Intensity-Modulated Radiation Therapy With or Without Chemotherapy for Nasopharyngeal Carcinoma: Radiation Therapy Oncology Group Phase II Trial 0225

Abstract

A B S T R A C T PurposeTo investigate the feasibility of intensity-modulated radiation therapy (IMRT) with or without chemotherapy, and to assess toxicities, failure patterns, and survivals in patients with nasopharyngeal carcinoma (NPC). Patients and MethodsRadiation consisted of 70 Gy given to the planning target volumes of primary tumor plus any Nϩ disease and 59.4 Gy given to subclinical disease, delivered over 33 treatment days. Patients with stage T2b or greater or with Nϩ disease also received concurrent cisplatin (100 mg/m 2 ) on days 1, 22, and 43 followed by adjuvant cisplatin (80 mg/m 2 ) on day 1; fluorouracil (1,000 mg/m 2 /d) on days 1 through 4 administered every 4 weeks for three cycles. Tumor, clinical status, and acute/late toxicities were assessed. The primary objective was to test the transportability of IMRT to a multi-institutional setting. February 2003 and November 2005, 68 patients with stages I through IVB NPC (of which 93.8% were WHO types 2 and 3) were enrolled. Prescribed IMRT (target delineation) was given to 83.8%, whereas 64.9% received chemotherapy per protocol. The estimated 2-year local progression-free (PF), regional PF, locoregional PF, and distant metastasis-free rates were 92.6%, 90.8%, 89.3%, and 84.7%, respectively. The estimated 2-year PF and overall survivals were 72.7% and 80.2%, respectively. Acute grade 4 mucositis occurred in 4.4%, and the worst late grade 3 toxicities were as follows: esophagus, 4.7%; mucous membranes, 3.1%; and xerostomia, 3.1%. The rate of grade 2 xerostomia at 1 year from start of IMRT was 13.5%. Only two patients complained of grade 3 xerostomia, and none had grade 4 xerostomia. Results Between ConclusionIt was feasible to transport IMRT with or without chemotherapy in the treatment of NPC to a multi-institutional setting with 90% LRPF rate reproducing excellent reports from single institutions. Minimal grade 3 and lack of grade 4 xerostomia were encouraging.

Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator

“…The planning target volume (PTV) was the expanded tumor region, which means the former tumor region (GTV = gross tumor region), including two centimeter of automatically generated safety margin taking into account anatomical limits or rearrangement of brain tissue into the resection area after surgery. Dose threshold was based on the tolerance doses for organs at risk (OAR) of the protocol of Radiation Therapy Oncology Group Trial 0225 15. Dose to the normal tissue (patient outline excluding the PTV) should be kept as low as possible to minimize the risk of second cancer induction 8…”

Comparative analysis of SmartArc‐based dual arc volumetric‐modulated arc radiotherapy (VMAT) versus intensity‐modulated radiotherapy (IMRT) for nasopharyngeal carcinoma

“…The PRVs of the brain stem and chiasm were defined through addition of a 3D margin of at least 1 mm around the delineated structures. According to the RTOG 0225, ( 3 , 28 ) the planning objectives for PTVs were at a minimum dose $>95\%$, and no more than 5% of any ${\mathrm{normalPTV}}_{72}$ received $\ge 110\%$ of the prescribed dose. The structural constraints used in this study were as follows: 1) brain stem — maximum dose $\le 54\hspace{0.17em}\text{Gy}$ or 1% of PRV $\le 60\hspace{0.17em}\text{Gy}$; 2) spinal cord — maximum dose $\le 45\hspace{0.17em}\text{Gy}$ or 1 cc of PRV $\le 50\hspace{0.17em}\text{Gy}$; 3) chiasm — maximum dose $\le 54\hspace{0.17em}\text{Gy}$ or maximum dose of PRV $\le 60\hspace{0.17em}\text{Gy}$; 4) parotid — mean dose $\le 26\hspace{0.17em}\text{Gy}$ or ${\mathrm{normalV}}_{30\text{Gy}}\le 50\%$; 5) eyes — maximum dose must be $\le 45\hspace{0.17em}\text{Gy}$; 6) lens — maximum dose must be $\le 10\hspace{0.17em}\text{Gy}$ and as low as possible; 7) mandible — maximum dose must be $\le 70\hspace{0.17em}\text{Gy}$ or 1 cc of PRV and cannot exceed 75 Gy; 8) oral cavity excluding PTV — mean dose must be $\le 40\hspace{0.17em}\text{Gy}$; and 9) healthy tissue — mean dose must be $\le 30\hspace{0.17em}\text{Gy}$ or no more than 1% or 1 cc of the tissue outside the PTV will receive $\ge 110\%$ of the dose prescribed to the PTV.…”

Induction chemotherapy in the treatment of nasopharyngeal carcinoma: Clinical outcomes and patterns of care

“…Furthermore, the use of 3‐dimensional imaging (CT and MRI) along with improvement in RT technology has resulted in excellent local control rates 6. However, distant failure still remains the main source of mortality in this patient population.…”