Thermal dosimetry for bladder hyperthermia treatment. An overview.

The urinary bladder is a fluid-filled organ. This makes, on the one hand, the internal surface of the bladder wall relatively easy to heat and ensures in most cases a relatively homogeneous temperature distribution; on the other hand the variable volume, organ motion, and moving fluid cause artefacts for most non-invasive thermometry methods, and require additional efforts in planning accurate thermal treatment of bladder cancer. We give an overview of the thermometry methods currently used and investigated for hyperthermia treatments of bladder cancer, and discuss their advantages and disadvantages within the context of the specific disease (muscle-invasive or non-muscle-invasive bladder cancer) and the heating technique used. The role of treatment simulation to determine the thermal dose delivered is also discussed. Generally speaking, invasive measurement methods are more accurate than non-invasive methods, but provide more limited spatial information; therefore, a combination of both is desirable, preferably supplemented by simulations. Current efforts at research and clinical centres continue to improve non-invasive thermometry methods and the reliability of treatment planning and control software. Due to the challenges in measuring temperature across the non-stationary bladder wall and surrounding tissues, more research is needed to increase our knowledge about the penetration depth and typical heating pattern of the various hyperthermia devices, in order to further improve treatments. The ability to better determine the delivered thermal dose will enable clinicians to investigate the optimal treatment parameters, and consequentially, to give better controlled, thus even more reliable and effective, thermal treatments

The influence of multidisciplinary team meetings on treatment decisions in advanced bladder cancer

Objectives: To investigate the role of specialised genitourinary multidisciplinary team meetings (MDTMs) in decision-making and identify factors that influence the probability of receiving a treatment plan with curative intent for patients with muscle invasive bladder cancer (MIBC). Patients and methods: Data relating to patients with cT2-4aN0/X-1 M0 urothelial cell carcinoma, diagnosed between November 2017 and October 2019, were selected from the nationwide, population-based Netherlands Cancer Registry (‘BlaZIB study’). Curative treatment options were defined as radical cystectomy (RC) with or without neoadjuvant chemotherapy, chemoradiation or brachytherapy. Multilevel logistic regression analyses were used to examine the association between MDTM factors and curative treatment advice and how this advice was followed. Results: Of the 2321 patients, 2048 (88.2%) were discussed in a genitourinary MDTM. Advanced age (&gt;80 years) and poorer World Health Organization performance status (score 1–2 vs 0) were associated with no discussion (P &lt; 0.001). Being discussed was associated with undergoing treatment with curative intent (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.9–4.9), as was the involvement of a RC hospital (OR 1.70, 95% CI 1.09–2.65). Involvement of an academic centre was associated with higher rates of bladder-sparing treatment (OR 2.05, 95% CI 1.31–3.21). Patient preference was the main reason for non-adherence to treatment advice. Conclusions: For patients with MIBC, the probability of being discussed in a MDTM was associated with age, performance status and receiving treatment with curative intent, especially if a representative of a RC hospital was present. Future studies should focus on the impact of MDTM advice on survival data.</p

Development of a 27.12 MHz CC-LCF intraluminal applicator for hyperthermia of the esophagus

Esophageal tumors can be treated with radiation combined with hyperthermia. This study investigated the design of a 27.12 MHz capacitively coupled intraluminal applicator for hyperthermia of the esophagus to be used in combination with external locoregional heating. It consists of four independent electrodes mounted on an inflatable balloon catheter, 10mm each, Measured SAR penetration depth is 4.5mm. Spatial steering is excellent and will prove useful in heterogeneous tumors. Combination with locoregional heating showed a strong increase in temperature rise. Next step is application in esophageal cancer

Hyperthermia of deep seated pelvic tumors with a phased array of eight versus four 70 MHz waveguides

