A Comprehensive Review on the Working of a Radiation Oncology Facility During the Covid-19 Pandemic and Adapting it for South Asian Settings

Background: With the pandemic gaining a firm foothold globally, various governments world-wide are trying hard to halt its unprecedented spread. The pandemic is challenging the healthcare professionals in unique ways and forcing the frontline fighters to come up with dynamic changes in almost all disciplines of medical science. This article is aimed at a detailed review of the exist-ing guidelines for radiotherapy practice during this pandemic from across the world. Methods: This review has been organised under specific subheadings that pertains to the functioning of a Radiation Oncology facility in South Asian countries like India. After a detailed Zoom video conference between the authors, it was decided to focus the review under the following sub-headings: staff allocation, staff education, screening of patients, patient waiting area modifica-tion, patient selection, radiotherapy planning and execution, review of patients on radiotherapy, brachytherapy, inpatient admissions, follow up, resident training and treatment of suspected or positive COVID 19 patients.Results: After discussion among the authors, a consensus working suggestion during the COVID-19 pandemic has been proposed for a radiotherapy center in a South Asian country like India. All the authors worked simultaneously on a Google doc docu-ment to develop this manuscript. Conclusions: This paper can be a reference document for the functioning of a radiotherapy facility during the COVID19 pandemic. As the infrastructure of different institutes vary and so does each patient, the importance of fine tuning and tailoring our final decisions before treating a patient in this unprecedented crisis cannot be undermined.

ProCAID: A randomized double-blind phase II clinical trial of capivasertib (C) in combination with docetaxel and prednisolone chemotherapy (DP) in metastatic castration-resistant prostate cancer (mCRPC)

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Background: DP extends survival in mCRPC, but clinical benefit is modest. PI3K/AKT/PTEN pathway activation is common in mCRPC contributing to disease progression and DP resistance. C is a pan-AKT inhibitor. Pre-clinical data indicate activity in prostate cancer and synergism with DP. This phase II trial combined C with DP in mCRPC. Methods: Key eligibility criteria: histologically or cytologically proven measurable or evaluable mCRPC, suitable for treatment with DP for PSA and/or radiographic disease progression, ECOG performance status 0-1, no prior chemotherapy for mCRPC, not requiring insulin or > 2 oral hypoglycaemic drugs for diabetes mellitus. Treatment: up to 10 cycles of DP (D: 75 mg/m2 IV, day 1; P: 5 mg bd oral, day 1 – 21) and random assignment (1:1, double blind) to oral C (320 mg twice daily, 4 days on/3 days off, from cycle 1, day 2) or matched placebo to disease progression. Primary endpoint: progression free survival (PFS; comprising PSA, radiographic or clinical progression, new cancer therapy or death; PCWG2 criteria) in the intent to treat (ITT) population. Secondary endpoints included overall survival (OS) and safety. PFS and OS were also assessed by composite biomarker (B) subgroup for PI3K/AKT/PTEN pathway activation status (NGS/IHC on archival tumour, contemporaneous ctDNA). Statistics: designed to detect a 50% increase in median PFS (6 to 9 months (mo)) between the placebo and C arms (90% power, 20% 1-sided alpha) by Cox proportional hazards model. Registration: ISRCTN 69139368. Results: 150 patients were randomised to 01/2019. Median follow up 16.77 months (IQR 12.0-26.5). PFS and OS by ITT and B status, are shown in the table (NR, not reached; CI confidence interval). Grade 3–4 adverse events (AE) were equally common between arms (62.2%). The most common AEs were diarrhoea, fatigue and nausea. Conclusions: Adding C to DP did not extend PFS. The OS secondary endpoint was significantly increased. PFS and OS results were consistent irrespective of PI3K/AKT/PTEN pathway activation status. Clinical trial information: 69139368 . [Table: see text]

Pathological response rates and quality of life outcomes of neoadjuvant cabazitaxel and cisplatin chemotherapy for muscle-invasive transitional cell carcinoma of the urinary bladder

