Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis.

PURPOSE: To compare volumetric modulated arc therapy with flattening filter free (FFF) and flattening filter (FF) beams in patients with hepatic metastases subject to hypofractionated radiotherapy (RT). METHODS: A planning study on 13 virtual lesions of increasing volume was performed. Two single arc plans were optimized with the RapidArc technique using either FFF or FF beams. A second planning study was performed on ten patients treated for liver metastases to validate conclusions. In all cases, a dose of 75 Gy in 3 fractions was prescribed to the planning target volume (PTV) and plans were evaluated in terms of coverage, homogeneity, conformity, mean dose to healthy liver and to healthy tissue. For each parameter, results were expressed in relative terms as the percentage ratio between FFF and FF data. RESULTS: In terms of PTV coverage, conformity index favored FFF for targets of intermediate size while FF resulted more suitable for small (<100 cm(3)) and large (>300 cm(3)) targets. Plans optimized with FFF beams resulted in increased sparing of healthy tissue in ≈85% of cases. Despite the qualitative results, no statistically significant differences were found between FFF and FF results. Plans optimized with un-flattened beams resulted in higher average MU∕Gy than plans with FF beams. A remarkable and significant difference was observed in the beam-on time (BOT) needed to deliver plans. The BOT for FF plans was 8.2 ± 1.0 min; for FFF plans BOT was 2.2 ± 0.2 min. CONCLUSIONS: RapidArc plans optimized using FFF were dosimetrically equivalent to those optimized using FF beams, showing the feasibility of SBRT treatments with FFF beams. Some improvement in healthy tissue sparing was observed when using the FFF modality due to the different beam's profile. The main advantage was a considerable reduction of beam-on time, relevant for SBRT techniques.

Long-term local control achieved after hypofractionated stereotactic body radiotherapy for adrenal gland metastases: a retrospective analysis of 34 patients.

AIMS AND BACKGROUND: To describe feasibility, tolerability and clinical outcomes of stereotactic body radiation therapy (SBRT) in the treatment of adrenal metastases in 34 consecutive cancer patients. MATERIAL AND METHODS: Between March 2004 and July 2010, a total of 34 consecutive patients, accounting for 36 adrenal metastatic lesions, were treated with SBRT. SBRT treatments were delivered by a Linac Varian 600 with microMLC (3DLine, Elekta, Stockholm, Sweden) and a Linac ELEKTA Precise (Elekta). All 34 patients were clinically and radiologically evaluated during and after completion of SBRT. Following outcomes were taken into account: best clinical response at any time, local control, time to systemic progression, time to local progression, overall survival and toxicity. Survival was estimated by the Kaplan-Meier method and factor potentially affecting outcomes were analyzed with Cox regression analysis. RESULTS: Total RT doses ranged from 20 Gy in 4 fractions to 45 Gy in 18 fractions (median dose: 32 Gy; median number of fractions: 4). All doses were prescribed to the 95% isodose line. No cases of Grade ≥ 3 toxicity were recorded. At a median follow-up time of 41 months (range, 12-75) 22 patients were alive. Three of 28 lesions (11%) showed complete response, 13/28 (46%) partial response, 10/28 (36%) stable disease and 2/28 (7%) progressed in the treated area. Local failure was observed in 13 cases. Actuarial local control rates at one and two years were 66% and 32%, respectively. Median time to local progression was 19 months. Median survival was 22 months. CONCLUSION: SBRT in adrenal gland metastasis is feasible without significant acute and late toxicities, with a good rate of local control. New SBRT fractionation schemes and the possibility to combine new systemic approaches should be investigated in order to further increase local control and reduce systemic disease progression.

Anatomy driven optimization strategy for total marrow irradiation with a volumetric modulated arc therapy technique.