Hyperthermia, increasing tumor temperatures to 40-43°C for 1 h, enhances the effectiveness of radiotherapy and chemotherapy. Deep seated pelvic tumors are usually heated by arrays of radiofrequency or microwave antennas placed around the patient. During hyperthermia treatment-limiting hot spots may arise in normal tissue. The AMC-8 device with eight 70 MHz waveguides was designed to overcome this issue by improving power steering abilities compared to the four waveguide AMC-4 device. Four patients with pelvic malignancies were treated with this system. Each patient received 2-3 treatments using 4 waveguides and two treatments using 8 waveguides, all at a total power of 550W. Average steady state tumor temperatures T90 and T50 were 39.9°C and 41.3°C for 4 waveguides and 39.7°C and 41.4°C for 8 waveguides, respectively. Toxicity was minimal with a lower incidence of hot-spots for eight waveguides. The transition from 4 to 8 waveguides was associated with unchanged tumor temperatures and a reduction in hot spots. Thus higher power levels and higher tumor temperatures can be achieved with the 8 waveguide configuration

Short-Course External Beam Radiotherapy Versus Brachytherapy for Palliation of Dysphagia in Esophageal Cancer: A Matched Comparison of Two Prospective Trials

Contains fulltext : 221576.pdf (Publisher’s version ) (Open Access

Definitive chemoradiation for patients with inoperable and/or unresectable esophageal cancer: locoregional recurrence pattern

A locoregional recurrence after definitive chemoradiation (dCRT) for patients with inoperable or unresectable esophageal cancer occurs in about 50% of the patients and is a major cause of failure with a poor prognosis. The aim of this study was to determine the pattern of locoregional recurrence and its prognostic factors after dCRT in order to search for improvements in radiation treatment. We retrospectively reviewed 184 patients treated with external beam radiotherapy (50.4 Gray/28 fractions), combined with weekly concurrent paclitaxel and carboplatin. Locoregional recurrences were defined by clinical signs of recurrent or progressive disease, combined with progression on computed tomography/positron emission tomography-computed tomography scan, or suspicious endoscopic findings and/or histological proof of recurrence. The site of locoregional recurrence was analyzed with respect to the borders of the radiation fields. After a mean follow up of 22.8 months, 76 patients (41%) had evidence of locoregional recurrence. The 3-years locoregional recurrence-free rate was 45%. The majority of locoregional recurrences occurred within 12 months, nearly all within 24 months. The majority of these patients failed at the site of the primary tumor (86%). Infield locoregional recurrences at the site of the lymph nodes only occurred in 1% compared with 57% at the site of the primary tumor only. Outfield locoregional lymph node recurrences occurred in 22%, without infield recurrence occurred in only 4% of all patients. The 1-, 3-, and 5-year overall survival was 65%, 28%, and 21%, respectively. The current analysis demonstrates that a locoregional recurrence after dCRT occurs in 41% of the patients, the majority at the site of the primary tumor. These data suggest a benefit of dose intensification of the primary tumor, but not at the site of the lymph nodes. Higher radiation doses should be assessed with prospective trials

Thromboembolic and bleeding complications in patients with oesophageal cancer

Background: In patients who undergo curative treatment for oesophageal cancer, risk estimates of venous thromboembolism (VTE), arterial thromboembolism and bleeding are needed to guide decisions about thromboprophylaxis. Methods: This was a single-centre, retrospective cohort study of patients with stage I–III oesophageal cancer who received neoadjuvant chemoradiation followed by oesophagectomy. The outcomes VTE, arterial thromboembolism, major bleeding, clinically relevant non-major bleeding and mortality were analysed for four consecutive cancer treatment stages (from diagnosis to neoadjuvant chemoradiotherapy, during neoadjuvant treatment, 30-day postoperative period, and up to 6 months after postoperative period). Results: Some 511 patients were included. The 2-year survival rate was 67·3 (95 per cent c.i. 63·2 to 71·7) per cent. During the 2-year follow-up, 50 patients (9·8 per cent) developed VTE, 20 (3·9 per cent) arterial thromboembolism, 21 (4·1 per cent) major bleeding and 30 (5·9 per cent) clinically relevant non-major bleeding. The risk of these events was substantial at all treatment stages. Despite 30-day postoperative thromboprophylaxis, 17 patients (3·3 per cent) developed VTE after surgery. Patients with VTE had worse survival (time-varying hazard ratio 1·81, 95 per cent c.i. 1·25 to 2·64). Most bleeding events occurred around the time of medical intervention, and approximately one-half during concomitant use of prophylactic or therapeutic anticoagulation. Conclusion: Patients with oesophageal cancer undergoing neoadjuvant chemoradiotherapy and surgery are at substantial risk of thromboembolic and bleeding events throughout all stages of treatment. Survival is worse in patients with thromboembolic events during follow-up

