Influence of insurance status on the postoperative outcomes of cytoreductive surgery and HIPEC.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is increasingly performed for peritoneal surface malignancies but remains associated with significant morbidity. Scant research is available regarding the impact of insurance status on postoperative outcomes. METHODS: Patients undergoing CRS/HIPEC between 2000 and 2017 at 12 participating sites in the US HIPEC Collaborative were identified. Univariate and multivariate analyses were used to compare the baseline characteristics, operative variables, and postoperative outcomes of patients with government, private, or no insurance. RESULTS: Among 2268 patients, 699 (30.8%) had government insurance, 1453 (64.0%) had private, and 116 (5.1%) were uninsured. Patients with government insurance were older, more likely to be non-white, and comorbid (p < 0.05). Patients with government (OR: 2.25, CI: 1.50-3.36, p < 0.001) and private (OR: 1.69, CI: 1.15-2.49, p = 0.008) insurance had an increased risk of complications on univariate analysis. There was no independent relationship on multivariate analysis. An American Society of Anesthesiologists score of 3 or 4, peritoneal carcinomatosis index score >15, completeness of cytoreduction score >1, and nonhome discharge were factors independently associated with a postoperative complication. CONCLUSION: While there were differences in postoperative outcomes between the three insurance groups on univariate analysis, there was no independent association between insurance status and postoperative complications after CRS/HIPEC.

Malignant hyperthermia in maxillofacial surgery: Literature review supported by case presentation.

OBJECTIVE: Malignant hyperthermia (MH) is characterized by a state of hypermetabolism after exposure to halogenated inhalational anesthetics or succinylcholine. The aims of this study were to carry out an updated review on the subject and report an illustrative case of MH in urgent maxillofacial surgery. MATERIAL AND METHODS: A search of the PubMed/MEDLINE database using the keyword "malignant hyperthermia" was performed including articles published over the last 11 years in English, Spanish or Portuguese. Exclusion criteria were similar presentations but not associated with MH and cases not related to the use of anesthetic drugs as a trigger of the condition. CASE REPORT: A 45-year-old man (75 kg, ASA status IE) with a negative family history for neuromuscular diseases, victim of a car accident with a facial fracture, underwent surgery under balanced general anesthesia and developed signs of MH 4 h after anesthesia induction. In our patient, the causative agent was sevoflurane and the diagnosis of MH was confirmed, subsequently, by muscle biopsy. RESULTS/DISCUSSION: Overall, 44 cases of MH were found. According to the recent literature, MH shows a male predilection (3:1) and the mean age of patients is 32.2 ± 22.2 years. The most frequently cited causative agents were sevoflurane (30.5%), isoflurane (22.2%), and sevoflurane + succinylcholine (13.8%). The most common clinical indicators included hypercarbia (88.8%), hyperthermia (86.1%), and tachycardia (63.8%). Dantrolene was administered in 24 cases. The outcome was favorable in 31 cases (86.1%). The in vitro muscle contracture test (IVCT) was performed in only 15 patients and all of them tested positive. In our patient, the causative agent was sevoflurane and the diagnosis of MH was confirmed by muscle biopsy. CONCLUSION: The mortality from MH is still high and an early clinical diagnosis and specific treatment with dantrolene are necessary for a favorable outcome. A complete understanding will allow better management of patients with MH. At present, the best management is to identify susceptible patients and to avoid triggering agents, combined with vigilant monitoring.

Impact of cumulative complications on 1-year treatment-related healthcare costs in patients with colorectal peritoneal metastases undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

