Effect on local control and survival of electron beam intraoperative irradiation for resectable pancreatic adenocarcinoma

PURPOSE: To assess the impact on local control and survival of intraoperative radiotherapy (IORT) in resectable pancreatic adenocarcinoma. METHODS AND MATERIALS: The outcome of 127 patients surgically treated with curative intent combined with IORT was compared with the therapeutic results of 76 patients treated with surgery as exclusive treatment. RESULTS: Operative mortality and morbidity were similar in IORT and no-IORT patients. In 49 patients with locally limited disease (Stage I-II; LLD), IORT (n = 30) reduced the local failure rate and significantly prolonged time to local failure (TTLF), time to failure (TTF), and overall survival (OS) with respect to surgery alone (n = 19). The multivariate analyses, stratifying patients by age, tumor grade, resection margins, chemotherapy, and external-beam radiotherapy use, confirmed the independent impact of IORT on outcome.In patients with locally advanced disease (Stage III-IVA; LAD), IORT had an impact on local failure rate and on TTLF when combined with beam energies of greater than 6 MeV, whereas no effect on TTF and OS was observed. CONCLUSION: IORT did not increase operative mortality and morbidity and achieved a significant improvement in local control and outcome in patients with LLD. In patients with LAD, beam energies greater than 6 MeV prolonged TTLF.     

Intraoperative radiotherapy for recurrent and/or residual colorectal cancer

Intraoperative radiotherapy (IORT) is an attractive boosting modality in the combined treatment of recurrent and/or residual colorectal cancer. Twenty seven patients treated with IORT are analysed. Residual disease following resection of the primary tumor was treated in 11 cases (group I). Localized recurrent disease without previous radiotherapy was treated in 11 cases (group II). IORT was used in five additional patients with local recurrences in previously irradiated areas (group III). The treatment program consisted of maximal tumor resection, IORT (10-30 Gy) to the area of residual disease and external beam radiotherapy (46-50 Gy). The median follow-up time for the entire series of patients is 11 months. Local tumor control rates are 90% in group I, 63% in group II and 60% in group III. Toxicity and complications related to IORT observed in this initial experience have been pelvic pain (29%) and lower extremity neuropathy (3%). These early clinical results suggest that the IORT combined with surgery and external beam radiotherapy is feasible in primary and recurrent disease. Local control rates obtained in patients not suitable for curative surgery are encouraging.     

Long-term outcome and toxicities of intraoperative radiotherapy for high-risk neuroblastoma

PURPOSE: To review a historical cohort of consecutively accrued patients with high-risk neuroblastoma treated with intraoperative radiotherapy (IORT) to determine the therapeutic effect and late complications of this treatment. METHODS AND MATERIALS: Between 1986 and 2002, 31 patients with newly diagnosed high-risk neuroblastoma were treated with IORT as part of multimodality therapy. Their medical records were reviewed to determine the outcome and complications. Kaplan-Meier probability estimates of local control, progression-free survival, and overall survival at 36 months after diagnosis were recorded. RESULTS: Intraoperative radiotherapy to the primary site and associated lymph nodes achieved excellent local control at a median follow-up of 44 months. The 3-year estimate of the local recurrence rate was 15%, less than that of most previously published series. Only 1 of 22 patients who had undergone gross total resection developed recurrence at the primary tumor site. The 3-year estimate of local control, progression-free survival, and overall survival was 85%, 47%, and 60%, respectively. Side effects attributable to either the disease process or multimodality treatment were observed in 7 patients who developed either hypertension or vascular stenosis. These late complications resulted in the death of 2 patients. CONCLUSIONS: Intraoperative radiotherapy at the time of primary resection offers effective local control in patients with high-risk neuroblastoma. Compared with historical controls, IORT achieved comparable control and survival rates while avoiding many side effects associated with external beam radiotherapy in young children. Although complications were observed, additional analysis is needed to determine the relative contributions of the disease process and specific components of the multimodality treatment to these adverse events.     

