Post-Chemoradiation Metastatic, Persistent and Resistant Nodes in Locally Advanced Rectal Cancer: Metrics and Their Impact on Long-Term Outcome

BACKGROUND

The purpose of this study was to evaluate the long-term oncological progression pattern of locally advanced rectal cancer patients with post-neoadjuvant nodal metastatic disease (ypN+) and correlate potential prognostic features associated with proven radiochemoresistant nodal biology.

METHODS

Individual patient data (100 variables) from a 20-year consecutive single-institution multidisciplinary experience (1995-2015), delivering multimodal therapy to rectal cancer patient candidates for radical treatment, including a neoadjuvant component and surgical resection with or without intraoperative radiotherapy followed by optional adjuvant chemotherapy. The ypN+ disease data was registered in the context of initial staging categories post-neoadjuvant T status (ypT).

RESULTS

Data on 487 patients showed histologically confirmed diagnoses of metastatic nodal disease in 108 specimens (ypN+, 22.1). There was a significant age difference (p = 0.009) between the ypN groups: age ≥ 65 was 57.6% in pN0 and 43.5% in ypN+ and patients aged < 65 constituted 42.4% of pN0 and 56.5% of ypN+. According to the clinical stage there were statistically significant differences (p = 0.001) in the categories' distribution: ypN+ patients 10.8% were stage II and 89.2% were stage III. Univariant analysis on outcome variables showed statistically significant differences in overall survival at 7 years (63.8% vs. 55.7%, p = 0.016) disease-free survival (DFS) (78% vs. 53.8%, p = 0.000) and local recurrence-free survival (LRFS) (93.6% vs. 84%, p = 0.002).

CONCLUSIONS

The presence of nodal metastases (ypN+) after neoadjuvant therapy containing long-course pelvic irradiation severely impacts the long-term outcome for patients with locally advanced rectal cancer and correlates with multiple clinical and therapeutic variable metrics. Implementation of local and systemic therapies should be adapted and intensified in relation to the finding of ypN+ category in surgical specimens.

Hospital-based proton therapy implementation during the COVID pandemic: early clinical and research experience in a European academic institution

INTRODUCTION

A rapid deploy of unexpected early impact of the COVID pandemic in Spain was described in 2020. Oncology practice was revised to facilitate decision-making regarding multimodal therapy for prevalent cancer types amenable to multidisciplinary treatment in which the radiotherapy component searched more efficient options in the setting of the COVID-19 pandemic, minimizing the risks to patients whilst aiming to guarantee cancer outcomes.

METHODS

A novel Proton Beam Therapy (PBT), Unit activity was analyzed in the period of March 2020 to March 2021. Institutional urgent, strict and mandatory clinical care standards for early diagnosis and treatment of COVID-19 infection were stablished in the hospital following national health-authorities' recommendations. The temporary trends of patients care and research projects proposals were registered.

RESULTS

3 out of 14 members of the professional staff involved in the PBR intra-hospital process had a positive test for COVID infection. Also, 4 out of 100 patients had positive tests before initiating PBT, and 7 out of 100 developed positive tests along the weekly mandatory special checkup performed during PBT to all patients. An update of clinical performance at the PBT Unit at CUN Madrid in the initial 500 patients treated with PBT in the period from March 2020 to November 2022 registers a distribution of 131 (26%) pediatric patients, 63 (12%) head and neck cancer and central nervous system neoplasms and 123 (24%) re-irradiation indications. In November 2022, the activity reached a plateau in terms of patients under treatment and the impact of COVID pandemic became sporadic and controlled by minor medical actions. At present, the clinical data are consistent with an academic practice prospectively (NCT05151952). Research projects and scientific production was adapted to the pandemic evolution and its influence upon professional time availability. Seven research projects based in public funding were activated in this period and preliminary data on molecular imaging guided proton therapy in brain tumors and post-irradiation patterns of blood biomarkers are reported.

CONCLUSIONS

Hospital-based PBT in European academic institutions was impacted by COVID-19 pandemic, although clinical and research activities were developed and sustained. In the post-pandemic era, the benefits of online learning will shape the future of proton therapy education.

Corrigendum: 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

[This corrects the article DOI: 10.3389/fonc.2022.1037262.].

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.

Current practice in proton therapy delivery in adult cancer patients across Europe

BACKGROUND AND PURPOSE

Major differences exist among proton therapy (PT) centres regarding PT delivery in adult cancer patient. To obtain insight into current practice in Europe, we performed a survey among European PT centres.

MATERIALS AND METHODS

We designed electronic questionnaires for eight tumour sites, focusing on four main topics: 1) indications and patient selection methods; 2) reimbursement; 3) on-going or planned studies, 4) annual number of patients treated with PT.

RESULTS

Of 22 centres, 19 (86%) responded. In total, 4233 adult patients are currently treated across Europe annually, of which 46% consists of patients with central nervous system tumours (CNS), 15% head and neck cancer (HNC), 15% prostate, 9% breast, 5% lung, 5% gastrointestinal, 4% lymphoma, 0.3% gynaecological cancers. CNS are treated in all participating centres (n = 19) using PT, HNC in 16 centres, lymphoma in 10 centres, gastrointestinal in 10 centres, breast in 7 centres, prostate in 6 centres, lung in 6 centres, and gynaecological cancers in 3 centres. Reimbursement is provided by national health care systems for the majority of commonly treated tumour sites. Approximately 74% of centres enrol patients for prospective data registration programs. Phase II-III trials are less frequent, due to reimbursement and funding problems. Reasons for not treating certain tumour types with PT are lack of evidence (30%), reimbursement issues (29%) and/or technical limitations (20%).

