A 10-year experience of intraoperative radiotherapy for gastric carcinoma and a new surgical method of creating a wider irradiation field for cases of total gastrectomy patients

Intraoperative radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

Association between serum vitamin D levels and gastric cancer: A retrospective chart analysis

AIM

To determine whether there is an increased risk of gastric adenocarcinoma associated with vitamin D deficiency (VDd).

METHODS

A retrospective case control study was performed of all patients diagnosed with gastric adenocarcinoma between 2005 and 2015. After we excluded the patients without a documented vitamin D level, 49 patients were included in our study.

RESULTS

The average age of patients with gastric adenocarcinoma and documented vitamin D level was 64 years old (95%CI: 27-86) and average vitamin D level was 20.8 mg/dL (95%CI: 4-44). Compared to a matched control group, the prevalence of VDd/insufficiency in patients with gastric adenocarcinoma was significantly higher than normal vitamin D levels (83.7% vs 16.3%). Forty-one patients (83.7%) with adenocarcinoma showed VDd/insufficiency compared to 18 (37%) patients with normal vitamin D level without gastric cancer (OR: 8.8, 95%CI: 5-22, P value < 0.0001). The average age of males with gastric adenocarcinoma diagnosis was 60 years old vs 68 years old for females (P = 0.01). Stage II gastric adenocarcinoma was the most prevalent in our study (37%).

CONCLUSION

We reported a positive relationship between VDd and gastric adenocarcinoma, that is to say, patients with decreased VDd levels have an increased propensity for gastric adenocarcinoma.

Benefits from adjuvant intraoperative radiotherapy treatment for gastric cancer: A meta-analysis

The benefits of adjuvant intraoperative radiotherapy (IORT) for resectable gastric cancer have been extensively studied, but data on the survival rate remains equivocal. A meta-analysis was performed of the studies involving the use of IORT for resectable gastric cancer using web-based databases. Hazard ratios (HRs) describing the impact of adjuvant IORT on the overall survival (OS) rate and locoregional control were extracted directly from the original studies or calculated from survival curves. A meta-analysis of four studies that provided OS data revealed that IORT had no significant impact on OS [HR, 0.97; 95% confidence interval (CI), 0.75-1.26; P=0.837]. In the three studies testing the efficacy of IORT for OS in the subgroup of patients with stage III disease, there was a significantly improved OS (HR, 0.60; 95% CI, 0.40-0.89; P=0.011). Significant locoregional control improvement was observed in the four studies that provided locoregional control data (HR 0.40; 95% CI, 0.26-0.62; P<0.001). This meta-analysis showed a statistically significant locoregional control benefit with the addition of IORT in patients with resectable gastric cancer. In addition, the available data revealed that adjuvant IORT may provide promising results on the survival rate for the subgroup of patients with stage III disease. Further study is required to optimize the implementation of adjuvant IORT for gastric cancer with regard to patient selection and integration with systemic therapy.

Intraoperative radiotherapy combined with adjuvant chemoradiotherapy for locally advanced gastric adenocarcinoma

PURPOSE

To evaluate the efficacy of intraoperative radiotherapy (IORT) followed by concurrent chemotherapy and external beam RT (EBRT) in the treatment of locally advanced gastric adenocarcinoma.

METHODS AND MATERIALS

A total of 97 consecutive and nonselected patients with newly diagnosed Stage T3, T4, or N+ adenocarcinoma of the stomach underwent gastrectomy with D2 lymph node dissection between March 2003 and October 2005. Of the 97 patients, 51 received adjuvant concurrent chemotherapy (5-fluorouracil, leucovorin, docetaxel, and cisplatin) and EBRT (EBRT group) and 46 received IORT (dose range, 12-15 Gy) immediately after gastrectomy and lymph node dissection before concurrent chemoradiotherapy (EBRT+IORT group).

