Is it safe to defer prostate cancer treatment? Assessing the impact of surgical delay on the risk of pathological upstaging after robot-assisted radical prostatectomy

INTRODUCTION

We sought to investigate whether surgical delay may be associated with pathological upstaging in patients treated with robot assisted radical prostatectomy (RARP) for localized and locally advanced prostate cancer (PCa).

MATERIALS AND METHODS

Consecutive firstly-diagnosed PCa patients starting from March 2020 have been enrolled. All the patients were categorized according to EAU risk categories for PCa risk. Uni- and multivariate analysis were fitted to explore clinical and surgical predictors of pathological upstaging to locally advanced disease (pT3/pT4 - pN1 disease).

RESULTS

Overall 2017 patients entered the study. Median age at surgery was 68 (IQR 63-73) years. Overall low risk, intermediate risk, localized high risk and locally advanced disease were recorded in 368 (18.2 %), 1071 (53.1 %), 388 (19.2 %) and 190 (9.4 %), respectively. Median time from to diagnosis to treatment was 51 (IQR 29-70) days. Time to surgery was 56 (IQR 32-75), 52 (IQR 30-70), 45 (IQR 24-60) and 41 (IQR 22-57) days for localized low, intermediate and high risk and locally advanced disease, respectively. Considering 1827 patients with localized PCa, at multivariate analysis ISUP grade group ≥4 on prostate biopsy (HR: 1.30; 95 % CI 1.07-1.86; p = 0.02) and surgical delay only in localized high-risk disease (HR: 1.02; 95 % CI 1.01-1.54; p = 0.02) were confirmed as independent predictors of pathological upstaging to pT3-T4/pN1 disease at final histopathological examination.

CONCLUSIONS

In localized high-risk disease surgical delay could be associated with a higher risk of adverse pathologic findings.

Radiotherapy of Orbital and Ocular Adnexa Lymphoma: Literature Review and University of Catania Experience

Orbital and ocular adnexa lymphomas are rare neoplasms confined to the orbital region. The prognosis is generally favorable, with a high proportion of localized disease, indolent clinical course, prolonged disease-free intervals, and low lymphoma-related mortality rate. We report our experience on eleven patients with confirmed histological diagnosis of lymphoma stage IE-IIE, treated between 2010 and 2021 with radiotherapy alone or in association with chemotherapy or immunotherapy. Eight patients were treated with primary radiotherapy only, while three received previous systemic treatments. Six patients were treated with Proton beam therapy (PBT), and five with external beam radiotherapy (EBRT). The five-year local control rate was 98%; only one patient developed an out-of-field recurrence. We also conducted a comprehensive literature review using electronic databases (PubMed, EMBASE, and Cochrane Library). Articles were selected based on their pertinence to treatment of the ocular and adnexal lymphoma focusing on radiotherapy techniques (electron beam radiotherapy, photon beam radiotherapy, or proton beam radiotherapy), treatment total dose, fractionation schedule, early and late radio-induced toxicities, and patient's clinical outcome. Radiotherapy is an effective treatment option for orbital lymphoma, especially as standard treatment in the early stage of orbital lymphoma, with excellent local control rate and low rates of toxicity.

Redo Partial Nephrectomy for Local Recurrence After Previous Nephron-sparing Surgery. Surgical Insights and Oncologic Results from a High-volume Robotic Center

Background

The role of redo partial nephrectomy (PN) for recurrent renal cell carcinoma (RCC) is still overlooked.

Objective

To report our experience of salvage PN for local recurrence after previous nephron-sparing surgery (NSS).

Design setting and participants

We prospectively gathered data from patients treated with robotic redo PN for locally recurrent RCC after previous NSS from January 2017 to January 2023. The type of surgical resection technique was assigned to the pathologic specimen according to the surface-intermediate-base (SIB) score.

Surgical procedure

Redo PN was performed by using the Si Da Vinci robotic platform.

Measurements

Operative time, warm ischemia time, and intra- and postoperative complications were recorded. The severity of postoperative complications and tumor stage were evaluated.