CONCLUSION

Across European PT centres, CNS tumours and HNC are the most frequently treated tumour types. Most centres use indication protocols. Lack of evidence for PT and reimbursement issues are the most reported reasons for not treating specific tumour types with PT.

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy

BACKGROUND

The purpose of this study was to investigate the prevalence of ypN+ status according to ypT category in patients with locally advanced rectal cancer treated with chemoradiotherapy and total mesorectal excision, and to assess the impact of ypN+ on disease recurrence and survival by pooled analysis of individual-patient data.

METHODS

Individual-patient data from 10 studies of chemoradiotherapy for rectal cancer were included. Pooled rates of ypN+ disease were calculated with 95 per cent confidence interval for each ypT category. Kaplan-Meier and Cox regression analyses were undertaken to assess influence of ypN status on 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

Data on 1898 patients were included in the study. Median follow-up was 50 (range 0-219) months. The pooled rate of ypN+ disease was 7 per cent for ypT0, 12 per cent for ypT1, 17 per cent for ypT2, 40 per cent for ypT3, and 46 per cent for ypT4 tumours. Patients with ypN+ disease had lower 5-year DFS and OS (46.2 and 63.4 per cent respectively) than patients with ypN0 tumours (74.5 and 83.2 per cent) (P < 0.001). Cox regression analyses showed ypN+ status to be an independent predictor of recurrence and death.

CONCLUSION

Risk of nodal metastases (ypN+) after chemoradiotherapy increases with advancing ypT category and needs to be considered if an organ-preserving strategy is contemplated.

Association of visual and quantitative heterogeneity of 18F-FDG PET images with treatment response in locally advanced rectal cancer: A feasibility study

Background and purpose

Few tools are available to predict tumor response to treatment. This retrospective study assesses visual and automatic heterogeneity from ¹⁸F-FDG PET images as predictors of response in locally advanced rectal cancer.

Methods

This study included 37 LARC patients who underwent an ¹⁸F-FDG PET before their neoadjuvant therapy. One expert segmented the tumor from the PET images. Blinded to the patient´s outcome, two experts established by consensus a visual score for tumor heterogeneity. Metabolic and texture parameters were extracted from the tumor area. Multivariate binary logistic regression with cross-validation was used to estimate the clinical relevance of these features. Area under the ROC Curve (AUC) of each model was evaluated. Histopathological tumor regression grade was the ground-truth.

Results

Standard metabolic parameters could discriminate 50.1% of responders (AUC = 0.685). Visual heterogeneity classification showed correct assessment of the response in 75.4% of the sample (AUC = 0.759). Automatic quantitative evaluation of heterogeneity achieved a similar predictive capacity (73.1%, AUC = 0.815).

Conclusion

A response prediction model in LARC based on tumor heterogeneity (assessed either visually or with automatic texture measurement) shows that texture features may complement the information provided by the metabolic parameters and increase prediction accuracy.

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.

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

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

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

•

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

•

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

•

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

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

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

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

Postoperative Radiation Therapy in Patients with Extracranial Chondrosarcoma: A Joint Study of the French Sarcoma Group and Rare Cancer Network

PURPOSE

Postoperative radiation therapy (poRT) of intracranial/skull base chondrosarcomas (CHSs) is standard treatment. However, consensus is lacking for poRT in extracranial CHS (eCHS) owing to their easier resectability and intrinsic radioresistance. We assessed the practice and efficacy of poRT in eCHS.

METHODS AND MATERIALS

This multicentric retrospective study of the French Sarcoma Group/Rare Cancer Network included patients with eCHS who were operated on between 1985 and 2015. Inverse propensity score weighting (IPTW) was used to minimize poRT allocation biases.

RESULTS

Of 182 patients, 60.4% had bone and 39.6% had soft-tissue eCHS. eCHS were of conventional (31.9%), myxoid (28.6%; 41 extraskeletal, 11 skeletal), mesenchymal (9.9%), or other subtypes. En-bloc surgery with complete resection was performed in 52.6% and poRT in 36.8% of patients (median dose, 54 Gy). Irradiated patients had unfavorable initial characteristics, with higher grade and incomplete resection. Median follow-up time was 61 months. Five-year incidence of local relapse was 10% with poRT versus 21.6% without (P = .050). Using the IPTW method, poRT reduced the local relapse risk (hazard ratio, 0.27; 95% confidence interval, 0.14-0.52; P < .001). Five-year disease-free survival (DFS) was 71.8% with poRT and 64.2% without (P = .680). Using the IPTW method, poRT improved DFS (hazard ratio, 0.51; 95% confidence interval, 0.30-0.85; P = .010). The benefit of poRT on local relapse and DFS was confirmed after exclusion of the extraskeletal subtype. There was no difference in overall survival. Prognostic factors of poorer DFS in multivariate analysis were deeper location, higher grade, incomplete resection, and no poRT.

CONCLUSIONS

poRT should be offered in patients with eCHS and high-grade or incomplete resection, regardless of the histologic subtype.

