Intraoperative radiotherapy combined with spinal stabilization surgery-a novel treatment strategy for spinal metastases based on a first single-center experiences

INTRODUCTION

Current treatment of spinal metastases (SM) aims on preserving spinal stability, neurological status, and functional status as well as achieving local control. It consists of spinal surgery followed by radiotherapy and/or systemic treatment. Adjuvant therapy usually starts with a delay of a few weeks to prevent wound healing issues. Intraoperative radiotherapy (IORT) has previously been successfully applied during brain tumor, breast and colorectal carcinoma surgery but not in SM, including unstable one, to date. In our case series, we describe the feasibility, morbidity and mortality of a novel treatment protocol for SM combining stabilization surgery with IORT.

METHODS

Single center case series on patients with SM. Single session stabilization by navigated open or percutaneous procedure using a carbon screw-rod system followed by concurrent 50 kV photon-IORT (ZEISS Intrabeam). The IORT probe is placed via a guide canula using navigation, positioning is controlled by IOCT or 3D-fluroscopy enabling RT isodose planning in the OR.

RESULTS

15 (8 female) patients (71 ± 10y) received this treatment between 07/22 and 09/23. Median Spinal Neoplastic Instability Score was 8 [7-10] IQR. Most metastasis were located in the thoracic (n = 11, 73.3%) and the rest in the lumbar (n = 4, 26.7%) spine. 9 (60%) patients received open, 5 (33%) percutaneous stabilization and 1 (7%) decompression only. Mean length of surgery was 157 ± 45 min. Eleven patients had 8 and 3 had 4 screws placed. In 2 patients radiotherapy was not completed due to bending of the guide canula with consecutive abortion of IORT. All other patients received 8 Gy isodoses at mdn. 1.5 cm [1.1-1.9, IQR] depth during 2-6 min. The patients had Epidural Spinal Cord Compression score 1a-3. Seven patients (46.7%) experienced adverse events including 2 surgical site infection (one 65 days after surgery).

CONCLUSION

50 kV photon IORT for SM and consecutive unstable spine needing surgical intervention is safe and feasible and can be a promising technique in selected cases.

Impaired Aortic Growth in Neuroblastoma Patients After Intensive Treatment

PURPOSE

This study evaluated the abdominal aortic diameter in high-risk neuroblastoma (NB) patients and the risk of aortic narrowing following intensive treatment.

METHODS

We measured the aortic diameter at four specific levels of the abdominal aorta (diaphragmatic crus, celiac axis, and the root of the superior (SMA) and inferior (IMA) mesenteric arteries) on contrast CT scans. The control group consisted of 56 children with non-oncologic disorders, while the NB group included 35 patients with high-risk abdominal NB. We used regression analysis of age and aortic diameter to determine the regression formula for each level in each group and performed intergroup comparisons using t-test.

RESULTS

We evaluated a total of 160 contrast-enhanced CTs performed in the 35 eligible cases. The aortic diameter of pretreated NB patients was not significantly different from the controls. After receiving any treatment, the aortic diameter was significantly smaller in the NB group (p < 0.01 each). Patients who underwent radical surgery, particularly gross total resection (n = 26), had smaller aortic diameters at all levels compared to controls (p < 0.01 each). Patients treated with radiotherapy (RT) had smaller aortic diameters than controls. External beam radiotherapy (EBRT) patients (n = 24) had smaller aortic diameters at all levels except the celiac axis (crus, SMA, IMA; p < 0.01 each), and intraoperative radiotherapy (IORT) ± EBRT patients (n = 5) had smaller aortic diameters at all levels (p < 0.01 each).

CONCLUSION

Patients with NB may experience impaired development of the abdominal aorta after multimodal therapy, particularly after RT. Close observation and long-term follow-up is essential to monitor for catastrophic vascular complications.

LEVEL OF EVIDENCE

LEVEL III.

Efficacy and Safety of Intraoperative Radiotherapy for High-Grade Gliomas: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

High-grade gliomas (HGGs) are aggressive tumors of the central nervous system that cause significant morbidity and mortality. Despite advances in surgery and radiation therapy (RT), HGG still has a high incidence of recurrence and treatment failure. Intraoperative radiotherapy (IORT) has emerged as a promising therapeutic approach to achieve local tumor control while sparing normal brain tissue from radiation-induced damage.

METHODS

A systematic review and meta-analysis were conducted following PRISMA guidelines to evaluate the use of IORT for HGG. Eligible studies were included based on specific criteria, and data were independently extracted. Outcomes of interest included complications, IORT failure, survival rates at 12 and 24 months, and mortality.

RESULTS

Sixteen studies comprising 436 patients were included. The overall complication rate after IORT was 17%, with significant heterogeneity observed. The IORT failure rate was 77%, while the survival rates at 12 and 24 months were 74% and 24%, respectively. The mortality rate was 62%.

CONCLUSION

This meta-analysis suggests that IORT may be a promising adjuvant treatment for selected patients with HGG. Despite the high rate of complications and treatment failures, the survival outcomes were comparable or even superior to conventional methods. However, the limitations of the study, such as the lack of a control group and small sample sizes, warrant further investigation through prospective randomized controlled trials to better understand the specific patient populations that may benefit most from IORT. However, the limitations of the study, such as the lack of a control group and small sample sizes, warrant further investigation. Notably, the ongoing RP3 trial (NCT02685605) is currently underway, with the aim of providing a more comprehensive understanding of IORT. Moreover, future research should focus on managing complications associated with IORT to improve its safety and efficacy in treating HGG.

Intraoperative radiotherapy in recurrent IDH-wildtype glioblastoma with gross total resection: A single-center retrospective study

BACKGROUND

Isocitrate dehydrogenase-wildtype (IDHwt) glioblastoma (GBM) is one of the most aggressive primary brain tumors. The recurrence of GBM is almost inevitable. As an adjuvant option to surgery, intraoperative radiotherapy (IORT) is gaining increasing attention in the treatment of glioma. This study is aimed to evaluate the therapeutic efficacy of IORT on recurrent IDHwt GBM.

METHODS

In total, 34 recurrent IDHwt GBM patients who received a second surgery were included in the analysis (17 in the surgery group and 17 in the surgery + IORT group).

RESULTS

The progression-free survival and overall survival after the second surgery were defined as PFS2 and OS2, respectively. The median PFS2 was 7.3 months (95% CI: 6.3-10.5) and 10.6 months (95% CI: 9.3-14.6) for those patients who received surgery and surgery + IORT, respectively. Patients in the surgery + IORT group also had a longer OS2 (12.8 months, 95% CI: 11.4-17.2) than those in the surgery group (9.3 months, 95% CI: 8.9-12.9). The Kaplan-Meier survival curves, analyzed by log-rank test, revealed a statistically significant difference in PFS2 and OS2 between both groups, suggesting that IORT plays an active role in the observed benefits for PFS2 and OS2. The effects of IORT on PFS2 and OS2 were further confirmed by multivariate Cox hazards regression analysis. Two patients in the surgery group developed distant glioma metastases, and no radiation-related complications were observed in the IORT group.

CONCLUSIONS

This study suggests that low-dose IORT may improve the prognosis of recurrent IDHwt GBM patients. Future prospective large-scale studies are needed to validate the efficacy and safety of IORT.

Analysis of postoperative morbidity and mortality in a single center cohort

INTRODUCTION

In order to improve surgical outcome and accelerate the adjuvant oncologic therapy, intraoperative Radiotherapy (IORT) has become a treatment option in oncologic surgery for various diseases including glioma and brain metastasis (BM). BMs are often located in the cranial posterior fossa (PF) requiring specific surgical considerations due to its complex anatomy. Up until now, data on IORT for BMs is limited and detailed description in the use of IORT for lesions in the PF is lacking. Our aim is to provide more insight into this emerging treatment strategy.

METHODS

We performed a retrospective analysis of patients receiving surgery for BMs and undergoing IORT at our institution. Each patient was discussed at the interdisciplinary tumor board decision before the intervention. Patient characteristics, functional status (Karnofsky Performance Score, KPS) before and after surgery, disease (recursive partitioning analysis, lesion size) and operative parameters were analyzed. Adverse events (AE) were recorded up until 30 days after the intervention and rated according to the Clavien Dindo Rating scale.

RESULTS

Nine patients (5 female) were included. None underwent prior radiotherapy (RT). Mean age was 66 ± 11 years. Preoperative median KPS was 80%. Mean BM diameter was 3.2 ± 0.9 cm. There was no statistically significant deterioration of the functional status after the intervention. Two patients experienced AEs with both of them needing revision surgery.

CONCLUSION

Surgery for BMs with IORT in the PF seems safe and feasible. Further studies are needed to evaluate the influence of IORT on long-term outcome after BM surgery.

Intraoperative or postoperative stereotactic radiotherapy for brain metastases: time to systemic treatment onset and other patient-relevant outcomes

PURPOSE

Intraoperative radiotherapy (IORT) has become a viable treatment option for resectable brain metastases (BMs). As data on local control and radiation necrosis rates are maturing, we focus on meaningful secondary endpoints such as time to next treatment (TTNT), duration of postoperative corticosteroid treatment, and in-hospital time.