RESULTS

After a median follow-up of 24 months, the 3-year locoregional control rate was 77% and 63% in the two groups with or without IORT, respectively (p = 0.05). The 3-year overall survival and disease-free survival rate was 47% and 36% in the EBRT group and 56% and 44% in the EBRT+IORT group, respectively (p > 0.05). Multivariate analyses revealed that the use of IORT, presence of residual disease after surgery, and pN category were independent prognostic factors for locoregional control and that IORT, pN, and pT categories were independent prognostic factors for overall survival (p < 0.05). Four patients experienced Grade 3 or 4 late complications, but no significant difference was observed between the two groups.

CONCLUSIONS

Radical gastrectomy with D2 lymph node dissection and IORT followed by adjuvant chemoradiotherapy appeared to be feasible and well-tolerated in the treatment of locally advanced gastric cancer. The addition of IORT to the trimodality treatment significantly improved the 3-year locoregional control rate.

Long-term results after intraoperative radiation therapy for gastric cancer

PURPOSE

We retrospectively analyzed the impact of intraoperative radiation therapy (IORT) on long-term survival in patients with resectable gastric cancer.

METHODS AND MATERIALS

From 1991 to 2001, a total of 84 patients with gastric neoplasms underwent gastectomy or subtotal resection with IORT (23 Gy, 6-15 MeV; IORT-positive [IORT(+)] group). Patients with a history of additional neoadjuvant chemotherapy, histologically confirmed R1 or R2 resection, or reoperation with curative intention after local recurrence were excluded from further analysis. The remaining 61 patients were retrospectively matched with 61 patients without IORT (IORT-negative [IORT(-)] group) for Union Internationale Contre le Cancer (UICC) stage, patient age, histologic grading, extent of surgery, and level of lymph node dissection. Subgroups included postoperative UICC Stages I (n = 31), II (n = 11), III (n = 14), and IV (n = 5).

RESULTS

Mean follow-up was 4.8 years in the IORT(+) group and 5.0 years in the IORT(-) group. The overall 5-year patient survival rate was 58% in the IORT(+) group vs. 59% in the IORT(-) group (p = 0.99). Subgroup analysis showed no impact of IORT on 5-year patient survival for those with UICC Stages I/II (76% vs. 80%; p = 0.87) and III/IV (21% vs. 14%, IORT(+) vs. IORT(-) group; p = 0.30). Perioperative mortality rates were 4.9% and 4.9% in the IORT(+) vs. IORT(-) group. Total surgical complications were more common in the IORT(+) than IORT(-) group (44.3% vs. 19.7%; p < 0.05). The locoregional tumor recurrence rate was 9.8% in the IORT(+) group.

CONCLUSIONS

Use of IORT was associated with low locoregional tumor recurrence, but had no benefit on long-term survival while significantly increasing surgical morbidity in patients with curable gastric cancer.

Radiotherapy in gastric cancer: a systematic review of literature and new perspectives

Gastric cancer is still a major problem for oncologists. Surgery is the main therapeutic approach; a complete surgical resection is usually necessary to offer potentially curative therapy to patients with adenocarcinoma of the stomach. However, many patients with more locally advanced tumors will experience local and distal recurrences. When a recurrence occurs, only palliative therapy is possible. In operable gastric cancer, both the extent of surgery and the value of adjuvant treatment remain subject to considerable international controversies. To improve local control, surgeons address the role of standardized surgery and of more extended surgery. Radiotherapy appears to improve local control and survival in the adjuvant arms, but perspective randomized trials are scarce and reported over many years. Retrospective experience demonstrated a low local recurrence rate, but was affected by large heterogeneity. However, evidence published in the last few years, improved radiotherapy technologies, better knowledge of the at-risk areas (enabling smaller radiotherapy volumes) and growing interest in neoadjuvant approaches support the role of radiotherapy in gastric cancer.

