Authors : Deepak Tuli, Purnima Thakur, Manoj Gupta, Rajeev K Seam, Manish Gupta
DOI : 10.18231/j.ijogr.2019.068
Volume : 6
Issue : 3
Year : 2019
Page No : 302-307
Objective: Knowing that there is a wide variation in pelvic anatomy worldwide, it was an instinctive
query that whether radiotherapy planning in cancer cervix by four field box technique based on GOG
(gynaecologic oncology group) defined field carries adequacy and justification in our region. A prospective
trial was conducted at a Regional Cancer Centre located in Northern India, from August 2014 to July 2015.
CECT (contrast enhanced computed tomography) abdomen and pelvis was done in newly diagnosed 64
patients of cervical cancer with stage IB to IIIB. Using vessels as surrogates for lymph nodes, adequacy of
radiation portals using bony landmarks defined by GOG were assessed.
Materials and Methods: 2D (two dimensional) radiation portals were designed on conventional simulator
”Acuity” as per GOG recommendations. CECT pelvis from L1(first lumbar) to mid femur was done in
the same position along with same immobilization accessories used during conventional simulation. Three
parameters D1, D2 and D3 were defined for adequacy of superior, lateral, and anterior portals respectively.
Results: Increasing the length of AP:PA portal cranially by 4.5 cm will cover the proximal common iliac
nodes adequately. The width of the AP: PA portal needs to be increased by 3.6 cm to cover the distal
external iliac nodes adequately.
Conclusions: Conventional pelvic fields failed to cover all of pelvic lymph nodes in majority of this study
population. Diagnostic CT and MRI are suggested to be referenced to plan pelvic fields precisely when CT
simulation is not available.
Keywords: Cancer cervix, Conventional simulator, Bony landmarks.