Intraoperative computed tomography imaging for dose calculation in intraoperative electron radiation therapy: Initial clinical observations

In intraoperative electron radiation therapy (IOERT) the energy of the electron beam is selected under the conventional assumption of water-equivalent tissues at the applicator end. However, the treatment field can deviate from the theoretic flat irradiation surface, thus altering dose profiles. This patient-based study explored the feasibility of acquiring intraoperative computed tomography (CT) studies for calculating three-dimensional dose distributions with two factors not included in the conventional assumption, namely the air gap from the applicator end to the irradiation surface and tissue heterogeneity. In addition, dose distributions under the conventional assumption and from preoperative CT studies (both also updated with intraoperative data) were calculated to explore whether there are other alternatives to intraoperative CT studies that can provide similar dose distributions. The IOERT protocol was modified to incorporate the acquisition of intraoperative CT studies before radiation delivery in six patients. Three studies were not valid to calculate dose distributions due to the presence of metal artefacts. For the remaining three cases, the average gamma pass rates between the doses calculated from intraoperative CT studies and those obtained assuming water-equivalent tissues or from preoperative CT studies were 73.4% and 74.0% respectively. The agreement increased when the air gap was included in the conventional assumption (98.1%) or in the preoperative CT images (98.4%). Therefore, this factor was the one mostly influencing the dose distributions of this study. Our experience has shown that intraoperative CT studies are not recommended when the procedure includes the use of shielding discs or surgical retractors unless metal artefacts are removed. IOERT dose distributions calculated under the conventional assumption or from preoperative CT studies may be inaccurate unless the air gap (which depends on the surface irregularities of the irradiated volume and on the applicator pose) is included in the calculations.

Stereotactic Radiosurgery for the Treatment of Recurrent High-grade Gliomas: Long-term Follow-up

High-grade gliomas (HGG) are the most frequent primary central nervous system tumors; treatment of HCGs includes surgery and post-operative conformal radiotherapy associated with temozolomide (TMZ or procarbazine/lomustine/vincristine [PCV], specifically in patients with anaplastic oligodendrogliomas or anaplastic oligoastrocytomas). However, recurrence is common. Re-irradiation has been utilized in this setting for years and remains a feasible option, although there is always a concern regarding toxicity. Modern high-precision conformal techniques, including stereotactic radiosurgery (SRS), could improve the therapeutic ratio by delivering high biologically equivalent doses while reducing high-dose radiotherapy (RT) to normal brain tissue. In this paper, we present the results obtained after prolonged follow-up in patients who underwent SRS as a treatment for recurrent high-grade gliomas at San Francisco Hospital in Madrid, Spain.

Adjuvant chemoradiation in pancreatic cancer: impact of radiotherapy dose on survival

BACKGROUND

To evaluate the impact of radiation dose on overall survival (OS) in patients treated with adjuvant chemoradiation (CRT) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

A multicenter retrospective analysis on 514 patients with PDAC (T1-4; N0-1; M0) treated with surgical resection with macroscopically negative margins (R0-1) followed by adjuvant CRT was performed. Patients were stratified into 4 groups based on radiotherapy doses (group 1: < 45 Gy, group 2: ≥ 45 and < 50 Gy, group 3: ≥ 50 and < 55 Gy, group 4: ≥ 55 Gy). Adjuvant chemotherapy was prescribed to 141 patients. Survival functions were plotted using the Kaplan-Meier method and compared through the log-rank test.

RESULTS

Median follow-up was 35 months (range: 3-120 months). At univariate analysis, a worse OS was recorded in patients with higher preoperative Ca 19.9 levels (≥ 90 U/ml; p < 0.001), higher tumor grade (G3-4, p = 0.004), R1 resection (p = 0.004), higher pT stage (pT3-4, p = 0.002) and positive nodes (p < 0.001). Furthermore, patients receiving increasing doses of CRT showed a significantly improved OS. In groups 1, 2, 3, and 4, median OS was 13.0 months, 21.0 months, 22.0 months, and 28.0 months, respectively (p = 0.004). The significant impact of higher dose was confirmed by multivariate analysis.

CONCLUSIONS

Increasing doses of CRT seems to favorably impact on OS in adjuvant setting. The conflicting results of randomized trials on adjuvant CRT in PDAC could be due to < 45 Gy dose generally used.

TGFβ Blockade Enhances Radiotherapy Abscopal Efficacy Effects in Combination with Anti-PD1 and Anti-CD137 Immunostimulatory Monoclonal Antibodies

Radiotherapy can be synergistically combined with immunotherapy in mouse models, extending its efficacious effects outside of the irradiated field (abscopal effects). We previously reported that a regimen encompassing local radiotherapy in combination with anti-CD137 plus anti-PD-1 mAbs achieves potent abscopal effects against syngeneic transplanted murine tumors up to a certain tumor size. Knowing that TGFβ expression or activation increases in irradiated tissues, we tested whether TGFβ blockade may further enhance abscopal effects in conjunction with the anti-PD-1 plus anti-CD137 mAb combination. Indeed, TGFβ blockade with 1D11, a TGFβ-neutralizing mAb, markedly enhanced abscopal effects and overall treatment efficacy against subcutaneous tumors of either 4T1 breast cancer cells or large MC38 colorectal tumors. Increases in CD8 T cells infiltrating the nonirradiated lesion were documented upon combined treatment, which intensely expressed Granzyme-B as an indicator of cytotoxic effector capability. Interestingly, tumor tissue but not healthy tissue irradiation results in the presence of higher concentrations of TGFβ in the nonirradiated contralateral tumor that showed smad2/3 phosphorylation increases in infiltrating CD8 T cells. In conclusion, radiotherapy-induced TGFβ hampers abscopal efficacy even upon combination with a potent immunotherapy regimen. Therefore, TGFβ blockade in combination with radioimmunotherapy results in greater efficacy.