Intraoperative radiotherapy for treatment of locally advanced and recurrent esophageal and gastric adenocarcinomas

Intraoperative radiotherapy (IORT) allows delivery of radiotherapy doses in excess of those typically deliverable with conventional external beam radiotherapy. IORT has potential utility in clinical situations, such as treatment of esophageal and gastric malignancies, in which the radiation tolerance of normal organs limits the dose that can be given with conventional radiotherapy techniques. We reviewed the records of 50 patients who received IORT for locally advanced primary or recurrent gastric or esophageal adenocarcinomas deemed unresectable for cure. IORT was given as a single fraction of electron beam radiotherapy (10-25 Gy) after maximal tumor resection: R0 in 42%, R1 in 46%, and R2 in 12%. Forty-eight patients also received external beam radiotherapy (8-55 Gy), 46 received radiosensitizing chemotherapy, and nine received systemic chemotherapy after radiotherapy. Outcomes were estimated with Kaplan-Meier analysis. Median survival was 1.6 years. Overall survival at 1, 2, and 3 years was 70%, 40%, and 27%. Of 42 patients who died, 37 died from cancer progression and three from multifactorial treatment toxicity. Median survival for patients with recurrent disease versus primary disease was 3.0 years versus 1.3 years (P < 0.05), with a delay of metastatic failure in patients with recurrent tumors (P = 0.06). At 3 years, distant metastatic failure was 79%, local failure was 10%, and regional failure was 15%. IORT for locally advanced primary or recurrent gastric malignancies effectively decreases the risk of local failure. For patients with isolated local recurrences, IORT may be effective salvage therapy. However, more effective systemic therapy is needed as a component of treatment.

Evaluation of intraoperative radiotherapy for gastric carcinoma with D2 and D3 surgical resection

AIM: To study the proper sites and doses of intraoperative radiotherapy (IORT) for gastric carcinoma and the effects of this treatment.

METHODS: A total of 106 patients with stageI-IV gastric carcinoma who received D2 or D3 radical operation combined with IORT were analyzed. Sixty-seven patients with gastric cancer of the antrum and body underwent distal gastrectomy. The sites of irradiation were at the celiac artery and hepatoduodenal ligment area. Another 39 patients with carcinoma of the cardia and upper part of the gastric body and whole stomach underwent proximal gastrectomy or total gastrectomy. The sites of irradiation for this group were the upper margin of the pancreas and the regional para-aorta. The therapeutic effects (including survival and complications) of these 106 cases received operation combined with IORT (IORT group) were compared with 441 cases treated during the same time period by a radical operation alone (operation group).

RESULTS: The radiation dose below 30 Gy was safe. The therapeutic method of the operation combined with IORT did not prolong the survival of patients with stage I and IV gastric cancer, but the 5-year survival rates of patients with stage II and III gastric cancers were significantly improved. The 5-year survival rates of the stages III cancer patients receiving D2 resection combined with IORT were markedly improved, while for those receiving D3 radical resection, only the postoperative 3- or 4-year survival rates were improved (P < 0.005-0.001). The 5-year survival rate for those patients was raised only by 4.7% (P > 0.05).

CONCLUSION: The 5-year survival rates of patients with stages II and III gastric carcinoma who received D2 lymphadenectomy combined with IORT were improved, and there was no influence on the postoperative complications and mortality.

Intraoperative radiotherapy in the multimodality approach to gastric cancer

It is difficult to conclude a clear benefit from the addition of IORT to the multimodality treatment of gastric cancer based on the studies available. Only three prospective randomized trials have been published and each varies in the approach of combining adjuvant and neoadjuvant chemotherapy and EBRT with IORT. With a complex degree of confounding factors in these and other retrospective series, it also remains difficult to identify a decrease in local recurrence rates, or an improvement in overall patient survival rates attributable to the use of IORT. Several series, however, have identified patient subsets--specifically, patients who have advanced disease with serosal extension or node-positive disease--who may be more likely to benefit from the addition of IORT to gastric resection. Finally, there is no evidence in prospective or retrospective series that there is an increased patient risk or inferior outcome caused by the addition of IORT. Limited evidence of a possible benefit in advanced disease and no evidence of a disadvantage to the use of IORT have promoted continued use and investigation in the multimodality treatment of an aggressive disease. Continued efforts in prospective randomized trials should be promoted to further delineate the efficacy of IORT and EBRT in the treatment of gastric cancer, especially in light of recently published data [30], where concurrent chemotherapy has been reported to increase survival rates in high-risk patients.

Curative treatment of gastric cancer: towards a multidisciplinary approach?

