Comparison of mammographic findings after intraoperative radiotherapy or external beam whole breast radiotherapy

Background

The TARGIT (TARGeted Intraoperative Radiotherapy) trial was designed to compare local recurrence and complication rates in breast cancer patients, prospectively randomised to either EBRT (external beam whole breast radiotherapy) or a single dose of IORT (intraoperative radiotherapy). The aim of our study was to compare follow-up mammographic findings, ultrasound and biopsy rates in each group.

Methods

Follow-up imaging and breast biopsies of women from one centre participating in the TARGIT-A trial were independently reviewed by two radiologists blinded to the radiotherapy treatment received.

Results

The cohort consisted of 141 patients (EBRT n = 80/IORT n = 61). There was no significant difference in the patient or disease characteristics of the two groups. The number of follow-up mammograms and length of follow-up was similar (EBRT/IORT n = 2.0/2.4; 4.3yr/5.1yr; p = 0.386 χ² test). There were no significant differences in mammographic scar or calcification appearances of the post-operative site. Generalised increase in breast density and skin thickening were more common in the EBRT compared to the IORT group (p = 0.002; p = 0.030, χ² test respectively). A trend towards additional ultrasound at follow-up was observed in the IORT group (15 of 61 [24.6%] versus 11 of 80 [13.8%]), however this was not statistically significant (p = 0.100 χ² test). No disease recurrence was demonstrated on any of the breast biopsies taken. Only one biopsy was reported as fat necrosis in the IORT group.

Conclusions

Mammographic changes were more common following EBRT, although more additional follow-up ultrasounds were performed in the IORT group. IORT is not detrimental to subsequent radiological follow up.     

Preoperative Predictive Factors of Positive Margin Status After Breast Conserving Therapy (BCT) with Intraoperative Radiation Therapy (IORT): A Retrospective Study of 400 Patients

IntroductionSingle-fraction intraoperative radiation therapy (IORT) has emerged as a therapeutic option in patients undergoing breast conserving therapy (BCT) for early stage breast cancer, often eliminating the need for postoperative external beam radiation therapy. However, if a positive margin is encountered after BCT, the patient will ultimately require external beam radiation therapy. The purpose of this study was to identify preoperative factors from patient demographics, preoperative workup, or biopsy results that may be predictive of postoperative margin status.Materials and MethodsA retrospective chart review was performed on 396 patients who underwent BCT with IORT. Logistic regression models were utilized for statistical analysis.ResultsThe majority of studied variables were similar; however, differences were noted for high-grade tumors, in situ status, and progesterone receptor-negative (PR⁻) tumors. Grade 3 tumors were significantly associated with positive margin status when compared with Grade 1 (odds ratio, 2.30; P = .036). PR⁻ status tumors were found to be approximately 2 times more likely to have a positive margin (P = .028). Patients with in situ (stage 0) status tumors were 1.986 times more likely to have positive margins when compared with those with an invasive tumor (P = .030).ConclusionsHigher grade PR⁻ tumors are at increased risk of having a positive margin, which should be taken into consideration when considering treatment with IORT.     

Intraoperative radiation therapy at the National Cancer Institute: technical innovations and dosimetry

The technical complexity of intraoperative radiotherapy (IORT) requires modification of the standard physical and dosimetric methods used in external electron beam therapy. At the National Cancer Institute, a number of technical innovations have been integrated into ongoing clinical studies of IORT. These include: (1) an electron beam applicator system that is significantly different from other IORT systems and includes customized "squircle" applicators; (2) peripheral dose shields; (3) a modified surgical table replacing the standard radiation treatment couch; and (4) routine use of multiple IORT fields that necessitates field matching. The IORT applicator system and related devices and techniques are dosimetrically characterized in detail both for use in the IORT program and in order to illustrate many useful facets of electron dosimetry.     