The purpose of this study was to evaluate the possibility of dose distribution optimization for total marrow irradiation (TMI) employing volumetric-modulated arc therapy (VMAT) with RapidArc (RA) technology setting isocenter's positions and jaw's apertures according to patient's anatomical features. Plans for five patients were generated with the RA engine (PROIII): eight arcs were distributed along four isocenters and simultaneously optimized with collimator set to 90°. Two models were investigated for geometrical settings of arcs: (1) in the "symmetric" model, isocenters were equispaced and field apertures were set the same for all arcs to uniformly cover the entire target length; (2) in the "anatomy driven" model, both field sizes and isocenter positions were optimized in order to minimize the target volume near the field edges (i.e., to maximize the freedom of motion of MLC leaves inside the field aperture (for example, avoiding arcs with ribs and iliac wings in the same BEV)). All body bones from the cranium to mid of the femurs were defined as PTV; the maximum length achieved in this study was 130 cm. Twelve (12) Gy in 2 Gy/fractions were prescribed in order to obtain the covering of 85% of the PTV by 100% of the prescribed dose. For all organs at risk (including brain, optical structures, oral and neck structures, lungs, heart, liver, kidneys, spleen, bowels, bladder, rectum, genitals), planning strategy aimed to maximize sparing according to ALARA principles, looking to reach a mean dose lower than 6 Gy (i.e., 50% of the prescribed dose). Mean MU/fraction resulted 3184 ± 354 and 2939 ± 264 for the two strategies, corresponding to a reduction of 7% (range -2% to 13%) for (1) and (2). Target homogeneity, defined as D(2%)-D(98%) was 18% better for (2). Mean dose to the healthy tissue, defined as body minus PTV, had 10% better reduction with (2). The isocenter's position and the jaw's apertures are significant parameters in the optimization of the TMI with RA technique, giving the medical physicist a crucial role in driving the optimization and thus obtaining the best plan. A clinical protocol started in our department in October 2010.

Immunotherapy with radiotherapy fails to improve prognosis of patients with stage IV non-small cell lung cancer: a retrospective cohort analysis of the THUNDER-2 study.

Background: Radiotherapy (RT) may enhance the systemic antitumor reaction to immunotherapy (IT). Currently, the effect of RT in stage IV non-small cell lung cancer (NSCLC) patients treated with IT is uncertain. This study aimed to confirm the role of RT in these patients. Methods: We enrolled 120 stage IV NSCLC patients who had been treated with IT and had received external beam radiation therapy (EBRT) or radioactive particle implantation (RPI) at 3 oncology centers in Shandong province between 2019 and 2021. We assessed relevant clinical factors and regular follow-up was conducted via electronic medical records and telephone. The primary endpoint was overall survival (OS). Different combination models in various populations were compared by generating Kaplan-Meier curves and Cox regression analysis. Results: The OS for the overall population was 5 months (range, 0-31 months) and the overall survival rate was 47.5%. Patients receiving IT with RPI had the least favorable prognostic trend (median survival: 2 months) compared to those receiving IT without RT (median survival: 9 months) and IT with EBRT (median survival: 10 months), but this difference was not significant (P=0.148). In subgroup analysis, patients treated with IT with RPI appeared to have a worse prognosis in some specific cohorts, such as males [hazard ratio (HR) =2.433, P=0.031], non-squamous carcinoma histologies (HR =2.680, P=0.034), patients with oligometastases (HR =7.967, P=0.024), patients with liver metastases (HR =10.808, P=0.011) or brain metastases (HR =20.087, P=0.005), and those with Eastern Cooperative Oncology Group (ECOG) performance score ≥2 (HR =2.769, P=0.043). Multivariate Cox analysis of total population revealed that ECOG score and IT stage were the independent prognostic factors. IT combined with EBRT did not have a significant survival benefit in all subgroups. Concurrent IT with RT and first-line and second-line IT combined with RT trended toward improved long-term prognosis. Conclusions: While the robustness of the present conclusions is limited by relatively small sample size and retrospective nature of this research, the addition of EBRT or RPI to IT did not significantly improve patients' OS in stage IV NSCLC. Early combination IT after RT may benefit patients with long-term survival.

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.

Stereotactic body radiation therapy (SBRT) for adrenal metastases : a feasibility study of advanced techniques with modulated photons and protons.

