Combined modality therapy including intraoperative electron irradiation for locally recurrent colorectal cancer

First clinical application of image-guided intraoperative electron radiation therapy with real time intraoperative dose calculation in recurrent rectal cancer: technical procedure

Intraoperative radiation therapy (IORT) is a radiation technique applying a single fraction with a high dose during surgery. We report the first abdomino-pelvic application of an image-guided intraoperative electron radiation therapy with intraoperative real time dose calculation based on the individual intraoperative patient anatomy. A patient suffering from locoregionally recurrent rectal cancer after treatment with neoadjuvant re-chemoradiation was chosen for this approach. After surgical removal of the recurrence, an adequate IORT applicator was placed as usual. A novel mobile imaging device (ImagingRing, MedPhoton) was positioned around the patient covering the region to be treated with the IORT-applicator in place. It allowed the acquisition of three-dimensional intraoperative cone-beam computed tomography images suitable for dose calculation using an automated scaling (heuristic object and head scatter as well as hardening corrections) of Hounsfield units. After image acquisition confirmed the correct applicator position, the images were transferred to our treatment planning system for intraoperative dose calculation. Treatment could be accomplished using the calculated dose distribution. We herein describe the details of the procedure including necessary adjustments in the typically used IORT equipment and work flow. We further discuss the pros and cons of this new approach generally overcoming a decade long limitation of IORT procedures as well as future perspectives regarding IORT treatments.

A prospective case series assessing the Imperial College London intraoperative radiotherapy protocol for advanced rectal cancer: an IDEAL phase 2a study

AIM

Intraoperative radiotherapy (IORT) decreases local recurrence rates for advanced rectal cancer. Nevertheless, utilization of IORT is limited due to the associated logistical and financial challenges. The aim of this study is to describe the development and delivery of a novel IORT protocol for advanced rectal cancer that overcomes these difficulties in the context of the early phase of an IDEAL 2a study. The primary outcome measure was the ability to deliver IORT using this novel protocol with IORT-related toxicity as the secondary outcome measure.

METHOD

Consecutive patients with advanced rectal cancer expected to have involved (R1) resection margins were enrolled. After resection, 12 Gy low-energy photon IORT was delivered using the Axxent device with a custom-designed elliptical spherical balloon applicator.

RESULTS

Six patients with a median age of 47 years (range 33-88 years; five women) were enrolled between 2018 and 2019. The indication was advanced cancer in four patients and atypical invasive pelvic side wall lymph nodes in two. IORT was successfully delivered in all cases. No toxicity was encountered. Three advanced cancer patients had R1 resection and one had complete resection (R0); resection margin status could not be established for the two lymph node cases. Five patients were alive at 3.4 (2.9-4.1) year follow-up. None of the R1 cases recurred.

CONCLUSION

This is the first study to describe a novel IORT protocol using low-energy photon IORT for advanced rectal cancer. IORT could be delivered in all cases and no IORT-related toxicity was encountered. Available oncological outcome data are encouraging, but further studies will be necessary to determine the oncological effectiveness of this protocol.

Comparing Oncologic Outcomes and Toxicity for Combined Modality Therapy vs. Carbon-Ion Radiotherapy for Previously Irradiated Locally Recurrent Rectal Cancer

No standard treatment paradigm exists for previously irradiated locally recurrent rectal cancer (PILRRC). Carbon-ion radiotherapy (CIRT) may improve oncologic outcomes and reduce toxicity compared with combined modality therapy (CMT). Eighty-five patients treated at Institution A with CIRT alone (70.4 Gy/16 fx) and eighty-six at Institution B with CMT (30 Gy/15 fx chemoradiation, resection, intraoperative electron radiotherapy (IOERT)) between 2006 and 2019 were retrospectively compared. Overall survival (OS), pelvic re-recurrence (PR), distant metastasis (DM), or any disease progression (DP) were analyzed with the Kaplan-Meier model, with outcomes compared using the Cox proportional hazards model. Acute and late toxicities were compared, as was the 2-year cost. The median time to follow-up or death was 6.5 years. Median OS in the CIRT and CMT cohorts were 4.5 and 2.6 years, respectively (p ≤ 0.01). No difference was seen in the cumulative incidence of PR (p = 0.17), DM (p = 0.39), or DP (p = 0.19). Lower acute grade ≥ 2 skin and GI/GU toxicity and lower late grade ≥ 2 GU toxicities were associated with CIRT. Higher 2-year cumulative costs were associated with CMT. Oncologic outcomes were similar for patients treated with CIRT or CMT, although patient morbidity and cost were lower with CIRT, and CIRT was associated with longer OS. Prospective comparative studies are needed.

The Use of Intraoperative Radiation Therapy (IORT) in Multimodality Management of Cancer Patients: a Single Institution Experience

BACKGROUND

Intraoperative radiation therapy (IORT) is a highly conformal type of radiation therapy given at time of surgery aiming for better tumor local control. It increases the tumor radiation dose without exceeding normal tissues tolerance doses.

PURPOSE

To assess the feasibility of IORT and short-term toxicities in patients with different cancer sites treated with multidisciplinary protocol including IORT.

PATIENTS AND METHODS

Medical records of cancer patients who received IORT as a part of their multidisciplinary treatment at King Faisal Specialized Hospital and Research center (KFSH&RC), Riyadh, Saudi Arabia, from January 2013 until December 2017 were retrospectively reviewed.

RESULTS

A total of 188 patients with 210 IORT applications were analyzed. Twenty-two patients had two applications at the same time. One hundred sixteen patients were males. Median age at time of diagnosis was 49.5 years (19-77). One hundred thirty-four patients had primary, while 54 cases had recurrent disease. Gastroesophageal cancer and soft tissue sarcoma were the most frequent diagnosis in 49 patients followed by colorectal cancer in 35 patients. Major surgeries with curative intent done in 183 patients (97.3%). Hyperthermic intraperitoneal chemotherapy (HIPEC) was performed in 118 (62.8%) patients. The 30-day postoperative mortality rate was 3.2%. Fifty-four (28.7%) patients develop grades III-IV complications according to Clavien-Dindo grading system.

CONCLUSION

The data presented discusses using of IORT treatment for different malignant tumors as a part of multimodality treatment. IORT seems safe and feasible; however, a longer follow-up period is needed for proper evaluation and to define the role of IORT in a tailored multimodality approach.

Intraoperative Radiation Therapy for Gastrointestinal Malignancies

Despite improvements in definitive therapy, many patients with gastrointestinal malignancies experience local recurrences or have unresectable disease making subsequent management often challenging and morbid. Although higher doses of radiation may offer improved local control, the ability for dose escalation of external beam radiation therapy is often limited by adjacent radiosensitive structures. Intraoperative radiation therapy allows for additional radiotherapy to be delivered directly to the tumor or areas at highest risk for local recurrence while minimizing toxicity to adjacent structures, offering potentially improved outcomes for patients with unresectable disease or those with a high risk of local recurrence.

Intra-operative Radiation Therapy for Colorectal or Anal Cancer at Risk for Margin-Positive Resection: Initial Results of a Single-Institution Registry

PURPOSE

Pelvic recurrence of rectal or anal cancers is associated with considerable morbidity and mortality. We report our initial experience with an aggressive intra-operative radiotherapy (IORT) program.