Despite marked decreases in incidence over the last century, particularly in developed countries, gastric cancer is still the second-most common tumor worldwide. Surgery remains the gold standard for the cure of locoregional disease. However, in most countries, the diagnosis is made at an advanced stage, and the 5-year survival for surgically resectable disease stays far below 50%. The efficacy of chemotherapy and/or radiation therapy in addition to surgery has been actively studied over the last 30 years. Unfortunately, with few exceptions, most studies of adjuvant therapy in gastric cancer have given deceiving results. The purpose of this review is to address the reasons for our failure to objectivate an improvement in the cure of gastric cancer with adjuvant treatment in most trials, and to consider potential solutions. The low efficacy of chemotherapy regimens available up to now may have hampered our progress. In addition, many previous studies suffered limitations of design or methodology (e.g. low accrual, inadequate disease stage selection, inadequate surgical treatment) that may have obscured a treatment effect. Furthermore, the reduced treatment tolerance of post-gastrectomy patients, perhaps due to their poor nutritional status, results in decreased or delayed adjuvant systemic therapy, with potential adverse consequences in its efficacy. Among potential solutions, the arrival of new drugs, taxanes and topoisomerase I inhibitors in particular, which have shown encouraging results in metastatic disease, may increase the impact of chemotherapy in a multidisciplinary treatment approach. Pre-treatment with chemotherapy and/or radiation therapy prior to surgery may also be advantageous, averting the problems associated with post-surgical treatment. Such an approach has been shown to be feasible in phase II studies, and is relatively well tolerated by patients. Several carefully designed randomized phase III trials are underway to answer this question.

Intraoperative radiotherapy: current thinking

Intraoperative radiotherapy (IORT) refers to the delivery of irradiation at surgery. A large single dose of irradiation is delivered to a surgically defined area, while uninvolved and dose-limiting tissues are displaced, the final goal of IORT being enhanced locoregional tumour control. IORT is used in most modern protocol studies as a boost radiation component of multidisciplinary treatment approaches. More recently, high activity radiation sources or mobile operating room treatment machines are used to facilitate the IORT procedure. Clinical experiences have shown that IORT may improve local control and disease-free survival, especially when used in adjuvant setting, combined with external beam irradiation in some neoplasms such as cancer of the stomach, pancreas, colorectum, and soft tissue sarcoma.

Intraoperative radiotherapy for gastrointestinal cancer

Local recurrence following potentially curative tumor resection is a major problem in patients with gastrointestinal cancer. To augment surgical excision and to avoid the disadvantages of external beam irradiation, intraoperative radiotherapy (IORT) has been applied to primary and recurrent gastrointestinal cancer, both with curative intent and for palliation. There is ample evidence that the combination of radical surgery and IORT can improve local control. Whether this eventually can translate into improved overall survival has not yet been studied in adequately powered randomized and controlled trials.

A prospective, randomized trial of pre-operative and intraoperative radiotherapy versus surgery alone in resectable gastric cancer

INTRODUCTION

Worldwide, gastric cancer remains one of the most common malignancies. Discouraging survival rates after surgical treatment promote the study of adjuvant therapy. A prospectively, randomized, controlled clinical trial was performed in order to determine whether pre-operative and intraoperative radiotherapy improves treatment results of gastrectomy for stomach carcinoma.

METHODS

From 1993 to 1998, 112 patients were randomized and underwent exploratory laparotomy; among them 78 satisfied protocol requirements and entered in the trial. Patients in the experimental group were treated with pre-operative radiotherapy (20 Gy/5 days), gastrectomy and intraoperative radiotherapy (20 Gy using 8-12 electrons). Patients in the control group underwent surgery alone.

RESULTS

Incidence and distribution of post-operative complications were similar in both groups except significantly higher incidence of pancreatitis after surgical treatment. No late radiation-related morbidity was registered. There was no significant difference in survival between the two treatment groups (Chi(2)=1.026, df=1, P=0. 311) as well as in N0 (Chi(2)=0.0029, df=1, P=0.956) and T1-2 subgroups (Chi(2)=0.1928, df=1, P=0.660). In contrast, combined treatment had marked survival advantage in more advanced stages: in the case of lymph-node involvement (Chi(2)=4.19, df=1, P=0.04) and extragastric tumour extension (Chi(2)=4.118, df=1, P=0.042).