BACKGROUND: The aim of this study was to evaluate the impact of all minor and major complications on treatment-related healthcare costs in patients who undergo cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of colorectal peritoneal metastases (PMs). METHOD: Patients with histologically proven colorectal PMs who underwent CRS + HIPEC from March 2006 to October 2019 in a tertiary referral centre were retrospectively identified from a prospectively maintained database. Patients were divided into six subgroups according to the severity of the complications, which were scored using the comprehensive complication index (CCI) (CCI 0-9.9, CCI 10-19.9, CCI 20-29.9, CCI 30-39.9, CCI 40-49.9, and CCI 50 or higher). Treatment-related healthcare costs up to 1 year after CRS + HIPEC were obtained from the financial department. Differences in costs and survival outcomes were compared using the chi-squared test and Kruskal-Wallis H test. RESULTS: A total of 142 patients were included (CCI 0-9.9, 53 patients; CCI 10-19.9, 0 patients; CCI 20-29.9, 45 patients; CCI 30-39.9, 14 patients; CCI 40-49, 9 patients; and CCI 50 or higher, 21 patients). Median (interquartile range) treatment-related healthcare costs increased significantly and exponentially for the CCI 30-39, CCI 40-49, and CCI 50 or higher groups (€48 993 (€44 262-€84 805); €57 167 (€43 047-€67 591); and €82 219 (€55 487-€145 314) respectively) compared with those for the CCI 0-9.9 and CCI 20-29.9 groups (€33 856 (€24 433-€40 779) and €40 621 (€31 501-€58 761) respectively, P < 0.010). CONCLUSION: Treatment-related healthcare costs increase exponentially as more complications develop among patients who undergo CRS + HIPEC for the treatment of colorectal PMs. Anastomotic leakages after CRS + HIPEC lead to an increase of 295 per cent of treatment-related healthcare costs.

Preoperative cardiopulmonary exercise testing improves risk assessment of morbidity and length of stay following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are the standard treatment for selected patients with peritoneal malignancy. The optimal means of assessing risk prior to these complex operations is not known. This study explored the associations between preoperative cardiopulmonary exercise testing (CPET) variables and postoperative outcomes following elective CRS and HIPEC. This study included patients who underwent routine preoperative CPET prior to elective CRS and HIPEC at Royal Prince Alfred Hospital in Sydney between July 2017 and July 2020. CPET was performed using a cycle ergometer and measured peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). Outcomes included in-hospital morbidity, length of intensive care unit (ICU) stay and hospital stay. The associations between preoperative CPET variables and postoperative morbidity were assessed using univariate and multivariate analyses. A total of 129 patients were included. Mean age was 56 years (standard deviation (SD) 12.5 years), and colorectal cancer was the most common indication for CRS and HIPEC. The overall complication rate was 69%, and two (1.6%) patients died in hospital. Patients who did not develop any postoperative complication had slightly higher preoperative AT and VO2 peak and shorter length of hospital stay. Data in this study support the role of CPET prior to CRS and HIPEC as an adjunct to improve risk assessment.

Cost-effectiveness of Iterative Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for the Treatment of Peritoneal Carcinomatosis.

BACKGROUND: Iterative cytoreduction (iCRS) and hyperthermic intraperitoneal chemotherapy is a treatment for recurrence of peritoneal carcinomatosis. There are considerable upfront costs for this approach for which the cost-effectiveness has not been evaluated. PATIENTS AND METHODS: We used a prospectively maintained database of patients having undergone primary and iterative cytoreduction at St. George Hospital between January 1, 2014, and December 31, 2017, which was linked with financial data. Cost effectiveness and survival outcomes were used to compare primary cytoreduction (pCRS) and iterative cytoreduction (iCRS) in addition to comparison with other treatment modalities. RESULTS: The average cost per patient in Australian dollars was $69,295 ($14,691-$696,002) and the average cost per life-year was $15,842. There was no difference in cost-effectiveness between those who had undergone pCRS and those who had undergone iCRS. The overall survival was 52.5 months (95% confidence interval=49.7-55.2 months) with no difference in survival between pCRS and iCRS groups. The median length of hospital stay was significantly longer for patients in the pCRS treatment group (25.51 days) when compared to the iCRS treatment group (21.15 days, p=0.034). CONCLUSION: iCRS is a cost-effective treatment in the management of recurrent peritoneal carcinomatosis.

Comparative study of heat transfer and thermal damage assessment models for hyperthermia treatment.

Appropriate heating of the tumor can ablate tumor cells with minimal damage to healthy tissue and low side effects to the patient. Therefore, it is important to estimate power dissipation requirement and predict thermal damage in tumor before hyperthermia treatment. This work applied a mathematical model on heat transfer in two-layered spherical tissue to predict the temperature profile within hyperthermia domain. The present bioheat transfer problem was analyzed based on the Pennes equation, the thermal wave and dual-phase lag modes in order to explore the effect of analysis mode on the power dissipation requirement. The Arrenius equation, the modified thermal damage model with regeneration term, and the equivalent thermal dose equation were used to evaluate the thermal damage and discuss their effects on thermal damage prediction. The computation results show that the model of bioheat transfer and the non-Fourier effect significantly affects the power dissipation requirement. The damage parameter value predicted by the modified thermal damage model with regeneration term seems to have a limit value of Ω = 1. The results imply that the regeneration of biological tissue can prevent the tissue from thermal damage, the equivalent thermal dose equation is more related to heating time, and the Arrenius equation is more related to heating temperature.

