Feasibility study of conformal forward planned simultaneous integrated boost technique comparable to IMRT and VMAT in pelvic irradiation for locally advanced cervical cancer

Aim: To check the feasibility of simultaneous integrated boost (SIB) using a forward planned field in field (FIF) conformal technique for the treatment of carcinoma of the cervix IIIB and compare it dosimetrically with other advanced inverse planning techniques.

Methods: In our study 33 patients of carcinoma of the cervix IIIB were planned for SIB using conformal FIF technique and they were compared with retrospectively planned IMRT and VMAT techniques. SIB using conformal FIF was planned by two different methods.

Results: The results of our study indicate that forward planned Conformal SIB techniques are comparable with inverse planned techniques dosimetrically, in terms of conformity Index, Homogeneity Index, Maximum dose, etc. The ability of FIF SIB plans to produce dose contrast in differential dose accumulation was compared and analyzed and the results were encouraging. To treat an advanced/bulky disease like Carcinoma of the Cervix IIIB in centers with large patient load, utilizing advanced techniques such as IMRT and VMAT is both technically and practically difficult. Despite VMAT’s shorter delivery time, the procedures involved are time-consuming.

Conclusion: Hence forward planned SIB techniques may be used to achieve similar dosimetric effects of IMRT and VMAT techniques without much compromise in plan quality and patient throughput for treating bulky carcinoma of the cervix IIIB cases. However, the clinical results need to be carefully compared and evaluated and reported.