Tumor Voxel Dose-Response Matrix Prediction Using Deep Learning

PURPOSE/OBJECTIVE(S)

Tumor voxel dose-response matrix (DRM) can be assessed using a series of FDG-PET/CT feedback images acquired during radiotherapy. Predicting the tumor voxel DRM earlier is crucial for effectively implementing adaptive treatment management. However, it is also challenging due to FDG uptake dynamic fluctuation in tumor cells. This study investigated the feasibility of predicting tumor voxel DRM during the early treatment weeks using the advanced deep learning (DL) technique.

MATERIALS/METHODS

Serial FDG-PET/CT images were acquired at the pretreatment (pre-Tx), the 2nd and 4th treatment weeks during standard chemo-radiotherapy (35 × 2 Gy) from each of the 50 patients with head and neck squamous cell carcinomas (HNSCC). The reference value of tumor voxel DRM (DRMref), representing the average metabolic change ratio during the treatment, was determined using a linear regression performed on the standard uptake values (SUV)s obtained at the pre-Tx (SUV0), the 2nd (SUV2) and the 4th (SUV4) treatment weeks following deformable PET/CT image registration. A DL model, 3D residual-Unet with a total of 3.4 million parameters, was trained to predict the tumor voxel DRMref with using the SUV0 and SUV2 matrices as inputs. The performance of the DL model was evaluated using 10-fold cross-validation and was compared to that of a linear regression (LR) model determined on the SUV0 and SUV2 matrices.

RESULTS

The mean (SD) of the tumor voxel DRMref was 0.46 (0.2) over all 34612 tumor voxels. The predicted tumor voxel DRM was 0.5 (0.38) and 0.46 (0.15) for the LR model and the DL model, respectively. For those resistant voxels (23.7% of all tumor voxels) with a DRMref > 0.6, the DRM deviation was 0.13 (0.4) and -0.11 (0.13) for the LR model and the DL model, respectively. For those sensitive voxels (76.3%) with a DRMref ≤ 0.6, the DRM deviation was 0.01 (0.23) and 0.03 (0.08) for the LR model and the DL model, respectively.

CONCLUSION

The proposed DL model can predict the tumor voxel DRM with a single FDG-PET feedback image acquired during the 2nd treatment week of radiotherapy for HNSCC patients. The prediction accuracy was improved compared to that of the LR model with a substantial reduction in the variances of the prediction errors. This work demonstrates the great potential of utilizing DL techniques to improve the efficiency of tumor response assessment and adaptive treatment management.

Long-Term Outcomes Associated with Different High-Dose-Rate Brachytherapy Dose Regimens for Favorable and Unfavorable Intermediate Risk Prostate Cancer

PURPOSE/OBJECTIVE(S)

To present long-term efficacy outcomes of prostate high-dose-rate (HDR) brachytherapy monotherapy using 38 Gy in 4 fractions, 24 Gy in 2 fractions, and 27 Gy in 2 fractions for men with favorable and unfavorable intermediate risk prostate cancer.

MATERIALS/METHODS

Patients treated with HDR brachytherapy monotherapy for NCCN favorable (FIR) or unfavorable (UIR) intermediate risk prostate cancer from 1999-2020 were identified in a prospectively maintained, single institution database. Patients with less than two years of follow-up and those treated with single fraction HDR brachytherapy were excluded. Biochemical failure was determined using Phoenix criteria. 10-year biochemical control (BC), local control (LC), and distant metastasis (DM) rates were estimated using the Kaplan-Meier method.

RESULTS

Two hundred sixty-seven patients were included. One hundred eighty-nine had FIR and 78 had UIR prostate cancer, with median follow-up of 9.6 years and 7.2 years, respectively. Of the 189 patients with FIR prostate cancer, 59 (31.2%) received 38 Gy in 4 fractions, 26 (13.7%) received 24 Gy in 2 fractions, and 104 (55.0%) received 27 Gy in 2 fractions. Of the 78 patients with UIR prostate cancer, 20 (25.6%) received 38 Gy in 4 fractions, 11 (14.1%) received 24 Gy in 2 fractions, and 47 (60.2%) received 27 Gy in 2 fractions. Date ranges of treatment for the respective fractionation schedules were 1999-2010, 2007-2016, and 2009-2020. Upfront androgen deprivation therapy (ADT) was given to 12 (6.3%) patients with FIR and 10 (12.8%) patients with UIR. 10-year rates of BC for FIR and UIR patients were 90.1% and 78.8% (p = 0.004), respectively. 10-year rates of LC were 92.4% and 85.0% (p = 0.06), respectively. 10-year rates of DM were 1.9% and 4.7% (p = 0.12), respectively. For FIR patients, 10-year BC rates were 96.2% for patients receiving 38 Gy in 4 fractions vs. 86.3% (p = 0.07) for those treated with the 2-fraction regimens, while 10-year LC rates were 97.9% and 89.0% (p = 0.049), respectively. Within the UIR subset, the 10-year BC rates for patients receiving 38 Gy in 4 fractions and patients receiving treatment in 2 fractions were 95.0% and 70.6% (p = 0.038). 10-year LC rates were 100% and 77.8% (p = 0.045), respectively. 10-year BC rates by treatment schedule are shown in the table below.

