Is concomitant treatment with steroids and radiotherapy more favorable than sequential treatment in moderate-to-severe graves orbitopathy?

PURPOSE: Glucocorticoids (GCs) and external radiotherapy (RT) are used for treating moderate-to-severe Graves' orbitopathy (GO). We aimed to assess whether GCs and RT were more effective when administered concomitantly or sequentially. METHODS: We retrospectively analyzed clinical outcomes [assessed by Clinical Activity Score (CAS) and NOSPECS classification] in 73 patients treated with both i.v. GCs and RT. The patients were divided in two groups: In group A (53 patients), RT was delivered concomitantly with GCs, and in group B (20 patients) RT was administered subsequently to the end of methylprednisolone. RESULTS: At baseline, CAS (median 4.0) and the percentage of patients encompassing the various grades of the classes 2, 3 and 4 of the NOSPECS score were similar in both groups. Six months after RT, CAS decreased to 2 in both groups (p = 0.0003 vs baseline) as well as NOSPECS class 4 (p < 0.0001 vs baseline). NOSPECS class 2 improved more in group A than in group B (p = 0.016). The median cumulative dose of GCs was lower in group A than in group B (median 4.500 vs 6000 mg, p < 0.007); the overall length of therapy was shorter in group A than in group B (68 vs 106 days, p < 0,02). The most common acute adverse effect was transient conjunctivitis (five in group A and three in group B); seven patients (five in group A and two in group B, age between 60 and 66 years) developed cataract, requiring surgery in five cases. CONCLUSIONS: Concomitant administration of GC and RT showed a favorable effect in moderate-to-severe GO, thus suggesting that RT should be carried out early during steroid therapy, when clinical symptoms do not improve or deteriorate after the first i.v. administrations of GCs.

Heterotopic ossifications: role of radiotherapy as prophylactic treatment.

BACKGROUND: Heterotopic ossification (HO) is abnormal formation of lamellar bone in soft tissue; the most frequent causes are total hip arthroplasty and trauma. Severe cases can lead to ankilosis with important impact on quality of life. Surgery is the elective treatment, but, especially in high-risk patients, it is important to prevent the re-formation of HO and, in these cases, radiotherapy (RT) can play an important role. MATERIALS AND METHODS: we retrospectively analyzed a mono-institutional casistic of 30 patients (31 sites) at high risk for HO development, treated with surgery and pre- or postoperative RT. The majority of patients received a single RT fraction of 7 Gy, median age was 62, with a prevalence of male and hip as most frequently involved site. Radiological studies and clinical examination were performed in all patients during the follow-up period to evaluate both treatment efficacy and acute or late toxicity. RESULTS: With a median follow up of 67 months, 23 patients had a complete response (CR) with excellent results in term of joint mobility. Two patients with CR showed a relapse of HO in the same site 19 and 12 months after treatment, respectively. Seven patients (22,6%) had a partial response (PR) to RT. One patient who reached CR had a history of previous irradiation in the same site 16 years before. No acute or late reactions have been reported. CONCLUSION: Our data confirm safety and efficacy of RT in preventing HO, especially in high-risk patients, preferring a single fraction of 7 Gy.

Low-dose radiotherapy for extranodal marginal zone B lymphoma of the lip: Case report and literature review.

Non-Hodgkin lymphoma (NHL) of the lip is extremely rare. It is usually indolent and in early stages a local approach is often indicated. We present a case report of a patient with extranodal NHL of the lip treated with chemotherapy and low-dose radiation treatment (RT). The patient was affected by B-cell NHL of the marginal zone, Stage IAE. After a few months of observation with progressive disease, the patient was submitted to two cycles of chemotherapy with no response. Therefore, he was treated with very low-dose RT consisting of two fractions of 2 Gy. Complete response was observed and after 1-year follow-up, persistent complete response was recorded. In cases of localized disease, especially in patients with comorbidities of poor performance status (PS), low-dose RT can be an appropriate approach with excellent outcomes in terms of effectiveness and low risk of toxicity.

The influence of small field output factors simulated uncertainties on the calculated dose in VMAT plans for brain metastases: a multicentre study.

