The authors declare that they have no competing interests.
RY contributed to the design of the study, acquisition of data, interpretation of data, and drafted the manuscript. YM contributed to the analysis and interpretation of data, and helped draft the manuscript. HW contributed to the acquisition and interpretation of data, and assisted with drafting the manuscript. DG and BW contributed to the interpretation of data. JK contributed to the conception and design of this study and interpretation of data. CD contributed to the conception and design of this study, interpretation of data and assisted with drafting the manuscript. All authors read and approved the final manuscript.
Intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) have been adopted for radiotherapy treatment of anal canal carcinoma (ACC) due to better conformality, dose homogeneity and normal-tissue sparing compared to 3D-CRT. To date, only one published study compares dosimetric parameters of IMRT vs HT in ACC, but there are no published data comparing toxicities. Our objectives were to compare dosimetry and toxicities between these modalities.
This is a retrospective study of 35 ACC patients treated with radical chemoradiotherapy at two tertiary cancer institutions from 2008–2010. The use of IMRT vs HT was primarily based on center availability. The majority of patients received fluorouracil (5-FU) and 1–2 cycles of mitomycin C (MMC); 2 received 5-FU and cisplatin. Primary tumor and elective nodes were prescribed to ≥54Gy and ≥45Gy, respectively. Patients were grouped into two cohorts: IMRT vs HT. The primary endpoint was a dosimetric comparison between the cohorts; the secondary endpoint was comparison of toxicities.
18 patients were treated with IMRT and 17 with HT. Most IMRT patients received 5-FU and 1 MMC cycle, while most HT patients received 2 MMC cycles (p < 0.01), based on center policy. HT achieved more homogenous coverage of the primary tumor (HT homogeneity and uniformity index 0.14 and 1.02 vs 0.29 and 1.06 for IMRT, p = 0.01 and p < 0.01). Elective nodal coverage did not differ. IMRT achieved better bladder, femoral head and peritoneal space sparing (V30 and V40, p ≤ 0.01), and lower mean skin dose (p < 0.01). HT delivered lower bone marrow (V10, p < 0.01) and external genitalia dose (V20 and V30, p < 0.01). Grade 2+ hematological and non-hematological toxicities were similar. Febrile neutropenia and unscheduled treatment breaks did not differ (both p = 0.13), nor did 3-year overall and disease-free survival (p = 0.13, p = 0.68).
Chemoradiotherapy treatment of ACC using IMRT vs HT results in differences in dose homogenity and normal-tissue sparing, but no significant differences in toxicities.
Bartelink H, Roelofsen F, Eschwege F, Rougier P, Bosset JF, Gonzalez DG, et al. Concomitant radiotherapy and chemotherapy is superior to radiotherapy alone in the treatment of locally advanced anal cancer: results of a phase III randomized trial of European Organization for Research and Treatment of Cancer Radiotherapy and Gastrointestinal Cooperative Groups. J Clin Oncol. 1997;15:2040–9. PubMed
Flam M, John M, Pajak TF, Petrelli N, Myerson R, Doggett S, et al. Role of mitomycin in combination with fluorouracil and radiotherapy, and of salvage chemoradiation in the definitive nonsurgical treatment of epidermoid carcinoma of the anal canal: results of a phase III randomized intergroup study. J Clin Oncol. 1996;14:2527–39. PubMed
Gunderson LL, Winter KA, Ajani JA, Pedersen JE, Moughan J, Benson AB, et al. Long-term update of U.S. GI Intergroup RTOG 98–11 phase III trial for anal carcinoma: survival, relapse and colostomy failure with concurrent chemoradiation involving fluorouracil/mitomycin versus fluroruracil/cisplatin. J Clin Oncol. 2012;30:4344–51. CrossRefPubMedCentralPubMed
James RD, Glynne-Jones R, Meadows HM, Cunningham D, Myint AS, Saunders MP, et al. Mitomycin or cisplatin chemoradiation with or without maintenance chemotherapy for treatment of squamous-cell carcinoma of the anus (ACT II): a randomized, phase 3, open-label, 2x2 factorial trial. Lancet Oncol. 2013;14:516–24. CrossRefPubMed
Kachnic LA, Winter K, Myerson RJ, Goodyear MD, Willins J, Esthappan J, et al. RTOG 0529: a phase 2 evaluation of dose-painted intensity-modulated radiation therapy in combination with 5-fluroruracil and mitomycin-c for the reduction of acute morbidity in carcinoma of the anal canal. Int J Radiat Oncol Biol Phys. 2013;86:27–33. CrossRefPubMedCentralPubMed
Lian J, Mackenzie M, Joseph K, Pervez N, Dundas G, Urtasun R, et al. Assessment if extended-field radiotherapy for stage IIIc endometrial cancer using three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy. Int J Radiat Oncol Biol Phys. 2008;70:935–43. CrossRefPubMed
Skórska M, Piotrowski T, Kaźmierska J, Adamska K. A dosimetric comparison of IMRT versus helical tomotherapy for brain tumors. Physica Medica. 2014;29:221–3.
Cox JD, Stetz J, Pajak TF. Toxicity criteria for the radiation therapy oncology group (RTOG) and the European Organization for research and treatment of cancer (EORTC). Int J Radiat Oncol Biol Phys. 1995;31:1341-46.
Tan YI, Metwaly M, Glegg M, Baggarley S, Elliott A. Evaluation of six TPS algorithms in computing entrance and exit doses. J Appl Clin Med Phy. 2014;15:229–40.
Capelle L, Warkentin H, Mackenzie M, Joseph K, Gabos Z, Pervez N, et al. Skin-sparing Helical Tomotherapy vs 3D-conformal radiotherapy for adjuvant breast radiotherapy: in vivo skin dosimetry study. Int J Radiat Oncol Biol Phys. 2012;83:583–90. CrossRef
Yeung R, McConnell Y, Roxin G, Banerjee R, Urgoiti GB, MacLean AR, et al. One vs two cycles of mitomycin C in chemoradiotherapy for anal cancer: analysis of outcomes and toxicity. Curr Oncol. 2014;21:449–56. CrossRef
- Intensity-Modulated Radiotherapy (IMRT) vs Helical Tomotherapy (HT) in Concurrent Chemoradiotherapy (CRT) for Patients with Anal Canal Carcinoma (ACC): an analysis of dose distribution and toxicities
Corinne M Doll
- BioMed Central
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