CONCLUSION

HDR brachytherapy monotherapy results in excellent long-term local control for intermediate risk prostate cancer. Improvements in biochemical and local disease control for patients treated with 38 Gy in 4 fractions warrants consideration of prospective study of optimal treatment dosing regimens.

Transitional cell carcinoma arising in a pyelocaliceal cyst. An unusual cystic renal lesion with cytologic and imaging findings

The differentiation between benign and malignant cystic lesions of the kidney is a diagnostic challenge. Medical imaging aids in this task, but many cystic renal lesions require further work-up, frequently by computed tomography-guided fine needle aspiration. We report on the pathological findings in a case of moderately differentiated papillary transitional carcinoma, which arose in a pre-existing pyelocaliceal cyst in a 53-year-old man. In the case of this lesion, the distinction between a benign and a malignant renal cyst is blurred. To our knowledge, this is the third such occurrence to be reported and the first to be diagnosed by fine needle aspiration biopsy.

Adenoviral nerve growth factor and beta-galactosidase transfer to spinal cord: a behavioral and histological analysis

OBJECT

The present study characterizes the time course and loci of gene expression induced by the administration of adenoviral vectors into spinal cord. Although a marked inflammatory response to these vectors occurred, no effect on spinal cord function was seen in the 1st postoperative week. The expression of transgenic genes delivered by viral vectors is being exploited throughout the nervous system. The present study utilized adenoviral vectors containing the Rous sarcoma virus (RSV) promoter and a nuclear localization signal to achieve transgenic expression in mammalian spinal cord.

METHODS

Initial experiments utilizing the vector Ad.RSVlacZ (10(12) particles/ml) injected into the region of the central canal resulted in viral gene expression stretching over approximately 1.2 cm of spinal cord. Gene expression was first detected 3 days following viral administration and lasted until postinjection Day 14 with peak expression at Day 7. A variety of cell types in both white and gray matter expressed lacZ. Transgenic expression of the neurotrophin nerve growth factor (NGF) was achieved using injections of Ad.RSVNGF. On histological examination mononuclear inflammatory infiltrate and gliosis were revealed surrounding the injection sites of spinal cords receiving adenovirus but not vehicle. To assess spinal cord function during viral gene expression, animals previously trained in an operant runway task were tested at 7 days postinjection (the peak of viral gene expression) and demonstrated no changes in spinal cord function.

CONCLUSIONS

Results of this study using adenoviral neurotrophic gene transfer indicate that it provided an effective tool for the delivery of potentially therapeutic proteins to the injured or diseased spinal cord.

Repeat male genital self-mutilation precipitated by urinary complications of prior repair

Male genital self-mutilation is uncommon, with repeat mutilation even more rare. Our case is unique in that a urological complication of the first mutilating act (meatal stenosis) helped to precipitate the second incident. This case underscores the need not only for immediate urological and psychiatric care at the time of initial mutilation but also for close, combined followup care as well. In the majority of cases, when properly monitored, the men do not repeat the mutilating act.

Prostate biopsy in patients after proctectomy

Until the discovery of prostate specific antigen as a tool to detect prostate carcinoma, the rectum has always been necessary to allow the best evaluation and biopsy of the prostate, whether by digital examination or transrectal ultrasound. We describe a simple, accurate, computerized tomography-guided method to biopsy the prostate in men who have undergone proctectomy.

Risks of blood volume changes in hypogonadal men treated with testosterone enanthate for erectile impotence

Administration of anabolic steroids carries many risks. We present a series of 15 patients with primary hypogonadism who as a group had statistically significant increases in whole body hematocrit and red blood cell volume while on testosterone therapy of 300 mg. intramuscularly every 3 weeks. A small decrease in plasma volume over-all was not significant. Subsequent analyses compared subgroups whose whole body hematocrit during testosterone therapy was either 48% or greater (9) or less than 48% (6). Interaction effects indicated that the subgroups were similar when off testosterone but when on testosterone the former group exhibited an increase in red blood cell volume and a decrease in plasma volume, while the latter group had little change in either measurement. Subsequent to stopping testosterone therapy 2 patients in the whole body hematocrit 48% or greater group suffered strokes and 1 had transient ischemic attacks while on therapy. No one in the whole body hematocrit less than 48% group has had any cerebrovascular symptoms. Clinical implications, as well as cost-effective and practical suggestions for detecting possible dangerous hemoconcentration are discussed.