Results and limitations

Overall, 26 patients entered the study. The median clinical diameter was 3.5 (interquartile range [IQR] 2.2-4.9) cm and the median Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score was 8 (IQR 7-9). In 14 (53.8%) cases, recurrence was at the level of previous tumor resection bed. The median operative time was 177 (IQR 148-200) min, and hilar clamping was performed in 14 (53.8%) cases with a median warm ischemia time of 16 (14.5-22) min. Pure enucleation (SIB score 0-1), hybrid enucleation (SIB score 2), and pure enucleoresection (SIB score 3) were recorded in 13 (50%), eight (30.8%), and five (19.2%) cases, respectively. The totality of recurrent RCC far from previous tumor resection bed received a SIB score of 0-1, while in 57.1% and 35.8% of recurrent RCC on previous tumor resection a hybrid enucleation and a pure enucleoresection were performed, respectively. At a median follow-up of 37 (IQR 16-45) mo, five (19%) patients experienced disease recurrence, being local and systemic in three (11.5%) and two (7.7%) patients, respectively.

Conclusions

Our study highlights the feasibility and safety of redo PN for the treatment of locally recurrent RCCs after NSS, either on previous tumor resection bed or elsewhere in the kidney.

Patient summary

Robotic redo partial nephrectomy is a challenging procedure. The surgeon needs to tailor the surgical strategy and tumor resection technique case by case, given the heterogeneity of clinical scenarios and the need to achieve maximal functional preservation while ensuring oncologic efficacy.

Predictors of early catheter replacement after HoLEP. Results from a high-volume laser center

INTRODUCTION

The aim of the study was to investigate clinical and surgical factors associated with early catheter replacement in patients treated with Holmium Laser Enucleation of the Prostate (HoLEP).

MATERIALS AND METHODS

Data of patients treated with HoLEP at our Institution by a single surgeon from March 2017 to January 2021 were collected. Preoperative variables, including non-invasive uroflowmetry and abdominal ultrasonography (US), were recorded. Bladder wall modifications (BWM) at preoperative US were defined as the presence of single or multiple bladder diverticula or bladder wall thickening 5 mm. Clinical symptoms were assessed using validated questionnaires. Only events occurred within the first week after catheter removal were considered.

RESULTS

Overall, 305 patients were included, of which 46 (15.1%) experienced early catheter replacement. Maintenance of anticoagulants/antiplatelets (AC/AP) therapy at surgery (p=0.001), indwelling urinary catheter (p=0.02) and the presence of BWM (p=0.001) were more frequently reported in patients needing postoperative re-catheterization. Intraoperative complications (p=0.02) and median lasing time (p=0.02) were significantly higher in this group. At univariate analysis, indwelling urinary catheter (p=0.02), BWM (p=0.01), ongoing AC/AP therapy (p=0.01) and intraoperative complications (p=0.01) were significantly associated with early catheter replacement. At multivariate analysis, indwelling urinary catheter (OR: 1.28; p=0.02), BWM (OR: 2.87; p=0.001), and AC/AP therapy (OR: 2.21; p=0.01) were confirmed as independent predictors of catheter replacement.

CONCLUSIONS

In our experience the presence of indwelling urinary catheter before surgery, BWM and the maintenance of AC/AP therapy were shown to be independent predictors of early catheter replacement after HoLEP.

Assessing the Performance of 18F-FDG PET/CT in Bladder Cancer: A Narrative Review of Current Evidence

INTRODUCTION

Lymph node (LN) involvement is a crucial determinant of prognosis for patients with bladder cancer, and an accurate staging is of utmost importance to better identify timely and appropriate therapeutic strategies. To improve the accuracy of LN detection, as an alternative to traditional methods such as CT or MRI, 18F-FDG PET/CT has been increasingly used. 18F-FDG PET/CT is also used in post-treatment restaging after neoadjuvant chemotherapy. The aim of this narrative literature review is to provide an overview of the current evidence on the use of 18F-FDG PET/CT in the diagnosis, staging, and restaging of bladder cancer, with a particular focus on its sensitivity and specificity for the detection of LN metastasis. We aim to provide clinicians with a better understanding of 18F-FDG PET/CT's potential benefits and limitations in clinical practice.

