Intraoperative electron beam radiotherapy and perioperative high-dose-rate brachytherapy in previously irradiated oligorecurrent gynecological cancer: clinical outcome analysis

Background Pelvic recurrences from previously irradiated gynecological cancer lack solid evidence for recommendation on salvage. Methods A total of 58 patients were included in this clinical analysis. Salvage surgery was performed for locoregional relapse within previously irradiated pelvic area after initial surgery and adjuvant radiotherapy or radical external beam radiotherapy. The primary tumor diagnosis included cervical cancer (n = 47, 81%), uterine cancer (n = 4, 7%), and other types (n = 7, 12%). Thirty-three patients received adjuvant IOERT (1984–2000) at a median dose of 15 Gy (range 10–20 Gy) and 25 patients received adjuvant PHDRB (2001–2016) at a median dose of 32 Gy (range 24–40 Gy) in 6, 8, or 10 b.i.d. fractions. Results The median follow-up was 5.6 years (range 0.5–14.2 years). Twenty-nine (50.0%) patients had positive surgical margins. Grade ≥ 3 toxic events were recorded in 34 (58.6%) patients. The local control rate at 2 years was 51% and remained stable up to 14 years. Disease-free survival rates at 2, 5, and 10 years were 17.2, 15.5, and 15.5%, respectively. Overall survival rates at 2, 5, and 10 years were 58.1, 17.8, and 17.8%, respectively. Conclusions IOERT and PHDRB account for an effective salvage in oligorecurrent gynecological tumors. Patients with previous pelvic radiation suitable for salvage surgery and at risk of inadequate margins could benefit from adjuvant reirradiation in form of IOERT or PHDRB. However, the rate of severe grade ≥ 3 toxicity associated with the entire treatment program is relevant and needs to be closely counterbalanced against the expected therapeutic gain (AU)

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy.

BACKGROUND: The purpose of this study was to investigate the prevalence of ypN+ status according to ypT category in patients with locally advanced rectal cancer treated with chemoradiotherapy and total mesorectal excision, and to assess the impact of ypN+ on disease recurrence and survival by pooled analysis of individual-patient data. METHODS: Individual-patient data from 10 studies of chemoradiotherapy for rectal cancer were included. Pooled rates of ypN+ disease were calculated with 95 per cent confidence interval for each ypT category. Kaplan-Meier and Cox regression analyses were undertaken to assess influence of ypN status on 5-year disease-free survival (DFS) and overall survival (OS). RESULTS: Data on 1898 patients were included in the study. Median follow-up was 50 (range 0-219) months. The pooled rate of ypN+ disease was 7 per cent for ypT0, 12 per cent for ypT1, 17 per cent for ypT2, 40 per cent for ypT3, and 46 per cent for ypT4 tumours. Patients with ypN+ disease had lower 5-year DFS and OS (46.2 and 63.4 per cent respectively) than patients with ypN0 tumours (74.5 and 83.2 per cent) (P < 0.001). Cox regression analyses showed ypN+ status to be an independent predictor of recurrence and death. CONCLUSION: Risk of nodal metastases (ypN+) after chemoradiotherapy increases with advancing ypT category and needs to be considered if an organ-preserving strategy is contemplated.

When patients are diagnosed with rectal cancer and the tumour grows beyond the rectal wall there is a high risk that the tumour has spread to nearby lymph nodes. This study showed that this relationship between tumour invasion depth and lymph node involvement is similar after treatment with (chemo)radiotherapy. Patients who have tumour cells remaining in the lymph nodes after (chemo) radiotherapy have a worse prognosis than patients who do not have cancer cells remaining in the lymph nodes. When an organ-preserving treatment is considered as an alternative therapy, this should be kept in mind during patient counselling.

Intraoperative electron beam radiotherapy and perioperative high-dose-rate brachytherapy in previously irradiated oligorecurrent gynecological cancer: clinical outcome analysis.