Surface scanning for 3D dose calculation in intraoperative electron radiation therapy

Background

Dose calculations in intraoperative electron radiation therapy (IOERT) rely on the conventional assumption of water-equivalent tissues at the applicator end, which defines a flat irradiation surface. However, the shape of the irradiation surface modifies the dose distribution. Our study explores, for the first time, the use of surface scanning methods for three-dimensional dose calculation of IOERT.

Methods

Two different three-dimensional scanning technologies were evaluated in a simulated IOERT scenario: a tracked conoscopic holography sensor (ConoProbe) and a structured-light three-dimensional scanner (Artec). Dose distributions obtained from computed tomography studies of the surgical field (gold standard) were compared with those calculated under the conventional assumption or from pseudo-computed tomography studies based on surfaces.

Results

In the simulated IOERT scenario, the conventional assumption led to an average gamma pass rate of 39.9% for dose values greater than 10% (two configurations, with and without blood in the surgical field). Results improved when considering surfaces in the dose calculation (88.5% for ConoProbe and 92.9% for Artec).

Conclusions

More accurate three-dimensional dose distributions were obtained when considering surfaces in the dose calculation of the simulated surgical field. The structured-light three-dimensional scanner provided the best results in terms of dose distributions. The findings obtained in this specific experimental setup warrant further research on surface scanning in the IOERT context owing to the clinical interest of improving the documentation of the actual IOERT scenario.

Intraoperative Electron Radiation Therapy Combined with External Beam Radiation Therapy after Gross Total Resection in Extremity Soft Tissue Sarcoma: A European Pooled Analysis

INTRODUCTION

We report a pooled analysis evaluating the combination of gross complete limb-sparing surgery, intraoperative electron radiation therapy (IOERT), and external beam radiation therapy (EBRT) in patients with extremity soft tissue sarcoma (STS).

METHODS

Individual data of 259 patients (median follow-up 63 months) with extremity STS from three European expert centers were pooled. Median age was 55 years and median tumor size was 8 cm. Eighty percent of patients presented with primary disease, mainly located in the lower limb (81%). Union for International Cancer Control 7th edition stage at presentation was as follows: stage I: 9%; stage II: 47%; stage III: 39%; stage IV: 5%. Most patients showed high-grade lesions (91%), predominantly liposarcoma (31%). Median IOERT dose was 12 Gy, preceeded (17%) or followed (83%) by EBRT, with a median dose of 45 Gy.

RESULTS

Surgery resulted in R0 resections in 71% of patients and R1 resections in 29% of patients. The 5-year local control (LC) rate was 86%, and significant factors in univariate analysis were disease status and resection margin. Only margin remained significant in multivariate analysis. The 5-year distant control rate was 69%, and significant factors in univariate analysis were histology, grading, resection margin, and metastases prior to/at IOERT. Only grading and metastases remained significant in multivariate analysis. Actuarial 5-year rates of freedom from treatment failure and OS were 61% and 78%, respectively. Significant factors for OS were grading and metastases prior to/at IOERT (univariate, multivariate). Limb preservation and good functional outcome were achieved in 95% and 81% of patients.

CONCLUSIONS

Our pooled analysis confirmed prior reports of encouraging LC and survival, with excellent rates of preserved limb function with this treatment approach. Resection margin remained the most important factor for LC, while grading and metastases prior to/at IOERT mainly predicted survival.

Prognostic Impact of Presurgical CA19-9 Level in Pancreatic Adenocarcinoma: A Pooled Analysis

BACKGROUND: Presurgical carbohydrate antigen 19-9 (CA19-9) level predicts overall survival (OS) in resected pancreatic adenocarcinoma (PaC). The aim of this pooled analysis was to evaluate if presurgical CA19-9 level can also predict local control (LC) and distant metastasis-free survival (DMFS). METHODS: Seven hundred patients with PaC from eight institutions who underwent surgical resection ± adjuvant treatment between 2000 and 2014 were analyzed. Patients were divided based on four presurgical CA19-9 level cutoffs (5, 37, 100, 353 U/ml). Weibull regression model to identify independent predictors of OS on 404 patients with complete information was fitted. RESULTS: Median follow-up was 17 months (range: 2-225 months). Univariate analysis showed a better prognosis in pT1-2, pN0, diameter <30 mm, or grade 1 tumors and in patients undergoing R0 resection, distal pancreatectomy, or adjuvant chemotherapy and with lower CA19-9 levels. Five-year OS, LC, and DMFS were as follows: CA19-9 <5.0: 5.7%, 47.2%, 17.0%; CA19-9 5.1-37.0: 37.9%, 63.3%, 46.0%; CA19-9 37.1-100.0: 27.1%, 59.4%, 39.0%; CA19-9 100.1-353.0: 17.4%, 43.4%, 26.7%; CA19-9 >353.1: 10.9%, 50.2%, and 23.4%, respectively. At multivariate analysis, CA19-9 >100 and <353 level (P=.002), CA19-9 ≥353.1 (P<.001) level, G3 tumor (P=.002), and tumor diameter >30 mm (P<.001) correlated with worse OS. Patients treated with postoperative chemoradiation doses >50.0 Gy showed improved OS (P<.001). CONCLUSION: Presurgical CA19-9 predicts both OS and pattern of failure. Therefore, CA19-9 should be included in predictive models in order to customize treatments based on prognostic factors. Moreover, future studies should stratify patients according to presurgical CA19-9 level.

