Clarification of FRCR part 1 BOF

First of all, thanks for buying the FRCR part 1 BOF.
I would like to clarify some of the typo and solution to the questions.

Physics

Q26- is it organ movement?

Answer given explaining the organ movement and IGRT is current trend of treatment.Yup, the answer should be D not E typo mistake.

Q28- do you use E/3 or E/4 to cover 90%? For electron energy selection
Rule of thumb X/5 is the Dmax,X/4 is the 90% isodose & X/3 80% isodose, surface dose is X+70% given in the textbook.

But, in daily practice 90% coverage is calculated by E/3.
Coming back to Q28, tumor depth 4cm and the answer selection given by the FRCR is 8,10,12,15,18MeV...there is no answer given that suit x 4 if using textbook formula of E/4.So, FRCR using E/3 =90% isodose line.

Electron energy selection calculated using the tumor depth not diameter of tumor as isodose is a  join points of equal dose.- a planar representation of the dose distribution, meaning dose will be same at the same line/surface as long as the line/surface cover by the beam.

Q44 - CT simulator limitation. This question should be phrased like
CT simulator limitation except

answer is C.....Dont know what I.I stand for but given in the exam.

wedge is make of leads/steal

bolus is make of wax(tissue equivalent material)

Chemo:

Q24-Which has the least risk of neurotoxicity:
A.  Gemcitabine
B.  Oxaliplatin
C.  Paclitaxel
D.  Docetaxel
E.  Vincristine

Answer: shd be A. typo given B as answer in the book but explanation clearly stated.
Common chemo-induced neurotoxicity agents are platinum(oxali), taxane(doce and pacli) and vinca alkaloids(vincristine)

Radbio:

Q 18
In clonogenic assay, 500 cells plated and irritated, 78 colonies growth .Plating
efficacy of 55%, the surviving fraction is:
A.  15%
B.  20%
C.  28%
D.  35%
E.  80%
Answer: C

SF =   Colony no rad/(Seeded cell no rad x PE)

Solution:

SF= Colony growth after irritated(78)/ [seeded no (500) x 55/100%)

    = 78/(500 x .55)
    = 0.283

Ans given in % then 0.283/1 x 100%
   = 28%