Radiotherapy for oligometastatic cancer: a survey among radiation oncologists of Lombardy (AIRO-Lombardy), Italy.

AIMS: To evaluate the use of radiotherapy (RT) for oligometastatic cancer (OMC) among radiation oncologists in Lombardy, Italy. METHODS AND STUDY DESIGN: A survey with 12 items regarding data of 2016 was sent to all 34 Lombardy RT centers. The survey included six general items and six specific items regarding patient/disease/treatment characteristics. RESULTS: Thirteen centers answered the survey (38%). All centers responded to general items and 12 centers submitted patient/disease/treatment data. General items The majority of centers (8/13) consider OMC if metastases number is less than 5. The most commonly prescribed dose/fraction is 5-10 Gy (8/13) using schedules of 3-5 fractions (11/13). Patient data items A total of 15.681 patients were treated in 2016 with external beam RT in 12 responding centers, and 1.087 patients were treated for OMC (7%). Primary tumor included lung, prostate, breast, colorectal and other malignancies in 33%, 21%, 12%, 9% and 25% of all OMC patients, respectively. Brain, lymph node, lung, bone, liver and others were the most common treated sites (24%, 24%, 22%, 17%, 8% and 5%, respectively). One and more than one metastasis were treated in 75 and 25% of patients, respectively. The vast majority of patients (95%) were treated with image-guided intensity-modulated RT or stereotactic RT. CONCLUSIONS: Seven percent of all RT patients in Lombardy are treated for OMC. Extreme hypofractionation and high-precision RT are commonly employed. The initiative of multicenter and multidisciplinary collaboration has been undertaken in order to prepare the platform for prospective and/or observational studies in OMC.

Navigating resistance to ALK inhibitors in the lorlatinib era: a comprehensive perspective on NSCLC.

INTRODUCTION: The emergence of anaplastic lymphoma kinase (ALK) rearrangements in non-small cell lung cancer (NSCLC) has revolutionized targeted therapy. This dynamic landscape, featuring novel ALK inhibitors and combination therapies, necessitates a profound understanding of resistance mechanisms for effective treatment strategies. Recognizing two primary categories - on-target and off-target resistance - underscores the need for comprehensive assessment. AREAS COVERED: This review delves into the intricacies of resistance to ALK inhibitors, exploring complexities in identification and management. Molecular testing, pivotal for early detection and accurate diagnosis, forms the foundation for patient stratification and resistance management. The literature search methodology involved comprehensive exploration of Pubmed and Embase. The multifaceted perspective encompasses new therapeutic horizons, ongoing clinical trials, and their clinical implications post the recent approval of lorlatinib. EXPERT OPINION: Our expert opinion encapsulates the critical importance of understanding resistance mechanisms in the context of ALK inhibitors for shaping successful treatment approaches. With a focus on molecular testing and comprehensive assessment, this review contributes valuable insights to the evolving landscape of NSCLC therapy.

Deep inspiration breath-hold technique guided by an opto- electronic system for extracranial stereotactic treatments.

The purpose of this work was to evaluate the intrapatient tumor position reproducibility in a deep inspiration breath-hold (DIBH) technique based on two infrared optical tracking systems, ExacTrac and ELITETM, in stereotactic treatment of lung and liver lesions. After a feasibility study, the technique was applied to 15 patients. Each patient, provided with a real-time visual feedback of external optical marker displacements, underwent a full DIBH, a free-breathing (FB), and three consecutive DIBH CT-scans centered on the lesion to evaluate the tumor position reproducibility. The mean reproducibility of tumor position during repeated DIBH was 0.5 ± 0.3 mm in laterolateral (LL), 1.0 ± 0.9 mm in anteroposterior (AP), and 1.4 ± 0.9 mm in craniocaudal (CC) direction for lung lesions, and 1.0 ± 0.6 mm in LL, 1.1 ± 0.5 mm in AP, and 1.2 ± 0.4 mm in CC direction for liver lesions. Intra- and interbreath-hold reproducibility during treatment, as determined by optical markers displacements, was below 1 mm and 3 mm, respectively, in all directions for all patients. Optically-guided DIBH technique provides a simple noninvasive method to minimize breathing motion for collaborative patients. For each patient, it is important to ensure that the tumor position is reproducible with respect to the external markers configuration.