Metastatic carcinoma of prostate 23 years after radical prostatectomy

Carcinoma of the prostate may present with metastatic disease many years after treatment. We present a patient with adenocarcinoma of the prostate, "cured" by radical perineal prostatectomy in 1962, with the first signs of metastases presenting in 1985. This emphasizes the importance of long-term follow-up of patients with prostate carcinoma.

In treating impotence, urology and sex therapy are complementary

Urologists and mental health professionals are neither competitors nor adversaries. The principles of sex therapy represent a thoughtful and sensitive way to approach patients with almost any clinical problem so that they are more comfortable with the recommended tests or treatments. Sex therapy may be very helpful as an adjunct in treating "organic" as well as primarily emotional erectile dysfunction. We believe that with information we can help build a bridge between urologists and mental health professionals.

Sex reversal syndrome (XX male)

Men who appear normal and live a normal life, may have a 46,XX karyotype and present with the typical features of infertility and end organ (testicular) failure. They are azoospermic and their small testicles show specific patterns on light and electron microscopy. Recent advances in genetics (1) favor the "X-Y interchange" theory to explain this phenomenon; (2) hypothesize about the roles of the H-Y antigen and testis determining factor (TDF) in determining "maleness"; and (3) allow mapping of the relative positions of H-Y and TDF loci on the Y chromosome.

Use of the malleable penile prosthesis in the treatment of erectile dysfunction: a prospective study of postoperative adjustment

Much of the research on the postoperative adjustment of penile prosthesis recipients and their partners has been hampered by retrospective designs, unreliable assessment procedures and other methodological limitations. To address these shortcomings and to increase current knowledge regarding postoperative adjustment, we completed a prospective, longitudinal study of 19 implant recipients and their partners. Our results suggest that most patients and partners were satisfied with the prosthesis 1 year postoperatively, although use of the prosthesis sometimes was accompanied by short-term complications. Satisfaction tended to be lower among spouses than patients. Frequency of sexual intercourse increased during the followup period but there were no changes in sexual desire. Neither marital nor psychological adjustment changed significantly during this period.

Renal failure after intravesical mitomycin C

Severe side effects, local or systemic, are uncommon with intravesically administered mitomycin C. Bladder fibrosis and contracture, with resultant renal failure, are unusual but possible.

Single cylinder penile prosthesis

The single cylinder penile prosthesis is a viable procedure. It has many advantages. Its success depends on the careful selection, counseling, and follow-up of the patients and their partners.

Cutaneous vasostomy: technique for treatment of chronic and recurrent epididymitis

We describe a method for treatment of patients with chronic and recurrent epididymitis. Six of 7 patients (86%) treated with this procedure between 1977 and 1980 have had no recurrent episodes of epididymitis to date. We discuss the comparative benefits of this procedure as related to other surgical treatments for acute, chronic, and recurrent epididymitis.

Comparison of 99mTc phosphate and diphosphonate complexes in experimental renal infarcts

The 3-hour biodistribution of 99mTc complexes of five diphosphonates (HMDP, NMMDP, DMAD, DPD, and APD), imidodiphosphonate (IDP), and pyrophosphate (PYP) was compared in rats with segmental renal infarction induced by a 1-hour occlusion of a renal artery branch. 95mTc labeled MDP was a reference substance in all animals. Three agents (APD, HMDP and IDP) had a higher infarct/normal kidney concentration ratio than MDP, the latter two by virtue of a lower content in normal kidney. HMDP, DPD, and IDP had very high liver concentrations. DPD showed relatively high concentrations in soft tissues and blood. The blood and kidney levels of PYP were higher than those of MDP but the infarct/normal kidney ratios were similar. None of the agents had a higher uptake in bone than MDP: four had a significantly lower uptake. The increased concentration of 99mTc MDP in the infarcts was readily seen in camera images one day after renal artery occlusion, but not at three or seven days. Increased diphosphonate uptake was accompanied by an influx of calcium in both cortex and medulla. The accumulation of diphosphonate in areas of infarction was not modified by infusions of verapamil or Captopril.

The failed penile prosthetic implantation despite technical success

Successful implantation of a penile prosthesis involves more than an operation. Psychological factors can be crucial before, during and after the operation. If these issues are not addressed the true goal of restoring the pleasure of sexual intercourse will not be achieved, regardless of the type of prosthesis used or the technical success of the procedure.