术中和体外照射治疗晚期胰腺癌

目的 :分析不能手术切除的晚期胰腺癌术中放射 (IORT)和体外放射 (EBRT)治疗的疗效。方法 :回顾我院 1987- 1999年 75例不能手术切除的晚期胰腺癌患者进行单纯IORT、单纯EBRT和IORT加EBRT治疗的临床资料。结果 :单纯IORT、单纯EBRT和IORT加EBRT治疗的 1年生存率分别为15 2 %、14 3%和 31 8% ,IORT加EBRT治疗的结果优于前两者 ,P <0 0 5。结论 :IORT加EBRT治疗可以延长晚期胰腺癌患者的生存期     

Significance of intraoperative radiation therapy and high cumulative radiation doses in retroperitoneal soft tissue sarcoma

IntroductionIn retroperitoneal soft tissue sarcoma (STS) local recurrence (LR) rates remain high despite more aggressive surgical approaches. Since wide resection margins cannot be achieved in all patients, application of intraoperative radiation therapy (IORT) has been frequently discussed. Still, the significance of IORT in multimodal treatment of retroperitoneal STS remains unclear.Material and methodsPatients undergoing resection of primary or recurrent retroperitoneal STS at the University of Heidelberg Department of General, Visceral and Transplantation Surgery were retrospectively analyzed. Univariate Kaplan-Meyer and multivariate Cox regression analyses were performed to identify predictors of LR-free survival and to investigate the impact of IORT and high cumulative radiation doses. Analyses with propensity-score matched subgroups for IORT and cumulative radiation dose were performed to control for selection bias. Subgroup analyses for patients with retroperitoneal liposarcoma were likewise performed.Results272 patients were identified. Recurrent tumors, histology of dedifferentiated liposarcoma or unclassified sarcoma and microscopically incomplete resection were associated with decreased LR-free survival. In liposarcoma, only recurrent and dedifferentiated tumors were confirmed as poor prognostic factors concerning LR. IORT and cumulative radiation doses exceeding 60 Gy did not influence LR rates (estimated 5-year LR-free survival: IORT: 39%, non-IORT: 46%; p = 0.79).ConclusionIn this retrospective evaluation, additional application of IORT does not significantly influence oncological outcome in retroperitoneal soft tissue sarcoma. Randomized trials are needed to clarify the benefit of IORT.     

Response of aorta and branch arteries to experimental intraoperative irradiation

Injury to the aorta was evaluated in dogs 2 and 5 years after fractionated irradiation (EBRT), intraoperative irradiation (IORT) or a combination. Doses greater than 20 Gy IORT combined with 50 Gy EBRT given in 2 Gy fractions or 30 Gy IORT alone were accompanied by a significant risk of aneurysms or large thrombi as determined at necropsy 4 to 5 years following irradiation. Narrowing of the aorta as detected by aortography occurred at 5 years but was not detected earlier. The ED50 for aortic narrowing was 38.8 Gy IORT and 31 Gy IORT plus 50 Gy EBRT. The ED50 for branch artery injury was 24.8 Gy IORT alone and 19.4 Gy IORT plus 50 Gy EBRT. The difference in ED50s for IORT alone and IORT plus EBRT indicates that the contribution of the EBRT dose in terms of an IORT dose for aortic narrowing was 7.8 Gy and for branch artery injury was 5.4 Gy. The ED50 for incidence of small thrombi in the aorta was about 29 Gy for IORT alone and 23.5 Gy for IORT combined with EBRT. Fibrous thickening of the adventitia was measured and the effect of the 50 Gy EBRT component of a combination of EBRT and IORT was determined to be equivalent to 10 to 12 Gy IORT. Based on the various estimates, IORT doses of 10-15 Gy have an effect of 5 times or greater the amount given in 2 Gy fractions. At all EBRT doses and at lower IORT doses the intima was greatly thickened. At IORT doses of 20 Gy or above there was a dose related decrease in intimal thickness to near normal values. This was probably due to cell killing or inhibition of intimal proliferation that predominated at higher doses. Although the risk of serious vascular complications appears low following IORT of humans, this may be due to short observation times and the fact that IORT doses currently used are usually 20 Gy or less; this may be near the tolerance for late response of larger arteries. Only one dog in this study had complete rupture of the aorta causing death. Five other dogs at high IORT doses had near ruptures of the aorta but were clinically normal.     

Efficacy and safety of intraoperative radiotherapy in breast cancer: a systematic review

The objective of this study is to assess the efficacy and safety of intraoperative radiotherapy (IORT) for early breast cancer through a systematic review. Fifteen studies met the inclusion criteria. Most studies assessed the combined treatment with IORT (10-24 Gy) and external beam radiotherapy (EBRT) (45-50 Gy) on early stage breast cancer (T_0-2). Local control was over 95% for 1 and 4 years of follow-up and the 5-year overall survival was 99%. The TARGIT-A study found a similar survival comparing IORT with standard treatment. The incidence of acute and chronic complications was scarce. IORT is well tolerated by patients and acute and late toxicities are low. There are no differences in survival for IORT treated patients versus standard treatment.     