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Background: Neoadjuvant cisplatin-based combination chemotherapy (NAC) improves survival in muscle invasive bladder cancer (MIBC). However, response rates and survival remain suboptimal. We sought to evaluate the efficacy, safety and tolerability of cisplatin cabazitaxel combination in this patient group. Methods: A phase 2 single arm trial (Simon 2 stage), to recruit at least 26 evaluable patients was designed with 80% power to detect the primary endpoint, objective response rate (ORR) of > 35%. ORR was defined as pathological complete response (pCR) plus partial response (pathological downstaging), measured by pathologic staging (T2 or greater at diagnosis, to T1 or less at radical cystectomy). Treatment was with Cisplatin 70mg/m2 and Cabazitaxel 15mg/m2 on day 1 of a 21 day cycle, for 4 cycles prior to surgery. Toxicity was recorded using CTCAE v.4.03. Quality of Life (QoL) data were collected at baseline, prior to each cycle of chemotherapy and at 3-5 weeks after 4th cycle of chemotherapy using EQ-5D and EORTC QLQ-C30, BLM30 questionnaires. Results: Objective response was seen in 15 out of 26 evaluable patients, 57.7% and over a third of patients achieved pCR (9/26; 34.6%). 78% (21/27) of patients completed all cycles of treatment, with only 6.7% of the reported adverse events (AEs) being graded 3 or 4. There were 6 treatment related SAEs reported but no SUSARs. In patients who achieved objective response the median progression free (PFS) and overall survival (OS) were not reached (median follow up: 41.5m). In contrast, median PFS (7.2m) and OS (16.9m) were significantly worse (p = 0.001) in patients who did not respond. Response rates for EORTC QLQ-C30, BLM 30 and EQ5D questionnaires was 70.4, 70.4 & 63% respectively, at end of treatment. There was no significant difference in EORTC QLQ C30 summary, global health scores and EQ5D score with treatment. There was a significant decline in mean QLQ C30 domain scores after 1st cycle compared to baseline, but no further deterioration with subsequent cycles of chemotherapy. Conclusions: Cabazitaxel with cisplatin as NAC of MIBC can be considered a safe, well-tolerated and effective regimen with higher pCR rate of 34.6%. This compares favorably to that with Cisplatin/Gemcitabine (23-26%). Minimal changes in Global Health & EQ5D observed during NAC further demonstrates the excellent tolerability of this regimen and to our knowledge are the first data regarding QoL in NAC in MIBC. These results warrant further evaluation in a larger phase 3 study. Clinical trial information: 2011 004090 82 .

Single dose high-dose rate (HDR) brachytherapy (BT) as monotherapy for localised prostate cancer: Early results of a UK national cohort study

BACKGROUND

HDR brachytherapy alone is effective for the treatment of localised prostate cancer when given in 2-4 or more fractions. Single dose treatment has been explored in small cohort studies to date. This paper reports a large patient population with localised prostate cancer treated with single dose HDR brachytherapy delivering 19 Gy providing early outcome data from this approach.

PATIENTS AND METHODS

Seven centres across the UK collaborated in this national protocol to deliver 19 Gy to the PTV defined by the prostate capsule and a 3 mm expansion with clearly defined planning constraints for the urethra and rectum. Entry criteria allowed all risk groups provided PSA ≤40 µg/L and staging investigations were negative for metastases. The primary end point was biochemical relapse free survival (bRFS) defined using the Phoenix definition. Toxicity was measured using CTCAE v4.0.

RESULTS

A total of 441 patients were entered with median follow up 26 months (range 2-56). Median age was 73 (range 54-84) and 10% were low risk, 65% intermediate risk and 25% high risk. ADT was received by 37.6% overall and 90% of high risk patients for a median period of 6 months. Three year bRFS was overall 88%: this was 100% in low risk, 86% in intermediate risk and 75% in high risk. Only Gleason score was an independent predictor of bRFS. Relapse in 25 patients was assessed radiologically and occurred in the prostate in 15 of these, 11 of whom had localised prostate relapse only. Acute toxicity was low with no grade 3 or 4 events; there were two cases of late urinary stricture and two grade 3 late rectal events.