The value of oxaliplatin in the systemic treatment of locally advanced rectal cancer

BACKGROUND

To evaluate, in a context of innovative multidisciplinary clinical practice, the efficacy of oxaliplatin in adjuvant administration (chemotherapy, CT) in relation to the total administered dose, in terms of prognosis with other clinical and therapeutic factors, in the heterogeneous model of locally advanced rectal cancer (LARC), which is characterized by a risk pattern of dominant systemic progression.

METHODS

Observational-analytical, retrospective, unicentric, non-randomized study of two cohorts of patients receiving FOLFOX-4 induction CT in neoadjuvancy, radiochemotherapy and surgery, differing in that one cohort did not receive any adjuvant post-surgical treatment and the other one received adjuvant CT with FOLFOX-4 cycles. A total of 212 patients from the Radiotherapy Oncology Service at the University Hospital Gregorio Marañon were studied: the neoadjuvant CT treatment group with oxaliplatin consisted of 110 patients and adjuvant CT treatment group with oxaliplatin consisted of 102 patients. The median follow-up time for the whole study population was 72 months (6 years).

RESULTS

The sociodemographic, clinical and diagnostic characteristics were very similar in both cohorts of patients, but with a pattern of therapeutic selection towards elements of adversity in pathological post-neoadjuvant staging. The dose of oxaliplatin in adjuvance (postoperative) superior to 6 cycles was positively associated with the locoregional control (LRC) at 5 years (P=0.012) and with the overall survival (OS) (P=0.048) at 5 years. In the responders to neoadjuvance with oxaliplatin [patients with tumor regression grade (TRG 3-4)], the dose of oxaliplatin greater than 5 cycles in adjuvance (postoperative) was positively associated with OS (P=0.06). And the dose of oxaliplatin in the range of 4-5 cycles in adjuvance (postoperative) was positively associated with distant metastasis-free survival (DMFS) and disease-free survival (DFS) in the cohort of responding patients (P=0.015 and 0.004, respectively).

CONCLUSIONS

The contribution of adjuvant oxaliplatin in the oncological evolution shows a favorable effect of LRC, DMFS, DFS and OS in the subgroups of patients that exhibit elements of response to neoadjuvant oxaliplatin (categories TRG 3-4, and pN0, downstaging T, downstaging N). Therefore, this neoadjuvant response profile with oxaliplatin, measured with highly reliable methodology (validated microscopic pathological response scales), defines a population of oxaliplatin-sensitive patients who benefits significantly from the administration of adjuvant oxaliplatin in sufficient cumulative doses (more of 5 cycles).

[Radiotherapy for local disease in metastatic prostate cancer.]

OBJECTIVES

We elaborate the bases and rationale for the application of multimodal extended treatment including local radiotherapy in patients with oligometastatic prostate cancer (omPCa). We performed a bibliographic review on the state of the art in this field and propose a therapeutic strategy that incorporates ablative radiotherapy of the primary tumor +/- oligometastatic lesions.

METHODS

We performed a comprehensive literature review consulting different sources that include data bases (Pubmed/Medline), and international treatment guidelines ((NCCN, NCI, EUA). Search criteria: Locally advanced prostate cancer, oligometastatic, disseminated and radiotherapy, ablative or stereotactic radiotherapy (SBRT).

RESULTS

The most accepted definition for oligometastatic prostate cancer or oligotopic prostatic neoplasia is when we recognize at least 3 non-visceral metastatic lesions in an extrapelvic location. Whole body MRI and PET scan (Choline/PSMA) are non conventional useful tests for staging in the workup for oligometastatic disease. From a clinical point of view, omPCa behaves as an intermediate entity between locally advanced and disseminated or multimetastatic prostate cancer. Androgen deprivation therapy (ADT) represents the base of treatment for castration sensitive PCa. To date there is no biological marker/genetic sign identified that differentiate aggressiveness profiles in omPca. Most evidence on the use of radiotherapy for this entity comes from retrospective studies, showing a benefit in control and prevention of local symptoms. To date, the survival benefit derived from the application of local treatment to the primary tumor with demonstrable metastatic disease is uncertain, and it has not been shown in the available randomized prospective clinical trials.

CONCLUSIONS

Primary tumor radiotherapy in omPca positively influences local control and prevention of local symptoms progression. The level of evidence to recommend prostatic radiotherapy as a therapeutic variable with impact on survival on omPca is limited (Level 2B-3 Category). Research lines in omPca deserve the inclusion of a multimodal systemic treatment including ADT, ablative radiotherapy for the tumor and consolidation radiotherapy in metastatic distant lesions.

Intraoperative irradiation: precision medicine for quality cancer control promotion

Intraoperative irradiation was implemented 4 decades ago, pioneering the efforts to improve precision in local cancer therapy by combining real-time surgical exploration/resection with high single dose radiotherapy (Gunderson et al., Intraoperative irradiation: techniques and results, 2011). Clinical and technical developments have led to very precise radiation dose deposit. The ability to deliver a very precise dose of radiation is an essential element of contemporary multidisciplinary individualized oncology.

This issue of Radiation Oncology contains a collection of expert review articles and updates with relevant data regarding intraoperative radiotherapy. Technology, physics, biology of single dose and clinical results in a variety of cancer sites and histologies are described and analyzed. The state of the art for advanced cancer care through medical innovation opens a significant opportunity for individualize cancer management across a broad spectrum of clinical practice. The advantage for tailoring diagnostic and treatment decisions in an individualized fashion will translate into precise medical treatment.

