Development of Predictive Models for the Response of Vestibular Schwannoma Treated with Cyberknife®: A Feasibility Study Based on Radiomics and Machine Learning.

PURPOSE: to predict vestibular schwannoma (VS) response to radiosurgery by applying machine learning (ML) algorithms on radiomic features extracted from pre-treatment magnetic resonance (MR) images. METHODS: patients with VS treated with radiosurgery in two Centers from 2004 to 2016 were retrospectively evaluated. Brain T1-weighted contrast-enhanced MR images were acquired before and at 24 and 36 months after treatment. Clinical and treatment data were collected contextually. Treatment responses were assessed considering the VS volume variation based on pre- and post-radiosurgery MR images at both time points. Tumors were semi-automatically segmented and radiomic features were extracted. Four ML algorithms (Random Forest, Support Vector Machine, Neural Network, and extreme Gradient Boosting) were trained and tested for treatment response (i.e., increased or non-increased tumor volume) using nested cross-validation. For training, feature selection was performed using the Least Absolute Shrinkage and Selection Operator, and the selected features were used as input to separately build the four ML classification algorithms. To overcome class imbalance during training, Synthetic Minority Oversampling Technique was used. Finally, trained models were tested on the corresponding held out set of patients to evaluate balanced accuracy, sensitivity, and specificity. RESULTS: 108 patients treated with Cyberknife® were retrieved; an increased tumor volume was observed at 24 months in 12 patients, and at 36 months in another group of 12 patients. The Neural Network was the best predictive algorithm for response at 24 (balanced accuracy 73% ± 18%, specificity 85% ± 12%, sensitivity 60% ± 42%) and 36 months (balanced accuracy 65% ± 12%, specificity 83% ± 9%, sensitivity 47% ± 27%). CONCLUSIONS: radiomics may predict VS response to radiosurgery avoiding long-term follow-up as well as unnecessary treatment.

Multisession radiosurgery for grade 2 (WHO), high risk meningiomas. A phase II clinical trial.

PURPOSE: Patients suffering from recurrent and residual grade 2 (WHO) meningiomas after subtotal excision should be considered as high-risk groups with an uncertain prognosis. Adjuvant radiotherapy seems to be the best approach to reduce disease progression. The primary aim of this phase II explorative, monocentric, single arm study was to evaluate the safety of adjuvant multisession radiosurgery (mRS) in this group of patients; the efficacy in terms of tumour local control was the secondary endpoint. METHODS: Patients recruited from April 2017 to May 2019 were over 18 years old, had a histologically-documented intracranial recurrent or residual Grade 2 meningioma (WHO 2016) and a KPS > 70. Patients with NF2, concomitant neoplasm or pregnancy were excluded. Descriptive statistics were provided for categorical variables. Progression free survival (PFS) was modelled using the Kaplan-Meier method. RESULTS: Twenty-four patients were enrolled. All 24 patients underwent mRS: twenty-two patients received 28 Gy in 4 fractions, 2 patients received 24 Gy in 4 Treatment related adverse events (CTCAE 4.3) were limited to grade 2 in 1 patient (4.1%). At a median follow-up of 28 months, 8 patients (33.3%) had disease progression, either out-of-field or infield, compared with the planning target volume. Considering both infield and out-of-field progressions, 3-year PFS was 47% (95% confidence interval, CI, 22-69%); considering only the infield ones, 3-year PFS was 86% (95% CI 55-96%), and local control at last follow-up was 92%. CONCLUSION: mRS provides good local control of the tumour volume (TV) and is associated with a low rate of toxicity. These results call for further investigation to confirm favourable outcomes in patients with high-risk meningioma. TRIAL INFORMATION: NCT05081908, October 18, 2021, retrospectively registered.

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.

Evaluation of Mediators Associated with the Inflammatory Response in Prostate Cancer Patients Undergoing Radiotherapy.

