ABSTRACT
Purpose@#Intensity-modulated radiotherapy (IMRT) provides higher dose to target volumes and limits the dose to normal tissues. IMRT may be applied using either simultaneous integrated boost (SIB-IMRT) or sequential boost (SEQ-IMRT) technique. The objectives of this study were to compare acute toxicity and objective response rates between SIB-IMRT and SEQ-IMRT in patients with locally advanced head and neck cancer. @*Materials and Methods@#Total 110 patients with locally advanced carcinoma of oropharynx, hypopharynx, and larynx were randomized equally into the two arms (SIB-IMRT vs. SEQ-IMRT). Patients in SIB-IMRT arm received dose of 66 Gy in 30 fractions, 5 days a week, over 6 weeks. SEQ-IMRT arm’s patients received 70 Gy in 35 fractions over 7 weeks. Weekly concurrent cisplatin chemotherapy was given in both arms. Patients were assessed for acute toxicities during the treatment and for objective response at 3 months after the radiotherapy. @*Results@#Grade 3 dysphagia was significantly more with SIB-IMRT compared to SEQ-IMRT (72% vs. 41.2%; p = 0.006) but other toxicities including mucositis, dermatitis, xerostomia, weight-loss, incidence of nasogastric tube intubation and hospitalization for supportive management were similar in both the arms. Patients in SIB-IMRT arm showed better treatment-compliance and had significantly less treatment-interruption compared to SEQ-IMRT arm (p = 0.028). Objective response rates were similar in both the arms (p = 0.783). @*Conclusion@#Concurrent chemoradiation with SIB-IMRT for locally advanced head and neck cancer is well-tolerated and results in better treatment-compliance, similar objective response rates, comparable incidence of mucositis and higher incidence of grade 3 dysphagia compared to SEQ-IMRT.
ABSTRACT
Purpose@#Intensity-modulated radiotherapy (IMRT) provides higher dose to target volumes and limits the dose to normal tissues. IMRT may be applied using either simultaneous integrated boost (SIB-IMRT) or sequential boost (SEQ-IMRT) technique. The objectives of this study were to compare acute toxicity and objective response rates between SIB-IMRT and SEQ-IMRT in patients with locally advanced head and neck cancer. @*Materials and Methods@#Total 110 patients with locally advanced carcinoma of oropharynx, hypopharynx, and larynx were randomized equally into the two arms (SIB-IMRT vs. SEQ-IMRT). Patients in SIB-IMRT arm received dose of 66 Gy in 30 fractions, 5 days a week, over 6 weeks. SEQ-IMRT arm’s patients received 70 Gy in 35 fractions over 7 weeks. Weekly concurrent cisplatin chemotherapy was given in both arms. Patients were assessed for acute toxicities during the treatment and for objective response at 3 months after the radiotherapy. @*Results@#Grade 3 dysphagia was significantly more with SIB-IMRT compared to SEQ-IMRT (72% vs. 41.2%; p = 0.006) but other toxicities including mucositis, dermatitis, xerostomia, weight-loss, incidence of nasogastric tube intubation and hospitalization for supportive management were similar in both the arms. Patients in SIB-IMRT arm showed better treatment-compliance and had significantly less treatment-interruption compared to SEQ-IMRT arm (p = 0.028). Objective response rates were similar in both the arms (p = 0.783). @*Conclusion@#Concurrent chemoradiation with SIB-IMRT for locally advanced head and neck cancer is well-tolerated and results in better treatment-compliance, similar objective response rates, comparable incidence of mucositis and higher incidence of grade 3 dysphagia compared to SEQ-IMRT.
ABSTRACT
Introduction and Objective: Anatomic and volumetric changes occur in head-and-neck cancer during fractionated radiotherapy (RT), and the actual dose received by patient is considerably different from the original plan. The purpose of this study is to evaluate volumetric and dosimetric changes occurring during radiation therapy. Patients and Methods: Ten patients of locally advanced head-and-neck cancer, 6 oropharynx, 3 larynx, and 1 hypopharynx underwent computed tomography (CT) simulation before treatment and after 4 weeks during RT treatment. Original plan (OPLAN) was generated based on initial CT scan for the entire course of treatment. The initial plan is implemented on the second planning CT scan, and the dose distribution is recalculated. Beam configuration of OPLAN was applied onto the second CT scan and then hybrid plan (HPLAN30) was generated. RPLAN30 is the intensity-modulated RT replan generated on the second CT scan for the remaining 30 Gy. Dose and volume parameters between OPLAN30 (based on the first CT scan for the remaining 30 Gy), HPLAN30, and RPLAN30 were compared. Results: The volume reduction of planning target volume (PTV), ipsilateral and contralateral parotid after 4 weeks of RT, was statistically significant (P < 0.05). D2% and V > 107% of PTV were higher in HPLAN than that of RPLAN (P < 0.05). Hybrid plans showed increase in delivered dose to spinal cord. Mid treatment replanning reduced doses to spinal cord (Dmax and D1%), which is statistically significant (P < 0.05). Mean doses to ipsilateral and contralateral parotid of RPLAN (21.4 Gy and 16.74 Gy, respectively) were reduced when compared to that of HPLAN (22.99 Gy and 22 Gy, respectively). Conclusion: Interim CT scanning and replanning (adaptive) improves target volume coverage and normal tissue sparing