Transcutaneous electrical nerve stimulator for stress incontinence

It has been shown that some patients with stress incontinence after prostatectomy may have significant improvement with electrical anal stimulation. The use of a transcutaneous stimulator is the easiest and least invasive method to try initially. Results may be quite satisfying whether the mechanism is physiologic or placebo. This is the first report of the use of transcutaneous electrical nerve stimulation in patients with stress incontinence.

The microgenesis of some renal calculi

We studied calcium oxalate stone formation in rats in which calculogenesis was induced by a diet deficient in pyridoxine (vitamin B6). We studied the sequence of stone formation using both a gross specimen transillumination technique, which is described, and histologic methods. A characteristic regional distribution of calculi is described and illustrated. Histologic studies reveal the interstitial site of calcium oxalate microlith formation. The progressive movement of these crystals through the tubular wall into the tubular lumen is described and illustrated. The formation of Randall's plaques is described and illustrated, as is a characteristic "geode" formation in the calyceal fornix. The significance of these findings is discussed and a new concept of stone formation proposed.

Evidence for a new mammalian organ. IV. Stone formation

We studied calcium oxalate stone formation in rats after calculogenesis had been induced by a diet deficient in pyridoxine (vitamin B6). Urinary calculi had formed within 6 weeks in 86 per cent of 114 animals. The calcium handling properties of 17 tissues (including the renal sinus "gland") were compared in normal and pyridoxine deficient animals. A significant increase in calcium (85Sr) uptake was found in the renal sinus "gland" and the renal medulla after pyridoxine deprivation. The movement of calcium from the perihilar sinus tissues into the renal medulla was examined and the significance of our observations is discussed.

Urodynamics of post-radical perineal prostatectomy incontinence

A series of post-radical perineal prostatectomy patients was studied by carbon dioxide cystometry. Of 30 patients questioned 17 were available for urodynamic assessment. All patients had shortened functional urethral lengths and decreased maximal closure pressures and incontinent patients had changes in the standing position. A review of the pertinent literature is presented. We believe that such studies in these patients can be clinically contributory and are of academic interest but history and cystourethroscopy remain more important in the over-all patient evaluation and care. With the ever-growing enthusiasm for urodynamics it is important to reveal its limitations as well as its benefits.

Fulminating hypercalcemia and markedly increased nephrogenous cyclic AMP in a patient with transitional cell carcinoma of the bladder

Refractory hypercalcemia developed suddenly in a patient who had undergone a radical cystectomy for an anaplastic transitional cell carcinoma of the bladder. A normal serum parathyroid hormone (PTH) value was obtained by immunoassay while the patient had hypercalcemia and unimpaired renal function. This normal PTH value in the presence of hypercalcemia was consistent with his hypercalcemia being secondary to excessive amounts of circulating PTH. The finding of increased nephrogenous cyclic AMP, however, provided the definitive diagnosis of hyyperparathyroidism. Since autopsy revealed that there was no residual tumor in the bladder area, only evidence of metastatic disease, and since the parathyroid glands were not hyperplastic or adenomatous, we attributed this patient's hypercalcemia to hyperparathyroidism due to the ectopic production of PTH by a metastasis from the transitional cell carcinoma of the bladder.

Evidence for a new mammalian organ. II. Calcium kinetics

The calcium content and calcium kinetics of the fatty tissue complex comprising the renal sinus organ of the rat kidney are reported. A comparison is made to control brown and white fat in the same animal. The calcium content of the renal sinus tissue is significantly greater than controls. Calcium localization in the mitochondria of the sinus tissue complex is demonstrated. Radioactive isotope studies (45Ca, 85Sr and 99mTc) indicate a dynamic exchange of calcium between the systemic pool and the sinus organ. Active accumulation appears to be operative. Supporting evidence for the existence of a portal vascular system joining the renal sinus complex and the renal parenchyma is presented. The significance of a calcium sink in the renal sinus tissue of the rat kidney is discussed.

Incapacitating flank pain of questionable renal origin

Local anesthetics can play a significant role in the diagnosis, and possible definitive treatment, of previously intractable flank pain. Numerous patients may thus be spared unnecessary physical and mental anguish, as well as unnecessary surgery.

The benign killer: carcinoma of the prostate

Radical prostatectomy has a significant role in the treatment of early stage carcinoma of the prostate, with a 6-fold difference in the radically and conservatively treated groups. Since 32 per cent of carcinomas will be missed even by experienced examiners on rectal examination, we believe that open perineal biopsy of the posterior lamella as described in 1968 would increase the yield of carcinoma and the subsequent cure by a radical operation. We have found that older patients do well with the perineal surgery--the extreme lithotomy position is no great problem and the postoperative course, without a painful abdominal wound, is less complicated.