The Role of Intraoperative Therapy by Electron Beam and Combination of Adjuvant Chemotherapy and External Radiotherapy in Carcinoma of the Pancreas

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in borderline-resected pancreatic cancer

•

Radiation dose-escalation with intraoperative electron beam radiation therapy to the posterior resection margin and/or to residual disease is feasible with limited toxicity.

•

Preoperative therapy prolongs the interval to surgery and IOERT, allowing an improved selection of patients who are candidates for local treatment intensification.

•

Primary systemic therapy combined with chemoradiation allows to boost with IOERT in over 70% of patients with R0 surgical tumour beds.

•

Median survival time ranges from 19 to 35 months in electron boosted patients.

•

Overall survival at 5 years of over 30% is reported by contemporary expert IOERT institutions.

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise RT modality to intensify the irradiation effect for cancer involving upper abdominal structures and organs, generally delivered with electrons (IOERT). Unresectable, borderline and resectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery. Prolonged preoperative treatment may act as a filter for selecting patients with occult resistant metastatic disease. Encouraging survival rates have been documented in patients treated with preoperative chemoradiation followed by radical surgery and IOERT (>20 months median survival, >35% survival at 3 years). Intensive preoperative treatment, including induction chemotherapy followed by chemoradiation and an IOERT boost, appears to prolong long-term survival within the subset of patients who remain relapse-free for>2 years (>30 months median survival; >40% survival at 3 years). Improvement of local control through higher RT doses has an impact on the survival of patients with a lower tendency towards disease spread. IOERT is a well-accepted approach in the clinical scenario (maturity and reproducibility of results), and extremely accurate in terms of dose-deposition characteristics and normal tissue sparing. The technique can be adapted to systemic therapy and surgical progress. International guidelines (National Comprehensive Cancer Network or NCCN guidelines) currently recommend use of IOERT in cases of close surgical margins and residual disease. We hereby report the ESTRO/ACROP recommendations for performing IOERT in borderline-resectable pancreatic cancer.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in unresected pancreatic cancer

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise sub-component of RT that can intensify the irradiation effect for cancer involving an anatomically well-defined volume, generally delivered with electrons (IOERT). Unresectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery. Prolonged preoperative treatment may act as a filter for selecting patients with occult resistant metastatic disease. Long-term survivors were observed among unresected patients treated with external beam RT and an IOERT boost (OS 6% at 3 years; 3% >5 years). Improvement of local control through higher RT doses has an impact on the survival of patients with a lower tendency towards disease spread. IOERT is a well-accepted asset in the clinical scenario (maturity and reproducibility of results, albeit of low official level of evidence) and extremely accurate in terms of dose-deposit characteristics and normal tissue sparing. It is a technique that can be integrated with systemic therapy and surgical progress. International guidelines (National Comprehensive Cancer Network or NCCN guidelines) currently recommend the use of IOERT in cases of close surgical margins and residual disease. We report the ESTRO/ACROP recommendations for performing IOERT in unresected pancreatic cancer.

Adjuvant therapy for pancreatic cancer

Pancreatic cancer is a challenging malignancy to treat, as less than one-fifth of diagnosed cases are resectable, surgery is complex and postoperative recovery slow, treated patients tend to relapse and overall survival rates are low. It is one of the leading causes of cancer-related mortality. Adjuvant therapy has been employed in resectable disease, to target micrometastases and improve prognosis. Chemotherapy, chemoradiotherapy (chemoRT) and chemoradiotherapy (chemoRT) followed on by chemotherapy have been evaluated in randomised controlled trials. The European Study Group for Pancreatic Cancer (ESPAC)-1 and CONKO-001 trials clearly established the survival advantage of adjuvant chemotherapy with 5 fluorouracil (5FU) plus folinic acid and gemcitabine respectively over no chemotherapy. The ESPAC-3 (version 2) trial demonstrated equivalence between 5FU plus folinic acid and gemcitabine in terms of survival parameters, though gemcitabine had a better toxicity profile. The results of these key studies, together with smaller ones have been subjected to meta-analyses, with confirmation of improved survival with adjuvant systemic chemotherapy. The EORTC-40891 and ESPAC-1 trials found no survival advantage with adjuvant chemoRT compared to observation, and this has been reflected in a subsequent meta-analysis. The popularisation of chemoRT, with follow on chemotherapy (versus observation) was based on the small underpowered GITSG trial. The ESPAC-1 trial was unable to find a survival benefit for chemoRT, with follow on chemotherapy compared to observation. The RTOG-9704 trial assessed chemoRT with follow on chemotherapy in both arms and found no difference between survival in the gemcitabine and 5FU arms. There has never been a published head-to-head randomised comparison of adjuvant chemotherapy to chemoRT, with follow on chemotherapy. Ongoing randomised trials are looking into adjuvant combination chemotherapy, chemotherapy with follow on chemoRT, and neoadjuvant therapy. Novel agents continue to be assessed in early phase trials with a major emphasis on predictive and prognostic biomarkers. Based on the available evidence, adjuvant chemotherapy with gemcitabine or 5FU/folinic acid is the current recommended gold standard in the management of resected pancreatic cancer.