MATERIALS AND METHODS

We designed a narrative review starting from a wide search in the PubMed/MEDLINE and Embase databases, selecting full-text English articles that have examined the sensibility and specificity of PET/CT for nodal staging or restaging after neoadjuvant therapy in patients with bladder cancer. The extracted data were analyzed and synthesized using a narrative synthesis approach. The results are presented in a tabular format, with a summary of the main findings of each study.

RESULTS

Twenty-three studies met the inclusion criteria: fourteen studies evaluated 18F-FDG PET/CT for nodal staging, six studies examined its accuracy for restaging after neoadjuvant therapy, and three studies evaluated both applications. To date, the use of F-18 FDG PET/TC for detection of LN metastasis in bladder cancer is controversial and uncertain: some studies showed low accuracy rates, but over the years other studies have reported evidence of high sensitivity and specificity.

CONCLUSIONS

18F-FDG PET/CT provides important incremental staging and restaging information that can potentially influence clinical management in MIBC patients. Standardization and development of a scoring system are necessary for its wider adoption. Well-designed randomized controlled trials in larger populations are necessary to provide consistent recommendations and consolidate the role of 18F-FDG PET/CT in the management of bladder cancer patients.

Holmium laser enucleation of the prostate (HoLEP) is safe and effective in patients with high comorbidity burden

INTRODUCTION

We assessed the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) in patients with high comorbidity burden.

MATERIALS AND METHODS

Data from patients treated with HoLEP at our academic referral center from March 2017 to January 2021 were prospectively collected. Patients were divided according to their CCI (Charlson Comorbidity Index). Perioperative surgical data and 3-month functional outcomes were collected.

RESULTS

Out of 305 patients included, 107 (35.1%) and 198 (64.9%) were classified as CCI ≥ 3 and < 3, respectively. The groups were comparable in terms of baseline prostate size, symptoms severity, post-void residue and Qmax. The amount of energy delivered during HoLEP (141.3 vs. 118.0 KJ, p=0.01) and lasing time (38 vs 31 minutes, p=0.01) were significantly higher in patients with CCI ≥ 3. However, median enucleation, morcellation and overall surgical time were comparable between the two groups (all p>0.05). Intraoperative complications rate (9.3% vs. 9.5%, p=0.77), median time to catheter removal and hospital stay were comparable between the two cohorts. Similarly, early (30 days) and delayed (>30 days) surgical complications rates were not significantly different between the two groups. At 3-month follow up, functional outcomes using validated questionnaires did not differ between the two groups (all p>0.05).

CONCLUSIONS

HoLEP represents a safe and effective treatment option for BPH also in patients with high comorbidity burden.

The Abundance of Tumor-Infiltrating CD8+ Tissue Resident Memory T Lymphocytes Correlates with Patient Survival in Glioblastoma

Glial tumors alone account for 40% of all CNS tumors and present a low survival rate. The tumor microenvironment is a critical regulator of tumor progression and therapeutic effectiveness in glioma. Growing evidence from numerous studies of human solid tumor-infiltrating CD8⁺ T cells indicates that tissue-resident memory T cells (TRM) represent a substantial subpopulation of tumor-infiltrating lymphocytes (TILs). Although it is reported that some types of cancer patients with high immune infiltration tend to have better outcomes than patients with low immune infiltration, it seems this does not happen in gliomas. This study aimed to characterize TRMs cells in the glioma tumor microenvironment to identify their potential predictive and prognostic role and the possible therapeutic applications. Fluorescence activated cell sorting (FACS) analysis and immunofluorescence staining highlighted a statistically significant increase in CD8⁺ TRM cells (CD103⁺ and CD69⁺ CD8⁺ T cells) in gliomas compared to control samples (meningioma). In-silico analysis of a dataset of n = 153 stage IV glioma patients confirmed our data. Moreover, the gene expression analysis showed an increase in the expression of TRM-related genes in tumor tissues compared to normal tissues. This analysis also highlighted the positive correlation between genes associated with CD8⁺ TRM and TILs, indicating that CD8⁺ TRMs cells are present among the infiltrating T cells. Finally, high expression of Integrin subunit alpha E (ITGAE), the gene coding for the integrin CD103, and high CD8⁺ TILs abundance were associated with more prolonged survival, whereas high ITGAE expression but low CD8⁺ TILs abundance were associated with lower survival.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part II: treatment indications and complications

