Bronchial wall parameters on CT in healthy never-smoking, smoking, COPD, and asthma populations:a systematic review and meta-analysis

OBJECTIVE: Research on computed tomography (CT) bronchial parameter measurements shows that there are conflicting results on the values for bronchial parameters in the never-smoking, smoking, asthma, and chronic obstructive pulmonary disease (COPD) populations. This review assesses the current CT methods for obtaining bronchial wall parameters and their comparison between populations. METHODS: A systematic review of MEDLINE and Embase was conducted following PRISMA guidelines (last search date 25th October 2021). Methodology data was collected and summarised. Values of percentage wall area (WA%), wall thickness (WT), summary airway measure (Pi10), and luminal area (Ai) were pooled and compared between populations. RESULTS: A total of 169 articles were included for methodologic review; 66 of these were included for meta-analysis. Most measurements were obtained from multiplanar reconstructions of segmented airways (93 of 169 articles), using various tools and algorithms; third generation airways in the upper and lower lobes were most frequently studied. COPD (12,746) and smoking (15,092) populations were largest across studies and mostly consisted of men (median 64.4%, IQR 61.5 - 66.1%). There were significant differences between populations; the largest WA% was found in COPD (mean SD 62.93 ± 7.41%, n = 6,045), and the asthma population had the largest Pi10 (4.03 ± 0.27 mm, n = 442). Ai normalised to body surface area (Ai/BSA) (12.46 ± 4 mm2, n = 134) was largest in the never-smoking population. CONCLUSIONS: Studies on CT-derived bronchial parameter measurements are heterogenous in methodology and population, resulting in challenges to compare outcomes between studies. Significant differences between populations exist for several parameters, most notably in the wall area percentage; however, there is a large overlap in their ranges. KEY POINTS: • Diverse methodology in measuring airways contributes to overlap in ranges of bronchial parameters among the never-smoking, smoking, COPD, and asthma populations. • The combined number of never-smoking participants in studies is low, limiting insight into this population and the impact of participant characteristics on bronchial parameters. • Wall area percent of the right upper lobe apical segment is the most studied (87 articles) and differentiates all except smoking vs asthma populations

Hyperthermia dose-effect relationship in 420 patients with cervical cancer treated with combined radiotherapy and hyperthermia

Adding hyperthermia to standard radiotherapy (RT + HT) improves treatment outcome for patients with locally advanced cervical cancer (LACC). We investigated the effect of hyperthermia dose on treatment outcome for patients with LACC treated with RT + HT. We collected treatment and outcome data of 420 patients with LACC treated with hyperthermia at our institute from 1990 to 2005. Univariate and multivariate analyses were performed on response rate, local control, disease-specific survival and toxicity for these patients to search for a thermal dose response relationship. Besides commonly identified prognostic factors in LACC like tumour stage, performance status, radiotherapy dose and tumour size, thermal parameters involving both temperature and duration of heating emerged as significant predictors of the various end-points. The more commonly used CEM43T90 (cumulative equivalent minutes of T90 above 43 degrees C) was less influential than TRISE (based on the average T50 increase and the duration of heating, normalised to the scheduled duration of treatment). CEM43T90 and TRISE measured intraluminally correlate significantly and independently with tumour control and survival. These findings stimulate further technological development and improvement of deep hyperthermia, as they strongly suggest that it might be worthwhile to increase the thermal dose for LACC, either by treatment optimisation or by prolonging the treatment time. These results also confirm the beneficial effects from hyperthermia as demonstrated in our earlier randomised trial, and justify applying radiotherapy and hyperthermia as treatment of choice for patients with advanced cervical cancer. (c) 2009 Elsevier Ltd. All rights reserved

Quality Assurance of Superficial Hyperthermia Treatments Superficial Hyperthermia Treatments

In hyperthermia, tumour-loaded tissue is heated to a supraphysiological level of 40-45 °C. Hyperthermia is a well-established adjuvant to radiotherapy and/or chemotherapy. Hyperthermia causes direct cytotoxicity and has effect on tumour blood flow and oxygenation, which may enhance the other treatment modality. Further, hyperthermia sensitizes cells to both radiotherapy and chemotherapy, among other things by inhibition of DNA repair processes. The efficacy of hyperthermia has been demonstrated in randomized trials for multiple cancer types [1-18]. Several heating techniques and devices exist to heat tumours at different sites: deepregional and part-body hyperthermia, local hyperthermia, interstitial and endocavitary hyperthermia, and whole body hyperthermia [19]. The Erasmus MC – Daniel den Hoed Cancer Center has three treatment modes available, all of which use electromagnetic waves to heat tissue. Tumours in the pelvic region (deep hyperthermia) can be heated using the BSD-2000 system (BSD Medical, USA). The in-house developed Lucite cone applicator system can heat tumours at the body surface (superficial hyperthermia). Recently, also a specific system has been developed to heat tumours in the head and neck region [20]. The scope of this thesis is limited to superficial hyperthermia (SHT). Therefore, the next sections will focus on the clinical context and quality assurance of SHT treatments