BACKGROUND: Pelvic recurrences from previously irradiated gynecological cancer lack solid evidence for recommendation on salvage. METHODS: A total of 58 patients were included in this clinical analysis. Salvage surgery was performed for locoregional relapse within previously irradiated pelvic area after initial surgery and adjuvant radiotherapy or radical external beam radiotherapy. The primary tumor diagnosis included cervical cancer (n = 47, 81%), uterine cancer (n = 4, 7%), and other types (n = 7, 12%). Thirty-three patients received adjuvant IOERT (1984-2000) at a median dose of 15 Gy (range 10-20 Gy) and 25 patients received adjuvant PHDRB (2001-2016) at a median dose of 32 Gy (range 24-40 Gy) in 6, 8, or 10 b.i.d. fractions. RESULTS: The median follow-up was 5.6 years (range 0.5-14.2 years). Twenty-nine (50.0%) patients had positive surgical margins. Grade ≥ 3 toxic events were recorded in 34 (58.6%) patients. The local control rate at 2 years was 51% and remained stable up to 14 years. Disease-free survival rates at 2, 5, and 10 years were 17.2, 15.5, and 15.5%, respectively. Overall survival rates at 2, 5, and 10 years were 58.1, 17.8, and 17.8%, respectively. CONCLUSIONS: IOERT and PHDRB account for an effective salvage in oligorecurrent gynecological tumors. Patients with previous pelvic radiation suitable for salvage surgery and at risk of inadequate margins could benefit from adjuvant reirradiation in form of IOERT or PHDRB. However, the rate of severe grade ≥ 3 toxicity associated with the entire treatment program is relevant and needs to be closely counterbalanced against the expected therapeutic gain.

Intraoperative electron-beam radiation therapy with or without external-beam radiotherapy in the management of paraaortic lymph-node oligometastases from gynecological malignancies.

PURPOSE: To analyze long-term outcomes and prognostic factors in patients with paraaortic lymph-node oligometastases (LNO) from gynecological malignancies treated in a multimodal protocol. METHODS: Patients with a histological diagnosis of LNO gynecological cancer [uterine cervix (n = 14, 40 %), endometrial (n = 18, 51 %), ovarian (n = 3, 9 %)] who underwent surgery with radical intent and intraoperative radiotherapy (IORT), median dose 12.5 Gy) were considered eligible for participation in this study. Additionally, 51 % received external-beam radiotherapy (EBRT). RESULTS: From 1997 to 2012, a total of 35 patients from a single institution were analyzed. With a median follow-up time of 55 months (range 2-148), 5-year loco-regional control (LRC), disease-free survival (DFS) and overall survival (OS) were 79, 44 and 49 %, respectively. On multivariate analysis, no EBRT treatment to the LNO (p = 0.03), and time interval from primary tumor diagnosis to LNO <24 months (p = 0.04) remained significantly associated with locoregional recurrence (LRR). We found on multivariate analysis that only R1 margin status (p = 0.01) was significantly associated with OS. CONCLUSION: From the current series of patients with gynecological LNO, it emerges the fact that EBRT promotes local control. Future prospective studies might be designed according to the predicted risk of LRR focusing on different subgroups.

Infrastructures, treatment modalities, and workload of radiation oncology departments in Spain with special attention to prostate cancer.

AIM: The purpose of the study was to describe infrastructures, treatment modalities, and workload in radiation oncology (RO) in Spain, referred particularly to prostate cancer (PC). METHODS: An epidemiologic, cross-sectional study was performed during 2008-2009. A study-specific questionnaire was sent to the 108 RO-registered departments. RESULTS: One hundred and two departments answered the survey, and six were contacted by telephone. Centers operated 236 treatment units: 23 (9.7 %) cobalt machines, 37 (15.7 %) mono-energetic linear accelerators, and 176 (74.6 %) multi-energy linear accelerators. Sixty-one (56.4 %) and 33 (30.5 %) departments, respectively, reported intensity-modulated radiation therapy (IMRT) and image-guided RT (IGRT) capabilities; three-dimensional-conformal RT was used in 75.8 % of patients. Virtual simulators were present in 95 departments (88.0 %), 35 use conventional simulators. Fifty-one departments (47.2 %) have brachytherapy units, 38 (35.2 %) perform prostatic implants. Departments saw a mean of 24.9 new patients/week; the number of patients treated annually was 102,054, corresponding to 88.4 % of patients with a RT indication. In 56.5 % of the hospitals, multidisciplinary teams were available to treat PC. CONCLUSIONS: Results provide an accurate picture of current situation of RO in Spain, showing a trend toward the progressive introduction of new technologies (IMRT, IGRT, brachytherapy).

The use of radiotherapy for early breast cancer in woman at different ages.