Intraoperative radiotherapy for resected pancreatic cancer: a multi-institutional retrospective analysis of 210 patients

PURPOSE

To retrospectively analyze the results of intraoperative radiotherapy (IORT) with or without external beam radiotherapy (EBRT) for resected pancreatic cancer.

METHODS AND MATERIALS

The records of 210 patients treated with gross complete resection (R0: 147 patients; R1: 63 patients) and IORT with or without EBRT were reviewed. One hundred forty-seven patients (70.0%) were treated without EBRT and 114 patients (54.3%) were treated in conjunction with chemotherapy. The median doses of IORT and EBRT were 25 Gy (range, 20-30 Gy) and 45 Gy (range, 20-60Gy), respectively. The median follow-up of the surviving 62 patients was 26.3 months (range, 2.7-90.5 months).

RESULTS

At the time of this analysis, 150 of 210 patients (71.4%) had disease recurrences. Local failure was observed in 31 patients (14.8%), and the 2-year local control rate in all patients was 83.7%. The median survival time and the 2-year actuarial overall survival (OS) in all 210 patients were 19.1 months and 42.1%, respectively. Patients treated with IORT and chemotherapy had a significantly more favorable OS than those treated with IORT alone (p = 0.0011). On univariate analysis, chemotherapy use, degree of resection, carbohydrate antigen 19-9, and pathological N stage had a significant impact on OS and on multivariate analysis; these four factors were significant prognostic factors. Late gastrointestinal morbidity of NCI-CTC Grade 4 was observed in 7 patients (3.3%).

CONCLUSION

IORT yields an excellent local control rate for resected pancreatic cancer with few frequencies of severe late toxicity, and IORT combined with chemotherapy confers a survival benefit compared with that of IORT alone.

Current state of adjuvant therapy in resected pancreatic adenocarcinoma

Pancreatic carcinoma cannot generally be cured by surgery alone. This review summarizes the development of adjuvant therapy over the past two decades. Four randomized controlled trials compare long-term survival of different treatments. The small GITSG-study supports combined chemoradiation, but the EORTC-study found no significant effect. A Norwegian study of adjuvant chemotherapy found an increased median survival, but no effect beyond two years. The large ESPAC-1 study shows a benefit for 5-FU based chemotherapy, while chemoradiation had a negative effect. Thus, evidence favours adjuvant therapy, but 5-FU may not be the ultimate drug. Support for gemcitabine is given by preliminary data from a German randomized trial, and further American and European studies are upcoming. However, postoperative therapy is problematic, as 20-30% of resected patients never undergo treatment because of slow recovery or other reasons. Preoperative therapy has some theoretical advantages, and moreover, patients with rapidly progressive disease may be spared surgery. Randomized controlled trials are lacking, but published results compare well with postoperative, adjuvant therapy. The value of locally targeted therapy is difficult to assess. Reasonable results have been obtained with regional chemotherapy, whereas intraoperative radiotherapy does not seem to increase survival despite reducing reducing local recurrences.

Intraoperative radiation therapy in resected pancreatic carcinoma: long-term analysis

PURPOSE

The combination of external radiotherapy (RT) plus intraoperative radiotherapy (IORT) in patients with pancreatic cancer is still debated. This study presents long-term results (minimum follow-up, 102 months) for 26 patients undergoing integrated adjuvant RT (external RT+IORT).