Therapy of uveal melanoma aims to preserve the eye and its function and to avoid metastatic dissemination. The treatment choice is difficult and must keep into account several factors; the therapeutic strategy of uveal melanoma should therefore be personalized, sometimes requiring to combine different treatment techniques. Nowadays globe-sparing radiotherapy techniques are often preferred to enucleation. Plaque brachytherapy, the most commonly used eye-preserving therapy, is suitable for small- and medium-sized uveal melanomas. Proton beam radiotherapy is indicated for tumours with noticeable size, challenging shape and location, but is more expensive and less available than brachytherapy. Enucleation is currently restricted to advanced tumours, uveal melanomas with orbital or optic nerve involvement, blind and painful eyes because of treatment-related complications (neovascular glaucoma, chronic inflammatory processes). The effect of proton beam therapy on neoplastic tissue is related to direct cytotoxic action of the radiations, impairment of neoplastic vascular supply and immunologic response. Complications after radiotherapy are frequent and numerous and mainly related to tumour thickness, radiation dose and distance between the tumour and optic nerve. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present second section, we discuss the therapeutic management of uveal melanoma, describing the main ocular-conserving radiotherapic techniques. We subsequently present an overview of the effects of radiations on neoplastic tissue. Lastly, we review ocular complications following radiotherapy that should be evaluated by radiologists during follow-up MRI examinations.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part I: MR imaging with pathologic correlation and technical considerations

Uveal melanoma is a malignant neoplasm that derives from pigmented melanocytes of the uvea and involves, in order of decreasing prevalence, the choroid, ciliary body and iris. Its prognosis is related to histopathologic and genetic features, tumor size and location, extraocular extension. The diagnosis is fundamentally based on clinical evaluation (ophthalmoscopy, biomicroscopy) and ultrasonography. MRI is useful in case of untransparent lens or subretinal effusion. Moreover, MRI has a significant role to confirm the diagnosis, in the evaluation of the local extent of the disease with implications for treatment planning, and in the follow-up after radiotherapy treatment. Uveal melanoma can show different morphologic features (lentiform, dome or mushroom shape) and often determines retinal detachment. MR appearance of uveal melanoma mainly depends on the melanin content. Uveal melanoma typically displays high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Nevertheless, imaging appearance may be variable based on the degree of pigmentation and the presence of areas of necrosis or cavitation. Differential diagnosis includes other uveal lesions. The radiologists and in particular MRI play a significant role in the clinical management of uveal melanoma. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present first section we summarize the MR anatomy of the eye and describe ophthalmological and radiological imaging techniques to diagnose uveal melanomas, with emphasis on the role of MR imaging. Additionally, we review MR imaging appearance of uveal melanomas.

Clinical Application of Proton Beams in the Treatment of Uveal Melanoma: The First Therapies Carried Out in Italy and Preliminary Results (Catana Project)

Background

The first Italian proton therapy facility was realized in Catania, at the INFN-LNS. With its energy (62 MeV proton beam), it is ideal for the treatment of shallow tumors like those of the ocular region: uveal melanoma, first of all (the most common primary intraocular malignancy of adults) and other less frequent lesions like choroidal hemangioma, conjunctiva melanoma, and eyelid tumors.