OBJECTIVES: This multicentric study was carried out to investigate the impact of small field output factors (OFs) inaccuracies on the calculated dose in volumetric arctherapy (VMAT) radiosurgery brain plans. METHODS: Nine centres, realised the same five VMAT plans with common planning rules and their specific clinical equipment Linac/treatment planning system commissioned with their OFs measured values (OFbaseline). In order to simulate OFs errors, two new OFs sets were generated for each centre by changing only the OFs values of the smallest field sizes (from 3.2 × 3.2 cm2 to 1 × 1 cm2) with well-defined amounts (positive and negative). Consequently, two virtual machines for each centre were recommissioned using the new OFs and the percentage dose differences ΔD (%) between the baseline plans and the same plans recalculated using the incremented (OFup) and decremented (OFdown) values were evaluated. The ΔD (%) were analysed in terms of planning target volume (PTV) coverage and organs at risk (OARs) sparing at selected dose/volume points. RESULTS: The plans recalculated with OFdown sets resulted in higher variation of doses than baseline within 1.6 and 3.4% to PTVs and OARs respectively; while the plans with OFup sets resulted in lower variation within 1.3% to both PTVs and OARs. Our analysis highlights that OFs variations affect calculated dose depending on the algorithm and on the delivery mode (field jaw/MLC-defined). The Monte Carlo (MC) algorithm resulted significantly more sensitive to OFs variations than all of the other algorithms. CONCLUSION: The aim of our study was to evaluate how small fields OFs inaccuracies can affect the dose calculation in VMAT brain radiosurgery treatments plans. It was observed that simulated OFs errors, return dosimetric calculation accuracies within the 3% between concurrent plans analysed in terms of percentage dose differences at selected dose/volume points of the PTV coverage and OARs sparing. ADVANCES IN KNOWLEDGE: First multicentre study involving different Planning/Linacs about undetectable errors in commissioning output factor for small fields.

Computed Tomography to Cone Beam Computed Tomography Deformable Image Registration for Contour Propagation Using Head and Neck, Patient-Based Computational Phantoms: A Multicenter Study.

PURPOSE: To investigate the performance of various algorithms for deformable image registration (DIR) for propagating regions of interest (ROIs) using multiple commercial platforms, from computed tomography to cone beam computed tomography (CBCT) and megavoltage computed tomography. METHODS AND MATERIALS: Fourteen institutions participated in the study using 5 commercial platforms: RayStation (RaySearch Laboratories, Stockholm, Sweden), MIM (Cleveland, OH), VelocityAI and SmartAdapt (Varian Medical Systems, Palo Alto, CA), and ABAS (Elekta AB, Stockholm, Sweden). Algorithms were tested on synthetic images generated with the ImSimQA (Oncology Systems Limited, Shrewsbury, UK) package by applying 2 specific deformation vector fields (DVF) to real head and neck patient datasets. On-board images from 3 systems were used: megavoltage computed tomography from Tomotherapy and 2 kinds of CBCT from a clinical linear accelerator. Image quality of the system was evaluated. The algorithms' accuracy was assessed by comparing the DIR-mapped ROIs returned by each center with those of the reference, using the Dice similarity coefficient and mean distance to conformity metrics. Statistical inference on the validation results was carried out to identify the prognostic factors of DIR performance. RESULTS: Analyzing 840 DIR-mapped ROIs returned by the centers, it was demonstrated that DVF intensity and image quality were significant prognostic factors of DIR performance. The accuracy of the propagated contours was generally high, and acceptable DIR performance can be obtained with lower-dose CBCT image protocols. CONCLUSIONS: The performance of the systems proved to be image quality specific, depending on the DVF type and only partially on the platforms. All systems proved to be robust against image artifacts and noise, except the demon-based software.

Automatic genetic planning for volumetric modulated arc therapy: A large multi-centre validation for prostate cancer.