A recent "hot topic" in prostate cancer radiotherapy is the observed association between acute/late rectal toxicity and the presence of abdominal surgery before radiotherapy. The exact mechanism is unclear. Our working hypothesis was that a previous surgery may influence plasma level of inflammatory molecules and this might result in enhanced radiosensitivity. We here present results on the feasibility of monitoring the expression of inflammatory molecules during radiotherapy. Plasma levels of a panel of soluble mediators associated with the inflammatory response were measured in prostate cancer patients undergoing radical radiotherapy. We measured 3 cytokines (IL-1b, IL-6, and TNF alpha), 2 chemokines (CCL2 and CXCL8), and the long pentraxin PTX3. 20 patients were enrolled in this feasibility evaluation. All patients were treated with IMRT at 78 Gy. 3/20 patients reported grade 2 acute rectal toxicity, while 4/20 were scored as grade 2 late toxicity. CCL2 was the most interesting marker showing significant increase during and after radiotherapy. CCL2 levels at radiotherapy end could be modelled using linear regression including basal CCL2, age, surgery, hypertension, and use of anticoagulants. The 4 patients with late toxicity had CCL2 values at radiotherapy end above the median value. This trial is registered with ISRCTN64979094.

Patient-reported intestinal toxicity from whole pelvis intensity-modulated radiotherapy: First quantification of bowel dose-volume effects.

BACKGROUND AND PURPOSE: Intestinal toxicity is commonly experienced during whole-pelvis intensity-modulated radiotherapy (WPRT) for prostate cancer. The aim of the current study was to assess bowel dose-volume relationships for acute patient-reported intestinal symptoms of patients treated with WPRT for prostate cancer. MATERIALS AND METHODS: Complete data of 206 patients were available; the median dose to pelvic nodes was 51.8Gy (range 50.4-54.4, 1.7-2Gy/fr). Intestinal symptoms were assessed as changes in the Inflammatory Bowel Disease Questionnaire scores relative to the Bowel Domain (IBDQ-B) between baseline and radiotherapy mid-point/end. The 25th percentiles of the most severe worsening from baseline (ΔIBDQ-B) were set as end-points. The impact of bowel loops and sigmoid colon dose-volume/surface parameters as well as selected clinical parameters were investigated using multivariate logistic regression. RESULTS: Analyses were focused on the four questions showing a median ΔIBDQ-B>0. No dose volume/surface parameters were predictive, other than ΔIBDQ5≥3 (loose stools): when grouping patients according to bowel DVHs (high risk: V20>470cc, V30>245cc, V42>110cc; low risk: all the remaining patients), a two-variable model including high-risk DVH-shape (OR: 9.3) and age (protective, OR: 0.94) was assessed. The model showed good calibration (slope: 1.003, R2=0.92) and was found to be robust after bootstrap-based internal validation. CONCLUSIONS: Constraining the bowel loops may reduce the risk of loose stools. The risk is higher for younger patients.

Physicists' views on hadrontherapy: a survey of members of the Italian Association of Medical Physics (AIFM).

BACKGROUND: This study was based on a survey to investigate perceptions of hadrontherapy of the members of the Italian Association of Medical Physics (AIFM). The survey was digitally submitted to the 991 members between the end of January and the beginning of April 2016. METHODS: A 19-item questionnaire was designed focusing on advantages and disadvantages of hadrontherapy, current status and possible future improvements, and need and opportunities for future investments in Italy and abroad. Information about professional qualifications, main fields of clinical involvement and specific competencies of the respondents was also collected. RESULTS: The survey was completed by 121 AIFM members (response rate 12.2%). In the answers collected, it was shown that medical physicists expressed interest in hadrontherapy mainly for reasons of personal interest rather than for professional needs (90% ± 2.5% vs. 52% ± 4.3% of the respondents, respectively), with a good knowledge of the related basic aspects as well as of the pros and cons of its application. However, poor knowledge of the current status of hadrontherapy was observed among the medical physicists not directly involved at a professional level, who were less than 3% of the physicists working in radiotherapy. CONCLUSIONS: In light of these results, the implementation of new training and education initiatives should be devised to promote a deeper and global knowledge of hadrontherapy-related issues, not only from a theoretical point of view but also in practical terms. Moreover, a close collaboration between highly specialized medical physicists employed in hadrontherapy centers and others in oncology hospitals should be -encouraged.

Eleven-year management of prostate cancer patients on active surveillance: what have we learned?

