Patterns of failure and local control after intraoperative electron boost radiotherapy to the presacral space in combination with total mesorectal excision in patients with locally advanced rectal cancer

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.

Commissioning, dosimetric characterization and machine performance assessment of the LIAC HWL mobile accelerator for Intraoperative Radiotherapy

BACKGROUND

The LIAC HWL (Sordina IORT Technologies, Vicenza, Italy) is a recently designed mobile linear accelerator for intraoperative electron radiotherapy (IOeRT), producing high dose rate electron beams at four different energy levels. It features a software tool for the visualization of 2D dose distributions, which is based on Monte Carlo simulations. The aims of this work were to (i) assess the dosimetric characteristics of the accelerator, (ii) experimentally verify calculated data exported from the software and (iii) report on commissioning as well as performance of the system during the first year of operation.

METHODS

The electron energies of the LIAC HWL used in this study are 6, 8, 10 and 12 MeV. Diameters of the cylindrically shaped applicators range from 3 to 10cm. We studied two applicator sets with different length ratios of proximal and terminal applicator sections. Reference dosimetry, linearity as well as short- and long-term stability were measured with a PTW Advanced Markus chamber, relative depth dose and profiles were measured using an unshielded diode. Percentage-depth-dose (PDD) and transversal dose profile (TDP) data were exported from the simulation software LIACSim and compared with our measurements.

RESULTS

The device reaches dose rates up to 40Gy/min (for 12 MeV). Surface doses for the 10cm applicators are higher than 90%, X-ray background is below 0.6% for all energies. Simulations and measurements of PDD agreed well, with a maximum difference in the depth of the 50% isodose of 0.7mm for the flat-ended applicators and 1mm for the beveled applicators. The simulations slightly underestimate the dose in the lateral parts of the field (difference < 1.8% for flat-ended applicators). The two different applicator sets were dosimetrically equivalent. Long-term stability measurements for the first year of operation ranged from -2.1% to 1.6% (mean: -0.1%).

CONCLUSIONS

The system is dosimetrically well suited for IOeRT and performed stably and reliably. The software tool for visualization of dose distributions can be used to support treatment planning, following thorough validation.

[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.

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

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

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.

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.

Prognostic implications of MRI-detected lateral nodal disease and extramural vascular invasion in rectal cancer

BACKGROUND

Lateral nodal disease in rectal cancer remains a subject of debate and is treated differently in the East and the West. The predictive value of lateral lymph node and MRI-detected extramural vascular invasion (mrEMVI) features on oncological outcomes was assessed in this study.

METHODS

In this retrospective cohort study, data on patients with cT3-4 rectal cancer within 8 cm from the anal verge were considered over a 5-year period (2009-2013). Lateral lymph node size, malignant features and mrEMVI features were evaluated and related to oncological outcomes.

RESULTS

In total, 192 patients were studied, of whom 30 (15·6 per cent) underwent short-course radiotherapy and 145 (75·5 per cent) received chemoradiotherapy. A lateral lymph node short-axis size of 10 mm or more was associated with a significantly higher 5-year lateral/presacral local recurrence rate of 37 per cent, compared with 7·7 per cent in nodes smaller than 10 mm (P = 0·041). Enlarged nodes did not result in a higher 5-year rate of distant metastasis (23 per cent versus 27·7 per cent in nodes smaller than 10 mm; P = 0·563). However, mrEMVI positivity was related to more metastatic disease (5-year rate 43 versus 26·3 per cent in the mrEMVI-negative group; P = 0·014), but not with increased lateral/presacral recurrence. mrEMVI occurred in 46·6 per cent of patients with nodes smaller than 10 mm, compared with 29 per cent in patients with nodes of 10 mm or larger (P = 0·267).

CONCLUSION

Although lateral nodal disease is more a local problem, mrEMVI mainly predicts distant recurrence. The results of this study showed an unacceptably high local recurrence rate in patients with a short axis of 10 mm or more, despite neoadjuvant (chemo)radiotherapy.