METHODS

Patients prospectively recruited within an IORT study registry between November 2020 and June 2023 were compared with consecutive patients receiving adjuvant stereotactic radiotherapy (SRT) of the resection cavity within the same time frame. TTNT was defined as the number of days between BM resection and start of the next extracranial oncological therapy (systemic treatment, surgery, or radiotherapy) for each of the groups.

RESULTS

Of 95 BM patients screened, IORT was feasible in 84 cases (88%) and ultimately performed in 64 (67%). The control collective consisted of 53 SRT patients. There were no relevant differences in clinical baseline features. Mean TTNT (range) was 36 (9 - 94) days for IORT patients versus 52 (11 - 126) days for SRT patients (p = 0.01). Mean duration of postoperative corticosteroid treatment was similar (8 days; p = 0.83), as was mean postoperative in-hospital time (11 versus 12 days; p = 0.97). Mean total in-hospital time for BM treatment (in- and out-patient days) was 11 days for IORT versus 19 days for SRT patients (p < 0.001).

CONCLUSION

IORT for BMs results in faster completion of interdisciplinary treatment when compared to adjuvant SRT, without increasing corticosteroid intake or prolonging in-hospital times. A randomised phase III trial will determine the clinical effects of shorter TTNT.

Outcomes of Breast Intraoperative Electron Beam Radiotherapy (IOeRT) : Case Series of Single Institute Experience in Saudi Arabia

INTRODUCTION

85-90% of local recurrences after breastconserving surgery occurs within the index quadrant. Intraoperative radiotherapy may be a good alternative for eligible patients avoiding long course of adjuvant radiation.

PATIENTS AND METHODS

Eligible patients were early stage node negative at least 50 years at time of inclusion, unicentric less than 30mm in diameter any hormone receptor status. 21 Gy was delivered intraoperatively, biologically equivalent to 58 to 60 Gy in standard fractionation using electron beam to 90% isodose line. Cosmetic, Oncological and Patient Satisfaction Evaluation of treated Patients between March 2018 and August 2020 at the King Khalid university hospital, using the IOeRT (Mobetron® ). Evaluation done at a combined clinic between surgical and radiation oncology teams at the end of the follow up period before publication.

RESULTS

15 female patients were evaluable with mean follow up period 33.8 months (19-48 months). Mean Age 56.4 years (50-65 years). Mean tumor size 1.213 cm. Majority of patients were T1. 2 patients showed Sentinel lymph node positive.21 Gy was delivered intraoperatively.4 Patients (26.7%) received adjuvant postoperative external beam radiation therapy (EBRT). 2 patients due to being in Caution group due to positive extensive Ductal carcinoma in situ (DCIS). External beam radiation was 40 Gy/15 fractions/3 weeks using three dimensional radiation therapy (3DCRT). Cosmetically, Apart from one patient score 9 due to presence of keloid scar formation, most patients were in range of 0-3 according to physician evaluation and Modified Hollander's score otherwise, No more than score 3 in any of the patients was detected. Oncologically, Till the time of publication no local or distant relapses was detected. As a patient experience, 100 % of patients were satisfied.

CONCLUSION

Breast IOERT is a convenient, safe and a valid treatment modality as an option for patients who are otherwise appropriate candidates for APBI. Proper patient selection should focus on clinicopathologic factors predictive of negative nodes and negative margins. Careful assessment of preoperative mammographic and other imaging studies for features, such as extent of calcifications, may be helpful.

Outcome assessment of intraoperative radiotherapy for brain metastases: results of a prospective observational study with comparative matched-pair analysis

PURPOSE

Intraoperative radiation therapy (IORT) is an emerging alternative to adjuvant stereotactic external beam radiation therapy (EBRT) following resection of brain metastases (BM). Advantages of IORT include an instant prevention of tumor regrowth, optimized dose-sparing of adjacent healthy brain tissue and immediate completion of BM treatment, allowing an earlier admission to subsequent systemic treatments. However, prospective outcome data are limited. We sought to assess long-term outcome of IORT in comparison to EBRT.

METHODS

A total of 35 consecutive patients, prospectively recruited within a study registry, who received IORT following BM resection at a single neuro-oncological center were evaluated for radiation necrosis (RN) incidence rates, local control rates (LCR), distant brain progression (DBP) and overall survival (OS) as long-term outcome parameters. The 1 year-estimated OS and survival rates were compared in a balanced comparative matched-pair analysis to those of our institutional database, encompassing 388 consecutive patients who underwent adjuvant EBRT after BM resection.

RESULTS

The median IORT dose was 30 Gy prescribed to the applicator surface. A 2.9% RN rate was observed. The estimated 1 year-LCR was 97.1% and the 1 year-DBP-free survival 73.5%. Median time to DBP was 6.4 (range 1.7-24) months in the subgroup of patients experiencing intracerebral progression. The median OS was 17.5 (0.5-not reached) months with a 1 year-survival rate of 61.3%, which did not not significantly differ from the comparative cohort (p = 0.55 and p = 0.82, respectively).

CONCLUSION

IORT is a safe and effective fast-track approach following BM resection, with comparable long-term outcomes as adjuvant EBRT.

A single-institution retrospective analysis of intraoperative radiation boost during breast-conservation treatment for breast cancer

BACKGROUND

As part of a breast-conservation strategy for breast cancer, there are presently no data from randomized controlled studies on the use of intraoperative radiation (IORT) as a tumor bed boost. The effectiveness and safety of IORT as a boost therapy at a tertiary cancer center were retrospectively reviewed in this study.

METHODS

Patients had breast-conserving surgery from 2012 to 2016 that included staging of the axillary lymph nodes, a single dose of 20 Gy IORT with 50-kV photons, whole-breast irradiation (WBI), and (neo-)adjuvant systemic treatment (if applicable). During the follow-up patients were monitored for the assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 4.03). Results included ipsilateral (IBTR), contralateral (CBE), and distant metastasis-free (DMFS) breast progression-free survival, as well as overall survival (OS).

RESULTS

The 68 patients had a median follow-up of 91.5 months (with a range of 9-125). Most patients (n = 51) had T1 disease and were clinically node negative. Only a small number of individuals had triple negative or high-grade illness. The majority of patients had sentinel node biopsy, and three (4.4%) had to have their tumors removed again since their original margins were positive. Finally, there were no distinct tumor bed margins. Neoadjuvant chemotherapy was administered to ten (14.7%). The median duration from BCS to WBI was 54.5 days, and conventionally fractionated WBI was used to accomplish WBI most frequently (n = 57, 96.6%). IORT was administered in a single 20 Gy dosage. 50 Gy was the median WBI dosage (range 40.05-50.4 Gy). There were no grade 4 adverse events for any patients in. Toxicities following surgery were minimal. There were only one patient with grade 3 toxicity (radiation dermatitis) to observe. Five tumor bed recurrences and two contralateral breast incident each occurred.

CONCLUSION

This work adds to the preliminary evidence already in the literature and supports the use of IORT in boost settings. When randomized trials like TARGIT-B are eventually published, these hopeful findings should be prospectively evaluated.

Outcomes of surgical resection and intraoperative electron radiotherapy for patients with para-aortic recurrences of gastrointestinal and gynecologic malignancies

BACKGROUND

Para-aortic lymph node (PALN) metastases from primary pelvic malignancies are often treated with resection, but recurrence is common. We report toxicity and oncologic outcomes for patients with PALN metastases from gastrointestinal and gynecologic malignancies treated with resection and intraoperative electron radiotherapy (IORT).

METHODS

We retrospectively identified patients with recurrent PALN metastases who underwent resection with IORT. All patients were included in the local recurrence (LR) and toxicity analyses. Only patients with primary colorectal tumors were included in the survival analysis.

RESULTS

There were 26 patients with a median follow up of 10.4 months. The rate of para-aortic local control (LC) was 77% (20/26 patients) and the rate of any cancer recurrence was 58% (15/26 patients). Median time from surgery and IORT to any recurrence was 7 months. The LR rate for those with positive/close margins was 58% (7/12 patients) versus 7% (1/14 patients) for those with negative margins (p = 0.009). 15% (4/26 patients) developed surgical wound and/or infectious complications, 8% (2/26 patients) developed lower extremity edema, 8% (2/26 patients) experienced diarrhea, and 19% (5/26 patients) developed an acute kidney injury. There were no reported nerve injuries, bowel perforations, or bowel obstructions. For patients with primary colorectal tumors (n = 19), the median survival (OS) was 23 months.

CONCLUSIONS

We report favorable LC and acceptable toxicity for patients receiving surgical resection and IORT for a population that has historically poor outcomes. Our data show disease control rates similar to literature comparisons for patients with strong risk factors for LR, such as positive/close margins.

The Efficacy and Safety of Intraoperative Radiotherapy in the Treatment of Recurrent High-Grade Glioma: A Single-Center Prospective Study

BACKGROUND

High-grade gliomas are treated following a standard protocol; however, tumor recurrence is almost inevitable. Recurrent high-grade gliomas have an extremely poor prognosis, and there are no clear treatment guidelines. In this stud, we evaluated the safety and effectiveness of intraoperative radiotherapy (IORT) for recurrent high-grade glioma.

