Centro Médico Bustos Fernandez

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma. About 40% of patients present with localized disease at diagnosis. In the randomized FLYER trial, patients with stage I and II disease and favorable prognosis had the same 5-year progression-free survival (PFS) and overall survival (OS) with 4 cycles of R-CHOP plus 2 cycles of Rituximab monotherapy as those treated with 6 cycles of R-CHOP. This present study proposes the first Argentinian registry for a standardized treatment evaluating the efficacy and safety of a shortened treatment regimen guided by PET-CT response in DLBCL patients with stage I and II without adverse prognostic factors. PET-CT parameters will be analised as potential prognostic factors. Objectives: Evaluate 3-year PFS and OS in stage I–II DLBCL patients treated with PET-CT-guided therapy. Assess prognostic factors for PFS in localized DLBCL, IPI 0. Determine the prognostic value of PET-CT, including baseline MTV, TLG, and ∆SUVmax in interim PET-CT. Materials and Methods: A prospective, multicenter study by the Argentinian GATLA group. Patients ≥ 17 years, with de novo DLBCL, stage I–II, and IPI 0 were included. All underwent baseline PET-CT and received 3 cycles of R-CHOP. An interim PET-CT was performed on days 15–18 of the third cycle, centrally reviewed by three centers. PET-CT negative (DS 1–3): One additional R-CHOP cycle, then treatment ends. PET-CT DS 4: One additional cycle + 36 Gy radiotherapy. PET-CT DS 5: Exclusion. Results: Since November 2021, 21 patients from 6 centers were included (12 men, 9 women, median age 58 years). All had histopathologically confirmed DLBCL. By Hans’ algorithm, 12 were germinal center subtype; 2 were double expressors, and 11 (52%) had Ki67 > 80%. Seven had stage I and 14 stage II. Eleven had supradiaphragmatic nodal involvement, 4 infradiaphragmatic, and 6 extranodal. Median baseline PET-CT values: MTV 16 (0–217), TLG 87 (0–4046), SUVmax 9 (2–42). All achieved negative interim PET-CT; none required radiotherapy. With a median follow-up of 27 months, only one relapse occurred, and one patient died from infection in remission. Conclusions: Our findings support the safety and efficacy of a PET-CT–adapted approach to reduce the number of treatment cycles in patients with localized stage I–II DLBCL and no adverse prognostic factors, aligning with previously published data. However, recruiting these patients remains a significant challenge due to the low incidence of this presentation. While our current results confirm the effectiveness of a shortened treatment strategy, a larger number of patients is needed to determine the prognostic value of baseline and interim PET-CT parameters. Patient enrolment is ongoing to strengthen these findings and explore additional prognostic factors. Research funding declaration: None Keywords: PET-CT; aggressive B-cell non-Hodgkin lymphoma; ongoing trials No potential sources of conflict of interest.

Objective:The aim of this study was to evaluate theclinical, radiological, and survivorship results of a porous-coated uncemented acetabularcup (Novation Crowncup TM Exactech, Gainesville, Florida, USA) in patientsundergoing total hip arthroplasty at the mid to long term follow-up.Methods:We prospectively analyzed 185 consecutivetotal hip replacements in 176 patients during 2009. All the patients received aNovation Crowncup™ uncemented cup. All surgeries were performed by one ofthe 4 joint replacement specialists. Several clinical and radiographic outcomemeasures were evaluated.Results:There was no cupmigration recorded. Six cups (5.2%) had a thin (less than 1 mm) radiolucentline without signs of loosening or clinical manifestation, but under close followup. The wear was not significative at the end of the follow up. The mean HarrisHip Score increased from 45.7 (range = 28 to 65) preoperatively to 89.8 (range= 87 to 96) at the final follow-up. Subjectiveevaluation showed excellent results in 82.6%, good in 8.6%, fair in 5.9%, andpoor in 2.9% of the cases. Eight patients, 3 stems, and 5 cups (5% of the series)were revised, the survival of the series was 95% when the failure was the needfor additional acetabular or femoral revision surgery for any reason. If wedefine failure as the need for an acetabular revision for some reason, thesurvival was (97.5%). When we evaluated survival only for aseptic loosening ofthe cup at 10 years of follow-up, 98.4% of the implants survived.Conclusion:In our series,when we evaluated survival only for aseptic loosening of the cup at 10 years offollow-up, 98.4% of the implants survived. The Crowncup acetabular cup survivalrate was 97.5% including all causes of loosening and 95% including all causesfor revision at 10 years of follow-up.Level of Evidence:Level IV, Therapeutic Study

A 7-year-old girl presented with a 2-day history of left ankle pain and swelling that started with limping. On the first day of symptoms, she was evaluated in other institutions Emergency Department (ED) presenting pain during walking without trauma history. Radiographic examination was normal and she was discharged home on Ibuprofen 10 ml/8 hours.

Purpose: To validate a recently installed portal dosimetry system that uses an in-house developed analysis application for IMRT QAMethods: 6 MV X-ray Intensity modulated radiation therapy fields were delivered by a Varian 6EX linear accelerator (Varian Associates, Palo Alto, CA, USA) equipped with Millennium 120 multileaf collimator. An aS1000 Portal Vision electronic portal imaging device (EPID) was installed on the accelerator. In-house gamma analysis software was designed to compare the dosimetryc distributions predicted by the XiO 4.50 treatment planning system (Elekta, Stockholm, Sweden) and those measured by the EPID system. The EPID was calibrated in absolute dose following the vendor recommended procedure. IMRT fields were acquired at a source to detector distance of 105 cm. To validate the results of the in-house software the same IMRT fields were also acquired using a commercial 2D array of 445 n-type diodes system arranged in a 22 cm side cm2 area subdivided in two density regions. A central 10 cm side region containing 221 diodes spaced 7.07 mm and an outer region containing 221 diodes spaced 14.14 mm. Gamma distribution map and percentage of points with gamma <1 using a 3% 3mm criterion were used in both cases as QA pass/fail criteria. Results: For one given field, gamma distribution maps of both detectors were similar in the inner region of the field but EPID based images showed more discrepancies in the borders of the fields due to higher resolution of the EPID panel. Percentage of points with gamma < 1 was between 97.2 and 99.7 for EPID images and between 96.0 and 100% for 2D diode array. Conclusion: The software developed ad hoc for EPID based IMRT QA proved to be a valuable and affordable solution. Similar results confirm soundness of the analysis performed by the software and validates its clinical use.