Material and methods

The first patient was enrolled in February 2002, and to date 30 patients have been treated. All patients had a localized uveal melanoma, with no systemic metastases, and had specific indications for proton beam radiation therapy: lesions between 5–25 mm basal diameter, not exceeding 15 mm thickness, absence of total retinal detachment or glaucoma. According to the tumor dimensions, 2 patients had a small lesion or T1 (6%), 3 had a medium-sized lesion or T2 (10%), 14 had a large lesion or T3 (47%), and 11 had an extra-large lesion or T3 (37%); no patient had extrascleral invasion or T4 of the TNM-AJCC Staging System. In most cases, the tumor infiltrated only the choroid (14 patients, 47%) or the choroid plus the ciliary body (14 patients, 47%). We also treated a primitive iris melanoma, without diffusion to the ciliary body. The target volume was defined as the tumor plus a safety margin of 2.5 mm, laterally and antero-posteriorly; this margin was increased to 3 mm if ciliary body involvement was present. The treatment was carried out in 4 fractions on 4 consecutive days to a total dose of 54.5 Gy (single fraction 13.6 Gy), which corresponds to 60 CGE (Cobalt Gray Equivalent; single fraction 15 CGE), because the relative biological effectiveness is 1.1.

Results

The first follow-up is planned at 6–8 months after the end of the treatment, and our clinical end points are local control (defined as cessation of growth or tumor shrinkage), eye retention, and maintenance of a good visual function. At the time of this writing, we had preliminary results from 13 patients. Nine patients showed tumor shrinkage (69%), 3 a substantially stable dimension (23%), but almost all patients presented an increased ultrasound reflectivity (a surrogate for tumor control).

Discussion and conclusions

The literature data show that charged particle therapy has allowed an optimal local control in the treatment of uveal melanomas (about 96% in the different series, superior to that obtained with plaquetherapy [between 83% and 92%]), a metastatic rate slightly better than enucleation reports, and a survival rate of almost 90% at 5 years. Our preliminary results show a tumor response in almost all cases, with no major acute or subacute side effects. We thus plan to continue with our treatment procedures and our dose prescription.

Combined taxane-based chemotherapy and intensity-modulated radiotherapy with simultaneous integrated boost for gastroesophageal junction adenocarcinoma

We describe our experience, gained over the past 3 years, in the treatment of gastroesophageal junction adenocarcinoma, whose incidence has been increasing in recent years. In our series, we present the results to a follow-up of about 2 years for a total of 18 patients, treated with a particularly intensive combination treatment. It consists of neoadjuvant induction chemotherapy with the protocol docetaxel-cisplatin-5-fluorouracil for four cycles, before a concomitant chemoradiotherapy treatment. During combined phase, patients received an intensity-modulated radiotherapy and a weekly cisplatin. We will present the data to a long follow-up time and we will discuss the literature, the integration with thoracoabdominal surgery and other specific issues of this pathology.

Single-institution experience of intensity-modulated radiotherapy for malignant pleural mesothelioma at University of Catania

AIM

The multimodal approach to malignant pleural mesothelioma is gradually becoming the standard of care for this disease in patients with good performance status. Materials & methods: We report our experience concerning eight cases treated with the use of static step-and-shoot intensity-modulated radiotherapy to the whole pleural cavity, in patients already undergoing surgical and/or antiblastic therapy. Results & conclusion: Results at a median follow-up of 16 months showed a median survival from the initial treatment of 29 months, with lung toxicity of grade II reported only in two patients.

Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach

The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described.

Role, timing and technique of radiotherapy in pediatric pleuropulmonary synovial sarcoma

The management of pediatric thoracic synovial sarcoma remains a matter of debate in clinical oncology, especially as regard to the local control of the disease. Surgery remains the gold standard, while the role and timing of radiotherapy is still controversial. We report a 14-year-old male, who has not received proper treatment at the time of diagnosis and initial management. Intensity-modulated irradiation was performed only at relapse, as a salvage treatment and, at 10-month follow-up, the young patient was free from relapse, without significant acute and subacute toxicity. We discuss the role and timing of radiotherapy in thoracic synovial sarcoma, a disease in which the need to increase local control should be placed in the foreground.

Intensity-modulated radiotherapy for relapsed malignant pleural mesothelioma

The use of novel radiotherapy techniques is widely increasing, allowing clinicians to treat diseases that were previously difficult to treat with radiation therapy. Malignant pleural mesothelioma is a clear example of this clinical challenge. We describe our first experience with intensity-modulated radiotherapy technique which was used to treat a 73-year-old patient with multiple relapsing malignant pleural mesothelioma. Intensity-modulated radiation therapy has allowed to respect the QUANTEC (quantitative analyses of normal tissue effects in the clinic) dose constraints, patient has experienced a 14 months progression-free time, without relevant subacute or late lung toxicity.

