Split-field versus extended-field step-and-shoot IMRT techniques in nasopharyngeal cancer: a report of acute and late toxicities

Author(s):  
Wimrak Onchan ◽  
Wannapha Nobnop ◽  
Patrinee Traisathit ◽  
Somvilai Chakrabandhu ◽  
Ekkasit Tharavichitkul ◽  
...  

Abstract Aim: This study aimed to evaluate acute and late toxicities in nasopharyngeal cancer (NPC) patients who were treated between split-field (SF) and extended-field (EF) step-and-shoot intensity-modulated radiotherapy (IMRT) techniques. Materials and methods: Between January 2011 and October 2011, 21 NPC patients with stage I-IVB (7th edition American Joint Committee on Cancer Staging) were randomly assigned to undergo radiotherapy with SF or EF step-and-shoot IMRT technique. Results: At a median follow-up time of 60 months (range 3–77), we reported the comparable acute and late toxicities between the two techniques. One patient (9%) in SF-IMRT arm developed grade 3 acute skin toxicity. Findings: Both SF and EF step-and-shoot IMRT techniques for NPC patients did not produce any statistically significant differences in both acute and late toxicities. Although no difference in toxicity was observed, technical problems due to field matching management were the obstacles in utilisation of SF-IMRT in our routine practice.

2018 ◽  
Vol 18 (02) ◽  
pp. 132-137
Author(s):  
Khaldoon Mahmoud Radaideh

AbstractBackgroundThe purpose of this study was to investigate variations in surface dose, with and without the use of a Klarity® Mask (Orfit Industries America, Wijnegem, Belgium), using intensity-modulated radiotherapy (IMRT) and 3-D conventional radiotherapy (3D-CRT).Materials and methodsThermoluminescent dosimeters (TLDs) together with a phantom were used to examine acute skin toxicity during nasopharyngeal cancer treatment. These plans were sequentially delivered to the perspex phantom. Dosimeters were placed in five fixed regions over the skin. A Klarity mask for immobilization was used for covering the head, neck, and shoulder. The phantom was irradiated with and without a Klarity Mask, using IMRT and 3D-CRT, respectively.ResultsThe Klarity mask increased the skin doses for IMRT and 3D-CRT approximately 18·6% and 8·6%, respectively, from the prescribed maximum skin dose using treatment planning system (TPS). Additionally, the average percentage dose between IMRT and 3D-CRT received on the surface region was 30·9%, 24·9% with and without Klarity mask respectively. The average percentage dose received on surfaces from the total therapeutic dose 70 Gy, without using the mask was 7·7% and 5·7%, for IMRT and 3D-CRT, respectively. The TPS overestimated the skin dose for IMRT planning by 20%, and for 3D-CRT by 16·6%, compared with TLD measurements.ConclusionsThe results of this study revealed that IMRT significantly increases acute skin toxicity, compared with CRT. Although it is recommended to use Klarity mask as a sparing tool of normal tissue, it increases the risk of skin toxicity. In conclusion, skin dose is an important issue of focus during radiotherapy.


2006 ◽  
Vol 102 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Kristina Gerszten ◽  
Kelly Colonello ◽  
Dwight E. Heron ◽  
Ron J. Lalonde ◽  
Issa D. Fitian ◽  
...  

2020 ◽  
Author(s):  
Yuhua Zhao ◽  
Gong Li ◽  
Lei Gao

Abstract Background: This study aimed to evaluate the therapeutic efficacy of extended-field intensity-modulated radiotherapy (EF-IMRT) and dosage boost for positive lymph nodes, prognostic factors, treatment failure, and toxicity for Federation of Gynecology and Obstetrics (FIGO) stage IIICr and IVA cervical cancer patients with positive regional lymph nodes.Methods: We retrospectively evaluated 34 patients with stage IIICr and IVA who had received treatment in our institute between 2013 and 2016. Patients with stage IVA cervical cancer who had been enrolled in the analysis all had positive regional lymph nodes (pelvic or/and para-aortic). All 34 patients were treated with EF-IMRT and simultaneously integrated boost-IMRT (SIB-IMRT) for lymph node metastasis with concurrent chemotherapy and brachytherapy. Positive regional lymph nodes (short-axis diameter ≥5 mm in computed tomography [CT] or magnetic resonance imaging [MRI]) remaining after SIB-IMRT were then treated with sequential boost-IMRT (SeB-IMRT). The prognostic factors for overall survival (OS); disease-free survival (DFS); local control rate (LCR); regional control rate (RCR); distant metastasis-free survival (DMFS), including age, FIGO stage, pretreatment hemoglobin (HB) level, tumor size, para-aortic lymph node (PALN) metastasis, point A equivalent dose in 2-Gy fractions (EQD2 dose), concurrent chemotherapy, and adjuvant chemotherapy cycles, were analyzed.Results: Complete response (CR) was achieved in 31 (91.2%) patients with acceptable adverse effects. Notably, the three-year OS, DFS, LCR, RCR, DMFS for these patients were 73.5%, 70.6%, 88.1%, 87.9%, and 81.6%, respectively. In particular, the three-year OS, DFS, LCR, RCR, and DMFS of patients with positive PALNs was 41.7%, 33.3%, 65.6%, 72.2%, and 60.2%, respectively. The corresponding values in patients without positive PALNs were 90.9%, 90.9%, 100%, 95.5%, and 90.9%, respectively.Conclusions: Our study suggested that the EF-IMRT and nodal dosage boost decreased regional node failure and that patients with stage IIIC1r and IVA cervical cancer without PALN metastasis who received EF-IMRT and SIB-IMRT with or without SeB-IMRT had a significant survival advantage in terms of the DFS and OS.


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