Intraoperative radiation therapy for high-risk pediatric neuroblastoma

PURPOSE: To evaluate the efficacy of intraoperative radiation therapy (IORT) in the treatment of high-risk pediatric neuroblastoma. METHODS AND MATERIALS: Between 1986 and 1998, 23 children received IORT for pediatric neuroblastoma. Electron beam energies ranged from 4 MeV to 16 MeV and median dose was 10 Gy (7-16 Gy). RESULTS: Twenty-one of 23 patients were classified as high-risk. A gross total resection (GTR) was achieved in 18 patients, of whom 6 experienced disease recurrence, 2 of which included a locoregional relapse as a component of failure. Fourteen of 18 patients receiving IORT after a GTR are disease-free survivors. A second subset of 5 patients had a subtotal resection (STR), with gross residual disease remaining after surgery. All 5 patients recurred locally, and all died of their disease. IORT was extremely well-tolerated in our cohort. Surgical resection and IORT resulted in the narrowing of the abdominal aorta and an atrophic kidney in 1 patient. CONCLUSIONS: For high-risk neuroblastoma patients, IORT as the only radiotherapy to the primary, produced excellent local control after a GTR. However, IORT as the sole radiotherapy to the primary was inadequate for patients with extensive adenopathy or an STR. In this setting, we are exploring the use of IORT as a boost in conjunction with external beam radiation therapy.     

Intraoperative radiotherapy in the multimodality approach to colorectal cancer

The addition of intraoperative radiotherapy (IORT) to the multimodality approach for the treatment of locally advanced and locally recurrent colorectal cancer seems to result in improvements in local control and long-term survival. Local control and survival are most likely in patients in whom a gross total resection is accomplished. Peripheral nerve is the dose-limiting structure for patients treated with IORT. Further improvements in local control require the addition of dose modifiers during external beam radiotherapy or IORT. Distant relapse remains problematic, and effective systemic therapy is necessary to significantly improve long-term survival.     

软组织肉瘤手术加术中放疗的临床研究

目的:探讨软组织肉瘤术中放疗的意义。方法:对39例软组织肉瘤患者行根治或姑息性手术,术中放疗在术中放疗手术室进行,术中根据肿瘤大小,选择不同术中放疗限光筒及6～12MeV电子线1次照射15～25Gy,姑息手术者剂量加大至36Gy。术后辅以外照射治疗,常规设野,5/周,2Gy/次,总量40～50Gy。初发病灶10例,术后复发29例。结果:39例患者随访12～64个月,3、5年局控率分别为71.8%和64.1%。3年生存率为82.0%。结论:术中放疗具有较高的局控率,比之其他治疗具有许多优点,将获得较高的生存率。     

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

Intraoperative radiotherapy (IORT) has been proposed as an encouraging treatment for colorectal cancer. The aim of this study is to assess the efficacy and safety of IORT for this cancer through a systematic review. Studies located in electronic databases were selected according to established criteria, read and analysed and the results extracted by two independent reviewers. Fifteen studies met the selection criteria. Five-to-six-year local control (LC) was over 80% and 5-year overall survival (OS) was close to 65%. For recurrences, the 5-year overall survival was 30%. The main acute complications were gastrointestinal. Adding IORT to conventional treatment reduces the incidence of local recurrences within the radiation area over 10%. IORT is a safe technique as it does not increase toxicity associated with conventional treatment.     

Pattern of failures in gastric cancer patients with lymph node involvement treated by surgery, intraoperative and external beam radiotherapy.

AIMS: High local failure rates in gastric cancer have been reported, up to 67%. To achieve a better local control, we evaluated intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT) in association with surgery for gastric cancer patients with lymph node involvement. We report here the analysis of the patterns of failure for patients involved in this IORT protocol. MATERIAL AND METHODS: Forty-two positive lymph node (N+) gastric cancer patients were operated on (31 total, three subtotal and eight extended gastrectomies) with IORT procedure between 1985 and 1997 (33 males, nine females, mean age 61.3 years). IORT was focused on coeliac area (mean dose 15 Gy), followed by EBRT (46 Gy) in 36 patients. Ten patients were pN1 and 32 were pN2. A concurrent systemic chemotherapy (five Fluoro-Uracil and Cisplatinum) was performed in 14 patients. RESULTS: One patient died postoperatively. Actuarial pN+ 10 year survival rate was 44.8%. The 5 year actuarial local control and disease-free survival rates were 78.8 and 47.5%, respectively. As far as patterns of failure were explored, 5 patients have a local coeliac recurrence (12%) and 12 have distant metastases with no evidence of coeliac recurrence. CONCLUSION: This retrospective analysis suggests a potential effect of IORT and/or EBRT in promoting local control and long-term survival in gastric cancer patients with lymph node involvement.     