PURPOSE: To compare advanced treatment techniques with photons and protons as a stereotactic body radiation therapy (SBRT) for adrenal glands metastases. MATERIALS AND METHODS: Planning computer tomographic (CT) scans of 10 patients were selected. A total dose of 45 Gy in 7.5 Gy fractions was prescribed. Organs at risk (OAR) were liver and kidneys. Dose-volume metrics were defined to quantify quality of plans assessing target coverage and sparing of organs at risk. Plans for RapidArc, intensity-modulated radiotherapy (IMRT), dynamic conformal arcs, 3D conformal static fields, and intensity modulated protons were compared. The main planning objective for the clinical target volume (CTV) was to cover 100% of the volume with 95% (V(95%) = 100%) and to keep the maximum dose below 107% of the prescribed dose (V(107%) = 0%). Planning objective for planning target volume (PTV) was V(95%) > 80%. For kidneys, the general planning objective was V(15Gy) < 35% and for liver V(15Gy) < (liver volume-700 cm(3)). RESULTS: All techniques achieved the minimum and maximum dose objective for CTV and PTV, D(5-95%) ranged from 1 Gy (protons) to 1.6 Gy (conformal static fields) on CTV. Maximal organ at risk sparing was achieved by protons. RapidArc presented the second lowest dose bath (V(10Gy) and integral dose) after protons and the best conformality together with IMRT. CONCLUSIONS: Stereotactic body radiation therapy (SBRT) to adrenal glands metastases is achievable with several advanced techniques with either photons or protons. The intensity modulated approaches using either static fields, dynamic arcs or protons are superior to the other conformal solutions. For their simplicity, IMRT or RapidArc should be considered as the first option radiation treatment for those patients not eligible for proton treatment.

Stereotactic body radiation therapy for abdominal targets using volumetric intensity modulated arc therapy with RapidArc: feasibility and clinical preliminary results.

PURPOSE: To report early clinical experience in stereotactic body radiation therapy (SBRT) delivered using volumetric intensity modulated arc therapy with RapidArc (RA) in patients with primary or metastatic tumours at abdominal sites. MATERIAL AND METHODS: Thirty-seven consecutive patients were treated using RA. Of these, 16 had primary or metastatic liver tumours, nine had pancreatic cancer and 12 a nodal metastasis in the retro-peritoneum. Dose prescription varied from 45 to 75 Gy to the Clinical Target Volume in 3 to 6 fractions. The median follow-up was 12 months (6-22). Early local control and toxicity were investigated and reported. RESULTS: Planning objectives on target volumes and organs at risk were met in most cases. Delivery time ranged from 2.8 ± 0.3 to 9.2 ± 2.4 minutes and pre-treatment plan verification resulted in a Gamma Agreement Index from 95.3 ± 3.8 to 98.3 ± 1.7%. At the time of analysis, local control (freedom from progression) at six months, was assessable in 24 of 37 patients and was achieved in 19 patients with a crude rate of 79.2%. Seven patients experienced treatment-related toxicity. Three patients experienced a mild and transient G1 enteritis and two showed a transient G1 liver damage. Two had late toxicity: one developed chronic enteritis causing G1 diarrhoea and G1 abdominal pain and one suffered at three months a G3 gastric bleeding. No patients experienced G4 acute toxicity. CONCLUSIONS: SBRT for abdominal targets delivered by means of RA resulted to be feasible with good early clinical results in terms of local control rate and acute toxicity profile. RA allowed to achieve required target coverage as well as to keep within normal tissue dose/volume constraints.

A case of sudden brain metastases progression after temporary targeted therapy discontinuation: when to regret a drug holiday.