Locally advanced rectal cancer: Qualitative and quantitative evaluation of diffusion-weighted MR imaging in the response assessment after neoadjuvant chemo-radiotherapy

PURPOSE

to investigate the added value of qualitative and quantitative evaluation of diffusion weighted (DW) magnetic resonance (MR) imaging in response assessment after neoadjuvant chemo-radiotherapy (CRT) in patients with locally advanced rectal cancer (LARC).

METHODS

31 patients with LARC (stage ≥ T3) were enrolled in the study. All patients underwent conventional MRI and DWI before starting therapy and after neoadjuvant CRT. All patients underwent surgery; pathologic staging represented the reference standard. For qualitative analysis, two radiologists retrospectively reviewed conventional MR images and the combined set of conventional and DW MR images and recorded their confidence level with respect to complete response (ypCR). For quantitative analysis, tumor's apparent diffusion coefficient (ADC) values were measured at each examination. ADC pre-CRT, ADC post-CRT and Δ ADC post-ADC pre of the three groups of response (ypCR, partial response ypPR, stable disease ypSD) were compared. Receiver-operating characteristics (ROC) curve analysis was employed to investigate the discriminatory capability for ypCR, responders (ypCR, ypPR) and ypSD of each measure.

RESULTS

addition of DWI to conventional T2-weighted sequences improved diagnostic performance of MRI in the evaluation of ypCR. A low tumor ADC value in the pre-CRT examination, a high ADC value in the post-CRT examination, a high Δ ADC post-ADC pre [>0.3 (×10(-3) mm(2)/s)] were predictive of ypCR.

CONCLUSIONS

DW sequences improve MR capability to evaluate tumor response to CRT. Nevertheless, no functional MR technique alone seems accurate enough to safely select patients with ypCR.

Addition of bevacizumab (beva) to xeliri/xelox chemoradiotherapy in neoadjuvant setting for patients (pts) with locally advanced rectal cancer (LARC): A feasibility study

14583

Background: Preoperative chemo-radiotherapy in pts with LARC has been extensively evaluated, although no standard treatment has been defined. We planned to add the new anti-VEGF monoclonal antibody bevacizumab in the neoadjuvant setting, in order to evaluate whether the modifications induced in normal and tumor microcirculation and vascularity could increase the treatment toxicity profile and induce relevant complications during the surgery. Methods: From Jul 05 to Sept 06, pts with histologically proven uT3–4 N± or uT2 N+ rectal cancer were treated with capecitabine 1,000 mg/m2 bid on days 1–14 before chemoradiation phase and then 825 mg/m2 bid on days 22–55 plus irinotecan 180 mg/m2 (XELIRI) or oxaliplatin 130 mg/m2 (XELOX) on days 1, 22, 43 in combination with BEVA 5 mg/kg q2w starting on day 1 until the completion of the treatment. Radiotherapy was administered according to our previous study (45 Gy to the whole pelvis, plus 9 Gy as conc. boost to the CTV during the last six fractions). Surgery was carried out 8 weeks after the completion of chemoradiation. Results: Eleven pts (7 male/4 female), ECOG PS 0–1, were enrolled in this study. No patient showed systemic disease at the time of diagnosis. Six pts received XELIRI chemotherapy, 5 pts XELOX. Ten pts completed the planned chemotherapy schedule, one patient discontinued chemotherapy administration after the second irinotecan infusion due to GI grade III toxicity. All eleven pts completed the planned radiation treatment, with a total dose of 54 Gy. Three pts reported moderate hypertension, treated with standard anti-hypertensive drugs, and one had epistaxis, but no one required discontinuation of BEVA Conclusions: The use of BEVA in the neoadjuvant setting of pts with LARC is feasible and safe. In combination with XELIRI/XELOX chemoradiation, BEVA does not increase the treatment toxicity profile, nor provoke any surgical delay or modifications. BEVA in this setting should be further evaluated in larger phase II studies, in order to estimate the rates of clinical and pathologic complete and partial response, compared to XELIRI/XELOX chemoradiation schedules.