METHODS AND MATERIALS

From 1990 to 1995, a total of 17 patients with pancreatic cancer underwent IORT (10 Gy) and postoperative external RT (50.4 Gy). Preoperative "flash" RT was included for the last 9 patients. The liver and pancreatic head received 5 Gy (two 2.5-Gy fractions) the day before surgery. In the subsequent period (1996-1998), 9 patients underwent preoperative concomitant chemoradiation (39.6 Gy) with 5-fluorouracil, IORT (10 Gy), and adjuvant chemotherapy.

RESULTS

Preoperative chemoradiation was completed in all patients, whereas postoperative therapy was completed in 13 of 17 patients. All 26 patients underwent pancreatectomy (25 R0 and one R1 resections). One patient died of postoperative complications (3.8%) not related to IORT. The 9 patients undergoing concomitant chemoradiation were candidates for adjuvant chemotherapy; however, only 4 of 9 underwent adjuvant chemotherapy. At last follow-up, 4 patients (15.4%) were alive and disease free. Disease recurrence was documented in 20 patients (76.9%). Sixteen patients (61.5%) showed distant metastasis, and 5 patients (19.2%) showed local recurrence. The incidence of local recurrence in R0 patients was 4 of 25 (16.0%). The overall 5-year survival rate was 15.4%. There was significant correlation with overall survival of tumor diameter (p=0.019).

CONCLUSIONS

The incidence of local recurrence in this long follow-up series (19.2%) was definitely less than that reported in other studies of adjuvant RT (approximately 50%), suggesting a positive impact on local control of integrated adjuvant RT (IORT+external RT).

Early experience with intraoperative radiotherapy in patients with resected pancreatic adenocarcinoma

BACKGROUND

The use of intraoperative radiotherapy (IORT) in patients with resected pancreatic adenocarcinoma has not been clearly defined.

METHODS

The medical records of our first 22 patients receiving IORT for resected pancreatic adenocarcinoma (2001 to 2006) were reviewed and compared with the records of 27 consecutive patients not receiving IORT for resected pancreatic adenocarcinoma (2004 to 2006).

RESULTS

There were no 30-day mortalities in either group, and complication rates were similar. Local recurrence occurred in 18% in the IORT group (median 14 months) and 12% in the no-IORT group (median 7 months). Distant recurrence occurred in 47% in the IORT group (median 11 months) and 32% in the no-IORT group (median 6.5 months). Median overall, stage-specific, and location-specific survival did not differ between the groups.

CONCLUSIONS

Although limited in size and follow-up, our experience showed that complications, recurrence, and survival were not affected by IORT, but time to recurrence may be longer with IORT.

Adjuvant therapy in pancreatic cancer: a critical appraisal

Adenocarcinoma of the pancreas carries a grim prognosis. Surgery is currently the only curative option, but even the few patients undergoing complete resection of early localised disease run a high risk for relapse and death. Although numerous clinical trials have been conducted during the past 20 years to find an effective adjuvant treatment, thus far no general consensus on the most appropriate regimen has been reached. In a small randomised study performed in the 1980s by the GITSG (Gastrointestinal Tumor Study Group), encouraging results were obtained with fluorouracil (5-FU)-based split-course chemoradiotherapy, but these findings were not confirmed in a randomised study initiated some years later by the EORTC (European Organisation for Research and Treatment of Cancer). More recently, the ESPAC (European Study Group for Pancreatic Cancer)-1 trial even indicated a detrimental effect of chemoradiotherapy, while chemotherapy with 5-FU was shown to have a significant positive impact on long-term survival. However, this latter finding is in contrast to earlier studies of adjuvant chemotherapy with 5-FU combinations from Norway and Japan that did not suggest a prolonged beneficial effect of 5-FU on survival. Thus, the results for adjuvant regimens based on systemic 5-FU with or without external radiotherapy are conflicting. Clinical experience with intraoperative radiotherapy or regionally targeted chemotherapy to prevent local relapse, though encouraging, is still preliminary. More recently, gemcitabine, which is the most effective single agent in advanced pancreatic cancer, has also been evaluated in the adjuvant setting. The RTOG (Radiation Therapy Oncology Group)-9704 trial demonstrated that gemcitabine is superior to 5-FU as an addition to chemoradiotherapy, but the results did not allow conclusions about the value of radiation in the combined modality approach. The Charité Onkologie CONKO-001 is a randomised trial from Germany and Austria that compared adjuvant gemcitabine with observation alone. Gemcitabine was very well tolerated and almost doubled median disease-free survival and overall survival rate at 5 years, although the advantage in overall survival failed to reach statistical significance. In summary, the available data from randomised clinical trials of adjuvant therapy suggest that (i) chemoradiotherapy has no obvious advantage compared with chemotherapy alone; and (ii) chemotherapy with gemcitabine is effective and probably offers the best benefit-risk ratio of all currently available adjuvant treatment options.