CONCLUSION

This is the largest cohort of single dose HDR brachytherapy patients treated with a single dose published to date. It shows that with 19 Gy there is 100% bRFS at 3 years in low risk patients but results in intermediate and high risk groups are less encouraging falling to 86% and 75% at 3 years with relapse predominantly in the prostate. Limited by the short follow up period of this study, the long-term outcomes of this single dose HDR approach remains uncertain. It is important to have close ongoing surveillance of this cohort as the data matures.

Prostate cancer androgen receptor splice variant 7 biomarker study - a multicentre randomised feasibility trial of biomarker-guided personalised treatment in patients with advanced prostate cancer (the VARIANT trial) study protocol

INTRODUCTION

Prostate cancer is the most common male cancer with one in four developing non-curable metastatic disease. Initial treatment responses to hormonal therapies are transient and further management options lie between (1) further hormone therapy or (2) a non-hormonal approach involving additional chemotherapy or molecular radiotherapy (radium-223). There is no clear rationale for choosing between these mechanistically different treatment approaches. The biology of hormone resistance is driven through abnormal androgen receptor activity and we can assay this through a blood test measuring androgen receptor variant 7 (AR-V7) expression in circulating tumour cells. Despite increasing evidence supporting AR-V7's role as a prognostic marker, the clinical utility of such measures remains unknown in helping personalise treatment decisions.

METHODS AND DESIGN

The VARIANT feasibility trial is a pragmatic design, to be run over 18 months with participants randomised into the intervention arm receiving biomarker (AR-V7) guided clinical treatment and participants randomised into the control arm with conventional standard management (no biomarker guidance). AR-V7 positive participants (likely to be insensitive to further hormone treatment) will receive chemotherapy or in other cases radium-223 (where routinely available). Seventy male ≥18 years old participants with metastatic castrate resistant prostate cancer clinically indicated to proceed to further hormone therapy or chemotherapy, will be recruited from three National Health Service Trusts based in England, Scotland and Wales. The feasibility primary outcome is willingness of patients to be randomised and clinicians to recruit to a biomarker-based treatment strategy, with trial data informing the basis of a definitive and appropriately powered randomised control trial.

ETHICS AND DISSEMINATION

Formal ethics review was undertaken with a favourable opinion, through Wales NRES Committee 2 18/WA/0419. Findings to be disseminated through patient and professional organisations that have expressed their support, media outlets and peer-reviewed journal publication.

TRIAL REGISTRATION NUMBER

ISRCTN10246848; pre-results.

Evaluation of Multimodality Management of Adenoid Cystic Carcinoma of the Head and Neck

Adenoid cystic carcinoma is a relatively rare tumour arising from salivary glands of head and neck region. Surgery and radiotherapy form standard treatment modalities in the management of this tumor. In this analysis we present results of multimodality treatment in our cohort of patient. This retrospective analysis evaluated results of treatment in forty patients diagnosed with adenoid cystic carcinoma of the head and neck. Evaluation was done to identify prognostic factors affecting the disease free survival. A median disease free survival of 34 ± 2.42 (Median ± SE) versus 10 ± 5.45 months was seen in patients undergoing surgery followed by post operative radiotherapy versus radiotherapy alone (P = 0.01). A radiotherapy dose more than 60 Gy was associated with a better disease free survival compared with patients receiving less than 60 Gy (P = 0.01). Positive surgical margins and perineural invasion were associated with a poor treatment outcome (P = 0.02) Patients with c-kit positive status showed a poor local control rate (P = 0.05).

Phase II randomised control feasibility trial of a nutrition and physical activity intervention after radical prostatectomy for prostate cancer

OBJECTIVE

Dietary factors and physical activity may alter prostate cancer progression. We explored the feasibility of lifestyle interventions following radical prostatectomy for localised prostate cancer.