CONCLUSION

The proposed intensive treatment programme is feasible, shows good acute and late tolerance and has the potential to improve survival in patients with locally advanced gastric cancer.

[Stomach adenocarcinoma. Evolution of surgical treatment in a series of 350 cases]

STUDY AIM

The aim of this prospective study was to evaluate, in a series of 350 gastric adenocarcinomas, the evolution of their clinical and histological features and the evolution of their surgical management.

PATIENTS AND METHODS

From 1970 to 1996, 350 patients with gastric carcinoma (cardiac cancer excluded) were operated on in the same center. Mean age was 68.8 years and the sex ratio 1:4. These patients were divided into three groups which were analysed and compared (group 1 operated on between 1970 and 1988, group 2 between 1979 and 1987, group 3 between 1988 and 1996).

RESULTS

Antropyloric cancer was the most common (56% in group 3). Tumor size decreased but there were in group 3 more undifferentiated tumors (54.2%) and more tumors with lymph node involvement (72%). Stage III and IV tumors were still common (70% in group 3) and early gastric cancer incidence very low (9.9%). After 1980, surgical management was more radical, with more total gastrectomies and larger lymph node dissections. Adjuvant intraoperative and postoperative radiotherapy has been associated since 1985. Postoperative mortality rate decreased (13.8% in group 1 vs 6.1% in group 3) (P = 0.04) as did the postoperative morbidity rate (31.8% in group 1 vs 17.5% in group 3). The five-year actuarial survival rate was respectively 18.9% and 39.2% for groups 1 and 2 (P = 0.003); it was respectively 59.8% and 43.6% for all patients treated by adjuvant radiotherapy and for those with lymph node involvement.

CONCLUSION

Prognosis of gastric adenocarcinoma is still poor. A more radical surgical treatment did not increase the postoperative morbidity rate, but increased the survival rate. New adjuvant treatments including radiotherapy have to be evaluated in order to improve the prognosis.

[Intraoperative radiotherapy in 1997]

Intra Operative Radiation Therapy (IORT) has been routinely used for the past 20 years. It is a feasible treatment, with a reasonable cost and an acceptable acute and late toxicity. There is so far no strong randomized trial demonstrating that IORT can improve overall survival. Nevertheless, in many institutions it is recognized as an efficient treatment in selected patients. In case of locally recurrent disease an incomplete gross resection is often the only choice; IORT in such a situation has led to very encouraging results. For locally advanced deep seated primary tumors IORT seems to improve local control. In the near future IORT should be used on a larger and stronger basis. The manufacturing of new mobile linac should allow more surgeons to perform IORT and to conduct clinical trials to confirm the present indications in cancers with high local malignancy.

Intraoperative radiation therapy combined with limited lymph node resection in gastric cancer: an alternative to extended dissection?

PURPOSE

To describe the results of a series of 63 Western patients presenting with gastric adenocarcinoma and treated with surgery and intraoperative radiation therapy (IORT) over a 8-year period and to discuss the role of IORT when combined with limited lymph node dissection.

METHODS AND MATERIALS

From 1986 to 1993, 63 patients with gastric adenocarcinoma have been operated in the department of radiation oncology of the Hospices Civils de Lyon. The stage was: I in 17, II in 11, IIIA in 9, IIIB in 20, and IV in 6. The lymph node dissection was considered to be limited in 56 patients and extended in 7. The IORT dose ranged from 12 to 23 Gy (median: 15). Thirty patients also underwent a postoperative external beam irradiation with a standard dose of 44-46 Gy.

RESULTS

The postoperative mortality rate was 4.8%. The 5-year overall survival in the entire series was 47% and was 82, 55, 78, 20, and 0% in Stages I, II, IIIA, IIIB, and IV, respectively. Loco-regional relapse occurred in 15 of 63 patients and metastases in 15 of 63.

CONCLUSION

In Western patients treated by gastrectomy for adenocarcinoma of the stomach, IORT combined with limited lymph node dissection may provide overall survival similar to that observed after gastrectomy with extended lymph node dissection but with less postoperative mortality.