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.     

Definitive intraoperative radiotherapy for musculoskeletal sarcomas and malignant lymphoma in combination with surgical excision

Background. The purpose was to estimate retrospectively the outcome of patients with musculoskeletal sarcoma or malignant lymphoma treated with intraoperative radiotherapy (IORT).Methods. Between 1988 and 1999, definitive IORT in combination with surgical excision was performed in 24 patients with musculoskeletal sarcoma (malignant fibrous histiocytoma, 10; osteosarcoma, 6; liposarcoma, 2; chondrosarcoma, 1; synovial sarcoma, 1; Ewing's sarcoma, 1; angiosarcoma, 1; epithelioid sarcoma, 1; malignant schwannoma, 1) and 3 patients with malignant lymphoma. The tumor was excised by marginal margin excision, intralesional margin excision, or wide margin excision; 15–45Gy electrons was then delivered to the affected sites.Results. In the 8 patients without distant metastases at the first visit, 4 patients are alive 6.5–11.5 years after IORT, and 4 patients died <4.5 years after IORT. The incidence of local recurrence was 13%. In the 19 patients with distant metastases at the first visit, 3 patients are alive 2.5–6.7 years after IORT, and 16 patients died 0.2–5.7 years after IORT. The incidence of local recurrence was 45%. Complications after IORT were found in 5 patients: neuropathy, 1 patient; skin necrosis, 1 patient; myelopathy, 1 patient; enteritis ileus, 1 patient; and edema, 1 patient.Conclusion. IORT with a radiation dose of 15–45Gy in combination with surgical excision appeared to be useful for local control and to be more effective in patients without distant metastases at the first visit than in patients with distant metastases.     

History, preliminary results, complications, and future prospects of intraoperative radiotherapy

Intraoperative electron beam radiotherapy (IORT) is a new combined modality therapy in the treatment of cancer. IORT is delivered during a surgical procedure to a tumor or tumor bed and areas of possible local regional spread, with the ability to shield or physically move normal tissues and organs out of the treatment volume. IORT is feasible for various intraabdominal, retroperitoneal, pelvic, and other malignancies. It is possible to increase the total radiation dose, thereby improving the therapeutic ratio; a better local control without an increasing morbidity. Although the optimum use of IORT is still unknown, it is believed that its greatest value is in combination with maximal surgical resection of the tumor with or without external beam radiotherapy (EBRT). IORT is still an experimental treatment modality combining surgery, EBRT, and if necessary, chemotherapy. Because IORT is an expensive treatment method, it is important to determine which method is the best and most convenient for the patient. The answer can be given only when prospective, randomized clinical IORT trials and cost-effectiveness studies are initiated.     

Phase I study of intraoperative radiotherapy with photon radiosurgery system in children with recurrent brain tumors: preliminary report of first dose level (10 Gy)

PURPOSE: To describe the preliminary results after intraoperative radiotherapy (IORT) with the photon radiosurgery system in children with recurrent brain tumors treated at the first dose level (10 Gy) of a Phase I protocol. METHODS AND MATERIALS: A Phase I IORT dose escalation protocol was initiated at Children's Memorial Hospital to determine the maximal tolerated IORT dose in children with recurrent brain tumors. RESULTS: Fourteen children have received IORT thus far. Eight had been previously irradiated. Thirteen children had ependymoma. The median follow-up was 16 months. Three patients (21%) developed radiation necrosis on follow-up MRI scans 6 to 12 months after IORT. They had not been previously irradiated and had received 10 Gy to a depth of 5 mm. One required surgery and the other two had resolution of their lesions without treatment. All 3 patients were asymptomatic at the last follow-up. No other late toxicity was observed at the last follow-up visit. Eight patients (57%) had tumor control within the surgical bed after IORT. CONCLUSION: Our findings have demonstrated the safety and feasibility of IORT to a dose of 10 Gy to 2 mm in children with previously irradiated brain tumors. IORT to a dose of 10 Gy at 5 mm was associated with a greater complication rate.     