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.

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.

Clinical outcome of interstitial pulsed dose rate brachytherapy in multimodality treatment of locally advanced primary or recurrent rectal and sigmoid cancer with high risk of incomplete microscopic resection

OBJECTIVE

To evaluate the role of interstitial pulsed dose rate brachytherapy (PDR-BT) in multimodality treatment of locally advanced primary or recurrent rectal and sigmoid cancer with high risk of microscopic incomplete resection (R1).

METHODS AND MATERIAL

A total of 73 consecutive patients (recurrent/primary: 40/33) were treated with PDR-BT between 2001 and 2010. Patients received preoperative external beam radiotherapy (EBRT) and concomitant chemotherapy. Following resection of the tumor and the involved pelvic organs, a median of four (3-8) catheters were sutured to the tumor bed with a distance of approximately 1 cm between the catheters. A target respecting the catheters with a margin of 5 mm was contoured on computed tomography (CT) and three-dimensional (3D) dose planning with a planning aim for BT of D90 > 30 Gy, (0.6 Gy/pulse, 1 pulse/h) was performed. Previously irradiated patients (27%) underwent surgery that was directly followed by PDR-BT. Postoperative EBRT was then applied to the tumor bed 3-5 weeks after PDR-BT.

RESULTS

A total of 23 patients (31%) received a radical resection (R0) and 45 patients (62%) received an R1 resection. Five patients (7%) received a macroscopic incomplete resection (R2). The five-year overall survival was 33%. Local control at five years was 67% for patients who received a R0 resection and 32% for patients who received an R1 resection. The five-year actuarial risk of a grade 3-4 BT-related complication was 5%.

CONCLUSIONS

Meaningful disease control and survival can be obtained at an acceptable rate of late morbidity in selected patients with locally advanced primary and recurrent rectal or sigmoid cancer using (chemo) RT, extensive surgery and PDR-BT when a high risk of an R1 resection is expected.

Post-chemoradiation intraoperative electron-beam radiation therapy boost in resected locally advanced rectal cancer: long-term results focused on topographic pattern of locoregional relapse

BACKGROUND

Patients with locally advanced rectal cancer (LARC) have a dismal prognosis. We investigated outcomes and risk factors for locoregional recurrence (LRR) in patients treated with preoperative chemoradiotherapy (CRT), surgery and IOERT.

METHODS

A total of 335 patients with LARC [⩾cT3 93% and/or cN+ 69%) were studied. In multivariate analyses, risk factors for LRR, IFLR and OFLR were assessed.

RESULTS

Median follow-up was 72.6 months (range, 4-205). In multivariate analysis distal margin distance ⩽10 mm [HR 2.46, p = 0.03], R1 resection [HR 5.06, p = 0.02], tumor regression grade 1-2 [HR 2.63, p = 0.05] and tumor grade 3 [HR 7.79, p < 0.001] were associated with an increased risk of LRR. A risk model was generated to determine a prognostic index for individual patients with LARC.

CONCLUSIONS

Overall results after multimodality treatment of LARC are promising. Classification of risk factors for LRR has contributed to propose a prognostic index that could allow us to guide risk-adapted tailored treatment.

Intraoperative radiotherapy for locally advanced or locally recurrent rectal cancer: Does it work at all?

BACKGROUND

Intraoperative radiotherapy (IORT) has been given for primary and locally recurrent rectal cancer for 30 years. Still, its effect is not clear.

MATERIAL AND METHODS

PubMed and EMBASE search for papers after 1989 on surgical treatment and external beam radiotherapy (EBRT) for primary advanced and locally recurrent rectal cancer, with and without IORT. From each center the most recent paper was generally selected. Survival and local recurrence at five years was tabulated for the total groups and separate R-stages. Also, the technique for IORT, use of EBRT and chemotherapy as well as surgical approach was registered.