Age is an important feature at the time of early breast cancer diagnosis. Radiotherapy is a mandatory component of treatment for breast-conserving strategies in early disease stages. Breast radiotherapy has rapidly evolved in the last 20 years. A tendency to less treatment volume (partial-breast irradiation) and less treatment time (hypofractionation) is consolidated in modern radiation oncology practice. Age and risk for local recurrence guide the decision-making process to electro-optimal treatment. Radiotherapy technological versatility offers multiple options for individualized (risk-age adapted) recommendations.

Intraoperative radiotherapy-containing multidisciplinary management of trunk-wall soft-tissue sarcomas.

PURPOSE: A joint analysis of data from centers within the intraoperative radiotherapy (IORT)-Spanish cooperative initiative was performed to investigate the main contributions of IORT to the multidisciplinary treatment of trunk-wall soft-tissue sarcoma (TW-STS). MATERIALS AND METHODS: Patients with a histologic diagnosis of TW-STS (primary tumor 53 %; locally recurrent 47 %) with absence of distant metastases, undergoing surgery with radical intent and IORT (median dose 12.5 Gy) were considered eligible for participation in this study. In addition, all primary tumors received external-beam radiotherapy (median dose 50 Gy). RESULTS: From 1986 to 2012, a total of 68 patients were analyzed in the study from three Spanish institutions. With a median follow-up time of 53 months (range 4-316), 5-year local control (LC) was 58 %. Five-year IORT in-field control, disease-free survival (DFS) and overall survival were 70, 45 and 51 %, respectively. On multivariate analysis, only microscopically involved margin (R1) resection status retained significance in relation to LC (HR 3.97, p < 0.001). In regard to IORT in field control, incomplete resection (HR 3.23, p = 0.008) and recurrent disease status (HR 2.52, p = 0.04) retained a significant association in multivariate analysis. CONCLUSION: From this joint analysis emerges the fact that margin and disease status influences local and central control, but DFS remains modest, given the high risk of distant metastases. Intensified local treatment needs to be tested in the context of more efficient concurrent, neo-, and adjuvant systemic therapy.

Post-chemoradiation anastomotic recurrence in locally advanced rectal cancer: no increased risk associated with distal margin.

BACKGROUND AND PURPOSE: Anastomotic recurrence after radical sphincter-preserving surgery preceded by neoadjuvant therapy in locally advanced rectal cancer is an uncommon event that merits further assessment. The aim of this study is to analyze the effect of preoperative chemoradiation on the risk of anastomotic recurrence. Based on the initial extension of the tumor, we analyzed whether the distal surgical section was calculated through the virtual initial extension of the rectal tumor. PATIENTS AND METHODS: Eligible patients with locally advanced rectal cancer were offered preoperative chemoradiation, sphincter sparing surgery and intraoperative radiation therapy boost. RESULTS: 180 patients were treated with anterior resection (40 %), low anterior resection (45.6 %) and ultra-low anterior resection (14.4 %). With a median follow-up of 41.1 months (0.36-143 months), anastomotic recurrence was diagnosed in 9 patients (5 %). There was no statistical correlation with downstaging (T or N), downsizing effects, or with distance from the lower limit of the residual lesion to the distal margin. Virtual intratumoral surgical section was speculated in 44 patients (3 developed anastomotic recurrence; 6.8 vs 4.8 %, p = 0.482). CONCLUSION: Anastomotic recurrence in patients with rectal cancer treated with neoadjuvant chemoradiation is an infrequent event. Virtual intratumoral surgical sections followed by anastomosis do not contribute to an excessive risk of recurrence. Our findings encourage the development of policies for preservation of the ano-rectal complex in rectal cancer patients.

Preoperative chemoradiation with or without induction oxaliplatin plus 5-fluorouracil in locally advanced rectal cancer. Long-term outcome analysis.