Long-term health-related quality of life after McKeown and Ivor Lewis esophagectomy for esophageal carcinoma

Introduction: Both cervical (McKeown) and intrathoracic (Ivor Lewis) anastomosis of transthoracic esophagectomy are surgical procedures that can be performed for distal esophageal or gastro-esophageal junction (GEJ) cancer. The purpose of this study was to investigate the long-term health-related quality of life (HR-QoL) after McKeown and Ivor Lewis esophagectomy in a tertiary referral center. Methods: Disease-free patients >1 year following a McKeown or an Ivor Lewis esophagectomy with a two-field lymphadenectomy for a distal or GEJ carcinoma visiting the outpatient clinic between 2014 and 2018 were asked to complete the EORTC QLQ-C30 and EORTC QLQ-OG25 questionnaires. HR-QoL was investigated in both groups. Results: A total of 89 patients were included after McKeown and 115 after Ivor Lewis esophagectomy. Median follow-up was 2.4 years (IQR 1.7-3.6). Patients after McKeown esophagectomy reported more problems with 'eating with others' compared to patients after Ivor Lewis esophagectomy (mean scores: 49.9 vs. 38.8). This difference was both clinically relevant and significant after correction for multiple testing (β = 11.1, 95% CI 3.105-19.127, P = 0.042). Patients in both groups reported a poorer HR-QoL (≥10 points) than the general population with respect to nausea and vomiting, dyspnea, appetite loss, financial difficulties, problems with eating, reflux, eating with others, choked when swallowing, trouble with coughing, and weight loss. Conclusion: Long-term HR-QoL of disease-free patients following a McKeown or Ivor Lewis esophagectomy for a distal or GEJ carcinoma is largely comparable. Irrespective of the surgical technique, patients' HR-QoL following esophagectomy is compromised. When given the choice, patients should be informed that after a McKeown esophagectomy more problems while eating with others can occur

Improved temperature monitoring and treatment planning for loco-regional hyperthermia treatments of non-muscle invasive bladder cancer (NMIBC)

Introduction— Hyperthermia is a cancer treatment that increases the effectiveness of radiotherapy or chemotherapy by heating the tumor area to 41-43°C. Recently, a multi-center phase III randomized clinical trial comparing adjuvant treatment of NMIBC using Mitomycin C with and without loco-regional hyperthermia has started. This invites careful consideration of the bladder as a treatment site. Optimal treatment and quality control requires reliable thermometry and accurate hyperthermia treatment planning. This study aims to improve the current standard in both areas. Materials & methods— We developed a novel multi-sensor ‘umbrella probe’ with five thermocouple probes to measure the bladder wall temperature, and a central probe measuring in the bladder center. We extended our treatment planning system with a fluid model computing the convective heat flow within the bladder. The umbrella probe was tested using phantom experiments comparing temperature measurements on the interior and exterior of a porcine bladder placed in tissue equivalent gel, and heated to reach a 4°C temperature rise. The experiments were simulated using both the new convective model and the standard treatment planning system. Results— The umbrella probe temperature measurements at the interior bladder wall were comparable to temperatures measured on the bladder exterior but differed 0.5°C from temperatures in the bladder center. The temperature distributions computed by the new convective model and by the current treatment planning system showed good agreement within the phantom’s gel regions; temperature differences between the models exceeded ±1°C inside the fluid and in neighboring tissue regions, i.c. the bladder wall. Conclusions— The umbrella probe reliably measures the clinically relevant bladder wall temperature. The convective model is a marked improvement over the current treatment planning system in the region of interest. Explicit modeling of fluids is particularly important when the bladder or its direct vicinity are part of the hyperthermia treatment target area