Adjuvant therapy for pancreatic cancer

Ductal adenocarcinoma of the pancreas is one of the leading causes of cancer death in the UK, Europe and US, with incidence closely paralleling mortality. Until recently, enthusiasm for treating these patients was limited for a number of reasons: the majority of patients undergoing surgery would relapse early, adjuvant treatment was of unproven value and systemic therapy in advanced disease had only a small chance of a short-term benefit. More recently, however, it has become recognised that specialist surgery can improve results and there is evidence that adjuvant chemotherapy has a significant advantage in terms of 5-year survival. In particular adjuvant systemic 5-fluorouracil with folinic acid can result in 5-year survival of < or = 29% (compared with 11% for controls) and adjuvant gemcitabine can improve disease-free survival to 13.4 months from a median of 6.9 months in controls, but not overall survival. In contrast the role of adjuvant chemoradiation in addition to chemotherapy remains unproven and the survival results appear to be inferior to systemic chemotherapy alone. New agents, such as capecitabine and erlotinib, are emerging with some activity in this dismal disease signalling hope for the future.

Primary advanced unresectable pancreatic cancer

Median as well as overall survival of pancreatic cancer patients in the advanced stage is extremely low despite advances in cancer therapy regarding tumor cell biology, therapy resistance, and diagnosis. In matters of chemoradiation therapy (CRT) in locally advanced pancreatic cancer, favorable positive effect has been reached with different radiotherapy proceedings such as intraoperative radiation therapy with or without external chemo-/radiation therapy or with CRT alone with regard to local tumor pain, local tumor remission, or local control of disease and overall survival. Primary (chemo-) radiation therapy only rarely leads to local remission. Intraoperative radiation therapy (IORT) merely reaches pain palliation in most cases. By administering up-to-date primary CRT, especially with gemcitabine-associated CRT, local remission in up to 50% of patients can be observed. By applying neoadjuvant CRT, better resectability and the reduction of postoperative positive lymph node metastasis has been seen in patients with resectable or possibly resectable pancreatic cancer. With primary CRT, resectability can also be achieved in patients with primary unresectable pancreatic cancer. It has been shown at the evaluation of patients' progression samples--either treated with neoadjuvant or primarily with radiotherapy (with conventional radiation technique)--that the rate of local recurrence or local progression can be reduced in comparison with historical cohorts. By contrast, the rate on distant metastases was not affected. Whereas concurrent CRT leads to favorable local tumor control, this procedure has a minor effect as to the survival in most of the studies. Because metastases occur mostly out of the irradiation field and because of partly advanced local tumor progression, the concept of combined CRT with continuing chemotherapy was developed. Median survival of pancreatic patients in the advanced stage is approx. 3-5 months, with a 12-month survival probability of 10% despite advances in cancer therapy. On the other hand, the 5-year survival probability is 0.4%-3.0%. The causes of such a dismal prognosis can be understood first of all in the commonly late diagnosis, second in the aggressive tumor cell biology with continuing therapy resistance, and finally because an acceptable resection rate can be achieved only in specialized centers. Only 10%-15% of patients can be resected after the diagnosis of pancreatic cancer. Resection is considered a potential curative therapy. However, median survival of these patients amounts to only 13-18 months, with a 5-year survival of 10%-20%. The survival rate did not improve with a radical resection and extended lymphadenectomy. Furthermore, 15%-30% of primary nonmetastatic pancreatic cancer is unresectable due to extended vessel infiltration at time of diagnosis. The prognosis for these patients is very dismal due to lack of specific therapy; moreover, median overall survival is a maximum of 6-8 months.

