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

Clinical feasibility of combining intraoperative electron radiation therapy with minimally invasive surgery: a potential for electron-FLASH clinical development

BACKGROUND

Local cancer therapy by combining real-time surgical exploration and resection with delivery of a single dose of high-energy electron irradiation entails a very precise and effective local therapeutic approach. Integrating the benefits from minimally invasive surgical techniques with the very precise delivery of intraoperative electron irradiation results in an efficient combined modality therapy.

METHODS

Patients with locally advanced disease, who are candidates for laparoscopic and/or thoracoscopic surgery, received an integrated multimodal management. Preoperative treatment included induction chemotherapy and/or chemoradiation, followed by laparoscopic surgery and intraoperative electron radiation therapy.

RESULTS

In a period of 5 consecutive years, 125 rectal cancer patients were treated, of which 35% underwent a laparoscopic approach. We found no differences in cancer outcomes and tolerance between the open and laparoscopic groups. Two esophageal cancer patients were treated with IOeRT during thoracoscopic resection, with the resection specimens showing intense downstaging effects. Two oligo-recurrent prostatic cancer patients (isolated nodal progression) had a robotic-assisted surgical resection and post-lymphadenectomy electron boost on the vascular and lateral pelvic wall.

CONCLUSIONS

Minimally invasive and robotic-assisted surgery is feasible to combine with intraoperative electron radiation therapy and offers a new model explored with electron-FLASH beams.

[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.

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.

Role of intraoperative radiotherapy in the treatment of sacral chordoma

BACKGROUND CONTEXT

Sacral chordoma is a rare entity with high local recurrence rates when complete resection is not achieved. To date, there are no series available in literature combining surgery and intraoperative radiotherapy (IORT).

PURPOSE

The objective of this study was to report the experience of our center in the management of sacral chordoma combining radical resection with both external radiotherapy and IORT.

STUDY DESIGN

This is a retrospective case series.

PATIENT SAMPLE

The patient sample included 15 patients with sacral chordoma resected in our center from 1998 to 2015.

OUTCOME MEASURES

The outcome measures were overall survival (OS), disease-free survival (DFS), and rates of local and distant recurrences.

METHODS

We retrospectively reviewed the records of all the patients with sacral chordoma resected in our center from 1998 to December 2015. Overall survival, DFS, and rates of local and distant recurrences were calculated. Results between patients treated with or without IORT were compared.

RESULTS

A total of 15 patients were identified: 8 men and 7 women. The median age was 59 years (range 28-77). Intraoperative radiotherapy was applied in nine patients and six were treated with surgical resection without IORT. In 13 patients, we performed the treatment of the primary tumor, and in two patients, we performed the treatment of recurrence disease. A posterior approach was used in four patients. Wide surgical margins (zero residue) were achieved in six patients, marginal margins (microscopic residue) were achieved in seven patients, and there were no patients with intralesional (R2) margins. At a median follow-up of 38 months (range 11-209 months), the 5-year OS in the IORT group was 100% versus 53% in the group of non-IORT (p=.05). The median DFS in the IORT group was 85 months, and that in the non-IORT group was 41 months. In the group without IORT, two patients died and nobody died during the follow-up in the group treated with IORT. High-sacrectomy treated patients had a median survival of 41 months, and low-sacrectomy treated patients had a median survival of 90 months. Disease-free survival in patients without gluteal involvement was 100% at 5 years, and that in patients with gluteal involvement was 40%. All patients with a recurrence in our study had gluteal involvement.

CONCLUSIONS

Multidisciplinary management of sacral chordoma seems to improve local control. The use of IORT, in our experience, is associated with an increase in OS and DFS. The level of resection and gluteal involvement seems to affect survival. The posterior approach is useful in selected cases. Multicenter studies should be performed to confirm the utility of IORT.

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.

Evaluation of LiF:Mg,Ti (TLD-100) for Intraoperative Electron Radiation Therapy Quality Assurance

BACKGROUND

Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs) response to intraoperative electron radiation therapy (IOERT) beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2-12 cGy/pulse) during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.