Targeted therapy improves outcomes in BRAF V600-mutant metastatic melanoma with active brain metastases. We present the case of a patient with rapid brain disease progression upon temporary targeted therapy discontinuation and unusual rapid disease response upon treatment resumption. This report presents a 78-year-old woman with metastatic BRAF V600E positive melanoma (bladder and brain localizations). The patient started first-line dabrafenib and trametinib with good tolerability and evidence of complete response (CR). After 8 months of maintained CR, the patient took a drug holiday for 14 days. Brain MRI performed after treatment pause showed extensive disease progression, whereas extracranial staging was negative. The patient was asymptomatic: she restarted targeted therapy and underwent evaluation for whole-brain radiotherapy. Brain computed tomography scan and subsequent MRI performed to plan radiotherapy showed brain CR after only 10 days of targeted therapy resumption. The patient continued treatment, and radiotherapy indication was withheld. Repeated brain MRI confirmed maintained CR. Treatment with dabrafenib and trametinib is ongoing with excellent tolerability. Rapid intracranial progression is a well-known finding after discontinuation of combined targeted therapy in the case of extracranial progressive disease. This is the first report of documented disease progression upon temporary treatment discontinuation for reasons other than toxicity, with an unusual response after retreatment. Caution should be used in tailoring treatment during targeted therapy, allowing pauses for reasons other than toxicity. Strict adherence to treatment is paramount to guarantee disease control.

Cone beam CT pre- and post-daily treatment for assessing geometrical and dosimetric intrafraction variability during radiotherapy of prostate cancer.

The purpose of this study was to quantify the relationship between treatment time and dose uncertainty due to intrafraction organ motion in prostate cancer radiotherapy (RT). Ten consecutive patients with prostate cancer treated by radical RT by volumetric modulated arc therapy (RapidArc) were considered. For each patient, pre- and post-treatment cone beam computed tomography (CBCT) was performed in 10 fractions. The prostate, rectum and bladder were contoured on each CBCT. The change in organ position, volume and dosimetric uncertainty induced by organ motion were evaluated. Interval time between the two CBCTs ranged between 4 and 16 min (mean 7.3 ± 0.7 min). Treatment with intrafraction prostate motion >3mm and > 5 mm were 24% and 5%, respectively. Regarding change in centroid position and volume, a poor time correlation was found for target and rectum, while a constant increase was obtained for bladder. The agreement index was highly correlated to time (r = -0.89 for bladder, r = -0.95 for rectum, and r= -0.84 for prostate). In terms of difference in dose volume histogram between pre- and post-CBCT, the dose uncertainties for the targets and rectum amplified with the increasing time. The increasing intrafraction dose uncertainty with time requires the use of an RT technique with minimization of treatment time to improve confidence in planning dose distribution.

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.

A double-blind, randomised, vehicle-controlled clinical study to evaluate the efficacy of MAS065D in limiting the effects of radiation on the skin: interim analysis.

Our aim was to assess the efficacy of MAS065D, a non-steroidal water-in-oil cream, in preventing and limiting skin reactions caused by radiation therapy (RT). 40 women treated with conservative breast cancer surgery followed by radiotherapy, were randomised to receive MAS065D (22 pts) or vehicle (18 pts). Radiotherapy was delivered in 20 fractions: 2.25 Gy to the whole breast plus a concomitant boost of 0.25 Gy to the tumour bed up to a total dose of 50 Gy. Evaluations of skin toxicity, erythema, and subjective symptoms were carried out weekly and 3 weeks after treatment completion. A statistically significant difference between vehicle and MAS065D groups was recorded regarding the maximum severity of skin toxicity (p < 0.0001), burning within the radiation field (p = 0.039) and desquamation (p = 0.02), in favour of the latter. We conclude that MAS065D may be considered a safe and effective treatment in the prevention and minimization of skin reactions and associated symptoms.

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.

Benefit on biochemical control of adjuvant radiation therapy in patients with pathologically involved seminal vesicles after radical prostatectomy.