Large-Volume Hyperthermia for Safe and Cost-Effective Targeted Drug Delivery Using a Clinical Ultrasound-Guided Focused Ultrasound Device.

Lyso-thermosensitive liposomes (LTSLs) are specifically designed to release chemotherapy agents under conditions of mild hyperthermia. Preclinical studies have indicated that magnetic resonance (MR)-guided focused ultrasound (FUS) systems can generate well-controlled volumetric hyperthermia using real-time thermometry. However, high-throughput clinical translation of these approaches for drug delivery is challenging, not least because of the significant cost overhead of MR guidance and the much larger volumes that need to be heated clinically. Using an ultrasound-guided extracorporeal clinical FUS device (Chongqing HAIFU, JC200) with thermistors in a non-perfused ex vivo bovine liver tissue model with ribs, we present an optimised strategy for rapidly inducing (5-15 min) and sustaining (>30 min) mild hyperthermia (ΔT <+4°C) in large tissue volumes (≤92 cm3). We describe successful clinical translation in a first-in-human clinical trial of targeted drug delivery of LTSLs (TARDOX: a phase I study to investigate drug release from thermosensitive liposomes in liver tumours), in which targeted tumour hyperthermia resulted in localised chemo-ablation. The heating strategy is potentially applicable to other indications and ultrasound-guided FUS devices.

Development and Assessment of Nano-Technologies for Cancer Treatment: Cytotoxicity and Hyperthermia Laboratory Studies.

Cancer treatment by magnetic hyperthermia offers numerous advantages, but for practical applications many variables still need to be adjusted before developing a controlled and reproducible cancer treatment that is bio-compatible (non-damaging) to healthy cells. In this work, Fe3O4 and CoFe2O4 were synthesized and systematically studied for the development of efficient therapeutic agents for applications in hyperthermia. The biocompatibility of the materials was further evaluated using HepG2 cells as biological model. Colorimetric and microscopic techniques were used to evaluate the interaction of magnetic nano-materials (MNMs) and HepG2 cells. Finally, the behavior of MNMs was evaluated under the influence of an alternating magnetic field (AMF), observing a more efficient temperature increment for CoFe2O4, a desirable behavior for biomedical applications since lower doses and shorter expositions to alternating magnetic field might be required.

Efficient and Reliable Assessment of the Maximum Local Tissue Temperature Increase at the Electrodes of Medical Implants under MRI Exposure.

Standard risk evaluations posed by medical implants during magnetic resonance imaging (MRI) includes (i) the assessment of the total local electromagnetic (EM) power (P) absorbed in the vicinity of the electrodes and (ii) the translation of P into a local in vivo tissue temperature increase ∆T (P2∆T) in animal experiments or simulations. We investigated the implant/tissue modeling requirements and associated uncertainties by applying full-wave EM and linear bioheat solvers to different implant models, incident field conditions, electrode configurations, and tissue models. Results show that the magnitude of the power is predominately determined by the lead, while the power distribution, and the P2∆T conversion, is determined by the electrode and surrounding tissues. P2∆T is strongly dependent on the size of the electrode, tissue type in contact with the electrode, and tissue inhomogeneity (factor of >2 each) but less on the modeling of the lead (<±10%) and incident field distribution along the lead (<±20%). This was confirmed by means of full-wave simulations performed with detailed high-resolution anatomical phantoms exposed to two commonly used MRI clinical scenarios (64 and 128 MHz), resulting in differences of less than 6%. For the determination of P2∆T, only the electrode and surrounding tissues must be modeled in great detail, whereas the lead can be modeled as a computationally efficient simplified structure exposed to a uniform field. The separate assessments of lead and electrode reduce the overall computational effort by several orders of magnitude. The errors introduced by this simplification can be considered by uncertainty terms. Bioelectromagnetics. 2019;40:422-433. © 2019 Bioelectromagnetics Society.