METHODS

Patients with locally advanced or recurrent rectal or anal cancers considered to have a high likelihood of R1 or R2 resection after multi-disciplinary review underwent surgical excision and IORT using a high-dose-rate afterloader (Ir-192) and HAM applicator. Endpoints included local or distant recurrence, and acute and late toxicity graded using the American College of Surgeons (ACS) NSQIP and the LENT-SOMA scale.

RESULTS

Twenty-one patients, largely with prior history of both pelvic external beam radiotherapy (EBRT, median 50.4 Gy) and surgical resection, underwent excision with IORT (median dose 12.5 Gy, range 10-15). Median follow-up was 20 months. Twelve (57%) patients had failure at the IORT site. Freedom from failure (FFF) within the IORT field was associated with resection status (FFF at 1 year 75% for R0 vs 15% for R1/2, p = 0.0065) but not re-irradiation EBRT or IORT dose (p > 0.05). Twelve, 5, and 13 patients experienced local, regional, and distant failure, respectively; 3 (14%) patients were disease-free at last follow-up. The most frequent acute toxicity was sepsis/abscess (24%). One patient (5%) required a ureteral stent; no patients developed neuropathy attributable to IORT.

CONCLUSIONS

In patients treated with excision and IORT for locally recurrent cancer, R0 resection is a critical determinant of local control. For patients with R1/2 resection, poor disease-free outcomes warrant consideration of a different treatment strategy.

Practice-oriented solutions integrating intraoperative electron irradiation and personalized proton therapy for recurrent or unresectable cancers: Proof of concept and potential for dual FLASH effect

Background

Oligo-recurrent disease has a consolidated evidence of long-term surviving patients due to the use of intense local cancer therapy. The latter combines real-time surgical exploration/resection with high-energy electron beam single dose of irradiation. This results in a very precise radiation dose deposit, which is an essential element of contemporary multidisciplinary individualized oncology.

Methods

Patient candidates to proton therapy were evaluated in Multidisciplinary Tumor Board to consider improved treatment options based on the institutional resources and expertise. Proton therapy was delivered by a synchrotron-based pencil beam scanning technology with energy levels from 70.2 to 228.7 MeV, whereas intraoperative electrons were generated in a miniaturized linear accelerator with dose rates ranging from 22 to 36 Gy/min (at Dmax) and energies from 6 to 12 MeV.

Results

In a period of 24 months, 327 patients were treated with proton therapy: 218 were adults, 97 had recurrent cancer, and 54 required re-irradiation. The specific radiation modalities selected in five cases included an integral strategy to optimize the local disease management by the combination of surgery, intraoperative electron boost, and external pencil beam proton therapy as components of the radiotherapy management. Recurrent cancer was present in four cases (cervix, sarcoma, melanoma, and rectum), and one patient had a primary unresectable locally advanced pancreatic adenocarcinoma. In re-irradiated patients (cervix and rectum), a tentative radical total dose was achieved by integrating beams of electrons (ranging from 10- to 20-Gy single dose) and protons (30 to 54-Gy Relative Biological Effectiveness (RBE), in 10-25 fractions).

Conclusions

Individual case solution strategies combining intraoperative electron radiation therapy and proton therapy for patients with oligo-recurrent or unresectable localized cancer are feasible. The potential of this combination can be clinically explored with electron and proton FLASH beams.

Re-resection of Microscopically Positive Margins Found on Intraoperative Frozen Section Analysis Does Not Result in a Survival Benefit in Patients Undergoing Surgery and Intraoperative Radiation Therapy for Locally Recurrent Rectal Cancer

BACKGROUND

Intraoperative frozen-section analysis provides real-time margin resection status that can guide intraoperative decisions made by the surgeon and radiation oncologist. For patients with locally recurrent rectal cancer undergoing surgery and intraoperative radiation therapy, intraoperative re-resection of positive margins to achieve negative margins is common practice.

OBJECTIVE

This study aimed to assess whether re-resection of positive margins found on intraoperative frozen-section analysis improves oncologic outcomes.

DESIGN

This is a retrospective cohort study.

SETTINGS

This study was an analysis of a prospectively maintained multicenter database.

PATIENTS

All patients who underwent surgical resection of locally recurrent rectal cancer with intraoperative radiation therapy between 2000 and 2015 were included and followed for 5 years. Three groups were compared: initial R0 resection, initial R1 converted to R0 after re-resection, and initial R1 that remained R1 after re-resection. Grossly positive margin resections (R2) were excluded.

MAIN OUTCOME MEASURES

The primary outcome measures were 5-year overall survival, recurrence-free survival, and local re-recurrence.

RESULTS

A total of 267 patients were analyzed (initial R0 resection, n = 94; initial R1 converted to R0 after re-resection, n = 95; initial R1 that remained R1 after re-resection, n = 78). Overall survival was 4.4 years for initial R0 resection, 2.7 years for initial R1 converted to R0 after re-resection, and 2.9 years for initial R1 that remained R1 after re-resection ( p = 0.01). Recurrence-free survival was 3.0 years for initial R0 resection and 1.8 years for both initial R1 converted to R0 after re-resection and initial R1 that remained R1 after re-resection ( p ≤ 0.01). Overall survival did not differ for patients with R1 and re-resection R1 or R0 ( p = 0.62). Recurrence-free survival and freedom from local re-recurrence did not differ between groups.

LIMITATIONS

This study was limited by the heterogeneous patient population restricted to those receiving intraoperative radiation therapy.

CONCLUSIONS

Re-resection of microscopically positive margins to obtain R0 status does not appear to provide a significant survival advantage or prevent local re-recurrence in patients undergoing surgery and intraoperative radiation therapy for locally recurrent rectal cancer. See Video Abstract at http://links.lww.com/DCR/B886 .

LA RERESECCIN DE LOS MRGENES MICROSCPICAMENTE POSITIVOS ENCONTRADOS DE MANERA INTRAOPERATORIA MEDIANTE LA TCNICA DE CRIOSECCIN, NO DA COMO RESULTADO UN BENEFICIO DE SUPERVIVENCIA EN PACIENTES SOMETIDOS A CIRUGA Y RADIOTERAPIA INTRAOPERATORIA PARA EL CNCER RECTAL LOCALMENTE RECIDIVANTE