RESULTS

In primary cancer 18 papers from 14 centers were tabulated, including one randomized and five internally comparing studies, as well as seven studies without IORT. In locally recurrent cancer 18 papers from 13 centers were tabulated, including four internally comparing studies and also five without IORT. Overall survival (OS) and local recurrence rate (LRR) were higher for primary cancer compared to recurrent cancer. Patients with R0 resections had better outcome than patients with R1 or R2 resections. For primary cancer OS and LR rate of the total groups and R0 stages was not influenced by IORT. An effect on R1/R2 stages cannot be excluded. The only randomized study (primary cancer) did not show any effect of IORT.

CONCLUSION

IORT does not convincingly improve OS and LR rate for primary and locally recurrent rectal cancer. If there is an effect of IORT, it is small and cannot be shown outside randomized studies analyzing the separate R stages.

Intraoperative radiation therapy reduces local recurrence rates in patients with microscopically involved circumferential resection margins after resection of locally advanced rectal cancer

PURPOSE

Intraoperative radiation therapy (IORT) is advocated by some for patients with locally advanced rectal cancer (LARC) who have involved or narrow circumferential resection margins (CRM) after rectal surgery. This study evaluates the potentially beneficial effect of IORT on local control.

METHODS AND MATERIALS

All surgically treated patients with LARC treated in a tertiary referral center between 1996 and 2012 were analyzed retrospectively. The outcome in patients treated with IORT with a clear but narrow CRM (≤2 mm) or a microscopically involved CRM was compared with the outcome in patients who were not treated with IORT.

RESULTS

A total of 409 patients underwent resection of LARC, and 95 patients (23%) had a CRM ≤ 2 mm. Four patients were excluded from further analysis because of a macroscopically involved resection margin. In 43 patients with clear but narrow CRMs, there was no difference in the cumulative 5-year local recurrence-free survival of patients treated with (n=21) or without (n=22) IORT (70% vs 79%, P=.63). In 48 patients with a microscopically involved CRM, there was a significant difference in the cumulative 5-year local recurrence-free survival in favor of the patients treated with IORT (n=31) compared with patients treated without IORT (n=17) (84 vs 41%, P=.01). Multivariable analysis confirmed that IORT was independently associated with a decreased local recurrence rate (hazard ratio 0.24, 95% confidence interval 0.07-0.86). There was no significant difference in complication rate of patients treated with or without IORT (65% vs 52%, P=.18) CONCLUSION: The current study suggests that IORT reduces local recurrence rates in patients with LARC with a microscopically involved CRM.

Intraoperative radiation therapy for locally advanced primary and recurrent colorectal cancer: ten-year institutional experience

BACKGROUND

We evaluated the role of intraoperative radiation therapy (IORT) during radical resection of locally advanced colorectal cancer (CRC).

METHODS

We retrospectively evaluated all patients with CRC treated with IORT at our institution from 2001 to 2010. IORT was delivered using high-dose-rate brachytherapy (median 12.5-Gy). We analyzed factors associated with postoperative morbidity, local control (LC), and overall survival (OS).

RESULTS

One hundred patients were evaluated with 70% received IORT for recurrent tumors. R0 resection rate was 58%. Postoperative Grade ≥3 complications (33%) were independently associated with transfusions ≥3 units packed red blood cells (P = 0.016) and body mass index (BMI) ≥35 (P = 0.0499). Eighty-two patients underwent external beam radiation therapy (EBRT) before IORT. Five-year LC was 94%, for primary and 56%, for recurrent tumors, respectively (P = 0.007). Microscopic positive (R1) margins were not associated with LC (P = 0.316). BMI ≥30 (P = 0.048) and post-discharge complications (P = 0.041) were independent risk factors for worse LC. Median post-IORT OS was 67.7 (95% CI 51.1-84.3) months for all patients.