Surgery with intraoperative radiotherapy for sarcomas of the pelvic girdle: A pilot experience

Sarcomas of the pelvic girdle represent difficult treatment problems. Many are not treatable for cure, and among the patients who are technically resectable, there is high risk for local tumor recurrence and distant spread. Intraoperative radiotherapy (IORT) has been used in conjunction with surgical resection in five patients with extensive sarcomas of the pelvic girdle. Patients underwent a hemipelvectomy and IORT (dose 20–30 Gy) to the sacral resection margin and surrounding soft tissues. Three patients developed pulmonary metastases within 3 months and eventually died from metastastic disease (8–38 months). Two patients have remained disease-free (43 and 53 months). Four patients (80%) have remained locally free of tumor with follow-ups of 8–53 months. The only treatment complication was late osteonecrosis of the coccyx which appeared 7 months after treatment. By contrast, six historical control patients with sarcomas of the pelvic girdle treated with resection alone showed a local control rate of only 27% over a 40-month follow-up. On the basis of this preliminary experience, it appears that IORT may substantially help to control local disease in patients with grossly resectable sarcomas of the bony pelvis.     

A Systematic Review of Intraoperative Radiotherapy in Early Breast Cancer

A systematic review was undertaken to assess the safety and efficacy of intraoperative radiotherapy (IORT) in early breast cancer compared with breast conserving surgery with postoperative radiotherapy. Literature databases were searched up to March 2002 inclusive. IORT studies of any design and breast conserving therapy randomised controlled trials with sample sizes greater than 500 patients (with at least one arm of breast conserving therapy (BCT)) and systematic reviews on BCT published since 1992, were included for comparison. Seven unique IORT studies were located; one randomised controlled trial, one study with a concurrent control group and five case series. Minor postoperative complications were reported following IORT. Short-term results were similar for both treatment modalities in terms of local recurrence, disease-free and overall survival. However, the current evidence base is poor, making definitive assessment on IORT very difficult. Further research is required to clarify several issues such as identification of the most appropriate subgroups of patients for IORT, a comparison of the currently available mobile IORT technologies, establishing whether IORT is most appropriate as a boost replacement dose or replacement for all postoperative radiotherapy, the examination of how biological repair processes may differ between the two treatment modalities and determining precisely where local recurrences originate with respect to the original tumour site.     

A phase I/II study of intraoperative radiotherapy in advanced unresectable or recurrent carcinoma of the rectum: A radiation therapy oncology group (RTOG) study

The Radiation Therapy Oncology Group (RTOG) initiated a phase I/II study of intraoperative radiotherapy (IORT) in advanced or recurrent rectal cancer to assess therapeutic efficacy, toxicity, and establish quality control guidelines prior to beginning a phase III trial. From October 1985 through December 1989, 87 patients with histologically proven adenocarcinoma of the rectum or rectosigmoid with recurrent/persistent disease after surgery or those primarily inoperable were entered by 14 institutions. Of 86 evaluable patients, 42 patients received IORT either alone (n = 15) or in combination with external beam (n = 27). Local control was dependent on the amount of residual disease prior to IORT, with 2-year actuarial local control of 77% if no gross residual disease remained vs. 10% with gross residual disease (P = 0.0001). For the recurrent/residual group (n = 33), this observation was also significant with a 2-year actuarial local control rate of 64% if no gross residual remained vs. 10% with gross residual disease (P = 0.004). Local control translated into an improved survival for all patients and the recurrent/residual group with 2-year actuarial survival of 88% and 89% if no gross residual disease remained vs. 48% and 45% with gross residual disease, respectively (P = .0005, 0.006). Six patients (14.6%) experienced four grade 3 and three grade 4 complications as a possible result of IORT during follow-up with a 2-year actuarial risk of major complications of 16%. We conclude that IORT is feasible within a cooperative group and can be performed with acceptable complication rates. A phase III trial to demonstrate a therapeutic advantage for IORT over external beam alone is currently in progress. © 1993 Wiley-Liss, Inc.     