Adjuvant treatment

Exocrine pancreatic cancer (pancreatic ductal adenocarcinoma) is one of the leading causes of cancer deaths in the western world, accounting for 5% of all cancer-related deaths. Only a small percentage of patients with pancreatic cancer are able to undergo potentially curative resection, even in specialized centres, and prognosis remains poor after successful surgery. Over the last few years efforts have been directed towards the development of adjuvant therapies in attempts to improve outcome. The main trials of adjuvant chemotherapy, chemoradiotherapy and chemoradiotherapy with follow-on chemotherapy are described in this paper, followed by the results of the ESPAC-1 trial and the status of ESPAC-2 and -3 trials.

Adjuvant radiotherapy in resectable pancreatic carcinoma

AIM

Pancreatic cancer is a near fatal disease. External beam radiotherapy and intraoperative radiation therapy (IORT) has been proposed with the aim to improve clinical outcome in resectable tumors. The aim of this study is to assess the feasibility and outcome in patients with cT1-3 pancreatic cancer, treated with surgery, external beam radiotherapy and IORT.

METHODS

From 1990 to 1996, 17 patients with clinical stage T1-3N0-1M0 adenocarcinoma of the head of the pancreas were treated with pancreatectomy and pre- (nine patients: 5 Gy), intra- (all patients: 10 Gy) and post-operative (all patients: 50 Gy) radiotherapy. The pathologic T stages were: 4 pT2 and 13 pT3. The pathologic N stages were: 9 pN0 and 8 pN1. Minimum follow-up in living patients was 60 months.

RESULTS

No perioperative mortalities were recorded. Two patients showed postoperative morbidity (11.8%) which required a subsequent laparotomy. The disease-free survival at 1, 3 and 5 years was 41, 23 and 18%, respectively (median: 9 months). The overall survival at 1, 3 and 5 years was 70%, 41% and 18%, respectively (median: 17.5 months). Three patients developed local failure (17.6%) and 12 patients showed distant metastases (70.6%). Univariate analysis (logrank) showed: a significant correlation between both N-stage and retroperitoneal involvement (RPI) with local control (N-stage: P=0.0155; RPI:P =0.0295), a significant correlation between maximum tumor size and metastases-free survival (P=0.0167) and overall survival (P=0.0241); the female gender was another predictor of prolonged survival (P= 0.0465). Multivariate analysis (Cox) showed a significant impact of N-stage and retroperitoneal involvement on local control and also a significant correlation between perineural involvement and tumor diameter with metastases-free survival.

CONCLUSIONS

These results are similar to those of other published series and suggest that this approach is feasible with acceptable local control and survival, especially in patients with small tumors (<2.5 cm: 5 year survival=33.3%) and in female patients (5 year survival=30%). Due to the impact of gender, tumor diameter and N stage on prognosis, in the design of future trials a stratification of patients based on these categories should be considered. The search of effective chemotherapeutic agents is required, to reduce the high incidence of distant metastases, especially in larger tumors.

Analysis of the clinical benefit of intraoperative radiotherapy in patients undergoing macroscopically curative resection for pancreatic cancer

PURPOSE

To determine the survival of pancreatic cancer patients treated with intraoperative radiotherapy (IORT) and/or external beam radiation therapy (EBRT) following macroscopically curative resection.

METHODS AND MATERIALS

One hundred and thirty-eight patients with pancreatic cancer who had undergone potentially curative total or regional pancreatectomy between 1980 and 1997 were retrospectively analyzed. Among the 138 patients, 98 had a pathologically negative surgical margin and the remaining 40 patients had a positive surgical margin. The usual EBRT dose was 45-55 Gy with a daily fraction of 1.5-2.0 Gy. The median IORT dose was 25 Gy in a single fraction.

RESULTS

The 2-year cause-specific survival rate of patients with pathologically negative surgical margins was 19%, and that of patients with positive margins was 4% (p < 0.005). Although the median survival time (MST) of patients with negative margins treated with IORT and EBRT was significantly longer than that of those treated with operation alone (17 vs. 11 months), no significant difference in survival curves was observed. In patients with positive surgical margins in peripancreatic soft tissue, the difference between the survival curve of patients treated with surgery alone and that of those treated with surgery and radiation therapy was borderline significant (p < 0.10). Patients receiving intraarterial or intraportal infusion chemotherapy had significantly improved survival rates compared with those who did not receive it (p < 0.05).