CONCLUSION

For patients with primary or recurrent locally advanced CRC, treatment with radical surgery and IORT achieved excellent LC outcomes irrespective of microscopic margin status. IORT may be indicated for tumors suspected to have close or positive microscopic margins.

T4 rectal cancer: do we always need an exenteration?

The management of rectal cancer has changed dramatically over the last few decades. Due to improvements in the multimodality treatment and the introduction of neoadjuvant chemoradiation, previously irresectable tumours can nowadays be cured by extensive multivisceral resections. These highly complex operations are associated with significant morbidity and mortality. Due to optimization of chemoradiotherapy, the introduction of IORT, increasing knowledge of tumour pathology and patterns of recurrence the need for extensive surgery diminishes. The question arises which patients with T4 rectal cancer really need extensive surgery and who can safely be considered for an organ preserving approach.

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

BACKGROUND AND PURPOSE

Anastomotic recurrence after radical sphincter-preserving surgery preceded by neoadjuvant therapy in locally advanced rectal cancer is an uncommon event that merits further assessment. The aim of this study is to analyze the effect of preoperative chemoradiation on the risk of anastomotic recurrence. Based on the initial extension of the tumor, we analyzed whether the distal surgical section was calculated through the virtual initial extension of the rectal tumor.

PATIENTS AND METHODS

Eligible patients with locally advanced rectal cancer were offered preoperative chemoradiation, sphincter sparing surgery and intraoperative radiation therapy boost.

RESULTS

180 patients were treated with anterior resection (40 %), low anterior resection (45.6 %) and ultra-low anterior resection (14.4 %). With a median follow-up of 41.1 months (0.36-143 months), anastomotic recurrence was diagnosed in 9 patients (5 %). There was no statistical correlation with downstaging (T or N), downsizing effects, or with distance from the lower limit of the residual lesion to the distal margin. Virtual intratumoral surgical section was speculated in 44 patients (3 developed anastomotic recurrence; 6.8 vs 4.8 %, p = 0.482).

CONCLUSION

Anastomotic recurrence in patients with rectal cancer treated with neoadjuvant chemoradiation is an infrequent event. Virtual intratumoral surgical sections followed by anastomosis do not contribute to an excessive risk of recurrence. Our findings encourage the development of policies for preservation of the ano-rectal complex in rectal cancer patients.

Patterns of Practice in the Radiation Therapy Management of Rectal Cancer: Survey of the Interregional Group Piedmont, Valle d'Aosta and Liguria of the “Associazione Italiana di Radioterapia Oncologica (AIRO)”

Aims and background

To report the survey about the main aspects on the use of radiotherapy for the treatment of rectal cancer in Piedmont and Liguria.

Methods and study design

Sixteen centers (11 from Piedmont and 5 from Liguria) received and answered by email a questionnaire data base about clinical and technical aspects of the treatment of rectal cancer. All data were incorporated in a single data base and analyzed.

Results

Data regarding 593 patients who received radiotherapy for rectal cancer during the year 2009 were collected and analyzed. Staging consisted in colonoscopy, thoracic and abdominal CT, pelvic MRI and endoscopic ultrasound. PET/CT was employed to complete staging and in the treatment planning in 12/16 centers (75%). Neoadjuvant radiotherapy was employed more frequently than adjuvant radiotherapy (50% vs 36.4%), using typically a total dose of 45 Gy with 1.8 Gy/fraction. Concurrent chemoradiation with 5-fluorouracil or capecitabine was mainly employed in neoadjuvant and adjuvant settings, whereas oxaliplatin alone or in combination with 5-FU or capecitabine and leucovorin was commonly employed as the adjuvant agent. The median interval from neoadjuvant treatment to surgery was 7 weeks after long-course radiotherapy and 8 days after short-course radiotherapy. The pelvic total dose of 45 Gy in the adjuvant setting was the same in all the centers. Doses higher than 45 Gy were employed with a radical intent or in case of positive surgical margins. Hypofractionated regimens (2.5, 3 Gy to a total dose of 35–30 Gy) were used in the palliative setting. No relevant differences were observed in target volume definition and patient setup. Twenty-six patients (4.4%) developed grade 3 acute toxicity. Follow-up was scheduled in a similar way in all the centers.