METHODS

In this prospective randomized study begun in April 2018, patients ≥18 years of age with a Karnofsky Performance Status >50 and recurrent high-grade glioma were randomly assigned in a 1:1 ratio to tumor resection and IORT or tumor resection alone.

RESULTS

Twenty-two patients were allocated to the IORT group and 21 to receive surgery only (operation group). Clinical data of 42 enrolled patients were involved in the analysis. The progression-free survival of the IORT group was 9.6 months and of the operation group was 7.3 months (P = 0.018), and the overall survival of the 2 groups was 13.5 months and 10.2 months, respectively (P = 0.054). Univariate and multivariate analysis indicated that preoperative Karnofsky Performance Status >70 and IORT were protective factors for patients with recurrent high-grade glioma. A patient who underwent conventional fractionated radiotherapy within 6 months of receiving IORT died on the ninth day after undergoing tumor resection and IORT because of severe cerebral edema. The total operation time was longer in the IORT group, but there were no differences in intraoperative bleeding or adverse events between the 2 groups.

CONCLUSIONS

IORT with low-energy radiography at a dose of 30-40 Gy is generally safe and effective for patients with recurrent glioma. However, IORT should not be performed for patients who have received conventional fractionated radiotherapy within 6 months.

Dosimetric evaluation of an intraoperative radiotherapy system: a measurement-based and Monte-Carlo modelling investigation

Intraoperative radiotherapy (IORT) is a specialised subset of radiotherapy, where a high radiation dose is delivered to a surgically exposed tumour bed in order to eradicate any remaining cancer cells. The aim of this study was to examine the dose characteristics of the Zeiss Intrabeam IORT device which provides near-isotropic emission of up to 50 kV X-rays. The EGSnrc Monte Carlo (MC) code system was used to simulate the device and percentage depth dose (PDD) data measured with a soft X-ray parallel-plate ionisation chamber were used for model verification. The model provided energy spectra, isodose curves and mean photon energies. In addition, EBT3 Gafchromic film was used to verify the MC model by examining PDDs and 2D dose distributions for various applicators. The differences between MC model and ionisation chamber measurements were within 3% for most points, with a maximum deviation of ~ 9%. Most of the simulated PDD points were within 5% of the film-measured data, with a maximum deviation of ~ 10%. The mean energy of the bare probe was found to be 21.19 keV. The mean photon energy from applicators ranged from 29.00 to 30.85 keV. Results of this study may be useful for future work on creating a system for treatment planning.

Partial breast irradiation: An updated consensus statement from the American brachytherapy society

PURPOSE

In recent years, results with mature follow-up have been reported for several Phase III trials randomizing women to receive whole breast irradiation (WBI) versus varying modalities of partial breast irradiation (PBI). It is important to recognize that these methods vary in terms of volume of breast tissue treated, dose per fraction, and duration of therapy. As such, clinical and technical guidelines may vary among the various PBI techniques.

METHODS

Members of the American Brachytherapy Society with expertise in PBI performed an extensive literature review focusing on the highest quality data available for the numerous PBI options offered in the modern era. Data were evaluated for strength of evidence and published outcomes were assessed.

RESULTS

The majority of women enrolled on randomized trials of WBI versus PBI have been age >45 years with tumor size <3 cm, negative margins, and negative lymph nodes. The panel also concluded that PBI can be offered to selected women with estrogen receptor negative and/or Her2 amplified breast cancer, as well as ductal carcinoma in situ, and should generally be avoided in women with extensive lymphovascular space invasion.

CONCLUSIONS

This updated guideline summarizes published clinical trials of PBI methods. The panel also highlights the role of PBI for women facing special circumstances, such as history of cosmetic breast augmentation or prior breast irradiation, and discusses promising novel modalities that are currently under study, such as ultrashort and preoperative PBI. Updated consensus guidelines are also provided to inform patient selection for PBI and to characterize the strength of evidence to support varying PBI modalities.

Intraoperative radiotherapy versus no radiotherapy for early stage low-risk breast cancer patients undergoing breast-conserving surgery: a propensity score matching study based on the SEER database

PURPOSE

To compare the effect of intraoperative radiotherapy (IORT) and no radiotherapy in early stage low-risk breast cancer patients undergoing breast-conserving surgery.

METHODS

According to the criteria recommended by ASTRO for patients eligible for IORT, we retrospectively selected women with early stage low-risk breast cancer who underwent breast-conserving surgery from 2010 to 2019 from the SEER database. Propensity score matching was used to balance the differences in baseline characteristics. The Kaplan-Meier method was used to calculate the overall survival (OS) and breast cancer-specific survival (BCSS) of patients, and the log-rank test was used to compare the differences.

RESULTS

A total of 20,245 patients were included in the analysis, including 1738 in the IORT group and 18,507 in the no radiotherapy group, with a median follow-up of 41 months. Before matching, the 5-year OS rates of the IORT group and the no radiotherapy group were 95.5% and 85.7% (p < 0.001), respectively, and the 5-year BCSS rates of the two groups were 99.6% and 98.3% (p < 0.001), respectively. After matching, the 5-year OS rates were 95.6% and 90.3% (p < 0.001) in the IORT group and the no radiotherapy group, respectively, and the 5-year BCSS rates were 99.5% and 99.1% (p = 0.028), respectively. Cox multivariate analysis of the original data showed that radiotherapy was an independent prognostic factor for both OS and BCSS (p < 0.05).

CONCLUSIONS

For patients aged 50 years or older with early stage low-risk breast cancer, IORT may be a better option, with improved BCSS compared to the elimination of radiotherapy. The study could not draw conclusions on OS, because underlying diseases may be unevenly distributed between the two groups.

Intraoperative radiotherapy during awake craniotomies: preliminary results of a single-center case series

Awake craniotomies are performed to avoid postoperative neurological deficits when resecting lesions in the eloquent cortex, especially the speech area. Intraoperative radiotherapy (IORT) has recently focused on optimizing the oncological treatment of primary malignant brain tumors and metastases. Herein, for the first time, we present preliminary results of IORT in the setting of awake craniotomies. From 2021 to 2022, all patients undergoing awake craniotomies for tumor resection combined with IORT were analyzed retrospectively. Demographical and clinical data, operative procedure, and treatment-related complications were evaluated. Five patients were identified (age (mean ± standard deviation (SD): 65 ± 13.5 years (y)). A solid left frontal metastasis was detected in the first patient (female, 49 y). The second patient (male, 72 y) presented with a solid metastasis on the left parietal lobe. The third patient (male, 52 y) was diagnosed with a left temporoparietal metastasis. Patient four (male, 74 y) was diagnosed with a high-grade glioma on the left frontal lobe. A metastasis on the left temporooccipital lobe was detected in the fifth patient (male, 78 y). After awake craniotomy and macroscopic complete tumor resection, intraoperative tumor bed irradiation was carried out with 50 kV x-rays and a total of 20 Gy for 16.7 ± 2.5 min. During a mean follow-up of 6.3 ± 2.6 months, none of the patients developed any surgery- or IORT-related complications or disabling permanent neurological deficits. Intraoperative radiotherapy in combination with awake craniotomy seems to be feasible and safe.

Effectiveness and safety of intraoperative radiotherapy (IORT) with low-energy X-rays (INTRABEAM®) for accelerated partial breast irradiation (APBI)

PURPOSE

To evaluate treatment outcomes in patients with early-stage breast cancer (ESBC) treated with targeted intraoperative radiation therapy (IORT) administered as accelerated partial breast irradiation (APBI).

METHODS

Between December 2014 and May 2019, 50 patients diagnosed with ESBC were treated with a 50 kilovoltage (kV) X-ray source with a single dose of 20 Gy using the Intrabeam^® radiotherapy delivery system. All patients were followed prospectively to assess local control (LC), disease-free survival (DFS), cancer-specific survival (CSS), overall survival (OS), radiation-induced toxicity, and cosmetic outcomes. We also evaluated the prognostic implications of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR).

RESULTS

Median follow-up was 53 months. Mean patient age was 70 years. The mean duration of radiation delivery was 22.25 min. Two patients developed a recurrence. One death was recorded. Elevated pretreatment NLR levels were a significant risk factor for mortality (p = 0.0026). The most common treatment-related toxicities were breast induration (30%) and seroma (18%). Five-year LC, DFS, CSS, and OS rates were 97.1%, 93.9%, 100%, and 94.4%, respectively. Cosmesis was excellent or good in most cases (94%).

CONCLUSION

These findings confirm the effectiveness of a single dose of 20 Gy of IORT with the Intrabeam device as APBI. The toxicity profile was good with excellent cosmesis. These results provide further support for the clinical use of APBI in well-selected patients.