PURPOSE: To evaluate the outcomes of active surveillance (AS) on patients with low-risk prostate cancer (PCa) and to identify predictors of disease reclassification. METHODS: In 2005, we defined an institutional AS protocol (Sorveglianza Attiva Istituto Nazionale Tumori [SAINT]), and we joined the Prostate Cancer Research International: Active Surveillance (PRIAS) study in 2007. Eligibility criteria included clinical stage ≤T2a, initial prostate-specific antigen (PSA) <10 ng/mL, and Gleason Pattern Score (GPS) ≤3 + 3 (both protocols); ≤25% positive cores with a maximum core length containing cancer ≤50% (SAINT); and ≤2 positive cores and PSA density <0.2 ng/mL/cm3 (PRIAS). Switching to active treatment was advised for a worsening of GPS, increased positive cores, or PSA doubling time <3 years. Active treatment-free survival (ATFS) was assessed using the Kaplan-Meier method. Factors associated with ATFS were evaluated with a multivariate Cox proportional hazards model. RESULTS: A total of 818 patients were included: 200 in SAINT, 530 in PRIAS, and 88 in personalized AS monitoring. Active treatment-free survival was 50% after a median follow-up of 60 months. A total of 404/818 patients (49.4%) discontinued AS: 274 for biopsy-related reclassification, 121/404 (30%) for off-protocol reasons, 9/404 (2.2%) because of anxiety. Biopsy reclassification was associated with PSA density (hazard ratio [HR] 1.8), maximum percentage of core involvement (HR 1.5), positive cores at diagnostic biopsy (HR 1.6), older age (HR 1.5), and prostate volume (HR 0.6) (all p<0.01). Patients from SAINT were significantly more likely to discontinue AS than were the patients from PRIAS (HR 1.65, p<0.0001). CONCLUSIONS: Five years after diagnosis, 50% of patients with early PCa were spared from active treatment. Wide inclusion criteria are associated with lower ATFS. However, at preliminary analysis, this does not seem to affect the probability of unfavorable pathology.

Follow-up of elderly patients with urogenital cancers: Evaluation of geriatric care needs and related actions.

OBJECTIVES: To investigate a comprehensive geriatric assessment (CGA) with subsequent investigation of healthcare patterns in older patients with urological cancers undergoing initial surgery or radiotherapy, to verify the usefulness of the incorporation of geriatric principles in future care plans. MATERIAL AND METHODS: This is a prospective cohort study. From November 2011 to March 2015, CGA was offered to all patients aged 70+ years treated with radiotherapy or surgery at seven tertiary centers. Patients were classified as fit, vulnerable, or frail according to Balducci's definition. CGA and follow-up data were collected by two trained evaluators at 6 and 12months. The information collected was not available to the caring physicians during follow-up. RESULTS: CGA was performed in 453 patients with prostate cancer (295), bladder cancer (126), or kidney cancer (32). 40% of patients with prostate cancer were fit, 47% vulnerable, and 13% frail. The corresponding values for renal cancer were 25%, 40%, and 34%, and for bladder cancer, 21%, 42%, and 37%. During follow-up, 60% of patients with cardiac diseases, 42% of those with diabetes/other metabolic disorders, 35% of those with hypertension, and 35% of those with respiratory diseases were followed by a specialist (for these severe/extremely severe comorbidities). Of 16 patients with ADL impairment and 63 with IADL impairment, only 4 (25%) and 6 (10%), respectively, were referred to a rehabilitation service. Only one case was referred to a geriatrician. CONCLUSIONS: Appropriate clinical care patterns are advisable to improve quality of survivorship in older patients with urological cancers.

An accurate method to quantify breathing-induced prostate motion for patients implanted with electromagnetic transponders.

PURPOSE: To validate and apply a method for the quantification of breathing-induced prostate motion (BIPM) for patients treated with radiotherapy and implanted with electromagnetic transponders for prostate localization and tracking. METHODS: For the analysis of electromagnetic transponder signal, dedicated software was developed and validated with a programmable breathing simulator phantom. The software was then applied to 1,132 radiotherapy fractions of 30 patients treated in supine position, and to a further 61 fractions of 2 patients treated in prone position. RESULTS: Application of the software in phantom demonstrated reliability of the developed method in determining simulated breathing frequencies and amplitudes. For supine patients, the in vivo analysis of BIPM resulted in median (maximum) amplitudes of 0.10 mm (0.35 mm), 0.24 mm (0.66 mm), and 0.17 mm (0.61 mm) in the left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions, respectively. Breathing frequency ranged between 7.73 and 29.43 breaths per minute. For prone patients, the ranges of the BIPM amplitudes were 0.1-0.5 mm, 0.5-1.3 mm, and 0.7-1.7 mm in the LR, CC, and AP directions, respectively. CONCLUSIONS: The developed method was able to detect the BIPM with sub-millimeter accuracy. While for patients treated in supine position the BIPM represents a reduced source of treatment uncertainty, for patients treated in prone position, it can be higher than 3 mm.