Impact of inter-observer variability on first axillary level dosimetry in breast cancer radiotherapy: An AIRO multi-institutional study.

This study quantified the incidental dose to the first axillary level (L1) in locoregional treatment plan for breast cancer. Eighteen radiotherapy centres contoured L1-L4 on three different patients (P1,2,3), created the L2-L4 planning target volume (single centre planning target volume, SC-PTV) and elaborated a locoregional treatment plan. The L2-L4 gold standard clinical target volume (CTV) along with the gold standard L1 contour (GS-L1) were created by an expert consensus. The SC-PTV was then replaced by the GS-PTV and the incidental dose to GS-L1 was measured. Dosimetric data were analysed with Kruskal-Wallis test. Plans were intensity modulated radiotherapy (IMRT)-based. P3 with 90° arm setup had statistically significant higher L1 dose across the board than P1 and P2, with the mean dose (Dmean) reaching clinical significance. Dmean of P1 and P2 was consistent with the literature (77.4% and 74.7%, respectively). The incidental dose depended mostly on L1 proportion included in the breast fields, underlining the importance of the setup, even in case of IMRT.

Almost one year of COVID-19 pandemic: how radiotherapy centers have counteracted its impact on cancer treatment in Lombardy, Italy. CODRAL/AIRO-L study.

Lombardy has represented the Italian and European epicenter of the coronavirus disease 2019 (COVID-19) pandemic. Although most clinical efforts within hospitals were diverted towards the care of virally infected patients, therapies for patients with cancer, including radiotherapy (RT), have continued. During both the first and second pandemic waves, several national and regional organizations provided Italian and Lombardian RT departments with detailed guidelines aimed at ensuring safe treatments during the pandemic. The spread of infection among patients and personnel was limited by adopting strict measures, including triage procedures, interpersonal distance, and adequate implementation of personal protective equipment (PPE). Screening procedures addressed to both the healthcare workforce and patients, such as periodic nasopharyngeal swabs, have allowed the early identification of asymptomatic or pauci-symptomatic COVID-19 cases, thus reducing the spread of the infection. Prevention of infection was deemed of paramount importance to protect both patients and personnel and to ensure the availability of a minimum number of staff members to maintain clinical activity. The choice of treating COVID-19-positive patients has represented a matter of debate, and the risk of oncologic progression has been weighted against the risk of infection of personnel and other patients. Such risk was minimized by creating dedicated paths, reserving time slots, applying intensified cleaning procedures, and supplying personnel and staff with appropriate PPE. Remote working of research staff, medical physicists, and, in some cases, radiation oncologists has prevented overcrowding of shared spaces, reducing infection spread.

External validation of a composite bio-humoral index in anal cancer patients undergoing concurrent chemoradiation.

