age 62 years, range, 36-76) were treated from 2000 to 2005. The majority had T4 tumour (n = 34, 85%), six pts (15%) had T3 tumour. Sixteen pts (40%) were node positive at diagnosis. Grade 3-4 acute toxicity was observed in 21 pts (52.5%). Thirty pts (75%) completed the treatment schedule. A clinical response was achieved in 12 pts (30%). With a median follow-up of 76 months (range, 32-98), 2-year LC was 39.6% (median, 12 months), 2-year TTP was 18.4% (median, 10 months), and 2-year MFS was 29.7% (median, 10 months). Two-year OS (25%; median, 15.5 months) compared with our previous study on 5-fluorouracil-based CT-RT (2.8%) was significantly improved (p <0.001).

CONCLUSIONS

Gemcitabine CT-RT seems correlated with improved outcomes. Healthier patients who are likely to complete the treatment schedule may benefit most from this therapy.

Rationale and appropriate use of chemotherapy and radiotherapy for pancreatic ductal adenocarcinoma

The emergence of effective systemic chemotherapy, along with the parallel development of new targeted cell signal inhibitors for pancreatic cancer treatment, has provided impetus for a re-examination of the appropriate use of chemotherapy and radiation therapy in this malignancy. In addition to exciting developments in the treatment of locally advanced and metastatic disease, new data have emerged regarding the efficacy of adjuvant and neoadjuvant therapy when combined with traditional surgical approaches such as a Whipple procedure. This review summarizes the sentinel clinical trials and discoveries that have influenced the development and deployment of scientifically based multidisciplinary care for today's patients, with a particular focus on modern radiation and chemotherapy.

A dosimetric analysis of dose escalation using two intensity-modulated radiation therapy techniques in locally advanced pancreatic carcinoma

PURPOSE

To perform an analysis of three-dimensional conformal radiation therapy (3D-CRT), sequential boost intensity-modulated radiation therapy (IMRTs), and integrated boost IMRT (IMRTi) for dose escalation in unresectable pancreatic carcinoma.

METHODS AND MATERIALS

Computed tomography images from 15 patients were used. Treatment plans were generated using 3D-CRT, IMRTs, and IMRTi for dose levels of 54, 59.4, and 64.8 Gy. Plans were analyzed for target coverage, doses to liver, kidneys, small bowel, and spinal cord.

RESULTS

Three-dimensional-CRT exceeded tolerance to small bowel in 1 of 15 (6.67%) patients at 54 Gy, and 4 of 15 (26.7%) patients at 59.4 and 64.8 Gy. 3D-CRT exceeded spinal cord tolerance in 1 of 15 patients (6.67%) at 59.4 Gy and liver constraints in 1 of 15 patients (6.67%) at 64.8 Gy; no IMRT plans exceeded tissue tolerance. Both IMRT techniques reduced the percentage of total kidney volume receiving 20 Gy (V20), the percentage of small bowel receiving 45 Gy (V45), and the percentage of liver receiving 35 Gy (V35). IMRTi appeared superior to IMRTs in reducing the total kidney V20 (p < 0.0001), right kidney V20 (p < 0.0001), and small bowel V45 (p = 0.02).

CONCLUSIONS

Sequential boost IMRT and IMRTi improved the ability to achieve normal tissue dose goals compared with 3D-CRT. IMRTi allowed dose escalation to 64.8 Gy with acceptable normal tissue doses and superior dosimetry compared with 3D-CRT and IMRTs.

The Prognostic Effect of Clinical Staging in Pancreatic Adenocarcinoma

BACKGROUND

The importance of pancreatic cancer staging is uncertain. The aim of this report was to evaluate the accuracy of combined standard imaging techniques in predicting the pathologic stage and to evaluate the prognostic effect of clinical staging to identify patient groups in which laparoscopy and laparotomy could be beneficial.

METHODS

Fifty-four patients were included in this analysis. The techniques used for clinical staging were endoscopic retrograde cholangiopancreatography, abdominal computed tomographic scan, and ultrasonography. All patients underwent both clinical and surgical/pathologic staging. A comparison was performed between presurgical stage and surgical/pathologic stage. The prognostic effect of different factors on survival was evaluated with both univariate (log-rank) and multivariate (Cox) analysis.

RESULTS

Sensitivity and specificity for vascular involvement were 73.9% and 96.3%, respectively. Sensitivity and specificity for nodal involvement were 63.6% and 95.4%, respectively. A total of 33.3% of patients showed a higher than expected pathologic stage, and 3.7% showed a lower than expected pathologic stage, by comparing clinical and pathologic evaluation. A highly significant correlation was observed between clinical T stage (P = .0067) and tumor diameter (P = .0037) and patient survival. Maximal prognostic differentiation was observed by dividing patients into two groups based on imaging results: group A (favorable prognosis) and group B (unfavorable prognosis). The median survival was 25.1 and 8.0 months for group A and B, respectively. Five-year survival was 20.1% and 0%, respectively (multivariate analysis: P = .0007).

CONCLUSIONS

Integrated standard imaging studies achieved reasonable diagnostic accuracy in our analysis. A single classification based on clinical stage and tumor diameter evaluated by imaging predicts prognosis in patients with pancreatic carcinoma.