ANTECEDENTES:El análisis de la ténica de criosección para los margenes positivos encontrados de manera intraoperatoria proporciona el estado de la resección del margen en tiempo real que puede guiar las decisiones intraoperatorias tomadas por el cirujano y el oncólogo radioterapeuta. Para los pacientes con cáncer de recto localmente recurrente que se someten a cirugía y radioterapia intraoperatoria, la re-resección intraoperatoria de los márgenes positivos para lograr márgenes negativos es una práctica común.OBJETIVO:Evaluar si la re-resección de los márgenes positivos encontrados en el análisis de la ténica por criosecciónde manera intraoperatorios mejora los resultados oncológicos.DISEÑO:Estudio de cohorte retrospectivo.AJUSTES:Análisis de una base de datos multicéntrica mantenida de forma prospectiva.POBLACIÓN:Todos los pacientes que se sometieron a resección quirúrgica de cáncer de recto localmente recurrente con radioterapia intraoperatoria entre 2000 y 2015 fueron incluidos y seguidos durante 5 años. Se compararon tres grupos: resección inicial R0, R1 inicial convertido en R0 después de la re-resección y R1 inicial que permaneció como R1 después de la re-resección. Se excluyeron las resecciones de márgenes macroscópicamente positivos (R2).PRINCIPALES MEDIDAS DE RESULTADO:Supervivencia global a cinco años, supervivencia sin recidiva y recidiva local.RESULTADOS:Se analizaron un total de 267 pacientes (resección inicial R0 n = 94, R1 inicial convertido en R0 después de la re-resección n = 95, R1 inicial que permaneció como R1 después de la re-resección n = 78). La supervivencia global fue de 4,4 años para la resección inicial R0, 2,7 años para la R1 inicial convertida en R0 después de la re-resección y 2,9 años para la R1 inicial que permaneció como R1 después de la re-resección ( p = 0,01). La supervivencia libre de recurrencia fue de 3,0 años para la resección inicial R0 y de 1,8 años para el R1 inicial convertido en R0 después de la re-resección y el R1 inicial que permaneció como R1 después de la re-resección ( p ≤ 0,01). La supervivencia global no difirió para los pacientes con R1 y re-resección R1 o R0 ( p = 0,62). La supervivencia libre de recurrencia y la ausencia de recurrencia local no difirieron entre los grupos.LIMITACIONES:Población de pacientes heterogénea, restringida a aquellos que reciben radioterapia intraoperatoria.CONCLUSIONES:La re-resección de los márgenes microscópicamente positivos para obtener el estado R0 no parece proporcionar una ventaja de supervivencia significativa o prevenir la recurrencia local en pacientes sometidos a cirugía y radioterapia intraoperatoria para el cáncer de recto localmente recurrente. Consulte Video Resumen en http://links.lww.com/DCR/B886 . (Traducción-Dr. Daniel Guerra ).

Feasibility and Safety of Intraoperative Radiotherapy with Low Energy X-ray Photon Therapy for Recurrent Gynecological Cancer: A Case Series

Objectives: To evaluate the feasibility and safety of low energy X-ray photon intraoperative radiotherapy (IORT) as an adjuvant therapy for recurrent gynecological cancer.Methods: Medical records of all recurrence gynecological cancer patients who underwent IORT were reviewed. Results: Between January 2018 and December 2021, five women (including cervical cancer (n = 2), endometrial cancer (n = 2), and uterine leiomyosarcoma (n = 1)), who underwent IORT and surgical resection for recurrent gynecologic cancer were reviewed. A median dose of 15.62 Gy (range, 12 to 20 Gy) was used for IORT. Repeated IORT and surgical resection was performed in two women. Three women experienced local recurrence, and three women died during follow-up. The 1-year local control rate was 60%. The 2-year overall survival rate was 30%. There was no Clavien–Dindo classification grade III–V complication. Conclusion: IORT using low energy X-ray photon therapy seems to be feasible and safe as an adjuvant therapy in women who underwent salvage surgery for recurrent gynecologic cancer. However, large-scale prospective studies are needed to confirm our findings and evaluate its efficacy.

Review of incomplete macroscopic resections (R2) in rectal cancer: Treatment, prognosis and future perspectives

Colorectal cancer is one of the most prevalent tumours, but with improved treatment and early detection, its prognosis has greatly improved in recent years. However, when the tumour is locally advanced at diagnosis or if there is local recurrence, it is more difficult to perform a complete tumour resection, and there may be a residual macroscopic tumour. In this paper, we review the literature on residual macroscopic tumour resections, concerning both locally advanced primary tumours and recurrences, evaluating the main problems encountered, the treatments applied, the prognosis and future perspectives in this field.

The role of intraoperative radiotherapy in advanced rectal cancer: a meta-analysis

AIM

Patients with locally advanced and locally recurrent rectal cancer (LARC/LRRC) experience higher rates of local recurrence (LR) and poorer overall survival than patients with primary rectal cancer restricted to the mesorectum despite improved neoadjuvant treatment regimens and radical surgical procedures. Intraoperative radiotherapy (IORT) has been suggested as an adjunctive tool in the surgical management of these challenging cases. However, clear evidence regarding the oncological benefit of IORT is sparse. The aim of this review was to update this evidence in the era of standardized neoadjuvant radiotherapy administration.

METHOD

A systematic review of patients who received IORT as part of multimodal treatment for advanced rectal cancer from 2000 to 2020 and an analysis of IORT and surgery/external beam radiotherapy (EBRT) groups was performed. The primary endpoint was the rate of LR between the two groups.

RESULTS

Seven papers met the predefined criteria. LR was reduced by the addition of IORT when compared with the surgery/EBRT alone group (14.7% vs. 21.4%; OR 0.55, 95% CI 0.27-1.14; p = 0.11). There was no increase in reported genitourinary morbidity, wound issues, pelvic collections or anastomotic leak in those patients who received IORT. Notably, there was no survival difference between the two groups.

CONCLUSION

The addition of IORT to current treatment strategies in the management of patients with LARC/LRRC is associated with a lower rate of locoregional recurrence without increased morbidity. However, this marks a highly selective group of patients, with heterogeneity regarding indications, prior neoadjuvant treatments and/or IORT dosing.

Clinical selection strategy for and evaluation of intra-operative brachytherapy in patients with locally advanced and recurrent rectal cancer

BACKGROUND AND PURPOSE

A radical resection of locally advanced rectal cancer (LARC) or recurrent rectal cancer (RRC) can be challenging. In case of increased risk of an R1 resection, intra-operative brachytherapy (IOBT) can be applied. We evaluated the clinical selection strategy for IOBT.

MATERIALS AND METHODS

Between February 2007 and May 2018, 132 LARC/RRC patients who were scheduled for surgery with IOBT standby, were evaluated. By intra-operative inspection of the resection margin and MR imaging, it was determined whether a resection was presumed to be radical. Frozen sections were taken on indication. In case of a suspected R1 resection, IOBT (1 × 10 Gy) was applied. Histopathologic evaluation, treatment and toxicity data were collected from medical records.

RESULTS

Tumour was resected in 122 patients. IOBT was given in 42 patients of whom 54.8% (n = 23) had a histopathologically proven R1 resection. Of the 76 IOBT-omitted R0 resected patients, 17.1% (n = 13) had a histopathologically proven R1 resection. In 4 IOBT-omitted patients, a clinical R1/2 resection was seen. In total, correct clinical judgement occurred in 72.6% (n = 88) of patients. In LARC, 58.3% (n = 14) of patients were overtreated (R0, with IOBT) and 10.9% (n = 5) were undertreated (R1, without IOBT). In RRC, 26.5% (n = 9) of patients were undertreated.

CONCLUSION

In total, correct clinical judgement occurred in 72.6% (n = 88). However, in 26.5% (n = 9) RRC patients, IOBT was unjustifiedly omitted. IOBT is accompanied by comparable and acceptable toxicity. Therefore, we recommend IOBT to all RRC patients at risk of an R1 resection as their salvage treatment.

Assessing the Effect of Radiotherapy in Addition to Surgery in Colon Adenocarcinomas: a Systematic Review and Meta-analysis of Contemporary Evidence

PURPOSE

This study aims to review the contemporary evidence investigating radiotherapy (RT) in addition to surgery for colon adenocarcinomas.

METHODS

We searched the following databases: PubMed, Science Direct, Scopus, ASCOpubs, the Cochrane Library, and Google Scholar. Studies (since January 2005) comparing outcomes of high-risk colon adenocarcinomas who underwent RT in addition to surgery versus no RT were eligible. Pooling of outcomes from published results or from analysis of survival curves was done. Subgroup analysis was conducted to determine if the efficacy of RT varies with RT timing.