BACKGROUND AND PURPOSE: A prognostic scoring system based on laboratory inflammation parameters, [Hemo-Eosinophils-Inflammation (HEI) index], including baseline hemoglobin level, the systemic inflammatory index and eosinophil count was recently proposed in patients with squamous cell carcinoma of the anus (ASCC). HEI was shown to discriminate disease-free (DFS) and overall (OS) survival in ASCC patients treated with concurrent chemoradiation (CRT). We tested the accuracy of the model on a multicentric cohort for external validation. MATERIALS AND METHODS: Patients treated with CRT were enrolled. The Kaplan-Meier curves for DFS and OS based on HEI risk group were calculated and the log-rank test was used. Cox proportional hazards models were used to assess the prognostic factors for DFS and OS. The exponential of the regression coefficients provided an estimate of the hazard ratio (HR). For model discrimination, we determined Harrell's C-index, Gönen & Heller K Index and the explained variation on the log relative hazard scale. RESULTS: A total of 877 patients was available. Proportional hazards were adjusted for age, gender, tumor-stage, and chemotherapy. Two-year DFS was 77 %(95 %CI:72.0-82.4) and 88.3 %(95 %CI:84.8-92.0 %) in the HEI high- and low- risk groups. Two-year OS was 87.8 %(95 %CI:83.7-92.0) and 94.2 %(95 %CI:91.5-97). Multivariate Cox proportional hazards model showed a HR = 2.02(95 %CI:1.25-3.26; p = 0.004) for the HEI high-risk group with respect to OS and a HR = 1.53(95 %CI:1.04-2.24; p = 0.029) for DFS. Harrel C-indexes were 0.68 and 0.66 in the validation dataset, for OS and DFS. Gonen-Heller K indexes were 0.67 and 0.71, respectively. CONCLUSION: The HEI index proved to be a prognosticator in ASCC patients treated with CRT. Model discrimination in the external validation cohort was acceptable.

Radiotherapy with Intensity-Modulated (IMRT) Techniques in the Treatment of Anal Carcinoma (RAINSTORM): A Multicenter Study on Behalf of AIRO (Italian Association of Radiotherapy and Clinical Oncology) Gastrointestinal Study Group.

A multi-institutional retrospective study was conducted to evaluate the pattern of care and clinical outcomes of anal cancer patients treated with intensity-modulated radiotherapy (IMRT) techniques. In a cohort of 987 patients, the clinical complete response (CR) rate (beyond 6 months) was 90.6%. The 3-year local control (LC) rate was 85.8% (95% CI: 84.4-87.2), and the 3-year colostomy-free survival (CFS) rate was 77.9% (95% CI: 76.1-79.8). Three-year progression-free survival (PFS) and overall survival (OS) rates were 80.2% and 88.1% (95% CI: 78.8-89.4) (95% CI: 78.5-81.9), respectively. Histological grade 3 and nodal involvement were associated with lower CR (p = 0.030 and p = 0.004, respectively). A statistically significant association was found between advanced stage and nodal involvement, and LC, CFS, PFS, OS and event-free survival (EFS). Overall treatment time (OTT) ≥45 days showed a trend for a lower PFS (p = 0.050) and was significantly associated with lower EFS (p = 0.030) and histological grade 3 with a lower LC (p = 0.025). No statistically significant association was found between total dose, dose/fraction and/or boost modality and clinical outcomes. This analysis reports excellent clinical results and a mild toxicity profile, confirming IMRT techniques as standard of care for the curative treatment of anal cancer patients. Lymph node involvement and histological grade have been confirmed as the most important negative prognostic factors.

Geometric contour variation in clinical target volume of axillary lymph nodes in breast cancer radiotherapy: an AIRO multi-institutional study.

OBJECTIVES: To determine interobserver variability in axillary nodal contouring in breast cancer (BC) radiotherapy (RT) by comparing the clinical target volume of participating single centres (SC-CTV) with a gold-standard CTV (GS-CTV). METHODS: The GS-CTV of three patients (P1, P2, P3) with increasing complexity was created in DICOM format from the median contour of axillary CTVs drawn by BC experts, validated using the simultaneous truth and performance-level estimation and peer-reviewed. GS-CTVs were compared with the correspondent SC-CTVs drawn by radiation oncologists, using validated metrics and a total score (TS) integrating all of them. RESULTS: Eighteen RT centres participated in the study. Comparative analyses revealed that, on average, the SC-CTVs were smaller than GS-CTV for P1 and P2 (by -29.25% and -27.83%, respectively) and larger for P3 (by +12.53%). The mean Jaccard index was greater for P1 and P2 compared to P3, but the overlap extent value was around 0.50 or less. Regarding nodal levels, L4 showed the highest concordance with the GS. In the intra-patient comparison, L2 and L3 achieved lower TS than L4. Nodal levels showed discrepancy with GS, which was not statistically significant for P1, and negligible for P2, while P3 had the worst agreement. DICE similarity coefficient did not exceed the minimum threshold for agreement of 0.70 in all the measurements. CONCLUSIONS: Substantial differences were observed between SC- and GS-CTV, especially for P3 with altered arm setup. L2 and L3 were the most critical levels. The study highlighted these key points to address. ADVANCES IN KNOWLEDGE: The present study compares, by means of validated geometric indexes, manual segmentations of axillary lymph nodes in breast cancer from different observers and different institutions made on radiotherapy planning CT images. Assessing such variability is of paramount importance, as geometric uncertainties might lead to incorrect dosimetry and compromise oncological outcome.