Major influence of postoperative complications on costs of cytoreductive surgery and HIPEC in patients with colorectal peritoneal metastases.

Complications after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) result in impaired short- and long-term outcomes. However, financial consequences of complications after CRS and HIPEC in a European health care setting are unknown. This study aims to assess the consequences of complications on hospital costs after CRS and HIPEC.In this prospective observational cohort study, patients with colorectal peritoneal metastases treated with CRS and HIPEC were included. Financial information was collected according to the Dutch manual for costs analyses. Costs were compared between patients without complications (NC), minor complications (MC), or severe complications (SC), according to the Clavien-Dindo classification.One hundred and sixty-one patients were included, of whom 42% experienced NC, 27% MC and 31% SC. Mean hospital costs were &OV0556;9.406 ±â€Š2.235 in NC patients, &OV0556;12.471 ±â€Š3.893 in MC patients, and &OV0556;29.409 ±â€Š22.340 in SC patients. The 31% of patients with severe complications accounted for 56% of all hospital costs. Hospital admission costs in SC patients were 320% higher compared to NC patients. Costs of complications were estimated to be 43% of all admission costs.Severe postoperative complications have major influence on costs after CRS and HIPEC and result in a threefold increase of hospital costs in affected patients. This finding stresses the need for adequate risk assessment of developing severe complications after CRS and HIPEC.

Preoperative nutritional risk assessment in patients undergoing cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for colorectal carcinomatosis.

BACKGROUND: Malnutrition is associated with increased postoperative morbidity in colorectal surgery. This study aimed to determine if preoperative nutritional markers could predict postoperative outcomes for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for peritoneal metastasis (PM) of colorectal origin. METHODS: All patients who underwent a complete CRS-HIPEC for colorectal PM between January 2009 and December 2014 were evaluated. Preoperative clinical and biological nutritional factors, including Body Mass Index (BMI), preoperative albumin and prealbumin levels were analysed. Preoperative computed tomography was used to measure the cross-sectional surface of the visceral and subcutaneous adipose tissue, at the third lumbar vertebrae, to assess the abdominal fat composition. Skeletal muscle mass was measured to assess for sarcopenia. RESULTS: Among 214 patients, 14 (6.5%) had a BMI ≥ 35 kg/m2, 90 (42%) were sarcopenic, 19 (9%) presented albumin <35 g/L and 2 (1%) had pre-albumin <20 mg/dL. Median values for visceral and subcutaneous fat surfaces were 99.2 cm2 and 198 cm2, respectively. Hypoalbuminemia was associated with worse overall survival (23 vs. 59 months, p = 0.015). The other nutritional factors did not impact overall or progression free survival after CRS-HIPEC for colorectal PM. In multivariate analysis, major post-operative complication and hypoalbuminemia were independently associated with decreased overall survival. CONCLUSIONS: Hypoalbuminemia appears as a strong predictive factor for decreased overall survival in patients presenting PM of colorectal origin undergoing CRS-HIPEC.

Is hyperthermic intraperitoneal chemotherapy (HIPEC) safe for healthcare workers?

BACKGROUND: During hyperthermic intraperitoneal chemotherapy (HIPEC), caregivers are exposed by different routes to cytotoxic drugs. This review proposes an overview of the safety of HIPEC by assessing existing data on protection procedures, biological and non-biological samples. Based on these data, relevant good practices, eventual irrelevant overprotection procedures and missing data to implement adapted protections are highlighted. MATERIALS AND METHODS: Data were extracted from a systematic review of literature from 1980 till 2016: number and type of surgical procedure, healthcare professionals present, protective equipment, samples, pre-analytical method and analytical method. RESULTS AND DISCUSSION: Only 55 HIPEC procedures have been evaluated. The majority of antineoplastic drugs used have all required characteristics to penetrate the organism and are recognized as very dangerous. Moreover, a great heterogeneity in protective equipment used, either individual or collective is observed. Environmental contamination occurs during HIPEC, especially for all surfaces in the operating room. Compounds penetration into caregivers lungs cannot be excluded. Priority remains to prove professionals contamination by focusing on biological samples. Biological material is rarely sampled or samples are not necessarily adapted. CONCLUSION: Repeated blood tests should be preferred using appropriate sampling schedules and validated sensitive analytical methods. Furthermore, there is a great need of new biological indicators to monitor caregivers exposure. During hyperthermic intraperitoneal chemotherapy (HIPEC), healthcare workers are exposed by different routes to cytotoxic drugs. There are currently few available occupational exposure data and environmental monitoring and biomonitoring must be improved in order to ensure optimal protection against antineoplastic drugs.