Early Therapeutic Interventions for Newly Diagnosed Glioblastoma: Rationale and Review of the Literature

PURPOSE OF REVIEW

Glioblastoma is the commonest primary brain cancer in adults whose outcomes are amongst the worst of any cancer. The current treatment pathway comprises surgery and postoperative chemoradiotherapy though unresectable diffusely infiltrative tumour cells remain untreated for several weeks post-diagnosis. Intratumoural heterogeneity combined with increased hypoxia in the postoperative tumour microenvironment potentially decreases the efficacy of adjuvant interventions and fails to prevent early postoperative regrowth, called rapid early progression (REP). In this review, we discuss the clinical implications and biological foundations of post-surgery REP. Subsequently, clinical interventions potentially targeting this phenomenon are reviewed systematically.

RECENT FINDINGS

Early interventions include early systemic chemotherapy, neoadjuvant immunotherapy, local therapies delivered during surgery (including Gliadel wafers, nanoparticles and stem cell therapy) and several radiotherapy techniques. We critically appraise and compare these strategies in terms of their efficacy, toxicity, challenges and potential to prolong survival. Finally, we discuss the most promising strategies that could benefit future glioblastoma patients. There is biological rationale to suggest that early interventions could improve the outcome of glioblastoma patients and they should be investigated in future trials.

Embedded bleeding detector into a PMMA applicator for electron intraoperative radiotherapy

PURPOSE

The aim of this work is to present a ready to industrialize low-cost and easy-to-install bleeding detector for use in intraoperative electron radiation therapy (IOERT). The detector works in stand-alone mode and is embedded into a translucent polymethylmethacrylate (PMMA) applicator avoiding any contact with the patient, which represent a novelty compared to previous designs. The use of this detector will prevent dose misadministration during irradiation in the event of accumulation of fluids in the applicator.

METHODS

The detector is based on capacitive sensor and wireless power-supply electronics. Both sensor and electronics have been embedded in the applicator, so that any contact with the patient would be avoided. Since access to the tumor can be done through different trajectories, the detector has been calibrated for different tilting angles.

RESULTS

The result of the calibration provides us with a fit curve that allows the interpolation of the results at any angle. Comparison of estimated fluid height vs real height gives an error of 1 mm for tilting angles less than 10° and 2 mm for tilting angles greater than 15°. This accuracy is better than the one required by clinic.

CONCLUSIONS

The performance of the bleeding detector was evaluated in situ. No interference was observed between the detector and the beam. In addition, a user-friendly mobile application has been developed to help the surgical team making decisions before and during irradiation. The measurement provided by the mobile application was stable during the irradiation process.

Intraoperative radiotherapy for glioblastoma: A systematic review of techniques and outcomes

BACKGROUND

Despite multimodality treatment, the prognosis of glioblastoma (GBM) has remained poor. Intraoperative radiation therapy (IORT) offers additional local control by directly applying a radiation source to the resection margin, where most recurrences occur.

METHODS

We performed a systematic review on the oncologic outcomes and toxicities of IORT for GBM in the era of modern external beam radiation therapy (EBRT) and chemotherapy with temozolamide.

RESULTS

Four studies representing 123 patients were included. Majority (81%) were newly diagnosed, and gross total resection was reported in 13-80% of cases. IORT modalities included electrons from a linear accelerator (LINAC) and photons from a 50-kV x-ray device. Median doses were from 12.5 to 20 Gy for electron-based studies and 10-25 Gy for photon-based studies. Adjuvant treatment consisted of 46-60 Gy post-operative EBRT in electron-based studies and the Stupp protocol in photon-based studies. Complications included radiation necrosis (2.8-33%), infection, hematoma, perilesional edema, and wound dehiscence. Median time to local recurrence was 9.9-16 months and the reported overall progression-free survival was 11.2-12.2 months. Median overall survival was 13-14.2 months for the electron-based studies and 13.8-18 months for the photon-based studies.

CONCLUSION

IORT resulted in improved local control and comparable overall survival rates with the Stupp protocol. Although photon-based IORT had better results than electron IORT, this may be due to improvements in other forms of adjuvant treatment rather than the IORT modality itself. The overall effect of IORT on GBM treatment is still inconclusive due to the small number of patients and heterogeneous reporting of data.

In regard to Minniti et al.: Current status and recent advances in resection cavity irradiation of brain metastases-roundup to cover all angles

We read with great interest the recent review, entitled "Current status and recent advances in resection cavity irradiation of brain metastases". It is a comprehensive summary of currently available techniques for treatment of post-resection cavity in patients with this diagnosis. We would like to complement this manuscript by including intraoperative techniques as other viable approaches in the management of these patients.

Health-related quality of life of early-stage breast cancer patients after different radiotherapy regimens

Purpose

To evaluate and compare health-related quality of life (HRQL) of women with early-stage breast cancer (BC) treated with different radiotherapy (RT) regimens.

Methods

Data were collected from five prospective cohorts of BC patients treated with breast-conserving surgery and different RT regimens: intraoperative RT (IORT, 1 × 23.3 Gy; n = 267), external beam accelerated partial breast irradiation (EB-APBI, 10 × 3.85 Gy; n = 206), hypofractionated whole breast irradiation(hypo-WBI, 16 × 2.67 Gy; n = 375), hypo-WBI + boost(hypo-WBI-B, 21–26 × 2.67 Gy; n = 189), and simultaneous WBI + boost(WBI-B, 28 × 2.3 Gy; n = 475).

Women ≥ 60 years with invasive/in situ carcinoma ≤ 30 mm, cN0 and pN0-1a were included. Validated EORTC QLQ-C30/BR23 questionnaires were used to asses HRQL. Multivariable linear regression models adjusted for confounding (age, comorbidity, pT, locoregional treatment, systemic therapy) were used to compare the impact of the RT regimens on HRQL at 12 and 24 months. Differences in HRQL over time (3–24 months) were evaluated using linear mixed models.

Results

There were no significant differences in HRQL at 12 months between groups except for breast symptoms which were better after IORT and EB-APBI compared to hypo-WBI at 12 months (p < 0.001). Over time, breast symptoms, fatigue, global health status and role functioning were significantly better after IORT and EB-APBI than hypo-WBI. At 24 months, HRQL was comparable in all groups.

Conclusion

In women with early-stage breast cancer, the radiotherapy regimen did not substantially influence long-term HRQL with the exception of breast symptoms. Breast symptoms are more common after WBI than after IORT or EB-APBI and improve slowly until no significant difference remains at 2 years posttreatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06314-4.

Intraoperative Radiotherapy for Breast Cancer in Elderly Women

PURPOSE

To evaluate outcomes and postoperative toxicities after intraoperative radiotherapy (IORT) in elderly women.

POPULATION

Women older than 65 years, with infiltrating ductal breast cancer ≤3 cm, expressing estrogen receptor (ER+) without Her2 overexpression, and with negative axillary nodes.

TREATMENT

Treatment consisted of partial mastectomy with a sentinel lymph node biopsy (SLNB) procedure; in case of positive SLNB, IORT was cancelled. IORT consisted in a total dose of 20 Gy in 1 fraction delivered at the surface of the applicator with the Intrabeam® technique.

RESULTS

IORT was planned to be administered to a total of 225 patients but was cancelled for 34 patients during surgery. Thus 191 patients were analyzed; mean age was 76 years, with 57 patients (30%) >80 years. Despite inclusion criteria, 15 had lobular carcinoma and 7 were triple negative. With a median follow-up of 40 months, we observed only 1 local recurrence, located in the skin over the initial tumor. The 5-year local relapse rate was 1.7%. A wound healing delay (>15 days) was observed in 21 patients (11%). Sixty-six patients (35%) had postoperative complications, mainly grade 2, resolving within a few days. Two patients needed surgical drainage for local abscesses. Long-term (>1 year) cosmetic outcome was evaluated in 120 patients and was judged excellent or good in 102 (91%).

CONCLUSION

IORT can be safely given to elderly women, with a good local control rate and without major toxicities.

Intraoperative radiotherapy boost as part of breast-conservation therapy for breast cancer: a single-institution retrospective analysis

Background

There are currently no data from randomized controlled trials on the use of intraoperative radiotherapy (IORT) as a tumor bed boost as part of a breast-conservation approach for breast cancer. This study retrospectively reviewed the safety and efficacy of IORT as a boost treatment at a tertiary cancer center.

Methods

From 2015 to 2019, patients underwent breast-conserving surgery with axillary lymph node staging and a single dose of 20 Gy IORT with 50-kV photons, followed by whole-breast irradiation (WBI) and adjuvant systemic therapy (if applicable). Patients were followed for assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 5.0) at 3–6-month intervals. Outcomes included ipsilateral (IBTR) and contralateral breast progression-free survival (CBE), distant metastasis-free survival (DMFS), and overall survival (OS).

Results

Median follow-up for the 214 patients was 28 (range 2–59) months. Most patients had T1 disease (n = 124) and were clinically node negative. Only few patients had high-grade and/or triple-negative disease. The vast majority of patients underwent sentinel node biopsy, and 32 (15%) required re-resection for initially positive margins. Finally, all tumor bed margins were clear. Nine (4.2%) and 48 (22.4%) patients underwent neoadjuvant and adjuvant chemotherapy, respectively. WBI was predominantly performed as conventionally fractionated WBI (n = 187, 87.4%), and the median time from BCS to WBI was 54.5 days. IORT was delivered with a single dose of 20 Gy. The median WBI dose was 50 Gy (range 29.4–50.4 Gy). No patients experienced grade 4 events; acute grade 3 toxicities were limited to 17 (8%) cases of radiation dermatitis. Postoperative toxicities were mild. After WBI only one case of late grade ≥ 2 events was reported. There were two recurrences in the tumor bed and one contralateral breast event.

