Therapy strategies for locally advanced adenoid cystic carcinomas using modern radiation therapy techniques

Abstract

BACKGROUNDThe authors evaluated whether modern photon techniques, such as stereotactic fractionated radiation therapy (FSRT) or intensity‐modulated RT, outweighed the biologic advantages of high‐linear‐energy transfer RT in the treatment of patients with locally advanced adenoid cystic carcinomas (ACC) that infiltrated the skull base or the orbit.METHODSBetween June 1995 and December 2003, 63 patients with ACC were treated with modern RT techniques at the University of Heidelberg. The treatment results achieved with modern photon techniques alone were compared with the results achieved with combined photon RT and a carbon ion boost. Twenty‐nine patients (Group A) were treated with a combination of photon RT and a carbon ion boost. Thirty‐four patients (Group B) received photon RT alone.RESULTSThe median follow‐up was 16 months for Group A and 24 months for Group B. Locoregional control rates at 2 years and 4 years were 77.5% and 77.5% for Group A and 72.2% and 24.6% for Group B, respectively (P = 0.08; log‐rank test). Disease‐free and overall survival rates at 2 years/4 years were 71.5%/53% and 86.6%/75.8% for Group A and 69.2%/23% and 77.9%/77.9% for Group B, respectively. Rates for severe late toxicity were < 5% for both groups.CONCLUSIONSModern RT techniques allowed the safe delivery of high target doses to patients with locally advanced ACC. Late toxicity rates were kept lower compared with the historic neutron therapy data. A combination of modern photon RT and carbon ion RT seemed to be advantageous, with a trend toward higher locoregional control rates compared with modern photon RT alone. Cancer 2005. © 2005 American Cancer Society.

Malignant salivary gland tumours: Can fast neutron therapy results point the way to carbon ion therapy?

“…In another phase I/II trial locally advanced adenoid cystic carcinomas were treated with fractionated stereotactic RT or IMRT to 54 Gy and a carbon ion boost of 18 Gy(RBE). LRC probability was 77.5% at 4 years also with minimal morbidity [23].…”

Review of clinical experience with ion beam radiotherapy

“…Douglas et al [35] published a retrospective analysis of 159 patients with ACC who had been treated with neutrons (total dose: 19.2 Gy), but reported somewhat disappointing LC rates of only 57% at 5 years accompanied by significant late toxicity (14%.CTC ‡3). The results for the combined IMRT- 12 C treatment therefore compare favourably [7] with those for other treatments and include only very mild treatment-related side effects ( ‡3 late toxicity in only one patient). IMRT at 54 Gy [2 Gy/fraction (Fx)] plus a 12 C-boost of 18 GyE (3 GyE/Fx) yielded LC rates of about 78% at 4 years.…”

“…LC was also significantly improved by the application of high-precision techniques, dose-escalation and high linear energy transfer radiation [7,[33][34][35][36]. Both IMRT and FSRT provide better LC than conventional radiotherapy techniques, achieving 3-year progression-free survival (PFS) rates of 38% [37].…”

“…‡3]. Combined treatment with carbon ions and IMRT also improved LC in adenoid cystic carcinoma when compared with IMRT alone, yielding a 77.5% LC at 4 years compared with matched controls of 24.6% LC [7].…”

NTCP reduction for advanced head and neck cancer patients using proton therapy for complete or sequential boost treatment versus photon therapy

“…The use of ion therapy for sequential boost treatment was investigated for malignant salivary gland tumors by several groups showing the feasibility in terms of acceptable toxicity and tumor control [3,4]. A comparison to toxicities in standard radiotherapy was not performed.…”