Cost-effectiveness analysis of thermotherapy versus pentavalent antimonials for the treatment of cutaneous leishmaniasis.

OBJECTIVE: The treatment of cutaneous leishmaniasis is toxic, has contraindications, and a high cost. The objective of this study was to estimate the cost-effectiveness of thermotherapy versus pentavalent antimonials for the treatment of cutaneous leishmaniasis. METHODS: Effectiveness was the proportion of healing and safety with the adverse effects; these parameters were estimated from a controlled clinical trial and a meta-analysis. A standard costing was conducted. Average and incremental cost-effectiveness ratios were estimated. The uncertainty regarding effectiveness, safety, and costs was determined through sensitivity analyses. RESULTS: The total costs were $66,807 with Glucantime and $14,079 with thermotherapy. The therapeutic effectiveness rates were 64.2% for thermotherapy and 85.1% for Glucantime. The average cost-effectiveness ratios ranged between $721 and $1275 for Glucantime and between $187 and $390 for thermotherapy. Based on the meta-analysis, thermotherapy may be a dominant strategy. CONCLUSION: The excellent cost-effectiveness ratio of thermotherapy shows the relevance of its inclusion in guidelines for the treatment.

Enterocutaneous fistula in patients with peritoneal malignancy following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: Incidence, management and outcomes.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an effective treatment for peritoneal carcinomatosis (PC) from multiple origins, however is associated with increased complications compared to conventional gastrointestinal surgery. The aetiology of enterocutaneous fistulas (ECF) in most cases is a result of various contributing factors and therefore remains a major clinical problem, occurring in 4-34% of patients post-CRS. The aim of this study was to analyze the incidence and outcome of ECF following CRS/HIPEC. METHOD: From April 1999 to September 2015, 53 patients of 918 CRS/HIPEC procedures developed an ECF. Patient, operative and postoperative data were retrospectively analyzed to determine aetiology, classification outcome and possible contributing factors were reviewed on univariate and multivariate analysis. RESULTS: We report a 5.8% ECF rate, diagnosed at a median of 13 days. The mortality rate was 5.7% and other morbidity was significantly increased (p = 0.0001). Twenty-five (47.2%), 8 (15.1%) and 20 patients (37.7%) had low, moderate and high output ECF respectively. Patients that had a CC2 cytoreduction, abdominal VAC or smoked had a higher risk of fistula (p = 0.004, p < 0.0001, p = 0.008). Spontaneous closure was achieved in 49.2% with conservative treatment (median 29 days) and 33.9% underwent surgical intervention. Preoperative serum albumin <35 g/L (p = 0.04), PCI>17 (p = 0.025) and operation >8.6 h s (p = 0.001) were independent risk factors on multivariate analysis. Overall and 5-year survival was significantly reduced (p < 0.0001,p = 0.016). CONCLUSION: CRS/HIPEC remains an effective treatment modality for PC in selected patients with a comparable ECF incidence to reported elective gastrointestinal surgery rates. This study identifies multiple risk factors that should be considered in patients undergoing CRS/HIPEC.

"Assessment of RIFLE and AKIN criteria to define acute renal dysfunction for HIPEC procedures for ovarian and non ovarian peritoneal malignances".