AIMS AND BACKGROUND: To determine whether there is a benefit for biochemical control with adjuvant radiation therapy to the surgical bed following radical prostatectomy in patients with seminal vesicle invasion and pathologically negative pelvic lymph nodes (pT3b-pT4 pN0). METHODS: We retrospectively reviewed the clinical records of radical prostatectomy patients treated between 1995 and 2002. A total of 66 patients with seminal vesicle invasion were identified: 45 of these patients received adjuvant radiation therapy and 21 were observed. Radiation therapy was initiated within 4 months of prostatectomy. Median dose was 66 Gy (range, 60-70 Gy). Median follow-up from the day of surgery was 40.6 months (mean, 41.5; range, 12-99). Biochemical recurrence was defined as the first value > or = 0.2 ng/ml. RESULTS: At two years, the proportion of patients free from biochemical recurrence was 80% in patients who received adjuvant radiation therapy versus 54% for those not given radiation therapy (P = 0.036). Actuarial biochemical recurrence at 5 years was 59% vs 41% for the radiation therapy and no radiation therapy groups, respectively. On univariate Cox regression model, the hazard of biochemical failure was also associated with a detectable (> or = 0.2 ng/ml) postsurgical prostate-specific antigen (P = 0.02) prior to radiation therapy. Pathological T stage (pT3b vs pT4), Gleason score, primary Gleason pattern and positive surgical margins were not significantly associated with biochemical recurrence. The hazard of biochemical failure was around 85% lower in the radiation therapy group than in the observation group (P = 0.002). CONCLUSIONS: Data from the present series suggest that adjuvant radiation therapy for patients with seminal vesicle invasion and undetectable (< or = 0.2 ng/ml) postoperative prostate-specific antigen significantly reduces the likelihood of biochemical failure.

Radiotherapy for head and neck cancer in Lombardy: a survey by the Lombardy Group of the Italian Association for Radiation Oncology.

AIMS: In 2013, a survey was conducted to analyze the available resources and their use in the radiation treatment of patients with malignancies of the head and neck region in Lombardy, on behalf of the Lombardy group of the Italian Association of Radiation Oncology. METHODS: A questionnaire was sent to 26 of 34 radiotherapy centers active in the region. Two centers were excluded because they did not treat head and neck cancers (Besta Neurological Institute and Cyberknife center), 4 had started their activity in 2013 or late 2012, and 2 satellite centers had their results included in the main center's response. Items investigated included number of patients with head and neck cancer treated in 2012, general technical issues, and integration with surgery and chemotherapy. RESULTS: Twenty-four questionnaires were returned (92% response rate). There was a good consistency on the use of radiotherapy in different settings, whereas integration with chemotherapy showed more heterogeneous data. Treatment techniques were 3D conformal radiotherapy or intensity-modulated radiotherapy with image-guided radiotherapy in most cases and a low rate of treatment-related death was observed. CONCLUSIONS: This survey provides important data on the use of radiotherapy resources for patients with head and neck cancer in Lombardy. The data offer the opportunity to further investigate issues that could better standardize head and neck cancer treatment and allocate resources across the region.

Finding dose-volume constraints to reduce late rectal toxicity following 3D-conformal radiotherapy (3D-CRT) of prostate cancer.

BACKGROUND AND PURPOSE: The rectum is known to display a dose-volume effect following high-dose 3D-conformal radiotherapy (3D-CRT). The aim of the study is to search for significant dose-volume combinations with the specific treatment technique and patient set-up currently used in our institution. PATIENTS AND METHODS: We retrospectively analyzed the dose-volume histograms (DVH) of 135 patients with stage T1b-T3b prostate cancer treated consecutively with 3D-CRT between 1996 and 2000 to a total dose of 76 Gy. The median follow-up was 28 months (range 12-62). All late rectal complications were scored using RTOG criteria. Time to late toxicity was assessed using the Kaplan-Meyer method. The association between variables at baseline and > or=2 rectal toxicity was tested using chi(2) test or Fisher's exact test. A multivariate analysis using logistic regression was performed. RESULTS: Late rectal toxicity grade > or=2 was observed in 24 of the 135 patients (17.8%). A 'grey area' of increased risk has been identified. Average DVHs of the bleeding and non-bleeding patients were generated. The area under the percent volume DVH for the rectum of the bleeding patients was significantly higher than that of patients without late rectal toxicity. On multivariate analysis the correlation between the high risk DVHs and late rectal bleeding was confirmed. CONCLUSIONS: The present analysis confirms the role of the rectal DVH as a tool to discriminate patients undergoing high-dose 3D-CRT into a low and a high risk of developing late rectal bleeding. Based on our own results and taking into account the data published in the literature, we have been able to establish new dose-volume constraints for treatment planning: if possible, the percentage of rectal volume exposed to 40, 50, 60, 72 and 76 Gy should be limited to 60, 50, 25, 15 and 5%, respectively.