METHODS

LiF:Mg,Ti dosimeters (TLD-100) were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV) and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0-10 Gy in step of 2 Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.

RESULTS

The TLD-100 dose-response curves were obtained. In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).

CONCLUSIONS

This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.

Intraoperative radiotherapy for gastrointestinal malignancies: contemporary outcomes with multimodality therapy

The integration of intraoperative radiotherapy (IORT) into the multimodal treatment of gastrointestinal cancer is feasible and leads to high rates of local control. In-field tumoral control using IORT-containing strategies can be achieved in over 90 % of most cases, regardless of the site or status of the tumor (primary or recurrent). Electron beam IORT, or intraoperative electron radiation therapy, is the dominant technology used in institutions reporting data in publications the 21st century. Neither surgery nor systemic therapy is compromised by the integration of IORT-containing radiotherapy.

Benefits from adjuvant intraoperative radiotherapy treatment for gastric cancer: A meta-analysis

The benefits of adjuvant intraoperative radiotherapy (IORT) for resectable gastric cancer have been extensively studied, but data on the survival rate remains equivocal. A meta-analysis was performed of the studies involving the use of IORT for resectable gastric cancer using web-based databases. Hazard ratios (HRs) describing the impact of adjuvant IORT on the overall survival (OS) rate and locoregional control were extracted directly from the original studies or calculated from survival curves. A meta-analysis of four studies that provided OS data revealed that IORT had no significant impact on OS [HR, 0.97; 95% confidence interval (CI), 0.75-1.26; P=0.837]. In the three studies testing the efficacy of IORT for OS in the subgroup of patients with stage III disease, there was a significantly improved OS (HR, 0.60; 95% CI, 0.40-0.89; P=0.011). Significant locoregional control improvement was observed in the four studies that provided locoregional control data (HR 0.40; 95% CI, 0.26-0.62; P<0.001). This meta-analysis showed a statistically significant locoregional control benefit with the addition of IORT in patients with resectable gastric cancer. In addition, the available data revealed that adjuvant IORT may provide promising results on the survival rate for the subgroup of patients with stage III disease. Further study is required to optimize the implementation of adjuvant IORT for gastric cancer with regard to patient selection and integration with systemic therapy.

Bibliometrics of intraoperative radiotherapy: analysis of technology, practice and publication tendencies

PURPOSE

To analyze the performance and quality of intraoperative radiation therapy (IORT) publications identified in medical databases during a recent period in terms of bibliographic metrics.

MATERIALS AND METHODS

A bibliometric search was conducted for IORT papers published in the PubMed database between 1997 and 2013. Publication rate was used as a quantity indicator; the 2012 Science Citation Index Impact Factor as a quality indicator. Furthermore, the publications were stratified in terms of study type, scientific topic reported, year of publication, tumor type and journal specialty. We performed a one-way analysis of variance (ANOVA) to determine differences between the means of the analyzed groups.

RESULTS

Among the total of 207 journals, articles were reported significantly more frequently in surgery (n = 399, 41 %) and radiotherapy journals (n = 273, 28 %; p < 0.01). The highest impact factor was achieved by clinical oncology journals (p < 0.01). The majority of identified articles were retrospective cohort reports (n = 622, 64 %), followed by review articles (n = 204, 21 %; p < 0.001). Regarding primary topic, reports on cancer outcome following specific tumor therapy were most frequently published (n = 661, 68 %; p < 0.001) and gained the highest mean impact factor (p < 0.01). Gastrointestinal tumor reports were represented most frequently (n = 456, 47 %; p < 0.001) and the mean superior impact factor was earned by breast and gynecologic publications (p < 0.01).

CONCLUSION

We identified a consistent and sustained scientific productivity of international IORT expert groups. Most publications appeared in journals with surgical and radiooncological content. The highest impact factor was achieved by medical oncology journals.

