Characterization of combined intracavitary/interstitial brachytherapy including oblique needles in locally advanced cervix cancer.

PURPOSE: To characterize and report on dosimetric outcomes of image guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) applicators including oblique needles (O-needles) in locally advanced cervical cancer (LACC). METHODS AND MATERIALS: Twenty LACC patients treated with radio-chemotherapy and offered IC/IS-IGABT including O-needles were analyzed. An in-house 3D-printed vaginal template was used to steer the needles parallel and obliquely in relation to the tandem, supplemented with free-hand needles if needed. Implant characteristics and loading patterns were analyzed. Using the equivalent dose in 2Gy-fractions (EQD2) concept, cumulative (EBRT+BT) V85, V75, V60Gy, targets/OARs doses and high dose volumes (150%, 200% and 300% (100% = 85 Gy EQD210)) were evaluated. RESULTS: Median(range) tumor width at diagnosis was 5.5(3.6; 7.5)cm; CTVHR volume was 45(23; 136)cm3 with maximum distance from tandem to CTVHR border of 3.4(2.5; 4.8)cm. T-stage distribution was IIB/III/IVA in 6(30%)/9(45%)/5(25%) of patients. At BT, 13(65%) patients had distal parametrial/pelvic wall infiltration. Median(range) number of needles per patient was 11(8-18). Average distribution of intrauterine, vaginal and interstitial dwell times were 31%, 25% and 44%, respectively. Median(range) dwell-time per dwell position was 11(2-127)% of average point-A based standard loading. Median V85Gy/V150%/V200%/V300% were 85(38; 171)/41(21; 93)/22(12; 41)/7(4; 19) cm3; CTVHR D90% was 93(83; 97)Gy EQD210; bladder/rectum/sigmoid/bowel D2cm3 were 78(64; 104)/65(52; 76)/59(53; 69)/61(47; 76)Gy EQD23. CONCLUSIONS: The use of O-needles in patients with large and/or unfavorable tumors resulted in excellent target coverage and OARs sparing. Intrauterine and vaginal loadings were reduced compared to standard loading and almost half of the loading was shifted into IS needles. This was achieved with gentle loading in the majority of dwell positions.

Stereotactic body radiotherapy for unresectable cholangiocarcinoma.

PURPOSE: To report outcomes of a single institution study of stereotactic body radiotherapy (SBRT) for unresectable cholangiocarcinoma. The dose-volume dependency of the observed gastrointestinal toxicity is explored. METHODS AND MATERIALS: Twenty-seven patients with unresectable cholangiocarcinoma (n=26 Klatskin tumours and one intrahepatic cholangiocarcinoma (IHCC)) were treated by linac-based SBRT. The dose schedule was 45Gy in three fractions prescribed to the isocenter. RESULTS: The median progression-free survival and overall survival were 6.7 and 10.6 months, respectively. With a median follow-up of 5.4 years, 6 patients had severe duodenal/pyloric ulceration and 3 patients developed duodenal stenosis. Duodenal radiation exposure was higher in patients developing moderate to high-grade gastrointestinal toxicity with the difference in mean maximum dose to 1cm(3) of duodenum reaching statistical significance. A statistically significant association between grade 2 ulceration and volume of duodenum exposed to selected dose levels was not established. CONCLUSION: The outcomes of SBRT for unresectable cholangiocarcinoma appear comparable to conventionally fractionated chemoradiotherapy with or without brachytherapy boost. The practical advantages of SBRT are of particular interest for such poor prognosis patients. Patient selection, however, is key in order to avoid compromising such practical gains with excessive gastrointestinal toxicity.

Co-morbidity index predicts for mortality after stereotactic body radiotherapy for medically inoperable early-stage non-small cell lung cancer.

PURPOSE: To determine the prognostic role of co-morbidity in medically inoperable early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). METHODS AND MATERIALS: Between 2000 and 2007, 88 consecutive early-stage medically inoperable NSCLC patients were treated by linac-based SBRT. The dose was either 45 Gy or 67.5 Gy in three fractions prescribed to the isocenter. Baseline co-morbidities were retrospectively retrieved by consultation of a formal electronic registry of diagnoses as well as patients' charts. The age-adjusted Charlson Co-morbidity Index (CCI) was scored for each patient and subjected to univariate and multivariate analysis. RESULTS: With a median follow-up of 44 months, the actuarial local control rate at 4 years was 89% while the median overall survival was 22 months. The median age-adjusted CCI score was 5. The age-adjusted CCI was a significant predictor of overall survival on both univariate (p=0.002) and multivariate analysis (p=0.011). Patients with an age-adjusted CCI score of 3 or less had a median survival of 41 months versus only 11 months for those scoring 6 or more. CONCLUSION: The number and seriousness of co-morbidities predict overall survival in medically inoperable early-stage NSCLC treated with SBRT. Because the determination of medical operability is frequently based on both objective measures and subjective clinical judgment, it is recommended that co-morbidity be formally indexed in all studies examining the outcomes of SBRT.