No significant financial relationships to disclose.

Neoadjuvant XELOX vs. XELIRI in combination with concomitant boost 3D-conformal radiotherapy in locally advanced rectal cancer (LARC)

3570

Background: While several randomized trials have shown that preoperative chemoradiation reduces local recurrence in LARC, there is no standard chemoradiation schedule. The aim of this study was to compare capecitabine + oxaliplatin (XELOX) vs. capecitabine + irinotecan (XELIRI) in association with high-dose radiotherapy. Methods: Patients (pts) with histologically proven uT3–4 N-/+ or uT2 N+ LARC were randomized to receive capecitabine 1250mg/m2 bid d1–14 before chemoradiation and then 825mg/m2 bid d22–55 plus either oxaliplatin 130mg/m2 d1,22&43 (18 pts) or irinotecan 180mg/m2 d1,22&43 (18 pts). On d22 pts also received radiotherapy administered to the whole pelvis (maximum 45Gy; 1.8Gy/fraction), with a concomitant boost to the CTV (maximum 9Gy; 1.5Gy/fraction) during the last 6d of treatment with a 6h inter-fraction interval. Surgery was carried out 6–8w after chemoradiation by the same surgical team. Results: 36 pts (23M/13F, median age 59 years, ECOG PS 0–1) were enrolled between Jan03 and Jun05. No pt had systemic disease at the time of diagnosis. One pt in the XELIRI group discontinued chemoradiation because of GI toxicity; the other 35 pts (18 XELOX, 17 XELIRI) received 95% and 92% of the planned chemotherapy doses, respectively. The most common adverse event was grade 3/4 diarrhea (6% XELOX, 18% XELIRI). There was no relevant neurotoxicity. 12 pts (67%) on XELOX and 12 pts (71%) on XELIRI had clinical and pathological downstaging. There were no treatment-related deaths. A complete pathological remission was seen in 4 pts (22%) on XELOX and 5 pts (29%) on XELIRI. 25 pts (71%; 13 XELOX, 12 XELIRI) underwent sphincter-saving surgery and 10 pts had Miles abdomino-perineal resection. All pts are alive after a median follow-up of 20 months (range 7–36 months), but 4 (2 in each group) have developed distant metastases. Conclusions: XELOX and XELIRI are feasible and effective, with high efficacy comparable to that observed with other neoadjuvant regimens. XELOX was better tolerated, as diarrhea was seen more frequently in the XELIRI arm. Further studies of these regimens are warranted in this setting.

No significant financial relationships to disclose.

Preliminary investigation on the use of the MOSFET dosimeter in proton beams

Metal Oxide Semiconductor (MOS) device structures can be used to measure ionizing radiation through the mechanism of hole trapping in the oxide layer leading to changing of electrical characteristic of the device. They are a new type of direct reading semiconductor dosimeters. Due to their extremely small physical size, ability to permanently store the accumulated dose, dose-rate independence and their ease of use make them very promising for in vivo dosimetry. They are attractive for dosimetry in small radiation fields used in modern radiation oncology modalities, as conformal radiotherapy, IMRT, stereotactic radiotherapy/radiosurgery and proton therapy. Preliminary results on the use of commercial MOSFET dosimeters (TN-502RD, Thomson & Nielsen Electronics Ltd, Canada) irradiated on therapeutic 62 MeV proton beams are presented. Linearity with absorbed dose, sensibility and energy dependence were investigated. Moreover, the possibility to use of MOSFET dosimeters in order to measure the Output Factors (OF) for very small irradiation fields was verified. The comparison of OF obtained using MOSFETs and other dosimetry systems is reported.

The use of thermoluminescent detectors for measurements of proton dose distribution

The aim of this work was to investigate the use of TLD-100 detectors in the field of relative dosimetry in proton eye facilities. These dosemeters, of different sizes, were used to measure transverse and longitudinal distributions of 62 MeV unmodulated proton beams at INFN-LNS in Catania. Comparison with other detectors, such as ionisation chambers, GAF and radiographic film, is extensively discussed.