Late Radiation and Cardiovascular Adverse Effects After Androgen Deprivation and High-Dose Radiation Therapy in Prostate Cancer: Results From the DART 01/05 Randomized Phase 3 Trial

PURPOSE

To present data on the late toxicity endpoints of a randomized trial (DART 01/05) conducted to determine whether long-term androgen deprivation (LTAD) was superior to short-term AD (STAD) when combined with high-dose radiation therapy (HDRT) in patients with prostate cancer (PCa).

PATIENTS AND METHODS

Between November 2005 and December 2010, 355 eligible men with cT1c-T3aN0M0 PCa and intermediate-risk and high-risk factors (2005 National Comprehensive Cancer Network criteria) were randomized to 4 months of AD combined with HDRT (median dose, 78 Gy) (STAD) or the same treatment followed by 24 months of AD (LTAD). Treatment-related complications were assessed using European Organization for Research and Treatment of Cancer-Radiation Therapy Oncology Group and Common Terminology Criteria for Adverse Events v3.0 scoring schemes. Multivariate analyses for late toxicity were done using the Fine-Gray method.

RESULTS

The 5-year incidence of grade ≥2 rectal and urinary toxicity was 11.1% and 8.2% for LTAD and 7.6% and 7.3% for STAD, respectively. Compared with STAD, LTAD was not significantly associated with a higher risk of late grade ≥2 rectal toxicity (hazard ratio [HR] 1.360, 95% confidence interval [CI] 0.660-2.790, P=.410) or urinary toxicity (HR 1.028, 95% CI 0.495-2.130, P=.940). The multivariate analysis showed that a baseline history of intestinal comorbidity (HR 3.510, 95% CI 1.560-7.930, P=.025) and the rectal volume receiving >60 Gy (Vr60) (HR 1.030, 95% CI 1.001-1.060, P=.043) were the only factors significantly correlated with the risk of late grade ≥2 rectal complications. A history of previous surgical prostate manipulations was significantly associated with a higher risk of grade ≥2 urinary complications (HR 2.427, 95% CI 1.051-5.600, P=.038). Long-term AD (HR 2.090; 95% CI 1.170-3.720, P=.012) and a history of myocardial infarction (HR 2.080; 95% CI 1.130-3.810, P=.018) were significantly correlated with a higher probability of cardiovascular events.

CONCLUSION

Long-term AD did not significantly impact urinary or rectal radiation-induced toxicity, although it was associated with a higher risk of cardiovascular events. Longer follow-up is needed to measure the impact of AD on late morbidity and non-PCa mortality.

Adjuvant radiation therapy in resected high-grade localized skeletal osteosarcomas treated with neoadjuvant chemotherapy: Long-term outcomes

PURPOSE

To assess long-term outcomes and toxicity of adjuvant radiotherapy in the post-surgical management of patients with resected high-grade skeletal osteosarcomas.

METHODS AND MATERIALS

Seventy-two patients with primary resected osteosarcomas underwent adjuvant radiotherapy after neoadjuvant chemotherapy from December 1984 to December 2008. Local control (LC), overall survival (OS) and disease-free survival (DFS) were estimated using Kaplan-Meier methods. For survival outcomes potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model.

RESULTS

After a median follow-up of 174months (range, 33-363months), 10-year LC, DFS, and OS rates were 82%, 58%, and 73%, respectively. In the multivariate analysis only R1 margin status (p=0.02) remained significantly associated with LC. Patients with tumor necrosis <90% (p=0.04) and R1 resection margin (p=0.05) remained at a significantly higher risk of mortality on multivariate analysis. Six patients (8%) developed grade ⩾3 treatment-related chronic toxicity events. No grade 5 toxicities were reported.

CONCLUSIONS

A multimodal radiotherapy-containing approach is a well-tolerated component of treatment for patients with osteosarcomas undergoing programed resection, allowing low toxicity rates while maintaining high local control rates.

Metabolic and molecular relative percentage coreduction in patients with locally advanced rectal cancer treated with neoadjuvant therapy

PURPOSE

Vascular endothelial growth factor receptor-2 (VEGFR-2), epidermal growth factor receptor-1 (EGFR) and cyclooxygenase-2 (COX-2) stimulate key processes involved in tumour progression and are important targets for cancer therapeutics. (18)F-FDG maximum standardized uptake value (SUVmax) on PET/CT is a marker of tumour metabolic activity. The purpose of this study was to measure percentage reductions in SUVmax (∆SUVmax%), VEGFR-2 (∆VEGFR-2%), EGFR (∆EGFR%) and COX-2 (∆COX-2%) in patients with locally advanced rectal cancer (LARC) after preoperative treatment, and to correlate the changes in these markers of response with pathological response in terms of tumour regression grade (TRG) using Rödel's scale and long-term clinical outcome.

METHODS

VEGFR-2, EGFR and COX-2 were measured using a quantitative and qualitative compound immunohistochemistry analysis (immunoreactive score) of the pretreatment endoscopic biopsy and definitive surgical specimens. Composite indexes using ∆SUVmax% and the three molecules were developed to differentiate patients with metabolic and molecular responses from nonresponders. Cox proportional hazards model was used to explore associations between the tumour markers, disease-free survival (DFS) and overall survival (OS).

RESULTS

The analysis included 38 patients with a median follow-up of 86 months (range 5 - 113 months). The ∆VEGFR-2%/∆SUVmax% index correctly identified 13 of 19 pathological responders (TRG 3 and 4) and 17 of 19 nonresponders (TRG 0 - 2) (sensitivity 68 %, specificity 89 %, accuracy 79 %, positive predictive value 87 %, negative predictive value 74 %). In multivariate analysis, only the ∆VEGFR-2%/∆SUVmax% index was associated with DFS (HR 0.11, p = 0.001) and OS (HR 0.15, p = 0.02).