Phase II multi-institutional clinical trial on a new mixed beam RT scheme of IMRT on pelvis combined with a carbon ion boost for high-risk prostate cancer patients.

PURPOSE: Definition of the optimal treatment schedule for high-risk prostate cancer is under debate. A combination of photon intensity modulated radiotherapy (IMRT) on pelvis with a carbon ion boost might be the optimal treatment scheme to escalate the dose on prostate and deliver curative dose with respect to normal tissue and quality of dose distributions. In fact, carbon ion beams offer the advantage to deliver hypofractionated radiotherapy (RT) using a significantly smaller number of fractions compared to conventional RT without increasing risks of late effects. METHODS: This study is a prospective phase II clinical trial exploring safety and feasibility of a mixed beam scheme of carbon ion prostate boost followed by photon IMRT on pelvis. The study is designed to enroll 65 patients with localized high-risk prostate cancer at 3 different oncologic hospitals: Istituto Europeo di Oncologia, Fondazione IRCCS Istituto Nazionale dei Tumori, and Centro Nazionale di Adroterapia Oncologica. The primary endpoint is the evaluation of safety and feasibility with acute toxicity scored up to 1 month after the end of RT. Secondary endpoints are treatment early (3 months after the end of RT) and long-term tolerability, quality of life, and efficacy. RESULTS: The study is not yet recruiting; in silico studies are ongoing and we expect to start recruitment by 2017. CONCLUSIONS: The present clinical trial aims at improving the current treatment for high-risk prostate cancer, evaluating safety and feasibility of a new RT mixed-beam scheme including photons and carbon ions. Encouraging results are coming from carbon ion facilities worldwide on the treatment of different tumors including prostate cancers. Carbon ions combine physical properties allowing for high dose conformity and advantageous radiobiological characteristics. The proposed mixed beam treatment has the advantage to combine a photon high conformity standard of care IMRT phase with a hypofractionated carbon ion RT boost delivered in a short overall treatment time.

Hadrontherapy from the Italian Radiation Oncologist point of view: face the reality. The Italian Society of Oncological Radiotherapy (AIRO) survey.

Hadrontherapy has been in constant progress in the past decades. Due to the increasing interest in this field and the spreading of the technique in Italy and worldwide, the Italian Society of Radiation Oncology surveyed (by an online survey) its members regarding their perception of hadrontherapy. The survey outline addressed different items all related to hadrontherapy, such as: demographics (3 items), personal knowledge (5 items), actual use in clinical practice (5 items), and future perspectives and development (5 items). The survey was filled in by 224 radiation oncologists (RO). Among them, 74.6 % were RO with more than 5 years of clinical practice, and only 10.4 % RO in training. Median age was 46 years (range 27-77). 32.24 % admitted average knowledge about heavy particles radiobiology rationale and 32.42 % about the ongoing particle therapy clinical trials. Radioresistant tumors are perceived as-principal indications for carbon ions in 39.3 % of responders, and pediatric malignancies for protons in 37 %. Re-irradiation is highly recommended for 52.2 %. Strikingly, 38.8 % of participating ROs reported that, in the daily clinical practice, approximately less than 1 out of 10 patients asks to be referred for hadrontherapy. On the other side, 35.7 % claimed need for at least 3 up to 5 particle therapy centers in Italy. Overall, the results of the present survey highlight the interest of the Italian RO community for particle therapy among the other radiotherapy technique. Analysis of our results might picture the clinical attitude of the RO community towards hadrontherapy in Italy, and help in promoting targeted initiatives to spread clinical results and knowledge about technical innovations in this field.