BACKGROUND: The acute renal dysfunction (ARD) is a common complication in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). Our aim is evaluate the ARD post-HIPEC procedures using the RIFLE and AKIN criteria. Evaluate the risk factors and analyze ARD's impact on postoperative course. METHODS: From 2011 to 2014, in a retrospective way using a prospective database were operated by HIPEC procedure. The ARD was analyzed by RIFLE and AKIN criteria. The perioperative features were analyzed and a multivariate analysis was performed to define the risk factors to develop the ARD. RESULTS: 141 patients were treated and analyzed. The ARD was detected in 30.5% (Injury 18.4% and Failure 12.1%) when RIFLE criteria were applied. The multivariate analysis detected that decrease of pH during HIPEC [OR = 29.39 (5.09-169.76)], PCI [OR = 1.07 (1.01-1.15)] and ureteral catheters [OR = 12.71 (1.44-111.85)] were associated to the development of acute renal injury (ARI) post-HIPEC. Decrease of Na during HIPEC [OR = 1.15 (1.01-1.30)], intraoperative inotrope use [OR = 3.83 (1.12-13.09)] and PCI [OR = 1.06 (1.0-1.14)] were associated to acute renal failure (ARF) post-HIPEC. The ARD was related to a higher length of stay hospital (17.2 ± 11 vs. 13.8 ± 8 days) (p = 0.05) but no impact in early survival was observed in ARD group. CONCLUSIONS: The widespread use of RIFLE criteria for ARD would have major benefits in terms of accurately diagnosing patients undergone HIPEC procedures. The ARD has a detrimental impact in length of stay hospital. The knowledge of risk factors helps us to prevent the ARD post-HIPEC by means of an aggressive and multidisciplinary perioperative management.

Assessment of thermal treatment via irrigation of external ear to reduce cisplatin-induced hearing loss.

Systemic and local changes in body temperature can have a profound effect on traumatic injuries including those to the inner ear. Therefore, we investigated the effects of acutely increasing or decreasing the temperature of the external ear canal on cisplatin-induced hearing loss. The external auditory canals of male guinea pigs were acutely irrigated with warm (44 °C), euthermic (37 °C), or cool (30 °C) water and subsequently injected with cisplatin (12 mg/kg, i.p.). Hearing was assessed by the auditory brainstem response and cochleograms were prepared to determine loss of hair cells. Ear canal irrigation with warm water potentiated cisplatin-induced hearing loss and outer hair cell loss whereas cool ear canal irrigation showed significant protection from cisplatin-induced hearing loss and outer hair cell loss. These results suggest that non-invasive cool water ear canal irrigation may be highly effective clinical procedure for protecting against cisplatin-induced hearing loss.

Novel low-cost thermotherapy for cutaneous leishmaniasis in Peru.

Thermotherapy is an accepted alternative therapy for new-world cutaneous leishmaniasis, but current heat-delivery modalities are too costly to be made widely available to endemic populations. We adapted a low-cost heat pack named the HECT-CL device that delivers safe, reliable, and renewable conduction heat. 25 patients with cutaneous leishmaniasis completed treatment with the device at an initial temperature of 52°C ± 2°C for 3 minutes to each lesion, repeated daily for 7 days, and were followed up for 6 months by direct observation. The overall definitive clinical cure rate was 60%. Concurrently, 13 patients meeting minimally significant exclusion criteria received identical compassionate use treatment with a cumulative definitive cure rate of 68.4%, 75% for those who had experienced CL relapse after prior antimonial treatment. Therapy was well tolerated. Reversible second-degree burns occurred in two patients and no bacterial super-infections were observed. HECT-CL is a promising treatment and deserves further study to verify its safety and efficacy as adjuvant and mono- therapy.

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.

Complaint-adaptive power density optimization as a tool for HTP-guided steering in deep hyperthermia treatment of pelvic tumors.

For an efficient clinical use of HTP (hyperthermia treatment planning), optimization methods are needed. In this study, a complaint-adaptive PD (power density) optimization as a tool for HTP-guided steering in deep hyperthermia of pelvic tumors is developed and tested. PD distribution in patients is predicted using FE-models. Two goal functions, Opt1 and Opt2, are applied to optimize PD distributions. Optimization consists of three steps: initial optimization, adaptive optimization after a first complaint and increasing the weight of a region after recurring complaints. Opt1 initially considers only target PD whereas Opt2 also takes into account hot spots. After patient complaints though, both limit PD in a region. Opt1 and Opt2 are evaluated in a phantom test, using patient models and during hyperthermia treatment. The phantom test and a sensitivity study in ten patient models, show that HTP-guided steering is most effective in peripheral complaint regions. Clinical evaluation in two groups of five patients shows that time between complaints is longer using Opt2 (p = 0.007). However, this does not lead to significantly different temperatures (T50s of 40.3 (Opt1) versus 40.1 degrees C (Opt2) (p = 0.898)). HTP-guided steering is feasible in terms of PD reduction in complaint regions and in time consumption. Opt2 is preferable in future use, because of better complaint reduction and control.