Feasibility and safety of 1.5 T MR-guided and daily adapted abdominal-pelvic SBRT for elderly cancer patients: geriatric assessment tools and preliminary patient-reported outcomes.

BACKGROUND: We present preliminary data of the first older cancer patients treated with Hybrid Linac for stereotactic body radiotherapy (SBRT) consisting of 1.5 T MRI-guided and daily-adapted treatment. The aim was to assess feasibility, safety and the role of G8 and Charlson Comorbidity Index (CCI) questionnaires in predicting patients' QoL, evaluated by patient-reported outcome measures (PROMs). METHODS: Two groups of patients with localized prostate cancer or abdominal-pelvic oligometastases were analyzed. SBRT schedule consisted of 35 Gy delivered in 5 fractions. The primary endpoint was to measure the impact of G8 and CCI on PROMs. Both G8 and the CCI were performed at baseline, while the EORTC Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) for PROMs assessment was prospectively performed at baseline and after SBRT. RESULTS: Forty older patients were analyzed. The median age was 73 years (range 65-85). For the entire population, the median G8 score was 15 (10-17) and the median CCI score was 6 (4-11). Concerning the PROMS, the EORTC-QLQ C30 questionnaire reported no difference between the pre- and post-SBRT evaluation in all patients, except for the fatigue item that declined after SBRT, especially in the group of patients with a G8 score < 15 and with age < 75 years (p = 0.049). No grade 3 or higher acute toxicity occurred. CONCLUSION: This is the first report documenting for older cancer patients that 1.5 T MRI-guided daily-adapted SBRT is feasible, safe and does not impact on the QoL at the end of treatment. Longer follow-up is advocated to report long-term outcomes. TRIAL REGISTRATION: Date of approval April 2019 and numbered MRI/LINAC no. 23748.

Re-irradiation for recurrent glioma: outcome evaluation, toxicity and prognostic factors assessment. A multicenter study of the Radiation Oncology Italian Association (AIRO).

INTRODUCTION: The prognosis of glioma is dismal, and almost all patients relapsed. At recurrence time, several treatment options are considered, but to date there is no a standard of care. The Neurooncology Study Group of the Italian Association of Radiation Oncology (AIRO) collected clinical data regarding a large series of recurrent glioma patients who underwent re-irradiation (re-RT) in Italy. METHODS: Data regarding 300 recurrent glioma patients treated from May 2002 to November 2017, were analyzed. All patients underwent re-RT. Surgical resection, followed by re-RT with concomitant and adjuvant chemotherapy was performed. Clinical outcome was evaluated by neurological examination and brain MRI performed, 1 month after radiation therapy and then every 3 months. RESULTS: Re-irradiation was performed at a median interval time (IT) of 16 months from the first RT. Surgical resection before re-RT was performed in 19% of patients, concomitant temozolomide (TMZ) in 16.3%, and maintenance chemotherapy in 29%. Total doses ranged from 9 Gy to 52.5 Gy, with a median biological effective dose of 43 Gy. The median, 1, 2 year OS were 9.7 months, 41% and 17.7%. Low grade glioma histology (p  ≪ 0.01), IT > 12 months (p = 0.001), KPS > 70 (p = 0.004), younger age (p = 0.001), high total doses delivered (p = 0.04), and combined treatment performed (p = 0.0008) were recorded as conditioning survival. CONCLUSION: our data underline re-RT as a safe and feasible treatment with limited rate of toxicity, and a combined ones as a better option for selected patients. The identification of a BED threshold able to obtain a greater benefit on OS, can help in designing future prospective studies.

Cost-effectiveness of Linac-based single-isocenter non-coplanar technique (HyperArcTM) for brain metastases radiosurgery.

