Propensity-score-matched evaluation of the incidence of radiation pneumonitis and secondary cancer risk for breast cancer patients treated with IMRT/VMAT

Abstract

Propensity score matching evaluates the treatment incidence of radiation-induced pneumonitis (RP) and secondary cancer risk (SCR) after intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for breast cancer patients. Of 32 patients treated with IMRT and 58 who received VMAT were propensity matched in a 1:1 ratio. RP and SCR were evaluated as the endpoints of acute and chronic toxicity, respectively. Self-fitted normal tissue complication probability (NTCP) parameter values were used to analyze the risk of RP. SCRs were evaluated using the preferred Schneider’s parameterization risk models. The dosimetric parameter of the ipsilateral lung volume receiving 40 Gy (IV40) was selected as the dominant risk factor for the RP NTCP model. The results showed that the risks of RP and NTCP, as well as that of SCR of the ipsilateral lung, were slightly lower than the values in patients treated with VMAT versus IMRT (p ≤ 0.01). However, the organ equivalent dose and excess absolute risk values in the contralateral lung and breast were slightly higher with VMAT than with IMRT (p ≤ 0.05). When compared to IMRT, VMAT is a rational radiotherapy option for breast cancer patients, based on its reduced potential for inducing secondary malignancies and RP complications.

Radiation-induced lung toxicity – cellular and molecular mechanisms of pathogenesis, management, and literature review

“…Several diagnostic and therapeutic advances, such as PETimaging [3,4], improved radiation delivery techniques [5][6][7][8][9], implementation of immunotherapy [10][11][12][13][14][15][16], and molecularly targeted therapy [17][18][19], have led to improved outcome in terms of overall survival, local and distant control as well as quality of life. However, between 10 and 30% of all patients with lung or breast cancer receiving thoracic radiotherapy develop radiation-induced pneumonitis (RIP) as a subacute treatment-associated toxicity, and they are at high risk of developing radiation-induced lung fibrosis (RILF) as late toxicity, although treatmentrelated death is uncommon [5,[20][21][22][23][24].…”

Toxicity after volumetric modulated arc therapy for lung cancer: a monocentric retrospective study

“…For volumetric modulated arc therapy (VMAT), this low dose bath, reflected by the V5% to the lungs, has raised even more concerns. In addition to the higher theoretical risk of developing secondary malignancy (13,14), the rate of radiological pneumonitis may be higher in patients treated with VMAT compared with conformal 3D-RT (15,16). However, reported results are contradictory in terms of occurrence of lung complications following IMRT or VMAT (17,18).…”

The Impact of Radiotherapy on the Incidence of Secondary Malignancies: A Pan-Cancer Study in the US SEER Cancer Registries

“…Except for some genetic and environmental risk factors, treatment methods were also associated with the occurrence of secondary malignancies [ 1 ]. Though controversies still existed, some previous studies have observed independent associations of radiotherapy and SPMs in some tumor types, including tumors originated from the prostate, [ 6 , 9 , 10 ] breast, [ 7 , 11 , 12 , 13 ] rectum [ 14 ], and uterus [ 15 , 16 ]. However, previous publications have not involved some common cancer types, such as tumors from the esophagus, stomach, and urinary bladder.…”