Optimization of high–dose-rate intracavitary brachytherapy schedule in the treatment of carcinoma of the cervix

High-Dose-Rate Orthogonal Intracavitary Brachytherapy with 9 Gy/Fraction in Locally Advanced Cervical Cancer: Is it Feasible??

“…Earlier studies on HDR ICBT with 9 Gy per fraction in two fractions [3,[6][7][8] have failed to find any significantly increased toxicity with the regime. Similarly, in the current study, there was no significantly increased toxicity with HDR ICBT using 9 Gy per fraction in two fractions.…”

“…So, in spite of its radiobiologic disadvantages of greater probability of late effects, HDR ICBT gained popularity [7]. The probability of late effects has been lowered by fractionation and adjustment of the total dose in HDR ICBT [6]. To determine the optimum fractionation in HDR ICBT, radiation oncologists have used bioeffect dose models, which convert HDR doses to LDR equivalent doses.…”

“…Patel et al [6][7][8], Sood et al [3] and Souhami et al [14] have described their experiences with [7.5 Gy per fraction HDR ICBT dose and reported their fractionation schedules to be safe and effective in the treatment of cervical cancer. In the current study, it was found that 9 Gy per fraction in two fractions had better efficacy (though not statistically significant) than that of 7 Gy per fraction in three fractions in terms of local tumour control.…”

“…There have been few studies where the authors have demonstrated that HDR ICBT is also quite safe and equally effective if the dose per fraction is higher than 7.5 Gy, as opposed to the ABS [3,6,7]. Even before the ABS recommendations, in 1994, Patel et al [8] demonstrated the efficacy of HDR ICBT with 9 Gy per fraction for two fractions when compared to the then standard of continuous low-dose-rate (LDR) ICBT with 35 Gy.…”

Functional Radiotherapy Targeting using Focused Dose Escalation

“…For example, in the ACT I UKCCCR Anal Cancer Trial (1996), patients were treated with 45 Gy in 20e25 fractions to the pelvis (anus up to the mid-pelvic line to include the inguinal lymph nodes), which was subsequently followed by 15 Gy in six fractions to the perineal field with electrons or photons, or by an iridium-192 implant to 25 Gy at 10 Gy per day [43]. Similar techniques can be cited for cervical cancer [44,45], head and neck cancer [46,47] and prostate cancer [48,49]. In these examples the choice of the volume for the boost was not based on any biological information, but instead it was determined by the area perceived to be at Examples of doseeresponse curves for individuals with relatively resistant tumours (blue) and for individuals with relatively sensitive tumours (orange).…”