DESIGN

Patients were recruited into a presurgical observational cohort; following radical prostatectomy, they were offered randomisation into a 2×3 factorial randomised controlled trial (RCT).

SETTING

A single National Health Service trust in the South West of England, UK.

PARTICIPANTS

Those with localised prostate cancer and listed for radical prostatectomy were invited to participate.

RANDOMISATION

Random allocation was performed by the Bristol Randomised Trial Collaboration via an online system.

INTERVENTIONS

Men were randomised into both a modified nutrition group (either increased vegetable and fruit, and reduced dairy milk; or lycopene supplementation; or control) and a physical activity group (brisk walking or control) for 6 months.

BLINDING

Only the trial statistician was blind to allocations.

PRIMARY OUTCOME MEASURES

Primary outcomes were measures of feasibility: randomisation rates and intervention adherence at 6 months. Collected at trial baseline, three and six months, with daily adherence reported throughout. Our intended adherence rate was 75% or above, the threshold for acceptable adherence was 90%.

RESULTS

108 men entered the presurgical cohort, and 81 were randomised into the postsurgical RCT (randomisation rate: 93.1%) and 75 completed the trial. Of 25 men in the nutrition intervention, 10 (40.0%; 95% CI 23.4% to 59.3%) adhered to the fruit and vegetable recommendations and 18 (72.0%; 95% CI 52.4% to 85.7%) to reduced dairy intake. Adherence to lycopene (n=28), was 78.6% (95% CI 60.5% to 89.8%), while 21/39 adhered to the walking intervention (53.8%; 95% CI 38.6% to 68.4%). Most men were followed up at 6 months (75/81; 92.6%). Three 'possibly related' adverse events were indigestion, abdominal bloating and knee pain.

CONCLUSIONS

Interventions were deemed feasible, with high randomisation rates and generally good adherence. A definitive RCT is proposed.

TRIAL REGISTRATION NUMBER

ISRCTN 99048944.

Measuring testosterone and testosterone replacement therapy in men receiving androgen deprivation therapy for prostate cancer: A survey of UK uro-oncologists' opinions and practice

AIM

To explore the practice and attitudes of uro-oncologists in the UK regarding monitoring testosterone levels and the use of testosterone replacement therapy (TRT) in their prostate cancer patients treated with androgen deprivation therapy (ADT).

METHODS

An expert-devised online questionnaire was completed by the members of the British Uro-oncology Group (BUG).

RESULTS

Of 160 uro-oncologists invited, 84 completed the questionnaire. Before initiating ADT in patients with non-metastatic prostate cancer, only 45% of respondents measured testosterone levels and 61% did not measure testosterone at all during ADT in the adjuvant or neoadjuvant setting. However, in men with metastatic prostate cancer, 71% of the uro-oncologists measured testosterone before starting ADT and the majority continued testing during treatment. Approximately two-thirds of respondents did not prescribe TRT for their patients who were in remission following neo(adjuvant) ADT and who had castration levels of testosterone.

DISCUSSION

Among UK uro-oncologists, the measurement of testosterone levels before and during ADT was not typically part of routine practice in the management of patients with prostate cancer. However, testosterone levels were checked more frequently for patients with metastatic disease than disease at an earlier stage. Testing could be conducted in parallel with PSA measurement as testosterone levels are linked to biochemical failure. The majority of specialists participating in the survey did not prescribe TRT for their patients in remission following ADT.

CONCLUSION

Uro-oncologists in the UK do not generally measure testosterone as part of their patient management and they remain cautious about the possible benefits of TRT in men with prostate cancer.

Comparison of Venous Thrombosis Complications in Midlines Versus Peripherally Inserted Central Catheters: Are Midlines the Safer Option?

