dose rate at isocenter is 250 cGy/minute. The dose rate at the treatment distance is:
a. 55.5 cGy/min
b. 1125 cGy/min
c. 62.5 cGy/min
d. 12 cGy/min - ✔ ✔ 12 cGy/ min
Inverse square: 250(100/450)^2
All of the following are signs of ovarian cancer except:
a. vaginal bleeding
b. abdominal bloating
c. constipation
d. nausea - ✔ ✔ Vaginal bleeding
An 8 MeV electron beam is used to deliver 300 cGy to the 90% isodose line. The cone size is 15 x 15 and
the SSD is 100 cm SSD. The cone factor is .872 for the specified cone, and the reference dose rate is 1.0
cGy/MU. What MU setting should be used to deliver this treatment?
a. 344 MU
b. 300 MU
c. 382 MU
d. 333 MU - ✔ ✔ 382 MU
,Use the monitor unit formula for SSD technique.
TD/ (cone factor x dose rate x %DD)
An allogenic bone marrow transplant is one in which bone marrow is:
a. removed from the patient, treated with radiation, and inserted back
b. removed from the patient at the time of remission and later reinfused
c. received from a sibling or person immunologically compatible
d. received from an identical twin immunologically compatible - ✔ ✔ received from a sibling or
person immunologically compatible
A dose of 300 cGy was to be delivered to the thoracic spine at 95 cm SSD. An error caused treatment to
be given at an SSD of 92 cm. The actual dose delivered was:
a. 281
b. 291
c. 320
d. 341 - ✔ ✔ 320
Inverse square law: 300(95/92)^2
A field with an approximate size of 21 x 19, having 1 to 2 cm flash over the skull and having the inferior
border at the base of the skull, describes a treatment field for:
a. brain metastases
b. glioblastoma multiforme
c. medulloblastoma
d. ependymoma - ✔ ✔ brain mets
, A glioma spreads primary by way of:
a. local invasion
b. cerebrospinal fluid
c. lymph nodes
d. blood - ✔ ✔ local invasion
A stochastic effect is best defined as one in which:
a. severity is easily predicted
b. severity is dose dependent
c. probability is dose dependent
d. severity has a threshold - ✔ ✔ probability is dose dependent
Bite blocks maybe used in head and neck photon irradiation to:
a. open the patient's mouth for easier breathing
b. protect the oral cavity from secondary scatter
c. protect the oral cavity from primary beam
d. include the submandibular and submental lymph nodes - ✔ ✔
Brachial plexopathy is a possible adverse effect following high dose irradiation to the:
a. humerus
b. abdomen
c. supraclavicular fossa
d. posterior fossa - ✔ ✔ supraclavicular fossa