Higher radiation dose with a shorter treatment duration improves outcome for locally advanced carcinoma of anal canal

Abstract

AIM:To assess whether radiation dose and duration of treatment influence local control and survival of patients with locally advanced anal cancer treated with definitive chemoradiation. METHODS:Twenty-eight consecutive patients who were treated with definitive radiation therapy for bulky anal cancers (> 5 cm in size) were reviewed. Nineteen patients had T3 lesions, 8 patients had T4 lesions, and 15 patients had lymph node involvement. The median tumor size was 7.5 cm. All but one patient received concurrent chemoradiation. The median radiation dose was 54 Gy. The median duration of treatment was 58 d. RESULTS:With a median follow-up of 2.5 years in all patients and 7.8 years in living patients, the 2-year local recurrence-free probability was 57% and overall survival rate was 67%. Neither radiation dose nor duration of treatment alone was predictive of either time to local failure or overall survival. However, longer treatment breaks can potentially mask an advantage over higher radiation doses. Therefore, we examined those patients who received ≥ 54 Gy within 60 d, comparing them to the rest of the patients. Of patients who received ≥ 54 Gy within 60 d, local progression-free probability was 89% versus 42% for the rest of the group (P = 0.01). CONCLUSION:Local failure is a significant problem in locally advanced carcinomas of the anal canal. Higher radiation doses with limited treatment breaks may offer an increase in local control and survival.

Intensity-modulated radiotherapy for squamous cell carcinoma of the anal canal: Efficacy of a low daily dose to clinically negative regions

“…Multiple IMRT plans could be used to allow no change in fractional dose during the treatment period, but this requires additional planning and quality assurance and also extends the treatment time. Increased treatment times may be associated with poor disease control (7)(8)(9)(10)(11)(12)(13). Use of IMRT to deliver an SIB has the advantage of being able to deliver the radiation in a shorter time.…”

Efficacy and safety of helical tomotherapy with daily image guidance in anal canal cancer patients

“…Randomized controlled trials (RCT) published in the 1990s definitely assessed the role of concomitant CT, in particular for locally advanced tumors [2]. Optimal dose levels and schedules of EBRT are still under investigation [1] but doses ranging between 45 and 59 Gy showed to be curative, with higher doses needed in poor responders patients [1][2][3][4]. However, international recommendations support the delivery of a boost after the first course of EBRT with or without computed tomography (CT) delivered to the pelvic nodes and to the primary tumor [1], which could be delivered using EBRT or brachytherapy (BRT) [1, 2,5,6].…”

Is neoadjuvant chemotherapy prior to radio‐chemotherapy beneficial in T4 anal carcinoma?

“…Increased toxicities have been observed in patients treated with higher radiation doses [47,49]. One way to decrease toxicity is to treat patients using intensity-modulated radiation therapy (IMRT) in order to avoid treatment breaks while excluding the potential risk of underdosage [24,[50][51][52][53][54][55][56].…”