Nitesh N. Paryani

Extranodal Rosai-Dorfman disease of the bone treated with surgery and radiotherapy

Rosai-Dorfman disease (RDD) is a rare, benign histiocyte disorder originally described by Rosai and Dorfman in 1969 as sinus histiocytosis with massive lymphadenopathy. It most typically presents as massive, painless cervical lymphadenopathy, and it is most often found in adolescents and young adults. Extranodal involvement is a common feature of RDD and may occur in more than 40% of patients. Less commonly, the disease can be seen in the bone. There are scattered case reports discussing the use of radiotherapy in the treatment of RDD. Here, we present a case of extranodal RDD of the femur in a 49-year-old African American female. The patient underwent three surgical procedures prior to undergoing radiotherapy. Pathology was consistent with extranodal RDD. The cells stained positive for CD68 and S-100. Pathognomonic features such as emperipolesis and replacement of the bone marrow by diffuse infiltrating of histiocytes and intervening bands of plasma cells proliferation were noted. Prior to radiotherapy, the patient required a walker to assist with ambulation and was utilizing a wheelchair while in the clinic. The decision was made to proceed with 30 Gy of external beam radiotherapy in 15 fractions. After five fractions, the patient’s pain resolved entirely. She no longer required pain medication and was ambulating without assistance. She experienced no adverse events from the radiation. Extranodal RDD is a rare disorder, and evidence for treatment is derived from scattered case reports. Previous reports have indicated a dose response to radiotherapy in the 20-30 Gy range for RDD; however, our patient developed complete resolution of her symptoms after 10 Gy. While the optimal dose regimen has not yet been established, symptomatic patients appear to benefit from external beam radiotherapy for extranodal RDD.

Evaluation of Serum Calcium as a Predictor of Biochemical Recurrence following Salvage Radiation Therapy for Prostate Cancer

Background. Previous reports have shown a positive association between serum calcium level and prostate cancer mortality. However, there is no data regarding whether higher serum calcium levels are associated with increased risk of biochemical recurrence (BCR) following salvage radiation therapy (SRT) for prostate cancer. Herein, we evaluate the association between pretreatment serum calcium levels and BCR in a cohort of men who underwent SRT. Methods. We evaluated 165 patients who underwent SRT at our institution. Median dose was 65.0 Gy (range: 54.0–72.4 Gy). We considered serum calcium as both a continuous variable and a 3-level categorical variable (low [≤9.0 mg/dL], moderate [>9.0 mg/dL and ≤9.35 mg/dL], and high [>9.35 mg/dL]) based on sample tertiles. Results. We observed no evidence of a linear association between serum calcium and BCR (relative risk (RR): 0.96, P = 0.76). Compared to men with low calcium, there was no significantly increased risk of BCR for men with moderate (RR: 0.94, P = 0.79) or high (RR: 1.08, P = 0.76) serum calcium levels. Adjustment for clinical, pathological, and SRT characteristics in multivariable analyses did not alter these findings. Conclusion. Our results provide evidence that pretreatment serum calcium is unlikely to be a useful tool in predicting BCR risk following SRT.

Stereotactic Body Radiotherapy for Medically Inoperable Stage I-II Non–Small Cell Lung Cancer: The Mayo Clinic Experience

Objective To examine disease control and survival after stereotactic body radiotherapy (SBRT) for medically inoperable, early-stage non–small cell lung cancer (NSCLC) and determine associations of pretreatment 18F-fluorodeoxyglucose–positron emission tomography (FDG-PET) maximum standardized uptake values (SUVmax), biologically effective dose, and mediastinal staging with disease control and survival outcomes. Patients and Methods We retrospectively reviewed the cases of consecutive patients with FDG-PET–staged, medically inoperable NSCLC treated with SBRT at our institution between January 1, 2008, and August 4, 2014. Cumulative incidences of recurrence were estimated, accounting for the competing risk of death. Associations of SUVmax, biologically effective dose, and mediastinal staging with outcomes were evaluated using Cox proportional hazards regression models. Results Among 282 patients, 2-year cumulative incidences of recurrence were 4.9% (95% CI, 2.6%-8.3%) for local, 9.8% (95% CI, 6.3%-14.2%) for nodal, 10.8% (95% CI, 7.0%-15.5%) for ipsilateral lung, 6.0% (3.3%-9.8%) for contralateral lung, 9.7% (95% CI, 6.3%-14.0%) for distant recurrence, and 26.1% (95% CI, 20.4%-32.0%) for any recurrence. The 2-year overall survival was 70.4% (95% CI, 64.5%-76.8%), and the 2-year disease-free survival was 51.2% (95% CI, 44.9%-58.5%). Risk of any recurrence was significantly higher for patients with higher SUVmax (hazard ratio [per each doubling], 1.29 [95% CI, 1.05-1.59]; P=.02). A similar association with SUVmax was observed when considering the composite outcome of any recurrence or death (hazard ratio, 1.23 [95% CI, 1.05-1.44]; P=.01). The SUVmax was not significantly associated with other outcomes (P≥0.69). Two-year cumulative incidences of local recurrence for patients receiving 48 Gy in 4 fractions, 54 Gy in 3 fractions, or 50 Gy in 5 fractions were 1.7% (95% CI, 0.3%-5.6%), 3.7% (95% CI, 0.7%-11.4%), and 15.3% (95% CI, 5.9%-28.9%), respectively (P=.02); this difference was independent of lesion size (P=.02). Conclusion Disease control was excellent for patients who received SBRT for early-stage NSCLC, and this series represents the largest single-institution experience from the United States on SBRT for early-stage inoperable NSCLC. Higher pretreatment FDG-PET SUVmax was associated with increased risk of any recurrence, and the 50 Gy in 5 fractions dose prescription was associated with increased risk of local recurrence.

Proposed prognostic scoring system evaluating risk factors for biochemical recurrence of prostate cancer after salvage radiation therapy.

To update a previously proposed prognostic scoring system that predicts risk of biochemical recurrence (BCR) after salvage radiation therapy (SRT) for recurrent prostate cancer when using additional patients and a PSA value of 0.2 ng/mL and rising as the definition of BCR.