Using the gamma-index analysis for inter-fractional comparison of in-beam PET images for head-and-neck treatment monitoring in proton therapy: A Monte Carlo simulation study.

GOAL: In-beam Positron Emission Tomography (PET) is a technique for in-vivo non-invasive treatment monitoring for proton therapy. To detect anatomical changes in patients with PET, various analysis methods exist, but their clinical interpretation is problematic. The goal of this work is to investigate whether the gamma-index analysis, widely used for dose comparisons, is an appropriate tool for comparing in-beam PET distributions. Focusing on a head-and-neck patient, we investigate whether the gamma-index map and the passing rate are sensitive to progressive anatomical changes. METHODS/MATERIALS: We simulated a treatment course of a proton therapy patient using FLUKA Monte Carlo simulations. Gradual emptying of the sinonasal cavity was modeled through a series of artificially modified CT scans. The in-beam PET activity distributions from three fields were evaluated, simulating a planar dual head geometry. We applied the 3D-gamma evaluation method to compare the PET images with a reference image without changes. Various tolerance criteria and parameters were tested, and results were compared to the CT-scans. RESULTS: Based on 210 MC simulations we identified appropriate parameters for the gamma-index analysis. Tolerance values of 3 mm/3% and 2 mm/2% were suited for comparison of simulated in-beam PET distributions. The gamma passing rate decreased with increasing volume change for all fields. CONCLUSION: The gamma-index analysis was found to be a useful tool for comparing simulated in-beam PET images, sensitive to sinonasal cavity emptying. Monitoring the gamma passing rate behavior over the treatment course is useful to detect anatomical changes occurring during the treatment course.

In-beam PET treatment monitoring of carbon therapy patients: Results of a clinical trial at CNAO.

PURPOSE: Carbon ion therapy treatments can be monitored non-invasively with in-beam Positron Emission Tomography (PET). At CNAO the INSIDE in-beam PET scanner has been used in a clinical trial (NCT03662373) to monitor cancer treatments with proton and carbon therapy. In this work we present the analysis results of carbon therapy data, acquired during the first phase of the clinical trial, analyzing data of nine patients treated at CNAO for various malignant tumors in the head-and-neck region. MATERIALS AND METHODS: The patient group contained two patients requiring replanning, and seven patients without replanning, based on established protocols. For each patient the PET images acquired along the course of treatment were compared with a reference, applying two analysis methods: the beam-eye-view (BEV) method and the γ-index analysis. Time trends in several parameters were investigated, as well as the agreement with control CTs, if available. RESULTS: Regarding the BEV-method, the average sigma value σ was 3.7 mm of range difference distributions for patients without changes (sensitivity of the INSIDE detector). The 3D-information obtained from the BEV analysis was partly in agreement with what was observed in the control CT. The data quality and quantity was insufficient for a definite interpretation of the time trends. CONCLUSION: We analyzed carbon therapy data acquired with the INSIDE in-beam PET detector using two analysis methods. The data allowed to evaluate sensitivity of the INSIDE detector for carbon therapy and to make several recommendations for the future.

Atividade preemptiva da infiltração da incisão com ropivacaína a 0,75%, em pacientes submetidos à herniorrafia inguinal / Preemptive activity of incision infiltration with 0.75% ropivacaine in patients submitted to inguinal hernia repair

JUSTIFICATIVA E OBJETIVOS: A eficiência da analgesia preemptiva em relação ao regime convencional no controle da dor pós-operatória continua a ser controversa. O objetivo deste estudo foi avaliar a eficácia da infiltração local com ropivacaína a 0,75% antes e depois da incisão em operações de herniorrafia inguinal na intensidade da dor pós-operatória, no consumo de analgésicos e no tempo para solicitação da primeira dose de analgésico.MÉTODO: Após a aprovação pelo Comitê de Ética em Pesquisa Institucional, 60 pacientes, estado físico P1 ou P2, com idade entre 15 e 65 anos, submetidos à herniorrafia inguinal sob anestesia geral com isoflurano e fentanil foram distribuídos aleatoriamente em três grupos: A - infiltração da pele, subcutâneo e tecido muscular antes da incisão com 2 mg/kg de ropivacaína a 0,75%; D - infiltração da pele, subcutâneo e tecido muscular após incisão com 2 mg/kg de ropivacaína a 0,75%; e o C - grupo controle - sem infiltração. Todos os pacientes receberam dipirona (2 g), 30 minutos antes do final da anestesia. Uma bomba de analgesia controlada pelo paciente com morfina foi usada depois da recuperação da anestesia. Foram avaliados durante 24 horas a intensidade da dor com a escala analógica visual, o consumo total de morfina e o tempo para a solicitação da primeira dose de morfina. RESULTADOS: O consumo de morfina foi significativamente menor no grupo A (1,5 mg) quando comparado ao grupo D de (5,5 mg) ou controle (17 mg). O tempo para a solicitação da primeira dose de morfina foi significativamente maior para o grupo A assim como a intensidade da dor em todos os momentos quando comparado ao grupo C e nas últimas 18 h comparado ao grupo.CONCLUSÃO: A infiltração pré-operatória da incisão com ropivacaína reduz significativamente a intensidade da dor e o consumo de morfina pós-operatória e retarda o tempo para a solicitação da primeira dose de morfina.