Analysis of failure following curative irradiation of gallbladder and extrahepatic bile duct carcinoma

Twenty patients with carcinoma of the gallbladder (GB-4 patients) or extrahepatic bile ducts (EHBD-16 patients) received radiation therapy with curative intent between January, 1980 and December, 1982. All 20 received 4500–5000 rad in 180–200 rad fractions to the tumor and regional lymph nodes. A 1000 to 1500 rad external beam boost was delivered in 180–200 rad fractions in 10 patients who received external beam alone or concomitant 5-Fluorouracil (5-FU). Three of the four GB and 5 of the 16 EHBD patients received a transcatheter boost with 192-Iridium (¹⁹²Ir) to a dose of 2000–2500 rad calculated at a 0.5-0.1 cm radius. An additional 2 patients with EHBD lesions received an intraoperative electron (IORT) boost of 1500–2000 rad in one fraction calculated to the 90% isodose. Survival and patterns of failure were analyzed by site and treatment method. All four patients with GB carcinoma are dead of disease at 5$\text{1}\text{2}$, 6, 9 and 10 months from the date of diagnosis respectively. Three of the four developed diffuse peritoneal carcinomatosis. Five of the 16 patients with EHBD carcinoma are alive with a median follow-up of 18 months (range 6–23 months). Four of the 5 patients received a transcatheter ¹⁹²Ir or IORT boost and all are without evidence of disease. Four of 9 patients who had a subtotal resection with transection of tumor, dilatation of the bile ducts with probes or curettement of the bile ducts developed either diffuse peritoneal carcinomatosis (3 patients) or a recurrence in the surgical scar (2 patients). Local failure was documented in 3 of the nine patients treated with external beam alone ±5-FU, and has been documented in one of the seven patients who received an IORT or transcatheter ¹⁹²Ir boost. Further experience is necessary to determine whether this aggressive treatment will result in long-term disease-free survival in these patients.     

Intraoperative Radiotherapy with Balloon-Based Electronic Brachytherapy System—A Systematic Review and First Bulgarian Experience in Breast Cancer Patients

(1) Background: We aimed to analyze currently available studies with intraoperative radiotherapy (IORT) as a choice of treatment where the Xoft Axxent^® electronic brachytherapy (eBx) system was used as a single-dose irradiation and an exclusive radiotherapy approach at the time of surgery in patients with early breast cancer (EBC). We also compared the results of the systematic review to the Bulgarian experience. (2) Methods and Materials: We performed a systematic review of the studies published before February 2021, which investigate the application of a single-fraction 20 Gy radiation treatment, delivered at the time of lumpectomy in EBC patients with the Xoft Axxent^® eBx System. A systematic search in PubMed, Scopus, and ScienceDirect was performed. The results are reported following the PRISMA guidelines. The criteria on patients’ selection for IORT (the additional need for EBRT), cosmetic outcomes, and recurrence rate from the eligible studies are compared to the treatment results in Bulgarian patients. (3) Results: We searched through 1032 results to find 17 eligible studies. There are no published outcomes from randomized trials. When reported, the cosmetic outcomes in most of the studies are defined as excellent. The observed recurrence rate is low (1–5.8%). Still, the number of patients additionally referred to postoperative external breast radiotherapy (EBRT) is up to 31%. Amongst the 20 patients treated in Bulgaria, the cosmetic outcomes are also evaluated as excellent, five of which (25%) are referred for EBRT. Within median follow-up of 39 months, there was one local and one distal recurrence. (4) Conclusions: Current evidence demonstrates the Xoft Axxent^® eBx system as a safe and feasible technique for IORT delivery in EBC patients. There are no randomized controlled trials conducted at this time point to prove its long-term effectiveness. Better patient selection and a reimbursement strategy have to be proposed to extend the application of this technique in Bulgaria.     

The Role of Intraoperative Radiation in Early-stage Breast Cancer

Intraoperative radiation therapy (IORT) is a specialized form of accelerated partial breast irradiation in which a single dose of radiation is delivered to the tumor bed at the time of breast conserving surgery. With completion of radiation to the tumor bed at the time of surgery, IORT promises improved patient convenience, compliance, and quality of life. In addition, with its potentially skin-sparing properties and ability to deliver a high biologically effective dose to the tumor bed while reducing dose to nontarget tissues, IORT results in different but overall less toxicities compared with other modalities of radiation for breast cancer. However, skepticism over the role of IORT in breast cancer exists, and the 2 randomized trials that have analyzed IORT as the definitive radiation component of breast conservation therapy have shown an increase in local recurrence rates with IORT compared with whole breast irradiation, but similar rates of overall survival. In this review, we discuss the practicalities of IORT, the prospective data supporting and negating the role of IORT in lieu of whole breast irradiation, and the toxicity after IORT in early-stage breast cancer. We also review the role of IORT as a radiation boost and specific strategies for successful implementation of IORT in breast cancer.     