BACKGROUND AND PURPOSE: It has been previously reported that a short FOLFOX-4 induction significantly improves pathologic complete response in locally advanced rectal cancer (LARC) patients treated with preoperative chemoradiation (CRT). In a larger and updated patient series, we analyzed FOLFOX-4 efficacy in terms of sphincter preservation and long-term outcomes. PATIENTS AND METHODS: From January 1995 to December 2010, 335 LARC patients were treated with preoperative chemoradiation (4500-5040 cGy). Starting in May 2001, 207 consecutive patients additionally received induction FOLFOX-4. Surgery was performed 6 weeks (range 3-12 weeks) after chemoradiation. RESULTS: Incidence of total tumor (63 vs. 54 %, p = 0.02) and nodal downstaging (60 vs. 43 %, p = 0.002) was significantly increased by induction FOLFOX-4. In an analysis of tumors located below 5 cm from the anal verge (n = 114, 34 %), sphincter preservation was feasible in 30 % in the FOLFOX-4 versus 13 % in the upfront CRT group (p = 0.04). Median follow-up time for the entire cohort of patients was 72.6 months (range 4-205 months). FOLFOX-4 was not associated with superior locoregional control (HR 0.88, p = 0.78), disease-free survival (HR 0.83, p = 0.55), distant metastases-free survival (HR 0.94, p = 0.81), or cancer-specific survival (HR 0.70, p = 0.15). CONCLUSION: Short-intense induction FOLFOX-4 significantly improves downstaging and sphincter preservation in low rectal tumors. Long-term outcomes were not improved in the FOLFOX-4 group of patients.

External-beam radiation therapy after surgical resection and intraoperative electron-beam radiation therapy for oligorecurrent gynecological cancer. Long-term outcome.

PURPOSE: The goal of the present study was to analyze prognostic factors in patients treated with external-beam radiation therapy (EBRT), surgical resection and intraoperative electron-beam radiotherapy (IOERT) for oligorecurrent gynecological cancer (ORGC). PATIENTS AND METHODS: From January 1995 to December 2012, 61 patients with ORGC [uterine cervix (52 %), endometrial (30 %), ovarian (15 %), vagina (3 %)] underwent IOERT (12.5 Gy, range 10-15 Gy), and surgical resection to the pelvic (57 %) and paraaortic (43 %) recurrence tumor bed. In addition, 29 patients (48 %) also received EBRT (range 30.6-50.4 Gy). Survival outcomes were estimated using the Kaplan-Meier method, and risk factors were identified by univariate and multivariate analyses. RESULTS: Median follow-up time for the entire cohort of patients was 42 months (range 2-169 months). The 10-year rates for overall survival (OS) and locoregional control (LRC) were 17 and 65 %, respectively. On multivariate analysis, no tumor fragmentation (HR 0.22; p = 0.03), time interval from primary tumor diagnosis to locoregional recurrence (LRR) < 24 months (HR 4.02; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.95; p = 0.02) retained significance with regard to LRR. Time interval from primary tumor to LRR < 24 months (HR 2.32; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.77; p = 0.04) showed a significant association with OS after adjustment for other covariates. CONCLUSION: External-beam radiation therapy at the time of pelvic recurrence, time interval for relapse ≥ 24 months and not multi-involved fragmented resection specimens are associated with improved LRC in patients with ORGC. As suggested from the present analysis a significant group of ORGC patients could potentially benefit from multimodality rescue treatment.

Feasibility of integrating a multi-camera optical tracking system in intra-operative electron radiation therapy scenarios.

Intra-operative electron radiation therapy (IOERT) combines surgery and ionizing radiation applied directly to an exposed unresected tumour mass or to a post-resection tumour bed. The radiation is collimated and conducted by a specific applicator docked to the linear accelerator. The dose distribution in tissues to be irradiated and in organs at risk can be planned through a pre-operative computed tomography (CT) study. However, surgical retraction of structures and resection of a tumour affecting normal tissues significantly modify the patient's geometry. Therefore, the treatment parameters (applicator dimension, pose (position and orientation), bevel angle, and beam energy) may require the original IOERT treatment plan to be modified depending on the actual surgical scenario. We propose the use of a multi-camera optical tracking system to reliably record the actual pose of the IOERT applicator in relation to the patient's anatomy in an environment prone to occlusion problems. This information can be integrated in the radio-surgical treatment planning system in order to generate a real-time accurate description of the IOERT scenario. We assessed the accuracy of the applicator pose by performing a phantom-based study that resembled three real clinical IOERT scenarios. The error obtained (2 mm) was below the acceptance threshold for external radiotherapy practice, thus encouraging future implementation of this approach in real clinical IOERT scenarios.