PURPOSE: The first clinical genetic autoplanning algorithm (Genetic Planning Solution, GPS) was validated in ten radiotherapy centres for prostate cancer VMAT by comparison with manual planning (Manual). METHODS: Although there were large differences among centres in planning protocol, GPS was tuned with the data of a single centre and then applied everywhere without any centre-specific fine-tuning. For each centre, ten Manual plans were compared with autoGPS plans, considering dosimetric plan parameters and the Clinical Blind Score (CBS) resulting from blind clinician plan comparisons. AutoGPS plans were used as is, i.e. there was no patient-specific fine-tuning. RESULTS: For nine centres, all ten plans were clinically acceptable. In the remaining centre, only one plan was acceptable. For the 91% acceptable plans, differences between Manual and AutoGPS in target coverage were negligible. OAR doses were significantly lower in AutoGPS plans (p < 0.05); rectum D15% and Dmean were reduced by 8.1% and 17.9%, bladder D25% and Dmean by 5.9% and 10.3%. According to clinicians, 69% of the acceptable AutoGPS plans were superior to the corresponding Manual plan. In case of preferred Manual plans (31%), perceived advantages compared to autoGPS were minor. QA measurements demonstrated that autoGPS plans were deliverable. A quick configuration adjustment in the centre with unacceptable plans rendered 100% of plans acceptable. CONCLUSION: A novel, clinically applied genetic autoplanning algorithm was validated in 10 centres for in total 100 prostate cancer patients. High quality plans could be generated at different centres without centre-specific algorithm tuning.

Dosimetric characterization and behaviour in small X-ray fields of a microchamber and a plastic scintillator detector.

OBJECTIVE: The aim of this work was to investigate the main dosimetric characteristics and the performance of an A26 Exradin ionization microchamber (A26 IC) and a W1 Exradin plastic scintillation detector (W1 PSD) in small photon beam dosimetry for treatment planning system commissioning and quality assurance programme. METHODS: Detector characterization measurements (short-term stability, dose linearity, angular dependence and energy dependence) were performed in water for field sizes up to 10 × 10 cm2. Polarity effect (Ppol) was examined for the A26 IC. The behaviour of the detectors in small field relative dosimetry [percentage depth dose, dose profiles often called the off-axis ratio and output factors (OFs)] was investigated for field sizes ranging from 1 × 1 to 3 × 3 cm2. RESULTS: Results were compared with those obtained with other detectors we already use for small photon beam dosimetry. A26 IC and W1 PSD showed a linear dose response. While the A26 IC showed no energy dependence, the W1 PSD showed energy dependence within 2%; no angular dependence was registered. Ppol values for A26 IC were below 0.9% (0.5% for field size >2 × 2 cm2). A26 IC and W1 PSD depth-dose curves and lateral profiles agreed with those obtained with an EDGE diode. No differences were observed among the detectors in OF measurement for field sizes larger than 1 × 1 cm2, with average differences <1%. For field sizes <1 × 1 cm2, the effective volume of ionization chamber and non-water equivalence of EDGE diode become significant. A26 IC OF values were significantly lower than EDGE diode and W1 PSD values, with percentage differences of about -23 and -13% for the smallest field, respectively. W1 PSD OF values lay between ion chambers and diode values, with a maximum percentage difference of about -10% with respect to the EDGE diode, for a 6 × 6-mm2 field size. CONCLUSION: The results of our investigation confirm that A26 IC and W1 PSD could play an important role in small field relative dosimetry. Advances in knowledge: Dosimetric characteristics of Exradin A26 ionization microchamber and W1 plastic scintillation detector for small field dosimetry.

Dosimetric evaluation of two radiotherapy treatment planning systems using report 55 by the AAPM task group 23.

The AAPM Report 55 of Task Group 23 (TG23) is used to verify the accuracy of the calculation algorithm of two radiotherapic treatment planning systems (TPS), which use two pencil beam models (one of the last generation) and a collapsed cone convolution model. The basic feature of TG23 is that it compares dose values computed by TPS and experimental dose measures in situations that reproduce those of simple radiotherapeutic treatments. A threshold of 2% was considered for discrepancies between computed and measured values. The results gave a good accuracy of considered algorithms, except for those points in high dose gradient regions, for which the evaluation as a percentage difference, rather than in millimeters, may overestimate the discrepancies. It was seen that the TG23 package is not only an algorithm verification method, but also a useful instrument for training with dosimetry, configuration and application of a TPS.