Outcome and toxicity of stereotactic body radiotherapy with helical tomotherapy for inoperable lung tumor: analysis of Grade 5 radiation pneumonitis

Abstract

To analyze outcomes and toxicities of stereotactic body radiotherapy with helical tomotherapy (HT-SBRT) for inoperable lung tumors, the medical records of 30 patients with 31 lung tumors treated with HT-SBRT were reviewed. The 3-year local control, cause-specific survival and overall survival rates (LC, CCS and OS, respectively) were analyzed using the Kaplan–Meier method. Toxicities were graded using Common Terminology Criteria for Adverse Events ver. 4. To investigate the factors associated with Grade 5 radiation pneumonitis (G5 RP), several parameters were analyzed: (i) patient-specific factors (age, gross tumor volume and PTV, and the interstitial pulmonary shadow on pretreatment CT); and (ii) dosimetry-specific factors (conformity index, homogeneity index, mean lung dose, and V5, V10, V15, V20 and V25 of the total lungs). The median duration of observation for all patients was 36.5 months (range, 4–67 months). The 3-year LC, CCS and OS were 82, 84 and 77%, respectively. Regarding Grade 3 or higher toxicities, two patients (6.7%) developed G5 RP. GTV was significantly associated with G5 RP (P = 0.025), and there were non-significant but slight associations with developing G5 RP for V5 (P = 0.067) and PTV (P = 0.096). HT-SBRT led to standard values of LC, CCS and OS, but also caused a markedly higher incidence of G5 RP. It is essential to optimize patient selection so as to avoid severe radiation pneumonitis in HT-SBRT.

Predicting risk factors for radiation pneumonitis after stereotactic body radiation therapy for primary or metastatic lung tumours

“…14,15,22,23 Recently, the risk factors of RP after SBRT in patients with lung tumours have been investigated, 19,[22][23][24][25][26][27][28][29] and some studies reported about the clinical and dosimetric risk factors of RP. 21,[29][30][31][32][33][34][35][36][37][38][39][40][41][42] Table 7 summarizes published reports of the clinical and dosimetric risk factors associated with Grade 2 or worse RP after SBRT.…”

Treatment outcomes and patterns of radiologic appearance after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) for lung tumours

“…Owing to the aforementioned disadvantages of HT compared with other stereotactic treatments in this setting, HTT is slow to be adopted in clinical practice, and few studies-often evaluating small series of patients with inhomogeneous characteristics and short FU-are available in the recent literature [9][10][11][12][13][14][15][16] (Table 4). Several points can be gleaned from this study, which to our knowledge is one among the largest series addressing the use of HTT in the treatment of lung lesions.…”

“…5,6 While dosimetric findings have shown that such capabilities can potentially translate into the delivery of an increased tumour dose with doses to normal tissues decreased compared with other techniques, 7,8 only a limited number of patients were included in recent studies that have addressed the feasibility of hypofractionated or ablative radiotherapy (RT) regimens for lung tumours treated with HT. [9][10][11][12][13][14][15][16] Reasonable arguments might be advocated for its slow adoption in the clinical practice in this setting: during HT it is not only the tumour and the MLC that are moving but also the radiation source and couch, which can maximize the breathing interplay effect (i.e. difference between planned and delivered absorbed doses that arises from a mismatch between the tumour and the MLC because of motion).…”

Efficacy of the Dynamic Jaw Mode in Helical Tomotherapy With Static Ports for Breast Cancer

“…The reduction of the lung volume receiving lower dose may reduce the possibility of radiation pneumonitis. 23 …”