RESULTS

Eight studies were included (five retrospective cohorts, three population-based studies). Pooled analysis from retrospective cohorts showed a reduction in 5-year LR (OR 0.41; 95% CI 0.21-0.79; p = 0.007) in the RT group. A benefit in 3-year (OR 1.81; 95% CI 1.15-2.87; p = 0.01) and 5-year (OR 2.10; 95% CI 1.21-3.63; p = 0.008) DFS and in 3-year (OR 2.55; 95% CI 1.43-4.54; p = 0.001) and 5-year (OR 2.00; 95% CI 1.17-3.41; p = 0.01) OS was seen in the RT group. The OS benefit was demonstrated in the subgroup analysis of neoadjuvant RT, but not with adjuvant RT. The improvement in OS with neoadjuvant RT was supported by a population-based study from NCDB, while results from two population-based studies investigating adjuvant RT were conflicting.

CONCLUSION

Taking into account the limitations of the studies, our review of evidence suggests a possible role of RT in improving oncologic outcomes of select colon adenocarcinomas. Prospective studies are needed to definitively assess the value of RT for colon cancer.

Outcome of Sacropelvic Resection and Reconstruction Based on a Novel Classification System

BACKGROUND

Sacral tumor resections require a multidisciplinary approach to achieve a cure and a functional outcome. Currently, there is no accepted classification system that provides a means to communicate among the multidisciplinary teams in terms of approach, osseous resection, reconstruction, and acceptable functional outcome. The purpose of this study was to report the outcome of sacral tumor resection based on our classification system.

METHODS

In this study, 196 patients (71 female and 125 male) undergoing an oncologic en bloc sacrectomy were reviewed. The mean age (and standard deviation) was 49 ± 16 years, and the mean body mass index was 27.2 ± 6.4 kg/m. The resections included 130 sarcomas (66%). The mean follow-up was 7 ± 5 years.

RESULTS

Resections included total sacrectomy (Type 1A: 20 patients [10%]) requiring reconstruction, subtotal sacrectomy (Type 1B: 5 patients [3%]) requiring reconstruction, subtotal sacrectomy (Type 1C: 104 patients [53%]) not requiring reconstruction, hemisacrectomy (Type 2: 29 patients [15%]), external hemipelvectomy and hemisacrectomy (Type 3: 32 patients [16%]), total sacrectomy and external hemipelvectomy (Type 4: 5 patients [3%]), and hemicorporectomy (Type 5: 1 patient [1%]). The disease-specific survival was 66% at 5 years and 52% at 10 years. Based on the classification, the 5-year disease-specific survival was 34% for Type 1A, 100% for Type 1B, 71% for Type 1C, 65% for Type 2, 57% for Type 3, 100% for Type 4, and 100% for Type 5 (p < 0.001). Tumor recurrence occurred in 67 patients, including isolated local recurrence (14 patients), isolated metastatic disease (31 patients), and combined local and metastatic disease (22 patients). At 5 years, the local recurrence-free survival was 77% and the metastasis-free survival was 68%. Complications occurred in 153 patients (78%), most commonly wound complications (95 patients [48%]). Following the procedure, 154 patients (79%) were ambulatory, and the mean Musculoskeletal Tumor Society (MSTS93) score was 60% ± 23%.

CONCLUSIONS

Although resections of sacral malignancies are associated with complications, they can be curative in a majority of patients, with a majority of patients ambulatory with an acceptable functional outcome considering the extent of the resection. At our institution, this classification allows for communication between surgical teams and implies a surgical approach, staging, reconstruction, and potential functional outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The efficacy and dosimetry analysis of CT-guided 125I seed implantation assisted with 3D-printing non-co-planar template in locally recurrent rectal cancer

Background

Locally recurrent rectal cancer (LRRC) after surgery or external beam radiotherapy (EBRT) is a serious challenge for which no standard treatment is defined. In the present study, we investigated the feasibility of computed tomography (CT)-guided radioactive ¹²⁵I seed (RIS) implantation assisted with three-dimensional printing non-coplanar template (3D-PNCT) in LRRC patients who previously received surgery or EBRT.

Methods

Sixty-six patients with LRRC treated by CT-guided RIS implantation in our institute from December 2015 to May 2019 were included. The treatment procedure included: preoperative CT localization, planning design, the printing of 3D individualized template, CT-guided RIS implantation assisted with 3D-PNCT, and postoperative dose evaluation. Therapeutic outcomes including local control (LC) and overall survival (OS) were retrospectively evaluated, as well as side effects.

Results

All the patients had previously received surgery or EBRT. The median follow-up time was 12.2 (range, 2.5–35.9) months. The median radioactive activity of a single RIS was 0.6 (range, 0.43–0.72) mCi. The median number of RIS was 60, ranging from 10 to 175. The dosimetric parameters included D90 (140.7 ± 33.1) Gy, D100 (90.3 ± 138.6) Gy, and V100 (91.0 ± 13.3) %. Pain relief was achieved in 85.1% (40/47) of patients. Besides, 9.1% (6/66) of patients had severe side effects (≥grade 3), including perianal skin ulcer in 1 case, fistula, radiation proctitis, and intestinal obstruction each in two cases. Median OS time was 14.7 (95% confidence interval (CI): 13.0–16.3) months, and median LC time was 12.2 (95% CI: 9.1–15.2) months. Univariate analysis revealed that when D90 > 130 Gy or D100 > 55 Gy or V100 > 90%, the LC time was remarkably prolonged. However, none of the parameters significantly affected OS.

Conclusions

CT-guided RIS implantation assisted with 3D-PNCT is an effective and safe salvage treatment strategy for patients with LRRC after EBRT or surgery. D90, D100, and V100 can be used as prognostic predictors.

Trial registration

NCT03890926.

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.

Intraoperative Strahlentherapie – Indikationen und Optionen in der Viszeralchirurgie

Hintergrund

Die intraoperative Strahlentherapie (IORT) ermöglicht durch die chirurgische Exposition des Tumors und des Tumorbetts eine hohe Präzision, welche eine hohe Strahlendosis im Bereich des Tumors zulässt und gleichzeitig gesundes Gewebe als den dosislimitierenden Faktor vor Strahlung schützt. Aus diesem Grund bietet die IORT besonders dann einen Vorteil, wenn die lokale Tumorkontrolle das Langzeitüberleben entscheidend beeinflusst und Funktionserhalt ermöglicht.

Ziel der Arbeit

Die in dieser Übersichtsarbeit aufgearbeiteten Erkenntnisse aus der Literaturrecherche erlauben einen evidenzbasierten Umgang hinsichtlich Indikationen und Therapieoptionen der IORT für intraabdominelle Tumoren.

Ergebnisse und Schlussfolgerung

Die Effektivität der IORT kann anhand der vorhandenen Evidenzlage nicht abschließend beurteilt werden, jedoch ist die IORT als Ergänzung der multimodalen Therapie bei (Rezidiv‑)Rektumkarzinomen und Sarkomen aktiv im klinischen Alltag etabliert. Magen- und Pankreaskarzinome stellen weitere Indikationen dar; ergänzende Studien sind jedoch notwendig, um die Rolle der IORT hier klar zu definieren. Ein wesentlicher Faktor, damit für Patienten mit primärem Karzinom und insbesondere für Patienten mit lokalem Rezidiv verbesserte lokale Rezidiv- und Überlebensraten erreicht werden können, scheint die Patientenselektion zu sein.

