The cooling effect of blood flow during hyperthermia treatment.

The amount and duration of the applied heat in hyperthermia treatment are critical for cancer survivors. The challenge is to use a mechanism dealing with the tumor cells only while keeping healthy tissues unharmed. The aim of this paper is to predict the blood temperature distribution in main dimensions during hyperthermia process by deriving a new analytical solution of unsteady flow that adequately covers the cooling factor. We adopted a separation of variable method to solve the bio-heat transfer problem of unsteady blood flow. The solution is similar to Pennes' equation, except that it is for blood rather than tissue. We also performed computational simulations with varied flow conditions and thermal energy transports. The blood cooling effects were calculated with vessel's diameter, tumor's zone length, pulsating period and flow velocity. The cooling rate rises by around 133% if the tumor zone's length is extended four times the diameter of 0.5 (mm), but it is seemingly fixed with this distance if the diameter is equal or larger than 4 (mm). Likewise, the temporal variations of temperature disappear if the blood vessel has a diameter of 4 (mm) or more. Pre-heating or post-cooling techniques perform effectively given the theoretical solution; under particular conditions, the reduction percentages of the cooling effect are between 130% and 200%, respectively.

Implant Utilization and Time to Prosthetic Rehabilitation in Conventional and Advanced Fibular Free Flap Reconstruction of the Maxilla and Mandible.

PURPOSE: Precisely designed jaw reconstruction rehabilitation (JRR) is important to the integrity of the jaw structure and oral functions. Advanced three-dimensional (3D) digital surgical design and simulation (SDS) techniques have the potential to reduce time to reconstructive and dental treatment completion, thereby promoting early functional oral rehabilitation. This study investigated the use of SDS in JRR procedures. MATERIALS AND METHODS: A retrospective chart review was conducted on adult head and neck tumor (HNT) participants who completed JRR treatment with a fibular free flap (FFF) reconstruction. Two treatment approaches, advanced 3D SDS technique (with-SDS) and conventional, nondigitally planned technique (without-SDS), included the use of osseointegrated implants. Data were collected from adult patients treated between January 2000 and March 2014 at the Institute for Reconstructive Sciences in Medicine (iRSM). Participants were excluded if they underwent a bone-containing augmentation to the FFF reconstruction. The without-SDS group underwent a conventional, nonguided FFF reconstruction followed by nonguided implant placement. The with-SDS group underwent a guided FFF reconstruction with guided implant placement during the reconstructive surgery. The outcome measures included implant utilization (ratio of implants placed to connected) and time to prosthetic connection after FFF reconstruction. Mann-Whitney U test was used to analyze the data. RESULTS: The digital SDS technique (with-SDS) group completed prosthetic treatment with a significantly higher utilization of implants as well as a significantly shorter time to prosthetic delivery. CONCLUSION: SDS allows an interdisciplinary treatment team to work together to create a virtual plan that leads to greater efficiency in patient treatment time and utilization of dental implants.