Lifestyle interventions to improve the quality of life of men with prostate cancer: A systematic review of randomized controlled trials.

Improving quality of life is a key issue for patients with prostate cancer (PCa). Lifestyle interventions could positively impact the quality of life of patients. However, there is no clear-cut understanding of the role of diet, exercise and risky behaviour reduction in improving the quality of life of men with PCa. The aim of this review was to systematically summarize randomized controlled trials on lifestyle in PCa patients with quality of life as main outcome. 17 trials were included. Most of them referred to exercise interventions (71%) and involved men undergoing androgen deprivation therapy (47%). Exercise studies yielded the greater amount of positive results on quality of life outcomes (67%), followed by dietary interventions (50%) and combined lifestyle interventions (33%). In particular, supervised exercise programs with resistance training sessions were the ones producing greater convincing evidence for benefits on quality of life. Further studies with high methodological quality providing adequate information to develop evidence-based, personalized lifestyle interventions that can effectively ameliorate PCa-related quality of life are needed.

Effect of radiochemical modification on biodistribution of scFvD2B antibody fragment recognising prostate specific membrane antigen.

Antibody-based reagents represent a promising strategy as clinical diagnostic tools. Prostate cancer (PCa) is the second-leading cause of death in males in the Western population. There is a presently unmet need for accurate diagnostic tool to localize and define the extent of both primary PCa and occult recurrent disease. One of the most suitable targets for PCa is the prostate-specific membrane antigen (PSMA) recognised by the monoclonal antibody D2B that we re-shaped into the single chain Fv (scFv format). Aim of this study was to evaluate in preclinical in vivo models the target specificity of scFvD2B after labelling with different radionuclides. (111)In radiolabelling was performed via the chelator Bz-NOTA, and (131)I radioiodination was performed using iodogen. The potential for molecular imaging and the biological behaviour of the radiolabelled scFvD2B were evaluated in mice bearing two subcutaneous PCa isogenic cell lines that differed only in PSMA expression. Biodistribution studies were performed at 3, 9, 15 and 24h after injection to determine the optimal imaging time point. A significant kidney accumulation, as percentage of injected dose of tissue (%ID/g), was observed for (111)In-scFvD2B at 3h after injection (45%ID/g) and it was maintained up to 24h (26%ID/g). By contrast, kidney accumulation of (131)I-scFvD2B was only marginally (0.3%ID/g at 24h). At the optimal time point defined between 15h and 24h, regardless of the radionuclide used, the scFvD2B was able to localize significantly better in the PSMA expressing tumours compared to the negative control; with (131)I-scFvD2B yielding a significantly better target/background ratio compared to (111)In-scFvD2B. These data suggest that, besides antigen specificity, chemical modification may affect antibody fragment biodistribution.

Improving plan quality and consistency by standardization of dose constraints in prostate cancer patients treated with CyberKnife.

Treatment plans for prostate cancer patients undergoing stereotactic body radiation therapy (SBRT) are often challenging due to the proximity of organs at risk. Today, there are no objective criteria to determine whether an optimal treatment plan has been achieved, and physicians rely on their personal experience to evaluate the plan's quality. In this study, we propose a method for determining rectal and bladder dose constraints achievable for a given patient's anatomy. We expect that this method will improve the overall plan quality and consistency, and facilitate comparison of clinical outcomes across different institutions. The 3D proximity of the organs at risk to the target is quantified by means of the expansion-intersection volume (EIV), which is defined as the intersection volume between the target and the organ at risk expanded by 5 mm. We determine a relationship between EIV and relevant dosimetric parameters, such as the volume of bladder and rectum receiving 75% of the prescription dose (V75%). This relationship can be used to establish institution-specific criteria to guide the treatment planning and evaluation process. A database of 25 prostate patients treated with CyberKnife SBRT is used to validate this approach. There is a linear correlation between EIV and V75% of bladder and rectum, confirming that the dose delivered to rectum and bladder increases with increasing extension and proximity of these organs to the target. This information can be used during the planning stage to facilitate the plan optimization process, and to standardize plan quality and consistency. We have developed a method for determining customized dose constraints for prostate patients treated with robotic SBRT. Although the results are technology specific and based on the experience of a single institution, we expect that the application of this method by other institutions will result in improved standardization of clinical practice.