Conclusions

No relevant differences were found among the centers involved in the survey. The approach can help clinicians to address important clinical questions and to improve consistency and homogeneity of treatments.

Intraoperative radiotherapy in colorectal cancer: systematic review and meta-analysis of techniques, long-term outcomes, and complications

BACKGROUND

The precise contribution of IORT to the management of locally advanced and recurrent colorectal cancer (CRC) remains uncertain. We performed a systematic review and meta-analysis to assess the value of IORT in this setting.

METHODS

Studies published between 1965 and 2011 that reported outcomes after IORT for advanced or recurrent CRC were identified by an electronic literature search. Studies were assessed for methodological quality and design, and evaluated for technique of IORT delivery, oncological outcomes, and complications following IORT. Outcomes were analysed with fixed-effect and random-effect model meta-analyses and heterogeneity and publication bias examined.

RESULTS

29 studies comprising 14 prospective and 15 retrospective studies met the inclusion criteria and were assessed, yielding a total of 3003 patients. The indication for IORT was locally advanced disease in 1792 patients and locally recurrent disease in 1211 patients. Despite heterogeneity in methodology and reporting practice, IORT is principally applied for the treatment of close or positive margins. When comparative studies were evaluated, a significant effect favouring improved local control (OR 0.22; 95% CI = 0.05-0.86; p = 0.03), disease free survival (HR 0.51; 95% CI = 0.31-0.85; p = 0.009), and overall survival (HR 0.33; 95% CI = 0.2-0.54; p = 0.001) was noted with no increase in total (OR 1.13; 95% CI = 0.77-1.65; p = 0.57), urologic (OR 1.35; 95% CI = 0.84-2.82; p = 0.47), or anastomotic complications (OR 0.94; 95% CI = 0.42-2.1; p = 0.98). Increased wound complications were noted after IORT (OR 1.86; 95% CI = 1.03-3.38; p = 0.049).

CONCLUSIONS

Despite methodological weaknesses in the studies evaluated, our results suggest that IORT may improve oncological outcomes in advanced and recurrent CRC.

Intraoperative Electron Radiation Therapy (IOERT) in the management of locally recurrent rectal cancer

BACKGROUND

To evaluate disease control, overall survival and prognostic factors in patients with locally recurrent rectal cancer after IOERT-containing multimodal therapy.

METHODS

Between 1991 and 2006, 97 patients with locally recurrent rectal cancer have been treated with surgery and IOERT. IOERT was preceded or followed by external beam radiation therapy (EBRT) in 54 previously untreated patients (median dose 41.4 Gy) usually combined with 5-Fluouracil-based chemotherapy (89%). IOERT was delivered via cylindric cones with doses of 10-20 Gy. Adjuvant CHT was given only in a minority of patients (34%). Median follow-up was 51 months.

RESULTS

Margin status was R0 in 37%, R1 in 33% and R2 in 30% of the patients. Neoadjuvant EBRT resulted in significantly increased rates of free margins (52% vs. 24%). Median overall survival was 39 months. Estimated 5-year rates for central control (inside the IOERT area), local control (inside the pelvis), distant control and overall survival were 54%, 41%, 40% and 30%. Resection margin was the strongest prognostic factor for overall survival (3-year OS of 80% (R0), 37% (R1), 35% (R2)) and LC (3-year LC 82% (R0), 41% (R1), 18% (R2)) in the multivariate model. OS was further significantly affected by clinical stage at first diagnosis and achievement of local control after treatment in the univariate model. Distant failures were found in 46 patients, predominantly in the lung. 90-day postoperative mortality was 3.1%.