In the last few years, the major change has occurred in the expansion of indications for radiosurgery (SRS) to include patients with more than four brain metastases (BM). To address the expanding indications for SRS in the treatment of multiple BMs, HyperArcTM (Varian Medical System, Palo Alto, CA, U.S.) was recently introduced in order to automate and simplify sophisticated treatments such as SRS/FSRT for multiple lesions (up to 20 BM). In this editorial some consideration about HyperArc cost-effectiveness were discussed in terms of reduction of treatment delivery time (multiple intracranial targets can be treated in a few minutes), the reduction of overall treatment time (treatment course of SRS of multiple BMs in a single session, rather than having to irradiate lesion per lesion during separate sessions on different days); reduction of costs for health systems. In summary HyperArc™ system is a promising, safe and accurate solution for SRS/SFRT to treat multiple BMs in a single or few sessions. This has the potential to impact direct and indirect costs of SRS/SFRT delivery.

Moderate hypofractionation and simultaneous integrated boost by helical tomotherapy in prostate cancer: monoinstitutional report of acute tolerability assessment with different toxicity scales.

INTRODUCTION: Based on radiobiology evidence, hypofractionated radiotherapy has the potential of improving treatment outcome in prostate cancer patients. In this study, we evaluated the safety, in terms of acutetoxicity, of using moderate hypofractionated radiotherapy delivered with Helical Tomotherapy (HT) to treat prostate cancer patients. MATERIALS AND METHODS: Between December 2012 and April 2014, 42 consecutive patients were treated with hypofractionated radiotherapy using HT. All patients received 70 Gy in 28 fractions to PTV1, which included the prostate. In the intermediate risk group, 61.6 Gy were delivered to PTV2, which included the seminal vesicles. In high risk patients, the pelvic nodes were added (PTV3) and received 50.4 Gy. Acute toxicity was recorded prospectively with RTOG and Common Terminology Criteria for Adverse Events 3.0, retrospectively with CTCAE 4.0. Expanded Prostate Cancer Index Composite (EPIC) was measured at baseline and 3 months after end of treatment, to investigate health related quality of life with regards to bladder and gastrointestinal function. RESULTS: Acute toxicity was acceptable, independently from the system used to score side effects. Moderate genitourinary toxicity was more frequent than gastrointestinal toxicity. No correlation between acute side effects and patients' characteristics or physical dose parameters was registered. EPIC evaluation showed a negligible difference in urinary and bowel function post-treatment, that did not reach statistical significance. CONCLUSIONS: Our experience confirms the safety of moderate hypofractionation delivered with HT in prostate cancer patients with low, intermediate and high risk.

Stereotactic body radiotherapy with flattening filter-free beams for prostate cancer: assessment of patient-reported quality of life.

PURPOSE: Stereotactic body radiotherapy (SBRT) is an emerging treatment approach reported as safe and effective strategy for low- and intermediate-risk prostate cancer patients. End point of the current study is to appraise the patient-reported quality of life according to the expanded prostate cancer index composite (EPIC) questionnaire. METHODS: In the framework of a prospective mono-institutional phase II trial, EPIC questionnaire was dispensed (up to 1 year after treatment) to a cohort of 46 patients of 72 treated with 5 fractions of 7 Gy each to the prostate. SBRT was delivered with RapidArc VMAT with 10 MV flattening filter-free photon beams. RESULTS: Median follow-up of patients was 14.5 months (range: 6-23). Acute rectal toxicity was mild (only 23/72 cases with G1-2 and no G3-4) as well as urinary (50/72 G1-2 and no G3-4). At the moment, four cases of G1 late rectal toxicity and 22 cases of G1 urinary (1 of G2) were reported. Urinary, rectal, sexual, and hormonal scores resulted stable over time: 1 year scores resulted, respectively, in -0.3, +2.8, -1.7, and -2.8 % variations with respect to baseline. No significant differences were observed also when data were stratified according to functional and bother sub-scales. CONCLUSIONS: Stereotactic body radiotherapy (SBRT) treatment of prostate with RapidArc and high-intensity photon beams resulted to be well tolerated by patients with mild toxicity profiles and good patient-reported quality of life perception for the first year after treatment. Longer follow-up in the trial cohort is in progress.