CONCLUSION

Although the MST was longer in patients with negative margins receiving IORT and EBRT than in those receiving no radiation, improved long-term survival by IORT and/or EBRT was not suggested. In patients with positive margins, our results obtained by IORT/EBRT were encouraging. Randomized studies with much higher patient numbers are necessary to define the role of IORT in curatively resected pancreatic cancer.

[Concomitant chemoradiotherapy and preoperative radiotherapy in exocrine pancreatic adenocarcinoma]

The prognosis of pancreatic adenocarcinoma remains poor, with a 5-year survival rate lower than 5%. Resection, the gold standard treatment, can be performed in less than 10% of patients. Following surgery, the median survival is 12 months. Concomitant chemoradiation, as an adjuvant treatment could be superior to surgery alone, in terms of survival; controlled trials are currently performed. Neoadjuvant chemoradiation is a new approach, potentially able to increase survival and resection rate. Finally, current data regarding intraoperative irradiation are exposed.

Tumor response and patterns of failure following intraoperative radiotherapy for unresectable pancreatic cancer--evaluation by computed tomography

Tumor response and patterns of failure following intraoperative radiotherapy (IORT) of 42 patients with unresectable pancreatic cancers were evaluated by computed tomography (CT). At the time of maximum tumor regression, the tumor response rate following IORT was 52%, with three tumors showing CR. The median time of maximum tumor regression was 3 months after IORT. When tumor response was evaluated within 2 months of IORT, no significant difference in survival rate between responders and non-responders was noted. However, when tumor response was evaluated 3-6 months after IORT, the responders showed a significantly better survival rate than the non-responders. Local tumor recurrence, liver metastasis, and peritoneal dissemination were major causes of failure after IORT for unresectable pancreatic cancers. In addition, the median time of detection of these findings by CT was 2-3 months after IORT. Thus, our results indicate that CT performed 3-4 months after IORT is most important for predicting clinical outcome.

Review article: current treatment and optimal patient management in pancreatic cancer

This review analyses the current state of knowledge and understanding concerning the optimum treatment and therapeutic management of patients who suffer from pancreatic cancer. It outlines recent advances in scientific understanding and assesses their potential future value to clinicians in confronting this disease. Despite a significant expansion in scientific knowledge relating to factors underlying the early development of pancreatic carcinoma, the clinician continues to be restricted to a severely limited therapeutic armoury for this disease. Local therapies (surgery and radiation) are inevitably of limited value in the face of a disease that is normally encountered at a stage where metastasis is already highly developed. Despite such limitations, however, surgery performed in specialist units may be of value for 10-20% of patients, with a 5-year survival rate in such units of between 10 and 24%. This may be improved even further by appropriate use of adjuvant treatment. The advanced stage of the disease when normally encountered emphasizes the potential value of systemic treatment in this therapeutic area. Unfortunately systemic treatment (chemotherapy) has been found to be ineffective to date in significantly extending survival, with a low rate and duration of remission being identified in most trials. The challenge for both the health service and the pharmaceutical industry is to harness recent and future developments in scientific knowledge to the practical benefit of clinicians. Where cure is possible it should be vigorously pursued; where it is not, in this field above all others, clinicians have a duty of care. To achieve this it is necessary to abandon the therapeutic nihilism that has characterized the attitudes of clinicians towards this disease in the past. It is time that such nihilism was replaced by a recognition of the challenges and the opportunities available to clinicians in enhancing the quantity and quality of life available to patients. The dictum of 'curing whenever possible but caring always' should be the future therapeutic philosophy used to guide clinicians in this important and rapidly changing therapeutic area.

Intraoperative radiotherapy in resected pancreatic cancer: feasibility and results

BACKGROUND AND PURPOSE

To evaluate the impact of intraoperative radiotherapy (IORT) combined with postoperative external beam irradiation in patients with pancreatic cancer treated with curative surgical resection.