Improving bleeding detector features for electron intraoperative radiotherapy

PURPOSE

The aim of this work is to improve the potential bleeding detection during intraoperative radiotherapy with linac polymethyl methacrylate applicators (PMMA), based on one previously developed. The improvements carried out have been focused on: i) minimizing the impact of the detector on the visual through the plastic applicators and ii) avoiding the asymmetry in the detection capability when the applicator is tilted.

METHODS

Simulations have been made to select the geometry that provides a reduced visual impact on the applicator as well as allowing an independent response with the tilting angle of the applicator. A low-noise circuit for signal conditioning has been developed. Measurements have been made on three setups: 10 cm, 7 cm and 4 cm applicator diameters, 0° and 45° tilted.

RESULTS

The detector has a visibility through the applicator greater than 50%. Due to the geometry, optimal detection is ensured regardless of its orientation when the applicator is tilted. It is possible to detect the presence of fluid well below the typical perturbing fluid depth established by the clinic (1-1.5 cm).

CONCLUSIONS

The detector can distinguish the presence of around 0.5 cm of fluid depth while showing a high visual field through the PMMA applicators and providing a measure that does not depend on the detector orientation when the applicator is tilted. The prototype is ready for its industrialization by embedding it into the applicator for clinical use. The detector would have a significant impact on both the quality assurance and the outcome of the treatment.

A Review on the Special Radiotherapy Techniques of Colorectal Cancer

Colorectal cancer is one of the commonest cancers worldwide. Radiotherapy has been established as an indispensable component of treatment. Although conventional radiotherapy provides good local control, radiotherapy treatment side-effects, local recurrence and distant metastasis remain to be the concerns. With the recent technological advancements, various special radiotherapy treatment options have been offered. This review article discusses the recently-developed special radiotherapy treatment modalities for various conditions of colorectal cancer ranging from early stage, locally advanced stage, recurrent, and metastatic diseases. The discussion focuses on the areas of feasibility, local control, and survival benefits of the treatment modalities. This review also provides accounts of the future direction in radiotherapy of colorectal cancer with emphasis on the coming era of personalized radiotherapy.

Intraoperative radiation therapy for the treatment of recurrent retroperitoneal and pelvic tumors: a single-institution analysis

Background

Patients with recurrent retroperitoneal and pelvic region tumors often require multimodal therapies. Intraoperative radiation therapy (IORT) can deliver high-dose radiation to tumor beds, even if first-line external beam radiation therapy (EBRT) was administered. We evaluated local control (LC) and survival in patients receiving IORT for recurrent tumors.

Methods

We retrospectively analyzed 41 patients with isolated pelvic or retroperitoneal recurrences of colorectal, gynecological, or retroperitoneal primary tumors. Following salvage surgery, all patients underwent tumor bed IORT via electron beam or high dose rate brachytherapy. Isolated IORT (median dose: 15 Gy) was administered to patients who had received first-line EBRT; other patients received IORT (median dose 12 Gy) plus EBRT. Local (LF), regional (RF), and distant failures (DF) were evaluated, and the Kaplan–Meier method and log-rank test were used to evaluate and compare overall survival (OS) from the date of IORT.

Results

Forty-one patients underwent 44 treatments, including 27 (61.3%) isolated IORT and 17 (38.7%) IORT and EBRT combination regimens. The median follow-up was 8.1 years (range: 4.4–11.7 years), and the 2, 5, and 8 year overall LC rates were 87.9, 64.0, and 49.8%, respectively. Regarding resection status, the respective 2, 5, and 8 year LC rates were 90, 76, and 76% for R0 resection and 75, 25, and 0% for R1 resection (p < 0.001). The 2, 5, and 8 year OS rates were 68, 43, and 26%, respectively. OS was better among patients with LC (p < 0.001). Twenty-four patients (58.5%) experienced a DF, and the 5 year OS rates for the patients with and without DF were 36 and 52%, respectively (p = 0.04).

In a multivariate analysis, LF (p = 0,012) and recurrent retroperitoneal sarcoma (p = 0,014) were identified as significant predictors of worse OS. Thirteen patients (31%) developed clinically treatable complications related to IORT.

Conclusions

Many patients achieve long-term OS and LC without significant morbidity after salvage surgery and IORT, especially in case of clear margins.

Surgical Resection with Neoadjuvant Chemotherapy for Locoregionally Recurrent Appendiceal Cancer Invading the External Iliac Vessels

Recent advancements in multimodal therapy can provide oncologic benefits for patients with recurrent colorectal cancer. This report presents a case of locoregionally recurrent appendiceal cancer treated with neoadjuvant chemotherapy followed by surgical resection with vascular reconstruction. A 68-year-old Japanese woman was diagnosed with appendiceal cancer and underwent ileocecal resection. The pathological evaluation revealed KRAS-mutant adenocarcinoma with the final stage of T4bN1M0. She received oral fluorouracil-based adjuvant chemotherapy. One year later, she was found to have peritoneal dissemination in the pelvic cavity and vaginal metastasis. She received an oxaliplatin-based chemotherapy followed by surgical resection. One year after the second surgery, she developed a locoregional recurrence involving the right external iliac vessels and small intestine. She received an irinotecan-based regimen with bevacizumab as neoadjuvant chemotherapy, followed by surgical resection. At first, a femoro-femoral bypass was made to secure the blood supply to the right lower extremities. Subsequently, an en bloc resection including the recurrent tumor and the external iliac vessels was completed. Surgical resection for recurrent colorectal cancer is often technically challenging because of the tumor location and invasion to adjacent organs. In this case, a surgical approach with persistent chemotherapy achieved oncologic resection of locoregionally recurrent appendiceal cancer.

Treatment of primary rectal adenocarcinoma after prior pelvic radiation: The role of hyperfractionated accelerated reirradiation

Purpose

Previous studies have reported that hyperfractionated accelerated reirradiation can be used as part of multimodality treatment of locally recurrent rectal cancer with acceptable toxicity and promising outcomes. The purpose of this study was to evaluate the outcomes and toxicity of hyperfractionated accelerated reirradiation for patients with primary rectal adenocarcinoma and a history of prior pelvic radiation for other primary malignancies.

Methods and materials

We identified 10 patients with a prior history of pelvic radiation for other primary malignancies who were treated with hyperfractionated accelerated reirradiation for primary rectal adenocarcinoma. Radiation therapy was administered with 1.5 Gy twice daily fractions to a total dose of 39 Gy to 45Gy.

Results

The median follow-up time was 3.2 years (range, 0.6-9.0 years). Seven of 10 patients received surgery after reirradiation. The 3-year freedom-from-local-progression rate was 62% for all patients and 80% for patients who underwent surgery. The 3-year overall survival rate was 100%, with 3 deaths occurring at 4.7, 6.5, and 9.0 years after reirradiation. One patient had an acute Grade 3 toxicity of diarrhea, and 1 patient experienced a late Grade 3 toxicity of sacral insufficiency fracture.

Conclusions

Hyperfractionated accelerated reirradiation was well tolerated with promising rates of freedom from local progression and overall survival in patients with primary rectal cancer with a history of prior pelvic radiation therapy. This approach, along with concurrent chemotherapy and surgery, appears to be a viable treatment strategy for this patient population.