COVID-19 outbreak and cancer radiotherapy disruption in Italy: Survey endorsed by the Italian Association of Radiotherapy and Clinical Oncology (AIRO).

Italy experienced one of the world's deadliest COVID-19 outbreaks and healthcare systems had to instantly reorganise activity. The Italian Radiation Oncology Departments adapted numerous solutions to minimize the disruptions. Information technologies, treatment prioritization and implementation of hypofractionation and protection procedures allowed balancing between cancer patient care and patient/healthcare workers safety.

Back to (new) normality-A CODRAL/AIRO-L survey on cancer radiotherapy in Lombardy during Italian COVID-19 phase 2.

BACKGROUND: Italy experienced one of the world's severest COVID-19 outbreak, with Lombardy being the most afflicted region. However, the imposed safety measures allowed to flatten the epidemic curve and hence to ease the restrictions and inaugurate, on the 4th of May 2020, the Italian phase (P) 2 of the pandemic. The present survey study, endorsed by CODRAL and AIRO-L, aimed to assess how radiotherapy (RT) departments in Lombardy have dealt with the recovery. MATERIALS AND METHODS: A questionnaire dealing with the management of pandemic was developed online and sent to all CODRAL Directors on the 10th of June 2020. Answers were collected in full anonymity one week after. RESULTS: All the 33 contacted RT facilities (100%) responded to the survey. Despite the scale of the pandemic, during P1 14 (42.4%) centres managed to safely continue the activity (≤ 10% reduction). During P2, 10 (30.3%) centres fully recovered and 14 (42.4%) reported an increase. Nonetheless, 6 (18.2%) declared no changes and, interestingly, 3 (9.1%) reduced activities. Overall, 21 centres (63.6%) reported suspected or positive cases within healthcare workforce since the beginning of the pandemic. Staff units were quarantined in 19 (57.6%) and 6 (18.2%) centres throughout P1 and P2, respectively. In the two phases, about two thirds centres registered positive or suspected cases amongst patients. CONCLUSION: The study revealed a particular attention to anti-contagion measures and a return to normal or even higher clinical workload in most RT centres in Lombardy, necessary to carry out current and previously deferred treatments.

Benefits of six degrees of freedom for optically driven patient set-up correction in SBRT.

To quantify the advantages of a 6 degrees of freedom (dof) versus the conventional 3- or 4-dof correction modality for stereotactic body radiation therapy (SBRT) treatments. Eighty-five patients were fitted with 5-7 infra-red passive markers for optical localization. Data, acquired during the treatment, were analyzed retrospectively to simulate and evaluate the best approach for correcting patient misalignments. After the implementation of each correction, the new position of the target (tumor's center of mass) was estimated by means of a dedicated stereotactic algorithm. The Euclidean distance between the corrected and the planned location of target point was calculated and compared to the initial mismatching. Initial and after correction median+/-quartile displacements affecting external control points were 3.74+/-2.55 mm (initial), 2.45+/-0.91 mm (3-dof), 2.37+/-0.95 mm (4-dof), and 2.03+/-1.47 mm (6-dof). The benefit of a six-parameter adjustment was particularly evident when evaluating the results relative to the target position before and after the re-alignment. In this context, the Euclidean distance between the planned and the current target point turned to 0.82+/-1.12 mm (median+/-quartile values) after the roto-translation versus the initial displacement of 2.98+/-2.32 mm. No statistical improvements were found after 3- and 4-dof correction (2.73+/-1.22 mm and 2.60+/-1.31 mm, respectively). Angular errors were 0.09+/-0.93 degrees (mean+/-std). Pitch rotation in abdomen site showed the most relevant deviation, being -0.46+/-1.27 degrees with a peak value of 5.46 degrees . Translational misalignments were -0.68+/-2.60 mm (mean+/-std) with the maximum value of 12 mm along the cranio-caudal direction. We conclude that positioning system platforms featuring 6-dof are preferred for high precision radiation therapy. Data are in line with previous results relative to other sites and represent a relevant record in the framework of SBRT.