Conclusion

This investigation provides additional preliminary data supporting the using of IORT in the boost setting and corroborates the existing literature. These encouraging results should be prospectively validated by the eventual publication of randomized studies such as TARGIT‑B.

Intraoperative radiotherapy vs concurrent chemoradiotherapy in the treatment of patients with locally advanced pancreatic cancer

PURPOSE

The purpose of the multi-institutional retrospective study was to evaluate whether intraoperative radiotherapy (IORT) has advantages in the treatment of patients with locally advanced pancreatic cancer (LAPC) compared with concurrent chemoradiotherapy (CCRT).

PATIENTS AND METHODS

A total of 103 patients with LAPC whom was treated with IORT (Arm A; n = 50) or CCRT (Arm B; n = 53) from 2015.6 to 2016.7 were retrospectively identified. Data on feasibility, toxicity, and overall survival (OS) were evaluated.

RESULTS

Most factors of the two cohorts were similar. The severe adverse events (grade 3 and 4) patients in Arm B were higher than patients in Arm A (34% vs 0%). Disease progression was noted in 38 patients (76%) in Arm A and 37 patients (69.8%) in Arm B. The median survival of patients in Arm A and B were 15.3 months (95% CI, 13.0-17.6 months) and 13.8 months (95% CI, 11.0-16.6 months), respectively. The 1-year survival rate were 66.3% in Arm A (95% CI, 52.3%-80.2%) and 60.9% in Arm B (95% CI, 46.4%-75.4%). There was no significant difference in OS between patients treated with IORT and with CCRT (p = 0.458).

CONCLUSION

Our results demonstrated that patients with LAPC treated with IORT showed fewer adverse events, less treatment time, and high feasibility compared to CCRT. Although, IORT has no advantages in survival and tumor control compared with CCRT.

IOERT versus external beam electrons for boost radiotherapy in stage I/II breast cancer: 10-year results of a phase III randomized study

Background

Intraoperative radiotherapy with electrons (IOERT) boost could be not inferior to external beam radiotherapy (EBRT) boost in terms of local control and tissue tolerance. The aim of the study is to present the long-term follow-up results on local control, esthetic evaluation, and toxicity of a prospective study on early-stage breast cancer patients treated with breast-conserving surgery with an IOERT boost of 10 Gy (experimental group) versus 5 × 2 Gy EBRT boost (standard arm). Both arms received whole-breast irradiation (WBI) with 50 Gy (2 Gy single dose).

Methods

A single-institution phase III randomized study to compare IOERT versus EBRT boost in early-stage breast cancer was conducted as a non-inferiority trial. Primary endpoints were the evaluation of in-breast true recurrences (IBTR) and out-field local recurrences (LR) as well as toxicity and cosmetic results. Secondary endpoints were overall survival (OS), disease-free survival (DFS), and patient’s grade of satisfaction with cosmetic outcomes.

Results

Between 1999 and 2004, 245 patients were randomized: 133 for IOERT and 112 for EBRT. The median follow-up was 12 years (range 10–16 years). The cumulative risk of IBTR at 5–10 years was 0.8% and 4.3% after IOERT, compared to 4.2% and 5.3% after EBRT boost (p = 0.709). The cumulative risk of out-field LR at 5–10 years was 4.7% and 7.9% for IOERT versus 5.2% and 10.3% for EBRT (p = 0.762). All of the IOERT arm recurrences were observed at > 100 months’ follow-up, whereas the mean time to recurrence in the EBRT group was earlier (55.2 months) (p < 0.05). No late complications associated with IOERT were observed. The overall cosmetic results were scored as good or excellent in physician and patient evaluations for both IOERT and EBRT. There were significantly better scores for IOERT at all time points in physician and patient evaluations with the greatest difference at the end of EBRT (p = 0.006 objective and p = 0.0004 subjective) and most narrow difference at 12 months after the end of EBRT (p = 0.08 objective and p = 0.04 subjective analysis).

Conclusion

A 10-Gy IOERT boost during breast-conserving surgery provides high local control rates without significant morbidity. Although not significantly superior to external beam boosts, the median time to local recurrences after IOERT is prolonged by more than 4 years.

Sole adjuvant intraoperative breast radiotherapy in Taiwan: a single-center experience

Introduction

Intraoperative radiotherapy (IORT) is more convenient than standard whole breast external beam radiotherapy (EBRT) as a sole adjuvant radiotherapy for breast cancer. The impact of age on breast cancer course and treatment strategy is still under investigation, and the peak age for breast cancer in Taiwan is much younger than that in Western countries. We aimed to review the oncological outcomes of sole IORT compared with standard EBRT in a country with younger breast cancer patients.

Patients and methods

We reviewed patients with invasive breast cancer who received breast-conserving surgery (BCS) from September 2014 to December 2016. The clinicopathologic characteristics and oncological outcomes of eligible patients who received EBRT or IORT as sole adjuvant radiotherapy after BCS were collected and reviewed.

Results

A total of 170 patients were enrolled with a mean follow-up time of 3.53 ± 0.82 years. The risk of locoregional recurrence was 2.44% for EBRT versus 10.64% for IORT (p = 0.024). IORT was a significant risk factor of locoregional recurrence (p = 0.005). The hazard ratios (HRs) for locoregional recurrence in the IORT group compared with the EBRT group were significantly higher in non-suitable risk group patients (HR = 7.02, p = 0.009) and in patients under 50 years old (HR = 10.42, p = 0.011).

Conclusions

Locoregional recurrence was significantly higher in patients who received IORT than in those who underwent EBRT. IORT should not be used alone in patients under 50 years old who do not belong to a suitable group.

Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis

BACKGROUND

In recent years, intraoperative radiotherapy (IORT) has been increasingly used for the treatment of rectal cancer. However, the efficacy and safety of IORT for the treatment of rectal cancer are still controversial.

AIM

To evaluate the value of IORT for patients with rectal cancer.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science databases, and conference abstracts and included randomized controlled trials and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

RESULTS

In this study, 3 randomized controlled studies and 12 observational studies were included with a total of 1460 patients, who are mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126); 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713), fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

CONCLUSION

The advantage of IORT is mainly reflected in 5-year local control, but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.

Outcome of Soft-tissue Reconstruction in the Setting of Combined Preoperative and Intraoperative Radiotherapy for Extremity Soft-tissue Sarcomas

BACKGROUND/AIM

Reconstruction for soft-tissue sarcomas is complex and often uses soft-tissue flaps. To preserve critical structures, intraoperative radiotherapy (IORT) can be used to boost the total dose to these critical structures and close margins; however, there are limited data on the outcome of soft-tissue reconstruction in patients treated with IORT.

PATIENTS AND METHODS

Twenty patients received IORT with soft-tissue flap coverage. There were 14 tumors of the lower extremities and six of the upper, including seven free-flaps and 13 pedicle flaps. Mean preoperative and IORT doses were 49.4 Gy and 10.4 Gy, respectively, with a mean total dose of 59.8 Gy.

RESULTS

Seven (35%) patients had a complication, most commonly an infection (n=4, 27%). Total flap loss occurred in one treated with pedicle flap. Four (20%) patients suffered a radiation-associated fracture. At the final follow-up, the mean Musculoskeletal Tumor Society Score was 75±11%.

CONCLUSION

Complications and postoperative fractures were common with IORT, however, there were no cases requiring amputation.

Long-term outcome after combined kyphoplasty and intraoperative radiotherapy (Kypho-IORT) for vertebral tumors

INTRODUCTION

The spine represents the site which is most frequently affected by bone metastases in patients with systemic cancer. Of all local treatment options, combined kyphoplasty and intraoperative radiotherapy (Kypho-IORT) provides both, instantaneous stabilization and immediate pain relief. We here report on the long-term outcomes of the largest cohort treated with Kypho-IORT to date.

METHODS

Between 2009 and 2019 a total of 104 patients underwent Kypho-IORT to vertebral tumors in the thoracic, lumbar, or sacral spine with transpedicular kyphoplasty and intraoperative irradiation with a needle-shaped electronic brachytherapy source at our center. Patients were treated either on trial, within the prospective Kypho-IORT studies (NCT01280032 and NCT02773966), or, after completion of the study, off trial but compliant with the study protocol. Follow-up and imaging with computed tomography (CT) or magnetic resonance imaging was scheduled after 3 and 6 months and then bi-annually.

RESULTS

A total of 143 vertebrae (89 thoracic spine, 53 lumbar spine, and 1 sacral spine) were treated in 104 patients. The median follow-up was 14.5 months (range 0.4-109). Local progression occurred in 10 patients (10 vertebrae) after a median time of 22.3 months (range 1.5-73) resulting in local control rates of 97.1, 95.9, and 94.2% at 6, 12, and 24 months, respectively. Overall survival was 74.6, 61.7, and 50.3% at 6, 12, and 24 months, respectively. A single serious adverse event was reported.