Catheter-related (CR) thrombosis is a significant complication of midline catheters (MCs) and peripherally inserted central catheters (PICCs). Limited existing data for MCs suggest a favorable complication profile for MCs. To compare incidence of CR thrombosis between MCs and PICCs and to evaluate the impact of quantity of lumens and catheter diameter on CR thrombosis. This was a retrospective comparison spanning 13 months of MCs and PICCs for symptomatic CR thrombosis at an 1100 bed tertiary care academic medical center. Adult patients who had an MC or a PICC placed by the were included. Data were collected using the electronic medical record. Statistical analysis was performed using SAS software. A total of 2577 catheters were included in the analysis with 1094 MCs and 1483 PICCs. One hundred thirty (11.88%) MCs developed CR thrombosis (deep vein thrombosis [DVT] or superficial venous thrombophlebitis [SVT]) as compared to 112 (6.88%) PICCs (odds ratio [OR]: 1.82; P < .0001). Midline catheters had a 53% greater odds of developing CR DVT than PICCs (7.04% MCs and 4.72% PICCs; OR: 1.53; P = .0126). For CR SVT, MCs have a 2.29-fold greater odds of developing CR SVT than PICCs (4.84% MCs and 2.16% PICCs; OR: 2.29; P = .0002). For MCs and PICCs, the incidence of CR thrombosis was 13.50% for double lumen/5F lines and was 6.92% for single lumen/4F lines (OR: 2.10; P = <.0001). Symptomatic CR thrombosis is a serious, life-threatening complication that occurs more frequently in MCs compared to PICCs. Inserters should consider placement of single lumen catheters with the smallest diameter to reduce this risk when a midline is used.

Single Versus Double Tourniquet Technique for Ultrasound-Guided Venous Catheter Placement

Introduction

Peripheral, ultrasound-guided intravenous (IV) access occurs frequently in the emergency department, but certain populations present unique challenges for successfully completing this procedure. Prior research has demonstrated decreased compressibility under double tourniquet technique (DT) compared with single tourniquet (ST). We hypothesized that catheters inserted under DT method would have a higher first-stick success rate compared with those inserted under ST method.

Methods

We randomized 100 patients with a history of difficult IV access, as defined by past ultrasound IV, prior emergency visit with two or more attempts required for vascular access, history of IV drug abuse, history of end stage renal disease on hemodialysis or obesity, to ultrasound-guided IV placement under either DT or ST method. We measured the vein characteristics measured under ultrasound, and recorded the number of attempts and location of attempts at vascular access.

Results

Of an initial 100 patients enrolled, we analyzed a total of 99 with 48 placed under ST and 51 placed under DT. Attending physicians inserted 41.7% of ST and 41.2% of DT, with non-attending inserters (including residents, nurses, and technicians) inserted the remainder. First-stick success rate was observed at 64.3% in ST and 66.7% in DT (p=0.93). Attendings had an overall higher first-stick success rate (95.1%) compared to non-attending inserters (65.5%) (p=<0.001). The average vein depth measured in ST was 0.73 centimeters (cm) compared with 0.87 cm in DT (p=0.02).

Conclusion

DT technique did not produce a measureable increase in first-stick success rate compared to ST, including after adjusting for level of training of inserter. However, a significant difference in average vein depth between the study arms may have limited the reliability of our overall results. Future studies controlling for this variable may be required to more accurately compare these two techniques.

Body image issues and attitudes towards exercise amongst men undergoing androgen deprivation therapy (ADT) following diagnosis of prostate cancer

BACKGROUND

Androgen deprivation therapy (ADT) is an established treatment for prostate cancer (PCa), but its side-effects can affect body appearance and functioning. However, research into the impact of ADT on body image is limited. Exercise can help patients to counterbalance some side-effects, potentially improving body image too. However, adherence to exercise recommendations is low. Therefore, we explored body image after ADT and attitudes towards exercise.

METHODS

Twenty two semi-structured interviews were conducted with PCa patients receiving ADT (M_age = 67.9 years old, SD = 9.99).