Three-times daily radiotherapy after chemotherapy in stage III non-small cell lung cancer. Single-institution prospective study.

AIM: A prospective study for stage IIIA-B nonsmall cell lung cancer (NSCLC), with three-times daily (3td) radiotherapy (RT), after induction chemotherapy (iCT), with or without surgery. PATIENTS AND METHODS: Induction cisplatin and gemcitabine chemotherapy was delivered. Surgery and postoperative (post-op) radiotherapy were planned for responsive stage IIIA patients; definitive irradiation was performed in unresectable IIIA and IIIB patients. Doses of 54.4 and 64.6 Gy were delivered for the post-op and definitive treatments, respectively. RESULTS: Out of 52 patients (pts), 37 received 3tdRT as definitive (18 pts) or post-op treatment (19 pts). Overall, the failures were similar between post-op and definitive 3tdRT (78.9% vs. 77.8%). In the post-op treatment, metastases and local failures were 52.6% and 10.5%, respectively and in the definitive radiotherapy, the incidence was similar (local 33.3% vs. systemic 44.4%). The five-year overall survival (OS) was 25% for the post-op and 21% for the definitive patients (p = 0.87). CONCLUSION: Three-times daily postoperative radiotherapy did not improve the outcome in NSCLC, but for unresectable patients, this approach may have a role in selected cases.

Lymph node metastases of Merkel cell carcinoma from unknown primary site: report of three cases.

Merkel cell carcinoma (MCC) is an uncommon aggressive neuroendocrine skin carcinoma. It usually affects sun-exposed skin of white elderly people. MCC is characterized by a high incidence of early locoregional relapse and distant metastases. Because of its rarity and the resulting lack of prospective randomized trials, data regarding the optimal treatment of MCC are limited. Despite aggressive multimodality treatment, the prognosis of patients bearing MCC is often poor. We report three cases of lymph node metastases of MCC with unknown primary sites. Two patients died 17 and 28 months after diagnosis due to brain and pancreatic metastases, respectively, without evidence of cutaneous disease. The third patient is alive and free of tumor at 16 months from the diagnosis. After an accurate diagnosis of lymph node metastases from MCC, the absence of a primary tumor at complete initial evaluation and during adequate follow-up can confirm this particular clinical scenario. The prognosis seems to be analogous to that of cases with similar disease stage (lymph node involvement) but a known primary site.

Equipment, staffing, and provision of radiotherapy in Lombardy, Italy: Results of three surveys performed between 2012 and 2016.

INTRODUCTION:: Several efforts are being implemented at the European level to measure provision of up-to-date radiation treatments across the continent. METHODS:: A snapshot survey involving all radiation oncology centers within Lombardy, Italy, was performed in 2012 and repeated in 2014 and 2016, in cooperation with regional governmental officers. Centers were asked to provide detailed information concerning all individual patients being treated on the index day, and to report data on available local resources. RESULTS:: We observed an increase in the number of centers and of megavoltage units (MVU) (from 76 to 87, i.e., 8.7 MVU per million inhabitants in 2016). Mean number of MVU per center was 2.5. Average age of MVU increased from 5.3 to 7.5 years and patients on the waiting list also increased. Conformal 3D radiotherapy (RT) treatments decreased from 56% to 42% and were progressively replaced by intensity-modulated RT treatments (from 39% to 49%). Waiting times were overall satisfactory. Radiation oncologists treated on average 152 and radiation therapists 100 RT courses per year. Average reimbursement per course was €4,879 (range €2,476-€8,014). CONCLUSIONS:: The methodology of snapshot survey proved feasible and provided valuable information about radiation oncology provision and accessibility in Lombardy.

