Evaluation of clinically involved lymph nodes with deformable registration in breast cancer radiotherapy.

OBJECTIVES: Modern radiotherapy (RT) techniques require careful delineation of the target. There is no particular RT contouring guideline for patients receiving neoadjuvant chemotherapy (NACT). In this study, we examined the distribution of pre-chemotherapy clinically positive nodal metastases. METHODS: We explored the coverage rate of the RTOG breast contouring guideline by deformable fusion of 18-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scan. We retrospectively evaluated neoadjuvant chemotherapy patients. All PET-CT images were imported into the planning software. We combined the planning CT and the CT images of PET-CT with rigid and then a deformable registration. We manually contoured positive lymph nodes on the CT component of the PET-CT data set and transferred them to planning CT after fusion. We evaluated whether previously contoured lymphatic CTVs, according to the RTOG breast atlas, include GTV-LNs. RESULTS: All breast cancer patients between October 2018 and February 2021 were evaluated from the electronic database. There were 142 radiologically defined positive lymph nodes in 31 patients who were irradiated after NACT. Most LNs (70%) were in the level I axilla. Only 71.1% (n:101) of the whole lymph nodes in 10 patients were totally covered, 22.5% (n:32) partially covered and 6.4% %(n:9) totally undercovered. CONCLUSIONS: The extent of regional nodal areas in the RTOG atlas may be insufficient to cover positive lymph nodes adequately. For patients with nodal involvement undergoing neoadjuvant chemotherapy, PET-CT image fusions can be helpful to be sure that positive lymph nodes are in the treatment volume. ADVANCES IN KNOWLEDGE: RTOG contouring atlas may be insufficient to cover all involved lymph nodes after NACT. For patients with nodal involvement undergoing neoadjuvant chemotherapy, PET-CT image fusions may help to be sure that positive lymph nodes are in the treatment volume.

Stereotactic body radiotherapy in patients with adrenal gland metastases of oligometastatic and oliogoprogressive lung cancer.

Objective: To evaluate the efficacy and safety of stereotactic body radiotherapy (SBRT) in patients with adrenal gland metastasis (AGM) of oligometastatic lung cancer. Methods: Between June 2013 and May 2021, 44 patients with oligometastatic lung cancer (51 AGMs) were treated with SBRT. Forty-six (90%) lesions received a biological effective dose (BED10, α/ß = 10) of 100 Gy. The primary endpoint was local control (LC). Local control (LC), overall survival (OS), and progression-free survival (PFS) curves were calculated by the Kaplan-Meier method. Results: The median follow-up was 23 months. The most common histology was non-small cell lung cancer (88.6%). The 1- and 2-year LC rates were both 95% and 91%, respectively. Overall survival was better in patients with solitary AGMs in univariate analysis. Conclusion: This study demonstrated that SBRT with higher BED is associated with satisfactory LC and low toxicity rates in patients with AGM of oligometastatic lung cancer.