Pavan M. Jhaveri

A dose-response relationship for time to bone pain resolution after stereotactic body radiotherapy (SBRT) for renal cell carcinoma (RCC) bony metastases

Abstract Background. To investigate the utility of stereotactic body radiotherapy (SBRT) in the treatment of painful renal cell carcinoma (RCC) bone metastases, and for a possible dose effect on time to symptom relief. Material and methods. Eighteen patients with 24 painful osseous lesions from metastatic RCC were treated with SBRT. The most common treatment regimens were 24 Gy in 3 fractions and 40 Gy in 5 fractions. The times from treatment to first reported pain relief and time to symptom recurrence were evaluated. Median follow-up was 38 weeks (1–156 weeks). Results. Seventy-eight percent of all patients had pain relief. Patients treated with a BED > 85 Gy achieved faster and more durable pain relief compared to those treated with a BED < 85 Gy. There was decrease in time to pain relief after a change in treatment regimen to 8 Gy × 5 fractions (BED = 86). There was only one patient with grade 1 skin toxicity. No neurological or other toxicity was observed. Conclusions. SBRT can safely and effectively treat painful RCC bony metastases. There appears to be a relationship between radiation dose and time to stable pain relief.

Is there an increase in genitourinary toxicity in patients treated with transurethral resection of the prostate and radiotherapy? A systematic review.

Purpose:Transurethral resection of the prostate (TURP) is considered by some as a risk factor for genitourinary (GU) toxicity after radiotherapy (RT). However, there are conflicting results regarding the interaction between RT and TURP with respect to GU toxicity. The purpose of this report is to review the published data concerning TURP before or after RT and its effect on urinary complication. Methods and Materials:A systematic literature review based on database searches in MEDLINE, EMBASE, Pubmed, Ovid, and Chochrane Library. The eligibility criteria of final review were (1) definitive RT for prostate cancer is reported; (2) comparison of GU toxicities between patients with and without TURP is reported; (3) minimum 5 patients after TURP are included. Results:Twelve articles regarding overall GU toxicity, 15 articles regarding urinary incontinence, and 13 articles regarding urinary or bladder neck stricture met eligibility criteria, and they were included in the final review. A quantitative synthesis from the data of selected articles was impossible because of variable grading systems and variable definitions in their comparisons between patients with and without TURP. However, most published articles demonstrated the increased risk of GU toxicity with TURP in patients treated with RT. Conclusions:Our systematic review strongly suggests that TURP is one of the risk factors of GU toxicity after RT. This needs to be taken seriously when prostate cancer patients with TURP are considered for RT either external beam or brachytherapy.

Emergence of integrated urology-radiation oncology practices in the state of Texas

PURPOSE Integrated urology-radiation oncology (RO) practices have been advocated as a means to improve community-based prostate cancer care by joining urologic and radiation care in a single-practice environment. However, little is known regarding the scope and actual physical integration of such practices. We sought to characterize the emergence of such practices in Texas, their extent of physical integration, and their potential effect on patient travel times for radiation therapy. METHODS AND MATERIALS A telephone survey identified integrated urology-RO practices, defined as practices owned by urologists that offer RO services. Geographic information software was used to determine the proximity of integrated urology-RO clinic sites with respect to the states population. We calculated patient travel time and distance from each integrated urology-RO clinic offering urologic services to the RO treatment facility owned by the integrated practice and to the nearest nonintegrated (independent) RO facility. We compared these times and distances using the Wilcoxon-Mann-Whitney test. RESULTS Of 229 urology practices identified, 12 (5%) offered integrated RO services, and 182 (28%) of 640 Texas urologists worked in such practices. Approximately 53% of the state population resides within 10 miles of an integrated urology-RO clinic site. Patients with a diagnosis of prostate cancer at an integrated urology-RO clinic site travel a mean of 19.7 miles (26.1 min) from the clinic to reach the RO facility owned by the integrated urology-RO practice vs 5.9 miles (9.2 min) to reach the nearest nonintegrated RO facility (P<.001). CONCLUSIONS Integrated urology-RO practices are common in Texas and are generally clustered in urban areas. In most integrated practices, the urology clinics and the integrated RO facilities are not at the same location, and driving times and distances from the clinic to the integrated RO facility exceed those from the clinic to the nearest nonintegrated RO facility.

Helical Tomotherapy Significantly Reduces Dose to Normal Tissues When Compared to 3D-CRT for Locally Advanced Rectal Cancer

Combined modality treatment (neoadjuvant chemoradiotherapy followed by surgery) for locally advanced rectal cancer requires special attention to various organs at risk (OAR). As a result, the use of conformal dose delivery methods has become more common in this disease setting. Helical tomotherapy is an image-guided intensity modulated delivery system that delivers dose in a fan-beam manner at 7 degree intervals around the patient and can potentially limit normal tissue from high dose radiation while adequately treating targets. In this study we dosimetrically compare helical tomotherapy to 3D-CRT for stage T3 rectal cancer. The helical tomotherapy plans were optimized in the TomoPlan system to achieve an equivalent uniform dose of 45 Gy for 10 patients with T3N0M0 disease that was at least 5cm from the anal verge. The GTV included the rectal thickening and mass evident on colonoscopy and CT scan as well as with the help of a colorectal surgeon. The CTV included the internal iliac, obturator, and pre-sacral lymphatic chains. The OAR that were outlined included the small bowel, pelvic bone marrow, femoral heads, and bladder. Anatom-e system was used to assist in delineating GTV, CTV and OAR. These 10 plans were then duplicated and optimized into 3-field 3D-CRT plans within the Pinnacle planning system. The V[45], V[40], V[30], V[20], V[10], and mean dose to the OAR were compared between the helical tomotherapy and 3D-CRT plans. Statistically significant differences were achieved in the doses to all OAR, including all volumes and means except for V[10] for the small bowel and the femoral heads. Adequate dosimetric coverage of targets were achieved with both helical tomotherapy and 3D-CRT. Helical tomotherapy reduces the volume of normal tissue receiving high-dose RT when compared to 3D-CRT treatment. Both modalities adequately dose the tumor. Clinical studies addressing the dosimetric benefits are on-going.

Height impairment after lower dose cranial irradiation in children with acute lymphoblastic leukemia

The purpose of this study is to determine whether height measurements are affected by cranial radiation doses of 12–18 Gy.

Anticancer therapy and lung injury: molecular mechanisms

ABSTRACT Introduction: Chemotherapy and radiation therapy are two mainstream strategies applied in the treatment of cancer that is not operable. Patients with hematological or solid tumor malignancies substantially benefit from chemotherapeutic drugs and/or ionizing radiation delivered to the site of malignancy. However, considerable adverse effects, including lung inflammation and fibrosis, are associated with the use of these treatment modalities. Areas covered: As we move toward the era of precision health, we are compelled to understand the molecular basis of chemoradiation-induced pathological lung remodeling and to develop effective treatment strategies that mitigate the development of chronic lung disease (i.e. fibrosis) in cancer patients. The review discusses chemotherapeutic agents that are reported to induce or associate with acute and/or chronic lung injury. Expert commentary: There is a need to molecularly understand how chemotherapeutic drugs induce or associate with respiratory toxicities and whether such characteristics are inherently related to their antitumor effect or are collateral. Once such mechanisms have been identified and/or fully characterized, they may be able to guide disease-management decisions including effective intervention strategies for the adverse effects. In the meantime, radiation oncologists should be judicious on the dose of radiation delivered to the lungs, the volume of lung irradiated, and concurrent use of chemotherapeutic drugs.