Brachytherapy improves outcomes in young men (≤60 years) with prostate cancer: A SEER analysis.

PURPOSE: The aim of the study was to compare prostate cancer-specific mortality (PCSM) in young men with clinically localized prostate cancer treated by either external beam radiation (EBRT) alone or brachytherapy with or without external beam radiation. METHODS AND MATERIALS: Utilizing the Surveillance, Epidemiology and End Results database, 15,505 patients ≤60 years of age diagnosed with prostate cancer between 2004 and 2009 and treated with radiation therapy alone were identified. Incidence of PCSM was determined for both groups and compared using competing risk models. RESULTS: The overall 8-year PCSM for the study population was 1.9% (95% confidence interval [CI]: 1.6-2.2). For patients treated with EBRT or brachytherapy with or without external beam, the 8-year PCSM was found to be 2.8% (CI: 2.2-3.4) and 1.2% (CI: 0.9-1.6), respectively (p < 0.001). Univariable analysis demonstrated that brachytherapy was associated with lower PCSM risk (hazard ratio = 0.40; CI: 0.30-0.54; p < 0.001). High Gleason risk category, black race, higher Tumor (T) stage, and higher grade were all associated with greater mortality risk (p < 0.01). On multivariable analysis, brachytherapy continued to be associated with a significantly lower mortality risk (hazard ratio = 0.65; CI: 0.47-0.89; p = 0.008). Subgroup analyses found that among those with Gleason score ≥8, younger patients had increased risk of PCSM (p = 0.001). CONCLUSIONS: In men ≤60 years of age with prostate cancer, radiation therapy continues to offer excellent outcomes. After adjusting for relevant variables, the use of brachytherapy was associated with reduced PCSM compared to treatment with EBRT alone.

The impact of positron emission tomography/computed tomography in edge delineation of gross tumor volume for head and neck cancers.

PURPOSE: To study anatomic biologic contouring (ABC), using a previously described distinct halo, to unify volume contouring methods in treatment planning for head and neck cancers. METHODS AND MATERIALS: Twenty-five patients with head and neck cancer at various sites were planned for radiation therapy using positron emission tomography/computed tomography (PET/CT). The ABC halo was used in all PET/CT scans to contour the gross tumor volume (GTV) edge. The CT-based GTV (GTV-CT) and PET/CT-based GTV (GTV-ABC) were contoured by two independent radiation oncologists. RESULTS: The ABC halo was observed in all patients studied. The halo had a standard unit value of 2.19 +/- 0.28. The mean halo thickness was 2.02 +/- 0.21 mm. Significant volume modification (>or=25%) was seen in 17 of 25 patients (68%) after implementation of GTV-ABC. Concordance among observers was increased with the use of the halo as a guide for GTV determination: 6 patients (24%) had a

The contribution of integrated PET/CT to the evolving definition of treatment volumes in radiation treatment planning in lung cancer.

PURPOSE: Positron emission tomography (PET) with the glucose analog [18F]fluro-2-deoxy-D-glucose (FDG) has been accepted as a valuable tool for the staging of lung cancer, but the use of PET/CT in radiation treatment planning is still not yet clearly defined. By the use of (PET/computed tomography (CT) images in treatment planning, we were able to define a new gross treatment volume using anatomic biologic contour (ABC), delineated directly on PET/CT images. We prospectively addressed three issues in this study: (1) How to contour treatment volumes on PET/CT images, (2) Assessment of the degree of correlation between CT-based gross tumor volume/planning target volume (GTV/PTV) (GTV-CT and PTV-CT) and the corresponding PET/CT-based ABC treatment volumes (GTV-ABC and PTV-ABC), (3) Magnitude of interobserver (radiation oncologist planner) variability in the delineation of ABC treatment volumes (using our contouring method). METHODS AND MATERIALS: Nineteen patients with Stages II-IIIB non-small-cell lung cancer were planned for radiation treatments using a fully integrated PET/CT device. Median patient age was 74 years (range: 52-82 years), and median Karnofsky performance status was 70. Thermoplastic or vacuum-molded immobilization devices required for conformal radiation therapy were custom fabricated for the patient before the injection of [18]f-FDG. Integrated, coregistered PET/CT images were obtained and transferred to the radiation planning workstation (Xeleris). While the PET data remained obscured, a CT-based gross tumor volume (GTV-CT) was delineated by two independent observers. The PTV was obtained by adding a 1.5-cm margin around the GTV. The same volumes were recontoured using PET/CT data and termed GTV-ABC and PTV-ABC, correspondingly. RESULTS: We observed a distinct "halo" around areas of maximal standardized uptake value (SUV). The halo was identified by its distinct color at the periphery of all areas of maximal SUV uptake, independent of PET/CT gain ratio; the halo had an SUV of 2 +/- 0.4 and thickness of 2 mm +/- 0.5 mm. Whereas the center of our contoured treatment volume expressed the maximum SUV level, a steady decline of SUV was noted peripherally until SUV levels of 2 +/- 0.4 were reached at the peripheral edge of our contoured volume, coinciding with the observed halo region. This halo was always included in the contoured GTV-ABC. Because of the contribution of PET/CT to treatment planning, a clinically significant (> or =25%) treatment volume modification was observed between the GTV-CT and GTV-ABC in 10/19 (52%) cases, 5 of which resulted in an increase in GTV-ABC volume vs. GTV-CT. The modification of GTV between CT-based and PET/CT-based treatment planning resulted in an alteration of PTV exceeding 20% in 8 out of 19 patients (42%). Interobserver GTV variability decreased from a mean volume difference of 28.3 cm3 (in CT-based planning) to 9.12 cm3 (in PET/CT-based planning) with a respective decrease in standard deviation (SD) from 20.99 to 6.47. Interobserver PTV variability also decreased from 69.8 cm3 (SD +/- 82.76) in CT-based planning to 23.9 cm3 (SD +/- 15.31) with the use of PET/CT in planning. The concordance in treatment planning between observers was increased by the use of PET/CT; 16 (84%) had < or =10% difference from mean of GTVs using PET/CT compared to 7 cases (37%) using CT alone (p = 0.0035). CONCLUSION: Position emission tomography/CT-based radiation treatment planning is a useful tool resulting in modification of GTV in 52% and improvement of interobserver variability up to 84%. The use of PET/CT-based ABC can potentially replace the use of GTV. The anatomic biologic halo can be used for delineation of volumes.