High-dose intraoperative radiotherapy for unresectable pancreatic cancer

PURPOSE: The results of high-dose intraoperative radiotherapy (IORT) and/or external beam radiotherapy (EBRT) for unresectable pancreatic cancer were analyzed to evaluate the possible advantages of IORT in combination with EBRT. METHODS AND MATERIALS: Between 1983 and 1993, 115 patients with unresectable adenocarcinoma of the pancreas (53 with non-Stage IV disease and 62 with Stage IV disease) were treated with EBRT + IORT (55 patients), EBRT alone (44 patients), or IORT alone (16 patients). In non-Stage IV patients, the use of EBRT alone was due to the unavailability of IORT and the use of IORT alone was due to refusal of EBRT. The IORT dose was 30-33 Gy and the EBRT dose was 40-60 Gy. A historical control group comprised of 101 patients undergoing palliative surgery alone was also analyzed. RESULTS: Both non-Stage IV and Stage IV patients receiving EBRT with or without IORT had a better prognosis than the nonirradiated historical controls. Among non-Stage IV patients, the median survival of the EBRT + IORT group (8.5 months) and the EBRT group (8 months) was similar, although survival from 12 to 18 months was higher in the former group (38% vs. 10% at 12 months, p = 0.018, and 19% vs. 0% at 18 months, p = 0.023). In Stage IV patients, the prognosis was not influenced by the type of radiotherapy. Multivariate analysis revealed that a pretreatment carbohydrate antigen (CA) 19-9 level < 1000 U/ml was associated with better survival. In non-Stage IV patients with a CA 19-9 level < 1000 U/ ml, EBRT + IORT appeared to produce a better survival than EBRT alone (p = 0.047). This was supported by multivariate analysis. CONCLUSION: High-dose IORT + EBRT may be more effective than EBRT alone in patients with unresectable but localized pancreatic cancer and a low CA 19-9 level.     

Late radiation toxicity after intraoperative radiotherapy (IORT) for breast cancer: results from the randomized phase III trial TARGIT A

The randomized phase III trial TARGIT A showed non-inferiority regarding local control after intraoperative radiotherapy (IORT 20 Gy which was followed by whole breast radiotherapy (WBRT) in patients with risk factors only) in comparison to standard WBRT (50–56 Gy) after breast-conserving surgery in selected patients. This is the first analysis of long-term toxicities in the setting of TARGIT. Between 02/2002 and 12/2008, 305 patients were treated within TARGIT A (Arm A: n = 34 IORT, n = 20 IORT + WBRT for risk factors; Arm B WBRT: n = 55) or received IORT as a planned boost (control group: n = 196) at a single center. Toxicity was assessed according to the LENT SOMA scales. No significant differences were seen between Arm A and Arm B regarding fibrosis, breast edema, retraction, ulceration, lymphedema, hyperpigmentation, and pain. Arm A had significantly less telangiectases compared to Arm B (p = 0.049). In the subanalysis (Arm A IORT vs. Arm A IORT + WBRT vs. Arm B), fibrosis had a cumulative rate of 5.9 versus 37.5 versus 18.4 %, respectively (38.2 % IORT boost control group), at 3 years. No telangiectases were seen after IORT alone (0 % Arm A IORT vs. 17.5 % Arm A IORT + WBRT vs. 17.7 % Arm B). The hazard ratio of higher grade toxicity as first event was 0.46 (95 % CI, 0.26–0.83) for Arm A IORT as compared to Arm B (p = 0.010). No recurrences were seen after a median follow-up of 40 months (Arm A) and 42 months (Arm B). With its very low chronic skin toxicity rates and outstanding long-term results regarding toxicity and local control, IORT with 50 kV X-rays is a safe and effective method for treatment of selected breast cancer patients.     