MATERIALS AND METHODS

From January 1986 to April 1995 25 patients (11 male and 14 female, median age 61 years) underwent a curative resection with IORT for pancreatic adenocarcinoma. The tumour was located in the head of the pancreatic gland in 22 patients, in the body in two patients and in the tail in one patient. The pathological stage was pT1 in nine patients, pT2 in nine patients, pT3 in seven patients, pN0 in 14 patients and pN1 in 11 patients. All the patients were pM0. A pancreaticoduodenectomy was performed in 22 patients, a distal pancreatectomy was performed in two patients and a total pancreatectomy was performed in one patient. The resection was considered to be complete in 20 patients. One patient had microscopic residual disease and gross residual disease was present in four patients. IORT using electrons with a median energy of 12 MeV was performed in all the patients with doses ranging from 12 to 25 Gy. Postoperative EBRT was delivered to 20 patients (median dose 44 Gy). Concurrent chemotherapy with 5-fluorouracil was given to seven patients.

RESULTS

The overall survival was 56% at 1 year, 20% at 2 years and 10% at 5 years. Nine local failures were observed. Twelve patients developed metastases without local recurrence. Twenty patients died from tumour progression and two patients died from early postoperative complications. Three patients are still alive; two patients in complete response at 17 and 94 months and one patient with hepatic metastases at 13 months.

CONCLUSION

IORT after complete resection combined with postoperative external beam irradiation is feasible and well tolerated in patients with pancreatic adenocarcinoma.

External and intraoperative radiotherapy for resectable and unresectable pancreatic cancer: analysis of survival rates and complications

PURPOSE

Clinical results of intraoperative radiotherapy (IORT) and/or external beam radiotherapy (EBRT) for both resectable and unresectable pancreatic cancer were analyzed.

METHODS AND MATERIALS

Between 1980 and 1995, 332 patients with pancreatic cancer were treated with surgery and/or radiation therapy (RT). Of the 332 patients, 157 patients were treated with surgical resection of pancreatic tumor, and the remaining 175 patients had unresectable pancreatic tumors. Among the 157 patients with resected pancreatic cancer, 62 patients were not treated with RT, while 40 patients were treated with EBRT alone (mean RT dose; 46.3 Gy) and 55 patients with IORT (25.2 Gy) +/- EBRT (44.0 Gy). On the other hand, among the 175 patients with unresectable pancreatic cancer, 58 patients were not treated with RT, 46 patients were treated with EBRT alone (39.2 Gy), and the remaining 71 patients with IORT (29.3 Gy) +/- EBRT (41.2 Gy).

RESULTS

For 87 patients with curative resection, the median survival times (MSTs) of the no-RT, the EBRT, and the IORT +/- EBRT groups were 10.4, 13.0, and 15.5 months, respectively, without significant difference. For 70 patients with noncurative resection, the MSTs of the no-RT, the EBRT, and the IORT +/- EBRT groups were 5.3, 8.7, and 6.5 months, respectively. When the EBRT and the IORT +/- EBRT groups were combined, the survival rate was significantly higher than that of the no RT group for noncuratively resected pancreatic cancers (log rank test; p = 0.028). The 2-year survival probability of the IORT +/- EBRT group (16%) was higher than that of the EBRT group (0%). For unresectable pancreatic cancer, the MSTs of 52 patients without distant metastases were 6.7 months for palliative surgery alone, 7.6 months for EBRT alone, and 8.2 months for IORT +/- EBRT. The survival curve of the IORT +/- EBRT group was significantly better than that of the no-RT group (p < 0.05), and the difference between the IORT +/- EBRT and the EBRT alone groups was marginally significant (p = 0.056). In addition, the 2-year survival probability for the IORT +/- EBRT group was 14%, while no 2-year survival was observed in the no RT or the EBRT groups. Multivariate analysis using the Cox proportional hazards model revealed that tumor size, stage (Stages 1, 2 vs. Stages 3, 4), and curability of resection were significant variables for resectable pancreatic cancer, while distant metastases and performance of IORT were significant variables for unresectable pancreatic cancer. The dose of EBRT was a marginally significant factor for both resectable and unresectable tumors (both p = 0.06). In terms of complications, ulcers of gastrointestinal tract were noted in 14% of the 126 patients treated with IORT.

CONCLUSION

Although prolongation of the MST by IORT was not remarkable, long survivals (>2 years) were obtained by IORT +/- EBRT for noncuratively resected and unresectable pancreatic cancer. IORT combined with EBRT is indicated for noncurative resected or unresectable pancreatic cancer without distant metastases.