CONCLUSION

In addition to immediate pain reduction and stabilization, Kypho-IORT shows excellent long-term local control with minimal side effects.

[Intraoperative radiotherapy in abdominal surgery-Own experiences]

Hintergrund

Die intraoperative Radiotherapie (IORT) kann bei lokal weit fortgeschrittenen Tumoren und zu erwartender bzw. nicht vermeidbarer R1-Situation ergänzend zur chirurgischen Resektion eingesetzt werden. Ziel ist eine verbesserte lokale Tumorkontrolle und damit ein besseres Langzeitüberleben. Indikationen sind sowohl primäre intraabdominelle und retroperitoneale Tumoren als auch Rezidivtumoren. Im Rahmen der vorliegenden Arbeit werden die eigenen Erfahrungen mit der Durchführung einer IORT bei viszeralchirurgischen Resektionen zusammengefasst.

Methodik

Patienten, die von Januar 2008 bis Dezember 2018 eine IORT kombiniert mit abdomineller Tumorresektion in der Klinik für Allgemein- und Viszeralchirurgie des Universitätsklinikums Freiburgs erhalten hatten, wurden in diese Arbeit eingeschlossen und hinsichtlich Kurz- und Langzeitergebnisse evaluiert.

Ergebnisse

Die häufigste Indikation zur Durchführung einer IORT stellten Sarkome gefolgt von Rektum- und Analkarzinomen dar. Die mediane angewandte Strahlendosis der IORT betrug 15 Gy (8–19 Gy). Bei einem medianen „comprehensive complication index“ (CCI) von 11,9 traten bei 24 % der Patienten Komplikationen (Dindo-Clavien ≥ °III) auf. Die 90-Tage-Mortalität betrug 0 %. Besonders für Analkarzinomrezidive war die lokale Kontrolle nach einem Jahr trotz R0-Resektion unzureichend.

Schlussfolgerung

In unserem Patientenkollektiv war die IORT mit vertretbarer Morbidität einsetzbar. Dennoch sind Indikationsstellung und Patientenselektion kritische Punkte für die Durchführung der Behandlung. Der Effekt der IORT zur Verbesserung der lokalen Kontrolle und damit auch des Langzeitüberlebens sollte in weiteren Studien evaluiert werden.

Surgical resection, intraoperative radiotherapy and immediate plastic reconstruction: A good option for the treatment of distal extremity soft tissue sarcomas

Aim

To show three patients with soft tissue sarcomas of distal extremities conservatively treated after tumor-board discussion, involving margin-free surgery, exclusive intraoperative radiotherapy, and immediate reconstruction.

Background

Current guidelines show clear and robust recommendations regarding the composition of the treatment of sarcomas of extremities. However, little evidence exists regarding the application of these treatments depending on the location of the primary neoplasia. Tumors that affect the distal extremities present different challenges and make multidisciplinary discussions desirable.

Methods/Results

We reported 3 patients who were approached with a conservative intention, after tumor board recomendation. The goals from the treatment performed were aesthetic and functional preservation, while enruring locoregional control. We had wound healing complications in 2 of the cases, requiring additional reconstruction measures. Patients are followed up for 24, 20 and 10 months; local control is 100%, and functional preservation is 100%.

Conclusions

Despite being a small series, it was sufficient to illustrate successful multidisciplinary planning, generating a therapeutic result with improved quality of life for patients who had an initial indication for extremity amputation.

Efficacy analysis of intraoperative radiotherapy in patients with early-stage breast cancer

Background

To analyze the clinical efficacy of intraoperative radiotherapy (IORT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer (BC), and to investigate the relationship between its influencing factors and clinical efficacy and prognosis.

Methods

A total of 73 patients with early-stage BC who underwent IORT after BCS in our hospital were selected in this research.

Results

Kaplan-Meier survival analysis was used to analyze the related factors of BCS and IORT of disease-free survival (DFS) and overall survival (OS). It was found that only age (χ² = 14.035, P = 0.003) was statistically positively correlated with the patient’s DFS, and local recurrence and metastasis rate and mortality were higher in patients over 70 years old. Log rank test was used to analyze multiple factors. Only the diameter of the applicator (χ² = 70.378, P < 0.05) was statistically significant with wound complications, and the larger the diameter, the higher incidence of wound complications. The remaining risk factors did not increase the incidence of wound complications. COX multivariate analysis showed that age was an independent risk factor for DFS rate and the risk factor had no significant effect on the OS rate of patients undergoing IORT after BCS.

Conclusions

IORT may be a safe form of treatment for the selected patients with early-stage BC, and can achieve satisfactory esthetic effect. Larger applicator diameters may increase the incidence of wound complications. Age is an independent risk factor for DFS in early-stage BC patients undergoing IORT after BCS.

ESTRO/ACROP IORT recommendations for intraoperative radiation therapy in primary locally advanced rectal cancer

Carcinoma of the rectum is a heterogeneous disease. The clinical spectrum identifies a subset of patients with locally advanced tumours that are close to or involve adjoining structures, such as the sacrum, pelvic sidewalls, prostate or bladder. Within this group of patients categorized as "locally advanced", there is also variability in the extent of disease with no uniform definition of resectability. A practice-oriented definition of a locally advanced tumour is a tumour that cannot be resected without leaving microscopic or gross residual disease at the resection site. Since these patients do poorly with surgery alone, irradiation and chemotherapy have been added to improve the outcome. Intraoperative irradiation (IORT) is a component of local treatment intensification with favourable results in this subgroup of patients. International guidelines (National Comprehensive Cancer Network (NCCN) guidelines) currently recommend the use of IORT for rectal cancer resectable with very close or positive margins, especially for T4 and recurrent cancers. We report the ESTRO-ACROP (European Society for Radiotherapy and Oncology - Advisory Committee on Radiation Oncology Practice) recommendations for performing IORT in primary locally advanced rectal cancer.

[Safety and short-term efficacy analysis of breast-conserving surgery combined with intraoperative radiotherapy for early-stage breast cancer]

Objective: To analyze the safety and short-term efficacy of breast-conserving surgery combined with intraoperative radiotherapy for early-stage breast cancer. Methods: A total of 101 consecutive patients who received breast-conserving surgery plus intraoperative radiotherapy were recruited to summarize the recent follow-up results and clinicopathological data. Univariate analysis and Logistic regression model were used to evaluate the factors affecting the postoperative adverse reactions and cosmetic effects. Results: Among 101 patients, 4 patients had recurrence or metastasis. The 3-years disease free survival rate was 94.9%, and the 3-years cumulative recurrence rate was 5.1%. Univariate analysis showed that the menstrual status and postoperative whole breast radiotherapy were associated with the postoperative adverse reactions (P<0.05). The T stage and applicator diameter were associated with the cosmetic effect (P<0.05). Multivariate analysis indicated that the diameter of the applicator (OR=3.701, P=0.026) and postoperative whole breast radiotherapy (OR=5.962, P=0.005) were independent factors for the postoperative adverse reactions, and the diameter of the applicator (OR=2.522, P=0.037) was an independent factor for the cosmetic effect. Conclusion: Breast-conserving surgery combined with intraoperative radiotherapy shows safety and good short-term efficacy in low-risk early-stage breast cancer.

a Case Report and Review of the Literature

Appendiceal mucinous adenocarcinoma is a term that was given for invasive appendiceal tumors. It is always present with pseudomyxoma peritonei which is a complex disease. These tumors have the tendency to surround the primary tumor then extend primarily and extensively all over the peritoneal cavity as the primary site of metastases. The invasion through the abdominal wall muscles is rare but the penetration and passing through these muscles to the subcutaneous tissue are extremely rare. A 62-year-old male patient known to have pseudomyxoma peritonei presented with gluteal abscess. After 2 weeks from the abscess drainage, the patient underwent cytoreductive surgery (CRS) combined with intraoperative radiotherapy (IORT) and hyperthermic intraperitoneal chemotherapy (HIPEC). He tolerated the operation well and discharged home in a good condition. Even with extensive appendiceal mucinous neoplasms presented with the penetration of the abdominal wall muscles, still aggressive management should be considered.

INTRABEAM intraoperative radiotherapy combined with portal vein infusion chemotherapy for treating hepatocellular carcinoma with portal vein tumor thrombus

Background

Portal vein tumor thrombus (PVTT) is common in hepatocellular carcinoma (HCC). Recent studies indicate that more aggressive treatments, including surgical resection or locoregional treatment, may benefit selected HCC patients with PVTT. External radiation therapy and infusion chemotherapy were found to achieve good outcomes; however, the use of low-energy x-ray radiation system (INTRABEAM), intraoperative radiation therapy, and portal vein infusion chemotherapy for PVTT has not been reported.