Dose distribution changes with shielding disc misalignments and wrong orientations in breast IOERT: a Monte Carlo - GEANT4 and experimental study.

One of the most relevant risks in breast intraoperative electron radiotherapy (IOERT) is the incorrect positioning of the shielding disc. If such a setup error occurs, the treatment zone could receive a nonuniform dose delivery, and a considerable part of the electron beam could hit - and irradiate - the patient's healthy tissue. However misalignment and tilt angle of the shielding disc can be evaluated, but it is not possible to measure the corresponding in vivo dose distribution. This led us to develop a simulation using the Geant4 Monte Carlo toolkit to study the effects of disc configuration on dose distribution. Some parameters were investigated: the shielding factor (SF), the radiation back scattering factor (BSF), the volume-dose histogram in the treatment zone, and the maximum leakage dose (MLD) in normal tissue. A lateral shift of the disc (in the plane perpendicular to the beam axis) causes a decrease in SF (from 4% for a misalignment of 5 mm to 40% for a misalignment of 40 mm), but no relevant dose variations were found for a tilt angle until 10°. In the same uncorrected disc positions, the BSF shows no significant change. MLD rises to 3.45 Gy for a 14 mm misalignment and 4.60 Gy for 30° tilt angle when the prescribed dose is 21 Gy. The simulation results are compared with the experimental ones, and allow an a posteriori estimation of the dose distribution in the breast target and underlying healthy tissue. This information could help the surgical team choose a more correct clinical setup, and assist in quantifying the degree of success or failure of an IOERT breast treatment.

Review and uses of stereotactic body radiation therapy for oligometastases.

In patients with proven distant metastases from solid tumors, it has been a notion that the condition is incurable, warranting palliative care only. The term "oligometastases" was coined to refer to isolated sites of metastasis, whereby the entire burden of disease can be recognized as a finite number of discrete lesions that can be potentially cured with local therapies. Stereotactic body radiation therapy (SBRT) is a novel treatment modality in radiation oncology that delivers a very high dose of radiation to the tumor target with high precision using single or a small number of fractions. SBRT is the result of technological advances in patient and tumor immobilization, image guidance, and treatment planning and delivery. A number of studies, both retrospective and prospective, showed promising results in terms of local tumor control and, in a limited subset of patients, of survival. This article reviews the radiobiologic, technical, and clinical aspects of SBRT for various anatomical sites.

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.

Modeling set-up error by daily MVCT for prostate adjuvant treatment delivered in 20 fractions: Implications for the assessment of the optimal correction strategies.

PURPOSE: To optimise image-guided radiotherapy (IGRT) approaches in set-up error correction for hypofractionated adjuvant treatment of prostate cancer using helical tomotherapy (HT). METHODS AND MATERIALS: HT unit provides megavoltage - CT (MVCT) imaging capability for daily patient set-up. The intrinsic uncertainty of the available image registration techniques was first investigated on a pelvic phantom. To optimise different set-up correction strategies, MVCT data of 37 patients treated with 58 Gy delivered in 20 fractions were analyzed. 620 MVCT images were globally available for the analysis. Daily on-line set-up correction without any action level was applied for 27/37 patients. The residual and the effective set-up error were assessed. For 10/37 patients an off-line correction strategy with an action level was applied. RESULTS: Phantom measurements showed an intrinsic uncertainty in MVCT imaging and registration around 0.6 mm (+/-0.5 mm) for each of the three main axes. The minimum value of the residual systematic error was found at 7th-10th session, with values between 0.7 and 1.1 mm (1 SD); a systematic residual error <2 mm for all directions was in any case found at 3rd-4th session. This result was also confirmed by the effective systematic set-up error analysis, with a minimum value within 1.5mm nearly at the 4th or 5th fraction. CONCLUSIONS: Although the minimum systematic residual error is reached at 7th-10th treatment session, the effective systematic set-up error analysis confirmed that an off-line correction at the 4th fraction without any action level may be a robust compromise with a large sparing of time and resources compared to on-line correction.