CONCLUSION

Long term OS and LC can be achieved in a substantial proportion of patients with recurrent rectal cancer using a multimodality IOERT-containing approach, especially in case of clear margins. LC and OS remain limited in patients with incomplete resection. Preoperative re-irradiation and adjuvant chemotherapy may be considered to improve outcome.

Laparoscopic abdominoperineal resection with intraoperative radiotherapy for locally advanced low rectal cancer

AIMS

Intraoperative radiotherapy (IORT) for locally advanced rectal cancer as an integral part of multimodal treatment, may lead to reduced local recurrence but it is not routinely used. The aim of this paper is to describe our experience with IORT in the treatment of patients with locally advanced adenocarcinoma of the lower third of the rectum.

MATERIAL AND METHODS

Laparoscopic abdominoperineal amputation of the rectum with intraoperative radiotherapy was performed on 17 patients, 13 men and 4 women, median age 64 years (49-75 years) between 2010-2011. All patients underwent complete therapy according to the treatment protocol.

RESULTS

In one patient, the laparoscopic procedure had to be converted to an open resection. The duration of the surgical procedure with IORT was 185 to 345 min (median 285 min). In 14 cases, the intraoperative dose was 10 Gy and in two patients a dose of 12 Gy was used. There were no severe intraoperative complications. Blood loss ranged from 30 to 500 mL (median 100 mL). There were postoperative complications in 4 patients (23.5%); 2 necessitated surgical reintervention (11.8%). The duration of postoperative hospitalization was 6 to 35 days (median 7 days). In the follow-up of 2 to 16 months (median 12 months), no local recurrence or disease generalization have been found to date.

CONCLUSIONS

The results show the technical feasibility of laparoscopically assisted abdominoperineal amputation of the rectum in combination with IORT in the treatment of locally advanced rectal carcinoma with an acceptable risk of postperative complications.

Aggressive local treatment containing intraoperative radiation therapy (IORT) for patients with isolated local recurrences of pancreatic cancer: a retrospective analysis

Background

To evaluate the use of intraoperative radiation therapy (IORT) in the multimodality treatment of patients with isolated local recurrences of pancreatic cancer.

Methods

We retrospectively analyzed 36 patients with isolated local recurrences of pancreatic cancer who have been treated with a combination of surgery, IORT and EBRT. Median time from initial treatment to recurrence was 20 months. All patients were surgically explored. In 18 patients a gross total resection was achieved, whereas the other half received only debulking or no resection at all. All patients received IORT with a median dose of 15 Gy. Additional EBRT was applied to 31 patients with a median dose of 45 Gy, combined with concurrent, mainly gemcitabine-based chemotherapy.

Results

Median follow-up in surviving patients was 23 months. Local progression was found in 6 patients after a median time of 17 months, resulting in estimated 1- and 2-year local control rates of 91% and 67%, respectively. Distant failure was observed in 23 patients, mainly in liver or peritoneal space. The median estimated progression-free survival was 9 months with 1- and 2-year rates of 40% and 26%, respectively. We found an encouraging estimated median overall survival of 19 months, transferring into 1- and 2-year rates of 66% and 45%. Notably 6 of 36 patients (17%) lived for more than 3 years. Severe postoperative complications were found in 3 and chemoradiation-related grade III toxicity in 6 patients. No severe IORT related toxicity was observed.

Conclusion

Combination of surgery, IORT and EBRT in patients with isolated local recurrences of pancreatic cancer resulted in encouraging local control and overall survival in our cohort with acceptable toxicity. Our approach seems to be superior to palliative chemotherapy or chemoradiation alone and should be further investigated in a prospective setting specifically addressing isolated local recurrences of pancreatic cancer.

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

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

Origin of presacral local recurrence after rectal cancer treatment

Background

The objective of this study was to obtain detailed anatomical information about the lateral lymph nodes, in order to determine whether they might play a role in presacral local recurrence of rectal cancer after total mesorectal excision without lateral lymph node dissection.