Unusual radiation response of gemcitabine-treated HeLa cells: reduced and enhanced survival.

Gemcitabine, a widely reported radiosensitizer, was found to increase and decrease radiation survival of HeLa cells under different treatment conditions. A 24 h exposure at 10 or 20 nM increased S phase cells and radiation survival, with a dose modification factor (DMF) of 0.82 or 0.78, respectively. Shortening exposure time avoided cell cycle effect and eliminated increases of radiation survival. Treatment for 1 h showed no change in radioresponse (DMF of 1.03) at 20 nM versus radiosensitization at 1, 2, or 20 microM (DMF of 1.66). These results document an enhanced radiation survival while confirming reported radiosensitization under different conditions. Such findings may impact drug dosimetry.

Radioactive gold grain implants in recurrent and locally advanced head-and-neck cancers.

PURPOSE: The radioactive gold grain applicator and seeds offer the flexibility necessary for effective use in the treatment of difficult sites of head-and-neck cancers. This study reviews our experience with gold grain (198Au) implants in locally advanced head-and-neck cancer to demonstrate their efficacy and feasibility. METHODS AND MATERIALS: This study reviewed the charts of 94 patients who were treated with gold grain implants (1970-1995) and who were treated with radioactive 198Au implants. Thirty-seven of the subjects had implants located in the head-and-neck region, and these form the basis for this report. Of these, eight of the cases were located in the supraglottic larynx, five in the nasopharynx, four in the retromolar trigone, two in the oral cavity, four in the base of the tongue, four in the maxillary antrum, four in the palate, two in metastatic cervical lymph nodes (of unknown primary tumor), two in the tonsillar fossa, one in the pyriform fossa, and one in the posterior pharyngeal wall. Twenty-eight were recurrent cases after prior surgeries and radiation. Six were residual locally advanced cases, and 3 patients had their implants for a second primary tumor in an area that had been irradiated before. The gold grains were inserted with a Royal Marsden gun and 198Au, 130-180 MBq per seed. The median number of seeds implanted was 34. The total radiation dose, delivered at a margin of 0.5 cm around the target volume, ranged from 40 to 120 Gy, with a median of 80 Gy. RESULTS: Complete local control was achieved in 33% and was contingent on two factors: (1) the size of the lesion implanted and (2) the histology and possible primary tumor site. In 19 tumors with a diameter greater than 2.5 cm, only 2 (11%) had complete tumor control. Conversely, 9 of 14 patients (64%) who had lesions smaller than 2.5 cm experienced successful local control (p = 0.002). Palatal-adenoid-cystic tumors had an average progression-free survival of 52 months, compared with 13, 9, and 4 months, respectively, in nasopharyngeal, oropharyngeal, and supraglottic squamous cell carcinoma. Palliation was successfully accomplished in 76% of the cases. Cessation of bleeding occurred in 50% of the subjects, pain control was achieved in 88%, and 60% experienced relief of dysphagia. CONCLUSIONS: Gold grain implants have a role in the palliation of recurrent head-and-neck tumors, particularly for sites difficult to reach via other techniques, such as the supraglottic larynx, base of the tongue, hypopharynx, and the nasopharynx. Local control is best achieved in lesions less than 2.5 cm in dimension and is most successful in slow-growing tumors.