Present status and future directions of intraoperative radiotherapy

In this Review, we summarise recent published work on the use of intraoperative radiotherapy to treat common tumour sites in the primary or recurrent setting. Techniques, radiobiology, and the physics of intraoperative radiotherapy are also explored. Disease sites discussed in this Review include head and neck cancer, breast cancer, sarcoma, gastrointestinal cancer, genitourinary cancer, gynaecological cancer, thoracic cancer, and palliative applications.

Intraoperative radiotherapy with electrons: fundamentals, results, and innovation

Rationale and objectives

To analyse the programme activity and clinical innovation and/or technology developed over a period of 17 years with regard to the introduction and the use of intraoperative radiotherapy (IORT) as a therapeutic component in a medical–surgical multidisciplinary cancer hospital.

Material and methods

To standardise and record this procedure, the Radiation Oncology service has an institutional programme and protocols that must be completed by the different specialists involved. For 17 years, IORT procedures were recorded on a specific database that includes 23 variables with information recorded on institutional protocols.

As part of the development and innovation activity, two technological tools were implemented (RADIANCE and MEDTING) in line with the standardisation of this modality in clinical practice.

Results

During the 17 years studied, 1,004 patients were treated through 1,036 IORT procedures. The state of the disease at the time of IORT was 77% primary and 23% recurrent. The origin and distribution of cancers were 62% gastrointestinal, 18% sarcomas, 5% pancreatic, 2% paediatric, 3% breast, 7% less common locations, and 2% others. The research and development projects have generated a patent on virtual planning (RADIANCE) and proof of concept to explore as a professional social network (MEDTING).

During 2012, there were 69 IORT procedures. There was defined treatment volume (target or target region) in all of them, and 43 were conducted by the virtual planning RADIANCE system. Eighteen have been registered on the platform MEDTING as clinical cases.

Conclusion

The IORT programme, developed in a university hospital with an academic tradition, and interdisciplinary surgical oncology, is a feasible care initiative, able to generate the necessary intense clinical activity for tending to the cancer patient. Moreover, it is a competitive source for research, development, and scientific innovation.

Intraoperative radiation therapy opportunities for clinical practice normalization: Data recording and innovative development

BACKGROUND

Intraoperative radiotherapy (IORT) refers to the delivery of a high dose of radiation at the time of surgery.

AIM

To analyze clinical and research-oriented innovative activities developed in a 17-year period using intraoperative electron-radiation therapy (IOeRT) as a component of treatment in a multidisciplinary approach for cancer management.

MATERIALS AND METHODS

From 01/1995 to 03/2012 IOeRT procedures were registered in a specific Hospital-based database. Research and developments in imaging and recording for treatment planning implementation are active since 2006.

RESULTS

1004 patients were treated and 1036 IORT procedures completed. Median age of patients was 61 (range 5 months to 94 years). Gender distribution was male in 54% of cases and female in 46%. Disease status at the time of IORT was 796 (77%) primary and 240 (23%) recurrent. Cancer type distribution included: 62% gastrointestinal, 18% sarcoma, 5% pancreas, 2% paediatric, 3% breast, 77 7% oligotopic recurrences, 2% other. IORT technical characteristics were: Applicator size 5 cm 22%, 6 cm 21%, 7 cm 21%, 8 cm 15%, 9 cm 6%, 10 cm 7% 12 cm 5% 15 cm 3%. Electron energies: 6 MeV 19%, 8 MeV 15%, 10 MeV 15%, 12 MeV 23%, 15 MeV 19%, 18 MeV 6%, other 3%. Multiple fields: 108 (11%). Dose: 7.5 Gy 3%, 10 Gy 35%, 12 Gy 3%, 12.5 Gy 49%, 15 Gy 5%, other 5%.

CONCLUSION

An IORT programme developed in an Academic Hospital based on practice-oriented medical decisions is an attractive interdisciplinary oncology initiative proven to be able to generate an intensive clinical activity for cancer patient quality care and a competitive source of scientific patient-oriented research, development and innovation.

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

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