Comparison between drug-eluting stents and beta-radiation for the treatment of diffuse in-stent restenosis: clinical and angiographic outcomes.

BACKGROUND: Initial reports on drug-eluting stents (DES) for the treatment for in-stent restenosis (ISR) show very good outcomes. Nevertheless, few data are available on direct comparison with intracoronary brachytherapy (IBT). The aim of this study was to compare brachytherapy and DES in treatment of diffuse ISR. METHODS: One hundred forty-one consecutive patients with diffuse ISR were treated with IBT (68 patients; beta (90Sr/90Y) emitters) or with DES (73 patients; 32 with sirolimus-eluting and 41 with paclitaxel-eluting stents). Angiographic and clinical follow-up was scheduled within 9 months. RESULTS: The first 74 lesions were treated with IBT (group 1) and the latter 74 with DES (group 2). The two groups were well matched for clinical/angiographic characteristics. At follow-up, restenosis rates were 37.8% (28/74) in IBT group and 14.9% (11/74) in DES group (P = .0028). A diffuse pattern of recurrence was more frequent after IBT (20/74 vs 6/74, P = .005). A worse outcome after IBT was associated with the "edge effect," accounting for most failures. Recurrence within the original restenotic stent was similar in both groups (12.9% vs 14.9% in groups 1 and 2 respectively, P = .8). CONCLUSIONS: Drug-eluting stents are more effective than IBT with beta-irradiation in reducing recurrence rates after treatment of diffuse ISR. In case of failure, the pattern of restenosis is more benign after treatment with DES.

3D optoelectronic analysis of interfractional patient setup variability in frameless extracranial stereotactic radiotherapy.

PURPOSE: To investigate size and frequency of interfractional patient setup variability in hypofractionated stereotactic extracranial radiotherapy. METHODS AND MATERIALS: Infrared optical 3D tracking of surface markers was applied to quantify setup variability on 51 patients. Isocenter position repeatability was assessed by means of frameless anatomic calibration and was compared with portal image evaluation. Specific data analysis allowed for compensation of patients' breathing movements and for separation of the effects of operator-dependent misalignments and respiration-induced displacements. Effects of patient position (supine vs. prone) and treatment table configuration were investigated. RESULTS: Patient positioning assisted by the optical tracking device allowed reducing displacements of surface control points within the 3-mm range. Errors in isocenter localization were in the range of a few millimeters. This was in agreement with the portal image evaluation. Breathing motion introduced appreciable errors, which increased control points and isocenter 3D variability. This effect was significantly higher than those related to other investigated factors. CONCLUSIONS: The role of infrared optical tracking devices for patient positioning is assessed on a large patient population. Their use in the frame of high-precision radiotherapy is emphasized by the application of related methodologies for breathing phase detection and frameless isocenter localization.

Modulation of epidermal growth factor receptor status by chemotherapy in patients with locally advanced non-small-cell lung cancer is rare.