Case summary

We present a case of HCC with PVTT. The patient underwent hemihepatectomy and thrombectomy along with intraoperative radiotherapy (IORT) using a portable INTRABEAM radiation system. Subsequently, to treat PVTT, portal vein infusion chemotherapy with FOLFOX (leucovorin [Folinic acid], fluorouracil, and oxaliplatin) regimen was administered. There were no obvious post-operative complications. After 20 months follow-up period, no obvious tumor recurrence had been observed, and PVTT gradually disappeared completely.

Conclusions

IORT using the INTRABEAM radiation system combined with portal vein infusion chemotherapy is promising for select patients with PVTT.

Phantom development for daily checks in electron intraoperative radiotherapy with a mobile linac

PURPOSE

IORT with mobile linear accelerators is a well-established modality where the dose rate and, therefore, the dose per pulse are very high. The constancy of the dosimetric parameters of the accelerator has to be checked daily. The aim of this work is to develop a phantom with embedded detectors to improve both accuracy and efficiency in the daily test of an IORT linac at the surgery room.

METHODS

The developed phantom is manufactured with transparent polymethyl methacrylate (PMMA), allocating 6 parallel-plate chambers: a central one to evaluate the on-axis beam output, another on-axis one placed at a fixed depth under the previous one to evaluate the energy constancy and four off-axis chambers to evaluate the flatness and symmetry. To analyse the readings a specific application has been developed.

RESULTS

For all chambers and energies, the mean saturation and polarization corrections were smaller than 0.7%. The beam is monitored at different levels of the clinical beam. Output, energy constancy and flatness correlate very well with the correspondent values with the complete applicator. During the first six months of clinical use the beam dosimetric parameters showed excellent stability.

CONCLUSIONS

A phantom has been developed with embedded parallel plate chambers attached to the upper applicator part of an IORT linac. The phantom allows a very efficient setup reducing the time to check the parameters. It provides complete dosimetric information (output, energy and flatness) with just one shot and using ionization chambers with minimum saturation effect, as this highly pulsed beam requires.

Intraoperative radiation therapy (IORT) for soft tissue sarcoma - ESTRO IORT Task Force/ACROP recommendations

PURPOSE

To describe guidelines for the use of intraoperative radiation therapy (IORT) in the treatment of soft-tissue sarcomas (STS).

METHODS

A panel of experts in the field performed a systematic literature review, supplemented their clinical experience and developed recommendations for the use of IORT in the treatment of STS.

RESULTS

Based on the evidence from the systematic literature review and the clinical experience of the panel members, recommendations regarding patient selection, incorporation into multimodal treatment concepts and the IORT procedure itself are made. The rationale for IORT in extremity and retroperitoneal STS is summarized and results of the major series in terms of patient and treatment characteristics, oncological outcome and toxicity are presented. We define surgical factors, volumes for irradiation, technical requirements, dose prescription, recording and reporting, treatment delivery and care during the course of IORT covering the main IORT techniques used for the treatment of STS. In extremity STS, evidence originates from a few small prospective and mainly from retrospective single centre studies. Based on those reports, IORT containing-approaches result in very high local control rates with low rates of acute and late toxicity. In retroperitoneal sarcomas, evidence is derived from one prospective randomized trial, a few prospective and a large number of retrospective studies. The randomized trial compared IORT combined with moderate doses of postoperative external-beam radiation therapy (EBRT) to high-dose postoperative EBRT alone after gross total resection, clearly favouring the IORT-containing approach. These results have been confirmed by the prospective and retrospective studies, which similarly showed high local control rates with acceptable toxicity, mainly favouring combinations of preoperative EBRT and IORT.

CONCLUSIONS

IORT-containing approaches result in high rates of local control with low to acceptable toxicity rates. Based on the available evidence, we made recommendations for the use of IORT in STS. Clinicians and researchers are encouraged to use these guidelines in clinical routine as well as in the design of future trials.

ESTRO/ACROP IORT recommendations for intraoperative radiation therapy in locally recurrent rectal cancer

Multimodal strategies have been implemented for locally recurrent rectal cancer scheduled for complete surgical resection. Irradiation and systemic therapy have been added to improve the oncological outcome, as surgery alone was associated with a poor prognosis. Intraoperative irradiation (IORT) is a component of irradiation intensification. Long-term cancer control and a higher survival rate were consistently reported in patients who had IORT as a component of their multidisciplinary treatment. The experience reported by expert IORT groups is reviewed and recommendations to guide clinical practice are explained in detail.

Low-kilovolt x-ray intraoperative radiotherapy for pT3 locally advanced colon cancer: a single-institution retrospective analysis

Background

Patients with locally advanced colon cancer (LACC) treated with surgery had a high risk of local recurrence. The outcomes can vary significantly among patients with pT3 disease. This study was undertaken to assess whether low-kilovolt (kV) x-ray intraoperative radiotherapy (IORT) can achieve promising results compared with electron beam IORT (IOERT) and whether specific subgroups of patients with pT3 colon cancer may benefit from low-kV x-ray IORT.

Methods

We retrospectively reviewed 44 patients with pT3 LACC treated with low-kV x-ray IORT. Clinicopathologic characteristics were analyzed to identify patients that could potentially benefit from low-kV x-ray IORT. The Kaplan-Meier survival analysis was used to assess overall survival (OS) and progression-free survival (PFS). Correlation analysis was used to discover the association of multiple factors to the results of treatment represented by the values of OS and PFS.

Results

The median follow-up of patients was 20.5 months (range, 6.1–38.8 months). At the time of analysis, 38 (86%) were alive and 6 (14%) had died of their disease. The 3-year Kaplan-Meier of PFS and OS for the entire cohort was 82.8% and 82.1%, respectively. At median follow-up, no in-field failure within the low-kV x-ray IORT field had occurred. Locoregional and distant failure had occurred in 2 (5%) patients each. The rate of perioperative 30-day mortality was 0%, and the morbidity rate was 11%. Five patients experienced 7 complications, including 4 early complications (30 days) and three late complications (> 30 days) leading early and late morbidity rates of 9% and 7%, respectively.

Conclusion

Patients with LACC who had undergone an additional low-kV x-ray IORT can achieve encouraging locoregional control, PFS, OS, and distant control without an increase in short-term or long-term complications. Low-kV x-ray IORT can be considered as part of management in pT3 LACC.

Breast-conserving surgery with intraoperative radiotherapy in recurrent breast cancer: the patient's perspective

Purpose

When ipsilateral breast-tumor recurrence (IBTR) following breast-conserving surgery (BCS) occurs, the cure of a potentially life-threatening disease is the main goal. If, however, this is diagnosed early, prognosis is still good and patient-reported outcomes become more important. Despite the fact that many patients would prefer a further BCS, international breast cancer guidelines still recommend mastectomy, mainly because previous radiation implies limited options. Our comparative study evaluates the long-term quality-of-life and outcome in patients with IBTR who received BCS plus intraoperative radiotherapy (IORT) versus mastectomy.

Methods

Patients with IBTR were retrospectively divided into three groups according to the local treatment: group 1 (n = 26) was treated with BCS + IORT; group 2 (n = 35) received a standard mastectomy; group 3 (n = 52) had a mastectomy with subsequent reconstruction. Outcomes were analyzed after a mean follow-up of 5 years after IBTR. Quality-of-life was evaluated by the validated questionnaire BREAST-Q in 50 patients who fulfilled the inclusion criteria.

Results

Quality-of-life scores varied within the groups, ranging from 51.4 to 91.3 (out of 100 points). We observed satisfactory scores in all items, with no statistical difference within the groups. Disease-free survival of all groups did not statistically differ, and overall mortality was very low (0.9%). The postinterventional complication rate was lower after BCS (19.2% versus 34.3% after mastectomy and 30.8% after mastectomy with reconstruction).

Conclusion

For patients with previous surgery and radiation who demand a second BCS in the recurrent situation, this surgical technique can be offered in combination with IORT. Our long-term results imply oncological safety, lower complication rate, and good patient satisfaction.

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

•

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

•

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

•

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

•

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

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

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

Intraoperative radiotherapy for resectable advanced lower rectal cancer-final results of a randomized controlled trial (UMIN000021353)

AIM

Pelvic autonomic nerve preservation (PANP) is useful to preserve voiding and sexual function after rectal cancer surgery. The aim of this study was to investigate the benefit of intraoperative radiotherapy (IORT) to have complete PANP without affecting oncological outcomes.

METHODS

Patients undergoing potentially curative resection of the rectum were included. They were randomized to intraoperative radiotherapy of the completely preserved bilateral pelvic nerve plexuses (IORT group) or the control group without IORT, but with limited nerve preservation. The primary endpoint was pelvic sidewall recurrence. Moreover, patients' clinicopathologic parameters, postoperative complications, voiding function, and other oncologic outcomes were compared.

RESULTS

From 79 patients, three were excluded from analysis, resulting in 38 patients in each group. Patients' demographic and pathological parameters were well balanced between the two groups. The trial was terminated prematurely in July 2017, because distant metastasis-free survivals were found to be significantly worse in the IORT group compared to the control group (odds ratio 2.554; 95% CI, 1.041 ~ 6.269; p = 0.041). Neither overall survival nor pelvic sidewall recurrence did differ between the two groups (overall survival: odds ratio 1.264; 95% CI, 0.523~3.051; p = 0.603/pelvic sidewall recurrence; odds ratio 1.350; 95% CI, 0.302~6.034; p = 0.694). Postoperative complications did not differ between the groups; however, the urinary function was significantly better in the IORT group in the short and long term.