Research opportunities in intraoperative radiation therapy: the next decade 2013-2023

The reality of intraoperative radiation therapy (IORT) practice is consistent with an efficient and highly precise radiation therapy technique to safely boost areas at risk for local recurrence. Long-term clinical experience has shown that IORT-containing multi-modality regimens appear to improve local disease control, if not survival in many diseases. Research with IORT is a multidisciplinary scenario that covers knowledge from radiation beam adapted development to advance molecular biology for bio-predictability of outcome. The technical parameters employed in IORT procedures are important information to be recorded for quality assurance and clinical results analysis. In addition, specific treatment planning systems for IORT procedures are available, to help in the treatment decision-making process. A systematic revision of opportunities for research and innovation in IORT is reported including radiation beam modulation, delivery, dosimetry and planning; infrastructure and treatment factors; experimental and clinical radiobiology; clinical trials, innovation and translational research development (AU)

Clinical and technical characteristics of intraoperative radiotherapy. Analysis of the ISIORT-Europe database.

BACKGROUND: A joint analysis of clinical data from centres within the European section of the International Society of Intraoperative Radiation Therapy (ISIORT-Europe) was undertaken in order to define the range of intraoperative radiotherapy (IORT) techniques and indications encompassed by its member institutions. MATERIALS AND METHODS: In 2007, the ISIORT-Europe centres were invited to record demographic, clinical and technical data relating to their IORT procedures in a joint online database. Retrospective data entry was possible. RESULTS: The survey encompassed 21 centres and data from 3754 IORT procedures performed between 1992 and 2011. The average annual number of patients treated per institution was 42, with three centres treating more than 100 patients per year. The most frequent tumour was breast cancer with 2395 cases (63.8 %), followed by rectal cancer (598 cases, 15.9 %), sarcoma (221 cases, 5.9 %), prostate cancer (108 cases, 2.9 %) and pancreatic cancer (80 cases, 2.1 %). Clinical details and IORT technical data from these five tumour types are reported. CONCLUSION: This is the first report on a large cohort of patients treated with IORT in Europe. It gives a picture of patient selection methods and treatment modalities, with emphasis on the main tumour types that are typically treated by this technique and may benefit from it.

Intraoperative radiotherapy for the treatment of resectable locally advanced gastric adenocarcinoma: topography of locoregional recurrences and long-term outcomes

INTRODUCTION: To report feasibility, tolerance, anatomical sites of upper abdominal locoregional recurrence and long-term outcome of gastric cancer patients treated with surgery and a component of intraoperative electron beam radiotherapy (IORT). MATERIALS AND METHODS: From January 1995 to December 2010, 32 patients with primary gastric adenocarcinoma treated with curative resection (R0) [total gastrectomy (n = 9; 28 %), subtotal (n = 23; 72 %) and D2 lymphadenectomy in all patients] and apparent disease confined to locoregional area [Stage: II (n = 15; 47 %), III (n = 17; 53 %)] were treated with a component of IORT (IORT applicator size 5-9 cm in diameter, dose 10-15 Gy, beam energy 6-5 MeV) over the celiac axis and peripancreatic nodal areas. Sixteen (50 %) patients also received adjuvant treatment (external beam radiotherapy n = 6, chemoradiation n = 9, chemotherapy alone n = 1). RESULTS: With a median follow-up time of 40 months (range, 2-60), locoregional recurrence was observed in five (16 %) patients (4 nodal in hepatic hilum and 1 anastomotic). Only pN1 patients developed locoregional relapse. No recurrence was observed in the IORT-treated target volume (celiac trunk and peripancreatic nodes). Overall survival at 5 years was 54.6 % (95 % CI: 48.57-60.58). Postoperative mortality was 6 % (n = 2) and postoperative complications 19 % (n = 6). CONCLUSIONS: It is feasible to integrate IORT as a component of radiotherapy in combined modality therapy of gastric cancer. Local control is high in the radiation boosted area, but marginal regional extension (in particular, involving the hepatic hilum) might be considered as part of the anatomic IORT target volume at risk in pN+ patients (AU)

Intraoperative electron beam radiotherapy and extended surgical resection for gynecological pelvic recurrent malignancies with and without external beam radiation therapy: long-term outcomes.