Development of a pelvic exenteration service at a tertiary referral centre

BACKGROUND

Over one-third of primary rectal cancers are locally advanced at diagnosis, and local recurrence of rectal cancer occurs at a rate of 3-10% following primary curative resection. Extended resectional surgery, including pelvic exenteration, is the only proven therapy with curative potential in the treatment of these cancers along with many other pelvic malignancies. A microscopically clear resection margin (R0 resection) is the predominant prognostic factor affecting overall and disease-free survival. The extent and complexity of surgery required to achieve an R0 resection is associated with significant risk of morbidity and mortality. The aim of this paper is to show that pelvic exenterations can be performed with acceptable oncological and safe perioperative results in an appropriately resourced specialist centre.

METHODS

Data was collected retrospectively for 61 consecutive patients treated between June 2012 and February 2017. This included patient demographics, tumour characteristics, operative, clinical and histological data, length of hospital stay, morbidity and mortality data.

RESULTS

A total of 61 patients underwent surgery. Median age was 57 years (range 27-78 years). Median length of stay was 41 days (range 6-288 days). Median operative time was 624 min (range 239-1035 min); 30-day mortality was 3.3% (n = 2). Resection rates were 91.5% - R0, 6.8% - R1 and 1.7% - R2 resections. Histologically, 86.9% - adenocarcinomas, 3.3% - squamous cell carcinomas and 9.8% - represented by leiomyosarcoma, melanoma, myxoid chondrosarcoma, non-neoplastic processes and undifferentiated carcinoma.

CONCLUSION

Our experience confirms that radical resectional pelvic surgery can be safely performed with acceptable results during the establishment phase of a dedicated tertiary service.

Commissioning, clinical implementation, and performance of the Mobetron 2000 for intraoperative radiation therapy

The Mobetron is a mobile electron accelerator designed to deliver therapeutic radiation dose intraoperatively while diseased tissue is exposed. Experience with the Mobetron 1000 has been reported extensively. However, since the time of those publications a new model, the Mobetron 2000, has become commercially available. Experience commissioning this new model and 3 years of data from historical use are reported here. Descriptions of differences between the models are emphasized, both in physical form and in dosimetric characteristics. Results from commissioning measurements including output factors, air gap factors, percent depth doses (PDDs), and 2D dose profiles are reported. Output factors are found to have changed considerably in the new model, with factors as high as 1.7 being measured. An example lookup table of appropriate accessory/energy combinations for a given target dimension is presented, and the method used to generate it described. Results from 3 years of daily QA measurements are outlined. Finally, practical considerations garnered from 3 years of use are presented.

Technical Note: Mobile accelerator guidance using an optical tracker during docking in IOERT procedures

PURPOSE

Intraoperative electron radiation therapy (IOERT) involves the delivery of a high radiation dose during tumor resection in a shorter time than other radiation techniques, thus improving local control of tumors. However, a linear accelerator device is needed to produce the beam safely. Mobile linear accelerators have been designed as dedicated units that can be moved into the operating room and deliver radiation in situ. Correct and safe dose delivery is a key concern when using mobile accelerators. The applicator is commonly fixed to the patient's bed to ensure that the dose is delivered to the prescribed location, and the mobile accelerator is moved to dock the applicator to the radiation beam output (gantry). In a typical clinical set-up, this task is time-consuming because of safety requirements and the limited degree of freedom of the gantry. The objective of this study was to present a navigation solution based on optical tracking for guidance of docking to improve safety and reduce procedure time.

METHOD

We used an optical tracker attached to the mobile linear accelerator to track the prescribed localization of the radiation collimator inside the operating room. Using this information, the integrated navigation system developed computes the movements that the mobile linear accelerator needs to perform to align the applicator and the radiation gantry and warns the physician if docking is unrealizable according to the available degrees of freedom of the mobile linear accelerator. Furthermore, we coded a software application that connects all the necessary functioning elements and provides a user interface for the system calibration and the docking guidance.

RESULT

The system could safeguard against the spatial limitations of the operating room, calculate the optimal arrangement of the accelerator and reduce the docking time in computer simulations and experimental setups.

CONCLUSIONS

The system could be used to guide docking with any commercial linear accelerator. We believe that the docking navigator we present is a major contribution to IOERT, where docking is critical when attempting to reduce surgical time, ensure patient safety and guarantee that the treatment administered follows the radiation oncologist's prescription.

Intraoperative radiotherapy: review of techniques and results

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

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

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

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

Standard fractionation external beam radiotherapy with and without intraoperative radiotherapy for locally recurrent rectal cancer: the role of local therapy in patients with a high competing risk of death from distant disease

OBJECTIVE

We sought to evaluate the effectiveness and safety of utilizing radiotherapy (RT) with standard fractionation, with or without intraoperative RT (IORT), to treat locally recurrent rectal cancer (LRRC).

METHODS

Retrospective review of 25 patients with LRRC treated with standard fractionation RT from 2005 to 2011. 15 patients (60%) had prior pelvic RT and 10 (40%) had synchronous metastases. The median equivalent dose in 2-Gy fractions was 30 and 49.6 Gy in patients with and without prior RT, respectively. 23 patients (92%) received concurrent chemotherapy and 16 (64%) underwent surgical resection. Eight patients (33.3%, four with and four without prior RT) received IORT. A competing risks model was developed to estimate the cumulative incidence of local failure with death treated as a competing event.

RESULTS

Median follow-up was 36.9 months after the date of local recurrence. 3-year rates of overall survival (OS), local control (LC) and death with LC were 51.6%, 73.3% and 69.2%, respectively. On multivariable analysis, surgical resection was significantly predictive of improved OS (p < 0.05). If surgical resection were removed from the multivariable model, given the collinearity between IORT delivery and surgical resection, then IORT also became a significant predictor of OS (p < 0.05). Systemic disease at the time of local recurrence was not associated with either LC or OS. No patient had grade ≥3 acute or late toxicity.

CONCLUSION

RT with standard fractionation is safe and effective in the treatment of patients with LRRC, even in patients with significant risk of systemic disease and/or history of prior RT. Advances in knowledge: The utility of RT with standard fractionation, generally with chemotherapy, in the treatment of LRRC is demonstrated. In this high-risk cohort of patients with a 40% incidence of synchronous metastatic disease, surgical resection of the recurrence was the major predictor of OS, though a benefit to IORT was also suggested. No patients had grade ≥3 acute or late toxicity, though 40% had undergone prior RT, underscoring the tolerability of standard fractionation RT in this setting.