Methods

Ten serially sectioned human fetal pelvises were studied at high magnification and a three-dimensional reconstruction of the fetal pelvis was made.

Results

Examination of the histological sections and the three-dimensional reconstruction showed that lateral lymph node tissue comprises a major proportion of the pelvic tissue volume. There were no lymph nodes located in the presacral area. Connections between the mesorectal and extramesorectal lymph node system were found in all fetal pelvises, located below the peritoneal reflection on the anterolateral side of the fetal rectum. At this site middle rectal vessels passed to and from the mesorectum, and branches of the autonomic nervous system bridge to innervate the rectal wall.

Conclusion

The findings of this study support the hypothesis that tumour recurrence might arise from lateral lymph nodes.

Patterns of local recurrence in locally advanced rectal cancer after intra-operative radiotherapy containing multimodality treatment

BACKGROUND AND PURPOSE

The purpose of this study is to analyze the patterns of local recurrence (LR) after intra-operative radiotherapy (IORT) containing multimodality treatment of locally advanced rectal carcinoma (LARC).

METHODS AND MATERIALS

Two hundred and ninety patients with LARC who underwent multimodality treatment between 1994 and 2006 were studied. For patients who developed LR, the subsite was classified into presacral, postero-lateral, lateral, anterior, anastomotic or perineal. Patient and treatment characteristics were related to subsite of LR.

RESULTS

After 5years, 34 patients (13.2%) developed LR. The most prominent subsite of LR was the presacral subsite. 47% of the local recurrences occurred outside the IORT field. Most recurrences developed when IORT was given dorsally, while least occurred when IORT was given ventrally. Especially after dorsal IORT a high amount of infield recurrences were observed (6 of 8; 75%). In multi-variate analysis tumor distance of more than 5cm from the anal verge and a positive circumferential margin were associated with presacral local recurrence.

CONCLUSIONS

Multimodality treatment is effective in the prevention of local recurrence in LARC. IORT application to the area most at risk is feasible and seems effective in the prevention of local recurrence. Dorsal tumor location results in unfavourable oncologic results.

IGRT in rectal cancer

To date, no great interest has been shown in the clinical implementation of recent Image-guided radiation therapy (IGRT) modalities in rectal cancer since only a few studies have been published on this issue. This may be explained by the fact that with current treatment modalities locoregional recurrences are already very low (around 10%). However, there is still room for improvement in treatment of high risk patients (cT3 CRM+, cT4, N+). In these patients better results may be obtained improving radiation technique from 2D to 3D, which showed to be more reliable in terms of target coverage. Also, when higher doses are delivered, Intensity Modulated Radiation Therapy (IMRT) may be used to spare small bowel. But before employing 3D irradiation or IMRT, a proper definition of our clinical target volume (CTV) and planning target volume (PTV) is needed. The CTV should encompass the tumour site, the mesorectum and the lateral nodes, recognized as the most likely sites of local recurrence, with different incidence according to tumour stage. Recent studies discussed the correct delineation of these target volumes in respect of tumour site and stage. From the preliminary results of a study conducted in Rome University 2D planning seemed insufficient to cover the different target volumes especially in T4 patients compared to 3D planning. Also an appropriate PTV margin is necessary in order to manage set-up errors and organ motion. Particularly in these patients, the knowledge of mesorectal movement is required to avoid target missing. Large mesorectal displacements were observed in a study carried out in Leuven University in collaboration with Rome University. A systematic review of the literature together with the data from these first experiences led to the awareness that IGRT could help us to follow the target volume and organs at risk during the treatment, allowing adjustments to improve accuracy in dose delivery, especially when dose escalation studies are planned in the treatment of rectal cancer.