CONCLUSION

In patients with LARC the ∆VEGFR-2%/∆SUVmax% response index is associated with outcome. Determination of the optimal diagnostic cut-off level for this novel biomarker association should be explored. Evaluation in a clinical trial is required to determine whether selected patients could benefit from treatment with a VEGFR-targeted therapeutic agent.

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.

Adjuvant Chemoradiation in Pancreatic Cancer: A Pooled Analysis in Elderly (≥75 years) Patients

AIM

To determine the impact of postoperative chemoradiation (POCR) on overall survival (OS) after resection of pancreatic adenocarcinoma (PAC) in elderly (≥75 years) patients.

MATERIALS AND METHODS

A multi-center retrospective review of 1248 patients who underwent complete resection with macroscopically negative margins (R0-1) for invasive PAC was performed. Exclusion criteria included age <75 years, metastatic or unresectable disease at surgery, macroscopic residual disease (R2), treatment with intraoperative radiotherapy (IORT) and postoperative death.

RESULTS

A total of 98 patients were included in the analysis (males=39.8%, females=60.2%; R1 resections=33.7%; pN1=61.2%); 63 patients received POCR and 26 patients received adjuvant chemotherapy alone. The median follow-up was 25.6 months. The mean age for the entire cohort of patients was 78.1±2.9 (SD) years. No differences were observed between patients receiving or not receiving POCR in terms of age (p=0.081), tumor diameter (p=0.412), rate of R1 resection (p=0.331) and incidence of lymph node-positive disease (p=0.078). The only factor predicting an improved OS was POCR. The median OS was 69.0 months in patients treated by POCR and 23.0 months in patients treated without POCR (p=0.008). Even by Cox multivariate analysis, the only significant predictor of OS was POCR (hazard ratio=0.449; 95% confidence interval=0.212-0.950; p=0.036).

CONCLUSION

The study represents the first comparative approach on POCR in elderly patients after resection of PAC. OS was higher in patients who received POCR. Further analyses are warranted to evaluate the toxicity rate/grade and the impact of POCR on patient quality of life.

Adjuvant chemotherapy in rectal cancer: defining subgroups who may benefit after neoadjuvant chemoradiation and resection: a pooled analysis of 3,313 patients

Recent literature suggests that the benefit of adjuvant chemotherapy (aCT) for rectal cancer patients might depend on the response to neoadjuvant chemoradiation (CRT). Aim was to evaluate whether the effect of aCT in rectal cancer is modified by response to CRT and to identify which patients benefit from aCT after CRT, by means of a pooled analysis of individual patient data from 13 datasets. Patients were categorized into three groups: pCR (ypT0N0), ypT1-2 tumour and ypT3-4 tumour. Hazard ratios (HR) for the effect of aCT were derived from multivariable Cox regression analyses. Primary outcome measure was recurrence-free survival (RFS). One thousand seven hundred and twenty three (1723) (52%) of 3,313 included patients received aCT. Eight hundred and ninety eight (898) patients had a pCR, 966 had a ypT1-2 tumour and 1,302 had a ypT3-4 tumour. For 122 patients response, category was missing and 25 patients had ypT0N+. Median follow-up for all patients was 51 (0-219) months. HR for RFS with 95% CI for patients treated with aCT were 1.25(0.68-2.29), 0.58(0.37-0.89) and 0.83(0.66-1.10) for patients with pCR, ypT1-2 and ypT3-4 tumours, respectively. The effect of aCT in rectal cancer patients treated with CRT differs between subgroups. Patients with a pCR after CRT may not benefit from aCT, whereas patients with residual tumour had superior outcomes when aCT was administered. The test for interaction did not reach statistical significance, but the results support further investigation of a more individualized approach to administer aCT after CRT and surgery based on pathologic staging.

Feasibility assessment of the interactive use of a Monte Carlo algorithm in treatment planning for intraoperative electron radiation therapy

This work analysed the feasibility of using a fast, customized Monte Carlo (MC) method to perform accurate computation of dose distributions during pre- and intraplanning of intraoperative electron radiation therapy (IOERT) procedures. The MC method that was implemented, which has been integrated into a specific innovative simulation and planning tool, is able to simulate the fate of thousands of particles per second, and it was the aim of this work to determine the level of interactivity that could be achieved. The planning workflow enabled calibration of the imaging and treatment equipment, as well as manipulation of the surgical frame and insertion of the protection shields around the organs at risk and other beam modifiers. In this way, the multidisciplinary team involved in IOERT has all the tools necessary to perform complex MC dosage simulations adapted to their equipment in an efficient and transparent way. To assess the accuracy and reliability of this MC technique, dose distributions for a monoenergetic source were compared with those obtained using a general-purpose software package used widely in medical physics applications. Once accuracy of the underlying simulator was confirmed, a clinical accelerator was modelled and experimental measurements in water were conducted. A comparison was made with the output from the simulator to identify the conditions under which accurate dose estimations could be obtained in less than 3 min, which is the threshold imposed to allow for interactive use of the tool in treatment planning. Finally, a clinically relevant scenario, namely early-stage breast cancer treatment, was simulated with pre- and intraoperative volumes to verify that it was feasible to use the MC tool intraoperatively and to adjust dose delivery based on the simulation output, without compromising accuracy. The workflow provided a satisfactory model of the treatment head and the imaging system, enabling proper configuration of the treatment planning system and providing good accuracy in the dosage simulation.