OBJECTIVE: To analyze prognostic factors in patients treated with intraoperative electrons containing resective surgical rescue of locally recurrent gynecological cancer (LRGC). METHODS: From January 1995 to December 2012, 35 patients with LRGC [uterine cervix (57%), endometrial (20%), ovarian (17%), vagina (6%)] underwent extended [multiorgan (54%), bone (9%), soft tissue (54%), vascular (14%)] surgery and intraoperative electron-beam radiation therapy [IOERT (10-15 Gy)] to the pelvic recurrence tumor bed. Sixteen (46%) patients also received external beam radiation therapy [EBRT (30.6-50.4 Gy)]. Survival outcomes were estimated using the Kaplan-Meier method, and risk factors were identified by univariate and multivariate analyses. RESULTS: Median follow-up time for the entire cohort of patients was 46 months (range, 3-169). Ten-year rates for locoregional control (LRC) and overall survival (OS) were 58 and 16%, respectively. On multivariate analysis non-EBRT at the time of pelvic re-recurrence [HR 4.15; p = 0.02], no tumor fragmentation [HR 0.13; p=0.05] and time interval from primary tumor to LRR < 24 months [HR 5.16; p=0.01], retained significance with regard to LRR. Non-EBRT at the time of pelvic re-recurrence [HR 4.18; p=0.02] and time interval from primary tumor to LRR < 24 months [HR 6.67; p=0.02] showed a significant association with OS after adjustment for other covariates. CONCLUSIONS: EBRT treatment integrated for rescue, time interval for relapse ≥ 24 months, and not multi-involved fragmented resection specimens are associated with improved LRC in patients with LRGC in the pelvis. Present results suggest that a significant group of patients may benefit from EBRT treatment integrated with extended surgery and IOERT.

Research opportunities in intraoperative radiation therapy: the next decade 2013-2023.

The reality of intraoperative radiation therapy (IORT) practice is consistent with an efficient and highly precise radiation therapy technique to safely boost areas at risk for local recurrence. Long-term clinical experience has shown that IORT-containing multi-modality regimens appear to improve local disease control, if not survival in many diseases. Research with IORT is a multidisciplinary scenario that covers knowledge from radiation beam adapted development to advance molecular biology for bio-predictability of outcome. The technical parameters employed in IORT procedures are important information to be recorded for quality assurance and clinical results analysis. In addition, specific treatment planning systems for IORT procedures are available, to help in the treatment decision-making process. A systematic revision of opportunities for research and innovation in IORT is reported including radiation beam modulation, delivery, dosimetry and planning; infrastructure and treatment factors; experimental and clinical radiobiology; clinical trials, innovation and translational research development.

Intraoperative radiotherapy for the treatment of resectable locally advanced gastric adenocarcinoma: topography of locoregional recurrences and long-term outcomes.

INTRODUCTION: To report feasibility, tolerance, anatomical sites of upper abdominal locoregional recurrence and long-term outcome of gastric cancer patients treated with surgery and a component of intraoperative electron beam radiotherapy (IORT). MATERIALS AND METHODS: From January 1995 to December 2010, 32 patients with primary gastric adenocarcinoma treated with curative resection (R0) [total gastrectomy (n = 9; 28 %), subtotal (n = 23; 72 %) and D2 lymphadenectomy in all patients] and apparent disease confined to locoregional area [Stage: II (n = 15; 47 %), III (n = 17; 53 %)] were treated with a component of IORT (IORT applicator size 5-9 cm in diameter, dose 10-15 Gy, beam energy 6-5 MeV) over the celiac axis and peripancreatic nodal areas. Sixteen (50 %) patients also received adjuvant treatment (external beam radiotherapy n = 6, chemoradiation n = 9, chemotherapy alone n = 1). RESULTS: With a median follow-up time of 40 months (range, 2-60), locoregional recurrence was observed in five (16 %) patients (4 nodal in hepatic hilum and 1 anastomotic). Only pN1 patients developed locoregional relapse. No recurrence was observed in the IORT-treated target volume (celiac trunk and peripancreatic nodes). Overall survival at 5 years was 54.6 % (95 % CI: 48.57-60.58). Postoperative mortality was 6 % (n = 2) and postoperative complications 19 % (n = 6). CONCLUSIONS: It is feasible to integrate IORT as a component of radiotherapy in combined modality therapy of gastric cancer. Local control is high in the radiation boosted area, but marginal regional extension (in particular, involving the hepatic hilum) might be considered as part of the anatomic IORT target volume at risk in pN+ patients.