Androgen ablation therapy does not increase the risk of late morbidity following 3D-conformal radiotherapy of organ-confined prostate cancer: the experience of the European Institute of Oncology.

AIMS AND BACKGROUND: Androgen ablation therapy in conjunction with radiotherapy--neoadjuvant and adjuvant--has consistently been shown to be associated with improved biochemical and local control, whereas controversy still remains as regards its benefit in terms of overall survival. The objective of this study is to determine the impact of androgen ablation in combination to 3D-conformal radiotherapy on late treatment-related toxicity. METHODS: 236 patients were treated with 3D-conformal radiotherapy to a total dose ranging from 70 and 78.6 Gy. Fifty-six patients did not receive any form of androgen ablation whereas 176 were given at least 3 months of neoadjuvant androgen ablation. Of these, 64 stayed on androgen ablation for a median time of 6 months post-radiotherapy. Acute toxicity was evaluated weekly during the course of treatment. Late toxicity was assessed at 3-months intervals during the follow-up. Toxicity was scored according to the RTOG criteria. RESULTS: The median follow-up was 24.6 months (range, 12-62). The incidence of late genitourinary toxicity was: 3% G2, 3.5% G3, 0.5% G4. The incidence of late gastrointestinal toxicity was: 12% G2, 2% G3, 1% G4. No association was observed between the use of androgen ablation and late treatment-related toxicity. High-risk patients who continued on androgen ablation long-term were not found to have an increased risk of developing late toxicity with respect to those who never had any form of androgen ablation or those only treated neoadjuvantly. CONCLUSIONS: In our experience, the use of androgen ablation does not impact on late toxicity following high dose 3D-conformal radiotherapy for prostate cancer.

Stereotactic body radiation therapy for liver tumours using flattening filter free beam: dosimetric and technical considerations.

PURPOSE: To report the initial institute experience in terms of dosimetric and technical aspects in stereotactic body radiation therapy (SBRT) delivered using flattening filter free (FFF) beam in patients with liver lesions. METHODS AND MATERIALS: From October 2010 to September 2011, 55 consecutive patients with 73 primary or metastatic hepatic lesions were treated with SBRT on TrueBeam using FFF beam and RapidArc technique. Clinical target volume (CTV) was defined on multi-phase CT scans, PET/CT, MRI, and 4D-CT. Dose prescription was 75 Gy in 3 fractions to planning target volume (PTV). Constraints for organs at risk were: 700 cc of liver free from the 15 Gy isodose, Dmax < 21 Gy for stomach and duodenum, Dmax < 30 Gy for heart, D0.1 cc < 18 Gy for spinal cord, V15 Gy < 35% for kidneys. The dose was downscaled in cases of not full achievement of dose constraints. Daily cone beam CT (CBCT) was performed. RESULTS: Forty-three patients with a single lesion, nine with two lesions and three with three lesions were treated with this protocol. Target and organs at risk objectives were met for all patients. Mean delivery time was 2.8 ± 1.0 min. Pre-treatment plan verification resulted in a Gamma Agreement Index of 98.6 ± 0.8%. Mean on-line co-registration shift of the daily CBCT to the simulation CT were: -0.08, 0.05 and -0.02 cm with standard deviations of 0.33, 0.39 and 0.55 cm in, vertical, longitudinal and lateral directions respectively. CONCLUSIONS: SBRT for liver targets delivered by means of FFF resulted to be feasible with short beam on time.

Vertebral metastases reirradiation with volumetric-modulated arc radiotherapy.