Intra-operative radiotherapy (IORT) in pancreatic cancer: Joint analysis of the ISIORT-Europe experience

Purpose

A joint analysis of data from five contributing centers within the ISIORT-Europe program was performed to investigate the main contributions of intra-operative radiotherapy (IORT) to the multidisciplinary treatment of pancreatic cancer.

Materials and methods

Patients with a histologic diagnosis of carcinoma of the pancreas, with an absence of distant metastases, undergoing surgery with radical intent and IORT were considered eligible for participation in this study.

Results

From 1985 to 2006, a total of 270 patients were enrolled in the study from five European Institutions. Surgery was performed in 91.5% of cases and complicated by adverse events in 59 cases. External radiotherapy (ERT) preceded surgery in 23.9% of cases. One-hundred and six patients received further ERT. After surgery + IORT, median follow-up was 96 months (range 3-180). Median local control was 15 months, 5-year local control was 23.3%. Median overall survival was 19 months, while 5-year survival was 17.7%. A significantly greater local control and survival were observed in patients undergoing preoperative radiotherapy (LC: median not reached; OS: median 30 months) compared to patients treated with postoperative ERT alone (LC: median 28 months; OS: median 22 months), and to patients submitted to IORT exclusively (LC: median 8 months; OS: median 13 months) (p < 0.0001).

Conclusion

From this joint analysis emerges the fact that preoperative radiotherapy increases the effects of IORT in terms of local control and overall survival. The 5-year local control of 23.3% confirms the beneficial “sterilizing” effect of IORT on the tumor bed.     

Moderate dose intraoperative and external beam radiotherapy for locally recurrent rectal carcinoma.

BACKGROUND AND PURPOSE: Late adverse effects (i.e. neuropathy, chronic bowel obstruction) limit the effective dose given in intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT). Initial results of a multi-modality treatment approach using moderate dose IORT and moderate dose EBRT are presented. PATIENTS AND METHODS: Thirty-one consecutive patients with recurrent rectal carcinomas had IORT and EBRT after complete (R0, n = 14) or incomplete resection (R1, n = 9; R2, n = 8). The mean [ORT dose was 13.7 Gy (range 12-20 Gy) supplemented with an EBRT dose of 41.4 Gy. Twenty-two patients had preoperative EBRT and 22 patients had concomitant chemotherapy (5-FU, Leucovorine). RESULTS: After a median follow-up of 28 months, 16 patients had re-recurrent disease and 11 patients had died. Nine patients failed locally (four in-field, four marginal and one anastomotic re-recurrence), three combined with distant metastasis, resulting in overall and IORT infield local control rates of 71% and 87%, respectively. Distant metastases alone were found in seven patients. The 4-year overall and relapse-free survival rates were 58% and 48%, respectively. After incomplete resection the local failure rate increased (R0 21%, R1/2 35%) and the 4-year relapse-free survival rate decreased significantly (29% versus 71%) due to a markedly increased distant metastasis rate (53% versus 7%). Acute and late toxicities were not increased. CONCLUSION: The combination of moderate dose IORT and EBRT is a safe and efficacious component in a multi-modality treatment approach.     

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.     

Intraoperative electron beam radiation therapy for primary locally advanced rectal and rectosigmoid carcinoma

To improve local control and survival in patients with primary locally advanced rectal and rectosigmoid carcinoma, intraoperative electron beam radiation therapy (IORT) has been used with a combination of moderate- to high-dose preoperative radiation therapy and surgical resection. Sixty-five patients underwent resection with the intention of using IORT if areas at high risk for local recurrence were apparent at surgery. For 20 patients undergoing complete resection with IORT, the 5-year actuarial local control and disease-free survival (DFS) was 88% and 53%, respectively. The results for 22 patients with pathologically documented residual carcinoma were less satisfactory with a 5-year actuarial local control and DFS of 60% and 32%, respectively. In this latter group, local control and DFS correlated with the extent of residual disease: patients with only microscopic disease had a 5-year actuarial local control and DFS of 69% and 47%, respectively, whereas for patients with macroscopic disease, these figures were 50% and 17%, respectively. For 18 patients undergoing complete resection without IORT or additional postoperative radiation therapy, the 5-year actuarial local control and DFS was 67% and 53%, respectively. Because local failure will occur in at least 30% of patients undergoing partial resection with or without IORT as well as patients undergoing complete resection of advanced tumors without IORT, additional postoperative radiation therapy should be considered.     