Intraoperative radiotherapy in colorectal cancer: Systematic review and meta-analysis of techniques,long-term outcomes,and complications

BackgroundThe precise contribution of IORT to the management of locally advanced and recurrent colorectal cancer (CRC) remains uncertain. We performed a systematic review and meta-analysis to assess the value of IORT in this setting.MethodsStudies published between 1965 and 2011 that reported outcomes after IORT for advanced or recurrent CRC were identified by an electronic literature search. Studies were assessed for methodological quality and design, and evaluated for technique of IORT delivery, oncological outcomes, and complications following IORT. Outcomes were analysed with fixed-effect and random-effect model meta-analyses and heterogeneity and publication bias examined.Results29 studies comprising 14 prospective and 15 retrospective studies met the inclusion criteria and were assessed, yielding a total of 3003 patients. The indication for IORT was locally advanced disease in 1792 patients and locally recurrent disease in 1211 patients. Despite heterogeneity in methodology and reporting practice, IORT is principally applied for the treatment of close or positive margins. When comparative studies were evaluated, a significant effect favouring improved local control (OR 0.22; 95% CI = 0.05–0.86; p = 0.03), disease free survival (HR 0.51; 95% CI = 0.31–0.85; p = 0.009), and overall survival (HR 0.33; 95% CI = 0.2–0.54; p = 0.001) was noted with no increase in total (OR 1.13; 95% CI = 0.77–1.65; p = 0.57), urologic (OR 1.35; 95% CI = 0.84–2.82; p = 0.47), or anastomotic complications (OR 0.94; 95% CI = 0.42–2.1; p = 0.98). Increased wound complications were noted after IORT (OR 1.86; 95% CI = 1.03–3.38; p = 0.049).ConclusionsDespite methodological weaknesses in the studies evaluated, our results suggest that IORT may improve oncological outcomes in advanced and recurrent CRC.     

Patterns of local recurrence in locally advanced rectal cancer after intra-operative radiotherapy containing multimodality treatment

Background and purpose

The purpose of this study is to analyze the patterns of local recurrence (LR) after intra-operative radiotherapy (IORT) containing multimodality treatment of locally advanced rectal carcinoma (LARC).

Methods and materials

Two hundred and ninety patients with LARC who underwent multimodality treatment between 1994 and 2006 were studied. For patients who developed LR, the subsite was classified into presacral, postero-lateral, lateral, anterior, anastomotic or perineal. Patient and treatment characteristics were related to subsite of LR.

Results

After 5 years, 34 patients (13.2%) developed LR. The most prominent subsite of LR was the presacral subsite. 47% of the local recurrences occurred outside the IORT field. Most recurrences developed when IORT was given dorsally, while least occurred when IORT was given ventrally. Especially after dorsal IORT a high amount of infield recurrences were observed (6 of 8; 75%). In multi-variate analysis tumor distance of more than 5 cm from the anal verge and a positive circumferential margin were associated with presacral local recurrence.

Conclusions

Multimodality treatment is effective in the prevention of local recurrence in LARC. IORT application to the area most at risk is feasible and seems effective in the prevention of local recurrence. Dorsal tumor location results in unfavourable oncologic results.     

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.     

Intra-operative radiation therapy in tumors of the digestive tract

All the retrospective and prospective studies concerning IORT in tumors of the digestive tract tend to substantiate a significant improvement in local control without a significant increase in survival. Improvements in the results of IORT can be expected in the near future, and may occur on several fronts: - Technological improvements: advances in the development of IORT machines, with the construction of electron accelerators specifically designed for IORT; greater precision in the systems of collimation (asymmetric collimator, multiple leaves, computerization of the control of collimation); and increased adaptability of the localizers to each clinical situation and to each patients. - Increase in the biological effects of IORT: determination of the exact role of IORT in relation to other therapeutic methods, its integration into the global therapeutic strategy for cancer, and the optimization of IORT doses should all be studied in phase II and III trials. Interesting results are expected from the combination of different methods of preoperative, intraoperative, and postoperative radiotherapy with chemotherapy; the cumulative effect of radiosensitization and cytotoxicity can bring about both local control and treatment of the general disease. In addition, the combination of hypoxic cell radiosensitizers and IORT, a source of important cellular hypoxia as a result of single doses, appears promising. - Lastly, randomized studies in a larger number of patients with objectives and methodologies to be perfected will document the actual contribution of IORT to an increase in survival as part of an overall treatment strategy for digestive tumors. At present, the prognosis remains significantly related to systemic metastatic evolution; this can only be influenced by chemotherapy, whose efficacy remains to be demonstrated. As means for better control of systemic disease are discovered, the clear benefits of local control via IORT will assume increased importance.