Failure mode and effect analysis oriented to risk-reduction interventions in intraoperative electron radiation therapy: the specific impact of patient transportation, automation, and treatment planning availability

BACKGROUND AND PURPOSE

Industrial companies use failure mode and effect analysis (FMEA) to improve quality. Our objective was to describe an FMEA and subsequent interventions for an automated intraoperative electron radiotherapy (IOERT) procedure with computed tomography simulation, pre-planning, and a fixed conventional linear accelerator.

MATERIAL AND METHODS

A process map, an FMEA, and a fault tree analysis are reported. The equipment considered was the radiance treatment planning system (TPS), the Elekta Precise linac, and TN-502RDM-H metal-oxide-semiconductor-field-effect transistor in vivo dosimeters. Computerized order-entry and treatment-automation were also analyzed.

RESULTS

Fifty-seven potential modes and effects were identified and classified into 'treatment cancellation' and 'delivering an unintended dose'. They were graded from 'inconvenience' or 'suboptimal treatment' to 'total cancellation' or 'potentially wrong' or 'very wrong administered dose', although these latter effects were never experienced. Risk priority numbers (RPNs) ranged from 3 to 324 and totaled 4804. After interventions such as double checking, interlocking, automation, and structural changes the final total RPN was reduced to 1320.

CONCLUSIONS

FMEA is crucial for prioritizing risk-reduction interventions. In a semi-surgical procedure like IOERT double checking has the potential to reduce risk and improve quality. Interlocks and automation should also be implemented to increase the safety of the procedure.

Role of radiotherapy in the chemotherapy-containing multidisciplinary management of patients with resected pancreatic adenocarcinoma

BACKGROUND

To analyze prognostic factors associated with long-term outcomes in patients with resected pancreatic cancer treated with chemotherapy (CT) and surgery with or without external beam radiotherapy (EBRT).

PATIENTS AND METHODS

From January 1995 to December 2012, 95 patients with adenocarcinoma of the pancreas and locoregional disease [clinical stage IB-IIA (n = 45; 47%), IIB-IIIC (n = 50; 53%)] were treated with curative resection [R0 (n = 52; 55%), R1 (n = 43, 45%)] and CT with (n = 60; 63%) or without (n = 35; 37%) EBRT (45-50.4 Gy). Additionally, 29 patients (48%) also received a pre-anastomosis IOERT boost (applicator diameter size, 7-10 cm; dose, 10-15 Gy; beam energy, 9-18 MeV).

RESULTS

With a median follow-up of 17.2 months (range, 1-182), 2-year overall survival (OS), disease-free survival (DFS), and locoregional control were 28, 20, and 53%, respectively. Univariate analyses showed that IIB-IIIC stage (HR, 2.23; p = 0.04), R1 margin resection status (HR, 2.09; p = 0.04), no vascular resection (HR, 0.42; p = 0.02), and not receiving external beam radiotherapy (HR, 2.70; p = 0.004) were associated with locoregional recurrence. In the multivariate analysis, only R1 margin resection status (HR, 2.63; p = 0.009) and not receiving EBRT (HR, 2.91; p = 0.002) retained significance with regard to locoregional recurrence. We observed no difference in toxicity between patients treated with or without EBRT (p = 0.44). Overall treatment mortality was 3%. No long-term treatment-related death occurred.

CONCLUSIONS

Although adjuvant CT is still the standard of care for resected pancreatic tumors, OS remains modest owing to the high risk of distant metastases. Locoregional treatment needs to be tested in the context of more efficient systemic therapy.

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.

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.

Interval between neoadjuvant treatment and definitive surgery in locally advanced rectal cancer: impact on response and oncologic outcomes

PURPOSE

The optimal waiting period between neoadjuvant treatment completion and surgery in locally advanced rectal cancer (LARC) is controversial. The specific purpose of this study was to evaluate the effect of prolonging this interval on the pathologic response, postoperative morbidity, and long-term oncologic outcomes.

METHODS

Retrospective data analysis is reported from LARC patients who had been treated with chemoradiation followed by surgery and intra-operative radiotherapy, between February 1995 and December 2012. In total, two groups were studied, according to the time elapsed between neoadjuvant treatment and surgery: conventional interval (CI; <6 weeks) and delayed interval (DI; ≥6 weeks). Clinicopathological data related to tumor response, postoperative morbidity, and oncologic outcomes were compared.

RESULTS

This study included 335 consecutive LARC patients. There was a higher proportion of patients with clinical staging nodal involvement (cN+) in the DI group (76.6 vs. 64.1 %; p = 0.01). The pathologic complete response (pCR) was not significantly different among groups (8.8 vs. 12.1 %; p = 0.34). Longer intervals did not affect complication incidence or severity or hospital admission length. Certain postneoadjuvant tumor effect parameters were significantly increased in the DI group, including N-downstaging and T-downsizing. After a median follow-up of 71 months, patients in the DI group presented with superior 5-year overall survival (OS) (55.9 vs. 70.4 %, p = 0.014); however, no statistically significant differences were observed in 5-year disease-free survival (DFS) or 5-year local control (LC) (69.9 vs. 74.9 %, p = 0.223; 90.4 vs. 94.5 %, p = 0.123, respectively).

CONCLUSIONS

A modest surgical interval delay (≥6 weeks) did not increase postoperative complications and was identified as a favorable prognostic factor for OS, although no differences were observed in pCR, LC, or DFS. Innovative multidisciplinary strategies incorporating further time extension of the surgical interval can be safely explored.