Surgical management of retroperitoneal sarcomas associated with external and intraoperative electron beam radiotherapy.

AIMS: To report outcomes of adults with retroperitoneal sarcoma (RS) treated by surgery, external beam radiotherapy (EBRT) and intraoperative electron beam radiotherapy (IORT). METHODS: From July 1988 to February 2001; 24 patients with primary and recurrent RS were diagnosed and treated. The median dose and energy of IORT delivered was 15 Gy/9meV. EBRT dose varies between 45-50 Gy. RESULTS: There were five primary and 19 recurrent tumours. One primary and five recurrent tumours underwent R0 resection. There were 12 liposarcomas and 19 grade I tumours; 13 patients developed local recurrence and three developed distant metastases.Twenty-two patients received IORT associated with EBRT: 11 developed recurrences. Six patients developed Neurotoxicity (4 grade II and 2 grade III). Disease free survival and overall survival at 5 years was 28 and 56% respectively. CONCLUSIONS: EBRT with IORT treatment is a promising technique for local control. Lower recurrence rates are associated with radical (R0) surgical procedures.     

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).     

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.     

A phase I/II study of a hypoxic cell radiosensitizer KU-2285 in combination with intraoperative radiotherapy.

A fluorinated 2-nitroimidazole radiosensitizer KU-2285 was given before intraoperative radiotherapy (IORT) to 30 patients with unresectable, unresected or macroscopic residual tumours. Twenty-three patients had pancreatic cancer and five had osteosarcoma. The IORT dose was 30 Gy for unresectable pancreatic cancer and 60 Gy for osteosarcoma. The dose of KU-2285 administered ranged from 1 to 9 g m-2. Four patients received a dose of 9 g m-2, and ten received 6.8-7 g m-2. All patients tolerated KU-2285 well, and no drug-related toxicity was observed. The average tumour concentration of KU-2285 immediately after IORT was 166 microg g-1 at dose of 6.8-7 g m-2 and 333 microg g-1 at 9 g m-2. The average tumour-plasma ratio was > or = 0.82. Eleven patients with unresectable but localized pancreatic cancer treated with KU-2285 plus IORT and external beam radiotherapy had a median survival time of 11 months and 1-year local control rate of 50%, which compares favourably with those of 8 months (P = 0.26) and 28% (P = 0.10) for 22 matched historical control patients. The five patients with osteosarcoma attained local control. The results of this first study on KU-2285 and IORT appear encouraging, and further studies of this compound seem to be warranted.     

Intraoperative radiotherapy given as a boost for early breast cancer: long-term clinical and cosmetic results

PURPOSE: The standard radiotherapy (RT) of breast cancer consists of 50 Gy external beam RT (EBRT) to the whole breast followed by an electron boost of 10-16 Gy to the tumor bed, but this has several cosmetic disadvantages. Intraoperative radiotherapy (IORT) could be an alternative to overcome these. METHODS AND MATERIALS: We evaluated 50 women with early breast cancer operated on in a dedicated IORT facility. Median dose of 10 Gy was delivered using 9-MeV electron beams. All patients received postoperative EBRT (50 Gy in 2 Gy fractions). Late toxicity and cosmetic results were assessed independently by two physicians according to the Common Terminology Criteria for Adverse Event v3.0 grading system and the European Organization for Research and Treatment of Cancer questionnaires. RESULTS: After a median follow-up of 9.1 years (range, 5-15 years), two local recurrences were observed within the primary tumor bed. At the time of analysis, 45 patients are alive with (n = 1) or without disease. Among the 42 disease-free remaining patients, 6 experienced Grade 2 late subcutaneous fibrosis within the boost area. Overall, the scores indicated a very good quality of life and cosmesis was good to excellent in the evaluated patients. CONCLUSION: Our results confirm that IORT given as a boost after breast-conserving surgery is a reliable alternative to conventional postoperative fractionated boost radiation.