Quality control of superficial hyperthermia by treatment evaluation

Steering of multi-element heating arrays for superficial hyperthermia (SHT) can be a challenge in the clinic. This is because the technician has to deal with a multiple-input multiple-output system, varying tissue dynamics, and often sparse tissue temperature data. In addition, patient feedback needs to be taken into account. Effective management of the steering task determines the quality of heating. Systematic evaluation is an effective tool to control the quality of treatments. The purpose of this manuscript is to report on a treatment evaluation flow developed for SHT at the Erasmus MC. This flow is used to secure the quality of steering as well as to stimulate general quality awareness in the hyperthermia team. All treatments are evaluated in a multidisciplinary discussion. Tools and methods were developed to enable effective and efficient evaluations. The treatment evaluation sheet is a compact and intuitive representation of power and temperature data. Trend lines and a temperature-depth plot allow a quick analysis of the steering parameters and the heating profile within the target volume. In addition, the principal statistics of applicator power, water bolus and tissue temperature values are given. Power steering data includes the number of switch-off events, interruption time and the number of steering actions. A list of basic checks and reference values for clinical data support further the treatment evaluation. These tools and the systematic treatment evaluations they facilitate, ultimately lead to consistent performance and fine tuning of the set-up and steering strategy for each individual patient

Evaluation of CEM43 degrees CT90 Thermal Dose in Superficial Hyperthermia

Background and Purpose: Prospective use of the CEM43 degrees CT90 thermal dose parameter has been proposed for hyperthermia treatments. This study evaluates the CEM43 degrees CT90 parameter by means of a retrospective analysis of recurrent breast cancer patients receiving reirradiation plus hyperthermia. Material and Methods: CEM43 degrees CT90 was calculated for 72 patients who received 8 x 4 Gy reirradiation plus 8 x 1 h hyperthermia for adenocarcinoma recurrences at the chest wall. Associations of prognostic factors CEM43 degrees CT90 and tumor maximum diameter with endpoints complete response (CR), duration of local control (DLC), and overall survival (OS) were determined. Results: A highly significant inverse association between CEM43 degrees CT90 and tumor maximum diameter (p = -0.7, p = 0.7). CEM43 degrees CT90 was associated with DLC. Both CEM43 degrees CT90 and tumor maximum diameter had a significant association with survival (p 0.2). Conclusion: In this retrospective study, no clear CEM43 degrees CT90 thermal dose targets or associations with clinical endpoints could be established

RF-power and temperature data analysis of 444 patients with primary cervical cancer: Deep hyperthermia using the Sigma-60 applicator is reproducible

Treatment reproducibility is important to guarantee reproducible treatment-outcome, a low-complication rate and efficient treatment procedures. This study evaluated the performance of loco-regional deep hyperthermia with four BSD-2000 configurations during 1990-2005 using the direct available parameters, i.e., temperature and power. Primary cervical cancer patients (n = 444) were all treated within the Sigma-60. Patients were grouped in three weight-groups: 70 kg. Different temperature and power indices were extensively analyzed per BSD configuration, per weight-group, and over the time-period. No substantial variations were found for temperature/power indices over the four BSD configurations or for the temperature doses in similar weight-groups. The `bare' power indices were increased with weight; however, the derivative power-related (W/kg, W/cm(2)) and temperature indices decreased. Large variations were found in the power-related parameters during 1991-1996 (1st time-period), whereas they were much smaller during 1997-2005 (2nd time-period). The most relevant change noted was the adaptation of the treatment strategy with respect to power modulation. The average frequency of switched-off was 3.4 and 8.9 times/treatment session for the 1st and 2nd time-period, respectively, while the average duration of each switched-off time was 78.2 vs. 38.3 s. The yearly average of vagina T-50 was in the range of 39.3-40.2 degrees C (1st time-period) and 40.0-40.5 degrees C (2nd time-period). In 40% of the patients, a positive correlation was found between normalized net integrated power per pelvic area and vagina T50. Good reproducible heating is achieved with the BSD-2000 Sigma-60 irrespective of the regular technological upgrades of the system and variation of trained staff-members