RESULTS

Participants expressed appearance dissatisfaction focusing on body feminization. Participants exercised to counterbalance ADT side-effects and improve mood. Exercise also helped them to re-establish a sense of control over their body and experience a sense of achievement. However, some men described being worried that their appearance and physical performance would be judged by others, so they often exercised alone or gave up exercise. Time management and fatigue were also identified as exercise barriers.

CONCLUSION

These findings highlight the need to further investigate body image concerns and exercise barriers in PCa patients undergoing ADT. These results could also inform support groups and health care professionals on the topic. However, further research should explore the most effective and acceptable ways to provide support to PCa patients on body image issues.

Kilovoltage cone-beam computed tomography imaging dose estimation and optimization: Need of daily cone-beam computed tomography

Aim

The aim of the present study was to access the need of daily cone-beam computed tomography (CBCT) and the requirement of in-house protocols of image acquisition frequency to reduce unnecessary exposure to the patients undergoing radiotherapy treatment.

Materials and Methods

The dose delivered during CBCT procedure (On-Board Imager, Trilogy, Varian medical system, Inc., Palo Alto, California) was assessed for pelvic and head and neck region. For dose estimation, cylindrical polymethyl methacrylate phantoms of 15 cm length, 16 cm, and 32 cm diameter were used to simulate the patient's head and neck and pelvic region thickness, respectively. More than 10 cm scatterer was added on either end of this phantom. Calibrated Ionization chamber DCT10 LEMO SN 1685 iba, dosimetry, Germany (10 cm active length) was used to measure the dose Index. The doses known as cone-beam dose index (CBDI₁₀₀) were estimated for all the scanning protocols (kV and mAs setting) available on the machine. In this study, image acquisition frequency to correct the setup error was optimized. In-house protocol for image acquisition frequency during treatment has been suggested to reduce the dose. It was based on the principle of as low as reasonable achievable.

Results

Optimized dose protocol observed was the "standard dose head" for which the CBDI₁₀₀ was 2.43 mGy. Whereas for pelvic imaging, single protocol of 125 kV, 80 mA was available by which a dose of 7.61 mGy is likely to be received by the patient during scan. Maximum shift of 6 mm in lateral direction was observed to the patient of Pelvis region and 5 mm was observed in the longitudinal direction for the H and N patients. Angular shift measured in patient position was 3.8° and 3.1° for H and N and pelvic region, respectively.

Conclusion

Three consecutive-day CBCT-imaging at the beginning of the treatment followed by once weekly CBCT and two-dimensional (2D) imaging in remaining days of treatment can be an optimized way of imaging for the patient having malignancy in the region of pelvic and abdomen. For H and N, once in a week, CBCT with standard dose head protocol, followed by 2D-imaging in remaining days can be an optimized way of imaging.

Alternative Chemotherapy Schedules in Ewing's Sarcoma: An Indian Perspective

Advances in the treatment of Ewing's sarcoma family of tumors (ESFTs) are a result of improvements in systemic and local therapies. VACA (vincristine, Adriamycin [doxorubicin], cyclophosphamide, dactinomycin) chemotherapy alone versus VACA + IE (VACA with alternate ifosfamide, etoposide) improve survival, but this regimen cannot be given to all patients due to poor tolerance and 5-day schedule chemotherapy in VACA + IE schedule. We reviewed the records of 50 patients treated as per our institutional protocols from 2007 to 2011. Two schedules of chemotherapy followed were vincristine, Adriamycin, cyclophosphamide (VAC) and VAC with alternate ifosfamide, etoposide (VAC + IE). Factors predictive of local failure and distant recurrence were analyzed. A total of 50 patients were analyzed. The median age at diagnosis was 14 years. Thirty-two patients were male, whereas 18 were female. Approximately, 95% of the patients relapsed after a median time gap of 1.6 years. The median 5-year disease-free survival was 30%. Systemic treatment with VAC or VAC + IE–based chemotherapy had equal local control and distant control rates. Smaller tumors had a better local control and lesser systemic failure than those of larger sizes. Successful treatment of Ewing's sarcoma requires optimal systemic and local therapy. Both the chemotherapy regimens showed equal survival rates. Control of both the local and distant diseases is a result of the combined modality approach. Stage at presentation is the most important factor for prognosis. Complete surgery and local radiotherapy are important predictive factors for local and systemic control.