Intraoperative radiation therapy (IORT) in soft-tissue sarcoma

Soft-tissue sarcoma (STS) represent a rare tumor entity, accounting for less than 1% of adult malignancies. The cornerstone of curative intent treatment is surgery with free margins, although the extent of the surgical approach has been subject to change in the last decades. Multimodal approaches usually including radiation therapy have replaced extensive surgical procedures in order to preserve functionality while maintaining adequate local control. However, the possibility to apply adequate radiation doses by external beam radiation therapy (EBRT) can be limited in some situation especially in case of directly adjacent organs at risk with low radiation tolerance. Application of at least a part of the total dose via intraoperative radiation therapy (IORT) with a single fraction during the surgical procedure may overcome those limitations, because radiosensitive structures can be moved out of the radiation field resulting in reduced toxicity while the enhanced biological effectivity of the high single dose improves local control. The current review summarizes rationale, techniques, oncological and functional outcomes including possible pitfalls and associated toxicities based on the published literature for IORT focusing on extremity and retroperitoneal STS. In extremity STS, combination of limb-sparing surgery, IORT and pre- or postoperative EBRT with moderate doses consistently achieved excellent local control rates at least comparable to approaches using EBRT alone but usually including patient cohorts with higher proportions of unfavourable prognostic factors. Further on, IORT containing approaches resulted in very high limb preservation rates and good functional outcome, probably related to the smaller high dose volume. In retroperitoneal STS, the combination of preoperative EBRT, surgery and IORT consistently achieved high local control rates which seem superior to surgery alone or surgery with EBRT at least with regard to local control and in some reports even to overall survival. Further on, preoperative EBRT in combination with IORT seems to be superior to the opposite combination with regard to local control and toxicity. No major differences in wound healing disturbances or postoperative complication rates can be observed with IORT compared to non-IORT containing approaches. Neuropathy of major nerves remains a dose limiting toxicity requiring dose restrictions or exclusion from target volume. Gastrointestinal structures and ureters should be excluded from the IORT area whenever possible and the IORT volume should be restricted to the available minimum. Nevertheless, IORT represents an ideal boosting method if combined with EBRT and properly executed by experiences users which should be further evaluated preferably in prospective randomized trials.

Intraoperative radiation therapy for colon and rectal cancers: a clinical review

Although there have been significant advances in the adjuvant therapy of colorectal cancer, results for patients have historically been poor when complete resection is unlikely or not possible. Similarly, locally recurrent colorectal cancer patients often experience significant tumor related morbidity and disease control and long term survival have historically been poor with standard therapies. Intraoperative radiation therapy (IORT) has been proposed as a possible tool for dose escalation in patients with locally advanced colorectal cancer.

For patients with locally advanced primary or recurrent colon cancer, the absence of prospective controlled trials limits the ability to draw definitive conclusions in completely resected patients. In subtotally resected patients, the available evidence is consistent with marked improvements in disease control and survival compared to historical controls. For patients with locally advanced primary or recurrent rectal cancer, a relatively large body of evidence suggests improved disease control and survival, especially in subtotally resected patients, with the addition of IORT to moderate dose external beam radiation (EBRT) and chemotherapy. The most important prognostic factor in nearly all series is the completeness of surgical resection. Many previously irradiated patients may be carefully re-treated with radiation and IORT in addition to chemotherapy resulting in long term survival in more than 25% of patients. Peripheral nerve is dose limiting for IORT and patients receiving 15 Gy or more are at higher risk.

IORT is a useful tool when dose escalation beyond EBRT tolerance limits is required for acceptable local control in patients with locally advanced primary or recurrent colorectal cancer. Previously irradiated patients should not be excluded from treatment consideration.

Hyperfractionated accelerated reirradiation for rectal cancer: An analysis of outcomes and toxicity

BACKGROUND AND PURPOSE

To evaluate outcomes and toxicity in patients treated with hyperfractionated pelvic reirradiation for recurrent rectal cancer.

MATERIALS AND METHODS

102 patients with recurrent rectal adenocarcinoma were treated with pelvic reirradiation with a hyperfractionated accelerated approach, consisting of 1.5Gy twice daily fractions to a total dose of 30-45Gy (median 39Gy), with the most common total dose 39Gy (n=90, 88%). The median dose of prior pelvic radiation therapy (RT) was 50.4Gy (range: 25-63Gy).

RESULTS

The median follow-up was 40months for living patients (range, 3-150months). The 3-year freedom from local progression (FFLP) rate was 40% and the 3-year overall survival (OS) rate was 39%. Treatment with surgery was significantly associated with improved FFLP and OS, with 3-year FFLP rate of 49% vs. 30% (P=0.013), and 3-year OS rate of 62% vs. 20% (P<0.0001), compared to those without surgery. The actuarial 3-year rate of grade 3-4 late toxicity was 34%; patients who underwent surgery had a significantly higher rate of grade 3-4 late toxicity compared to those without surgery (54% vs. 16%, P=0.001).

CONCLUSIONS

This large, retrospective, single-institution study shows that hyperfractionated accelerated reirradiation was well tolerated. The rate of FFLP was promising, given that the study comprised heavily pre-treated patients with recurrences. Rates of FFLP and OS were particularly impressive in patients who underwent both reirradiation and surgery.

Influence of intraoperative radiation therapy on locally advanced and recurrent colorectal tumors: A 16-year experience

BACKGROUND

Intraoperative radiation therapy (IORT) has been proposed as a tool to improve local control in patients with locally advanced primary or recurrent colorectal cancer.

METHODS

A retrospective review (1999-2015) of all patients undergoing IORT for locally advanced or recurrent colorectal cancer at a single academic center was performed. Patient demographics, oncologic staging, short-term and long-term outcomes were reviewed.

RESULTS

There were 77 patients (mean age 63 ± 11 years) identified, of whom 19 had colon cancer, 57 had rectal cancer, and 2 had appendiceal cancers. R0 resection was performed in 53 patients (69%), R1 in 19 (25%) and R2 in 5 (6%). Ten (13%) patients had a local recurrence at 18 ± 14 months and 34 (44%) had a distant recurrence at 18 ± 18 months. Mean survival was 47 ± 41 months.

CONCLUSION

IORT resulted in low local failure rates and should be considered for patients with locally advanced or recurrent colorectal cancers.

Results of a pooled analysis of IOERT containing multimodality treatment for locally recurrent rectal cancer: Results of 565 patients of two major treatment centres

OBJECTIVE

Aim of this study is analysing the pooled results of Intra-Operative Electron beam Radiotherapy (IOERT) containing multimodality treatment of locally recurrent rectal cancer (LRRC) of two major treatment centres.

METHODS AND MATERIALS

Five hundred sixty five patients with LRRC who underwent multimodality-treatment up to 2010 were studied. The preferred treatment was preoperative chemo-radiotherapy, surgery and IOERT. In uni- and multivariate analyses risk factors for local re-recurrence, distant metastasis free survival, relapse free survival, cancer-specific survival and overall survival were studied.

RESULTS

Two hundred fifty one patients (44%) underwent a radical (R0) resection. In patients who had no preoperative treatment the R0 resection rate was 26%, and this was 43% and 50% for patients who respectively received preoperative re-(chemo)-irradiation or full-course radiotherapy (p < 0.0001). After uni- and multivariate analysis it was found that all oncologic parameters were influenced by preoperative treatment and radicality of the resection. Patients who were re-irradiated had a similar outcome compared to patients, who were radiotherapy naive and could undergo full-course treatment, except the chance of local re-recurrence was higher for re-irradiated patients. Waiting-time between preoperative radiotherapy and IOERT was inversely correlated with the chance of local re-recurrence, and positively correlated with the chance of a R0 resection.

CONCLUSIONS

R0 resection is the most important factor influencing oncologic parameters in treatment of LRRC. Preoperative (chemo)-radiotherapy increases the chance of achieving radical resections and improves oncologic outcomes. Short waiting-times between preoperative treatment and IOERT improves the effectiveness of IOERT to reduce the chance of a local re-recurrence.

Radiotherapy for Colorectal Cancer: Current Standards and Future Perspectives

BACKGROUND

Multimodal treatment approaches are indispensable for patients with advanced-stage colorectal cancer. Radiotherapy has been established as essential part of perioperative concepts and was introduced as an option to face challenges such as local relapse or oligometastases.

