Cancer Treatment Options: Treating Xerostomia Following Radiation

Describe ONE conventional cancer treatment.

State why radiotherapy is an effective cancer treatment. The radiation can be localised to a small area without producing much other damage.1The radiation can find and destroy any diseased cells in the body.2Radiotherapy never has any side effects.

Brain tumors are often treated with radiation consisting of high energy photons, like gamma rays, that kill cancer cells through apoptosis, autophagy, DNA damage, etc.  Local drug delivery provides a high concentration of drug in the tumor while decreasing systemic toxicity.Researchers study a new drug that emits gamma rays at 50 × 1018 Hz and is injected into tumors using a vascular catheter and x-ray imaging guidance.  The x-rays have a lower frequency, 100 × 1015 Hz, compared to gamma rays.  The catheter also collects tumor samples for optical analysis using lenses, as shown in Figure 1.Figure 1  A tissue sample placed 2.5 cm from the center of a convex lens forms an image 10 cm from the lensAn x-ray tube propels high energy electrons at a tungsten target to produce x-rays but also heats the target.  To avoid overheating, tube current I is applied only to collect one x-ray image, followed by a cooling period (Figure 2).  The tungsten target is 1000 °C and 2 cm long after cooling, but it heats to 2000 °C and increases in length by 0.1 mm when generating x-rays.Figure 2  X-ray tube current over timeThe drug is injected into a blood vessel feeding the tumor with the injection syringe and catheter at the same level to eliminate gravitational effects.  In one experiment, two drug doses were compared and the higher drug dose had a greater therapeutic response.  In another experiment, the drug injection velocity was varied and the lowest injection velocity had the greatest therapeutic response. Question 41If the density of the drug is known, what additional information is required to calculate the velocity of the drug as it enters the blood vessel?  (Note: Assume ideal fluid flow.)A.Pressure in syringe, pressure in blood vessel, and mass of drugB.Pressure in syringe, velocity in syringe, and pressure in blood vesselC.Pressure in syringe, velocity in syringe, and volume of drugD.Velocity in syringe, mass of drug, and volume of drug

Brain tumors are often treated with radiation consisting of high energy photons, like gamma rays, that kill cancer cells through apoptosis, autophagy, DNA damage, etc.  Local drug delivery provides a high concentration of drug in the tumor while decreasing systemic toxicity.Researchers study a new drug that emits gamma rays at 50 × 1018 Hz and is injected into tumors using a vascular catheter and x-ray imaging guidance.  The x-rays have a lower frequency, 100 × 1015 Hz, compared to gamma rays.  The catheter also collects tumor samples for optical analysis using lenses, as shown in Figure 1.Figure 1  A tissue sample placed 2.5 cm from the center of a convex lens forms an image 10 cm from the lensAn x-ray tube propels high energy electrons at a tungsten target to produce x-rays but also heats the target.  To avoid overheating, tube current I is applied only to collect one x-ray image, followed by a cooling period (Figure 2).  The tungsten target is 1000 °C and 2 cm long after cooling, but it heats to 2000 °C and increases in length by 0.1 mm when generating x-rays.Figure 2  X-ray tube current over timeThe drug is injected into a blood vessel feeding the tumor with the injection syringe and catheter at the same level to eliminate gravitational effects.  In one experiment, two drug doses were compared and the higher drug dose had a greater therapeutic response.  In another experiment, the drug injection velocity was varied and the lowest injection velocity had the greatest therapeutic response. Question 42Which of the following statements best explains why the higher dose of gamma-emitting drug has a greater therapeutic response?A.The intensity of the gamma rays is greater.B.The frequency of the gamma rays is greater.C.The velocity of the gamma rays is faster.D.The energy of the gamma rays is greater.Submit

Brain tumors are often treated with radiation consisting of high energy photons, like gamma rays, that kill cancer cells through apoptosis, autophagy, DNA damage, etc.  Local drug delivery provides a high concentration of drug in the tumor while decreasing systemic toxicity.Researchers study a new drug that emits gamma rays at 50 × 1018 Hz and is injected into tumors using a vascular catheter and x-ray imaging guidance.  The x-rays have a lower frequency, 100 × 1015 Hz, compared to gamma rays.  The catheter also collects tumor samples for optical analysis using lenses, as shown in Figure 1.Figure 1  A tissue sample placed 2.5 cm from the center of a convex lens forms an image 10 cm from the lensAn x-ray tube propels high energy electrons at a tungsten target to produce x-rays but also heats the target.  To avoid overheating, tube current I is applied only to collect one x-ray image, followed by a cooling period (Figure 2).  The tungsten target is 1000 °C and 2 cm long after cooling, but it heats to 2000 °C and increases in length by 0.1 mm when generating x-rays.Figure 2  X-ray tube current over timeThe drug is injected into a blood vessel feeding the tumor with the injection syringe and catheter at the same level to eliminate gravitational effects.  In one experiment, two drug doses were compared and the higher drug dose had a greater therapeutic response.  In another experiment, the drug injection velocity was varied and the lowest injection velocity had the greatest therapeutic response. Question 44The advantage of using gamma rays for tumor therapy over x-rays is that gamma rays:A.are not electromagnetic radiation.B.are photons.C.have higher energy.D.have a longer wavelength.