Clinical progression at initiation of a life-extending therapy (LET) in metastatic castration-resistant prostate cancer (mCRPC) is associated with a poor prognosis, whatever the treatment-line: Results of the CATS retrospective registry

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Background: We previously reported that cancer pain was associated with a poor prognosis in mCRPC patients (pts) treated with docetaxel (D) ( Oudard, BJU Int 2009). Asymptomatic chemo-naive pts treated with novel androgen receptor targeted agent (H) have a greater overall survival (OS) than those with mild symptoms ( Miller, Eur Urol 2018). We thus investigated the impact on OS of progression type at initiation of first-, second- and third-line of LET in a large cohort of mCRPC pts (CATS registry) treated with D, cabazitaxel (C) and H. Methods: 669 consecutive mCRPC pts treated with 3 LETs (DCH, n= 158; DHC, n=456; HDC, n=55) were retrospectively reviewed. Type of progression: PSA alone, radiographic ± PSA, clinical ± PSA ± radiographic at initiation of each LET was evaluable in 661 pts. Clinical progression was defined by worsening of cancer-related pain or symptoms as per physician judgment. Results: Clinical progression at initiation of LET increased with the number of treatment lines and was consistently associated with a worse outcome. Clinical progression was associated with a significantly shorter duration of treatment with H but had no influence on duration of taxanes. Conclusions: In pts treated with 3 LTEs (D, C and H) clinical progression at sequence initiation is associated with a poor OS and a shorter duration of hormonal treatment. These data may help guide treatment decisions.[Table: see text]

Adenoid Cystic Carcinoma of Buccal Mucosa: Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Detection and Biopsy of Pulmonary Metastases and Assessment of Treatment Response

Adenoid cystic carcinoma of the buccal mucosa has an increased propensity for recurrence and distant metastases. Due to the poor prognosis at late detection of distant metastases, it is advisable to keep a close follow-up. In the present case, ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography proved invaluable in the comprehensive workup of the patient, including detection of local recurrence, distant metastases, and in assessing treatment response.

Analysis of volumetric and dosimetric changes in mid treatment CT scan in carcinoma nasopharynx: implications for adaptive radiotherapy

Carcinoma of nasopharynx is a radiosensitive tumor and therapeutic response during radiation treatment can result in dosimetric variations in the delivered dose to the tumor and critical organs. This study was done to evaluate the volumetric and dosimetric changes seen in tumor tissue and organs at risk in a mid treatment planning scan and its implications for adaptive replanning. Twenty patients of locally advanced carcinoma nasopharynx were evaluated. All patients were started on treatment with a baseline treatment plan on SIB-VMAT. To evaluate volumetric and dosimetric changes during treatment, a mid treatment CT scan (MTS) was taken at the 17^th fraction of treatment and compared with the baseline planning CT scan (BS). Adaptive treatment plans were generated on the MTS and further treatment was continued on the adaptive plans. The mean weight loss observed at the 17th fraction of treatment was 3.4 ± 2.6 kg(Mean±S.D). The mean neck diameter at C2 level was 14.19±1.02 and 13.29 ± 1.14 cm in the BS and MTS respectively (p=0.001). The GTV 70 volume showed a 29.16% volume loss. The mean doses received by the right and left parotids were 25.45±0.98 and 24.64±3.8 Gy in the baseline treatment plan and 33.21±11.29 (p=0.054) and 31.76±8.44 Gy respectively in the MTS (p=0.016) The mean weight loss showed a statistically significant correlation with increase in the right parotid(p=0.043) and left parotid doses(p=0.024). Weight loss during treatment combined with volume changes in target tissues mandate routine adaptive replanning while treating carcinoma nasopharynx.