Prototyping a large field size IORT applicator for a mobile linear accelerator

The treatment of large tumors such as sarcomas with intra-operative radiotherapy using a Mobetron is often complicated because of the limited field size of the primary collimator and the available applicators (max Ø100 mm). To circumvent this limitation a prototype rectangular applicator of 80 x 150 mm(2) was designed and built featuring an additional scattering foil located at the top of the applicator. Because of its proven accuracy in modeling linear accelerator components the design was based on the EGSnrc Monte Carlo simulation code BEAMnrc. First, the Mobetron treatment head was simulated both without an applicator and with a standard 100 mm applicator. Next, this model was used to design an applicator foil consisting of a rectangular Al base plate covering the whole beam and a pyramid of four stacked cylindrical slabs of different diameters centered on top of it. This foil was mounted on top of a plain rectangular Al tube. A prototype was built and tested with diode dosimetry in a water tank. Here, the prototype showed clinically acceptable 80 x 150 mm(2) dose distributions for 4 MeV, 6 MeV and 9 MeV, obviating the use of complicated multiple irradiations with abutting field techniques. In addition, the measurements agreed well with the MC simulations, typically within 2%/1 mm.

Clinical results of intraoperative radiation therapy for patients with locally recurrent and advanced tumors having colorectal involvement

BACKGROUND

Intraoperative radiation therapy (IORT) may be useful in the treatment of patients who have a locally advanced primary and recurrent abdominopelvic neoplasm with colorectal involvement.

METHODS

A retrospective review of colorectal cancer patients treated since 1999 with IORT using the Mobetron device.

RESULTS

Forty patients underwent colectomy or proctectomy with IORT. All patients had evidence of local extension to contiguous structures and based on preoperative staging were deemed by the operating surgeon as being likely to have incomplete resection. IORT was selected as an alternative to sacrectomy or exenteration for an expected close margin in 10 patients. Mean survival was 35 +/- 26 months, and 1 patient had local recurrence.

CONCLUSIONS

The introduction of IORT has allowed a selective treatment approach to locally advanced primary and recurrent neoplasms, which traditionally would have been deemed unresectable. Using IORT, extended resections may be avoided in selected high-risk patients with low risk of local recurrence and minimal morbidity.

Patterns of locoregional recurrence after surgery and radiotherapy or chemoradiation for rectal cancer

PURPOSE

To identify patterns of locoregional recurrence in patients treated with surgery and preoperative or postoperative radiotherapy or chemoradiation for rectal cancer.

METHODS AND MATERIALS

Between November 1989 and October 2001, 554 patients with rectal cancer were treated with surgery and preoperative (85%) or postoperative (15%) radiotherapy, with 95% receiving concurrent chemotherapy. Among these patients, 46 had locoregional recurrence as the first site of failure. Computed tomography images showing the site of recurrence and radiotherapy simulation films were available for 36 of the 46 patients. Computed tomography images were used to identify the sites of recurrence and correlate the sites to radiotherapy fields in these 36 patients.

RESULTS

The estimated 5-year locoregional control rate was 91%. The 36 patients in the study had locoregional recurrences at 43 sites. There were 28 (65%) in-field, 7 (16%) marginal, and 8 (19%) out-of-field recurrences. Among the in-field recurrences, 15 (56%) occurred in the low pelvis, 6 (22%) in the presacral region, 4 (15%) in the mid-pelvis, and 2 (7%) in the high pelvis. Clinical T stage, pathologic T stage, and pathologic N stage were significantly associated with the risk of in-field locoregional recurrence. The median survival after locoregional recurrence was 24.6 months.

CONCLUSIONS

Patients treated with surgery and radiotherapy or chemoradiation for rectal cancer had a low risk of locoregional recurrence, with the majority of recurrences occurring within the radiation field. Because 78% of in-field recurrences occur in the low pelvic and presacral regions, consideration should be given to including the low pelvic and presacral regions in the radiotherapy boost field, especially in patients at high risk of recurrence.