PURPOSE: To assess the feasibility, acute toxicity, clinical improvement, local control and survival for spinal metastatic patients re-irradiated using volumetric-modulated-arc-radiotherapy (VMAT). METHODS AND MATERIALS: Between February 2009 and November 2010, 31 patients were treated. Surgery was performed in six before re-irradiation. The clinical target volume (CTV) was defined as the whole vertebrae with recurrence excluding the central section of spinal canal. Planning target volume was defined as CTV+0-5mm in the three directions. Dose was prescribed in order to have biological equivalent dose to the spinal cord from the two courses lower than 120 Gy(2) to 1 cc of the volume. Clinical improvement, toxicity and recurrence were evaluated. All patients had back pain before treatment and 15 (48%) neurological deficit. RESULTS: Clinical remission of pain was obtained in 29 patients (93%). Neurological improvement was observed in 73% of patients. No acute or late toxicities were recorded. No recurrence occurred. Median survival was 10 months (range 6-24). At the last follow-up 19 patients (61%) were alive and 12 (39%) dead from systemic disease progression. The 1 and 2 year survival were 55% and 35%, respectively. CONCLUSION: In patients with spinal metastases recurrence re-irradiation with VMAT is feasible and provides clinical benefit in most patients.

Clinical outcome of hypofractionated stereotactic radiotherapy for abdominal lymph node metastases.

PURPOSE: We report the medium-term clinical outcome of hypofractionated stereotactic body radiotherapy (SBRT) in a series of patients with either a solitary metastasis or oligometastases from different tumors to abdominal lymph nodes. METHODS AND MATERIALS: Between January 2006 and June 2009, 19 patients with unresectable nodal metastases in the abdominal retroperitoneal region were treated with SBRT. Of the patients, 11 had a solitary nodal metastasis and 8 had a dominant nodal lesion as part of oligometastatic disease, defined as up to five metastases. The dose prescription was 45 Gy to the clinical target volume in six fractions. The prescription had to be downscaled by 10% to 20% in 6 of 19 cases to keep within dose/volume constraints. The first 11 patients were treated with three-dimensional conformal techniques and the last 8 by volumetric intensity-modulated arc therapy. Median follow-up was 1 year. RESULTS: Of 19 patients, 2 had a local progression at the site of SBRT; both also showed concomitant tumor growth at distant sites. The actuarial rate of freedom from local progression was 77.8% ± 13.9% at both 12 and 24 months. Eleven patients showed progressive local and/or distant disease at follow-up. The 12- and 24-month progression-free survival rates were 29.5% ± 13.4% and 19.7% ± 12.0%, respectively. The number of metastases (solitary vs. nonsolitary oligometastases) emerged as the only significant variable affecting progression-free survival (p < 0.0004). Both acute and chronic toxicities were minimal. CONCLUSIONS: Stereotactic body radiotherapy for metastases to abdominal lymph nodes was shown to be feasible with good clinical results in terms of medium-term local control and toxicity rates. Even if most patients eventually show progressive disease at other sites, local control achieved by SBRT may be potentially significant for preserving quality of life and delaying further chemotherapy.

Feasibility and early clinical assessment of flattening filter free (FFF) based stereotactic body radiotherapy (SBRT) treatments.

PURPOSE: To test feasibility and safety of clinical usage of Flattening Filter Free (FFF) beams for delivering ablative stereotactic body radiation therapy (SBRT) doses to various tumor sites, by means of Varian TrueBeam™ (Varian Medical Systems). METHODS AND MATERIALS: Seventy patients were treated with SBRT and FFF: 51 lesions were in the thorax (48 patients),10 in the liver, 9 in isolated abdominal lymph node, adrenal gland or pancreas. Doses ranged from 32 to 75 Gy, depending on the anatomical site and the volume of the lesion to irradiate. Lung lesions were treated with cumulative doses of 32 or 48 Gy, delivered in 4 consecutive fractions. The liver patients were treated in 3 fractions with total dose of 75 Gy. The isolated lymph nodes were irradiated in 6 fractions with doses of 45 Gy. The inclusion criteria were the presence of isolated node, or few lymph nodes in the same lymph node region, in absence of other active sites of cancer disease before the SBRT treatment. RESULTS: All 70 patients completed the treatment. The minimum follow-up was 3 months. Six cases of acute toxicities were recorded (2 Grade2 and 2 Grade3 in lung and 2 Grade2 in abdomen). No patient experienced acute toxicity greater than Grade3. No other types or grades of toxicities were observed at clinical evaluation visits. CONCLUSIONS: This study showed that, with respect to acute toxicity, SBRT with FFF beams showed to be a feasible technique in 70 consecutive patients with various primary and metastatic lesions in the body.