METHODS

A literature review was performed to summarize evidence and current standards of radiotherapeutic concepts in the treatment of colorectal cancer.

RESULTS

For stage II/III rectal cancer, neoadjuvant radiotherapy is superior to adjuvant treatment. Two preoperative regimens have been established and are commonly used with different objectives: short-course radiotherapy (SC-RT) and long-course chemoradiotherapy (LC-CRT). Both reduce the risk of local relapse. Additionally, LC-CRT aims at downsizing the tumor to potentially reduce radicalness of surgery. There is increasing evidence that not all stage II/III rectal cancer patients need neoadjuvant irradiation but also that in some cases surgery might be omitted. Stereotactic body radiotherapy (SBRT) of the liver shows high rates of local control in oligometastatic patients. Intraoperative and particle radiotherapy extend the spectrum of treatment options for locally recurrent patients.

CONCLUSION

Radiotherapeutic concepts are crucial for the primary management of locally advanced colorectal cancer and can essentially contribute to treatment approaches in locally recurrent, oligometastatic or palliative patients.

Safety and efficacy of intraoperative iodine-125 seed implantation brachytherapy for rectal cancer patients: A retrospective clinical research

BACKGROUND

This pilot study was performed to evaluate the risk of anastomotic leakage (AL) and pelvic autonomic nerve dysfunction, and the effects of (125) I brachytherapy after intraoperative permanent implantation of iodine-125 seeds within the patients with rectal carcinoma.

METHODS

In a cohort consisting of 80 rectal cancer patients who received potentially curative resection of rectal carcinoma with implantation of (125) I brachytherapy or radical resection of rectal carcinoma underwent total mesorectal excision. The incidences of AL, fecal incontinence, urinary dysfunction, and sexual dysfunction were calculated for comparison, and risk factors for these complications were analyzed by logistic regression. Rates of tumor recurrence and overall survival were evaluated.

RESULTS

Six out of 17 (35.29%) patients in the (125) I implant group and 1 out of 34 (2.94%) patients in the non-implant group were complicated with AL (P = 0.006). The incidences of urinary dysfunction (P = 0.005) and fecal incontinence (P = 0.023) were significantly different between the two groups. Multivariate analyses revealed that (125) I brachytherapy was an independent risk factor for AL (odds ratio, 18.702; 95%CI, 1.802-194.062; P = 0.014) and urinary dysfunction (odds ratio, 4.340; 95%CI, 1.158-16.264; P = 0.029), respectively. At postoperative 2-year, the recurrence rates were 5.56% in the (125) I implant group and 9.09% in the non-implant group (P = 0.029).

CONCLUSIONS

Intraoperative implantation of (125) I brachytherapy significantly increases the risk of AL, fecal incontinence, urinary dysfunction, and improves local control and do not improve overall survival after total mesorectal excision.

Irradiation of Very Locally Advanced and Recurrent Rectal Cancer

Adjuvant therapy with chemoradiation or short-course radiation in addition to improvements in surgical technique has led to improved outcomes for patients with locally advanced rectal cancer. Local recurrence rates of less than 10% and 5-year survival rate of 60% or higher is expected. However, for patients with very locally advanced primary or locally recurrent disease in whom surgical resection is likely to be associated with incomplete resection, survival and disease control rates are poor and standard doses of adjuvant radiation or chemoradiation are relatively ineffective. Dose-escalation approaches with intraoperative radiation (IORT) have been explored in both the primary and recurrent setting. Although high-level evidence is lacking, available data suggest improvements in local and distant control leading to improved survival with IORT approaches. This review summarizes the evidence for dose-escalation approaches with IORT for patients with very locally advanced and recurrent rectal cancer.

Treatment of Locally Recurrent Rectal Carcinoma in Previously (Chemo)Irradiated Patients: A Review

BACKGROUND

Local recurrence after rectal cancer treatment occurs in ≈5% to 10% of patients. Neoadjuvant (chemo)radiotherapy for primary rectal cancer renders treatment of recurrent disease more difficult.

OBJECTIVE

The purpose of this study was to review contemporary multimodality therapies, including their outcome, for locally recurrent rectal carcinoma after (chemo)radiotherapy and complete surgical resection of primary rectal cancer.

DATA SOURCES

A comprehensive literature search of PubMed and EMBASE was performed.

STUDY SELECTION

All English language articles presenting original patient data regarding treatment and the respective outcome of previously irradiated locally recurrent rectal cancer were included.

INTERVENTIONS

All of the treatment modalities for locally recurrent rectal cancer were reviewed.

MAIN OUTCOME MEASURES

Primary outcome parameters were local control, metastasis-free survival, and overall survival. Secondary outcome parameters were perioperative morbidity and mortality, and prognostic factors for treatment outcome.

RESULTS

Of 854 studies, 9 studies and 474 patients with locally recurrent rectal carcinoma were included. Various treatment regimens were used, most with curative intent. Reirradiation was composed of (neo-)adjuvant external beam radiotherapy (with or without concurrent chemotherapy), additional intraoperative radiotherapy, or intraoperative radiotherapy only. Surgical technique highly varied, depending on the extent of the lesion. Radiation toxicity, perioperative morbidity, and mortality were generally acceptable. Outcome was better after curative intent treatment, any surgical resection, and R0 resections in particular. Moreover, reirradiation is associated with increased complete resection rates, which in turn positively affected local control and overall survival.

LIMITATIONS

Most studies were retrospectively designed, with highly variable therapies, patient populations, and duration of follow-up.

CONCLUSIONS

A complete resection is the most important prognostic factor and should be the goal of treatment in locally recurrent rectal carcinoma. Reirradiation seems safe and of additional value in reaching a complete resection. Considering the available evidence, at present reirradiation should be given on a case-specific basis, with all of the patients entering an international prospective database.

Development of a conceptual framework of health-related quality of life in locally recurrent rectal cancer

AIM

The surgical management of locally recurrent rectal cancer (LRRC) has become widely accepted to afford cure and improve quality of life in this subset of patients. Thus far, traditional surgical and oncological markers have been used to highlight the success of surgical intervention. The use of patient-reported outcomes, specifically health-related quality of life (HRQoL), is sparse in these patients. This may be in part due to the lack of well-designed, validated instruments. This study identifies HRQoL issues relevant to patients undergoing surgery for LRRC, with the aim of developing a conceptual framework of HRQoL specific to LRRC to enable measurement of patient-reported outcomes in this cohort of patients.

METHOD

Qualitative focus groups were undertaken at two institutions to identify relevant HRQoL themes. The principles of thematic content analysis were used to analysis data. NViVo10 was used to analyse data.

RESULTS

Twenty-one patients participated in six consecutive focus groups. Two patterns of themes emerged related to HRQoL and healthcare service delivery and utilization. Identified themes related to HRQoL included symptoms, sexual function, psychological impact, role and social functioning and future perspective. Under healthcare service and delivery and utilization the subdomain of disease management, treatment expectations and healthcare professionals were identified.

CONCLUSION

This is the first qualitative study undertaken exclusively in patients with LRRC to ascertain relevant HRQoL outcomes. The impact of LRRC on patients is wide-ranging and extends beyond traditional HRQoL outcomes. The study operationalizes the identified outcomes into a conceptual framework, which will provide the basis for the development of a LRRC-specific patient-reported outcome measure.