CONCLUSION

With the aid of IORT, complete PANP can be done without increase of pelvic sidewall recurrence; however, IORT may increase the incidence of distant metastases. Therefore, IORT cannot be recommended as a standard therapy to compensate less radical resection for advanced lower rectal cancer.

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

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

The role of intraoperative radiation therapy in resectable pancreatic cancer: a systematic review and meta-analysis

Purpose

Several studies investigating the role of intraoperative radiotherapy (IORT) in the treatment of resectable pancreatic cancer (PC) have been published; however, their results remain inconsistent. By conducting a systematic review and meta-analysis, this study aimed to compare clinical outcomes in patients with resectable PC who underwent surgery with or without IORT.

Methods and materials

The MEDLINE/PubMed, EMBASE, and Cochrane Library databases were searched to identify relevant studies published up to February 28, 2019. The main outcome measures included median survival time (MST), local recurrence (LR), postoperative complications, and operation-related mortality. Pooled effect estimates were obtained by performing a random-effects meta-analysis.

Results

A total of 1095 studies were screened for inclusion, of which 15 studies with 834 patients were included in the meta-analysis. Overall, 401 patients underwent pancreatic resection with IORT and 433 underwent surgery without IORT. The pooled analysis revealed that IORT group experienced favorable overall survival (median survival rate [MSR], 1.20; 95% confidence interval [CI], 1.06–1.37, P = 0.005), compared with patients who did not receive IORT. Additionally, the pooled data showed a significantly reduced LR rate in the IORT group compared with that in the non-IORT group (relative risk [RR], 0.70; 95% CI, 0.51–0.97, P = 0.03). The incidences of postoperative complications (RR, 0.95; 95% CI, 0.73–1.23) and operation-related mortality (RR, 1.07; 95% CI, 0.44–2.63) were similar between the IORT and non-IORT groups.

Conclusion

IORT significantly improved locoregional control and overall survival in patients with resectable PC, without increasing postoperative complications and operation-related mortality rates.

Toxicity and cosmetic outcome after hypofractionated whole breast irradiation and boost-IOERT in early stage breast cancer (HIOB): First results of a prospective multicenter trial (NCT01343459)

BACKGROUND AND PURPOSE

To assess the role of intraoperative radiation with electrons (IOERT) as tumor bed boost followed by hypofractionated whole breast irradiation (HWBI) after breast conserving surgery (BCS) of patients with low to intermediate risk breast cancer focusing on acute/late toxicity and cosmetic outcome.

MATERIAL AND METHODS

In 2011, a prospective multicenter trial (NCT01343459) was started. Treatment consisted of BCS, IOERT (11.1 Gy) and HWBI (40.5 Gy in 15 fractions). In a single-arm design, 5-year IBR-rates are benchmarked by a sequential ratio test (SQRT) against best published evidences in 3 age groups (35-40 y, 41-50 y, >50 y). Acute/late toxicity and cosmesis were evaluated by validated scorings systems.

RESULTS

Of 627 eligible patients, 44 were excluded, leaving 583 to analyze. After a median follow-up (FUP) of 45 months (range 0-74), for acute effects CTCAE-score 0/1 was noted in 91% (end of HWBI) and 92% (4 weeks later), respectively. Late toxicity Grading 0/1 (mean values, ranges) by LENT-SOMA criteria were observed in 92.7% (89-97.3) at 4/5 months, rising to 96.5% (91-100) at 6 years post HWBI. Baseline cosmesis after wound healing prior to HWBI was scored as excellent/good in 86% of cases by subjective (patient) and in 74% by objective (doctor) assessment with no impairment thereafter.

CONCLUSIONS

Acute and late treatment tolerance of a combined Boost-IOERT/HWBI regimen is excellent in short/mid-term assessment. Postoperative cosmetic appearance is not impaired after 3 years FUP.

Accelerated Partial Breast Irradiation: A New Standard of Care?

Background

Breast-conserving therapy including lumpectomy and adjuvant whole breast irradiation (WBI) has become the standard therapy for early-stage breast cancer (EBC). Without WBI, the recurrence rate is significantly increased. However, when selecting patients at a low a priori risk of local recurrence only a small breast-cancer-specific mortality benefit, but no overall survival improvement, was detected for WBI. As most recurrences occur close to the lumpectomy cavity, accelerated partial breast irradiation (APBI) delivered exclusively to a limited volume of tissue around the initial lumpectomy site, has gained increased attention and is now discussed as an alternative to WBI for selected EBC patients.

Summary

Numerous techniques for APBI (interstitial brachytherapy, external beam-based APBI, intraoperative radiotherapy, MR-guided radiotherapy) allow treatment delivery in a shorter period of time, and radiation oncologists expect to further reduce side effects by using these new techniques, with improvements in cosmetics and quality of life. In this review, we aim to describe the existing evidence for the feasibility and effectiveness of different APBI techniques used in modern radiotherapy.

Key Messages

APBI has provided outcomes similar to WBI combined with potentially reduced toxicity. While appropriate patient selection persists to be crucial for acceptable recurrence rates, the precise definition of patients suitable for APBI remains a matter of discussion. As long-term data are often still lacking, special attention should be paid to late side effects and long-term outcomes. Decision-making on appropriate treatment techniques should take into account not only local control rates, but also the impact on the patient's quality of life.

Intraoperative radiotherapy for breast cancer treatment efficiently targets the tumor bed preventing breast adipose stromal cell outgrowth

OBJECTIVES

Mesenchymal stromal cells (MSC) in bone marrow have been shown to be radioresistant, which is related to pronounced DNA repair mechanisms. Intraoperative radiotherapy (IORT) during breast-conserving surgery for early breast cancer is an innovative technique applying low energy x‑ray to the tumor bed immediately after removal of the tumor. IORT is considered to reduce the risk of local tumor recurrence by directly targeting cells of the tumor bed and altering the local microenvironment. Aim of this study was to investigate whether IORT affects the outgrowth potential of breast adipose tissue-derived MSC (bASC) as part of the tumor bed.

MATERIALS AND METHODS

After surgical tumor resection, biopsies of the tumor bed were taken before (pre IORT) and after IORT (post IORT) and processed applying well-established protocols for ASC isolation and characterization.

RESULTS

In all, 95% of pre IORT tumor bed samples yielded persistently outgrowing bASC with typical ASC characteristics: fibroblastoid morphology, proliferation, adipogenic and osteogenic differentiation and ASC surface marker expression. However, none of the post IORT samples yielded persistent outgrowth of bASC.

CONCLUSIONS

After breast-conserving surgery, approximately 90% of local recurrences emerge in close proximity to the initial tumor bed, potentially reflecting a significant contribution of the tumor bed to relapse. Our data show that IORT, besides the proven effect on breast cancer cells, efficiently modifies the tumor environment by having an impact on tumor bed bASC. This effect on tumor bed stromal cells might contribute to reduce the risk of tumor relapse and metastases.

Intraoperative radiotherapy as an immediate adjuvant treatment of rectal cancer due to limited access to external-beam radiotherapy

BACKGROUND

Neoadjuvant external-beam radiotherapy (EBRT) with concomitant chemotherapy is the current standard-of-care for locally-advanced rectal cancer. Intraoperative radiotherapy (IORT) is to date only recommended for pelvic recurrences or incompletely resectable tumors. We here report on patients with stage II/III rectal cancer that were treated with IORT in a regional Russian university center due to limited access to EBRT.

METHODS

We retrospectively analyzed data from patients that were diagnosed with locally-advanced rectal cancer and underwent surgery from December 2012 to October 2016 at a regional oncological center in Russia (Krasnodar). During this period, access to EBRT was limited due to a temporary lack of a sufficient number of EBRT facilities. Patients unable to travel to a distant radiotherapy site received IORT alone, those that could travel received neoadjuvant external beam (chemo-) radiotherapy. Factors of interest were tumor stage, tumor differentiation, resection status, surgery type and neoadjuvant or adjuvant chemotherapy. We assessed local progression-free survival (L-PFS), PFS and overall survival (OS).

RESULTS

A total of 172 patients were included in this analysis. Of those, 92 (53.5%) were treated with IORT alone (median dose: 15 Gy [8.4-17 Gy]) and 80 (46.5%) received both neoadjuvant EBRT (median dose: 50.4 Gy [40-50.4 Gy]) and IORT (median dose: 15 Gy [15-17 Gy]). The median age was 65 years [33-82]. The median follow-up was 23 months [0-63 months]. The incidence of toxicity was low in both groups with an overall complication rate of 5.4%. Local PFS at 4 years was comparable with 59.4% in the IORT group and 65.4% in the IORT/EBRT group (p = 0.70). Similarly, there was no difference in OS or PFS (p = 0.66, p = 0.51, respectively).

CONCLUSIONS

IORT is a valuable option for patients with locally-advanced rectal cancer in the absence of access to EBRT.