PURPOSE: To determine whether epidermal growth factor receptor (EGFR) expression in non-small-cell lung cancer (NSCLC) is modulated by chemotherapy and to assess the agreement of EGFR status between mediastinal nodes and the primary tumor after chemotherapy. PATIENTS AND METHODS: Patients with NSCLC stage IIIa/b pN2/3 confirmed by mediastinoscopy or mediastinostomy were treated with at least three cycles of chemotherapy before undergoing surgery. EGFR expression was evaluated on mediastinal nodes at the time of initial diagnosis and on both the primary tumor and residual metastatic nodes after treatment. RESULTS: EGFR expression determined on 138 of 164 patients who underwent mediastinoscopy or mediastinostomy was 0 (22 patients), 1+ (27 patients), 2+ (28 patients), and 3+ (61 patients). Fifty-four patients of 164 received chemotherapy followed by surgery. Of the 89 of 138 patients with EGFR score of 2+/3+ at the time of diagnosis, 34 patients underwent surgery after induction chemotherapy. None changed to zero EGFR immunoreactivity, with 29 patients (88%) maintaining a score of 2+/3+. Of the 22 of 138 patients with no EGFR expression at the time of diagnosis, six underwent surgical resection after induction chemotherapy. Of these six patients, four changed their EGFR expression from an EGFR score of 0 to 2+/3+. After treatment, the agreement of EGFR status between tumor and nodes in the subgroup of patients with EGFR score 2+/3+ was 89% to 92%. CONCLUSION: Our data suggest a very good agreement of EGFR status before and after chemotherapy in EGFR-positive NSCLC. Induction chemotherapy can induce EGFR expression in occasional EGFR-negative tumors.

Urinary bladder preservation for muscle-invasive bladder cancer: a survey among radiation oncologists of Lombardy, Italy.

AIMS AND BACKGROUND: Bladder preservation is a treatment option in muscle-invasive bladder carcinoma. The most investigated approach is a trimodality schedule including maximum transurethral resection of bladder tumor (TURBT) followed by chemoradiotherapy. Our aim was to evaluate the use of bladder preservation by radiation oncologists of the Lombardy region in Italy. METHODS AND STUDY DESIGN: A survey with 13 items regarding data of 2012 was sent to all 32 radiotherapy centers within the collaboration between the Lombardy Oncological Network and the Lombardy Section of the Italian Society of Oncological Radiotherapy. RESULTS: Thirteen centers (41%) answered the survey; the presented data come from 11 active centers. In these centers, 11,748 patients were treated with external-beam radiotherapy in 2012, 100 of whom having bladder cancer (0.9%). 74/100 patients received radiotherapy as palliative treatment for T, N or M lesions. A further 9 and 5 patients received radiotherapy for oligometastatic disease (ablative doses to small volumes) and postoperatively, respectively. Bladder preservation was performed in 12 cases and included trimodality and other strategies (mainly TURBT followed by radiotherapy). A multidisciplinary urology tumor board met regularly in 5 of 11 centers. All responders declared their interest in the Lombardy multicenter collaboration on bladder preservation. CONCLUSIONS: Our survey showed that bladder preservation is rarely used in Lombardy despite the availability of the latest radiotherapy technologies and the presence of an urology tumor board in half of the centers. The initiative of multicenter and multidisciplinary collaboration was undertaken to prepare the platform for bladder preservation as a treatment option in selected patients.

Dosimetric effects within target and organs at risk of interfractional patient mispositioning in left breast cancer radiotherapy.

PURPOSE: To investigate the effects of interfraction setup uncertainties on the dose distribution within the clinical target volume (CTV) and the organs at risk (OAR) of left-sided breast cancer patients undergoing external radiotherapy. METHODS AND MATERIALS: Interfractional setup errors were assessed by measuring surface control points displacements during 89 irradiation sessions in 4 patients, by means of opto-electronic localization. The measured position deviations were fed back to the treatment planning system for the evaluation of the corresponding dosimetric effects within CTV and OARs (lung, heart). RESULTS: Results revealed errors above 5 mm on some of the control points, but corresponding volumetric variations were on average below 2% for both the CTV within the 95-105% dose range and the OARs receiving more than 50% and 90% of the prescribed dose. A specific sensitivity to the setup errors was found as a function of the treatment plan design, leading to isolated cases exhibiting volumetric variations of CTV and OARs exceeding 2%. CONCLUSIONS: This study confirms the potential increase of treatment quality provided by the systematic patient position verification and highlights the role of opto-electronic position detection systems for the real-time check of patient setup errors and the evaluation of the corresponding dosimetric consequences, as a way to achieve consistent dose delivery.