BACKGROUND AND OBJECTIVES: The effectiveness of preemptive analgesia as compared to the conventional regimen for postoperative pain control is still controversial. This study aimed at evaluating the effectiveness of local infiltration with 0.75% ropivacaine before and after the incision of inguinal hernia repair surgeries in postoperative pain intensity, analgesics consumption and time elapsed for first analgesic dose request. METHOD: After the Institutional Research Ethics Committee approval, 60 patients, physical status P1 or P2, aged between 15 and 65 years, submitted to inguinal hernia repair under general anesthesia with isoflurane and fentanyl were randomly distributed in three groups: A - skin, subcutaneous and muscle infiltration before incision with 2 mg/kg of 0.75% ropivacaine; D - skin, subcutaneous and muscle infiltration after incision with 2 mg/kg of 0.75% ropivacaine; and C - control group, without infiltration. All patients received dipirone (2 g), 30 minutes before the end of anesthesia.A patient-controlled analgesia pump with morphine was used after anesthetic recovery. Pain intensity with visual analog scale, total morphine consumption and time for the first morphine dose request were evaluated during 24 hours.RESULTS: Morphine consumption was significantly lower in the A group (1.5 mg) as compared to the D group (5.5 mg) or to the control group (17 mg). Time for first morphine dose request was significantly longer for the A group and pain intensity was lower in all moments as compared to C group and in the last 18 h as compared to the group.CONCLUSION: Preoperative incision infiltration with ropivacaine significantly decreases postoperative pain intensity and morphine consumption and delays the time for first morphine dose request.

Evaluation of ketorolac compared to ketorolacplus dipyrone in post-operative analgesiaof videolaparoscopic cholecystectomy / Avaliação do efeito da dipirona associada ao cetorolaco comparado ao cetorolaco em pós-operatório de colecistectomia videolaparoscópica

Objectives: To compare the analgesic effect of ketorolac with the association of ketorolac plus dipyrone after videolaparoscpic cholecystectomy and with a placebo group. Methods: After approval by the Research Ethics Committee and after having the informed consent signed, 60 patients aged between 18 and 60 years who underwent videolaparoscopic cholecystectomy were evaluated for the post-operative analgesia provided by ketorolac compared to ketorolac plus dipyrone. The patients underwent general anesthesia (with propofol, alfentanil, rocuronium and maintenance with isoflurane). Twenty patients received 20 ml water, 20 patients received ketorolac 30 mg in 20 ml water and 20 received ketorolac 30 mg plus dipyrone 2 g in 20 ml water, during anesthetic induction. In the post-operative recovery room, the patients were evaluated to the moment of their first pain complaint with the use of a visual analogue scale and a verbal pain scale every hour in the first six hours. When necessary, morphine was administered as a rescue medication for pain relief and a PCA pump with morphine solution was turned on. Results: Total morphine use was lower in the ketorolac plus dipyrone Group (2 mg) and in the ketorolac (2 mg) Group, compared to the placebo Group (10.5 mg). Of 20 cases of ketorolac plus dipyrone, eight patients did not complain of pain in the post-operative period, while only three patients did not complain in the ketorolac Group and in the placebo Group (p = 0,05). Conclusion: Ketorolac is a potent analgesic agent widely used for acute pain treatment, especially after surgeries, with an analgesic potency comparable to that of opiates, the most commonly drugs used during the post-operative of medium to major surgeries. In this study, the results analyzed at this moment show that the association of ketorolac plus dipyrone seemed to be superior to post-operative analgesia compared to the use of ketorolac.

Objetivos: Comparar o efeito analgésico do cetorolaco e da associação cetorolaco mais dipirona após cirurgias de colecistectomias videolaparoscópicas. Métodos: Após a aprovação do Comitê de Ética e a obtenção do consentimento informado, 60 pacientes com idade entre 18 a 60 anos e candidatos à colecistectomia videolaparoscópica, foram submetidos ao procedimento cirúrgico sob anestesia geral balanceada com propofol, alfentanil, rocurônio e manutenção com isoflurano. Foram divididos em três grupos: placebo, recebendo 20 ml de solução salina; cetorolaco com 30 mg de cetorolaco em 20 ml de solução salina; e cetorolaco mais dipirona, recebendo 30 mg de cetorolaco e 2 g de dipirona em 20 ml de solução salina. Os fármacos foram aplicados por via venosa, no início da incisão cirúrgica. Na sala de recuperação pós-anestésica os pacientes foram avaliados, quanto ao momento da primeira queixa dolorosa pela escala visual analógica e verbal e grau de sedação, a cada hora nas primeiras seis horas. Se necessário era utilizada como medicação de resgate, morfina administrada por bomba de analgesia controlada pelo paciente. Resultados: O consumo total de morfina no pós-operatório foi menor no Grupo cetorolaco mais dipirona (2 mg) e no Grupo cetorolaco (2 mg) comparado ao Grupo placebo (10,5 mg) com p = 0,10. No Grupo cetorolaco mais dipirona, oito pacientes não referiram dor no pós-operatório, enquanto que apenas três no Grupo cetorolaco e três no Grupo placebo não se queixaram de dor (p = 0,05, teste do χ2). Conclusão: O cetorolaco tem sido amplamente utilizado no tratamento da dor aguda, especialmente a pós-operatória, principalmente em cirurgias de médio e grande porte, isoladas ou associadas aos opioides. No presente estudo, a associação de cetorolaco com dipirona se mostrou superior na analgesia após colecistectomias videolaparoscópicas quando comparada ao cetorolaco.